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Sample records for electrical neuroimaging evidence

  1. Ventral and dorsal visual pathways support auditory motion processing in the blind: evidence from electrical neuroimaging.

    PubMed

    Lewald, Jörg; Getzmann, Stephan

    2013-10-01

    Blindness induces processes of neural plasticity, resulting in recruitment of the deafferentated visual areas for non-visual sensory functions. These processes are related to superior abilities of blind compared with sighted individuals for specific auditory and tactile tasks. Recently, an exceptional performance of the blind has been demonstrated for auditory motion perception, with a minimum audible movement angle that was half that of sighted controls (J. Lewald (2013) Neuropsychologia, 51, 181-186). The present study revealed an electrophysiological correlate of this finding by analysing the so-called motion-onset response, a prominent auditory-evoked potential to the onset of motion. The cN1 component of this response, appearing about 170 ms after motion onset, was two times higher in amplitude for blind compared with matched sighted control subjects. At the time of the cN1, electrical neuroimaging using sLORETA revealed stronger activation in blind than sighted subjects primarily in ventral visual areas (V1v, V2v, VP, V4v) of the right occipital lobe. Activation was also obtained in middle temporal area V5. These findings suggest that blindness results in stronger involvement of both non-motion areas of the ventral visual stream and motion areas of the dorsal visual stream in processing of auditory motion at the same point in time after motion onset. This argues against the view that visual motion areas, such as area V5, are preferentially recruited for auditory motion analysis in the blind. Rather, cross-modal reorganization of cortical areas induced by blindness seems to be largely independent of the specific visual functions of the same areas in sighted persons. PMID:23859484

  2. Understanding the impact of TV commercials: electrical neuroimaging.

    PubMed

    Vecchiato, Giovanni; Kong, Wanzeng; Maglione, Anton Giulio; Wei, Daming

    2012-01-01

    Today, there is a greater interest in the marketing world in using neuroimaging tools to evaluate the efficacy of TV commercials. This field of research is known as neuromarketing. In this article, we illustrate some applications of electrical neuroimaging, a discipline that uses electroencephalography (EEG) and intensive signal processing techniques for the evaluation of marketing stimuli. We also show how the proper usage of these methodologies can provide information related to memorization and attention while people are watching marketing-relevant stimuli. We note that temporal and frequency patterns of EEG signals are able to provide possible descriptors that convey information about the cognitive process in subjects observing commercial advertisements (ads). Such information could be unobtainable through common tools used in standard marketing research. Evidence of this research shows how EEG methodologies could be employed to better design new products that marketers are going to promote and to analyze the global impact of video commercials already broadcast on TV. PMID:22678840

  3. Linking Essential Tremor to the Cerebellum-Neuroimaging Evidence.

    PubMed

    Cerasa, Antonio; Quattrone, Aldo

    2016-06-01

    Essential tremor (ET) is the most common pathological tremor disorder in the world, and post-mortem evidence has shown that the cerebellum is the most consistent area of pathology in ET. In the last few years, advanced neuroimaging has tried to confirm this evidence. The aim of the present review is to discuss to what extent the evidence provided by this field of study may be generalised. We performed a systematic literature search combining the terms ET with the following keywords: MRI, VBM, MRS, DTI, fMRI, PET and SPECT. We summarised and discussed each study and placed the results in the context of existing knowledge regarding the cerebellar involvement in ET. A total of 51 neuroimaging studies met our search criteria, roughly divided into 19 structural and 32 functional studies. Despite clinical and methodological differences, both functional and structural imaging studies showed similar findings but without defining a clear topography of neurodegeneration. Indeed, the vast majority of studies found functional and structural abnormalities in several parts of the anterior and posterior cerebellar lobules, but it remains to be established to what degree these neural changes contribute to clinical symptoms of ET. Currently, advanced neuroimaging has confirmed the involvement of the cerebellum in pathophysiological processes of ET, although a high variability in results persists. For this reason, the translation of this knowledge into daily clinical practice is again partially limited, although new advanced multivariate neuroimaging approaches (machine-learning) are proving interesting changes of perspective. PMID:26626626

  4. A cognitive neurobiological account of deception: evidence from functional neuroimaging.

    PubMed Central

    Spence, Sean A; Hunter, Mike D; Farrow, Tom F D; Green, Russell D; Leung, David H; Hughes, Catherine J; Ganesan, Venkatasubramanian

    2004-01-01

    An organism may use misinformation, knowingly (through deception) or unknowingly (as in the case of camouflage), to gain advantage in a competitive environment. From an evolutionary perspective, greater tactical deception occurs among primates closer to humans, with larger neocortices. In humans, the onset of deceptive behaviours in childhood exhibits a developmental trajectory, which may be regarded as 'normal' in the majority and deficient among a minority with certain neurodevelopmental disorders (e.g. autism). In the human adult, deception and lying exhibit features consistent with their use of 'higher' or 'executive' brain systems. Accurate detection of deception in humans may be of particular importance in forensic practice, while an understanding of its cognitive neurobiology may have implications for models of 'theory of mind' and social cognition, and societal notions of responsibility, guilt and mitigation. In recent years, functional neuroimaging techniques (especially functional magnetic resonance imaging) have been used to study deception. Though few in number, and using very different experimental protocols, studies published in the peer-reviewed literature exhibit certain consistencies. Attempted deception is associated with activation of executive brain regions (particularly prefrontal and anterior cingulate cortices), while truthful responding has not been shown to be associated with any areas of increased activation (relative to deception). Hence, truthful responding may comprise a relative 'baseline' in human cognition and communication. The subject who lies may necessarily engage 'higher' brain centres, consistent with a purpose or intention (to deceive). While the principle of executive control during deception remains plausible, its precise anatomy awaits elucidation. PMID:15590616

  5. The Human Amygdala and Pain: Evidence from Neuroimaging

    PubMed Central

    Simons, Laura; Moulton, Eric A.; Linnman, Clas; Carpino, Elizabeth; Becerra, Lino; Borsook, David

    2014-01-01

    The amygdala, a small deep brain structure involved in behavioral processing through interactions with other brain regions, has garnered increased attention in recent years in relation to pain processing. As pain is a multidimensional experience that encompasses physical sensation, affect, and cognition, the amygdala is well suited to play a part in this process. Multiple neuroimaging studies of pain in humans have reported activation in the amygdala. Here we summarize these studies by performing a coordinate-based meta-analysis within experimentally induced and clinical pain studies using an activation likelihood estimate analysis. The results are presented in relation to locations of peak activation within and outside of amygdala subregions. The majority of studies identified coordinates consistent with human amygdala cytoarchitecture indicating reproducibility in neuroanatomical labeling across labs, analysis methods, and imaging modalities. Differences were noted between healthy and clinical pain studies: in clinical pain studies, peak activation was located in the laterobasal region, suggestive of the cognitive-affective overlay present among individuals suffering from chronic pain; while the less understood superficial region of the amygdala was prominent among experimental pain studies. Taken together, these findings suggest several important directions for further research exploring the amygdala’s role in pain processing. PMID:23097300

  6. The human amygdala and pain: evidence from neuroimaging.

    PubMed

    Simons, Laura E; Moulton, Eric A; Linnman, Clas; Carpino, Elizabeth; Becerra, Lino; Borsook, David

    2014-02-01

    The amygdala, a small deep brain structure involved in behavioral processing through interactions with other brain regions, has garnered increased attention in recent years in relation to pain processing. As pain is a multidimensional experience that encompasses physical sensation, affect, and cognition, the amygdala is well suited to play a part in this process. Multiple neuroimaging studies of pain in humans have reported activation in the amygdala. Here, we summarize these studies by performing a coordinate-based meta-analysis within experimentally induced and clinical pain studies using an activation likelihood estimate analysis. The results are presented in relation to locations of peak activation within and outside of amygdala subregions. The majority of studies identified coordinates consistent with human amygdala cytoarchitecture indicating reproducibility in neuroanatomical labeling across labs, analysis methods, and imaging modalities. Differences were noted between healthy and clinical pain studies: in clinical pain studies, peak activation was located in the laterobasal region, suggestive of the cognitive-affective overlay present among individuals suffering from chronic pain; while the less understood superficial region of the amygdala was prominent among experimental pain studies. Taken together, these findings suggest several important directions for further research exploring the amygdala's role in pain processing. PMID:23097300

  7. Gene X Environment Interactions in Schizophrenia and Bipolar Disorder: Evidence from Neuroimaging

    PubMed Central

    Geoffroy, Pierre Alexis; Etain, Bruno; Houenou, Josselin

    2013-01-01

    Introduction: Schizophrenia (SZ) and Bipolar disorder (BD) are considered as severe multifactorial diseases, stemming from genetic and environmental influences. Growing evidence supports gene x environment (GxE) interactions in these disorders and neuroimaging studies can help us to understand how those factors mechanistically interact. No reviews synthesized the existing data of neuroimaging studies in these issues. Methods: We conduct a systematic review on the neuroimaging studies exploring GxE interactions relative to SZ or BD in PubMed. Results: First results of the influence of genetic and environmental risks on brain structures came from monozygotic twin pairs concordant and discordant for SZ or BD. Few structural magnetic resonance imaging (sMRI) studies have explored the GxE interactions. No other imaging methods were found. Two main GxE interactions on brain volumes have arisen. First, an interaction between genetic liability to SZ and obstetric complications on gray matter, cerebrospinal fluid, and hippocampal volumes. Second, cannabis use and genetic liability interaction effects on cortical thickness and white matter volumes. Conclusion: Combining GxE interactions and neuroimaging domains is a promising approach. Genetic risk and environmental exposures such as cannabis or obstetrical complications seem to interact leading to specific neuroimaging cerebral alterations in SZ. They are suggestive of GxE interactions that confer phenotypic abnormalities in SZ and possibly BD. We need further, larger neuroimaging studies of GxE interactions for which we may propose a framework focusing on GxE interactions data already known to have a clinical effect such as infections, early stress, urbanicity, and substance abuse. PMID:24133464

  8. State dependency of inhibitory control performance: an electrical neuroimaging study.

    PubMed

    De Pretto, Michael; Sallard, Etienne; Spierer, Lucas

    2016-07-01

    Behavioral and brain responses to stimuli not only depend on their physical features but also on the individuals' neurocognitive states before stimuli onsets. While the influence of pre-stimulus fluctuations in brain activity on low-level perceptive processes is well established, the state dependency of high-order executive processes remains unclear. Using a classical inhibitory control Go/NoGo task, we examined whether and how fluctuations in the brain activity during the period preceding the stimuli triggering inhibition influenced inhibitory control performance. Seventeen participants completed the Go/NoGo task while 64-channel electroencephalogram was recorded. We compared the event-related potentials preceding the onset of the NoGo stimuli associated with inhibition failures false alarms (FA) vs. successful inhibition correct rejections (CR) with data-driven statistical analyses of global measures of the topography and strength of the scalp electric field. Distributed electrical source estimations were used to localize the origin of the event-related potentials modulations. We observed differences in the global field power of the event-related potentials (FA > CR) without concomitant topographic modulations over the 40 ms period immediately preceding NoGo stimuli. This result indicates that the same brain networks were engaged in the two conditions, but more strongly before FA than CR. Source estimations revealed that this effect followed from a higher activity before FA than CR within bilateral inferior frontal gyri and the right inferior parietal lobule. These findings suggest that uncontrolled quantitative variations in pre-stimulus activity within attentional and control brain networks influence inhibition performance. The present data thereby demonstrate the state dependency of cognitive processes of up to high-order executive levels. PMID:27116703

  9. Neuroimaging evidence of deficient axon myelination in Wolfram syndrome

    PubMed Central

    Lugar, Heather M.; Koller, Jonathan M.; Rutlin, Jerrel; Marshall, Bess A.; Kanekura, Kohsuke; Urano, Fumihiko; Bischoff, Allison N.; Shimony, Joshua S.; Hershey, Tamara; Austin, P.; Beato, B.; Bihun, E.; Doty, T.; Earhart, G.; Eisenstein, S.; Hoekel, J.; Karzon, R.; Licis, A.; Manwaring, L.; Paciorkowski, A. R.; Pepino de Gruev, Y.; Permutt, A.; Pickett, K.; Ranck, S.; Reiersen, A.; Tychsen, L.; Viehoever, A.; Wasson, J.; White, N. H.

    2016-01-01

    Wolfram syndrome is a rare autosomal recessive genetic disease characterized by insulin dependent diabetes and vision, hearing and brain abnormalities which generally emerge in childhood. Mutations in the WFS1 gene predispose cells to endoplasmic reticulum stress-mediated apoptosis and may induce myelin degradation in neuronal cell models. However, in vivo evidence of this phenomenon in humans is lacking. White matter microstructure and regional volumes were measured using magnetic resonance imaging in children and young adults with Wolfram syndrome (n = 21) and healthy and diabetic controls (n = 50). Wolfram patients had lower fractional anisotropy and higher radial diffusivity in major white matter tracts and lower volume in the basilar (ventral) pons, cerebellar white matter and visual cortex. Correlations were found between key brain findings and overall neurological symptoms. This pattern of findings suggests that reduction in myelin is a primary neuropathological feature of Wolfram syndrome. Endoplasmic reticulum stress-related dysfunction in Wolfram syndrome may interact with the development of myelin or promote degeneration of myelin during the progression of the disease. These measures may provide objective indices of Wolfram syndrome pathophysiology that will be useful in unraveling the underlying mechanisms and in testing the impact of treatments on the brain. PMID:26888576

  10. Neuroimaging evidence of deficient axon myelination in Wolfram syndrome.

    PubMed

    Lugar, Heather M; Koller, Jonathan M; Rutlin, Jerrel; Marshall, Bess A; Kanekura, Kohsuke; Urano, Fumihiko; Bischoff, Allison N; Shimony, Joshua S; Hershey, Tamara

    2016-01-01

    Wolfram syndrome is a rare autosomal recessive genetic disease characterized by insulin dependent diabetes and vision, hearing and brain abnormalities which generally emerge in childhood. Mutations in the WFS1 gene predispose cells to endoplasmic reticulum stress-mediated apoptosis and may induce myelin degradation in neuronal cell models. However, in vivo evidence of this phenomenon in humans is lacking. White matter microstructure and regional volumes were measured using magnetic resonance imaging in children and young adults with Wolfram syndrome (n = 21) and healthy and diabetic controls (n = 50). Wolfram patients had lower fractional anisotropy and higher radial diffusivity in major white matter tracts and lower volume in the basilar (ventral) pons, cerebellar white matter and visual cortex. Correlations were found between key brain findings and overall neurological symptoms. This pattern of findings suggests that reduction in myelin is a primary neuropathological feature of Wolfram syndrome. Endoplasmic reticulum stress-related dysfunction in Wolfram syndrome may interact with the development of myelin or promote degeneration of myelin during the progression of the disease. These measures may provide objective indices of Wolfram syndrome pathophysiology that will be useful in unraveling the underlying mechanisms and in testing the impact of treatments on the brain. PMID:26888576

  11. Learning-induced plasticity in auditory spatial representations revealed by electrical neuroimaging.

    PubMed

    Spierer, Lucas; Tardif, Eric; Sperdin, Holger; Murray, Micah M; Clarke, Stephanie

    2007-05-16

    Auditory spatial representations are likely encoded at a population level within human auditory cortices. We investigated learning-induced plasticity of spatial discrimination in healthy subjects using auditory-evoked potentials (AEPs) and electrical neuroimaging analyses. Stimuli were 100 ms white-noise bursts lateralized with varying interaural time differences. In three experiments, plasticity was induced with 40 min of discrimination training. During training, accuracy significantly improved from near-chance levels to approximately 75%. Before and after training, AEPs were recorded to stimuli presented passively with a more medial sound lateralization outnumbering a more lateral one (7:1). In experiment 1, the same lateralizations were used for training and AEP sessions. Significant AEP modulations to the different lateralizations were evident only after training, indicative of a learning-induced mismatch negativity (MMN). More precisely, this MMN at 195-250 ms after stimulus onset followed from differences in the AEP topography to each stimulus position, indicative of changes in the underlying brain network. In experiment 2, mirror-symmetric locations were used for training and AEP sessions; no training-related AEP modulations or MMN were observed. In experiment 3, the discrimination of trained plus equidistant untrained separations was tested psychophysically before and 0, 6, 24, and 48 h after training. Learning-induced plasticity lasted <6 h, did not generalize to untrained lateralizations, and was not the simple result of strengthening the representation of the trained lateralizations. Thus, learning-induced plasticity of auditory spatial discrimination relies on spatial comparisons, rather than a spatial anchor or a general comparator. Furthermore, cortical auditory representations of space are dynamic and subject to rapid reorganization. PMID:17507569

  12. Sensory gain control (amplification) as a mechanism of selective attention: electrophysiological and neuroimaging evidence.

    PubMed Central

    Hillyard, S A; Vogel, E K; Luck, S J

    1998-01-01

    Both physiological and behavioral studies have suggested that stimulus-driven neural activity in the sensory pathways can be modulated in amplitude during selective attention. Recordings of event-related brain potentials indicate that such sensory gain control or amplification processes play an important role in visual-spatial attention. Combined event-related brain potential and neuroimaging experiments provide strong evidence that attentional gain control operates at an early stage of visual processing in extrastriate cortical areas. These data support early selection theories of attention and provide a basis for distinguishing between separate mechanisms of attentional suppression (of unattended inputs) and attentional facilitation (of attended inputs). PMID:9770220

  13. Executive Control of Language in the Bilingual Brain: Integrating the Evidence from Neuroimaging to Neuropsychology

    PubMed Central

    Hervais-Adelman, Alexis Georges; Moser-Mercer, Barbara; Golestani, Narly

    2011-01-01

    In this review we will focus on delineating the neural substrates of the executive control of language in the bilingual brain, based on the existing neuroimaging, intracranial, transcranial magnetic stimulation, and neuropsychological evidence. We will also offer insights from ongoing brain-imaging studies into the development of expertise in multilingual language control. We will concentrate specifically on evidence regarding how the brain selects and controls languages for comprehension and production. This question has been addressed in a number of ways and using various tasks, including language switching during production or perception, translation, and interpretation. We will attempt to synthesize existing evidence in order to bring to light the neural substrates that are crucial to executive control of language. PMID:21954391

  14. Language and thought are not the same thing: evidence from neuroimaging and neurological patients.

    PubMed

    Fedorenko, Evelina; Varley, Rosemary

    2016-04-01

    Is thought possible without language? Individuals with global aphasia, who have almost no ability to understand or produce language, provide a powerful opportunity to find out. Surprisingly, despite their near-total loss of language, these individuals are nonetheless able to add and subtract, solve logic problems, think about another person's thoughts, appreciate music, and successfully navigate their environments. Further, neuroimaging studies show that healthy adults strongly engage the brain's language areas when they understand a sentence, but not when they perform other nonlinguistic tasks such as arithmetic, storing information in working memory, inhibiting prepotent responses, or listening to music. Together, these two complementary lines of evidence provide a clear answer: many aspects of thought engage distinct brain regions from, and do not depend on, language. PMID:27096882

  15. Clocking the social mind by identifying mental processes in the IAT with electrical neuroimaging.

    PubMed

    Schiller, Bastian; Gianotti, Lorena R R; Baumgartner, Thomas; Nash, Kyle; Koenig, Thomas; Knoch, Daria

    2016-03-01

    Why do people take longer to associate the word "love" with outgroup words (incongruent condition) than with ingroup words (congruent condition)? Despite the widespread use of the implicit association test (IAT), it has remained unclear whether this IAT effect is due to additional mental processes in the incongruent condition, or due to longer duration of the same processes. Here, we addressed this previously insoluble issue by assessing the spatiotemporal evolution of brain electrical activity in 83 participants. From stimulus presentation until response production, we identified seven processes. Crucially, all seven processes occurred in the same temporal sequence in both conditions, but participants needed more time to perform one early occurring process (perceptual processing) and one late occurring process (implementing cognitive control to select the motor response) in the incongruent compared with the congruent condition. We also found that the latter process contributed to individual differences in implicit bias. These results advance understanding of the neural mechanics of response time differences in the IAT: They speak against theories that explain the IAT effect as due to additional processes in the incongruent condition and speak in favor of theories that assume a longer duration of specific processes in the incongruent condition. More broadly, our data analysis approach illustrates the potential of electrical neuroimaging to illuminate the temporal organization of mental processes involved in social cognition. PMID:26903643

  16. MEDIAL TEMPORAL LOBE CONTRIBUTIONS TO FUTURE THINKING: EVIDENCE FROM NEUROIMAGING AND AMNESIA

    PubMed Central

    Verfaellie, Mieke; Race, Elizabeth; Keane, Margaret M.

    2013-01-01

    Following early amnesic case reports, there is now considerable evidence suggesting a link between remembering the past and envisioning the future. This link is evident in the overlap in neural substrates as well as cognitive processes involved in both kinds of tasks. While constructing a future narrative requires multiple processes, neuroimaging and lesion data converge on a critical role for the medial temporal lobes (MTL) in retrieving and recombining details from memory in the service of novel simulations. Deficient detail retrieval and recombination may lead to impairments not only in episodic, but also in semantic prospection. MTL contributions to scene construction and mental time travel may further compound impairments in amnesia on tasks that pose additional demands on these processes, but are unlikely to form the core deficit underlying amnesics’ cross-domain future thinking impairment. Future studies exploring the role of episodic memory in other forms of self-projection or future-oriented behaviour may elucidate further the adaptive role of memory. PMID:23447709

  17. Neurogenetic and Neuroimaging Evidence for a Conceptual Model of Dopaminergic Contributions to Obesity

    PubMed Central

    Stanfill, Ansley Grimes; Conley, Yvette; Cashion, Ann; Thompson, Carol; Homayouni, Ramin; Cowan, Patricia; Hathaway, Donna

    2015-01-01

    As the incidence of obesity continues to rise, clinicians and researchers alike are seeking explanations for why some people become obese while others do not. While caloric intake and physical activity most certainly play a role, some individuals continue to gain weight despite careful attention to these factors. Increasing evidence suggests that genetics may play a role, with one potential explanation being genetic variability in genes within the neurotransmitter dopamine pathway. This variability can lead to a disordered experience with the rewarding properties of food. This review of literature examines the extant knowledge about the relationship between obesity and the dopaminergic reward pathways in the brain, with particularly strong evidence provided from neuroimaging and neurogenetic data. Pubmed, Google Scholar, and Cumulative Index to Nursing and Allied Health Literature searches were conducted with the search terms dopamine, obesity, weight gain, food addiction, brain regions relevant to the mesocortical and mesolimbic (reward) pathways, and relevant dopaminergic genes and receptors. These terms returned over 200 articles. Other than a few sentinel articles, articles were published between 1993 and 2013. These data suggest a conceptual model for obesity that emphasizes dopaminergic genetic contributions as well as more traditional risk factors for obesity, such as demographics (age, race, and gender), physical activity, diet, and medications. A greater understanding of variables contributing to weight gain and obesity is imperative for effective clinical treatment. PMID:25576324

  18. Neurogenetic and Neuroimaging Evidence for a Conceptual Model of Dopaminergic Contributions to Obesity.

    PubMed

    Stanfill, Ansley Grimes; Conley, Yvette; Cashion, Ann; Thompson, Carol; Homayouni, Ramin; Cowan, Patricia; Hathaway, Donna

    2015-07-01

    As the incidence of obesity continues to rise, clinicians and researchers alike are seeking explanations for why some people become obese while others do not. While caloric intake and physical activity most certainly play a role, some individuals continue to gain weight despite careful attention to these factors. Increasing evidence suggests that genetics may play a role, with one potential explanation being genetic variability in genes within the neurotransmitter dopamine pathway. This variability can lead to a disordered experience with the rewarding properties of food. This review of literature examines the extant knowledge about the relationship between obesity and the dopaminergic reward pathways in the brain, with particularly strong evidence provided from neuroimaging and neurogenetic data. Pubmed, Google Scholar, and Cumulative Index to Nursing and Allied Health Literature searches were conducted with the search terms dopamine, obesity, weight gain, food addiction, brain regions relevant to the mesocortical and mesolimbic (reward) pathways, and relevant dopaminergic genes and receptors. These terms returned over 200 articles. Other than a few sentinel articles, articles were published between 1993 and 2013. These data suggest a conceptual model for obesity that emphasizes dopaminergic genetic contributions as well as more traditional risk factors for obesity, such as demographics (age, race, and gender), physical activity, diet, and medications. A greater understanding of variables contributing to weight gain and obesity is imperative for effective clinical treatment. PMID:25576324

  19. Effects of Sex Chromosome Aneuploidies on Brain Development: Evidence From Neuroimaging Studies

    PubMed Central

    Lenroot, Rhoshel K.; Lee, Nancy Raitano; Giedd, Jay N.

    2010-01-01

    Variation in the number of sex chromosomes is a relatively common genetic condition, affecting as many as 1/400 individuals. The sex chromosome aneuploidies (SCAs) are associated with characteristic behavioral and cognitive phenotypes, although the degree to which specific individuals are affected can fall within a wide range. Understanding the effects of different dosages of sex chromosome genes on brain development may help to understand the basis for functional differences in affected individuals. It may also be informative regarding how sex chromosomes contribute to typical sexual differentiation. Studies of 47,XXY males make up the bulk of the current literature of neuroimaging studies in individuals with supernumerary sex chromosomes, with a few small studies or case reports of the other SCAs. Findings in 47,XXY males typically include decreased gray and white matter volumes, with most pronounced effects in the frontal and temporal lobes. Functional studies have shown evidence of decreased lateralization. Although the hypogonadism typically found in 47,XXY males may contribute to the decreased brain volume, the observation that 47,XXX females also show decreased brain volume in the presence of normal pubertal maturation suggests a possible direct dosage effect of X chromosome genes. Additional X chromosomes, such as in 49,XXXXY males, are associated with more markedly decreased brain volume and increased incidence of white matter hyperintensities. The limited data regarding effects of having two Y chromosomes (47,XYY) do not find significant differences in brain volume, although there are some reports of increased head size. PMID:20014372

  20. Effects of sex chromosome aneuploidies on brain development: evidence from neuroimaging studies.

    PubMed

    Lenroot, Rhoshel K; Lee, Nancy Raitano; Giedd, Jay N

    2009-01-01

    Variation in the number of sex chromosomes is a relatively common genetic condition, affecting as many as 1/400 individuals. The sex chromosome aneuploidies (SCAs) are associated with characteristic behavioral and cognitive phenotypes, although the degree to which specific individuals are affected can fall within a wide range. Understanding the effects of different dosages of sex chromosome genes on brain development may help to understand the basis for functional differences in affected individuals. It may also be informative regarding how sex chromosomes contribute to typical sexual differentiation. Studies of 47,XXY males make up the bulk of the current literature of neuroimaging studies in individuals with supernumerary sex chromosomes, with a few small studies or case reports of the other SCAs. Findings in 47,XXY males typically include decreased gray and white matter volumes, with most pronounced effects in the frontal and temporal lobes. Functional studies have shown evidence of decreased lateralization. Although the hypogonadism typically found in 47,XXY males may contribute to the decreased brain volume, the observation that 47,XXX females also show decreased brain volume in the presence of normal pubertal maturation suggests a possible direct dosage effect of X chromosome genes. Additional X chromosomes, such as in 49,XXXXY males, are associated with more markedly decreased brain volume and increased incidence of white matter hyperintensities. The limited data regarding effects of having two Y chromosomes (47,XYY) do not find significant differences in brain volume, although there are some reports of increased head size. PMID:20014372

  1. Dreaming as mind wandering: evidence from functional neuroimaging and first-person content reports

    PubMed Central

    Fox, Kieran C. R.; Nijeboer, Savannah; Solomonova, Elizaveta; Domhoff, G. William; Christoff, Kalina

    2013-01-01

    Isolated reports have long suggested a similarity in content and thought processes across mind wandering (MW) during waking, and dream mentation during sleep. This overlap has encouraged speculation that both “daydreaming” and dreaming may engage similar brain mechanisms. To explore this possibility, we systematically examined published first-person experiential reports of MW and dreaming and found many similarities: in both states, content is largely audiovisual and emotional, follows loose narratives tinged with fantasy, is strongly related to current concerns, draws on long-term memory, and simulates social interactions. Both states are also characterized by a relative lack of meta-awareness. To relate first-person reports to neural evidence, we compared meta-analytic data from numerous functional neuroimaging (PET, fMRI) studies of the default mode network (DMN, with high chances of MW) and rapid eye movement (REM) sleep (with high chances of dreaming). Our findings show large overlaps in activation patterns of cortical regions: similar to MW/DMN activity, dreaming and REM sleep activate regions implicated in self-referential thought and memory, including medial prefrontal cortex (PFC), medial temporal lobe structures, and posterior cingulate. Conversely, in REM sleep numerous PFC executive regions are deactivated, even beyond levels seen during waking MW. We argue that dreaming can be understood as an “intensified” version of waking MW: though the two share many similarities, dreams tend to be longer, more visual and immersive, and to more strongly recruit numerous key hubs of the DMN. Further, whereas MW recruits fewer PFC regions than goal-directed thought, dreaming appears to be characterized by an even deeper quiescence of PFC regions involved in cognitive control and metacognition, with a corresponding lack of insight and meta-awareness. We suggest, then, that dreaming amplifies the same features that distinguish MW from goal-directed waking

  2. Effect of mind on brain activity: evidence from neuroimaging studies of psychotherapy and placebo effect.

    PubMed

    Beauregard, Mario

    2009-01-01

    Mentalistic variables must be considered to reach a correct understanding of the neurophysiological basis of behavior in humans. Confusion regarding the relative importance of neurophysiological and mentalistic variables can lead to important misconceptions about causes and effects in the study of human behavior. In this article, we review neuroimaging studies of the effect of psychotherapy in patients suffering from diverse forms of psychopathology (obsessive-compulsive disorder, panic disorder, unipolar major depressive disorder, spider phobia). We also review neuroimaging studies of the placebo effect in healthy individuals (placebo analgesia, psychostimulant expectation) and patients with Parkinson's disease or unipolar major depressive disorder. Mental functions and processes involved in diverse forms of psychotherapy exert a significant influence on brain activity. With regard to the placebo effect, beliefs and expectations can markedly modulate neurophysiological and neurochemical activity in brain regions involved in perception, movement, pain and various aspects of emotion processing. The findings of the neuroimaging studies reviewed here strongly support the view that the subjective nature and the intentional content of mental processes significantly influence the various levels of brain functioning (e.g. molecular, cellular, neural circuit) and brain plasticity. PMID:19023697

  3. Clinical neuroimaging

    SciTech Connect

    Theodore, W.H.

    1988-01-01

    This book contains chapters on neuroimaging. Included are the following chapters: diagnostic neuroimaging in stroke, position emission tomography in cerebrovascular disease: clinical applications, and neuroradiologic work-up of brain tumors.

  4. The cognitive and neural time course of empathy and sympathy: an electrical neuroimaging study on self-other interaction.

    PubMed

    Thirioux, B; Mercier, M R; Blanke, O; Berthoz, A

    2014-05-16

    Although extensively investigated in socio-cognitive neuroscience, empathy is difficult to study. The first difficulty originates in its multifaceted nature. According to the multidimensional model, empathy combines emotional, automatic (simulation), cognitive (mentalizing) and regulatory (executive functions) processes. Substantial functional magnetic resonance imaging (fMRI) data demonstrated that co-activations in the mirror neuron system (MNS) and mentalizing network (MENT) sustain this co-recruitment of so-called first- and second-person-like processes. Because of the poor temporal resolution of fMRI techniques, we currently lack evidence about the precise timing of the MNS-MENT combination. An important challenge is, thus, to disentangle how MNS and MENT dynamically work together along time in empathy. Moreover, the role of the executive functions in the MNS-MENT combination time course is still unknown. Second, empathy - feeling into - is closely related to sympathy - feeling with - and both phenomena are often conflated in experimental studies on intersubjectivity. In this electrical neuroimaging (EEG) pilot-study, we tested whether the egocentered vs. heterocentered visuo-spatial mechanisms respectively associated with sympathy and empathy differentially modulate the dynamic combination of the MNS-MENT activations in their respective neural time course. For that, we employed our newly developed behavioral paradigm assessing the visuo-spatial - but not emotional - features of empathy and sympathy. Using a data-driven approach, we report that empathy and sympathy are underlied by sequential activations in the MNS from the insula to the inferior frontal gyrus (IFG) between 63ms and 424ms. However, at 333-424ms, empathy triggered greater co-activations in the right IFG and dorsolateral prefrontal cortex (dlPFC) (executive functions). Linking together our present and prior (Thirioux et al., 2010) findings from the same dataset, we suggest that this greater

  5. Neuroimaging and treatment evidence for clinical staging in psychotic disorders: from the at-risk mental state to chronic schizophrenia.

    PubMed

    Wood, Stephen J; Yung, Alison R; McGorry, Patrick D; Pantelis, Christos

    2011-10-01

    A new approach to understanding severe mental disorders such as schizophrenia is to adopt a clinical staging model. Such a model defines the extent of the illness such that earlier and milder phenomena are distinguished from later, more impairing features. Specifically, a clinical staging model makes three key predictions. First, pathologic measures should be more abnormal in more severe stages. Second, patients who progress between the stages should show change in these same pathologic measures. Finally, treatment should be more effective in the earlier stages, as well as more benign. In this article, we review the evidence for these three predictions from studies of psychotic disorders, with a focus on neuroimaging data. For all three, the balance of evidence supports the predictions of the staging model. However, there are a number of alternative explanations for these findings, including the effects of medication and symptom heterogeneity. PMID:21762875

  6. Overlapping neurobehavioral circuits in ADHD, obesity, and binge eating: evidence from neuroimaging research.

    PubMed

    Seymour, Karen E; Reinblatt, Shauna P; Benson, Leora; Carnell, Susan

    2015-08-01

    Attention-deficit/hyperactivity disorder (ADHD) and conditions involving excessive eating (eg, obesity, binge/loss of control eating) are increasingly prevalent within pediatric populations, and correlational and some longitudinal studies have suggested inter-relationships between these disorders. In addition, a number of common neural correlates are emerging across conditions, eg, functional abnormalities within circuits subserving reward processing and executive functioning. To explore this potential cross-condition overlap in neurobehavioral underpinnings, we selectively review relevant functional neuroimaging literature, specifically focusing on studies probing (i) reward processing, (ii) response inhibition, and (iii) emotional processing and regulation, and we outline 3 specific shared neurobehavioral circuits. Based on our review, we also identify gaps within the literature that would benefit from further research. PMID:26098969

  7. Three key regions for supervisory attentional control: Evidence from neuroimaging meta-analyses

    PubMed Central

    Cieslik, Edna C.; Mueller, Veronika I.; Eickhoff, Claudia R.; Langner, Robert; Eickhoff, Simon B.

    2014-01-01

    The supervisory attentional system has been proposed to mediate non-routine, goal-oriented behaviour by guiding the selection and maintenance of the goal-relevant task schema. Here, we aimed to delineate the brain regions that mediate these high-level control processes via neuroimaging meta-analysis. In particular, we investigated the core neural correlates of a wide range of tasks requiring supervisory control for the suppression of a routine action in favour of another, non-routine one. Our sample comprised n = 173 experiments employing go/no-go, stop-signal, Stroop or spatial interference tasks. Consistent convergence across all four paradigm classes was restricted to right anterior insula and inferior frontal junction, with anterior midcingulate cortex and pre-supplementary motor area being consistently involved in all but the go/no-go task. Taken together with lesion studies in patients, our findings suggest that the controlled activation and maintenance of adequate task schemata relies, across paradigms, on a right-dominant midcingulo-insular-inferior frontal core network. This also implies that the role of other prefrontal and parietal regions may be less domain-general than previously thought. PMID:25446951

  8. Sensing, assessing, and augmenting threat detection: behavioral, neuroimaging, and brain stimulation evidence for the critical role of attention

    PubMed Central

    Parasuraman, Raja; Galster, Scott

    2013-01-01

    Rapidly identifying the potentially threatening movements of other people and objects—biological motion perception and action understanding—is critical to maintaining security in many civilian and military settings. A key approach to improving threat detection in these environments is to sense when less than ideal conditions exist for the human observer, assess that condition relative to an expected standard, and if necessary use tools to augment human performance. Action perception is typically viewed as a relatively “primitive,” automatic function immune to top-down effects. However, recent research shows that attention is a top-down factor that has a critical influence on the identification of threat-related targets. In this paper we show that detection of motion-based threats is attention sensitive when surveillance images are obscured by other movements, when they are visually degraded, when other stimuli or tasks compete for attention, or when low-probability threats must be watched for over long periods of time—all features typical of operational security settings. Neuroimaging studies reveal that action understanding recruits a distributed network of brain regions, including the superior temporal cortex, intraparietal cortex, and inferior frontal cortex. Within this network, attention modulates activation of the superior temporal sulcus (STS) and middle temporal gyrus. The dorsal frontoparietal network may provide the source of attention-modulation signals to action representation areas. Stimulation of this attention network should therefore enhance threat detection. We show that transcranial Direct Current Stimulation (tDCS) at 2 mA accelerates perceptual learning of participants performing a challenging threat-detection task. Together, cognitive, neuroimaging, and brain stimulation studies provide converging evidence for the critical role of attention in the detection and understanding of threat-related intentional actions. PMID:23781194

  9. Evidence against functionalism from neuroimaging of the alien colour effect in synaesthesia.

    PubMed

    Gray, Jeffrey A; Parslow, David M; Brammer, Michael J; Chopping, Susan; Vythelingum, Goparlen N; ffytche, Dominic H

    2006-02-01

    Coloured hearing synaesthetes experience colours to heard words, as confirmed by reliability of self-report, psychophysical testing and functional neuroimaging data. Some also describe the 'alien colour effect' (ACE): in response to colour names, they experience colours different from those named. We have previously reported that the ACE slows colour naming in a Stroop task, reflecting cognitive interference from synaesthetically induced colours, which depends upon their being consciously experienced. It has been proposed that the hippocampus mediates such consciously experienced conflict. Consistent with this hypothesis, we now report that, in functional magnetic resonance imaging of the Stroop task, hippocampal activation differentiates synaesthetes with the ACE from those without it and from non-synaesthete controls. These findings confirm the reality of coloured hearing synaesthesia and the ACE, phenomena which pose major challenges to the dominant contemporary account of mental states, functionalism. Reductive functionalism identifies types of mental states with causal roles: relations to inputs, outputs and other states. However, conscious mental states, such as experiences of colour, are distinguished by their qualitative properties or qualia. If functionalism is applied to conscious mental states, it identifies the qualitative type of an experience with its causal role or function. This entails both that experiences with disparate qualitative properties cannot have the same functional properties, and that experiences with disparate functional properties cannot have the same qualitative properties. Challenges to functionalism have often denied the first entailment. Here, we challenge the second entailment on empirical grounds. In coloured hearing synaesthesia, colour qualia are associated with both hearing words and seeing surfaces; and, in the ACE, these two functions act in opposition to one another. Whatever its merits as an account of other mental states

  10. The Semantic Variant of Primary Progressive Aphasia: Clinical and Neuroimaging Evidence in Single Subjects

    PubMed Central

    Iaccarino, Leonardo; Crespi, Chiara; Della Rosa, Pasquale Anthony; Catricalà, Eleonora; Guidi, Lucia; Marcone, Alessandra; Tagliavini, Fabrizio; Magnani, Giuseppe; Cappa, Stefano F.; Perani, Daniela

    2015-01-01

    Background/Aim We present a clinical-neuroimaging study in a series of patients with a clinical diagnosis of semantic variant of primary progressive aphasia (svPPA), with the aim to provide clinical-functional correlations of the cognitive and behavioral manifestations at the single-subject level. Methods We performed neuropsychological investigations, 18F-FDG-PET single-subject and group analysis, with an optimized SPM voxel-based approach, and correlation analyses. A measurement of white matter integrity by means of diffusion tensor imaging (DTI) was also available for a subgroup of patients. Results Cognitive assessment confirmed the presence of typical semantic memory deficits in all patients, with a relative sparing of executive, attentional, visuo-constructional, and episodic memory domains. 18F-FDG-PET showed a consistent pattern of cerebral hypometabolism across all patients, which correlated with performance in semantic memory tasks. In addition, a majority of patients also presented with behavioral disturbances associated with metabolic dysfunction in limbic structures. In a subgroup of cases the DTI analysis showed FA abnormalities in the inferior longitudinal and uncinate fasciculi. Discussion Each svPPA individual had functional derangement involving an extended, connected system within the left temporal lobe, a crucial part of the verbal semantic network, as well as an involvement of limbic structures. The latter was associated with behavioral manifestations and extended beyond the area of atrophy shown by CT scan. Conclusion Single-subject 18F-FDG-PET analysis can account for both cognitive and behavioral alterations in svPPA. This provides useful support to the clinical diagnosis. PMID:25756991

  11. Dynamic spatiotemporal brain analyses using high-performance electrical neuroimaging, Part II: A step-by-step tutorial.

    PubMed

    Cacioppo, Stephanie; Cacioppo, John T

    2015-12-30

    Our recently published analytic toolbox (Cacioppo et al., 2014), running under MATLAB environment and Brainstorm, offered a theoretical framework and set of validation studies for the automatic detection of event-related changes in the global pattern and global field power of electrical brain activity. Here, we provide a step-by-step tutorial of this toolbox along with a detailed description of analytical plans (aka the Chicago Electrical Neuroimaging Analytics, CENA) for the statistical analysis of brain microstate configuration and global field power in within and between-subject designs. Available CENA functions include: (1) a difference wave function; (2) a high-performance microsegmentation suite (HPMS), which consists of three specific analytic tools: (i) a root mean square error (RMSE) metric for identifying stable states and transition states across discrete event-related brain microstates; (ii) a similarity metric based on cosine distance in n dimensional sensor space to determine whether template maps for successive brain microstates differ in configuration of brain activity, and (iii) global field power (GFP) metrics for identifying changes in the overall level of activation of the brain; (3) a bootstrapping function for assessing the extent to which the solutions identified in the HPMS are robust (reliable, generalizable) and for empirically deriving additional experimental hypotheses; and (4) step-by-step procedures for performing a priori contrasts for data analysis. CENA is freely available for brain data spatiotemporal analyses at https://hpenlaboratory.uchicago.edu/page/cena, with sample data, user tutorial videos, and documentation. PMID:26363189

  12. Differential Diagnosis of Dysgraphia, Dyslexia, and OWL LD: Behavioral and Neuroimaging Evidence

    ERIC Educational Resources Information Center

    Berninger, Virginia W.; Richards, Todd L.; Abbott, Robert D.

    2015-01-01

    In Study 1, children in grades 4-9 (N = 88, 29 females and 59 males) with persisting reading and/or writing disabilities, despite considerable prior specialized instruction in and out of school, were given an evidence-based comprehensive assessment battery at the university while parents completed questionnaires regarding past and current history…

  13. Towards Validation of a New Computerised Test of Goal Neglect: Preliminary Evidence from Clinical and Neuroimaging Pilot Studies

    PubMed Central

    Cullen, Breda; Brennan, David; Manly, Tom; Evans, Jonathan J.

    2016-01-01

    Objective Goal neglect is a significant problem following brain injury, and is a target for rehabilitation. It is not yet known how neural activation might change to reflect rehabilitation gains. We developed a computerised multiple elements test (CMET), suitable for use in neuroimaging paradigms. Design Pilot correlational study and event-related fMRI study. Methods In Study 1, 18 adults with acquired brain injury were assessed using the CMET, other tests of goal neglect (Hotel Test; Modified Six Elements Test) and tests of reasoning. In Study 2, 12 healthy adults underwent fMRI, during which the CMET was administered under two conditions: self-generated switching and experimenter-prompted switching. Results Among the clinical sample, CMET performance was positively correlated with both the Hotel Test (r = 0.675, p = 0.003) and the Modified Six Elements Test (r = 0.568, p = 0.014), but not with other clinical or demographic measures. In the healthy sample, fMRI demonstrated significant activation in rostro-lateral prefrontal cortex in the self-generated condition compared with the prompted condition (peak 40, 44, 4; ZE = 4.25, p(FWEcorr) = 0.026). Conclusions These pilot studies provide preliminary evidence towards the validation of the CMET as a measure of goal neglect. Future studies will aim to further establish its psychometric properties, and determine optimum pre- and post-rehabilitation fMRI paradigms. PMID:26824704

  14. Through a scanner darkly: functional neuroimaging as evidence of a criminal defendant's past mental states.

    PubMed

    Brown, Teneille; Murphy, Emily

    2010-04-01

    As with phrenology and the polygraph, society is again confronted with a device that the media claims is capable of reading our minds. Functional magnetic resonance imaging ("fMRI"), along with other types of functional brain imaging technologies, is currently being introduced at various stages of a criminal trial as evidence of a defendant's past mental state. This Article demonstrates that functional brain images should not currently be admitted as evidence into courts for this purpose. Using the analytical framework provided by Federal Rule of Evidence 403 as a threshold to a Daubert/Frye analysis, we demonstrate that, when fMRI methodology is properly understood, brain images are only minimally probative of a defendant's past mental states and are almost certainly more unfairly prejudicial than probative on balance. Careful and detailed explanation of the underlying science separates this Article from others, which have tended to paint fMRI with a gloss of credibility and certainty for all courtroom-relevant applications. Instead, we argue that this technology may present a particularly strong form of unfair prejudice in addition to its potential to mislead jurors and waste the court's resources. Finally, since fMRI methodology may one day improve such that its probative value is no longer eclipsed by its extreme potential for unfair prejudice, we offer a nonexhaustive checklist that judges and counsel can use to authenticate functional brain images and assess the weight these images are to be accorded by fact finders. PMID:20429137

  15. Imaging evidence and recommendations for traumatic brain injury: conventional neuroimaging techniques.

    PubMed

    Wintermark, Max; Sanelli, Pina C; Anzai, Yoshimi; Tsiouris, A John; Whitlow, Christopher T

    2015-02-01

    Imaging plays an essential role in identifying intracranial injury in patients with traumatic brain injury (TBI). The goals of imaging include (1) detecting injuries that may require immediate surgical or procedural intervention, (2) detecting injuries that may benefit from early medical therapy or vigilant neurologic supervision, and (3) determining the prognosis of patients to tailor rehabilitative therapy or help with family counseling and discharge planning. In this article, the authors perform a review of the evidence on the utility of various imaging techniques in patients presenting with TBI to provide guidance for evidence-based, clinical imaging protocols. The intent of this article is to suggest practical imaging recommendations for patients presenting with TBI across different practice settings and to simultaneously provide the rationale and background evidence supporting their use. These recommendations should ultimately assist referring physicians faced with the task of ordering appropriate imaging tests in particular patients with TBI for whom they are providing care. These recommendations should also help radiologists advise their clinical colleagues on appropriate imaging utilization for patients with TBI. PMID:25456317

  16. Immunity factor contributes to altered brain functional networks in individuals at risk for Alzheimer's disease: Neuroimaging-genetic evidence.

    PubMed

    Bai, Feng; Shi, Yongmei; Yuan, Yonggui; Xie, Chunming; Zhang, Zhijun

    2016-08-01

    Clusterin (CLU) is recognized as a secreted protein that is related to the processes of inflammation and immunity in the pathogenesis of Alzheimer's disease (AD). The effects of the risk variant of the C allele at the rs11136000 locus of the CLU gene are associated with variations in the brain structure and function. However, the relationship of the CLU-C allele to architectural disruptions in resting-state networks in amnestic mild cognitive impairment (aMCI) subjects (i.e., individuals with elevated risk of AD) remains relatively unknown. Using resting-state functional magnetic resonance imaging and an imaging genetic approach, this study investigated whether individual brain functional networks, i.e., the default mode network (DMN) and the task-positive network, were modulated by the CLU-C allele (rs11136000) in 50 elderly participants, including 26 aMCI subjects and 24 healthy controls. CLU-by-aMCI interactions were associated with the information-bridging regions between resting-state networks rather than with the DMN itself, especially in cortical midline regions. Interestingly, the complex communications between resting-state networks were enhanced in aMCI subjects with the CLU rs11136000 CC genotype and were modulated by the degree of memory impairment, suggesting a reconstructed balance of the resting-state networks in these individuals with an elevated risk of AD. The neuroimaging-genetic evidence indicates that immunity factors may contribute to alterations in brain functional networks in aMCI. These findings add to the evidence that the CLU gene may represent a potential therapeutic target for slowing disease progression in AD. PMID:26899953

  17. Evolving Evidence for the Value of Neuroimaging Methods and Biological Markers in Subjects Categorized with Subjective Cognitive Decline.

    PubMed

    Lista, Simone; Molinuevo, Jose L; Cavedo, Enrica; Rami, Lorena; Amouyel, Philippe; Teipel, Stefan J; Garaci, Francesco; Toschi, Nicola; Habert, Marie-Odile; Blennow, Kaj; Zetterberg, Henrik; O'Bryant, Sid E; Johnson, Leigh; Galluzzi, Samantha; Bokde, Arun L W; Broich, Karl; Herholz, Karl; Bakardjian, Hovagim; Dubois, Bruno; Jessen, Frank; Carrillo, Maria C; Aisen, Paul S; Hampel, Harald

    2015-09-24

    There is evolving evidence that individuals categorized with subjective cognitive decline (SCD) are potentially at higher risk for developing objective and progressive cognitive impairment compared to cognitively healthy individuals without apparent subjective complaints. Interestingly, SCD, during advancing preclinical Alzheimer's disease (AD), may denote very early, subtle cognitive decline that cannot be identified using established standardized tests of cognitive performance. The substantial heterogeneity of existing SCD-related research data has led the Subjective Cognitive Decline Initiative (SCD-I) to accomplish an international consensus on the definition of a conceptual research framework on SCD in preclinical AD. In the area of biological markers, the cerebrospinal fluid signature of AD has been reported to be more prevalent in subjects with SCD compared to healthy controls; moreover, there is a pronounced atrophy, as demonstrated by magnetic resonance imaging, and an increased hypometabolism, as revealed by positron emission tomography, in characteristic brain regions affected by AD. In addition, SCD individuals carrying an apolipoprotein ɛ4 allele are more likely to display AD-phenotypic alterations. The urgent requirement to detect and diagnose AD as early as possible has led to the critical examination of the diagnostic power of biological markers, neurophysiology, and neuroimaging methods for AD-related risk and clinical progression in individuals defined with SCD. Observational studies on the predictive value of SCD for developing AD may potentially be of practical value, and an evidence-based, validated, qualified, and fully operationalized concept may inform clinical diagnostic practice and guide earlier designs in future therapy trials. PMID:26402088

  18. Motor Inhibition during Overt and Covert Actions: An Electrical Neuroimaging Study

    PubMed Central

    Angelini, Monica; Calbi, Marta; Ferrari, Annachiara; Sbriscia-Fioretti, Beatrice; Franca, Michele; Gallese, Vittorio; Umiltà, Maria Alessandra

    2015-01-01

    Given ample evidence for shared cortical structures involved in encoding actions, whether or not subsequently executed, a still unsolved problem is the identification of neural mechanisms of motor inhibition, preventing “covert actions” as motor imagery from being performed, in spite of the activation of the motor system. The principal aims of the present study were the evaluation of: 1) the presence in covert actions as motor imagery of putative motor inhibitory mechanisms; 2) their underlying cerebral sources; 3) their differences or similarities with respect to cerebral networks underpinning the inhibition of overt actions during a Go/NoGo task. For these purposes, we performed a high density EEG study evaluating the cerebral microstates and their related sources elicited during two types of Go/NoGo tasks, requiring the execution or withholding of an overt or a covert imagined action, respectively. Our results show for the first time the engagement during motor imagery of key nodes of a putative inhibitory network (including pre-supplementary motor area and right inferior frontal gyrus) partially overlapping with those activated for the inhibition of an overt action during the overt NoGo condition. At the same time, different patterns of temporal recruitment in these shared neural inhibitory substrates are shown, in accord with the intended overt or covert modality of action performance. The evidence that apparently divergent mechanisms such as controlled inhibition of overt actions and contingent automatic inhibition of covert actions do indeed share partially overlapping neural substrates, further challenges the rigid dichotomy between conscious, explicit, flexible and unconscious, implicit, inflexible forms of motor behavioral control. PMID:26000451

  19. Neuroimaging Evidence for 2 Types of Plasticity in Association with Visual Perceptual Learning.

    PubMed

    Shibata, Kazuhisa; Sasaki, Yuka; Kawato, Mitsuo; Watanabe, Takeo

    2016-09-01

    Visual perceptual learning (VPL) is long-term performance improvement as a result of perceptual experience. It is unclear whether VPL is associated with refinement in representations of the trained feature (feature-based plasticity), improvement in processing of the trained task (task-based plasticity), or both. Here, we provide empirical evidence that VPL of motion detection is associated with both types of plasticity which occur predominantly in different brain areas. Before and after training on a motion detection task, subjects' neural responses to the trained motion stimuli were measured using functional magnetic resonance imaging. In V3A, significant response changes after training were observed specifically to the trained motion stimulus but independently of whether subjects performed the trained task. This suggests that the response changes in V3A represent feature-based plasticity in VPL of motion detection. In V1 and the intraparietal sulcus, significant response changes were found only when subjects performed the trained task on the trained motion stimulus. This suggests that the response changes in these areas reflect task-based plasticity. These results collectively suggest that VPL of motion detection is associated with the 2 types of plasticity, which occur in different areas and therefore have separate mechanisms at least to some degree. PMID:27298301

  20. Neuroimaging Evidence for 2 Types of Plasticity in Association with Visual Perceptual Learning

    PubMed Central

    Shibata, Kazuhisa; Sasaki, Yuka; Kawato, Mitsuo; Watanabe, Takeo

    2016-01-01

    Visual perceptual learning (VPL) is long-term performance improvement as a result of perceptual experience. It is unclear whether VPL is associated with refinement in representations of the trained feature (feature-based plasticity), improvement in processing of the trained task (task-based plasticity), or both. Here, we provide empirical evidence that VPL of motion detection is associated with both types of plasticity which occur predominantly in different brain areas. Before and after training on a motion detection task, subjects' neural responses to the trained motion stimuli were measured using functional magnetic resonance imaging. In V3A, significant response changes after training were observed specifically to the trained motion stimulus but independently of whether subjects performed the trained task. This suggests that the response changes in V3A represent feature-based plasticity in VPL of motion detection. In V1 and the intraparietal sulcus, significant response changes were found only when subjects performed the trained task on the trained motion stimulus. This suggests that the response changes in these areas reflect task-based plasticity. These results collectively suggest that VPL of motion detection is associated with the 2 types of plasticity, which occur in different areas and therefore have separate mechanisms at least to some degree. PMID:27298301

  1. Neuroimaging evidence for top-down maturation of selective auditory attention.

    PubMed

    Herdman, Anthony T

    2011-10-01

    This study investigated maturational differences of selective auditory attention effects on transient evoked responses and 40-Hz auditory steady-state responses between children and adults. Magnetoencephalography (MEG) was recorded from children and adults performing a task where they attended to 40-Hz amplitude-modulated (AM) tones of 1,200 Hz while ignoring 40-Hz AM tones of 800 Hz. By using standard dipole-modeling procedures, the N1m of the transient evoked fields and the 40-Hz ASSRs were localized to secondary and primary auditory cortices, respectively. Source waveforms for the transient evoked fields and ASSRs were reconstructed at these locations and compared between attended and unattended tones. Source waveforms revealed attention enhances the sustained negativity of the transient evoked responses in both adults and children around 250 and 400 ms. ASSRs were also found to be enhanced within this time range but only for adults. The results provide evidence for a limited role of attention modification of the 40-Hz ASSRs in children around the age of 12 years old. Because ASSRs are generated in a lower auditory processing stage as compared to the transient auditory evoked responses, findings from the present study could indicate that the maturation of attention progresses in top-to-bottom manner. These findings fit with the notion that as a person gains sensory experience selective gating of relevant from irrelevant information likely occurs at earlier and earlier processing levels in order to become more automatic and efficient. PMID:21499933

  2. Early neuroimaging diagnosis of Alzheimer's disease

    NASA Astrophysics Data System (ADS)

    Jiao, Jianling; Liu, Timon C.; Li, Yan; Liu, Songhao

    2002-04-01

    Neuroimaging has played an important role in evaluating the Alzheimer's disease (AD) patients, and its uses are growing. Magnetic resonance imaging (MRI) may show the presence of cerebral infarcts and white matter disease. Single photon emission computed tomography (SPECT) and positron emission tomography (PET), which visualize such cerebral functions as glucose metabolism and blood flow, may provide positive evidence to support the diagnosis of AD. Electrical impedance tomography (EIT) is a recently developed technique which enables the internal impedance of an object to be imaged noninvasively.

  3. Neuroimaging evidence of altered fronto-cortical and striatal function after prolonged cocaine self-administration in the rat.

    PubMed

    Gozzi, Alessandro; Tessari, Michela; Dacome, Lisa; Agosta, Federica; Lepore, Stefano; Lanzoni, Anna; Cristofori, Patrizia; Pich, Emilio M; Corsi, Mauro; Bifone, Angelo

    2011-11-01

    Cocaine addiction is often modeled in experimental paradigms where rodents learn to self-administer (SA) the drug. However, the extent to which these models replicate the functional alterations observed in clinical neuroimaging studies of cocaine addiction remains unknown. We used magnetic resonance imaging (MRI) to assess basal and evoked brain function in rats subjected to a prolonged, extended-access cocaine SA scheme. Specifically, we measured basal cerebral blood volume (bCBV), an established correlate of basal metabolism, and assessed the reactivity of the dopaminergic system by mapping the pharmacological MRI (phMRI) response evoked by the dopamine-releaser amphetamine. Cocaine-exposed subjects exhibited reduced bCBV in fronto-cortical areas, nucleus accumbens, ventral hippocampus, and thalamus. The cocaine group also showed an attenuated functional response to amphetamine in ventrostriatal areas, an effect that was significantly correlated with total cocaine intake. An inverse relationship between bCBV in the reticular thalamus and the frontal response elicited by amphetamine was found in control subjects but not in the cocaine group, suggesting that the inhibitory interplay within this attentional circuit may be compromised by the drug. Importantly, histopathological analysis did not reveal significant alterations of the microvascular bed in the brain of cocaine-exposed subjects, suggesting that the imaging findings cannot be merely ascribed to cocaine-induced vascular damage. These results document that chronic, extended-access cocaine SA in the rat produces focal fronto-cortical and striatal alterations that serve as plausible neurobiological substrate for the behavioral expression of compulsive drug intake in laboratory animals. PMID:21775976

  4. Spatio-temporal dynamics of kind versus hostile intentions in the human brain: An electrical neuroimaging study.

    PubMed

    Wang, Yiwen; Huang, Liang; Zhang, Wei; Zhang, Zhen; Cacioppo, Stephanie

    2015-01-01

    Neuroscience research suggests that inferring neutral intentions of other people recruits a specific brain network within the inferior fronto-parietal action observation network as well as a putative social network including brain areas subserving theory of mind, such as the posterior superior temporal sulcus (pSTS), the temporo-parietal junction (TPJ), and also the anterior cingulate cortex (ACC). Recent studies on harmful intentions have refined this network by showing the specific involvement of the ACC, amygdala, and ventromedial prefrontal cortex (vmPFC) in early stages (within 200 ms) of information processing. However, the functional dynamics for kind intentions within and among these networks remains unclear. To address this question, we measured electrical brain activity from 18 healthy adult participants while they were performing an intention inference task with three different types of intentions: kind, hostile and non-interactive. Electrophysiological results revealed that kind intentions were characterized by significantly larger peak amplitudes of N2 over the frontal sites than those for hostile and non-interactive intentions. On the other hand, there were no significant differences between hostile and non-interactive intentions at N2. The source analysis suggested that the vicinity of the left cingulate gyrus contributed to the N2 effect by subtracting the kindness condition from the non-interactive condition within 250-350 ms. At a later stage (i.e., during the 270-500 ms epoch), the peak amplitude of the P3 over the parietal sites and the right hemisphere was significantly larger for hostile intentions compared to the kind and non-interactive intentions. No significant differences were observed at P3 between kind and non-interactive intentions. The source analysis showed that the vicinity of the left anterior cingulate cortex contributed to the P3 effect by subtracting the hostility condition from the non-interactive condition within 450-550 ms

  5. Visual Attention and the Neuroimage Bias

    PubMed Central

    Baker, D. A.; Schweitzer, N. J.; Risko, Evan F.; Ware, Jillian M.

    2013-01-01

    Several highly-cited experiments have presented evidence suggesting that neuroimages may unduly bias laypeople’s judgments of scientific research. This finding has been especially worrisome to the legal community in which neuroimage techniques may be used to produce evidence of a person’s mental state. However, a more recent body of work that has looked directly at the independent impact of neuroimages on layperson decision-making (both in legal and more general arenas), and has failed to find evidence of bias. To help resolve these conflicting findings, this research uses eye tracking technology to provide a measure of attention to different visual representations of neuroscientific data. Finding an effect of neuroimages on the distribution of attention would provide a potential mechanism for the influence of neuroimages on higher-level decisions. In the present experiment, a sample of laypeople viewed a vignette that briefly described a court case in which the defendant’s actions might have been explained by a neurological defect. Accompanying these vignettes was either an MRI image of the defendant’s brain, or a bar graph depicting levels of brain activity–two competing visualizations that have been the focus of much of the previous research on the neuroimage bias. We found that, while laypeople differentially attended to neuroimagery relative to the bar graph, this did not translate into differential judgments in a way that would support the idea of a neuroimage bias. PMID:24040251

  6. Neuromarketing: the hope and hype of neuroimaging in business.

    PubMed

    Ariely, Dan; Berns, Gregory S

    2010-04-01

    The application of neuroimaging methods to product marketing - neuromarketing - has recently gained considerable popularity. We propose that there are two main reasons for this trend. First, the possibility that neuroimaging will become cheaper and faster than other marketing methods; and second, the hope that neuroimaging will provide marketers with information that is not obtainable through conventional marketing methods. Although neuroimaging is unlikely to be cheaper than other tools in the near future, there is growing evidence that it may provide hidden information about the consumer experience. The most promising application of neuroimaging methods to marketing may come before a product is even released - when it is just an idea being developed. PMID:20197790

  7. Where do bright ideas occur in our brain? Meta-analytic evidence from neuroimaging studies of domain-specific creativity.

    PubMed

    Boccia, Maddalena; Piccardi, Laura; Palermo, Liana; Nori, Raffaella; Palmiero, Massimiliano

    2015-01-01

    Many studies have assessed the neural underpinnings of creativity, failing to find a clear anatomical localization. We aimed to provide evidence for a multi-componential neural system for creativity. We applied a general activation likelihood estimation (ALE) meta-analysis to 45 fMRI studies. Three individual ALE analyses were performed to assess creativity in different cognitive domains (Musical, Verbal, and Visuo-spatial). The general ALE revealed that creativity relies on clusters of activations in the bilateral occipital, parietal, frontal, and temporal lobes. The individual ALE revealed different maximal activation in different domains. Musical creativity yields activations in the bilateral medial frontal gyrus, in the left cingulate gyrus, middle frontal gyrus, and inferior parietal lobule and in the right postcentral and fusiform gyri. Verbal creativity yields activations mainly located in the left hemisphere, in the prefrontal cortex, middle and superior temporal gyri, inferior parietal lobule, postcentral and supramarginal gyri, middle occipital gyrus, and insula. The right inferior frontal gyrus and the lingual gyrus were also activated. Visuo-spatial creativity activates the right middle and inferior frontal gyri, the bilateral thalamus and the left precentral gyrus. This evidence suggests that creativity relies on multi-componential neural networks and that different creativity domains depend on different brain regions. PMID:26322002

  8. Where do bright ideas occur in our brain? Meta-analytic evidence from neuroimaging studies of domain-specific creativity

    PubMed Central

    Boccia, Maddalena; Piccardi, Laura; Palermo, Liana; Nori, Raffaella; Palmiero, Massimiliano

    2015-01-01

    Many studies have assessed the neural underpinnings of creativity, failing to find a clear anatomical localization. We aimed to provide evidence for a multi-componential neural system for creativity. We applied a general activation likelihood estimation (ALE) meta-analysis to 45 fMRI studies. Three individual ALE analyses were performed to assess creativity in different cognitive domains (Musical, Verbal, and Visuo-spatial). The general ALE revealed that creativity relies on clusters of activations in the bilateral occipital, parietal, frontal, and temporal lobes. The individual ALE revealed different maximal activation in different domains. Musical creativity yields activations in the bilateral medial frontal gyrus, in the left cingulate gyrus, middle frontal gyrus, and inferior parietal lobule and in the right postcentral and fusiform gyri. Verbal creativity yields activations mainly located in the left hemisphere, in the prefrontal cortex, middle and superior temporal gyri, inferior parietal lobule, postcentral and supramarginal gyri, middle occipital gyrus, and insula. The right inferior frontal gyrus and the lingual gyrus were also activated. Visuo-spatial creativity activates the right middle and inferior frontal gyri, the bilateral thalamus and the left precentral gyrus. This evidence suggests that creativity relies on multi-componential neural networks and that different creativity domains depend on different brain regions. PMID:26322002

  9. Behavioral and multimodal neuroimaging evidence for a deficit in brain timing networks in stuttering: a hypothesis and theory

    PubMed Central

    Etchell, Andrew C.; Johnson, Blake W.; Sowman, Paul F.

    2014-01-01

    The fluent production of speech requires accurately timed movements. In this article, we propose that a deficit in brain timing networks is one of the core neurophysiological deficits in stuttering. We first discuss the experimental evidence supporting the involvement of the basal ganglia and supplementary motor area (SMA) in stuttering and the involvement of the cerebellum as a possible mechanism for compensating for the neural deficits that underlie stuttering. Next, we outline the involvement of the right inferior frontal gyrus (IFG) as another putative compensatory locus in stuttering and suggest a role for this structure in an expanded core timing-network. Subsequently, we review behavioral studies of timing in people who stutter and examine their behavioral performance as compared to people who do not stutter. Finally, we highlight challenges to existing research and provide avenues for future research with specific hypotheses. PMID:25009487

  10. Neuroimaging in tuberculous meningitis.

    PubMed

    Garg, Ravindra Kumar; Malhotra, Hardeep Singh; Jain, Amita

    2016-01-01

    Tuberculous meningitis is a serious infection caused by Mycobacterium tuberculosis. Early diagnosis is the key to success of treatment. Neuroimaging plays a crucial role in the early and accurate diagnosis of tuberculous meningitis and its disabling complications. Magnetic resonance imaging is considered superior to computed tomography. Neuroimaging characteristics include leptomeningeal and basal cisternal enhancement, hydrocephalus, periventricular infarcts, and tuberculoma. Partially treated pyogenic meningitis, cryptococcal meningitis, viral encephalitis, carcinomatous, and lymphomatous meningitis may have many similar neuroimaging characteristics, and differentiation from tuberculous meningitis at times on the basis of neuroimaging characteristics becomes difficult. PMID:26954796

  11. The Brain Basis of Positive and Negative Affect: Evidence from a Meta-Analysis of the Human Neuroimaging Literature.

    PubMed

    Lindquist, Kristen A; Satpute, Ajay B; Wager, Tor D; Weber, Jochen; Barrett, Lisa Feldman

    2016-05-01

    The ability to experience pleasant or unpleasant feelings or to represent objects as "positive" or "negative" is known as representing hedonic "valence." Although scientists overwhelmingly agree that valence is a basic psychological phenomenon, debate continues about how to best conceptualize it scientifically. We used a meta-analysis of 397 functional magnetic resonance imaging (fMRI) and positron emission tomography studies (containing 914 experimental contrasts and 6827 participants) to test 3 competing hypotheses about the brain basis of valence: the bipolarity hypothesis that positive and negative affect are supported by a brain system that monotonically increases and/or decreases along the valence dimension, the bivalent hypothesis that positive and negative affect are supported by independent brain systems, and the affective workspace hypothesis that positive and negative affect are supported by a flexible set of valence-general regions. We found little evidence for the bipolar or bivalent hypotheses. Findings instead supported the hypothesis that, at the level of brain activity measurable by fMRI, valence is flexibly implemented across instances by a set of valence-general limbic and paralimbic brain regions. PMID:25631056

  12. Schizophrenia, neuroimaging and connectomics.

    PubMed

    Fornito, Alex; Zalesky, Andrew; Pantelis, Christos; Bullmore, Edward T

    2012-10-01

    Schizophrenia is frequently characterized as a disorder of brain connectivity. Neuroimaging has played a central role in supporting this view, with nearly two decades of research providing abundant evidence of structural and functional connectivity abnormalities in the disorder. In recent years, our understanding of how schizophrenia affects brain networks has been greatly advanced by attempts to map the complete set of inter-regional interactions comprising the brain's intricate web of connectivity; i.e., the human connectome. Imaging connectomics refers to the use of neuroimaging techniques to generate these maps which, combined with the application of graph theoretic methods, has enabled relatively comprehensive mapping of brain network connectivity and topology in unprecedented detail. Here, we review the application of these techniques to the study of schizophrenia, focusing principally on magnetic resonance imaging (MRI) research, while drawing attention to key methodological issues in the field. The published findings suggest that schizophrenia is associated with a widespread and possibly context-independent functional connectivity deficit, upon which are superimposed more circumscribed, context-dependent alterations associated with transient states of hyper- and/or hypo-connectivity. In some cases, these changes in inter-regional functional coupling dynamics can be related to measures of intra-regional dysfunction. Topological disturbances of functional brain networks in schizophrenia point to reduced local network connectivity and modular structure, as well as increased global integration and network robustness. Some, but not all, of these functional abnormalities appear to have an anatomical basis, though the relationship between the two is complex. By comprehensively mapping connectomic disturbances in patients with schizophrenia across the entire brain, this work has provided important insights into the highly distributed character of neural

  13. Specific disgust processing in the left insula: New evidence from direct electrical stimulation.

    PubMed

    Papagno, Costanza; Pisoni, Alberto; Mattavelli, Giulia; Casarotti, Alessandra; Comi, Alessandro; Fumagalli, Francesca; Vernice, Mirta; Fava, Enrica; Riva, Marco; Bello, Lorenzo

    2016-04-01

    Neuropsychological and neuroimaging studies yielded controversial results concerning the specific role of the insula in recognizing the facial expression of disgust. To verify whether the insula has a selective role in facial disgust processing, emotion recognition was studied in thirteen patients during intraoperative stimulation of the insula in awake surgery performed for removal of a glioma close to this structure. Direct electrical stimulation of the left insula produced a general decrease in emotion recognition but only in the case of disgust there was a statistically significant detrimental effect (p=0.004). Happiness and anger were the best and the worst recognized emotion, respectively. The worst baseline performance with anger and, partly, fear could be explained with the involvement of the left temporal regions, striatum, and the connection between the striatum and the frontal lobe, as suggested in previous studies. Therefore, upon these intra-operative evidences, we argue for a selective role of the left insula in disgust recognition, although a (non significant) decrease in the recognition of other negative emotions was found. However, additional networks can develop, as demonstrated by the fact that disgust recognition was not impaired after surgery even in patients with insular resection in the current as in previous studies. PMID:26836143

  14. Electrical Neuroimaging with Irrotational Sources

    PubMed Central

    Grave de Peralta Menendez, Rolando; Gonzalez Andino, Sara

    2015-01-01

    This paper discusses theoretical aspects of the modeling of the sources of the EEG (i.e., the bioelectromagnetic inverse problem or source localization problem). Using the Helmholtz decomposition (HD) of the current density vector (CDV) of the primary current into an irrotational (I) and a solenoidal (S) part we show that only the irrotational part can contribute to the EEG measurements. In particular we present for the first time the HD of a dipole and of a pure irrotational source. We show that, for both kinds of sources, I extends all over the space independently of whether the source is spatially concentrated (as the dipole) or not. However, the divergence remains confined to a region coinciding with the expected location of the sources, confirming that it is the divergence rather than the CDV that really defines the spatial extension of the generators, from where it follows that an irrotational source model (ELECTRA) is always physiologically meaningful as long as the divergence remains confined to the brain. Finally we show that the irrotational source model remains valid for the most general electrodynamics model of the EEG in inhomogeneous anisotropic dispersive media and thus far beyond the (quasi) static approximation. PMID:26113873

  15. Ethics of neuroimaging after serious brain injury

    PubMed Central

    2014-01-01

    Background Patient outcome after serious brain injury is highly variable. Following a period of coma, some patients recover while others progress into a vegetative state (unresponsive wakefulness syndrome) or minimally conscious state. In both cases, assessment is difficult and misdiagnosis may be as high as 43%. Recent advances in neuroimaging suggest a solution. Both functional magnetic resonance imaging and electroencephalography have been used to detect residual cognitive function in vegetative and minimally conscious patients. Neuroimaging may improve diagnosis and prognostication. These techniques are beginning to be applied to comatose patients soon after injury. Evidence of preserved cognitive function may predict recovery, and this information would help families and health providers. Complex ethical issues arise due to the vulnerability of patients and families, difficulties interpreting negative results, restriction of communication to “yes” or “no” answers, and cost. We seek to investigate ethical issues in the use of neuroimaging in behaviorally nonresponsive patients who have suffered serious brain injury. The objectives of this research are to: (1) create an approach to capacity assessment using neuroimaging; (2) develop an ethics of welfare framework to guide considerations of quality of life; (3) explore the impact of neuroimaging on families; and, (4) analyze the ethics of the use of neuroimaging in comatose patients. Methods/Design Our research program encompasses four projects and uses a mixed methods approach. Project 1 asks whether decision making capacity can be assessed in behaviorally nonresponsive patients. We will specify cognitive functions required for capacity and detail their assessment. Further, we will develop and pilot a series of scenarios and questions suitable for assessing capacity. Project 2 examines the ethics of welfare as a guide for neuroimaging. It grounds an obligation to explore patients’ interests, and we

  16. Neuroimaging of epilepsy.

    PubMed

    Cendes, Fernando; Theodore, William H; Brinkmann, Benjamin H; Sulc, Vlastimil; Cascino, Gregory D

    2016-01-01

    Imaging is pivotal in the evaluation and management of patients with seizure disorders. Elegant structural neuroimaging with magnetic resonance imaging (MRI) may assist in determining the etiology of focal epilepsy and demonstrating the anatomical changes associated with seizure activity. The high diagnostic yield of MRI to identify the common pathological findings in individuals with focal seizures including mesial temporal sclerosis, vascular anomalies, low-grade glial neoplasms and malformations of cortical development has been demonstrated. Positron emission tomography (PET) is the most commonly performed interictal functional neuroimaging technique that may reveal a focal hypometabolic region concordant with seizure onset. Single photon emission computed tomography (SPECT) studies may assist performance of ictal neuroimaging in patients with pharmacoresistant focal epilepsy being considered for neurosurgical treatment. This chapter highlights neuroimaging developments and innovations, and provides a comprehensive overview of the imaging strategies used to improve the care and management of people with epilepsy. PMID:27430454

  17. Functional neuroimaging in psychiatry.

    PubMed Central

    Fu, C H; McGuire, P K

    1999-01-01

    Functional neuroimaging is one of the most powerful means available for investigating the pathophysiology of psychiatric disorders. In this review, we shall focus on the different ways that it can be employed to this end, describing the major findings in the field in the context of different methodological approaches. We will also discuss practical issues that are particular to studying psychiatric disorders and the potential contribution of functional neuroimaging to future psychiatric research. PMID:10466156

  18. Turner Syndrome: Neuroimaging Findings--Structural and Functional

    ERIC Educational Resources Information Center

    Mullaney, Ronan; Murphy, Declan

    2009-01-01

    Neuroimaging studies of Turner syndrome can advance our understanding of the X chromosome in brain development, and the modulatory influence of endocrine factors. There is increasing evidence from neuroimaging studies that TX individuals have significant differences in the anatomy, function, and metabolism of a number of brain regions; including…

  19. Childhood-Onset Schizophrenia: Insights from Neuroimaging Studies

    ERIC Educational Resources Information Center

    Gogtay, Nitin; Rapoport, Judith L.

    2008-01-01

    The use of longitudinal neuroimaging to study the developmental perspectives of brain pathology in children with childhood-onset schizophrenia (COS) is described. Structural neuroimaging is capable of providing evidence of neurobiological specificity of COS to distinguish it from other brain abnormalities seen in neuropsychiatric illnesses like…

  20. Neuroimaging of neurocutaneous diseases.

    PubMed

    Nandigam, Kaveer; Mechtler, Laszlo L; Smirniotopoulos, James G

    2014-02-01

    An in-depth knowledge of the imaging characteristics of the common neurocutaneous diseases (NCD) described in this article will help neurologists understand the screening imaging modalities in these patients. The future of neuroimaging is geared towards developing and refining magnetic resonance imaging (MRI) sequences. The detection of tumors in NCD has greatly improved with availability of high-field strength 3T MRI machines. Neuroimaging will remain at the heart and soul of the multidisciplinary care of such complex diagnoses to guide early detection and monitor treatment. PMID:24287389

  1. Introduction to neuroimaging

    SciTech Connect

    Orrison, W.W.

    1989-01-01

    The author focuses on neuroradiology with emphasis on the current imaging modalities. There are chapters on angiography, myelography, nuclear medicine, ultrasonography, computer tomography (CT), and magnetic resonance (MR) imaging. The other chapters are dedicated to the spine, skull, head and neck, and pediatric neuroimaging.

  2. Neuroimaging and Psychopharmacology

    ERIC Educational Resources Information Center

    Semrud-Clikeman, Margaret; Pliszka, Steve R.

    2005-01-01

    This review presents the most recent research concerning neuroimaging in developmental disabilities. Changes in structure and activation have been found in children with ADHD and learning disabilities, following intervention. For the children with learning disabilities changes in activation have been found following intensive behavioral and…

  3. Neuromarketing: the hope and hype of neuroimaging in business

    PubMed Central

    Ariely, Dan; Berns, Gregory S.

    2010-01-01

    The application of neuroimaging methods to product marketing — neuromarketing — has recently gained considerable popularity. We propose that there are two main reasons for this trend. First, the possibility that neuroimaging will become cheaper and faster than other marketing methods; and second, the hope that neuroimaging will provide marketers with information that is not obtainable through conventional marketing methods. Although neuroimaging is unlikely to be cheaper than other tools in the near future, there is growing evidence that it may provide hidden information about the consumer experience. The most promising application of neuroimaging methods to marketing may come before a product is even released — when it is just an idea being developed. PMID:20197790

  4. Neuroimaging and plasticity in schizophrenia.

    PubMed

    Meyer-Lindenberg, Andreas; Tost, Heike

    2014-01-01

    Schizophrenia is a frequent and highly heritable brain disorder that typically manifests around or after puberty and has a fluctuating course. Multiple lines of evidence point to a neurodevelopmental origin of the illness and suggest that its (post) pubertal manifestation is related to genetic and environmental risk factors that interfere with the structural and functional reorganization of neural networks at this time. Longitudinal structural neuroimaging studies point to a progressive reduction in gray matter volume in many brain regions in schizophrenia. It has been proposed that these neuroimaging observations reflect an enduring disturbance of experience-dependent synaptic plasticity arising from developmental abnormalities in key neural circuits implicated in schizophrenia, including dorsolateral prefrontal cortex and hippocampal formation. Recent work has identified genetic variants linked to neural plasticity that are associated with changes in these circuits. Furthermore, non-invasive interventions such as transcranial magnetic stimulation have been shown to impact some of these systems-level intermediate phenotypes, suggesting a modifiability of these core pathophysiological processes of schizophrenia that may be exploited by therapy. PMID:23902983

  5. [Functional neuroimaging of addiction].

    PubMed

    Takahashi, Hidehiko

    2015-09-01

    Positron emission tomography studies investigating dopamine release by drug or reward demonstrated blunted dopamine release in relation to addiction to psychostimulants such as cocaine and amphetamine. However, recent studies reported that nicotine and gambling addiction showed opposite results. Several factors such as illness stage or neurotoxicity of substances could be considered for this discrepancy. Behavioral addiction such as gambling disorder is a good target of neuroimaging because it is free from overt neurotoxicity. However, even in gambling disorder, the results of fMRI studies investigating neural response to reward are mixed. Neuroimaging together with taking the various backgrounds of patients into account should contribute not only to a better understanding of the neurobiology of addiction but also to the development of more effective and individually tailored treatment strategies for addiction. PMID:26394506

  6. Functional neuroimaging of autobiographical memory.

    PubMed

    Cabeza, Roberto; St Jacques, Peggy

    2007-05-01

    Functional neuroimaging studies of autobiographical memory have grown dramatically in recent years. These studies are important because they can investigate the neural correlates of processes that are difficult to study using laboratory stimuli, including: (i) complex constructive processes, (ii) recollective qualities of emotion and vividness, and (iii) remote memory retrieval. Constructing autobiographical memories involves search, monitoring and self-referential processes that are associated with activity in separable prefrontal regions. The contributions of emotion and vividness have been linked to the amygdala and visual cortex respectively. Finally, there is evidence that recent and remote autobiographical memories might activate the hippocampus equally, which has implications for memory-consolidation theories. The rapid development of innovative methods for eliciting personal memories in the scanner provides the opportunity to delve into the functional neuroanatomy of our personal past. PMID:17382578

  7. A review of neuroimaging studies of stressor-evoked blood pressure reactivity: Emerging evidence for a brain-body pathway to coronary heart disease risk

    PubMed Central

    Gianaros, Peter J.; Sheu, Lei K.

    2009-01-01

    An individual's tendency to show exaggerated or otherwise dysregulated cardiovascular reactions to acute stressors has long been associated with increased risk for clinical and preclinical endpoints of coronary heart disease (CHD). However, the ‘brain-body’ pathways that link stressor-evoked cardiovascular reactions to CHD risk remain uncertain. This review summarizes emerging neuroimaging research indicating that individual differences in stressor-evoked blood pressure reactivity (a particular form of cardiovascular reactivity) are associated with activation patterns in corticolimbic brain areas that are jointly involved in processing stressors and regulating the cardiovascular system. As supported empirically by activation likelihood estimates derived from a meta-analysis, these corticolimbic areas include divisions of the cingulate cortex, insula, and amygdala—as well as networked cortical and subcortical areas involved in mobilizing hemodynamic and metabolic support for stress-related behavioral responding. Contextually, the research reviewed here illustrates how behavioral medicine and health neuroscience methods can be integrated to help characterize the ‘brain-body’ pathways that mechanistically link stressful experiences with CHD risk. PMID:19410652

  8. Neuroimaging resilience to stress: a review

    PubMed Central

    van der Werff, S. J. A.; van den Berg, S. M.; Pannekoek, J. N.; Elzinga, B. M.; van der Wee, N. J. A.

    2013-01-01

    There is a high degree of intra-individual variation in how individuals respond to stress. This becomes evident when exploring the development of posttraumatic symptoms or stress-related disorders after exposure to trauma. Whether or not an individual develops posttraumatic symptoms after experiencing a traumatic event is partly dependent on a person's resilience. Resilience can be broadly defined as the dynamic process encompassing positive adaptation within the context of significant adversity. Even though research into the neurobiological basis of resilience is still in its early stages, these insights can have important implications for the prevention and treatment of stress-related disorders. Neuroimaging studies contribute to our knowledge of intra-individual variability in resilience and the development of posttraumatic symptoms or other stress-related disorders. This review provides an overview of neuroimaging findings related to resilience. Structural, resting-state, and task-related neuroimaging results associated with resilience are discussed. There are a limited number of studies available and neuroimaging research of resilience is still in its infancy. The available studies point at brain circuitries involved in stress and emotion regulation, with more efficient processing and regulation associated with resilience. PMID:23675330

  9. Systematic Redaction for Neuroimage Data

    PubMed Central

    Matlock, Matt; Schimke, Nakeisha; Kong, Liang; Macke, Stephen; Hale, John

    2013-01-01

    In neuroscience, collaboration and data sharing are undermined by concerns over the management of protected health information (PHI) and personal identifying information (PII) in neuroimage datasets. The HIPAA Privacy Rule mandates measures for the preservation of subject privacy in neuroimaging studies. Unfortunately for the researcher, the management of information privacy is a burdensome task. Wide scale data sharing of neuroimages is challenging for three primary reasons: (i) A dearth of tools to systematically expunge PHI/PII from neuroimage data sets, (ii) a facility for tracking patient identities in redacted datasets has not been produced, and (iii) a sanitization workflow remains conspicuously absent. This article describes the XNAT Redaction Toolkit—an integrated redaction workflow which extends a popular neuroimage data management toolkit to remove PHI/PII from neuroimages. Quickshear defacing is also presented as a complementary technique for deidentifying the image data itself. Together, these tools improve subject privacy through systematic removal of PII/PHI. PMID:24179597

  10. A case study in electricity regulation: Theory, evidence, and policy

    NASA Astrophysics Data System (ADS)

    Luk, Stephen Kai Ming

    This research provides a thorough empirical analysis of the problem of excess capacity found in the electricity supply industry in Hong Kong. I utilize a cost-function based temporary equilibrium framework to investigate empirically whether the current regulatory scheme encourages the two utilities to overinvest in capital, and how much consumers would have saved if the underutilized capacity is eliminated. The research is divided into two main parts. The first section attempts to find any evidence of over-investment in capital. As a point of departure from traditional analysis, I treat physical capital as quasi-fixed, which implies a restricted cost function to represent the firm's short-run cost structure. Under such specification, the firm minimizes the cost of employing variable factor inputs subject to predetermined levels of quasi-fixed factors. Using a transcendental logarithmic restricted cost function, I estimate the cost-side equivalent of marginal product of capital, or commonly referred to as "shadow values" of capital. The estimation results suggest that the two electric utilities consistently over-invest in generation capacity. The second part of this research focuses on the economies of capital utilization, and the estimation of distortion cost in capital investment. Again, I utilize a translog specification of the cost function to estimate the actual cost of the excess capacity, and to find out how much consumers could have saved if the underutilized generation capacity were brought closer to the international standard. Estimation results indicate that an increase in the utilization rate can significantly reduce the costs of both utilities. And if the current excess capacity were reduced to the international standard, the combined savings in costs for both firms will reach 4.4 billion. This amount of savings, if redistributed to all consumers evenly, will translate into a 650 rebate per capita. Finally, two policy recommendations: a more stringent

  11. Neuroimaging of Cognition

    PubMed Central

    Dolan, R.J.

    2009-01-01

    Neuroimaging, particularly that based upon functional magnetic resonance (fMRI), has become a dominant tool in cognitive neuroscience. This review provides a personal and selective perspective on its past, present, and future. Two trends currently characterize the field that broadly reflect a pursuit of “where”- and “how”-type questions. The latter addresses basic mechanisms related to the expression of task-induced neural activity and is likely to be an increasingly important theme in the future. This trend entails an enhanced symbiosis among investigators pursuing similar questions in fields such as computational and theoretical neuroscience as well as through the detailed analysis of microcircuitry. PMID:18995825

  12. Demand Response in U.S. Electricity Markets: Empirical Evidence

    SciTech Connect

    Cappers, Peter; Goldman, Charles; Kathan, David

    2009-06-01

    Empirical evidence concerning demand response (DR) resources is needed in order to establish baseline conditions, develop standardized methods to assess DR availability and performance, and to build confidence among policymakers, utilities, system operators, and stakeholders that DR resources do offer a viable, cost-effective alternative to supply-side investments. This paper summarizes the existing contribution of DR resources in U.S. electric power markets. In 2008, customers enrolled in existing wholesale and retail DR programs were capable of providing ~;;38,000 MW of potential peak load reductions in the United States. Participants in organized wholesale market DR programs, though, have historically overestimated their likely performance during declared curtailments events, but appear to be getting better as they and their agents gain experience. In places with less developed organized wholesale market DR programs, utilities are learning how to create more flexible DR resources by adapting legacy load management programs to fit into existing wholesale market constructs. Overall, the development of open and organized wholesale markets coupled with direct policy support by the Federal Energy Regulatory Commission has facilitated new entry by curtailment service providers, which has likely expanded the demand response industry and led to product and service innovation.

  13. Data sharing in neuroimaging research

    PubMed Central

    Poline, Jean-Baptiste; Breeze, Janis L.; Ghosh, Satrajit; Gorgolewski, Krzysztof; Halchenko, Yaroslav O.; Hanke, Michael; Haselgrove, Christian; Helmer, Karl G.; Keator, David B.; Marcus, Daniel S.; Poldrack, Russell A.; Schwartz, Yannick; Ashburner, John; Kennedy, David N.

    2012-01-01

    Significant resources around the world have been invested in neuroimaging studies of brain function and disease. Easier access to this large body of work should have profound impact on research in cognitive neuroscience and psychiatry, leading to advances in the diagnosis and treatment of psychiatric and neurological disease. A trend toward increased sharing of neuroimaging data has emerged in recent years. Nevertheless, a number of barriers continue to impede momentum. Many researchers and institutions remain uncertain about how to share data or lack the tools and expertise to participate in data sharing. The use of electronic data capture (EDC) methods for neuroimaging greatly simplifies the task of data collection and has the potential to help standardize many aspects of data sharing. We review here the motivations for sharing neuroimaging data, the current data sharing landscape, and the sociological or technical barriers that still need to be addressed. The INCF Task Force on Neuroimaging Datasharing, in conjunction with several collaborative groups around the world, has started work on several tools to ease and eventually automate the practice of data sharing. It is hoped that such tools will allow researchers to easily share raw, processed, and derived neuroimaging data, with appropriate metadata and provenance records, and will improve the reproducibility of neuroimaging studies. By providing seamless integration of data sharing and analysis tools within a commodity research environment, the Task Force seeks to identify and minimize barriers to data sharing in the field of neuroimaging. PMID:22493576

  14. Neuroimaging distinction between neurological and psychiatric disorders†

    PubMed Central

    Crossley, Nicolas A.; Scott, Jessica; Ellison-Wright, Ian; Mechelli, Andrea

    2015-01-01

    Background It is unclear to what extent the traditional distinction between neurological and psychiatric disorders reflects biological differences. Aims To examine neuroimaging evidence for the distinction between neurological and psychiatric disorders. Method We performed an activation likelihood estimation meta-analysis on voxel-based morphometry studies reporting decreased grey matter in 14 neurological and 10 psychiatric disorders, and compared the regional and network-level alterations for these two classes of disease. In addition, we estimated neuroanatomical heterogeneity within and between the two classes. Results Basal ganglia, insula, sensorimotor and temporal cortex showed greater impairment in neurological disorders; whereas cingulate, medial frontal, superior frontal and occipital cortex showed greater impairment in psychiatric disorders. The two classes of disorders affected distinct functional networks. Similarity within classes was higher than between classes; furthermore, similarity within class was higher for neurological than psychiatric disorders. Conclusions From a neuroimaging perspective, neurological and psychiatric disorders represent two distinct classes of disorders. PMID:26045351

  15. Neuroimaging of Graves' orbitopathy.

    PubMed

    Müller-Forell, Wibke; Kahaly, George J

    2012-06-01

    Neuroimaging of Graves' orbitopathy (GO) plays an important role in the differential diagnosis and interdisciplinary management of patients with GO. Orbital imaging is required in unclear or asymmetric proptosis, in suspected optic neuropathy and prior to decompression surgery. Especially computed tomography and magnetic resonance (MR) imaging show the actual objective morphological findings, quantitative MR imaging giving additional information concerning the acuteness or chronicity of the disease. Major morphological diagnostic criteria include a spindle like spreading of the rectus muscles without involvement of the tendon, a compression of the optic nerve in the orbital apex (crowded orbital apex syndrome) and the absence of any space occupying intraorbital process. A longer lasting course of the disease may lead to a corresponding impression of the lamina papyracae, the normally parallel configured medial wall of the orbit, similar to a spontaneous decompression. PMID:22632363

  16. Provenance in neuroimaging.

    PubMed

    Mackenzie-Graham, Allan J; Van Horn, John D; Woods, Roger P; Crawford, Karen L; Toga, Arthur W

    2008-08-01

    Provenance, the description of the history of a set of data, has grown more important with the proliferation of research consortia-related efforts in neuroimaging. Knowledge about the origin and history of an image is crucial for establishing data and results quality; detailed information about how it was processed, including the specific software routines and operating systems that were used, is necessary for proper interpretation, high fidelity replication and re-use. We have drafted a mechanism for describing provenance in a simple and easy to use environment, alleviating the burden of documentation from the user while still providing a rich description of an image's provenance. This combination of ease of use and highly descriptive metadata should greatly facilitate the collection of provenance and subsequent sharing of data. PMID:18519166

  17. Neuroimaging in ophthalmology

    PubMed Central

    Kim, James D.; Hashemi, Nafiseh; Gelman, Rachel; Lee, Andrew G.

    2012-01-01

    In the past three decades, there have been countless advances in imaging modalities that have revolutionized evaluation, management, and treatment of neuro-ophthalmic disorders. Non-invasive approaches for early detection and monitoring of treatments have decreased morbidity and mortality. Understanding of basic methods of imaging techniques and choice of imaging modalities in cases encountered in neuro-ophthalmology clinic is critical for proper evaluation of patients. Two main imaging modalities that are often used are computed tomography (CT) and magnetic resonance imaging (MRI). However, variations of these modalities and appropriate location of imaging must be considered in each clinical scenario. In this article, we review and summarize the best neuroimaging studies for specific neuro-ophthalmic indications and the diagnostic radiographic findings for important clinical entities. PMID:23961025

  18. Neuroimaging: beginning to appreciate its complexities.

    PubMed

    Parens, Erik; Johnston, Josephine

    2014-01-01

    For over a century, scientists have sought to see through the protective shield of the human skull and into the living brain. Today, an array of technologies allows researchers and clinicians to create astonishingly detailed images of our brain's structure as well as colorful depictions of the electrical and physiological changes that occur within it when we see, hear, think and feel. These technologies-and the images they generate-are an increasingly important tool in medicine and science. Given the role that neuroimaging technologies now play in biomedical research, both neuroscientists and nonexperts should aim to be as clear as possible about how neuroimages are made and what they can-and cannot-tell us. Add to this that neuroimages have begun to be used in courtrooms at both the determination of guilt and sentencing stages, that they are being employed by marketers to refine advertisements and develop new products, that they are being sold to consumers for the diagnosis of mental disorders and for the detection of lies, and that they are being employed in arguments about the nature (or absence) of powerful concepts like free will and personhood, and the need for citizens to have a basic understanding of how this technology works and what it can and cannot tell us becomes even more pressing. PMID:24634082

  19. Neuroimaging findings in treatment-resistant schizophrenia: a systematic review

    PubMed Central

    Nakajima, Shinichiro; Takeuchi, Hiroyoshi; Plitman, Eric; Fervaha, Gagan; Gerretsen, Philip; Caravaggio, Fernando; Chung, Jun Ku; Iwata, Yusuke; Remington, Gary; Graff-Guerrero, Ariel

    2015-01-01

    Background Recent developments in neuroimaging have advanced understanding biological mechanisms underlying schizophrenia. However, neuroimaging correlates of treatment-resistant schizophrenia (TRS) and superior effects of clozapine on TRS remain unclear. Methods Systematic search was performed to identify neuroimaging characteristics unique to TRS and ultra-resistant schizophrenia (i.e. clozapine-resistant [URS]), and clozapine's efficacy in TRS using Embase, Medline, and PsychInfo. Search terms included (schizophreni*) and (resistan* OR refractory OR clozapine) and (ASL OR CT OR DTI OR FMRI OR MRI OR MRS OR NIRS OR PET OR SPECT). Results 25 neuroimaging studies have investigated TRS and effects of clozapine. Only 5 studies have compared TRS and non-TRS, collectively providing no replicated neuroimaging finding specific to TRS. Studies comparing TRS and healthy controls suggest hypometabolism in the prefrontal cortex, hypermetabolism in the basal ganglia, and structural anomalies in the corpus callosum contribute to TRS. Clozapine may increase prefrontal hypoactivation in TRS although this was not related to clinical improvement; in contrast, evidence has suggested a link between clozapine efficacy and decreased metabolism in the basal ganglia and thalamus. Conclusion Existing literature does not elucidate neuroimaging correlates specific to TRS or URS, which, if present, might also shed light on clozapine's efficacy in TRS. This said, leads from other lines of investigation, including the glutamatergic system can prove useful in guiding future neuroimaging studies focused on, in particular, the frontocortical-basal ganglia-thalamic circuits. Critical to the success of this work will be precise subtyping of study subjects based on treatment response/nonresponse and the use of multimodal neuroimaging. PMID:25684554

  20. Can structural neuroimaging be used to define phenotypes and course of schizophrenia?

    PubMed

    Kerns, John G; Lauriello, John

    2012-09-01

    This article examines whether structural neuroimaging measures have been found to predict outcome in schizophrenia and whether changes in neuroimaging measures have been found to correlate with poor outcome in the disorder. Overall, there is little compelling evidence that structural neuroimaging measures in either first-episode or chronic patients predict future outcome. Progressive brain changes might reflect a neuroimaging phenotype associated with a worse course of the disorder. At the same time, there are many fruitful avenues that future research could take in an attempt to better predict future outcome or to identify specific imaging phenotypes associated with outcome. PMID:22929870

  1. Effects of the South American psychoactive beverage ayahuasca on regional brain electrical activity in humans: a functional neuroimaging study using low-resolution electromagnetic tomography.

    PubMed

    Riba, Jordi; Anderer, Peter; Jané, Francesc; Saletu, Bernd; Barbanoj, Manel J

    2004-01-01

    Ayahuasca, a South American psychotropic plant tea obtained from Banisteriopsis caapi and Psychotria viridis, combines monoamine oxidase-inhibiting beta-carboline alkaloids with N,N-dimethyltryptamine (DMT), a psychedelic agent showing 5-HT(2A) agonist activity. In a clinical research setting, ayahuasca has demonstrated a combined stimulatory and psychedelic effect profile, as measured by subjective effect self-assessment instruments and dose-dependent changes in spontaneous brain electrical activity, which parallel the time course of subjective effects. In the present study, the spatial distribution of ayahuasca-induced changes in brain electrical activity was investigated by means of low-resolution electromagnetic tomography (LORETA). Electroencephalography recordings were obtained from 18 volunteers after the administration of a dose of encapsulated freeze-dried ayahuasca containing 0.85 mg DMT/kg body weight and placebo. The intracerebral power density distribution was computed with LORETA from spectrally analyzed data, and subjective effects were measured by means of the Hallucinogen Rating Scale (HRS). Statistically significant differences compared to placebo were observed for LORETA power 60 and 90 min after dosing, together with increases in all six scales of the HRS. Ayahuasca decreased power density in the alpha-2, delta, theta and beta-1 frequency bands. Power decreases in the delta, alpha-2 and beta-1 bands were found predominantly over the temporo-parieto-occipital junction, whereas theta power was reduced in the temporomedial cortex and in frontomedial regions. The present results suggest the involvement of unimodal and heteromodal association cortex and limbic structures in the psychological effects elicited by ayahuasca. PMID:15179026

  2. Neuroimaging features of tuberculous meningitis.

    PubMed

    Sobri, M; Merican, J S; Nordiyana, M; Valarmathi, S; Ai-Edrus, S A

    2006-03-01

    Tuberculous meningitis leads to a high mortality rate. However, it responds well to chemotherapy if the treatment is started early. Neuroimaging is one of the most important initial investigations. There were 42 patients diagnosed with tuberculous meningitis in Kuala Lumpur Hospital based on clinical criteria, cerebrospinal fluid analysis and response to anti-tuberculous treatment over a 7 year period. Relevant information was obtained from patients' medical case notes and neuroimaging findings were evaluated. Male to female ratio was 3:1. The three major ethnics and the immigrant groups in Malaysia were represented in this study. The majority of the cases involved the Malays followed by immigrants, Chinese and Indians. The patients' age ranged from 18 to 62 years old with the mean age of 34.4 years. There were 95.2% (n = 40) of patients who presented with various neuroimaging abnormalities and only 2 (4.8%) patients had normal neuroimaging findings. Hydrocephalus and meningeal enhancement were the two commonest neuroimaging features. Other features include infarction, enhancing lesion, tuberculoma, abcess, oedema and calcification. Contrasted CT scan is an adequate neuroimaging tool to unmask abnormal findings in tuberculous meningitis. PMID:16708732

  3. Neuroimaging in anxiety disorders.

    PubMed

    Fredrikson, Mats; Faria, Vanda

    2013-01-01

    Neuroimaging studies using functional magnetic resonance imaging (fMRI), positron emission tomography (PET) and single-photon emission computed tomography (SPECT) to evaluate neurofunctional and neurochemical alterations related to the generation and control of affect in patients with anxiety disorders are reviewed. We performed a meta-analysis of symptom provocation studies, where neural activity was measured using fMRI, PET or SPECT to test the hypothesis that prefrontal regions modulate amygdala activity. Data revealed that reactivity in the amygdala was enhanced in patients with phobia as well as posttraumatic stress disorder (PTSD). The dorsal anterior cingulate cortex was activated in concert with the amygdala, both in PTSD and in phobic states, suggesting a role in fear expression, rather than emotional control. Activity in emotion-regulating areas in the ventromedial prefrontal cortex including the subgenual anterior cingulate cortex and the medial orbitofrontal cortex was compromised in the symptomatic state in PTSD and phobic disorders, respectively. Increased amygdala reactivity was restored with psychological treatment. Treatment effects across different modalities including pharmacological and psychological interventions as well as with placebo regimens support that reduction of neural activity in the amygdala may be a final common pathway for successful therapeutic interventions irrespective of method, thereby linking neurotransmission to plasticity in a pivotal node of the core fear network of the brain. PMID:25225017

  4. Neuroimaging of spine tumors.

    PubMed

    Pinter, Nandor K; Pfiffner, Thomas J; Mechtler, Laszlo L

    2016-01-01

    Intramedullary, intradural/extramedullary, and extradural spine tumors comprise a wide range of neoplasms with an even wider range of clinical symptoms and prognostic features. Magnetic resonance imaging (MRI), commonly used to evaluate the spine in patients presenting with pain, can further characterize lesions that may be encountered on other imaging studies, such as bone scintigraphy or computed tomography (CT). The advantage of the MRI is its multiplane capabilities, superior contrast agent resolution, and flexible protocols that play an important role in assessing tumor location, extent in directing biopsy, in planning proper therapy, and in evaluating therapeutic results. A multimodality approach can be used to fully characterize the lesion and the combination of information obtained from the different modalities usually narrows the diagnostic possibilities significantly. The diagnosis of spinal tumors is based on patient age, topographic features of the tumor, and lesion pattern, as seen at CT and MRI. The shift to high-end imaging incorporating diffusion-weighted imaging, diffusion tensor imaging, magnetic resonance spectroscopy, whole-body short tau inversion recovery, positron emission tomography, intraoperative and high-field MRI as part of the mainstream clinical imaging protocol has provided neurologists, neuro-oncologists, and neurosurgeons a window of opportunity to assess the biologic behavior of spine neoplasms. This chapter reviews neuroimaging of spine tumors, primary and secondary, discussing routine and newer modalities that can reduce the significant morbidity associated with these neoplasms. PMID:27430436

  5. Electric field evidence for tailward flow at substorm onset

    NASA Technical Reports Server (NTRS)

    Nishida, A.; Tulunay, Y. K.; Mozer, F. S.; Cattell, C. A.; Hones, E. W., Jr.; Birn, J.

    1983-01-01

    Electric field observations made near the neutral sheet of the magnetotail provide additional support for the view that reconnection occurs in the near-earth region of the tail. Southward turnings of the magnetic field that start at, or shortly after, substorm onsets are accompanied by enhancements in the dawn-to-dusk electric field, resulting in a tailward E x B drift velocity. Both the magnetic and the electric fields in the tailward-flowing plasma are nonuniform and vary with inferred spatial scales of several earth radii in the events examined in this paper. These nonuniformities may be the consequence of the tearing-mode process. The E x B flow was also towards the neutral sheet and away from midnight in the events studied.

  6. Evidence for Subauroral Electric Fields from IMAGE EUV

    NASA Technical Reports Server (NTRS)

    Six, N. Frank (Technical Monitor); Gallagher, D.; Adrian, M.; Goldstein, J.; Sandel, B.

    2002-01-01

    The IMAGE Mission Extreme Ultraviolet Imager routinely provides global snapshots of the plasmasphere from high latitude. In these 10-minute images, intensity edges have been identified with the plasmapause and other strong gradients in plasmaspheric density. In addition to the classic sunward directed convection tail and its entrainment in corotation during storm-time recovery, the plasmapause boundary reveals a wide variety of structures thought to result from penetration of the solar wind induced convection electric field to subauroral latitudes. The so-called shoulder feature has most prominently been discussed in the context of under shielding in response to changes in the convection electric field strength. It is not yet clear whether all of the observed surface structures on the plasmasphere can be explained in this manner. The types of structures observed and their frequency of occurrence will be presented. A statistical view of these structures and associated solar wind conditions will also be presented.

  7. Electric field exposure and evidence of stress in mice

    SciTech Connect

    De Bruyn, L.; De Jager, L. )

    1994-04-01

    The effect of stress induced by an electric field on the adrenal gland cortex of mice was examined by means of corticosterone serum assay and evaluation of the lipid profile of the different zones of the cortex. Six generations of experimental mice were exposed to a 10 kV/m electric field from conception and corresponding control groups were sham exposed. Mice were sacrificed at 35 days (n = 10), as adults (n = 20) and at 18 months (old mice) (n = 10). Blinded lipid estimates were performed on histological preparations of the adrenals, serum corticosterone levels were determined, and the results were statistically analyzed. The mean lipid volume in the zona glomerulosa of the exposed adult male group was significantly higher than that of the control group (P = 0.004). The median daytime corticosterone level of the exposed male mice was also significantly higher than that in the controls (P = 0.02). The lipid profiles and corticosterone values in the other subgroups did not differ significantly. As chronic stress increases the lipid volume of all the zones of the adrenal cortex and stimulates the zona glomerulosa to corticosterone secretion, the data suggest that the electric field acted as a chronic stressor in the adult male mice. 21 refs., 6 figs., 2 tabs.

  8. Neuroimaging, culture, and forensic psychiatry.

    PubMed

    Aggarwal, Neil K

    2009-01-01

    The spread of neuroimaging technologies around the world has led to diverse practices of forensic psychiatry and the emergence of neuroethics and neurolaw. This article surveys the neuroethics and neurolegal literature on the use of forensic neuroimaging within the courtroom. Next, the related literature within medical anthropology and science and technology studies is reviewed to show how debates about forensic neuroimaging reflect cultural tensions about attitudes regarding the self, mental illness, and medical expertise. Finally, recommendations are offered on how forensic psychiatrists can add to this research, given their professional interface between law and medicine. At stake are the fundamental concerns that surround changing conceptions of the self, sickness, and expectations of medicine. PMID:19535562

  9. Recent Advances in Neuroimaging Biomarkers in Geriatric Psychiatry

    PubMed Central

    Khandai, Abhisek C.; Aizenstein, Howard J.

    2013-01-01

    Neuroimaging, both structural and functional, serve as useful adjuncts to clinical assessment, and can provide objective, reliable means of assessing disease presence and process in the aging population. In the following review we briefly explain current imaging methodologies. Then, we analyze recent developments in developing neuroimaging biomarkers for two highly prevalent disorders in the elderly population- Alzheimer's disease (AD) and late-life depression (LLD). In AD, efforts are focused on early diagnosis through in vivo visualization of disease pathophysiology. In LLD, recent imaging evidence supports the role of white matter ischemic changes in the pathogenesis of depression in the elderly, the “vascular hypothesis.” Finally, we discuss potential roles for neuroimaging biomarkers in geriatric psychiatry in the future. PMID:23636984

  10. Electric Properties of Obsidian: Evidence for Positive Hole Charge Carriers

    NASA Astrophysics Data System (ADS)

    Nordvik, R.; Freund, F. T.

    2012-12-01

    The blackness of obsidian is due to the presence of oxygen anions in the valence state 1-, creating broad energy levels at the upper edge of the valence band, which absorb visible light over a wide spectral range. These energy states are associated with defect electrons in the oxygen anion sublattice, well-known from "smoky quartz", where Al substituting for Si captures a defect electron in the oxygen anion sublattice for charge compensation [1]. Such defect electrons, also known as positive holes, are responsible for the increase in electrical conductivity in igneous rocks when uniaxial stresses are applied, causing the break-up of pre-existing peroxy defects, Si-OO-Si [2]. Peroxy defects in obsidian cannot be so easily activated by mechanical stress because the glassy matrix will break before sufficiently high stress levels can be reached. If peroxy defects do exist, however, they can be studied by activating them thermally [3]. We describe experiments with rectangular slabs of obsidian with Au electrodes at both ends. Upon heating one end, we observe (i) a thermopotential and (ii) a thermocurrent developing at distinct temperatures around 250°C and 450°C, marking the 2-step break-up of peroxy bonds. [1] Schnadt, R., and Schneider, J.: The electronic structure of the trapped-hole center in smoky quartz, Zeitschrift Physik B Condensed Matter 11, 19-42, 1970. [2] Freund, F. T., Takeuchi, A., and Lau, B. W.: Electric currents streaming out of stressed igneous rocks - A step towards understanding pre-earthquake low frequency EM emissions, Physics and Chemistry of the Earth, 31, 389-396, 2006. [3] Freund, F., and Masuda, M. M.: Highly mobile oxygen hole-type charge carriers in fused silica, Journal Material Research, 8, 1619-1622, 1991.

  11. Graphical neuroimaging informatics: application to Alzheimer's disease.

    PubMed

    Van Horn, John Darrell; Bowman, Ian; Joshi, Shantanu H; Greer, Vaughan

    2014-06-01

    The Informatics Visualization for Neuroimaging (INVIZIAN) framework allows one to graphically display image and meta-data information from sizeable collections of neuroimaging data as a whole using a dynamic and compelling user interface. Users can fluidly interact with an entire collection of cortical surfaces using only their mouse. In addition, users can cluster and group brains according in multiple ways for subsequent comparison using graphical data mining tools. In this article, we illustrate the utility of INVIZIAN for simultaneous exploration and mining a large collection of extracted cortical surface data arising in clinical neuroimaging studies of patients with Alzheimer's Disease, mild cognitive impairment, as well as healthy control subjects. Alzheimer's Disease is particularly interesting due to the wide-spread effects on cortical architecture and alterations of volume in specific brain areas associated with memory. We demonstrate INVIZIAN's ability to render multiple brain surfaces from multiple diagnostic groups of subjects, showcase the interactivity of the system, and showcase how INVIZIAN can be employed to generate hypotheses about the collection of data which would be suitable for direct access to the underlying raw data and subsequent formal statistical analysis. Specifically, we use INVIZIAN show how cortical thickness and hippocampal volume differences between group are evident even in the absence of more formal hypothesis testing. In the context of neurological diseases linked to brain aging such as AD, INVIZIAN provides a unique means for considering the entirety of whole brain datasets, look for interesting relationships among them, and thereby derive new ideas for further research and study. PMID:24203652

  12. Transcutaneous Electrical Nerve Stimulation: Mechanisms, Clinical Application and Evidence

    PubMed Central

    2007-01-01

    Transcutaneous electrical nerve stimulation (TENS) is a non-invasive, inexpensive, self-administered technique to relieve pain.There are few side effects and no potential for overdose so patients can titrate the treatment as required.TENS techniques include conventional TENS, acupuncture-like TENS and intense TENS. In general, conventional TENS is used in the first instance.The purpose of conventional TENS is to selectively activate large diameter non-noxious afferents (A-beta) to reduce nociceptor cell activity and sensitization at a segmental level in the central nervous system.Pain relief with conventional TENS is rapid in onset and offset and is maximal when the patient experiences a strong but non-painful paraesthesia beneath the electrodes. Therefore, patients may need to administer TENS throughout the day.Clinical experience suggests that TENS may be beneficial as an adjunct to pharmacotherapy for acute pain although systematic reviews are conflicting. Clinical experience and systematic reviews suggest that TENS is beneficial for chronic pain. PMID:26526976

  13. Neuroimaging of child abuse: a critical review

    PubMed Central

    Hart, Heledd; Rubia, Katya

    2012-01-01

    Childhood maltreatment is a stressor that can lead to the development of behavior problems and affect brain structure and function. This review summarizes the current evidence for the effects of childhood maltreatment on behavior, cognition and the brain in adults and children. Neuropsychological studies suggest an association between child abuse and deficits in IQ, memory, working memory, attention, response inhibition and emotion discrimination. Structural neuroimaging studies provide evidence for deficits in brain volume, gray and white matter of several regions, most prominently the dorsolateral and ventromedial prefrontal cortex but also hippocampus, amygdala, and corpus callosum (CC). Diffusion tensor imaging (DTI) studies show evidence for deficits in structural interregional connectivity between these areas, suggesting neural network abnormalities. Functional imaging studies support this evidence by reporting atypical activation in the same brain regions during response inhibition, working memory, and emotion processing. There are, however, several limitations of the abuse research literature which are discussed, most prominently the lack of control for co-morbid psychiatric disorders, which make it difficult to disentangle which of the above effects are due to maltreatment, the associated psychiatric conditions or a combination or interaction between both. Overall, the better controlled studies that show a direct correlation between childhood abuse and brain measures suggest that the most prominent deficits associated with early childhood abuse are in the function and structure of lateral and ventromedial fronto-limbic brain areas and networks that mediate behavioral and affect control. Future, large scale multimodal neuroimaging studies in medication-naïve subjects, however, are needed that control for psychiatric co-morbidities in order to elucidate the structural and functional brain sequelae that are associated with early environmental adversity

  14. The structural neuroimaging of bipolar disorder.

    PubMed

    Emsell, Louise; McDonald, Colm

    2009-01-01

    There is an increasing body of literature fuelled by advances in high-resolution structural MRI acquisition and image processing techniques which implicates subtle neuroanatomical abnormalities in the aetiopathogenesis of bipolar disorder. This account reviews the main findings from structural neuroimaging research into regional brain abnormalities, the impact of genetic liability and mood stabilizing medication on brain structure in bipolar disorder, and the overlapping structural deviations found in the allied disorders of schizophrenia and depression. The manifold challenges extant within neuroimaging research are highlighted with accompanying recommendations for future studies. The most consistent findings include preservation of total cerebral volume with regional grey and white matter structural changes in prefrontal, midline and anterior limbic networks, non-contingent ventriculomegaly and increased rates of white matter hyperintensities, with more pronounced deficits in juveniles suffering from the illness. There is increasing evidence that medication has observable effects on brain structure, whereby lithium status is associated with volumetric increase in the medial temporal lobe and anterior cingulate gyrus. However, research continues to be confounded by the use of highly heterogeneous methodology and clinical populations, in studies employing small scale, low-powered, cross-sectional designs. Future work should investigate larger, clinically homogenous groups of patients and unaffected relatives, combining both categorical and dimensional approaches to illness classification in cross-sectional and longitudinal designs in order to elucidate trait versus state mechanisms, genetic effects and medication/illness progression effects over time. PMID:20374145

  15. Application of fuzzy evidence theory in a photo-electric measurement system

    NASA Astrophysics Data System (ADS)

    Song, Jianxun; Xiong, Maotao; Zhang, Jin; Wu, Qinzhang

    2009-05-01

    The photo-electric measurement system is a kind of high-precision measurement system for trajectory parameters and object identity parameters, and it can acquire the image information of flying objects by CCD camera. Due to subject to some kinds of reasons, the feature information of image is not integrated and imprecise, and it has uncertainty and fuzzy in some degree. The Dempster-Shafer evidence theory is an important approach of uncertainty reasoning. With evidences fused, the uncertainty of the feature information of the object is declined gradually by Dempster combination rule, so it can achieve the aim of object detection and object recognition. The conception of fuzzy mass is expanded in the way of the relation of absolute membership on the basis of normal mass conception. The fuzzy theory is very suitable for the description and processing of uncertainty to evidences in D-S evidence theory, so the Basic Probability Assignment Function (BPAF) of D-S evidence theory can be acquired according to fuzzy theory, and it resolves crucial problem in D-S evidence theory. It is shown that data fusion method of fuzzy evidence theory can deal with uncertainty and the fuzzy of photo-electric measurement system according to the analysis of theory and the result of experimentation, and it has a bright future in photo-electric measurement systems.

  16. Neuroimaging for psychotherapy research: Current trends

    PubMed Central

    WEINGARTEN, CAROL P.; STRAUMAN, TIMOTHY J.

    2014-01-01

    Objective This article reviews neuroimaging studies that inform psychotherapy research. An introduction to neuroimaging methods is provided as background for the increasingly sophisticated breadth of methods and findings appearing in psychotherapy research. Method We compiled and assessed a comprehensive list of neuroimaging studies of psychotherapy outcome, along with selected examples of other types of studies that also are relevant to psychotherapy research. We emphasized magnetic resonance imaging (MRI) since it is the dominant neuroimaging modality in psychological research. Results We summarize findings from neuroimaging studies of psychotherapy outcome, including treatment for depression, obsessive-compulsive disorder (OCD), and schizophrenia. Conclusions The increasing use of neuroimaging methods in the study of psychotherapy continues to refine our understanding of both outcome and process. We suggest possible directions for future neuroimaging studies in psychotherapy research. PMID:24527694

  17. FUNCTIONAL NEUROIMAGING IN GERIATRIC DEPRESSION

    PubMed Central

    Gunning, Faith M.; Smith, Gwenn S.

    2012-01-01

    Synopsis Abnormalities in specific cerebral networks likely confer vulnerability that increases the susceptibility for development of geriatric depression and impact the course of symptoms. Functional neuroimaging enables the in vivo identification of alterations in cerebral function that not only characterize disease vulnerability, but also may contribute to variability in depressive symptoms and antidepressant response. Judicious use of functional neuroimaging tools can advance pathophysiological models of geriatric depression. Furthermore, due to the age-related vulnerability of specific brain systems that have been implicated in mood disorders, geriatric depression provides a logical context within which to study the role of specific functional abnormalities in both antidepressant response and key behavioral and cognitive abnormalities of mood disorders. PMID:21536165

  18. Computational Modeling and Neuroimaging Techniques for Targeting during Deep Brain Stimulation

    PubMed Central

    Sweet, Jennifer A.; Pace, Jonathan; Girgis, Fady; Miller, Jonathan P.

    2016-01-01

    Accurate surgical localization of the varied targets for deep brain stimulation (DBS) is a process undergoing constant evolution, with increasingly sophisticated techniques to allow for highly precise targeting. However, despite the fastidious placement of electrodes into specific structures within the brain, there is increasing evidence to suggest that the clinical effects of DBS are likely due to the activation of widespread neuronal networks directly and indirectly influenced by the stimulation of a given target. Selective activation of these complex and inter-connected pathways may further improve the outcomes of currently treated diseases by targeting specific fiber tracts responsible for a particular symptom in a patient-specific manner. Moreover, the delivery of such focused stimulation may aid in the discovery of new targets for electrical stimulation to treat additional neurological, psychiatric, and even cognitive disorders. As such, advancements in surgical targeting, computational modeling, engineering designs, and neuroimaging techniques play a critical role in this process. This article reviews the progress of these applications, discussing the importance of target localization for DBS, and the role of computational modeling and novel neuroimaging in improving our understanding of the pathophysiology of diseases, and thus paving the way for improved selective target localization using DBS. PMID:27445709

  19. Neuroimaging in multiple sclerosis.

    PubMed

    Zivadinov, Robert; Cox, Jennifer L

    2007-01-01

    Conventional magnetic resonance imaging (MRI) has routinely been used to improve the accuracy of multiple sclerosis (MS) diagnosis and prognosis. Metrics derived from conventional MRI are now routinely used to detect therapeutic effects and extend clinical observations. However, conventional MRI measures, such as the use of lesion volume and count of gadolinium-enhancing and T2 lesions, have insufficient sensitivity and specificity to reveal the true degree of pathological changes occurring in MS. They cannot distinguish between inflammation, edema, demyelination, Wallerian degeneration, and axonal loss. In addition, they do not show a reliable correlation with clinical measures of disability and do not provide a complete assessment of therapeutic outcomes. Recent neuropathologic studies of typical chronic MS brains reveal macroscopic demyelination in cortical and deep gray matter (GM) that cannot be detected by currently available MRI techniques. Therefore, there is a pressing need for the development of newer MRI techniques to detect these lesions. Newer metrics of MRI analysis, including T1-weighted hypointense lesions, central nervous system atrophy measures, magnetization transfer imaging, magnetic resonance spectroscopy, and diffusion tensor imaging, are able to capture a more global picture of the range of tissue alterations caused by inflammation and neurodegeneration. At this time, they provide the only proof--albeit indirect--that important occult pathology is occurring in the GM. However, evidence is increasing that these nonconventional MRI measures correlate better with both existing and developing neurological impairment and disability when compared to conventional metrics. PMID:17531854

  20. Neuroimaging of Aggressive and Violent Behaviour in Children and Adolescents

    PubMed Central

    Sterzer, Philipp; Stadler, Christina

    2009-01-01

    In recent years, a number of functional and structural neuroimaging studies have investigated the neural bases of aggressive and violent behaviour in children and adolescents. Most functional neuroimaging studies have persued the hypothesis that pathological aggression is a consequence of deficits in the neural circuits involved in emotion processing. There is converging evidence for abnormal neural responses to emotional stimuli in youths with a propensity towards aggressive behaviour. In addition, recent neuroimaging work has suggested that aggressive behaviour is also associated with abnormalities in neural processes that subserve both the inhibitory control of behaviour and the flexible adaptation of behaviour in accord with reinforcement information. Structural neuroimaging studies in children and adolescents with conduct problems are still scarce, but point to deficits in brain structures in volved in the processing of social information and in the regulation of social and goal-directed behaviour. The indisputable progress that this research field has made in recent years notwithstanding, the overall picture is still rather patchy and there are inconsistencies between studies that await clarification. Despite this, we attempt to provide an integrated view on the neural abnormalities that may contribute to various forms of juvenile aggression and violence, and discuss research strategies that may help to provide a more profound understanding of these important issues in the future. PMID:19862349

  1. How Is Pain Influenced by Cognition? Neuroimaging Weighs In

    PubMed Central

    Wager, Tor D.; Atlas, Lauren Y.

    2014-01-01

    Neuroimaging can inform cognitive theories to the extent that particular patterns of brain activity are sensitively and specifically associated with particular types of cognitive processes. We illustrate the utility of neuroimaging data in one specific case: understanding cognitive influences on pain. We first argue that pain self-reports are often inadequate to fully characterize pain experience and the processes that underlie it. Then, we describe how neuroimaging measures have been used to corroborate the effects of psychological manipulations on pain by focusing on placebo treatments and demonstrating effects on the best available correlates of pain experience. In addition, using placebo analgesia as an example, we argue that brain evidence is useful for building psychological theories likely to yield valid and generalizable predictions, because biologically informed theories are grounded in the constraints inherent in the relevant physiological systems. Finally, we suggest that neuroimaging findings will become increasingly useful for constraining psychological inference as brain patterns diagnostic of particular types of mental events are identified and characterized. In our view, the relationships between biological findings and cognitive theory are empirically based and must develop through an iterative process of synthesis across studies, topics, and methods. PMID:24761154

  2. Delirium and hypovitaminosis D: neuroimaging findings.

    PubMed

    Bourgeois, James A; Hategan, Ana; Ford, Jennifer; Tisi, Daniel K; Xiong, Glen L

    2015-01-01

    The authors examined the frequency of neuroimaging findings of cortical atrophy and/or cerebrovascular disease in patients with delirium with hypovitaminosis D and normal vitamin D levels. Of 32 patients with delirium with hypovitaminosis D who were neuroimaged, 91.4% had neuroimaging findings, despite only five cases having a comorbid diagnosis of dementia. Similar frequencies of cortical atrophy and/or cerebrovascular disease were found in patients with delirium with normal vitamin D levels. Further research with a larger sample size is needed to compare neuroimaging findings between normal patients and patients with hypovitaminosis D with delirium. PMID:25111282

  3. Electric field driven fractal growth in polymer electrolyte composites: Experimental evidence of theoretical simulations

    NASA Astrophysics Data System (ADS)

    Dawar, Anit; Chandra, Amita

    2012-11-01

    The influence of electric field on the diffusion limited aggregation has been observed experimentally. The observation provides experimental confirmation of the theoretical model proposed by Zhi-Jie Tan et al. [Phys. Lett. A 268 (2000) 112]. Most strikingly, a transition from a disordered ramified pattern to an ordered pattern (chain-like growth) has been observed. The growth is governed by diffusion, convection and migration in an electric field which give rise to the different patterns. This Letter can also be considered as an experimental evidence of computer simulated fractal growth given by Huang and Hibbert [Physica A 233 (1996) 888].

  4. Neuroimaging Week: A Novel, Engaging, and Effective Curriculum for Teaching Neuroimaging to Junior Psychiatric Residents

    ERIC Educational Resources Information Center

    Downar, Jonathan; Krizova, Adriana; Ghaffar, Omar; Zaretsky, Ari

    2010-01-01

    Objective: Neuroimaging techniques are increasingly important in psychiatric research and clinical practice, but few postgraduate psychiatry programs offer formal training in neuroimaging. To address this need, the authors developed a course to prepare psychiatric residents to use neuroimaging techniques effectively in independent practice.…

  5. Tinnitus: perspectives from human neuroimaging.

    PubMed

    Elgoyhen, Ana Belén; Langguth, Berthold; De Ridder, Dirk; Vanneste, Sven

    2015-10-01

    Tinnitus is the perception of phantom sound in the absence of a corresponding external source. It is a highly prevalent disorder, and most cases are caused by cochlear injury that leads to peripheral deafferentation, which results in adaptive changes in the CNS. In this article we critically assess the recent neuroimaging studies in individuals with tinnitus that suggest that the disorder is accompanied by functional and structural brain abnormalities in distributed auditory and non-auditory brain regions. Moreover, we consider how the identification of the neuronal mechanisms underlying the different forms of tinnitus would benefit from larger studies, replication and comprehensive clinical assessment of patients. PMID:26373470

  6. Neuroimaging of scoliosis in childhood.

    PubMed

    Kim, F M; Poussaint, T Y; Barnes, P D

    1999-02-01

    A curvature abnormality may be the initial or major presenting feature in a child with disease of the spinal column or spinal neuraxis. A simplified classification of common spinal curvature abnormalities of childhood include idiopathic, congenital/dysraphic, skeletal dysplasia, neurofibromatosis, and painful. The great majority of childhood scoliosis falls into the idiopathic category. Atypical clinical or radiographic features in a presumed idiopathic scoliosis may indicate an otherwise occult tumor or hydrosyringomyelia, or may be a consequence of increasing curvature with disk protrusion, nerve impingement, or cord attenuation. Neuroimaging beyond plain films is commonly necessary for atypical idiopathic scoliosis and for the other categories of scoliosis listed. PMID:9974506

  7. Evidence for deterministic chaos as the origin of electrical tree breakdown structures in polymeric insulation

    NASA Astrophysics Data System (ADS)

    Dodd, S. J.; Dissado, L. A.; Champion, J. V.; Alison, J. M.

    1995-12-01

    Electrical discharges were measured during the propagation stage of electrical tree breakdown in an epoxy resin. An analysis of their number sequence provides strong evidence for the existence of an underlying deterministic chaotic mechanism. The fractal dimension of the tree and that of the reconstructed attractor and Lyapunov exponent were found to be related. The higher fractal dimension tree (dt~1.9) is associated with an attractor dimension df~3.1 and Lyapunov exponent λ~0.008 bit/s. The lower fractal dimension tree (dt~1.5) is associated with values of df~3.56 and λ~0.028 bit/s. No evidence for the presence of random stochastic processes, an essential ingredient of the dielectric breakdown model, has been found.

  8. Neuroimaging.

    PubMed

    Pope, Whitney B; Djoukhadar, Ibrahim; Jackson, Alan

    2016-01-01

    Imaging is integral to the management of patients with brain tumors. Conventional structural imaging provides exquisite anatomic detail but remains limited in the evaluation of molecular characteristics of intracranial neoplasms. Quantitative and physiologic biomarkers derived from advanced imaging techniques have been increasingly utilized as problem-solving tools to identify glioma grade and assess response to therapy. This chapter provides a comprehensive overview of the imaging strategies used in the clinical assessment of patients with gliomas and describes how novel imaging biomarkers have the potential to improve patient management. PMID:26948347

  9. Neuroimaging of Freezing of Gait

    PubMed Central

    Fasano, Alfonso; Herman, Talia; Tessitore, Alessandro; Strafella, Antonio P.; Bohnen, Nicolaas I.

    2015-01-01

    Abstract Functional brain imaging techniques appear ideally suited to explore the pathophysiology of freezing of gait (FOG). In the last two decades, techniques based on magnetic resonance or nuclear medicine imaging have found a number of structural changes and functional disconnections between subcortical and cortical regions of the locomotor network in patients with FOG. FOG seems to be related in part to disruptions in the “executive-attention” network along with regional tissue loss including the premotor area, inferior frontal gyrus, precentral gyrus, the parietal and occipital areas involved in visuospatial functions of the right hemisphere. Several subcortical structures have been also involved in the etiology of FOG, principally the caudate nucleus and the locomotor centers in the brainstem. Maladaptive neural compensation may present transiently in the presence of acute conflicting motor, cognitive or emotional stimulus processing, thus causing acute network overload and resulting in episodic impairment of stepping. In this review we will summarize the state of the art of neuroimaging research for FOG. We will also discuss the limitations of current approaches and delineate the next steps of neuroimaging research to unravel the pathophysiology of this mysterious motor phenomenon. PMID:25757831

  10. What's new in neuroimaging methods?

    PubMed Central

    Bandettini, Peter A.

    2009-01-01

    The rapid advancement of neuroimaging methodology and availability has transformed neuroscience research. The answers to many questions that we ask about how the brain is organized depend on the quality of data that we are able to obtain about the locations, dynamics, fluctuations, magnitudes, and types of brain activity and structural changes. In this review, an attempt is made to take a snapshot of the cutting edge of a small component of the very rapidly evolving field of neuroimaging. For each area covered, a brief context is provided along with a summary of a few of the current developments and issues. Then, several outstanding papers, published in the past year or so, are described, providing an example of the directions in which each area is progressing. The areas covered include functional MRI (fMRI), voxel based morphometry (VBM), diffusion tensor imaging (DTI), electroencephalography (EEG), magnetoencephalography (MEG), optical imaging, and positron emission tomography (PET). More detail is included on fMRI, as subsections include: functional MRI interpretation, new functional MRI contrasts, MRI technology, MRI paradigms and processing, and endogenous oscillations in functional MRI. PMID:19338512

  11. Neuroimaging in repetitive brain trauma

    PubMed Central

    2014-01-01

    Sports-related concussions are one of the major causes of mild traumatic brain injury. Although most patients recover completely within days to weeks, those who experience repetitive brain trauma (RBT) may be at risk for developing a condition known as chronic traumatic encephalopathy (CTE). While this condition is most commonly observed in athletes who experience repetitive concussive and/or subconcussive blows to the head, such as boxers, football players, or hockey players, CTE may also affect soldiers on active duty. Currently, the only means by which to diagnose CTE is by the presence of phosphorylated tau aggregations post-mortem. Non-invasive neuroimaging, however, may allow early diagnosis as well as improve our understanding of the underlying pathophysiology of RBT. The purpose of this article is to review advanced neuroimaging methods used to investigate RBT, including diffusion tensor imaging, magnetic resonance spectroscopy, functional magnetic resonance imaging, susceptibility weighted imaging, and positron emission tomography. While there is a considerable literature using these methods in brain injury in general, the focus of this review is on RBT and those subject populations currently known to be susceptible to RBT, namely athletes and soldiers. Further, while direct detection of CTE in vivo has not yet been achieved, all of the methods described in this review provide insight into RBT and will likely lead to a better characterization (diagnosis), in vivo, of CTE than measures of self-report. PMID:25031630

  12. Smoking and Neuroimaging: A Review

    PubMed Central

    Kober, Hedy; DeLeone, Cameron M.

    2013-01-01

    Cigarette smoking is a significant public health concern, often resulting in nicotine dependence, a chronic-relapsing psychiatric diagnosis that is responsible for up to 10% of the global cardiovascular disease burden. Due to its significantly deleterious effects on health, much research has been dedicated to elucidating the underlying neurobiology of smoking. This brief article is intended to provide a digestible synopsis of the considerable research being conducted on the underlying neural bases of cigarette smoking and nicotine dependence, especially for cardiologists who are often at the front lines of treating nicotine dependence. To this end, we first review some of the most common neuroimaging methodologies used in the study of smoking, as well as the most recent findings from this exciting area of research. Then, we focus on several fundamental topics including the acute pharmacological effects, acute neurocognitive effects, and the long-term neurobiological effects associated with smoking. We finally review recent findings regarding the neuropsychological processes associated with smoking cessation, including cue-induced craving and regulation of craving. Research in this field beginning to uncover how some of these neuropsychological processes are similar across clinical disorders which cardiologists also encounter frequently, such as craving for food resulting in overeating. We conclude with recommendations for future neuroimaging work on these topics. PMID:24432182

  13. [Network analyses in neuroimaging studies].

    PubMed

    Hirano, Shigeki; Yamada, Makiko

    2013-06-01

    Neurons are anatomically and physiologically connected to each other, and these connections are involved in various neuronal functions. Multiple important neural networks involved in neurodegenerative diseases can be detected using network analyses in functional neuroimaging. First, the basic methods and theories of voxel-based network analyses, such as principal component analysis, independent component analysis, and seed-based analysis, are described. Disease- and symptom-specific brain networks have been identified using glucose metabolism images in patients with Parkinson's disease. These networks enable us to objectively evaluate individual patients and serve as diagnostic tools as well as biomarkers for therapeutic interventions. Many functional MRI studies have shown that "hub" brain regions, such as the posterior cingulate cortex and medial prefrontal cortex, are deactivated by externally driven cognitive tasks; such brain regions form the "default mode network." Recent studies have shown that this default mode network is disrupted from the preclinical phase of Alzheimer's disease and is associated with amyloid deposition in the brain. Some recent studies have shown that the default mode network is also impaired in Parkinson's disease, whereas other studies have shown inconsistent results. These incongruent results could be due to the heterogeneous pharmacological status, differences in mesocortical dopaminergic impairment status, and concomitant amyloid deposition. Future neuroimaging network analysis studies will reveal novel and interesting findings that will uncover the pathomechanisms of neurological and psychiatric disorders. PMID:23735528

  14. Neuroimaging of Cognitive Load in Instructional Multimedia

    ERIC Educational Resources Information Center

    Whelan, Robert R.

    2007-01-01

    This paper reviews research literature on cognitive load measurement in learning and neuroimaging, and describes a mapping between the main elements of cognitive load theory and findings in functional neuroanatomy. It is argued that these findings may lead to the improved measurement of cognitive load using neuroimaging. The paper describes how…

  15. Neuroimaging and Research into Second Language Acquisition

    ERIC Educational Resources Information Center

    Sabourin, Laura

    2009-01-01

    Neuroimaging techniques are becoming not only more and more sophisticated but are also coming to be increasingly accessible to researchers. One thing that one should take note of is the potential of neuroimaging research within second language acquisition (SLA) to contribute to issues pertaining to the plasticity of the adult brain and to general…

  16. FAST Observations of Acceleration Processes in the Cusp--Evidence for Parallel Electric Fields

    NASA Technical Reports Server (NTRS)

    Pfaff, R. F.. Jr.; Carlson, C.; McFadden, J.; Ergun, R.; Clemmons, J.; Klumpar D.; Strangeway, R.

    1999-01-01

    The existence of precipitating keV ions in the Earth's cusp originating at the magnetosheath provide unique means to test our understanding of particle acceleration and parallel electric fields in the lower altitude acceleration region. On numerous occasions, the FAST (The Fast Auroral Snapshot) spacecraft has encountered the Earth's cusp regions near its apogee of 4175 km which are characterized by their signatures of dispersed keV ion injections. The FAST instruments also reveal a complex microphysics inherent to many, but not all, of the cusp regions encountered by the spacecraft, that include upgoing ion beams and conics, inverted-V electrons, upgoing electron beams, and spikey DC-coupled electric fields and plasma waves. Detailed inspection of the FAST data often show clear modulation of the precipitating magnetosheath ions that indicate that they are affected by local electric potentials. For example, the magnetosheath ion precipitation is sometimes abruptly shut off precisely in regions where downgoing localized inverted-V electrons are observed. Such observations support the existence of a localized process, such as parallel electric fields, above the spacecraft which accelerate the electrons downward and consequently impede the precipitating ion precipitation. Other acceleration events in the cusp are sometimes organized with an apparent cellular structure that suggests Alfven waves or other large-scale phenomena are controlling the localized potentials. We examine several cusp encounters by the FAST satellite where the modulation of energetic session on acceleration particle populations reveals evidence of localized acceleration, most likely by parallel electric fields.

  17. Mechanisms underlying sporadic cerebral small vessel disease: insights from neuroimaging

    PubMed Central

    Wardlaw, JM; Smith, C; Dichgans, M

    2013-01-01

    The term “cerebral small vessel disease” (SVD) describes a range of neuroimaging, pathological and associated clinical features. The latter range from none, to discrete focal neurological symptoms (stroke), to insidious global neurological dysfunction and dementia. The public health burden is considerable. The pathogenesis is largely unknown. Although associated with vascular risk factors, and generally considered to result from an intrinsic cerebral arteriolar occlusive disease, the pathological processes leading to the arteriolar disease, how these result in brain disease, how SVD lesions contribute to neurological or cognitive symptoms and the relationship to risk factors, have been the subject of much speculation. Pathology often reflects end-stage disease making determination of the earliest stages difficult. Neuroimaging provides considerable insights: the small vessels are not easily seen themselves, but the effects of their malfunction on the brain can be tracked on detailed brain imaging. We review the growing evidence for the most likely mechanisms. PMID:23602162

  18. Worldwide Alzheimer's disease neuroimaging initiative.

    PubMed

    Carrillo, Maria C; Bain, Lisa J; Frisoni, Giovanni B; Weiner, Michael W

    2012-07-01

    The Alzheimer's Disease Neuroimaging Initiative (ADNI) was launched in 2003 to speed drug development by validating imaging and blood/cerebrospinal fluid biomarkers for Alzheimer's disease clinical treatment trials. ADNI is a naturalistic (nontreatment) multisite longitudinal study. A true public-private partnership, the first phase of ADNI (ADNI 1) set a new standard for data sharing without embargo. In addition, it has been extended to 2017 by additional funding (North American-ADNI Grand Opportunities and ADNI 2) as well as multiple projects around the world, collectively known as Worldwide ADNI (WW-ADNI). The goal of WW-ADNI is to harmonize projects and results across different geographical sites and to encourage and harmonize data management and availability to investigators around the world. WW-ADNI projects are currently underway in North America, Europe, Japan, Australia, Korea, Taiwan, and Argentina, with a nascent program in China and a possible future program in Brazil. PMID:22748939

  19. Integrating Genetic, Psychopharmacological and Neuroimaging Studies: A Converging Methods Approach to Understanding the Neurobiology of ADHD

    ERIC Educational Resources Information Center

    Durston, Sarah; Konrad, Kerstin

    2007-01-01

    This paper aims to illustrate how combining multiple approaches can inform us about the neurobiology of ADHD. Converging evidence from genetic, psychopharmacological and functional neuroimaging studies has implicated dopaminergic fronto-striatal circuitry in ADHD. However, while the observation of converging evidence from multiple vantage points…

  20. Direct Evidence for Daily Plasticity of Electrical Coupling between Rod Photoreceptors in the Mammalian Retina

    PubMed Central

    Jin, Nan Ge

    2016-01-01

    Rod photoreceptors are electrically coupled through gap junctions. Coupling is a key determinant of their light response properties, but whether rod electrical coupling is dynamically regulated remains elusive and controversial. Here, we have obtained direct measurements of the conductance between adjacent rods in mouse retina and present evidence that rod electrical coupling strength is dependent on the time of day, the lighting conditions, and the mouse strain. Specifically, we show in CBA/Ca mice that under circadian conditions, the rod junctional conductance has a median value of 98 pS during the subjective day and of 493 pS during the subjective night. In C57BL/6 mice, the median junctional conductance between dark-adapted rods is ∼140 pS, regardless of the time in the circadian cycle. Adaptation to bright light decreases the rod junctional conductance to ∼0 pS, regardless of the time of day or the mouse strain. Together, these results establish the high degree of plasticity of rod electrical coupling over the course of the day. Estimates of the rod coupling strength will provide a foundation for further investigations of rod interactions and the role of rod coupling in the ability of the visual system to anticipate, assimilate, and respond to the daily changes in ambient light intensity. SIGNIFICANCE STATEMENT Many cells in the CNS communicate via gap junctions, or electrical synapses, the regulation of which remains largely unknown. Here, we show that the strength of electrical coupling between rod photoreceptors of the retina is regulated by the time of day and the lighting conditions. This mechanism may help us understand some key aspects of day and night vision as well as some visual malfunctions. PMID:26740659

  1. Neuroimaging studies of word reading

    PubMed Central

    Fiez, Julie A.; Petersen, Steven E.

    1998-01-01

    This review discusses how neuroimaging can contribute to our understanding of a fundamental aspect of skilled reading: the ability to pronounce a visually presented word. One contribution of neuroimaging is that it provides a tool for localizing brain regions that are active during word reading. To assess the extent to which similar results are obtained across studies, a quantitative review of nine neuroimaging investigations of word reading was conducted. Across these studies, the results converge to reveal a set of areas active during word reading, including left-lateralized regions in occipital and occipitotemporal cortex, the left frontal operculum, bilateral regions within the cerebellum, primary motor cortex, and the superior and middle temporal cortex, and medial regions in the supplementary motor area and anterior cingulate. Beyond localization, the challenge is to use neuroimaging as a tool for understanding how reading is accomplished. Central to this challenge will be the integration of neuroimaging results with information from other methodologies. To illustrate this point, this review will highlight the importance of spelling-to-sound consistency in the transformation from orthographic (word form) to phonological (word sound) representations, and then explore results from three neuroimaging studies in which the spelling-to-sound consistency of the stimuli was deliberately varied. Emphasis is placed on the pattern of activation observed within the left frontal cortex, because the results provide an example of the issues and benefits involved in relating neuroimaging results to behavioral results in normal and brain damaged subjects, and to theoretical models of reading. PMID:9448259

  2. Defining the neurocircuitry of borderline personality disorder: functional neuroimaging approaches.

    PubMed

    Brendel, Gary R; Stern, Emily; Silbersweig, David A

    2005-01-01

    Functional neuroimaging recently has been used to localize brain dysfunction in borderline personality disorder (BPD). Initial studies have examined baseline activity or emotional reactivity, and our group has investigated what we consider to be a crucial interaction between negative emotion and behavioral (dys)control. This research is beginning to identify abnormal frontolimbic circuitry likely underlying core clinical features of this condition. We review the evidence for dysfunction in specific frontolimbic regions, leading to a mechanistic model of symptom formation in BPD. In addition, we offer an integration of these neuroimaging findings with developmental perspectives on the emergence of borderline psychopathology, focusing on the ways in which early psychosocial experience may interact with developing brain systems. We also consider possible mechanisms of psychotherapeutic change at the neural systems level in BPD. Finally, we propose that future neuroimaging studies of BPD should integrate multiple levels of observation (structural, functional, neurochemical, genetic, and clinical) in a model-driven fashion to further understand the dynamic relationship between biological and psychological factors in the development and treatment of this difficult condition. PMID:16613437

  3. Neurochemistry of schizophrenia: the contribution of neuroimaging postmortem pathology and neurochemistry in schizophrenia.

    PubMed

    Dean, B

    2012-01-01

    The advent of molecular neuroimaging has greatly impacted on understanding the neurochemical changes occurring in the CNS from subjects with psychiatric disorders, especially schizophrenia. This review focuses on the outcomes from studies using positron emission tomography and single photon emission computer tomography that have measure levels of neurotransmitter receptors and transporters in the CNS from subjects with schizophrenia. One outcome from such studies is the confirmation of a number of findings using postmortem tissue, but in the case of neuroimaging, using drug na�ve and drug free subjects. These findings add weight to the argument that findings from postmortem studies are not an artifact of tissue processing or a simple drug effect. However, there are some important unique findings from studies using neuroimaging studies. These include evidence to suggest that in schizophrenia there are alterations in dopamine synthesis and release, which are not accompanied by an appropriate down-regulation of dopamine D2 receptors. There are also data that would support the notion that decreased levels of serotonin 2A receptors may be an early marker of the onset of schizophrenia. Whilst there is a clear need for on-going development of neuroimaging ligands to expand the number of targets that can be studied and to increase cohort sizes in neuroimaging studies to give power to the analyses of the resulting data, current studies show that existing neuroimaging studies have already extended our understanding of the underlying pathophysiology of psychiatric disorders such as schizophrenia. PMID:23279177

  4. Neuroimaging Biomarkers of Neurodegenerative Diseases and Dementia

    PubMed Central

    Risacher, Shannon L.; Saykin, Andrew J.

    2014-01-01

    Neurodegenerative disorders leading to dementia are common diseases that affect many older and some young adults. Neuroimaging methods are important tools for assessing and monitoring pathological brain changes associated with progressive neurodegenerative conditions. In this review, the authors describe key findings from neuroimaging studies (magnetic resonance imaging and radionucleotide imaging) in neurodegenerative disorders, including Alzheimer’s disease (AD) and prodromal stages, familial and atypical AD syndromes, frontotemporal dementia, amyotrophic lateral sclerosis with and without dementia, Parkinson’s disease with and without dementia, dementia with Lewy bodies, Huntington’s disease, multiple sclerosis, HIV-associated neurocognitive disorder, and prion protein associated diseases (i.e., Creutzfeldt-Jakob disease). The authors focus on neuroimaging findings of in vivo pathology in these disorders, as well as the potential for neuroimaging to provide useful information for differential diagnosis of neurodegenerative disorders. PMID:24234359

  5. Neuroimaging of the Philadelphia Neurodevelopmental Cohort

    PubMed Central

    Satterthwaite, Theodore D.; Elliott, Mark A.; Ruparel, Kosha; Loughead, James; Prabhakaran, Karthik; Calkins, Monica E.; Hopson, Ryan; Jackson, Chad; Keefe, Jack; Riley, Marisa; Mensh, Frank D.; Sleiman, Patrick; Verma, Ragini; Davatzikos, Christos; Hakonarson, Hakon; Gur, Ruben C.; Gur, Raquel E.

    2013-01-01

    The Philadelphia Neurodevelopmental Cohort (PNC) is a large-scale, NIMH funded initiative to understand how brain maturation mediates cognitive development and vulnerability to psychiatric illness, and understand how genetics impacts this process. As part of this study, 1,445 adolescents ages 8–21 at enrollment underwent multimodal neuroimaging. Here, we highlight the conceptual basis for the effort, the study design, and measures available in the dataset. We focus on neuroimaging measures obtained, including T1-weighted structural neuroimaging, diffusion tensor imaging, perfusion neuroimaging using arterial spin labeling, functional imaging tasks of working memory and emotion identification, and resting state imaging of functional connectivity. Furthermore, we provide characteristics regarding the final sample acquired. Finally, we describe mechanisms in place for data sharing that will allow the PNC to become a freely available public resource to advance our understanding of normal and pathological brain development. PMID:23921101

  6. Structural and electric evidence of ferrielectric state in Pb₂MnWO₆ double perovskite system.

    PubMed

    Orlandi, Fabio; Righi, Lara; Cabassi, Riccardo; Delmonte, Davide; Pernechele, Chiara; Bolzoni, Fulvio; Mezzadri, Francesco; Solzi, Massimo; Merlini, Marco; Calestani, Gianluca

    2014-10-01

    In this paper we describe the new ferri-electric compound Pb2MnWO6 (PMW), a double perovskite that can be considered as a novel structural prototype showing complex nuclear structure and interesting electric properties. According to single-crystal synchrotron data, PMW crystallizes in the noncentrosymmetric polar group Pmc21, in which the two symmetry-independent lead atoms give rise to a ferrielectric arrangement. The accurate crystallographic characterization indicates the presence of a complex distortion of the perovskite lattice driven by the local instability induced by the 6s(2) lone pair of the lead atoms. These peculiar structural features are confirmed by the complete electrical characterization of the system. Dielectric and transport measurements indicate an insulating character of the sample, while pyroelectric measurements point out a ferrielectric state characterized by different contributions. The magnetic transition at 45 K is accompanied by a magnetostrictive effect indicating a probable spin-lattice coupling. The characterizations carried out on PMW, showing the evidence of a coexistence of antiferromagnetism and ferrielectricity at low temperature, could lead to the definition of a new class of multiferroic materials. PMID:25197959

  7. Developments in functional neuroimaging techniques

    SciTech Connect

    Aine, C.J.

    1995-03-01

    A recent review of neuroimaging techniques indicates that new developments have primarily occurred in the area of data acquisition hardware/software technology. For example, new pulse sequences on standard clinical imagers and high-powered, rapidly oscillating magnetic field gradients used in echo planar imaging (EPI) have advanced MRI into the functional imaging arena. Significant developments in tomograph design have also been achieved for monitoring the distribution of positron-emitting radioactive tracers in the body (PET). Detector sizes, which pose a limit on spatial resolution, have become smaller (e.g., 3--5 mm wide) and a new emphasis on volumetric imaging has emerged which affords greater sensitivity for determining locations of positron annihilations and permits smaller doses to be utilized. Electromagnetic techniques have also witnessed growth in the ability to acquire data from the whole head simultaneously. EEG techniques have increased their electrode coverage (e.g., 128 channels rather than 16 or 32) and new whole-head systems are now in use for MEG. But the real challenge now is in the design and implementation of more sophisticated analyses to effectively handle the tremendous amount of physiological/anatomical data that can be acquired. Furthermore, such analyses will be necessary for integrating data across techniques in order to provide a truly comprehensive understanding of the functional organization of the human brain.

  8. Neuroimaging of schizophrenia: structural abnormalities and pathophysiological implications

    PubMed Central

    Buckley, Peter F

    2005-01-01

    Schizophrenia, once considered a psychological malady devoid of any organic brain substrate, has been the focus of intense neuroimaging research. Findings reveal mild but generalized tissue loss as well as more selective focal loss. It is unclear whether these abnormalities reflect neurodevelopmental or neurodegenerative processes, or some combination of each; current evidence favors a preponderance of neurodevelopmental abnormalities. The pattern of brain abnormalities is also influenced by environmental and genetic risk factors, as well as by the course (and possibly even treatment) of this illness. These findings are described in this article. PMID:18568069

  9. Neuroimaging of Central Sensitivity Syndromes: Key Insights from the Scientific Literature.

    PubMed

    Walitt, Brian; Ceko, Marta; Gracely, John L; Gracely, Richard H

    2016-01-01

    Central sensitivity syndromes are characterized by distressing symptoms, such as pain and fatigue, in the absence of clinically obvious pathology. The scientific underpinnings of these disorders are not currently known. Modern neuroimaging techniques promise new insights into mechanisms mediating these postulated syndromes. We review the results of neuroimaging applied to five central sensitivity syndromes: fibromyalgia, chronic fatigue syndrome, irritable bowel syndrome, temporomandibular joint disorder, and vulvodynia syndrome. Neuroimaging studies of basal metabolism, anatomic constitution, molecular constituents, evoked neural activity, and treatment effect are compared across all of these syndromes. Evoked sensory paradigms reveal sensory augmentation to both painful and nonpainful stimulation. This is a transformative observation for these syndromes, which were historically considered to be completely of hysterical or feigned in origin. However, whether sensory augmentation represents the cause of these syndromes, a predisposing factor, an endophenotype, or an epiphenomenon cannot be discerned from the current literature. Further, the result from cross-sectional neuroimaging studies of basal activity, anatomy, and molecular constituency are extremely heterogeneous within and between the syndromes. A defining neuroimaging "signature" cannot be discerned for any of the particular syndromes or for an over-arching central sensitization mechanism common to all of the syndromes. Several issues confound initial attempts to meaningfully measure treatment effects in these syndromes. At this time, the existence of "central sensitivity syndromes" is based more soundly on clinical and epidemiological evidence. A coherent picture of a "central sensitization" mechanism that bridges across all of these syndromes does not emerge from the existing scientific evidence. PMID:26717948

  10. Molecular neuroimaging in degenerative dementias.

    PubMed

    Jiménez Bonilla, J F; Carril Carril, J M

    2013-01-01

    In the context of the limitations of structural imaging, brain perfusion and metabolism using SPECT and PET have provided relevant information for the study of cognitive decline. The introduction of the radiotracers for cerebral amyloid imaging has changed the diagnostic strategy regarding Alzheimer's disease, which is currently considered to be a "continuum." According to this new paradigm, the increasing amyloid load would be associated to the preclinical phase and mild cognitive impairment. It has been possible to observe "in vivo" images using 11C-PIB and PET scans. The characteristics of the 11C-PIB image include specific high brain cortical area retention in the positive cases with typical distribution pattern and no retention in the negative cases. This, in combination with 18F-FDG PET, is the basis of molecular neuroimaging as a biomarker. At present, its prognostic value is being evaluated in longitudinal studies. 11C-PIB-PET has become the reference radiotracer to evaluate the presence of cerebral amyloid. However, its availability is limited due to the need for a nearby cyclotron. Therefore, 18F labeled radiotracers are being introduced. Our experience in the last two years with 11C-PIB, first in the research phase and then as being clinically applied, has shown the utility of the technique in the clinical field, either alone or in combination with FDG. Thus, amyloid image is a useful tool for the differential diagnosis of dementia and it is a potentially useful method for early diagnosis and evaluation of future treatments. PMID:23933381

  11. Evidence for parallel electric field particle acceleration in the dayside auroral oval

    NASA Technical Reports Server (NTRS)

    Torbert, R. B.; Carlson, C. W.

    1980-01-01

    Electron and ion energy spectra and electron pitch angle distributions are presented for two sounding rocket flights in the dayside auroral zone. At times, effects of dc electric fields parallel to the magnetic field are evident in that: (1) within precipitation features, protons are decelerated by an amount of energy consistent with that which electrons gain and (2) electrons are sometimes aligned to within 3 deg (full width at half maximum) of the magnetic field. A maximum altitude for the accelerating region of several thousand kilometers is deduced from the narrow width of the pitch angle distribution and also from time-of-flight delays between the observation of accelerated electrons and decelerated protons.

  12. Functional Electrical Stimulation in Spinal Cord Injury: Clinical Evidence Versus Daily Practice.

    PubMed

    Bersch, Ines; Tesini, Stefani; Bersch, Ulf; Frotzler, Angela

    2015-10-01

    Functional electrical stimulation (FES) has clinical evidence in the rehabilitation of patients with spinal cord injury as indicated by several studies. Both inpatients and outpatients benefit from the therapeutic effect of the FES. The application areas are multifaceted and can be customized on the need for patients. This is represented by the individuality of the programmability of the stimulators and the variety of stimulation schedules that are based on the knowledge about the effects of FES on structural and functional level. Nevertheless, looking into daily clinical practice, the use of FES is rather poor. Expenditure of time, complexity of technical equipment, and compliance and acceptance of therapists and patients should be taken into account as limiting factors. PMID:26471135

  13. Miniaturized optical neuroimaging in unrestrained animals.

    PubMed

    Yu, Hang; Senarathna, Janaka; Tyler, Betty M; Thakor, Nitish V; Pathak, Arvind P

    2015-06-01

    The confluence of technological advances in optics, miniaturized electronic components and the availability of ever increasing and affordable computational power have ushered in a new era in functional neuroimaging, namely, an era in which neuroimaging of cortical function in unrestrained and unanesthetized rodents has become a reality. Traditional optical neuroimaging required animals to be anesthetized and restrained. This greatly limited the kinds of experiments that could be performed in vivo. Now one can assess blood flow and oxygenation changes resulting from functional activity and image functional response in disease models such as stroke and seizure, and even conduct long-term imaging of tumor physiology, all without the confounding effects of anesthetics or animal restraints. These advances are shedding new light on mammalian brain organization and function, and helping to elucidate loss of this organization or 'dysfunction' in a wide array of central nervous system disease models. In this review, we highlight recent advances in the fabrication, characterization and application of miniaturized head-mounted optical neuroimaging systems pioneered by innovative investigators from a wide array of disciplines. We broadly classify these systems into those based on exogenous contrast agents, such as single- and two-photon microscopy systems; and those based on endogenous contrast mechanisms, such as multispectral or laser speckle contrast imaging systems. Finally, we conclude with a discussion of the strengths and weaknesses of these approaches along with a perspective on the future of this exciting new frontier in neuroimaging. PMID:25791782

  14. Does social approval stimulate prosocial behavior? Evidence from a field experiment in the residential electricity market

    NASA Astrophysics Data System (ADS)

    Yoeli, Erez

    At least since Veblen (1899), economists have proposed that people do good because they desire "social approval" and want to look good in front of others. Evidence from the laboratory supports this claim, but is difficult to generalize due to the unrealistic degree of scrutiny in a laboratory environment. I administer a field experiment to test the potency of social approval in a realistic and policy relevant setting. In the experiment I solicit 7893 customers of a large electric utility for a program that helps prevent blackouts. I vary whether their decision to participate in the program is revealed to their neighbors. Customers whose decision is revealed are 1.5% more likely to sign up than those whose decision is anonymous when their decision is framed as a contribution to a public good. Social approval increases participation more than offering subjects a $25 incentive, and its effect is large relative to the mean sign-up rate of 4.1%. I explore whether social approval contributes to crowding out and conditionally cooperative behavior, but the evidence is inconclusive.

  15. Prenatal Cerebellar Disruptions: Neuroimaging Spectrum of Findings in Correlation with Likely Mechanisms and Etiologies of Injury.

    PubMed

    Poretti, Andrea; Boltshauser, Eugen; Huisman, Thierry A G M

    2016-08-01

    There is increasing evidence that the cerebellum is susceptible to prenatal infections and hemorrhages and that congenital morphologic anomalies of the cerebellum may be caused by disruptive (acquired) causes. Starting from the neuroimaging pattern, this report describes a spectrum of prenatal cerebellar disruptions including cerebellar agenesis, unilateral cerebellar hypoplasia, cerebellar cleft, global cerebellar hypoplasia, and vanishing cerebellum in Chiari type II malformation. The neuroimaging findings, possible causative disruptive events, and clinical features of each disruption are discussed. Recognition of cerebellar disruptions and their differentiation from cerebellar malformations is important in terms of diagnosis, prognosis, and genetic counselling. PMID:27423799

  16. Neuroimaging auditory hallucinations in schizophrenia: from neuroanatomy to neurochemistry and beyond.

    PubMed

    Allen, Paul; Modinos, Gemma; Hubl, Daniela; Shields, Gregory; Cachia, Arnaud; Jardri, Renaud; Thomas, Pierre; Woodward, Todd; Shotbolt, Paul; Plaze, Marion; Hoffman, Ralph

    2012-06-01

    Despite more than 2 decades of neuroimaging investigations, there is currently insufficient evidence to fully understand the neurobiological substrate of auditory hallucinations (AH). However, some progress has been made with imaging studies in patients with AH consistently reporting altered structure and function in speech and language, sensory, and nonsensory regions. This report provides an update of neuroimaging studies of AH with a particular emphasis on more recent anatomical, physiological, and neurochemical imaging studies. Specifically, we provide (1) a review of findings in schizophrenia and nonschizophrenia voice hearers, (2) a discussion regarding key issues that have interfered with progress, and (3) practical recommendations for future studies. PMID:22535906

  17. Neuroimaging Auditory Hallucinations in Schizophrenia: From Neuroanatomy to Neurochemistry and Beyond

    PubMed Central

    Allen, Paul; Modinos, Gemma; Hubl, Daniela; Shields, Gregory; Cachia, Arnaud; Jardri, Renaud; Thomas, Pierre; Woodward, Todd; Shotbolt, Paul; Plaze, Marion; Hoffman, Ralph

    2012-01-01

    Despite more than 2 decades of neuroimaging investigations, there is currently insufficient evidence to fully understand the neurobiological substrate of auditory hallucinations (AH). However, some progress has been made with imaging studies in patients with AH consistently reporting altered structure and function in speech and language, sensory, and nonsensory regions. This report provides an update of neuroimaging studies of AH with a particular emphasis on more recent anatomical, physiological, and neurochemical imaging studies. Specifically, we provide (1) a review of findings in schizophrenia and nonschizophrenia voice hearers, (2) a discussion regarding key issues that have interfered with progress, and (3) practical recommendations for future studies. PMID:22535906

  18. Neuroimaging in moderate MDMA use: A systematic review.

    PubMed

    Mueller, F; Lenz, C; Steiner, M; Dolder, P C; Walter, M; Lang, U E; Liechti, M E; Borgwardt, S

    2016-03-01

    MDMA ("ecstasy") is widely used as a recreational drug, although there has been some debate about its neurotoxic effects in humans. However, most studies have investigated subjects with heavy use patterns, and the effects of transient MDMA use are unclear. In this review, we therefore focus on subjects with moderate use patterns, in order to assess the evidence for harmful effects. We searched for studies applying neuroimaging techniques in man. Studies were included if they provided at least one group with an average of <50 lifetime episodes of ecstasy use or an average lifetime consumption of <100 ecstasy tablets. All studies published before July 2015 were included. Of the 250 studies identified in the database search, 19 were included. There is no convincing evidence that moderate MDMA use is associated with structural or functional brain alterations in neuroimaging measures. The lack of significant results was associated with high methodological heterogeneity in terms of dosages and co-consumption of other drugs, low quality of studies and small sample sizes. PMID:26746590

  19. Methodological Approaches in Developmental Neuroimaging Studies

    PubMed Central

    Luna, Beatriz; Velanova, Katerina; Geier, Charles F.

    2010-01-01

    Pediatric neuroimaging is increasingly providing insights into the neural basis of cognitive development. Indeed, we have now arrived at a stage where we can begin to identify optimal methodological and statistical approaches to the acquisition and analysis of developmental imaging data. In this article, we describe a number of these approaches and how their selection impacts the ability to examine and interpret developmental effects. We describe preferred approaches to task selection, definition of age groups, selection of fMRI designs, definition of regions of interest (ROI), optimal baseline measures, and treatment of timecourse data. Consideration of these aspects of developmental neuroimaging reveals that unlike single-group neuroimaging studies, developmental studies pose unique challenges that impact study planning, task design, data analysis, and the interpretation of findings. PMID:20496377

  20. Neuroimaging Coordination Dynamics in the Sport Sciences

    PubMed Central

    Jantzen, Kelly J.; Oullier, Olivier; Kelso, J.A. Scott

    2008-01-01

    Key methodological issues for designing, analyzing, and interpreting neuroimaging experiments are presented from the perspective of the framework of Coordination Dynamics. To this end, a brief overview of Coordination Dynamics is introduced, including the main concepts of control parameters and collective variables, theoretical modeling, novel experimental paradigms, and cardinal empirical findings. Basic conceptual and methodological issues for the design and implementation of coordination experiments in the context of neuroimaging are discussed. The paper concludes with a presentation of neuroimaging findings central to understanding the neural basis of coordination and addresses their relevance for the sport sciences. The latter include but are not restricted to learning and practice-related issues, the role of mental imagery, and the recovery of function following brain injury. PMID:18602998

  1. Activity-dependent plasticity of electrical synapses: increasing evidence for its presence and functional roles in the mammalian brain.

    PubMed

    Haas, Julie S; Greenwald, Corey M; Pereda, Alberto E

    2016-01-01

    Gap junctions mediate electrical synaptic transmission between neurons. While the actions of neurotransmitter modulators on the conductance of gap junctions have been extensively documented, increasing evidence indicates they can also be influenced by the ongoing activity of neural networks, in most cases via local interactions with nearby glutamatergic synapses. We review here early evidence for the existence of activity-dependent regulatory mechanisms as well recent examples reported in mammalian brain. The ubiquitous distribution of both neuronal connexins and the molecules involved suggest this phenomenon is widespread and represents a property of electrical transmission in general. PMID:27230776

  2. Verb generation in patients with focal frontal lesions: A neuropsychological test of neuroimaging findings

    PubMed Central

    Thompson-Schill, Sharon L.; Swick, Diane; Farah, Martha J.; D’Esposito, Mark; Kan, Irene P.; Knight, Robert T.

    1998-01-01

    What are the neural bases of semantic memory? Traditional beliefs that the temporal lobes subserve the retrieval of semantic knowledge, arising from lesion studies, have been recently called into question by functional neuroimaging studies finding correlations between semantic retrieval and activity in left prefrontal cortex. Has neuroimaging taught us something new about the neural bases of cognition that older methods could not reveal or has it merely identified brain activity that is correlated with but not causally related to the process of semantic retrieval? We examined the ability of patients with focal frontal lesions to perform a task commonly used in neuroimaging experiments, the generation of semantically appropriate action words for concrete nouns, and found evidence of the necessity of the left inferior frontal gyrus for certain components of the verb generation task. Notably, these components did not include semantic retrieval per se. PMID:9861060

  3. Graphical Neuroimaging Informatics: Application to Alzheimer’s Disease

    PubMed Central

    Bowman, Ian; Joshi, Shantanu H.; Greer, Vaughan

    2013-01-01

    The Informatics Visualization for Neuroimaging (INVIZIAN) framework allows one to graphically display image and meta-data information from sizeable collections of neuroimaging data as a whole using a dynamic and compelling user interface. Users can fluidly interact with an entire collection of cortical surfaces using only their mouse. In addition, users can cluster and group brains according in multiple ways for subsequent comparison using graphical data mining tools. In this article, we illustrate the utility of INVIZIAN for simultaneous exploration and mining a large collection of extracted cortical surface data arising in clinical neuroimaging studies of patients with Alzheimer’s Disease, mild cognitive impairment, as well as healthy control subjects. Alzheimer’s Disease is particularly interesting due to the wide-spread effects on cortical architecture and alterations of volume in specific brain areas associated with memory. We demonstrate INVIZIAN’s ability to render multiple brain surfaces from multiple diagnostic groups of subjects, showcase the interactivity of the system, and showcase how INVIZIAN can be employed to generate hypotheses about the collection of data which would be suitable for direct access to the underlying raw data and subsequent formal statistical analysis. Specifically, we use INVIZIAN show how cortical thickness and hippocampal volume differences between group are evident even in the absence of more formal hypothesis testing. In the context of neurological diseases linked to brain aging such as AD, INVIZIAN provides a unique means for considering the entirety of whole brain datasets, look for interesting relationships among them, and thereby derive new ideas for further research and study. PMID:24203652

  4. Structural neuroimaging in schizophrenia from methods to insights to treatments

    PubMed Central

    Shenton, Martha E.; Whitford, Thomas J.; Kubicki, Marek

    2010-01-01

    Historically, Kraepelin speculated that dementia praecox resulted from damage to the cerebral cortex, most notably the frontal and temporal cortices. It is only recently, however, that tools have been available to test this hypothesis. Now, more than a century later, we know that schizophrenia is a brain disorder. This knowledge comes from critical advances in imaging technology- including computerized axial tomography, magnetic resonance imaging, and diffusion imaging - all of which provide an unprecedented view of neuroanatomical structures, in vivo. Here, we review evidence for structural neuroimaging abnormalities, beginning with evidence for focal brain abnormalities, primarily in gray matter, and proceeding to the quest to identify abnormalities in brain systems and circuits by focusing on damage to white matter connections in the brain. We then review future prospects that need to be explored and pursued in order to translate our current knowledge into an understanding of the neurobiology of schizophrenia, which can then be translated into novel treatments. PMID:20954428

  5. Structural neuroimaging in schizophrenia: from methods to insights to treatments.

    PubMed

    Shenton, Martha E; Whitford, Thomas J; Kubicki, Marek

    2010-01-01

    Historically, Kraepelin speculated that dementia praecox resulted from damage to the cerebral cortex, most notably the frontal and temporal cortices. It is only recently, however, that tools have been available to test this hypothesis. Now, more than a century later, we know that schizophrenia is a brain disorder. This knowledge comes from critical advances in imaging technology--including computerized axial tomography, magnetic resonance imaging, and diffusion imaging--all of which provide an unprecedented view of neuroanatomical structures, in vivo. Here, we review evidence for structural neuroimaging abnormalities, beginning with evidence for focal brain abnormalities, primarily in gray matter, and proceeding to the quest to identify abnormalities in brain systems and circuits by focusing on damage to white matter connections in the brain. We then review future prospects that need to be explored and pursued in order to translate our current knowledge into an understanding of the neurobiology of schizophrenia, which can then be translated into novel treatments. PMID:20954428

  6. Electrical Stimulation and Cutaneous Wound Healing: A Review of Clinical Evidence

    PubMed Central

    Ud-Din, Sara; Bayat, Ardeshir

    2014-01-01

    Electrical stimulation (ES) has been shown to have beneficial effects in wound healing. It is important to assess the effects of ES on cutaneous wound healing in order to ensure optimization for clinical practice. Several different applications as well as modalities of ES have been described, including direct current (DC), alternating current (AC), high-voltage pulsed current (HVPC), low-intensity direct current (LIDC) and electrobiofeedback ES. However, no one method has been advocated as the most optimal for the treatment of cutaneous wound healing. Therefore, this review aims to examine the level of evidence (LOE) for the application of different types of ES to enhance cutaneous wound healing in the skin. An extensive search was conducted to identify relevant clinical studies utilising ES for cutaneous wound healing since 1980 using PubMed, Medline and EMBASE. A total of 48 studies were evaluated and assigned LOE. All types of ES demonstrated positive effects on cutaneous wound healing in the majority of studies. However, the reported studies demonstrate contrasting differences in the parameters and types of ES application, leading to an inability to generate sufficient evidence to support any one standard therapeutic approach. Despite variations in the type of current, duration, and dosing of ES, the majority of studies showed a significant improvement in wound area reduction or accelerated wound healing compared to the standard of care or sham therapy as well as improved local perfusion. The limited number of LOE-1 trials for investigating the effects of ES in wound healing make critical evaluation and assessment somewhat difficult. Further, better-designed clinical trials are needed to improve our understanding of the optimal dosing, timing and type of ES to be used.

  7. Neuroimaging in childhood headache: a systematic review.

    PubMed

    Alexiou, George A; Argyropoulou, Maria I

    2013-07-01

    Headache is a common complaint in children, one that gives rise to considerable parental concern and fear of the presence of a space-occupying lesion. The evaluation and diagnosis of headache is very challenging for paediatricians, and neuroimaging by means of CT or MRI is often requested as part of the investigation. CT exposes children to radiation, while MRI is costly and sometimes requires sedation or general anaesthesia, especially in children younger than 6 years. This review of the literature on the value of neuroimaging in children with headache showed that the rate of pathological findings is generally low. Imaging findings that led to a change in patient management were in almost all cases reported in children with abnormal signs on neurological examination. Neuroimaging should be limited to children with a suspicious clinical history, abnormal neurological findings or other physical signs suggestive of intracranial pathology. Well-designed prospective studies are needed to better define the clinical findings that warrant neuroimaging in children with headache. PMID:23700196

  8. Functional neuroimaging: technical, logical, and social perspectives.

    PubMed

    Aguirre, Geoffrey K

    2014-01-01

    Neuroscientists have long sought to study the dynamic activity of the human brain-what's happening in the brain, that is, while people are thinking, feeling, and acting. Ideally, an inside look at brain function would simultaneously and continuously measure the biochemical state of every cell in the central nervous system. While such a miraculous method is science fiction, a century of progress in neuroimaging technologies has made such simultaneous and continuous measurement a plausible fiction. Despite this progress, practitioners of modern neuroimaging struggle with two kinds of limitations: those that attend the particular neuroimaging methods we have today and those that would limit any method of imaging neural activity, no matter how powerful. In this essay, I consider the liabilities and potential of techniques that measure human brain activity. I am concerned here only with methods that measure relevant physiologic states of the central nervous system and relate those measures to particular mental states. I will consider in particular the preeminent method of functional neuroimaging: BOLD fMRI. While there are several practical limits on the biological information that current technologies can measure, these limits-as important as they are-are minor in comparison to the fundamental logical restraints on the conclusions that can be drawn from brain imaging studies. PMID:24634086

  9. Functional Neuroimaging Studies of Written Sentence Comprehension

    ERIC Educational Resources Information Center

    Caplan, David

    2004-01-01

    Sentences convey relationships between the meanings of words, such as who is accomplishing an action or receiving it. Functional neuroimaging based on positron-emission tomography and functional magnetic resonance imaging has been used to identify areas of the brain involved in structuring sentences and determining aspects of meaning associated…

  10. Neuroimaging and Fetal Alcohol Spectrum Disorders

    ERIC Educational Resources Information Center

    Norman, Andria L.; Crocker, Nicole; Mattson, Sarah N.; Riley, Edward P.

    2009-01-01

    The detrimental effects of prenatal alcohol exposure on the developing brain include structural brain anomalies as well as cognitive and behavioral deficits. Initial neuroimaging studies of fetal alcohol spectrum disorders (FASD) using magnetic resonance imaging (MRI) confirmed previous autopsy reports of overall reduction in brain volume and…

  11. Neuroimaging studies of social cognition in schizophrenia.

    PubMed

    Fujiwara, Hironobu; Yassin, Walid; Murai, Toshiya

    2015-05-01

    Impaired social cognition is considered a core contributor to unfavorable psychosocial functioning in schizophrenia. Rather than being a unitary process, social cognition is a collection of multifaceted processes that recruit multiple brain structures, thus structural and functional neuroimaging techniques are ideal methodologies for revealing the underlying pathophysiology of impaired social cognition. Many neuroimaging studies have suggested that in addition to white-matter deficits, schizophrenia is associated with decreased gray-matter volume in multiple brain areas, especially fronto-temporal and limbic regions. However, few schizophrenia studies have examined associations between brain abnormalities and social cognitive disabilities. During the last decade, we have investigated structural brain abnormalities in schizophrenia using high-resolution magnetic resonance imaging, and our findings have been confirmed by us and others. By assessing different types of social cognitive abilities, structural abnormalities in multiple brain regions have been found to be associated with disabilities in social cognition, such as recognition of facial emotion, theory of mind, and empathy. These structural deficits have also been associated with alexithymia and quality of life in ways that are closely related to the social cognitive disabilities found in schizophrenia. Here, we overview a series of neuroimaging studies from our laboratory that exemplify current research into this topic, and discuss how it can be further tackled using recent advances in neuroimaging technology. PMID:25418865

  12. Neuroimaging of Mobility in Aging: A Targeted Review

    PubMed Central

    Epstein, Noah; Mahoney, Jeannette R.; Izzetoglu, Meltem; Blumen, Helena M.

    2014-01-01

    Background. The relationship between mobility and cognition in aging is well established, but the relationship between mobility and the structure and function of the aging brain is relatively unknown. This, in part, is attributed to the technological limitations of most neuroimaging procedures, which require the individual to be immobile or in a supine position. Herein, we provide a targeted review of neuroimaging studies of mobility in aging to promote (i) a better understanding of this relationship, (ii) future research in this area, and (iii) development of applications for improving mobility. Methods. A systematic search of peer-reviewed studies was performed using PubMed. Search terms included (i) aging, older adults, or elderly; (ii) gait, walking, balance, or mobility; and (iii) magnetic resonance imaging, voxel-based morphometry, fluid-attenuated inversion recovery, diffusion tensor imaging, positron emission tomography, functional magnetic resonance imaging, electroencephalography, event-related potential, and functional near-infrared spectroscopy. Results. Poor mobility outcomes were reliably associated with reduced gray and white matter volume. Fewer studies examined the relationship between changes in task-related brain activation and mobility performance. Extant findings, however, showed that activation patterns in the cerebellum, basal ganglia, parietal and frontal cortices were related to mobility. Increased involvement of the prefrontal cortex was evident in both imagined walking conditions and conditions where the cognitive demands of locomotion were increased. Conclusions. Cortical control of gait in aging is bilateral, widespread, and dependent on the integrity of both gray and white matter. PMID:24739495

  13. Neuroimaging of amblyopia and binocular vision: a review

    PubMed Central

    Joly, Olivier; Frankó, Edit

    2014-01-01

    Amblyopia is a cerebral visual impairment considered to derive from abnormal visual experience (e.g., strabismus, anisometropia). Amblyopia, first considered as a monocular disorder, is now often seen as a primarily binocular disorder resulting in more and more studies examining the binocular deficits in the patients. The neural mechanisms of amblyopia are not completely understood even though they have been investigated with electrophysiological recordings in animal models and more recently with neuroimaging techniques in humans. In this review, we summarize the current knowledge about the brain regions that underlie the visual deficits associated with amblyopia with a focus on binocular vision using functional magnetic resonance imaging. The first studies focused on abnormal responses in the primary and secondary visual areas whereas recent evidence shows that there are also deficits at higher levels of the visual pathways within the parieto-occipital and temporal cortices. These higher level areas are part of the cortical network involved in 3D vision from binocular cues. Therefore, reduced responses in these areas could be related to the impaired binocular vision in amblyopic patients. Promising new binocular treatments might at least partially correct the activation in these areas. Future neuroimaging experiments could help to characterize the brain response changes associated with these treatments and help devise them. PMID:25147511

  14. Structural neuroimaging in Altheimer's disease: do white matter hyperintensities matter?

    PubMed

    Brickman, Adam M; Muraskin, Jordan; Zimmerman, Molly E

    2009-01-01

    The targeted brain dysfunction that accompanies aging can have a devastating effect on cognitive and intellectual abilities. A significant proportion of older adults experience precipitous cognitive decline that negatively impacts functional activities. Such individuals meet clinical diagnostic criteria for dementia, which is commonly attributed to Alzheimer's disease (AD). Structural neuroimaging, including magnetic resonance imaging (MRI), has contributed significantly to our understanding of the morphological and pathology-related changes that may underlie normal and disease-associated cognitive change in aging. White matter hyperintensities (WMH), which are distributed patches of increased hyperintense signal on T2-weighted MRI, are among the most common structural neuroimaging findings in older adults. In recent years, WMH have emerged as robust radiological correlates of cognitive decline. Studies suggest that WMH distributed in anterior brain regions are related to decline in executive abilities that is typical of normal aging, whereas WMH distributed in more posterior brain regions are common in AD. Although epidemiological, observational, and pathological studies suggest that WMH may be ischemic in origin and caused by consistent or variable hypoperfusion, there is emerging evidence that they may also reflect vascular deposition of beta-amyloid, particularly when they are distributed in posterior areas and are present in patients with AD. Findings from the literature highlight the potential contribution of small-vessel cerebrovascular disease to the pathogenesis of AD, and suggest a mechanistic interaction, but future longitudinal studies using multiple imaging modalities are required to fully understand the complex role of WMH in AD. PMID:19585953

  15. Evidence that dirty electricity is causing the worldwide epidemics of obesity and diabetes.

    PubMed

    Milham, Samuel

    2014-01-01

    The epidemics of obesity and diabetes most apparent in recent years had their origins with Thomas Edison's development of distributed electricity in New York City in 1882. His original direct current (DC) generators suffered serious commutator brush arcing which is a major source of high-frequency voltage transients (dirty electricity). From the onset of the electrical grid, electrified populations have been exposed to dirty electricity. Diesel generator sets are a major source of dirty electricity today and are used almost universally to electrify small islands and places unreachable by the conventional electric grid. This accounts for the fact that diabetes prevalence, fasting plasma glucose and obesity are highest on small islands and other places electrified by generator sets and lowest in places with low levels of electrification like sub-Saharan Africa and east and Southeast Asia. PMID:23781992

  16. Deep learning for neuroimaging: a validation study.

    PubMed

    Plis, Sergey M; Hjelm, Devon R; Salakhutdinov, Ruslan; Allen, Elena A; Bockholt, Henry J; Long, Jeffrey D; Johnson, Hans J; Paulsen, Jane S; Turner, Jessica A; Calhoun, Vince D

    2014-01-01

    Deep learning methods have recently made notable advances in the tasks of classification and representation learning. These tasks are important for brain imaging and neuroscience discovery, making the methods attractive for porting to a neuroimager's toolbox. Success of these methods is, in part, explained by the flexibility of deep learning models. However, this flexibility makes the process of porting to new areas a difficult parameter optimization problem. In this work we demonstrate our results (and feasible parameter ranges) in application of deep learning methods to structural and functional brain imaging data. These methods include deep belief networks and their building block the restricted Boltzmann machine. We also describe a novel constraint-based approach to visualizing high dimensional data. We use it to analyze the effect of parameter choices on data transformations. Our results show that deep learning methods are able to learn physiologically important representations and detect latent relations in neuroimaging data. PMID:25191215

  17. Deep learning for neuroimaging: a validation study

    PubMed Central

    Plis, Sergey M.; Hjelm, Devon R.; Salakhutdinov, Ruslan; Allen, Elena A.; Bockholt, Henry J.; Long, Jeffrey D.; Johnson, Hans J.; Paulsen, Jane S.; Turner, Jessica A.; Calhoun, Vince D.

    2014-01-01

    Deep learning methods have recently made notable advances in the tasks of classification and representation learning. These tasks are important for brain imaging and neuroscience discovery, making the methods attractive for porting to a neuroimager's toolbox. Success of these methods is, in part, explained by the flexibility of deep learning models. However, this flexibility makes the process of porting to new areas a difficult parameter optimization problem. In this work we demonstrate our results (and feasible parameter ranges) in application of deep learning methods to structural and functional brain imaging data. These methods include deep belief networks and their building block the restricted Boltzmann machine. We also describe a novel constraint-based approach to visualizing high dimensional data. We use it to analyze the effect of parameter choices on data transformations. Our results show that deep learning methods are able to learn physiologically important representations and detect latent relations in neuroimaging data. PMID:25191215

  18. Fetal Alcohol Spectrum Disorders: Recent Neuroimaging Findings.

    PubMed

    Moore, Eileen M; Migliorini, Robyn; Infante, M Alejandra; Riley, Edward P

    2014-09-01

    Since the identification of Fetal Alcohol Syndrome over 40 years ago, much has been learned about the detrimental effects of prenatal alcohol exposure on the developing brain. This review highlights recent neuroimaging studies, within the context of previous work. Structural magnetic resonance imaging has described morphological differences in the brain and their relationships to cognitive deficits and measures of facial dysmorphology. Diffusion tensor imaging has elaborated on the relationship between white matter microstructure and behavior. Atypical neuromaturation across childhood and adolescence has been observed in longitudinal neuroimaging studies. Functional imaging has revealed differences in neural activation patterns underlying sensory processing, cognition and behavioral deficits. A recent functional connectivity analysis demonstrates reductions in global network efficiency. Despite this progress much remains unknown about the impact of prenatal alcohol exposure on the brain, and continued research efforts are essential. PMID:25346882

  19. Causal interpretation rules for encoding and decoding models in neuroimaging.

    PubMed

    Weichwald, Sebastian; Meyer, Timm; Özdenizci, Ozan; Schölkopf, Bernhard; Ball, Tonio; Grosse-Wentrup, Moritz

    2015-04-15

    Causal terminology is often introduced in the interpretation of encoding and decoding models trained on neuroimaging data. In this article, we investigate which causal statements are warranted and which ones are not supported by empirical evidence. We argue that the distinction between encoding and decoding models is not sufficient for this purpose: relevant features in encoding and decoding models carry a different meaning in stimulus- and in response-based experimental paradigms.We show that only encoding models in the stimulus-based setting support unambiguous causal interpretations. By combining encoding and decoding models trained on the same data, however, we obtain insights into causal relations beyond those that are implied by each individual model type. We illustrate the empirical relevance of our theoretical findings on EEG data recorded during a visuo-motor learning task. PMID:25623501

  20. Neuroimaging in human MDMA (Ecstasy) users.

    PubMed

    Cowan, Ronald L; Roberts, Deanne M; Joers, James M

    2008-10-01

    MDMA (3,4 methylenedioxymethamphetamine) has been used by millions of people worldwide as a recreational drug. The terms "MDMA" and "Ecstasy" are often used synonymously, but it is important to note that the purity of Ecstasy sold as MDMA is not certain. MDMA use is of public health concern, not so much because MDMA produces a common or severe dependence syndrome, but rather because rodent and nonhuman primate studies have indicated that MDMA (when administered at certain dosages and intervals) can cause long-lasting reductions in markers of brain serotonin (5-HT) that appear specific to fine-diameter axons arising largely from the dorsal raphe nucleus (DR). Given the popularity of MDMA, the potential for the drug to produce long-lasting or permanent 5-HT axon damage or loss, and the widespread role of 5-HT function in the brain, there is a great need for a better understanding of brain function in human users of this drug. To this end, neuropsychological, neuroendocrine, and neuroimaging studies have all suggested that human MDMA users may have long-lasting changes in brain function consistent with 5-HT toxicity. Data from animal models leads to testable hypotheses regarding MDMA's effects on the human brain. Because neuropsychological and neuroimaging findings have focused on the neocortex, a cortical model is developed to provide a context for designing and interpreting neuroimaging studies in MDMA users. Aspects of the model are supported by the available neuroimaging data, but there are controversial findings in some areas and most findings have not been replicated across different laboratories and using different modalities. This paper reviews existing findings in the context of a cortical model and suggests directions for future research. PMID:18991874

  1. Testable Hypotheses for Unbalanced Neuroimaging Data

    PubMed Central

    McFarquhar, Martyn

    2016-01-01

    Unbalanced group-level models are common in neuroimaging. Typically, data for these models come from factorial experiments. As such, analyses typically take the form of an analysis of variance (ANOVA) within the framework of the general linear model (GLM). Although ANOVA theory is well established for the balanced case, in unbalanced designs there are multiple ways of decomposing the sums-of-squares of the data. This leads to several methods of forming test statistics when the model contains multiple factors and interactions. Although the Type I–III sums of squares have a long history of debate in the statistical literature, there has seemingly been no consideration of this aspect of the GLM in neuroimaging. In this paper we present an exposition of these different forms of hypotheses for the neuroimaging researcher, discussing their derivation as estimable functions of ANOVA models, and discussing the relative merits of each. Finally, we demonstrate how the different hypothesis tests can be implemented using contrasts in analysis software, presenting examples in SPM and FSL. PMID:27378839

  2. Traumatic brain injury, neuroimaging, and neurodegeneration

    PubMed Central

    Bigler, Erin D.

    2012-01-01

    Depending on severity, traumatic brain injury (TBI) induces immediate neuropathological effects that in the mildest form may be transient but as severity increases results in neural damage and degeneration. The first phase of neural degeneration is explainable by the primary acute and secondary neuropathological effects initiated by the injury; however, neuroimaging studies demonstrate a prolonged period of pathological changes that progressively occur even during the chronic phase. This review examines how neuroimaging may be used in TBI to understand (1) the dynamic changes that occur in brain development relevant to understanding the effects of TBI and how these relate to developmental stage when the brain is injured, (2) how TBI interferes with age-typical brain development and the effects of aging thereafter, and (3) how TBI results in greater frontotemporolimbic damage, results in cerebral atrophy, and is more disruptive to white matter neural connectivity. Neuroimaging quantification in TBI demonstrates degenerative effects from brain injury over time. An adverse synergistic influence of TBI with aging may predispose the brain injured individual for the development of neuropsychiatric and neurodegenerative disorders long after surviving the brain injury. PMID:23964217

  3. [Neuroimaging of psychiatric and pedopsychiatric disorders].

    PubMed

    Martinot, Jean-Luc; Mana, Stéphanie

    2011-01-01

    Over the last two decades, imaging techniques have allowed to establish the cerebral neurophysiologic correlates of psychiatric disorders and have highlighted the impact of psychopathologic events, therapeutic drugs, addictions, on the growth and plasticity of brain. In this review, we intend to illustrate how neuroimaging has improved our knowledge of such alterations in brain maturation (schizophrenia, autistic disorders), fronto-limbic (depressive syndromes) or fronto-striatal (compulsive disorders) regions in psychiatric illnesses, but also in psychopharmacology, or pedopsychiatry. Statistically significant alterations in the structure and/or function of brain are detected in all psychiatric disorders and these are often detectable already during childhood or teenage. Furthermore, neuroimaging has allowed to underline the importance of cerebral networks specific to each disorder, but also to uncover those which are common to different diseases provided that they share common clinical or cognitive features. Besides their value in basic research, neuroimaging findings have been key in changing the perception that society has of these diseases which contributed to their therapeutic approach. PMID:21718649

  4. Advanced Neuroimaging in Traumatic Brain Injury

    PubMed Central

    Edlow, Brian L.; Wu, Ona

    2013-01-01

    Advances in structural and functional neuroimaging have occurred at a rapid pace over the past two decades. Novel techniques for measuring cerebral blood flow, metabolism, white matter connectivity, and neural network activation have great potential to improve the accuracy of diagnosis and prognosis for patients with traumatic brain injury (TBI), while also providing biomarkers to guide the development of new therapies. Several of these advanced imaging modalities are currently being implemented into clinical practice, whereas others require further development and validation. Ultimately, for advanced neuroimaging techniques to reach their full potential and improve clinical care for the many civilians and military personnel affected by TBI, it is critical for clinicians to understand the applications and methodological limitations of each technique. In this review, we examine recent advances in structural and functional neuroimaging and the potential applications of these techniques to the clinical care of patients with TBI. We also discuss pitfalls and confounders that should be considered when interpreting data from each technique. Finally, given the vast amounts of advanced imaging data that will soon be available to clinicians, we discuss strategies for optimizing data integration, visualization and interpretation. PMID:23361483

  5. Neuroimaging of Central Sensitivity Syndromes: Key Insights from the Scientific Literature

    PubMed Central

    Walitt, Brian; Čeko, Marta; Gracely, John L.; Gracely, Richard H.

    2016-01-01

    Central sensitivity syndromes are characterized by distressing symptoms, such as pain and fatigue, in the absence of clinically obvious pathology. The scientific underpinnings of these disorders are not currently known. Modern neuroimaging techniques promise new insights into mechanisms mediating these postulated syndromes. We review the results of neuroimaging applied to five central sensitivity syndromes: fibromyalgia, chronic fatigue syndrome, irritable bowel syndrome, temporomandibular joint disorder, and vulvodynia syndrome. Neuroimaging studies of basal metabolism, anatomic constitution, molecular constituents, evoked neural activity, and treatment effect are compared across all of these syndromes. Evoked sensory paradigms reveal sensory augmentation to both painful and non-painful stimulation. This is a transformative observation for these syndromes, which were historically considered to be completely of hysterical or feigned in origin. However, whether sensory augmentation represents the cause of these syndromes, a predisposing factor, an endophenotype, or an epiphenomenon cannot be discerned from the current literature. Further, the result from cross-sectional neuroimaging studies of basal activity, anatomy, and molecular constituency are extremely heterogeneous within and between the syndromes. A defining neuroimaging “signature” cannot be discerned for any of the particular syndromes or for an over-arching central sensitization mechanism common to all of the syndromes. Several issues confound initial attempts to meaningfully measure treatment effects in these syndromes. At this time, the existence of “central sensitivity syndromes” is based more soundly on clinical and epidemiological evidence. A coherent picture of a “central sensitization” mechanism that bridges across all of these syndromes does not emerge from the existing scientific evidence. PMID:26717948

  6. Neuropsychiatric deep brain stimulation for translational neuroimaging.

    PubMed

    Höflich, Anna; Savli, Markus; Comasco, Erika; Moser, Ulrike; Novak, Klaus; Kasper, Siegfried; Lanzenberger, Rupert

    2013-10-01

    From a neuroimaging point of view, deep brain stimulation (DBS) in psychiatric disorders represents a unique source of information to probe results gained in functional, structural and molecular neuroimaging studies in vivo. However, the implementation has, up to now, been restricted by the heterogeneity of the data reported in DBS studies. The aim of the present study was therefore to provide a comprehensive and standardized database of currently used DBS targets in selected psychiatric disorders (obsessive-compulsive disorder (OCD), treatment-resistant depression (TRD), Gilles de la Tourette syndrome (GTS)) to enable topological comparisons between neuroimaging results and stimulation areas. A systematic literature research was performed and all peer-reviewed publications until the year 2012 were included. Literature research yielded a total of 84 peer-reviewed studies including about 296 psychiatric patients. The individual stimulation data of 37 of these studies meeting the inclusion criteria which included a total of 202 patients (63 OCD, 89 TRD, 50 GTS) was translated into MNI stereotactic space with respect to AC origin in order to identify key targets. The created database can be used to compare DBS target areas in MNI stereotactic coordinates with: 1) activation patterns in functional brain imaging (fMRI, phfMRI, PET, MET, EEG); 2) brain connectivity data (e.g., MR-based DTI/tractography, functional and effective connectivity); 3) quantitative molecular distribution data (e.g., neuroreceptor PET, post-mortem neuroreceptor mapping); 4) structural data (e.g., VBM for neuroplastic changes). Vice versa, the structural, functional and molecular data may provide a rationale to define new DBS targets and adjust/fine-tune currently used targets in DBS based on this overview in stereotactic coordinates. Furthermore, the availability of DBS data in stereotactic space may facilitate the investigation and interpretation of treatment effects and side effect of DBS by

  7. Emerging neuroimaging contribution to the diagnosis and management of the ring chromosome 20 syndrome.

    PubMed

    Vaudano, Anna Elisabetta; Ruggieri, Andrea; Vignoli, Aglaia; Canevini, Maria Paola; Meletti, Stefano

    2015-04-01

    Ring chromosome 20 [r(20)] syndrome is an underdiagnosed chromosomal anomaly characterized by severe epilepsy, behavioral problems, and mild-to-moderate cognitive deficits. Since the cognitive and behavioral decline follows seizure onset, this syndrome has been proposed as an epileptic encephalopathy (EE). The recent overwhelming development of advanced neuroimaging techniques has opened a new era in the investigation of the brain networks subserving the EEs. In particular, functional neuroimaging tools are well suited to show alterations related to epileptiform discharges at the network level and to build hypotheses about the mechanisms underlying the cognitive disruption observed in these conditions. This paper reviews the brain circuits and their disruption as revealed by functional neuroimaging studies in patients with [r(20)] syndrome. It discusses the clinical consequences of the neuroimaging findings on the management of patients with [r(20)] syndrome, including their impact to an earlier diagnosis of this disorder. Based on the available lines of evidences, [r(20)] syndrome is characterized by interictal and ictal dysfunctions within basal ganglia-prefrontal lobe networks and by long-lasting effects of the peculiar theta-delta rhythm, which represents an EEG marker of the syndrome on integrated brain networks that subserve cognitive functions. PMID:25843339

  8. Cultured Construction: Global Evidence of the Impact of National Values on Renewable Electricity Infrastructure Choice.

    PubMed

    Kaminsky, Jessica A

    2016-02-16

    Renewable electricity is an important tool in the fight against climate change, but globally these technologies are still in the early stages of diffusion. To contribute to our understanding of the factors driving this diffusion, I study relationships between national values (measured by Hofstede's cultural dimensions) and renewable electricity adoption at the national level. Existing data for 66 nations (representing an equal number of developed and developing economies) are used to fuel the analysis. Somewhat dependent on limited available data on controls for grid reliability and the cost of electricity, I discover that three of Hofstede's dimensions (high uncertainty avoidance, low masculinity-femininity, and high individualism-collectivism) have significant exponential relationships with renewable electricity adoption. The dimension of uncertainty avoidance appears particularly appropriate for practical application. Projects or organizations implementing renewable electricity policy, designs, or construction should particularly attend to this cultural dimension. In particular, as the data imply that renewable technologies are being used to manage risk in electricity supply, geographies with unreliable grids are particularly likely to be open to renewable electricity technologies. PMID:26735210

  9. “Can It Read My Mind?” – What Do the Public and Experts Think of the Current (Mis)Uses of Neuroimaging?

    PubMed Central

    Wardlaw, Joanna M.; O'Connell, Garret; Shuler, Kirsten; DeWilde, Janet; Haley, Jane; Escobar, Oliver; Murray, Shaun; Rae, Robert; Jarvie, Donald; Sandercock, Peter; Schafer, Burkhard

    2011-01-01

    Emerging applications of neuroimaging outside medicine and science have received intense public exposure through the media. Media misrepresentations can create a gulf between public and scientific understanding of the capabilities of neuroimaging and raise false expectations. To determine the extent of this effect and determine public opinions on acceptable uses and the need for regulation, we designed an electronic survey to obtain anonymous opinions from as wide a range of members of the public and neuroimaging experts as possible. The surveys ran from 1st June to 30 September 2010, asked 10 and 21 questions, respectively, about uses of neuroimaging outside traditional medical diagnosis, data storage, science communication and potential methods of regulation. We analysed the responses using descriptive statistics; 660 individuals responded to the public and 303 individuals responded to the expert survey. We found evidence of public skepticism about the use of neuroimaging for applications such as lie detection or to determine consumer preferences and considerable disquiet about use by employers or government and about how their data would be stored and used. While also somewhat skeptical about new applications of neuroimaging, experts grossly underestimated how often neuroimaging had been used as evidence in court. Although both the public and the experts rated highly the importance of a better informed public in limiting the inappropriate uses to which neuroimaging might be put, opinions differed on the need for, and mechanism of, actual regulation. Neuroscientists recognized the risks of inaccurate reporting of neuroimaging capabilities in the media but showed little motivation to engage with the public. The present study also emphasizes the need for better frameworks for scientific engagement with media and public education. PMID:21991367

  10. EVIDENCE FOR MICROBIAL ENHANCED ELECTRICAL CONDUCTIVITY IN HYDROCARBON-CONTAMINATED SEDIMENTS

    EPA Science Inventory

    Electrical conductivity of sediments during microbial mineralization of diesel was investigated in a mesoscale column experiment consisting of biotic contaminated and uncontaminated columns. Microbial population numbers increased with a clear pattern of depth zonation within the ...

  11. The Representation of Object Distance: Evidence from Neuroimaging and Neuropsychology

    PubMed Central

    Berryhill, Marian E.; Olson, Ingrid R.

    2009-01-01

    Perceived distance in two-dimensional (2D) images relies on monocular distance cues. Here, we examined the representation of perceived object distance using a continuous carry-over adaptation design for fMRI. The task was to look at photographs of objects and make a judgment as to whether or not the item belonged in the kitchen. Importantly, this task was orthogonal to the variable of interest: the object's perceived distance from the viewer. In Experiment 1, whole brain group analyses identified bilateral clusters in the superior occipital gyrus (approximately area V3/V3A) that showed parametric adaptation to relative changes in perceived distance. In Experiment 2, retinotopic analyses confirmed that area V3A/B reflected the greatest magnitude of response to monocular changes in perceived distance. In Experiment 3, we report that the functional activations overlap with the occipito-parietal lesions in a patient with impaired distance perception, showing that the same regions monitor implied (2D) and actual (three-dimensional) distance. These data suggest that distance information is automatically processed even when it is task-irrelevant and that this process relies on superior occipital areas in and around area V3A. PMID:19949468

  12. Medical-Legal Inferences From Functional Neuroimaging Evidence.

    PubMed

    Mayberg

    1996-07-01

    Positron emission (PET) and single-photon emission tomography (SPECT) are validated functional imaging techniques for the in vivo measurement of many neuro-phsyiological and neurochemical parameters. Research studies of patients with a broad range of neurological and psychiatric illness have been published. Reproducible and specific patterns of altered cerebral blood flow and glucose metabolism, however, have been demonstrated and confirmed for only a limited number of specific illnesses. The association of functional scan patterns with specific deficits is less conclusive. Correlations of regional abnormalities with clinical symptoms such as motor weakness, aphasia, and visual spatial dysfunction are the most reproducible but are more poorly localized than lesion-deficit studies would suggest. Findings are even less consistent for nonlocalizing behavioral symptoms such as memory difficulties, poor concentration, irritability, or chronic pain, and no reliable patterns have been demonstrated. In a forensic context, homicidal and sadistic tendencies, aberrant sexual drive, violent impulsivity, psychopathic and sociopathic personality traits, as well as impaired judgement and poor insight, have no known PET or SPECT patterns, and their presence in an individual with any PET or SPECT scan finding cannot be inferred or concluded. Furthermore, the reliable prediction of any specific neurological, psychiatric, or behavioral deficits from specific scan findings has not been demonstrated. Unambiguous results from experiments designed to specifically examine the causative relationships between regional brain dysfunction and these types of complex behaviors are needed before any introduction of functional scans into the courts can be considered scientifically justified or legally admissible. PMID:10320420

  13. Methods for identifying subject-specific abnormalities in neuroimaging data.

    PubMed

    Mayer, Andrew R; Bedrick, Edward J; Ling, Josef M; Toulouse, Trent; Dodd, Andrew

    2014-11-01

    Algorithms that are capable of capturing subject-specific abnormalities (SSA) in neuroimaging data have long been an area of focus for diverse neuropsychiatric conditions such as multiple sclerosis, schizophrenia, and traumatic brain injury. Several algorithms have been proposed that define SSA in patients (i.e., comparison group) relative to image intensity levels derived from healthy controls (HC) (i.e., reference group) based on extreme values. However, the assumptions underlying these approaches have not always been fully validated, and may be dependent on the statistical distributions of the transformed data. The current study evaluated variations of two commonly used techniques ("pothole" method and standardization with an independent reference group) for identifying SSA using simulated data (derived from normal, t and chi-square distributions) and fractional anisotropy maps derived from 50 HC. Results indicated substantial group-wise bias in the estimation of extreme data points using the pothole method, with the degree of bias being inversely related to sample size. Statistical theory was utilized to develop a distribution-corrected z-score (DisCo-Z) threshold, with additional simulations demonstrating elimination of the bias and a more consistent estimation of extremes based on expected distributional properties. Data from previously published studies examining SSA in mild traumatic brain injury were then re-analyzed using the DisCo-Z method, with results confirming the evidence of group-wise bias. We conclude that the benefits of identifying SSA in neuropsychiatric research are substantial, but that proposed SSA approaches require careful implementation under the different distributional properties that characterize neuroimaging data. PMID:24931496

  14. Advances in neuroimaging in frontotemporal dementia.

    PubMed

    Gordon, Elizabeth; Rohrer, Jonathan D; Fox, Nick C

    2016-08-01

    Frontotemporal dementia (FTD) is a clinically and neuroanatomically heterogeneous neurodegenerative disorder with multiple underlying genetic and pathological causes. Whilst initial neuroimaging studies highlighted the presence of frontal and temporal lobe atrophy or hypometabolism as the unifying feature in patients with FTD, more detailed studies have revealed diverse patterns across individuals, with variable frontal or temporal predominance, differing degrees of asymmetry, and the involvement of other cortical areas including the insula and cingulate, as well as subcortical structures such as the basal ganglia and thalamus. Recent advances in novel imaging modalities including diffusion tensor imaging, resting-state functional magnetic resonance imaging and molecular positron emission tomography imaging allow the possibility of investigating alterations in structural and functional connectivity and the visualisation of pathological protein deposition. This review will cover the major imaging modalities currently used in research and clinical practice, focusing on the key insights they have provided into FTD, including the onset and evolution of pathological changes and also importantly their utility as biomarkers for disease detection and staging, differential diagnosis and measurement of disease progression. Validating neuroimaging biomarkers that are able to accomplish these tasks will be crucial for the ultimate goal of powering upcoming clinical trials by correctly stratifying patient enrolment and providing sensitive markers for evaluating the effects and efficacy of disease-modifying therapies. This review describes the key insights provided by research into the major neuroimaging modalities currently used in research and clinical practice, including what they tell us about the onset and evolution of FTD and how they may be used as biomarkers for disease detection and staging, differential diagnosis and measurement of disease progression. This article is

  15. LSTGEE: longitudinal analysis of neuroimaging data

    NASA Astrophysics Data System (ADS)

    Li, Yimei; Zhu, Hongtu; Chen, Yasheng; An, Hongyu; Gilmore, John; Lin, Weili; Shen, Dinggang

    2009-02-01

    Longitudinal imaging studies are essential to understanding the neural development of neuropsychiatric disorders, substance use disorders, and normal brain. Using appropriate image processing and statistical tools to analyze the imaging, behavioral, and clinical data is critical for optimally exploring and interpreting the findings from those imaging studies. However, the existing imaging processing and statistical methods for analyzing imaging longitudinal measures are primarily developed for cross-sectional neuroimaging studies. The simple use of these cross-sectional tools to longitudinal imaging studies will significantly decrease the statistical power of longitudinal studies in detecting subtle changes of imaging measures and the causal role of time-dependent covariate in disease process. The main objective of this paper is to develop longitudinal statistics toolbox, called LSTGEE, for the analysis of neuroimaging data from longitudinal studies. We develop generalized estimating equations for jointly modeling imaging measures with behavioral and clinical variables from longitudinal studies. We develop a test procedure based on a score test statistic and a resampling method to test linear hypotheses of unknown parameters, such as associations between brain structure and function and covariates of interest, such as IQ, age, gene, diagnostic groups, and severity of disease. We demonstrate the application of our statistical methods to the detection of the changes of the fractional anisotropy across time in a longitudinal neonate study. Particularly, our results demonstrate that the use of longitudinal statistics can dramatically increase the statistical power in detecting the changes of neuroimaging measures. The proposed approach can be applied to longitudinal data with multiple outcomes and accommodate incomplete and unbalanced data, i.e., subjects with different number of measurements.

  16. REX: response exploration for neuroimaging datasets.

    PubMed

    Duff, Eugene P; Cunnington, Ross; Egan, Gary F

    2007-01-01

    Neuroimaging technologies produce large and complex datasets. The challenge of comprehensively analysing the recorded dynamics remains an important field of research. The whole-brain linear modelling of hypothesised response dynamics and experimental effects must utilise simple basis sets, which may not detect unexpected or complex signal effects. These unmodelled effects can influence statistical mapping results, and provide important additional clues to the underlying neural dynamics. They can be detected via exploration of the raw signal, however this can be difficult. Specialised visualisation tools are required to manage the huge number of voxels, events and scans. Many effects can be occluded by noise in individual voxel time-series. This paper describes a visualisation framework developed for the assessment of entire neuroimaging datasets. While currently available tools tend to be tied to a specific model of experimental effects, this framework includes a novel metadata schema that enables the rapid selection and processing of responses based on easily-adjusted classifications of scans, brain regions, and events. Flexible event-related averaging and process pipelining capabilities enable users to investigate the effects of preprocessing algorithms and to visualise power spectra and other transformations of the data. The framework has been implemented as a MATLAB package, REX (Response Exploration), which has been utilised within our lab and is now publicly available for download. Its interface enables the real-time control of data selection and processing, for very rapid visualisation. The concepts outlined in this paper have general applicability, and could provide significant further functionality to neuroimaging databasing and process pipeline environments. PMID:17985253

  17. Practical management of heterogeneous neuroimaging metadata by global neuroimaging data repositories.

    PubMed

    Neu, Scott C; Crawford, Karen L; Toga, Arthur W

    2012-01-01

    Rapidly evolving neuroimaging techniques are producing unprecedented quantities of digital data at the same time that many research studies are evolving into global, multi-disciplinary collaborations between geographically distributed scientists. While networked computers have made it almost trivial to transmit data across long distances, collecting and analyzing this data requires extensive metadata if the data is to be maximally shared. Though it is typically straightforward to encode text and numerical values into files and send content between different locations, it is often difficult to attach context and implicit assumptions to the content. As the number of and geographic separation between data contributors grows to national and global scales, the heterogeneity of the collected metadata increases and conformance to a single standardization becomes implausible. Neuroimaging data repositories must then not only accumulate data but must also consolidate disparate metadata into an integrated view. In this article, using specific examples from our experiences, we demonstrate how standardization alone cannot achieve full integration of neuroimaging data from multiple heterogeneous sources and why a fundamental change in the architecture of neuroimaging data repositories is needed instead. PMID:22470336

  18. Practical management of heterogeneous neuroimaging metadata by global neuroimaging data repositories

    PubMed Central

    Neu, Scott C.; Crawford, Karen L.; Toga, Arthur W.

    2012-01-01

    Rapidly evolving neuroimaging techniques are producing unprecedented quantities of digital data at the same time that many research studies are evolving into global, multi-disciplinary collaborations between geographically distributed scientists. While networked computers have made it almost trivial to transmit data across long distances, collecting and analyzing this data requires extensive metadata if the data is to be maximally shared. Though it is typically straightforward to encode text and numerical values into files and send content between different locations, it is often difficult to attach context and implicit assumptions to the content. As the number of and geographic separation between data contributors grows to national and global scales, the heterogeneity of the collected metadata increases and conformance to a single standardization becomes implausible. Neuroimaging data repositories must then not only accumulate data but must also consolidate disparate metadata into an integrated view. In this article, using specific examples from our experiences, we demonstrate how standardization alone cannot achieve full integration of neuroimaging data from multiple heterogeneous sources and why a fundamental change in the architecture of neuroimaging data repositories is needed instead. PMID:22470336

  19. The Extensible Neuroimaging Archive Toolkit: an informatics platform for managing, exploring, and sharing neuroimaging data.

    PubMed

    Marcus, Daniel S; Olsen, Timothy R; Ramaratnam, Mohana; Buckner, Randy L

    2007-01-01

    The Extensible Neuroimaging Archive Toolkit (XNAT) is a software platform designed to facilitate common management and productivity tasks for neuroimaging and associated data. In particular, XNAT enables qualitycontrol procedures and provides secure access to and storage of data. XNAT follows a threetiered architecture that includes a data archive, user interface, and middleware engine. Data can be entered into the archive as XML or through data entry forms. Newly added data are stored in a virtual quarantine until an authorized user has validated it. XNAT subsequently maintains a history profile to track all changes made to the managed data. User access to the archive is provided by a secure web application. The web application provides a number of quality control and productivity features, including data entry forms, data-type-specific searches, searches that combine across data types, detailed reports, and listings of experimental data, upload/download tools, access to standard laboratory workflows, and administration and security tools. XNAT also includes an online image viewer that supports a number of common neuroimaging formats, including DICOM and Analyze. The viewer can be extended to support additional formats and to generate custom displays. By managing data with XNAT, laboratories are prepared to better maintain the long-term integrity of their data, to explore emergent relations across data types, and to share their data with the broader neuroimaging community. PMID:17426351

  20. Neuroimaging for patient selection for medial temporal lobe epilepsy surgery: Part 1 Structural neuroimaging.

    PubMed

    Stylianou, Petros; Hoffmann, Chen; Blat, Ilan; Harnof, Sagi

    2016-01-01

    The objective of part one of this review is to present the structural neuroimaging techniques that are currently used to evaluate patients with temporal lobe epilepsy (TLE), and to discuss their potential to define patient eligibility for medial temporal lobe surgery. A PubMed query, using Medline and Embase, and subsequent review, was performed for all English language studies published after 1990, reporting neuroimaging methods for the evaluation of patients with TLE. The extracted data included demographic variables, population and study design, imaging methods, gold standard methods, imaging findings, surgical outcomes and conclusions. Overall, 56 papers were reviewed, including a total of 1517 patients. This review highlights the following structural neuroimaging techniques: MRI, diffusion-weighted imaging, tractography, electroencephalography and magnetoencephalography. The developments in neuroimaging during the last decades have led to remarkable improvements in surgical precision, postsurgical outcome, prognosis, and the rate of seizure control in patients with TLE. The use of multiple imaging methods provides improved outcomes, and further improvements will be possible with future studies of larger patient cohorts. PMID:26362835

  1. Computational neuroimaging and population receptive fields.

    PubMed

    Wandell, Brian A; Winawer, Jonathan

    2015-06-01

    Functional magnetic resonance imaging (fMRI) noninvasively measures human brain activity at millimeter resolution. Scientists use different approaches to take advantage of the remarkable opportunities presented by fMRI. Here, we describe progress using the computational neuroimaging approach in human visual cortex, which aims to build models that predict the neural responses from the stimulus and task. We focus on a particularly active area of research, the use of population receptive field (pRF) models to characterize human visual cortex responses to a range of stimuli, in a variety of tasks and different subject populations. PMID:25850730

  2. Atypical neuroimaging in Wilson’s disease

    PubMed Central

    Patell, Rushad; Dosi, Rupal; Joshi, Harshal K; Storz, Dennis

    2014-01-01

    Wilson's disease is a rare metabolic disease involving copper metabolism. Neuroimaging plays an important part in evaluation of patients with a neuropsychiatric presentation. We present a case of a 14-year-old girl with atypical confluent white matter disease and cystic degeneration on MRI, with a rapidly progressive course, who succumbed to complications despite treatment with trientine. Wilson's disease should be considered as a differential for leucoencephalopathy in young patients with progressive neurological disease for its early recognition and optimum outcome. PMID:24907221

  3. Vitamin D and Risk of Neuroimaging Abnormalities

    PubMed Central

    Littlejohns, Thomas J.; Kos, Katarina; Henley, William E.; Lang, Iain A.; Annweiler, Cedric; Beauchet, Olivier; Chaves, Paulo H. M.; Kestenbaum, Bryan R.; Kuller, Lewis H.; Langa, Kenneth M.; Lopez, Oscar L.; Llewellyn, David J.

    2016-01-01

    Vitamin D deficiency has been linked with an increased risk of incident all-cause dementia and Alzheimer’s disease. The aim of the current study was to explore the potential mechanisms underlying these associations by determining whether low vitamin D concentrations are associated with the development of incident cerebrovascular and neurodegenerative neuroimaging abnormalities. The population consisted of 1,658 participants aged ≥65 years from the US-based Cardiovascular Health Study who were free from prevalent cardiovascular disease, stroke and dementia at baseline in 1992–93. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were determined by liquid chromatography-tandem mass spectrometry from blood samples collected at baseline. The first MRI scan was conducted between 1991–1994 and the second MRI scan was conducted between 1997–1999. Change in white matter grade, ventricular grade and presence of infarcts between MRI scan one and two were used to define neuroimaging abnormalities. During a mean follow-up of 5.0 years, serum 25(OH)D status was not significantly associated with the development of any neuroimaging abnormalities. Using logistic regression models, the multivariate adjusted odds ratios (95% confidence interval) for worsening white matter grade in participants who were severely 25(OH)D deficient (<25 nmol/L) and deficient (≥25–50 nmol/L) were 0.76 (0.35–1.66) and 1.09 (0.76–1.55) compared to participants with sufficient concentrations (≥50 nmol/L). The multivariate adjusted odds ratios for ventricular grade in participants who were severely 25(OH)D deficient and deficient were 0.49 (0.20–1.19) and 1.12 (0.79–1.59) compared to those sufficient. The multivariate adjusted odds ratios for incident infarcts in participants who were severely 25(OH)D deficient and deficient were 1.95 (0.84–4.54) and 0.73 (0.47–1.95) compared to those sufficient. Overall, serum vitamin D concentrations could not be shown to be associated with

  4. Vitamin D and Risk of Neuroimaging Abnormalities.

    PubMed

    Littlejohns, Thomas J; Kos, Katarina; Henley, William E; Lang, Iain A; Annweiler, Cedric; Beauchet, Olivier; Chaves, Paulo H M; Kestenbaum, Bryan R; Kuller, Lewis H; Langa, Kenneth M; Lopez, Oscar L; Llewellyn, David J

    2016-01-01

    Vitamin D deficiency has been linked with an increased risk of incident all-cause dementia and Alzheimer's disease. The aim of the current study was to explore the potential mechanisms underlying these associations by determining whether low vitamin D concentrations are associated with the development of incident cerebrovascular and neurodegenerative neuroimaging abnormalities. The population consisted of 1,658 participants aged ≥65 years from the US-based Cardiovascular Health Study who were free from prevalent cardiovascular disease, stroke and dementia at baseline in 1992-93. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were determined by liquid chromatography-tandem mass spectrometry from blood samples collected at baseline. The first MRI scan was conducted between 1991-1994 and the second MRI scan was conducted between 1997-1999. Change in white matter grade, ventricular grade and presence of infarcts between MRI scan one and two were used to define neuroimaging abnormalities. During a mean follow-up of 5.0 years, serum 25(OH)D status was not significantly associated with the development of any neuroimaging abnormalities. Using logistic regression models, the multivariate adjusted odds ratios (95% confidence interval) for worsening white matter grade in participants who were severely 25(OH)D deficient (<25 nmol/L) and deficient (≥25-50 nmol/L) were 0.76 (0.35-1.66) and 1.09 (0.76-1.55) compared to participants with sufficient concentrations (≥50 nmol/L). The multivariate adjusted odds ratios for ventricular grade in participants who were severely 25(OH)D deficient and deficient were 0.49 (0.20-1.19) and 1.12 (0.79-1.59) compared to those sufficient. The multivariate adjusted odds ratios for incident infarcts in participants who were severely 25(OH)D deficient and deficient were 1.95 (0.84-4.54) and 0.73 (0.47-1.95) compared to those sufficient. Overall, serum vitamin D concentrations could not be shown to be associated with the development of

  5. Neuroimaging Features of San Luis Valley Syndrome

    PubMed Central

    Whitehead, Matthew T.; Lee, Bonmyong

    2015-01-01

    A 14-month-old Hispanic female with a history of double-outlet right ventricle and developmental delay in the setting of recombinant chromosome 8 syndrome was referred for neurologic imaging. Brain MR revealed multiple abnormalities primarily affecting midline structures, including commissural dysgenesis, vermian and brainstem hypoplasia/dysplasia, an interhypothalamic adhesion, and an epidermoid between the frontal lobes that enlarged over time. Spine MR demonstrated hypoplastic C1 and C2 posterior elements, scoliosis, and a borderline low conus medullaris position. Presented herein is the first illustration of neuroimaging findings from a patient with San Luis Valley syndrome. PMID:26425383

  6. Hybrid MR-PET in Neuroimaging.

    PubMed

    Bisdas, S; Lá Fougere, C; Ernemann, U

    2015-10-01

    Hybrid magnetic resonance (MR)-positron emission tomography (MR-PET) is a novel technology with advantages over sequential MR and PET imaging, allowing maintain full individual diagnostic performance with negligible mutual interference between the two hardware settings. Obvious synergies between MR and PET in acquisition of anatomical, functional, and molecular information for neurological diseases into one single image pave the way for establishing clear clinical indications for hybrid MR-PET as well as addressing unmet neuroimaging needs in future clinics and research. Further developments in attenuation correction, quantification, workflow, and effective MR-PET data management might unfold the full potential of integrated multimodality imaging. PMID:26227618

  7. Language context modulates reading route: an electrical neuroimaging study

    PubMed Central

    Buetler, Karin A.; de León Rodríguez, Diego; Laganaro, Marina; Müri, René; Spierer, Lucas; Annoni, Jean-Marie

    2014-01-01

    Introduction: The orthographic depth hypothesis (Katz and Feldman, 1983) posits that different reading routes are engaged depending on the type of grapheme/phoneme correspondence of the language being read. Shallow orthographies with consistent grapheme/phoneme correspondences favor encoding via non-lexical pathways, where each grapheme is sequentially mapped to its corresponding phoneme. In contrast, deep orthographies with inconsistent grapheme/phoneme correspondences favor lexical pathways, where phonemes are retrieved from specialized memory structures. This hypothesis, however, lacks compelling empirical support. The aim of the present study was to investigate the impact of orthographic depth on reading route selection using a within-subject design. Method: We presented the same pseudowords (PWs) to highly proficient bilinguals and manipulated the orthographic depth of PW reading by embedding them among two separated German or French language contexts, implicating respectively, shallow or deep orthography. High density electroencephalography was recorded during the task. Results: The topography of the ERPs to identical PWs differed 300–360 ms post-stimulus onset when the PWs were read in different orthographic depth context, indicating distinct brain networks engaged in reading during this time window. The brain sources underlying these topographic effects were located within left inferior frontal (German > French), parietal (French > German) and cingular areas (German > French). Conclusion: Reading in a shallow context favors non-lexical pathways, reflected in a stronger engagement of frontal phonological areas in the shallow versus the deep orthographic context. In contrast, reading PW in a deep orthographic context recruits less routine non-lexical pathways, reflected in a stronger engagement of visuo-attentional parietal areas in the deep versus shallow orthographic context. These collective results support a modulation of reading route by orthographic depth. PMID:24600377

  8. Evidence for Non-neutral Evolution in a Sodium Channel Gene in African Weakly Electric Fish (Campylomormyrus, Mormyridae).

    PubMed

    Paul, Christiane; Kirschbaum, Frank; Mamonekene, Victor; Tiedemann, Ralph

    2016-08-01

    Voltage-gated sodium channels, Nav1, play a crucial role in the generation and propagation of action potentials and substantially contribute to the shape of their rising phase. The electric organ discharge (EOD) of African weakly electric fish (Mormyroidea) is the sum of action potentials fired from all electrocytes of the electric organ at the same time and hence voltage-gated sodium channels are one factor-together with the electrocyte's morphology and innervation pattern-that determines the properties of these EODs. Due to the fish-specific genome duplication, teleost fish possess eight copies of sodium channel genes (SCN), which encode for Nav1 channels. In mormyroids, SCN4aa is solely expressed in the electrocytes of the adult electric organ. In this study, we compared entire SCN4aa sequences of six species of the genus Campylomormyrus and identified nonsynonymous substitutions among them. SCN4aa in Campylomormyrus exhibits a much higher evolutionary rate compared to its paralog SCN4ab, whose expression is not restricted to the electric organ. We also found evidence for strong positive selection on the SCN4aa gene within Mormyridae and along the lineage ancestral to the Mormyridae. We have identified sites at which all nonelectric teleosts are monomorphic in their amino acid, but mormyrids have different amino acids. Our findings confirm the crucial role of SCN4aa in EOD evolution among mormyrid weakly electric fish. The inferred positive selection within Mormyridae makes this gene a prime candidate for further investigation of the divergent evolution of pulse-type EODs among closely related species. PMID:27481396

  9. Off-Grid Electricity Access and its Impact on Micro-Enterprises: Evidence from Rural Uganda

    NASA Astrophysics Data System (ADS)

    Muhoro, Peter N.

    The history of development shows convincingly that no country has substantially reduced poverty without massively increasing the use of electricity. The development of micro-enterprises in rural areas of Uganda is linked with increased access and use of electricity services. In this study, I combine quantitative and qualitative methods, including informal surveys, intra-business energy allocation studies and historical analysis, to analyze off-grid electricity access among micro-enterprises in rural western Uganda. I explore the linkages between of grid electricity access and the influence it has on micro- enterprises. Data is obtained from 56 micro-enterprises located in 11 village-towns within 3 districts in Uganda. In studying the micro-enterprises. the focus is on the services that are provided by electricity from modern energy carriers. The type of equipment used, forms of transportation, technical support, level of understanding and education of the entrepreneur, financing for energy equipment, and the role of donors are discussed in this thesis. Qualitative methods are used to allow for new insights and prioritization of concepts to emerge from the field rattier than from theory. Micro-enterprises in rural Uganda create income for the poor; they are resources for poverty reduction. With price adjustments, it becomes possible for those who live below the poverty line, nominally less than $1 a day, to afford the products and services and therefore mitigating the vicious cycle of poverty. Energy consumption among the micro-enterprises is at an average of 0.13kWh/day. The cost of accessing this amount of electricity attributes to about 50% of total revenue. I find that the "practices" used in off-grid electricity access lead to situations where the entrepreneurs have to evaluate pricing and output of products and services to generate higher profits. Such numbers indicate the need for appropriate technologies and profitable policies to be implemented. The data

  10. Evidence-Based Systematic Review: Effects of Neuromuscular Electrical Stimulation on Swallowing and Neural Activation

    ERIC Educational Resources Information Center

    Clark, Heather; Lazarus, Cathy; Arvedson, Joan; Schooling, Tracy; Frymark, Tobi

    2009-01-01

    Purpose: To systematically review the literature examining the effects of neuromuscular electrical stimulation (NMES) on swallowing and neural activation. The review was conducted as part of a series examining the effects of oral motor exercises (OMEs) on speech, swallowing, and neural activation. Method: A systematic search was conducted to…

  11. Experimental evidence of tunable space-charge-layer-induced electrical properties of nanocrystalline ceria thin films.

    PubMed

    Lee, Kyung-Ryul; Lee, Jong-Ho; Yoo, Han-Ill

    2013-10-01

    Fully dense nanocrystalline ceria films were successfully deposited on a MgO single crystal by pulsed laser deposition (PLD). The electrical conductivity of the nanocrystalline thin film was 20 times higher than that of the bulk sample. The activation energy of bulk ceria was 2.3 eV, whereas the activation energy of the nanocrystalline sample was only 1.2 eV. After post-annealing at 1273 K in which the grain size of the nanocrystalline thin film increased to ~400 nm, the electrical conductivity and activation energy of the film were changed similar to those of bulk. These unique electrical properties of the nano-crystalline thin-film can be attributed to the grain size effect, or more specifically, to the space charge layer (SCL) effect. Furthermore, the electrical conductivity of the nanocrystalline thin film became similar to that of the bulk in an extremely reducing atmosphere because of the unusual dependence of the SCL effect on the oxygen partial pressure. PMID:23942424

  12. Evidence of a noon-to-midnight electric field in Saturn's inner magnetosphere, using microsignatures

    NASA Astrophysics Data System (ADS)

    Andriopoulou, M.; Roussos, E.; Krupp, N.; Paranicas, C.; Thomsen, M.; Krimigis, S.; Dougherty, M. K.; Glassmeier, K.-H.

    2012-04-01

    Using electron data of the MIMI-LEMMS detector that is onboard the Cassini spacecraft, we have created new, updated catalogues of energetic electron microsignature events caused by the Kronian moons Tethys and Dione. We studied the deviations of the moon's wake from the nearly circular path of the orbit of the moon-absorber and observed significant radial displacements that exhibit systematic asymmetries with respect to the local time, following a systematic trend: inward in the nightside and outward in the dayside of the inner magnetosphere. We show that these asymmetries cannot be explained by asymmetries of the magnetic field in the inner magnetosphere. We developed several methods to associate the properties of the displacements to magnetospheric electric fields. Our results are consistent with an electric field that has a noon-to-midnight orientation and amplitudes that do not exceed 1 mV/m. Such an electric field is not predicted by any theoretical model and its origin is still unknown. While several ongoing studies are in agreement with our result, the radial displacement of microsignatures is the most sensitive tracer of this electric field so we will also discuss how the microsignature dataset can be used to put tighter constraints on its properties and origin.

  13. Reproducibility of neuroimaging analyses across operating systems

    PubMed Central

    Glatard, Tristan; Lewis, Lindsay B.; Ferreira da Silva, Rafael; Adalat, Reza; Beck, Natacha; Lepage, Claude; Rioux, Pierre; Rousseau, Marc-Etienne; Sherif, Tarek; Deelman, Ewa; Khalili-Mahani, Najmeh; Evans, Alan C.

    2015-01-01

    Neuroimaging pipelines are known to generate different results depending on the computing platform where they are compiled and executed. We quantify these differences for brain tissue classification, fMRI analysis, and cortical thickness (CT) extraction, using three of the main neuroimaging packages (FSL, Freesurfer and CIVET) and different versions of GNU/Linux. We also identify some causes of these differences using library and system call interception. We find that these packages use mathematical functions based on single-precision floating-point arithmetic whose implementations in operating systems continue to evolve. While these differences have little or no impact on simple analysis pipelines such as brain extraction and cortical tissue classification, their accumulation creates important differences in longer pipelines such as subcortical tissue classification, fMRI analysis, and cortical thickness extraction. With FSL, most Dice coefficients between subcortical classifications obtained on different operating systems remain above 0.9, but values as low as 0.59 are observed. Independent component analyses (ICA) of fMRI data differ between operating systems in one third of the tested subjects, due to differences in motion correction. With Freesurfer and CIVET, in some brain regions we find an effect of build or operating system on cortical thickness. A first step to correct these reproducibility issues would be to use more precise representations of floating-point numbers in the critical sections of the pipelines. The numerical stability of pipelines should also be reviewed. PMID:25964757

  14. Retrospective study on structural neuroimaging in first-episode psychosis

    PubMed Central

    Silva-dos-Santos, Amilcar; Talina, Miguel Cotrim

    2016-01-01

    Background. No consensus between guidelines exists regarding neuroimaging in first-episode psychosis. The purpose of this study is to assess anomalies found in structural neuroimaging exams (brain computed tomography (CT) and magnetic resonance imaging (MRI)) in the initial medical work-up of patients presenting first-episode psychosis. Methods. The study subjects were 32 patients aged 18–48 years (mean age: 29.6 years), consecutively admitted with first-episode psychosis diagnosis. Socio-demographic and clinical data and neuroimaging exams (CT and MRI) were retrospectively studied. Diagnostic assessments were made using the Operational Criteria Checklist +. Neuroimaging images (CT and MRI) and respective reports were analysed by an experienced consultant psychiatrist. Results. None of the patients had abnormalities in neuroimaging exams responsible for psychotic symptoms. Thirty-seven percent of patients had incidental brain findings not causally related to the psychosis (brain atrophy, arachnoid cyst, asymmetric lateral ventricles, dilated lateral ventricles, plagiocephaly and falx cerebri calcification). No further medical referral was needed for any of these patients. No significant differences regarding gender, age, diagnosis, duration of untreated psychosis, in-stay and cannabis use were found between patients who had neuroimaging abnormalities versus those without. Discussion. This study suggests that structural neuroimaging exams reveal scarce abnormalities in young patients with first-episode psychosis. Structural neuroimaging is especially useful in first-episode psychosis patients with neurological symptoms, atypical clinical picture and old age. PMID:27257547

  15. Retrospective study on structural neuroimaging in first-episode psychosis.

    PubMed

    Coentre, Ricardo; Silva-Dos-Santos, Amilcar; Talina, Miguel Cotrim

    2016-01-01

    Background. No consensus between guidelines exists regarding neuroimaging in first-episode psychosis. The purpose of this study is to assess anomalies found in structural neuroimaging exams (brain computed tomography (CT) and magnetic resonance imaging (MRI)) in the initial medical work-up of patients presenting first-episode psychosis. Methods. The study subjects were 32 patients aged 18-48 years (mean age: 29.6 years), consecutively admitted with first-episode psychosis diagnosis. Socio-demographic and clinical data and neuroimaging exams (CT and MRI) were retrospectively studied. Diagnostic assessments were made using the Operational Criteria Checklist +. Neuroimaging images (CT and MRI) and respective reports were analysed by an experienced consultant psychiatrist. Results. None of the patients had abnormalities in neuroimaging exams responsible for psychotic symptoms. Thirty-seven percent of patients had incidental brain findings not causally related to the psychosis (brain atrophy, arachnoid cyst, asymmetric lateral ventricles, dilated lateral ventricles, plagiocephaly and falx cerebri calcification). No further medical referral was needed for any of these patients. No significant differences regarding gender, age, diagnosis, duration of untreated psychosis, in-stay and cannabis use were found between patients who had neuroimaging abnormalities versus those without. Discussion. This study suggests that structural neuroimaging exams reveal scarce abnormalities in young patients with first-episode psychosis. Structural neuroimaging is especially useful in first-episode psychosis patients with neurological symptoms, atypical clinical picture and old age. PMID:27257547

  16. Functional neuroimaging can support causal claims about brain function

    PubMed Central

    Weber, Matthew J.; Thompson-Schill, Sharon L.

    2013-01-01

    Cognitive neuroscientists habitually deny that functional neuroimaging can furnish causal information about the relationship between brain events and behavior. However, imaging studies do provide causal information about those relationships—though not causal certainty. Although popular portrayals of functional neuroimaging tend to attribute too much inferential power to the technique, we should restrain ourselves from ascribing it too little. PMID:20201629

  17. Neuroimaging in Communication Sciences and Disorders: An Introduction.

    ERIC Educational Resources Information Center

    Plante, Elena

    2001-01-01

    This introductory article introduces papers that present examples of neuroimaging applications in the field of communication sciences and disorders. It notes that neuroimaging studies were usually an outgrowth of earlier behavioral research or clinical observations with knowledge of the disorder's behavioral characteristic critical to development…

  18. Cognitive Neuroimaging: Cognitive Science out of the Armchair

    ERIC Educational Resources Information Center

    de Zubicaray, Greig I.

    2006-01-01

    Cognitive scientists were not quick to embrace the functional neuroimaging technologies that emerged during the late 20th century. In this new century, cognitive scientists continue to question, not unreasonably, the relevance of functional neuroimaging investigations that fail to address questions of interest to cognitive science. However, some…

  19. Communicating with vegetative state patients: the role of neuroimaging in American disability law.

    PubMed

    Taylor, Dalia B

    2014-06-01

    Patients in vegetative states appear to be awake but unconscious. If they have been in a vegetative state for more than one year, they have little chance of ever recovering. Additionally, no one can communicate with them, including physicians, loved ones, and families. However, new scientific evidence has challenged our understanding of this bleak reality. In particular, recent neuroscience research has shown that a substantial number of patients in vegetative states may actually be conscious and able to communicate through the use of brain-scanning technology. This exciting development poses many difficult questions, including the one analyzed here: now that we know neuroimaging may be the only way to communicate with these patients, will health care facilities be required to provide brain-scanning equipment under American disability law? This Note argues that lawsuits seeking neuroimaging technology from hospitals have a significant chance of success. The main challenge for plaintiffs will be convincing judges that existing scientific evidence actually shows that neuroimaging can facilitate communication with patients. Ultimately, if the appropriate legal framework develops, brain-scanning technology could permit patients in vegetative states to make decisions regarding their own medical care and allow families to communicate with their loved ones. PMID:25004549

  20. Biochemical and neuroimaging studies in subjective cognitive decline: progress and perspectives.

    PubMed

    Sun, Yu; Yang, Fu-Chi; Lin, Ching-Po; Han, Ying

    2015-10-01

    Neurodegeneration due to Alzheimer's disease (AD) can progress over decades before dementia becomes apparent. Indeed, patients with mild cognitive impairment (MCI) already demonstrate significant lesion loads. In most cases, MCI is preceded by subjective cognitive decline (SCD), which is applied to individuals who have self-reported memory-related complaints and has been associated with a higher risk of future cognitive decline and conversion to dementia. Based on the schema of a well-received model of biomarker dynamics in AD pathogenesis, it has been postulated that SCD symptoms may result from compensatory changes in response to β-amyloid accumulation and neurodegeneration. Although SCD is considered a prodromal stage of MCI, it is also a common manifestation in old age, independent of AD, and the predictive value of SCD for AD pathology remains controversial. Here, we provide a review focused on the contributions of cross-sectional and longitudinal analogical studies of biomarkers and neuroimaging evidence in disentangling under what conditions SCD may be attributable to AD pathology. In conclusion, there is promising evidence indicating that clinicians should be able to differentiate pre-AD SCD based on the presence of pathophysiological biomarkers in cerebrospinal fluid (CSF) and neuroimaging. However, this neuroimaging approach is still at an immature stage without an established rubric of standards. A substantial amount of work remains in terms of replicating recent findings and validating the clinical utility of identifying SCD. PMID:25864576

  1. A Review on the Bioinformatics Tools for Neuroimaging.

    PubMed

    Man, Mei Yen; Ong, Mei Sin; Mohamad, Mohd Saberi; Deris, Safaai; Sulong, Ghazali; Yunus, Jasmy; Che Harun, Fauzan Khairi

    2015-12-01

    Neuroimaging is a new technique used to create images of the structure and function of the nervous system in the human brain. Currently, it is crucial in scientific fields. Neuroimaging data are becoming of more interest among the circle of neuroimaging experts. Therefore, it is necessary to develop a large amount of neuroimaging tools. This paper gives an overview of the tools that have been used to image the structure and function of the nervous system. This information can help developers, experts, and users gain insight and a better understanding of the neuroimaging tools available, enabling better decision making in choosing tools of particular research interest. Sources, links, and descriptions of the application of each tool are provided in this paper as well. Lastly, this paper presents the language implemented, system requirements, strengths, and weaknesses of the tools that have been widely used to image the structure and function of the nervous system. PMID:27006633

  2. Colorful brains: 14 years of display practice in functional neuroimaging.

    PubMed

    Christen, Markus; Vitacco, Deborah A; Huber, Lara; Harboe, Julie; Fabrikant, Sara I; Brugger, Peter

    2013-06-01

    Neuroimaging results are typically graphically rendered and color-coded, which influences the process of knowledge generation within neuroscience as well as the public perception of brain research. Analyzing these issues requires empirical information on the display practice in neuroimaging. In our study we evaluated more than 9000 functional images (fMRI and PET) published between 1996 and 2009 with respect to the use of color, image structure, image production software and other factors that may determine the display practice. We demonstrate a variety of display styles despite a remarkable dominance of few image production sites and software systems, outline some tendencies of standardization, and identify shortcomings with respect to color scale explication in neuroimages. We discuss the importance of the finding for knowledge production in neuroimaging, and we make suggestions to improve the display practice in neuroimaging, especially on regimes of color coding. PMID:23403183

  3. A Review on the Bioinformatics Tools for Neuroimaging

    PubMed Central

    MAN, Mei Yen; ONG, Mei Sin; Mohamad, Mohd Saberi; DERIS, Safaai; SULONG, Ghazali; YUNUS, Jasmy; CHE HARUN, Fauzan Khairi

    2015-01-01

    Neuroimaging is a new technique used to create images of the structure and function of the nervous system in the human brain. Currently, it is crucial in scientific fields. Neuroimaging data are becoming of more interest among the circle of neuroimaging experts. Therefore, it is necessary to develop a large amount of neuroimaging tools. This paper gives an overview of the tools that have been used to image the structure and function of the nervous system. This information can help developers, experts, and users gain insight and a better understanding of the neuroimaging tools available, enabling better decision making in choosing tools of particular research interest. Sources, links, and descriptions of the application of each tool are provided in this paper as well. Lastly, this paper presents the language implemented, system requirements, strengths, and weaknesses of the tools that have been widely used to image the structure and function of the nervous system. PMID:27006633

  4. Advances in neuroimaging research of schizophrenia in China

    PubMed Central

    LIU, Dengtang; XU, Yifeng; JIANG, Kaida

    2014-01-01

    Summary Since Hounsfield’s first report about X-ray computed tomography (CT) in 1972, there has been substantial progress in the application of neuroimaging techniques to study the structure, function, and biochemistry of the brain. This review provides a summary of recent research in structural and functional neuroimaging of schizophrenia in China and four tables describing all of the relevant studies from mainland China. The first research report using neuroimaging techniques in China dates back to 1983, a study that reported encephalatrophy in 30% of individuals with schizophrenia. Functional neuroimaging research in China emerged in the 1990s and has undergone rapid development since. Recently, structural and functional brain networks has become a hot topic among China’s neuroimaging researchers. PMID:25317005

  5. Neuroimaging of Natalizumab Complications in Multiple Sclerosis: PML and Other Associated Entities

    PubMed Central

    Honce, Justin M.; Nagae, Lidia; Nyberg, Eric

    2015-01-01

    Natalizumab (Tysabri) is a monoclonal antibody (α4 integrin antagonist) approved for treatment of multiple sclerosis, both for patients who fail therapy with other disease modifying agents and for patients with aggressive disease. Natalizumab is highly effective, resulting in significant decreases in rates of both relapse and disability accumulation, as well as marked decrease in MRI evidence of disease activity. As such, utilization of natalizumab is increasing, and the presentation of its associated complications is increasing accordingly. This review focuses on the clinical and neuroimaging features of the major complications associated with natalizumab therapy, focusing on the rare but devastating progressive multifocal leukoencephalopathy (PML). Associated entities including PML associated immune reconstitution inflammatory syndrome (PML-IRIS) and the emerging phenomenon of rebound of MS disease activity after natalizumab discontinuation are also discussed. Early recognition of neuroimaging features associated with these processes is critical in order to facilitate prompt diagnosis, treatment, and/or modification of therapies to improve patient outcomes. PMID:26483978

  6. Genetic and Neuroimaging Features of Personality Disorders: State of the Art.

    PubMed

    Ma, Guorong; Fan, Hongying; Shen, Chanchan; Wang, Wei

    2016-06-01

    Personality disorders often act as a common denominator for many psychiatric problems, and studies on personality disorders contribute to the etiopathology, diagnosis, and treatment of many mental disorders. In recent years, increasing evidence from various studies has shown distinctive features of personality disorders, and that from genetic and neuroimaging studies has been especially valuable. Genetic studies primarily target the genes encoding neurotransmitters and enzymes in the serotoninergic and dopaminergic systems, and neuroimaging studies mainly focus on the frontal and temporal lobes as well as the limbic-paralimbic system in patients with personality disorders. Although some studies have suffered due to unclear diagnoses of personality disorders and some have included few patients for a given personality disorder, great opportunities remain for investigators to launch new ideas and technologies in the field. PMID:27037690

  7. Aging, Neurodegenerative Disease, and Traumatic Brain Injury: The Role of Neuroimaging

    PubMed Central

    Levine, Brian

    2015-01-01

    Abstract Traumatic brain injury (TBI) is a highly prevalent condition with significant effects on cognition and behavior. While the acute and sub-acute effects of TBI recover over time, relatively little is known about the long-term effects of TBI in relation to neurodegenerative disease. This issue has recently garnered a great deal of attention due to publicity surrounding chronic traumatic encephalopathy (CTE) in professional athletes, although CTE is but one of several neurodegenerative disorders associated with a history of TBI. Here, we review the literative on neurodegenerative disorders linked to remote TBI. We also review the evidence for neuroimaging changes associated with unhealthy brain aging in the context of remote TBI. We conclude that neuroimaging biomarkers have significant potential to increase understanding of the mechanisms of unhealthy brain aging and neurodegeneration following TBI, with potential for identifying those at risk for unhealthy brain aging prior to the clinical manifestation of neurodegenerative disease. PMID:25192426

  8. Neuroimaging of Natalizumab Complications in Multiple Sclerosis: PML and Other Associated Entities.

    PubMed

    Honce, Justin M; Nagae, Lidia; Nyberg, Eric

    2015-01-01

    Natalizumab (Tysabri) is a monoclonal antibody (α4 integrin antagonist) approved for treatment of multiple sclerosis, both for patients who fail therapy with other disease modifying agents and for patients with aggressive disease. Natalizumab is highly effective, resulting in significant decreases in rates of both relapse and disability accumulation, as well as marked decrease in MRI evidence of disease activity. As such, utilization of natalizumab is increasing, and the presentation of its associated complications is increasing accordingly. This review focuses on the clinical and neuroimaging features of the major complications associated with natalizumab therapy, focusing on the rare but devastating progressive multifocal leukoencephalopathy (PML). Associated entities including PML associated immune reconstitution inflammatory syndrome (PML-IRIS) and the emerging phenomenon of rebound of MS disease activity after natalizumab discontinuation are also discussed. Early recognition of neuroimaging features associated with these processes is critical in order to facilitate prompt diagnosis, treatment, and/or modification of therapies to improve patient outcomes. PMID:26483978

  9. Age of Onset of Schizophrenia: Perspectives From Structural Neuroimaging Studies

    PubMed Central

    Gogtay, Nitin; Vyas, Nora S.; Testa, Renee; Wood, Stephen J.; Pantelis, Christos

    2011-01-01

    Many of the major neuropsychiatric illnesses, including schizophrenia, have a typical age of onset in late adolescence. Late adolescence may reflect a critical period in brain development making it particularly vulnerable for the onset of psychopathology. Neuroimaging studies that focus on this age range may provide unique insights into the onset and course of psychosis. In this review, we examine the evidence from 2 unique longitudinal cohorts that span the ages from early childhood through young adulthood; a study of childhood-onset schizophrenia where patients and siblings are followed from ages 6 through to their early twenties, and an ultra-high risk study where subjects (mean age of 19 years) are studied before and after the onset of psychosis. From the available evidence, we make an argument that subtle, regionally specific, and genetically influenced alterations during developmental age windows influence the course of psychosis and the resultant brain phenotype. The importance of examining trajectories of development and the need for future combined approaches, using multimodal imaging together with molecular studies is discussed. PMID:21505117

  10. Age of onset of schizophrenia: perspectives from structural neuroimaging studies.

    PubMed

    Gogtay, Nitin; Vyas, Nora S; Testa, Renee; Wood, Stephen J; Pantelis, Christos

    2011-05-01

    Many of the major neuropsychiatric illnesses, including schizophrenia, have a typical age of onset in late adolescence. Late adolescence may reflect a critical period in brain development making it particularly vulnerable for the onset of psychopathology. Neuroimaging studies that focus on this age range may provide unique insights into the onset and course of psychosis. In this review, we examine the evidence from 2 unique longitudinal cohorts that span the ages from early childhood through young adulthood; a study of childhood-onset schizophrenia where patients and siblings are followed from ages 6 through to their early twenties, and an ultra-high risk study where subjects (mean age of 19 years) are studied before and after the onset of psychosis. From the available evidence, we make an argument that subtle, regionally specific, and genetically influenced alterations during developmental age windows influence the course of psychosis and the resultant brain phenotype. The importance of examining trajectories of development and the need for future combined approaches, using multimodal imaging together with molecular studies is discussed. PMID:21505117

  11. The glutamate hypothesis of schizophrenia: neuroimaging and drug development.

    PubMed

    Egerton, Alice; Stone, James M

    2012-06-01

    Over the last 50 years, evidence for central involvement of glutamatergic neurotransmission in the pathophysiology of schizophrenia has accumulated. Recent advances in neuroimaging technology now allow several components of glutamatergic neurotransmission to be assessed in the living human brain. Positron emission tomography (PET) or single photon emission tomography (SPET) in combination with select radiotracers allows visualization of glutamatergic receptors in vivo, and magnetic resonance (MR) - based techniques allow mapping of the effects of glutamatergic agents on regional brain activation, and the measurement of regional glutamate concentrations. These imaging studies have provided evidence for regional glutamatergic abnormalities in psychosis, and are beginning to describe both the evolution of these abnormalities over the course of the illness and their response to therapeutic intervention. In parallel, advances in small animal imaging and the development of animal models have provided a platform to explore the neuropathological consequences of glutamatergic abnormality, and the potential antipsychotic efficacy of novel compounds. The molecular diversity of the glutamatergic system has driven the design of several compounds targeting aspects of glutamatergic transmission, and clinical trials have yielded encouraging results. Here, we review the contribution of imaging studies to date in understanding glutamatergic abnormalities in psychosis, and discuss the potential of new glutamatergic compounds for treatment of the disorder. PMID:22283750

  12. Systems Biology, Neuroimaging, Neuropsychology, Neuroconnectivity and Traumatic Brain Injury

    PubMed Central

    Bigler, Erin D.

    2016-01-01

    The patient who sustains a traumatic brain injury (TBI) typically undergoes neuroimaging studies, usually in the form of computed tomography (CT) and magnetic resonance imaging (MRI). In most cases the neuroimaging findings are clinically assessed with descriptive statements that provide qualitative information about the presence/absence of visually identifiable abnormalities; though little if any of the potential information in a scan is analyzed in any quantitative manner, except in research settings. Fortunately, major advances have been made, especially during the last decade, in regards to image quantification techniques, especially those that involve automated image analysis methods. This review argues that a systems biology approach to understanding quantitative neuroimaging findings in TBI provides an appropriate framework for better utilizing the information derived from quantitative neuroimaging and its relation with neuropsychological outcome. Different image analysis methods are reviewed in an attempt to integrate quantitative neuroimaging methods with neuropsychological outcome measures and to illustrate how different neuroimaging techniques tap different aspects of TBI-related neuropathology. Likewise, how different neuropathologies may relate to neuropsychological outcome is explored by examining how damage influences brain connectivity and neural networks. Emphasis is placed on the dynamic changes that occur following TBI and how best to capture those pathologies via different neuroimaging methods. However, traditional clinical neuropsychological techniques are not well suited for interpretation based on contemporary and advanced neuroimaging methods and network analyses. Significant improvements need to be made in the cognitive and behavioral assessment of the brain injured individual to better interface with advances in neuroimaging-based network analyses. By viewing both neuroimaging and neuropsychological processes within a systems biology

  13. Systems Biology, Neuroimaging, Neuropsychology, Neuroconnectivity and Traumatic Brain Injury.

    PubMed

    Bigler, Erin D

    2016-01-01

    The patient who sustains a traumatic brain injury (TBI) typically undergoes neuroimaging studies, usually in the form of computed tomography (CT) and magnetic resonance imaging (MRI). In most cases the neuroimaging findings are clinically assessed with descriptive statements that provide qualitative information about the presence/absence of visually identifiable abnormalities; though little if any of the potential information in a scan is analyzed in any quantitative manner, except in research settings. Fortunately, major advances have been made, especially during the last decade, in regards to image quantification techniques, especially those that involve automated image analysis methods. This review argues that a systems biology approach to understanding quantitative neuroimaging findings in TBI provides an appropriate framework for better utilizing the information derived from quantitative neuroimaging and its relation with neuropsychological outcome. Different image analysis methods are reviewed in an attempt to integrate quantitative neuroimaging methods with neuropsychological outcome measures and to illustrate how different neuroimaging techniques tap different aspects of TBI-related neuropathology. Likewise, how different neuropathologies may relate to neuropsychological outcome is explored by examining how damage influences brain connectivity and neural networks. Emphasis is placed on the dynamic changes that occur following TBI and how best to capture those pathologies via different neuroimaging methods. However, traditional clinical neuropsychological techniques are not well suited for interpretation based on contemporary and advanced neuroimaging methods and network analyses. Significant improvements need to be made in the cognitive and behavioral assessment of the brain injured individual to better interface with advances in neuroimaging-based network analyses. By viewing both neuroimaging and neuropsychological processes within a systems biology

  14. Neuroimaging for drug addiction and related behaviors

    PubMed Central

    Parvaz, Muhammad A.; Alia-Klein, Nelly; Woicik, Patricia A.; Volkow, Nora D.; Goldstein, Rita Z.

    2012-01-01

    In this review, we highlight the role of neuroimaging techniques in studying the emotional and cognitive-behavioral components of the addiction syndrome by focusing on the neural substrates subserving them. The phenomenology of drug addiction can be characterized by a recurrent pattern of subjective experiences that includes drug intoxication, craving, bingeing, and withdrawal with the cycle culminating in a persistent preoccupation with obtaining, consuming, and recovering from the drug. In the past two decades, imaging studies of drug addiction have demonstrated deficits in brain circuits related to reward and impulsivity. The current review focuses on studies employing positron emission tomography (PET), functional magnetic resonance imaging (fMRI), and electroencephalography (EEG) to investigate these behaviors in drug-addicted human populations. We begin with a brief account of drug addiction followed by a technical account of each of these imaging modalities. We then discuss how these techniques have uniquely contributed to a deeper understanding of addictive behaviors. PMID:22117165

  15. The Human Connectome Project's neuroimaging approach.

    PubMed

    Glasser, Matthew F; Smith, Stephen M; Marcus, Daniel S; Andersson, Jesper L R; Auerbach, Edward J; Behrens, Timothy E J; Coalson, Timothy S; Harms, Michael P; Jenkinson, Mark; Moeller, Steen; Robinson, Emma C; Sotiropoulos, Stamatios N; Xu, Junqian; Yacoub, Essa; Ugurbil, Kamil; Van Essen, David C

    2016-08-26

    Noninvasive human neuroimaging has yielded many discoveries about the brain. Numerous methodological advances have also occurred, though inertia has slowed their adoption. This paper presents an integrated approach to data acquisition, analysis and sharing that builds upon recent advances, particularly from the Human Connectome Project (HCP). The 'HCP-style' paradigm has seven core tenets: (i) collect multimodal imaging data from many subjects; (ii) acquire data at high spatial and temporal resolution; (iii) preprocess data to minimize distortions, blurring and temporal artifacts; (iv) represent data using the natural geometry of cortical and subcortical structures; (v) accurately align corresponding brain areas across subjects and studies; (vi) analyze data using neurobiologically accurate brain parcellations; and (vii) share published data via user-friendly databases. We illustrate the HCP-style paradigm using existing HCP data sets and provide guidance for future research. Widespread adoption of this paradigm should accelerate progress in understanding the brain in health and disease. PMID:27571196

  16. The experience of art: insights from neuroimaging.

    PubMed

    Nadal, Marcos

    2013-01-01

    The experience of art is a complex one. It emerges from the interaction of multiple cognitive and affective processes. Neuropsychological and neuroimaging studies are revealing the broadly distributed network of brain regions upon which it relies. This network can be divided into three functional components: (i) prefrontal, parietal, and temporal cortical regions support evaluative judgment, attentional processing, and memory retrieval; (ii) the reward circuit, including cortical, subcortical regions, and some of its regulators, is involved in the generation of pleasurable feelings and emotions, and the valuation and anticipation of reward; and (iii) attentional modulation of activity in low-, mid-, and high-level cortical sensory regions enhances the perceptual processing of certain features, relations, locations, or objects. Understanding how these regions act in concert to produce unique and moving art experiences and determining the impact of personal and cultural meaning and context on this network the biological foundation of the experience of art--remain future challenges. PMID:24041322

  17. Neuroimaging for drug addiction and related behaviors

    SciTech Connect

    Parvaz M. A.; Parvaz, M.A.; Alia-Klein, N.; Woicik,P.A.; Volkow, N.D.; Goldstein, R.Z.

    2011-10-01

    In this review, we highlight the role of neuroimaging techniques in studying the emotional and cognitive-behavioral components of the addiction syndrome by focusing on the neural substrates subserving them. The phenomenology of drug addiction can be characterized by a recurrent pattern of subjective experiences that includes drug intoxication, craving, bingeing, and withdrawal with the cycle culminating in a persistent preoccupation with obtaining, consuming, and recovering from the drug. In the past two decades, imaging studies of drug addiction have demonstrated deficits in brain circuits related to reward and impulsivity. The current review focuses on studies employing positron emission tomography (PET), functional magnetic resonance imaging (fMRI), and electroencephalography (EEG) to investigate these behaviors in drug-addicted human populations. We begin with a brief account of drug addiction followed by a technical account of each of these imaging modalities. We then discuss how these techniques have uniquely contributed to a deeper understanding of addictive behaviors.

  18. A simple tool for neuroimaging data sharing

    PubMed Central

    Haselgrove, Christian; Poline, Jean-Baptiste; Kennedy, David N.

    2014-01-01

    Data sharing is becoming increasingly common, but despite encouragement and facilitation by funding agencies, journals, and some research efforts, most neuroimaging data acquired today is still not shared due to political, financial, social, and technical barriers to sharing data that remain. In particular, technical solutions are few for researchers that are not a part of larger efforts with dedicated sharing infrastructures, and social barriers such as the time commitment required to share can keep data from becoming publicly available. We present a system for sharing neuroimaging data, designed to be simple to use and to provide benefit to the data provider. The system consists of a server at the International Neuroinformatics Coordinating Facility (INCF) and user tools for uploading data to the server. The primary design principle for the user tools is ease of use: the user identifies a directory containing Digital Imaging and Communications in Medicine (DICOM) data, provides their INCF Portal authentication, and provides identifiers for the subject and imaging session. The user tool anonymizes the data and sends it to the server. The server then runs quality control routines on the data, and the data and the quality control reports are made public. The user retains control of the data and may change the sharing policy as they need. The result is that in a few minutes of the user’s time, DICOM data can be anonymized and made publicly available, and an initial quality control assessment can be performed on the data. The system is currently functional, and user tools and access to the public image database are available at http://xnat.incf.org/. PMID:24904398

  19. Evidence of underground electric current generation during the 2009 L'Aquila earthquake: Real or instrumental?

    NASA Astrophysics Data System (ADS)

    Masci, F.; Thomas, J. N.

    2016-06-01

    We investigate magnetic effects in correspondence of the Mw6.1 L'Aquila earthquake. Magnetic and seismic records are analyzed. Rapid and distinct changes and an offset can be seen in magnetic field components after the main shock. We show that these effects result from electromagnetic induction due to the movement of the sensors through the Earth's magnetic field and from a permanent displacement of the sensors from their original position caused by the passing seismic waves. A transient signal in total field data from an overhauser magnetometer apparently occurs in correspondence with the earthquake. Our analysis shows that the transient was not observed by other sensors that were operating in close proximity to the overhauser. Thus, the transient signal in the total magnetic field data, and the offset in the magnetic field components, cannot be associated with a hypothetical underground electric current generated by the earthquake, as suggested by Nenovski (2015).

  20. How much do electric customers want to pay for reliability; New evidence on an old controversy

    SciTech Connect

    Woo, C.K. ); Pupp, R.L. ); Flaim, T.; Mango, R. )

    1991-01-01

    Electric utilities are facing competitive challenges from independent power producers, cogenerators, qualifying facilities, and customer bypass, in addition to increasing resistance to building new capacity whether it be conventional or nuclear. Utilities are meeting these challenges by offering an array of demand-side management programs and differentiated tariffs that better match utility rates and customer preferences for service reliability. Customer preferences for service reliability may be gathered by market survey, however, survey estimates are subject to various common criticisms a fact that has retarded the adoption of this approach. by using power survey design techniques and statistical methods, the authors show in this paper, how accurate customer value of service reliability data may be collected with a market survey.

  1. Evidence for room temperature electric polarization in RMn(2)O(5) multiferroics.

    PubMed

    Balédent, V; Chattopadhyay, S; Fertey, P; Lepetit, M B; Greenblatt, M; Wanklyn, B; Saouma, F O; Jang, J I; Foury-Leylekian, P

    2015-03-20

    It is established that the multiferroics RMn(2)O(5) crystallize in the centrosymmetric Pbam space group and that the magnetically induced electric polarization appearing at low temperature is accompanied by a symmetry breaking. However, both our present x-ray study-performed on compounds with R=Pr,Nd,Gd,Tb, and Dy-and first-principles calculations unambiguously rule out this picture. Based on structural refinements, geometry optimization, and physical arguments, we demonstrate in this Letter that the actual space group is likely to be Pm. This turns out to be of crucial importance for RMn(2)O(5) multiferroics since Pm is not centrosymmetric. Ferroelectricity is thus already present at room temperature, and its enhancement at low temperature is a spin-enhanced process. This result is also supported by direct observation of optical second harmonic generation. This fundamental result calls into question the actual theoretical approaches that describe the magnetoelectric coupling in this multiferroic family. PMID:25839307

  2. Whole cell electrochemistry of electricity-producing microorganisms evidence an adaptation for optimal exocellular electron transport.

    PubMed

    Busalmen, Juan Pablo; Esteve-Nuñez, Abraham; Feliu, Juan Miguel

    2008-04-01

    The mechanism(s) by which electricity-producing microorganisms interact with an electrode is poorly understood. Outer membrane cytochromes and conductive pili are being considered as possible players, but the available information does not concur to a consensus mechanism yet. In this work we demonstrate that Geobacter sulfurreducens cells are able to change the way in which they exchange electrons with an electrode as a response to changes in the applied electrode potential. After several hours of polarization at 0.1 V Ag/AgCl-KCl (saturated), the voltammetric signature of the attached cells showed a single redox pair with a formal redox potential of about -0.08 V as calculated from chronopotentiometric analysis. A similar signal was obtained from cells adapted to 0.4 V. However, new redox couples were detected after conditioning at 0.6 V. A large oxidation process beyond 0.5 V transferring a higher current than that obtained at 0.1 V was found to be associated with two reduction waves at 0.23 and 0.50 V. The apparent equilibrium potential of these new processes was estimated to be at about 0.48 V from programmed current potentiometric results. Importantly, when polarization was lowered again to 0.1 V for 18 additional hours, the signals obtained at 0.6 V were found to greatly diminish in amplitude, whereas those previously found at the lower conditioning potential were recovered. Results clearly show the reversibility of cell adaptation to the electrode potential and pointto the polarization potential as a key variable to optimize energy production from an electricity producing population. PMID:18504979

  3. Functional neuroimaging studies of post-traumatic stress disorder

    PubMed Central

    Hughes, Katherine C; Shin, Lisa M

    2011-01-01

    Post-traumatic stress disorder (PTSD) is a significant problem that can affect individuals who have been exposed to a traumatic event or events, such as combat, violent crime or childhood abuse. Over the past several years, neuroimaging studies of PTSD have focused on elucidating the brain circuits that mediate this disorder. In this article, we will briefly introduce some of the methods used in functional neuroimaging studies of PTSD. We will then review functional neuroimaging studies that have reported significant findings in the amygdala, medial prefrontal cortex, hippocampus and insula. Finally, we will suggest future directions for research. PMID:21306214

  4. The Current Impact of Incidental Findings Found during Neuroimaging on Neurologists’ Workloads

    PubMed Central

    Booth, Thomas C.; Boyd-Ellison, Jennifer M.

    2015-01-01

    Objective Neuroimaging is an important diagnostic tool in the assessment of neurological disease, but often unmasks Incidental Findings (IFs). The negative impacts of IFs, such as ‘patient’ anxiety, present neurologists with management dilemmas, largely due to the limited knowledge base surrounding the medical significance of these IFs. In particular, the lack of evidence-based clinical trials investigating the efficacy of treatments for subclinical IFs makes management protocols challenging. The objective was to determine the impact IFs may have on neurologists’ workloads and healthcare budgets and to examine neurologists’ concerns regarding the clinical management of these ‘patients’. Methods Qualitative research based on constructivist grounded theory. Data was collected through semi-structured interviews of purposively sampled neurologists, coded, and concurrent comparative analysis performed. A substantive theory of the ‘IF impacts’ was developed after concept saturation. Results Neurologists managed the escalating workload caused by an increased number of referrals of ‘patients’ with IFs found during neuroimaging; however it was unclear whether this was sustainable in the future. Neurologists experienced IF management dilemmas and spent more time with ‘patients’ affected by anxiety. The lack of information provided to those undergoing neuroimaging by the referring clinician regarding the possibility of discovering IFs was highlighted. Conclusion The impact of IFs upon the neurologist, ‘patient’ and the health institution appeared considerable. Further research determining the natural history of subclinical IFs and the efficacy of intervention will help to alleviate these issues. PMID:25723558

  5. Panic and the brainstem: clues from neuroimaging studies.

    PubMed

    Perna, Giampaolo; Guerriero, Giuseppe; Brambilla, Paolo; Caldirola, Daniela

    2014-01-01

    One of the most influential theories has conceived unexpected panic attack (PA) as a primal defensive reaction to threat within the internal milieu of the body. This theory is based on findings suggesting the involvement of dysfunctional respiratory regulation and/or abnormally sensitive central neural network of carbon dioxide (CO2)/hydrogen ion (H+) chemoreception in PA. Thus, unexpected PA may be related to phylogenetically older brain structures, including the brainstem areas, which process basic functions related to the organism's internal milieu. The brainstem represents a crucial area for homeostatic regulation, including chemoreception and cardio-respiratory control. In addition, the midbrain dorsal periaqueductal gray may be involved in the unconditioned defense reactions to proximal threats, including internal physical stimuli. Our aim was to specifically consider the potential involvement of the brainstem in panic disorder (PD) by a comprehensive review of the available neuroimaging studies. Available data are limited and potentially affected by several limitations. However, preliminary evidence of a role of the brainstem in PD can be found and, secondly, the brainstem serotonergic system seems to be involved in panic modulation with indications of both altered serotonergic receptors and 5-HT transporter bindings. In conclusion, our review suggests that the brainstem may be involved in psychopathology of PD and supports the relevant role of subcortical serotonergic system in panic pathogenesis. PMID:24923341

  6. Cerebral Microbleeds: A Review of Clinical, Genetic, and Neuroimaging Associations

    PubMed Central

    Yates, Paul A.; Villemagne, Victor L.; Ellis, Kathryn A.; Desmond, Patricia M.; Masters, Colin L.; Rowe, Christopher C.

    2013-01-01

    Cerebral microbleeds (microbleeds) are small, punctuate hypointense lesions seen in T2* Gradient-Recall Echo (GRE) and Susceptibility-Weighted (SWI) Magnetic Resonance Imaging (MRI) sequences, corresponding to areas of hemosiderin breakdown products from prior microscopic hemorrhages. They occur in the setting of impaired small vessel integrity, commonly due to either hypertensive vasculopathy or cerebral amyloid angiopathy. Microbleeds are more prevalent in individuals with Alzheimer’s disease (AD) dementia and in those with both ischemic and hemorrhagic stroke. However they are also found in asymptomatic individuals, with increasing prevalence with age, particularly in carriers of the Apolipoprotein (APOE) ε4 allele. Other neuroimaging findings that have been linked with microbleeds include lacunar infarcts and white matter hyperintensities on MRI, and increased cerebral β-amyloid burden using 11C-PiB Positron Emission Tomography. The presence of microbleeds has been suggested to confer increased risk of incident intracerebral hemorrhage – particularly in the setting of anticoagulation – and of complications of immunotherapy for AD. Prospective data regarding the natural history and sequelae of microbleeds are currently limited, however there is a growing evidence base that will serve to inform clinical decision-making in the future. PMID:24432010

  7. Functional neuroimaging of acute oculomotor deficits in concussed athletes.

    PubMed

    Johnson, Brian; Zhang, Kai; Hallett, Mark; Slobounov, Semyon

    2015-09-01

    In the pursuit to better understand the neural underpinnings of oculomotor deficits following concussion we performed a battery of oculomotor tests while performing simultaneous functional magnetic resonance imaging (fMRI). Based on the increasing evidence that concussion can disrupt multiple brain functional networks, including the oculomotor control networks, a series of classic saccadic and smooth pursuit tasks were implemented. Nine concussed athletes were tested within seven days of injury along with nine age and sex matched healthy normal volunteers. Both behavioral and fMRI data revealed differential results between the concussed and normal volunteer groups. Concussed subjects displayed longer latency time in the saccadic tasks, worse position errors, and fewer numbers of self-paced saccades compared to normal volunteer subjects. Furthermore, the concussed group showed recruitment of additional brain regions and larger activation sites as evidenced by fMRI. As a potential diagnostic and management tool for concussion, oculomotor testing shows promise, and here we try to understand the reasons for this disrupted performance with the aide of advanced neuroimaging tools. PMID:25179246

  8. Neuroimaging the temporal dynamics of human avoidance to sustained threat.

    PubMed

    Schlund, Michael W; Hudgins, Caleb D; Magee, Sandy; Dymond, Simon

    2013-11-15

    Many forms of human psychopathology are characterized by sustained negative emotional responses to threat and chronic behavioral avoidance, implicating avoidance as a potential transdiagnostic factor. Evidence from both nonhuman neurophysiological and human neuroimaging studies suggests a distributed frontal-limbic-striatal brain network supports avoidance. However, our understanding of the temporal dynamics of the network to sustained threat that prompts sustained avoidance is limited. To address this issue, 17 adults were given extensive training on a modified free-operant avoidance task in which button pressing avoided money loss during a sustained threat period. Subsequently, subjects underwent functional magnetic resonance imaging while completing the avoidance task. In our regions of interest, we observed phasic, rather than sustained, activation during sustained threat in dorsolateral and inferior frontal regions, anterior and dorsal cingulate, ventral striatum and regions associated with emotion, including the amygdala, insula, substantia nigra and bed nucleus of the stria terminalis complex. Moreover, trait levels of experiential avoidance were negatively correlated with insula, hippocampal and amygdala activation. These findings suggest knowledge that one can consistently avoid aversive outcomes is not associated with decreased threat-related responses and that individuals with greater experiential avoidance exhibit reduced reactivity to initial threat. Implications for understanding brain mechanisms supporting human avoidance and psychological theories of avoidance are discussed. PMID:24095880

  9. A Functional Approach to Deconvolve Dynamic Neuroimaging Data

    PubMed Central

    Jiang, Ci-Ren; Aston, John A. D.; Wang, Jane-Ling

    2016-01-01

    Positron emission tomography (PET) is an imaging technique which can be used to investigate chemical changes in human biological processes such as cancer development or neurochemical reactions. Most dynamic PET scans are currently analyzed based on the assumption that linear first-order kinetics can be used to adequately describe the system under observation. However, there has recently been strong evidence that this is not the case. To provide an analysis of PET data which is free from this compartmental assumption, we propose a nonparametric deconvolution and analysis model for dynamic PET data based on functional principal component analysis. This yields flexibility in the possible deconvolved functions while still performing well when a linear compartmental model setup is the true data generating mechanism. As the deconvolution needs to be performed on only a relative small number of basis functions rather than voxel by voxel in the entire three-dimensional volume, the methodology is both robust to typical brain imaging noise levels while also being computationally efficient. The new methodology is investigated through simulations in both one-dimensional functions and 2D images and also applied to a neuroimaging study whose goal is the quantification of opioid receptor concentration in the brain. PMID:27226673

  10. Inactivation of Ricin Toxin by Nanosecond Pulsed Electric Fields Including Evidences from Cell and Animal Toxicity

    NASA Astrophysics Data System (ADS)

    Wei, Kai; Li, Wei; Gao, Shan; Ji, Bin; Zang, Yating; Su, Bo; Wang, Kaile; Yao, Maosheng; Zhang, Jue; Wang, Jinglin

    2016-01-01

    Ricin is one of the most toxic and easily produced plant protein toxin extracted from the castor oil plant, and it has been classified as a chemical warfare agent. Here, nanosecond pulsed electric fields (nsPEFs) at 30 kV/cm (pulse durations: 10 ns, 100 ns, and 300 ns) were applied to inactivating ricin up to 4.2 μg/mL. To investigate the efficacy, cells and mice were tested against the ricin treated by the nsPEFs via direct intraperitoneal injection and inhalation exposure. Results showed that nsPEFs treatments can effectively reduce the toxicity of the ricin. Without the nsPEFs treatment, 100% of mice were killed upon the 4 μg ricin injection on the first day, however 40% of the mice survived the ricin treated by the nsPEFs. Compared to injection, inhalation exposure even with higher ricin dose required longer time to observe mice fatality. Pathological observations revealed damages to heart, lung, kidney, and stomach after the ricin exposure, more pronounced for lung and kidney including severe bleeding. Sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE) and circular dichroism (CD) analyses revealed that although the primary structure of ricin was not altered, its secondary structures (beta-sheet and beta-turn) underwent transition upon the nsPEFs treatment.

  11. Inactivation of Ricin Toxin by Nanosecond Pulsed Electric Fields Including Evidences from Cell and Animal Toxicity

    PubMed Central

    Wei, Kai; Li, Wei; Gao, Shan; Ji, Bin; Zang, Yating; Su, Bo; Wang, Kaile; Yao, Maosheng; Zhang, Jue; Wang, Jinglin

    2016-01-01

    Ricin is one of the most toxic and easily produced plant protein toxin extracted from the castor oil plant, and it has been classified as a chemical warfare agent. Here, nanosecond pulsed electric fields (nsPEFs) at 30 kV/cm (pulse durations: 10 ns, 100 ns, and 300 ns) were applied to inactivating ricin up to 4.2 μg/mL. To investigate the efficacy, cells and mice were tested against the ricin treated by the nsPEFs via direct intraperitoneal injection and inhalation exposure. Results showed that nsPEFs treatments can effectively reduce the toxicity of the ricin. Without the nsPEFs treatment, 100% of mice were killed upon the 4 μg ricin injection on the first day, however 40% of the mice survived the ricin treated by the nsPEFs. Compared to injection, inhalation exposure even with higher ricin dose required longer time to observe mice fatality. Pathological observations revealed damages to heart, lung, kidney, and stomach after the ricin exposure, more pronounced for lung and kidney including severe bleeding. Sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE) and circular dichroism (CD) analyses revealed that although the primary structure of ricin was not altered, its secondary structures (beta-sheet and beta-turn) underwent transition upon the nsPEFs treatment. PMID:26728251

  12. Evidence of nonclassical plasma transport in hollow cathodes for electric propulsion

    SciTech Connect

    Mikellides, Ioannis G.; Katz, Ira; Goebel, Dan M.; Jameson, Kristina K.

    2007-03-15

    Measurements, simplified analyses, and two-dimensional numerical simulations with a fluid plasma model show that classical resistivity cannot account for the elevated electron temperatures and steep plasma potential gradients measured in a 25-27.5 A electric propulsion hollow cathode. The cathode consisted of a 1.5 cm hollow tube with an {approx}0.28 cm diameter orifice and was operated with 5.5 SCCM (SCCM denotes cubic centimeter per minute at STP) of xenon flow using two different anode geometries: a segmented cone and a circular flat plate. The numerical simulations show that classical resistivity yields as much as four times colder electron temperatures compared to the measured values in the orifice and near-plume regions of the cathode. Classical transport and Ohm's law also predict exceedingly high electron-ion relative drift speeds compared to the electron thermal speed (>4). It is found that the addition of anomalous resistivity based on existing growth rate formulas for electron-ion streaming instabilities improves qualitatively the comparison between the numerical results and the time-averaged measurements. Simplified analyses that have been based largely on the axial measurements support the conclusion that additional resistivity is required in Ohm's law to explain the measurements. The combined results from the two-dimensional simulations and the analyses bound the range of enhanced resistivity to be 3-100 times the classical value.

  13. Inactivation of Ricin Toxin by Nanosecond Pulsed Electric Fields Including Evidences from Cell and Animal Toxicity.

    PubMed

    Wei, Kai; Li, Wei; Gao, Shan; Ji, Bin; Zang, Yating; Su, Bo; Wang, Kaile; Yao, Maosheng; Zhang, Jue; Wang, Jinglin

    2016-01-01

    Ricin is one of the most toxic and easily produced plant protein toxin extracted from the castor oil plant, and it has been classified as a chemical warfare agent. Here, nanosecond pulsed electric fields (nsPEFs) at 30 kV/cm (pulse durations: 10 ns, 100 ns, and 300 ns) were applied to inactivating ricin up to 4.2 μg/mL. To investigate the efficacy, cells and mice were tested against the ricin treated by the nsPEFs via direct intraperitoneal injection and inhalation exposure. Results showed that nsPEFs treatments can effectively reduce the toxicity of the ricin. Without the nsPEFs treatment, 100% of mice were killed upon the 4 μg ricin injection on the first day, however 40% of the mice survived the ricin treated by the nsPEFs. Compared to injection, inhalation exposure even with higher ricin dose required longer time to observe mice fatality. Pathological observations revealed damages to heart, lung, kidney, and stomach after the ricin exposure, more pronounced for lung and kidney including severe bleeding. Sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE) and circular dichroism (CD) analyses revealed that although the primary structure of ricin was not altered, its secondary structures (beta-sheet and beta-turn) underwent transition upon the nsPEFs treatment. PMID:26728251

  14. Functional Neuroimaging Abnormalities in Psychosis Spectrum Youth

    PubMed Central

    Wolf, Daniel H.; Satterthwaite, Theodore D.; Calkins, Monica E.; Ruparel, Kosha; Elliott, Mark A.; Hopson, Ryan D.; Jackson, Chad; Prabhakaran, Karthik; Bilker, Warren B.; Hakonarson, Hakon; Gur, Ruben C.; Gur, Raquel E.

    2015-01-01

    Importance The continuum view of the psychosis spectrum (PS) implies that in population-based samples, PS symptoms should be associated with neural abnormalities similar to those found in help-seeking clinical-risk individuals and in schizophrenia. Functional neuroimaging has not previously been applied in large population-based PS samples, and can help understand the neural architecture of psychosis more broadly, and identify brain phenotypes beyond symptomatology that are associated with the extended psychosis phenotype. Objective To examine the categorical and dimensional relationships of PS symptoms to prefrontal hypoactivation during working memory and to amygdala hyperactivation during threat emotion processing. Design The Philadelphia Neurodevelopmental Cohort (PNC) is a genotyped prospectively accrued population-based sample of nearly 10,000 youths, who received a structured psychiatric evaluation and a computerized neurocognitive battery. A subsample of 1,445 subjects underwent neuroimaging including functional magnetic resonance imaging (fMRI) tasks examined here. Setting The PNC is a collaboration between The Children’s Hospital of Philadelphia and the Hospital of the University of Pennsylvania. Participants Youths ages 11–22 years identified through structured interview as having psychosis-spectrum features (PS, n=260), and typically developing comparison subjects without significant psychopathology (TD, n=220). Main Outcomes and Measures Two fMRI paradigms were utilized, a fractal n-back working memory task probing executive system function, and an emotion identification task probing amygdala responses to threatening faces. Results In the n-back task, PS showed reduced activation in executive control circuitry, which correlated with cognitive deficits. During emotion identification, PS demonstrated elevated amygdala responses to threatening facial expressions, which correlated with positive symptom severity. Conclusions and Relevance The pattern of

  15. The Evolution of Neuroimaging Research and Developmental Language Disorders.

    ERIC Educational Resources Information Center

    Lane, Angela B.; Foundas, Anne L.; Leonard, Christiana M.

    2001-01-01

    This article reviews current neuroimaging literature, including computer tomography, positron emission tomography, single photon emission spectroscopy, and magnetic resonance imaging, on individuals with developmental language disorders. The review suggests a complicated relationship between cortical morphometry and language development that is…

  16. Terminology development towards harmonizing multiple clinical neuroimaging research repositories

    PubMed Central

    Turner, Jessica A.; Pasquerello, Danielle; Turner, Matthew D.; Keator, David B.; Alpert, Kathryn; King, Margaret; Landis, Drew; Calhoun, Vince D.; Potkin, Steven G.; Tallis, Marcelo; Ambite, Jose Luis; Wang, Lei

    2015-01-01

    Data sharing and mediation across disparate neuroimaging repositories requires extensive effort to ensure that the different domains of data types are referred to by commonly agreed upon terms. Within the SchizConnect project, which enables querying across decentralized databases of neuroimaging, clinical, and cognitive data from various studies of schizophrenia, we developed a model for each data domain, identified common usable terms that could be agreed upon across the repositories, and linked them to standard ontological terms where possible. We had the goal of facilitating both the current user experience in querying and future automated computations and reasoning regarding the data. We found that existing terminologies are incomplete for these purposes, even with the history of neuroimaging data sharing in the field; and we provide a model for efforts focused on querying multiple clinical neuroimaging repositories. PMID:26688838

  17. Auditory Neuroimaging with fMRI and PET

    PubMed Central

    Talavage, Thomas M.; Gonzalez-Castillo, Javier; Scott, Sophie K.

    2013-01-01

    For much of the past 30 years, investigations of auditory perception and language have been enhanced or even driven by the use of functional neuroimaging techniques that specialize in localization of central responses. Beginning with investigations using positron emission tomography (PET) and gradually shifting primarily to usage of functional magnetic resonance imaging (fMRI), auditory neuroimaging has greatly advanced our understanding of the organization and response properties of brain regions critical to the perception of and communication with the acoustic world in which we live. As the complexity of the questions being addressed has increased, the techniques, experiments and analyses applied have also become more nuanced and specialized. A brief review of the history of these investigations sets the stage for an overview and analysis of how these neuroimaging modalities are becoming ever more effective tools for understanding the auditory brain. We conclude with a brief discussion of open methodological issues as well as potential clinical applications for auditory neuroimaging. PMID:24076424

  18. [Neuroimaging findings in cerebroretinal microangiopathy with calcifications and cysts].

    PubMed

    Herrera, Diego Alberto; Vargas, Sergio Alberto; Montoya, Claudia

    2014-01-01

    Cerebroretinal microangiopathy with calcifications and cysts is a rare condition characterized by brain, retinal and bone anomalies, as well as a predisposition to gastrointestinal bleeding. There are few reported cases of this condition in adults, among whom the incidence is low. Neuroimaging findings are characteristic, with bilateral calcifications, leukoencephalopathy and intracranial cysts. The purpose of this article was to do a literature survey and illustrate two cases diagnosed with the aid of neuroimaging. PMID:24967922

  19. Human Neuroimaging as a “Big Data” Science

    PubMed Central

    Van Horn, John Darrell; Toga, Arthur W.

    2013-01-01

    The maturation of in vivo neuroimaging has lead to incredible quantities of digital information about the human brain. While much is made of the data deluge in science, neuroimaging represents the leading edge of this onslaught of “big data”. A range of neuroimaging databasing approaches has streamlined the transmission, storage, and dissemination of data from such brain imaging studies. Yet few, if any, common solutions exist to support the science of neuroimaging. In this article, we discuss how modern neuroimaging research represents a mutifactorial and broad ranging data challenge, involving the growing size of the data being acquired; sociologial and logistical sharing issues; infrastructural challenges for multi-site, multi-datatype archiving; and the means by which to explore and mine these data. As neuroimaging advances further, e.g. aging, genetics, and age-related disease, new vision is needed to manage and process this information while marshalling of these resources into novel results. Thus, “big data” can become “big” brain science. PMID:24113873

  20. Neuroimaging supports central pathology in familial dysautonomia.

    PubMed

    Axelrod, Felicia B; Hilz, Max J; Berlin, Dena; Yau, Po Lai; Javier, David; Sweat, Victoria; Bruehl, Hannah; Convit, Antonio

    2010-02-01

    Familial dysautonomia (FD) is a hereditary peripheral and central nervous system disorder with poorly defined central neuropathology. This prospective pilot study aimed to determine if MRI would provide objective parameters of central neuropathology. There were 14 study subjects, seven FD individuals (18.6 +/- 4.2 years, 3 female) and seven controls (19.1 +/- 5.8 years, 3 female). All subjects had standardized brain MRI evaluation including quantitative regional volume measurements, diffusion tensor imaging (DTI) for assessment of white matter (WM) microstructural integrity by calculation of fractional anisotropy (FA), and proton MR spectroscopy ((1)H MRS) to assess neuronal health. The FD patients had significantly decreased FA in optic radiation (p = 0.009) and middle cerebellar peduncle (p = 0.004). Voxel-wise analysis identified both GM and WM microstructural damage among FD subjects as there were nine clusters of WM FA reductions and 16 clusters of GM apparent diffusion coefficient (ADC) elevations. Their WM proportion was significantly decreased (p = 0.003) as was the WM proportion in the frontal region (p = 0.007). (1)H MRS showed no significant abnormalities. The findings of WM abnormalities and decreased optic radiation and middle cerebellar peduncle FA in the FD study group, suggest compromised myelination and WM micro-structural integrity in FD brains. These neuroimaging results are consistent with clinical visual abnormalities and gait disturbance. Furthermore the frontal lobe atrophy is consistent with previously reported neuropsychological deficits. PMID:19705052

  1. Early detection of Alzheimer's disease using neuroimaging.

    PubMed

    Mosconi, Lisa; Brys, Miroslaw; Glodzik-Sobanska, Lidia; De Santi, Susan; Rusinek, Henry; de Leon, Mony J

    2007-01-01

    Neuroimaging is being increasingly used to complement clinical assessments in the early detection of Alzheimer's disease (AD). Structural magnetic resonance imaging (MRI) and metabolic positron emission tomography (FDG-PET) are the most clinically used and promising modalities to detect brain abnormalities in individuals who might be at risk for AD but who have not yet developed symptoms. The knowledge of established risk factors for AD enabled investigators to develop enrichment strategies for longitudinal imaging studies to reduce the sample sizes and study duration. The present review focuses on the results obtained by MRI and FDG-PET studies that examined the preclinical AD stages in several at risk populations: (1) individuals from families with autosomal dominant early-onset AD (FAD), (2) patients with mild cognitive impairment (MCI), particularly in memory, who are at very high risk for declining to AD with an estimated decline rate of 10-30% per year, (3) normal young and middle-age subjects carriers of known susceptibility genes for late-onset AD such as the Apolipoprotein E (ApoE) E4 allele, and (4) as age is the main risk factor for AD, normal elderly individuals followed to the onset of MCI and AD. Overall, these studies show that the use of imaging for the early detection of AD is successful even in the earlier stages of disease when clinical symptoms are not fully expressed and the regional brain damage may be limited. PMID:16839732

  2. Sleep Neuroimaging and Models of Consciousness

    PubMed Central

    Tagliazucchi, Enzo; Behrens, Marion; Laufs, Helmut

    2013-01-01

    Human deep sleep is characterized by reduced sensory activity, responsiveness to stimuli, and conscious awareness. Given its ubiquity and reversible nature, it represents an attractive paradigm to study the neural changes which accompany the loss of consciousness in humans. In particular, the deepest stages of sleep can serve as an empirical test for the predictions of theoretical models relating the phenomenology of consciousness with underlying neural activity. A relatively recent shift of attention from the analysis of evoked responses toward spontaneous (or “resting state”) activity has taken place in the neuroimaging community, together with the development of tools suitable to study distributed functional interactions. In this review we focus on recent functional Magnetic Resonance Imaging (fMRI) studies of spontaneous activity during sleep and their relationship with theoretical models for human consciousness generation, considering the global workspace theory, the information integration theory, and the dynamical core hypothesis. We discuss the venues of research opened by these results, emphasizing the need to extend the analytic methodology in order to obtain a dynamical picture of how functional interactions change over time and how their evolution is modulated during different conscious states. Finally, we discuss the need to experimentally establish absent or reduced conscious content, even when studying the deepest sleep stages. PMID:23717291

  3. Challenges for Molecular Neuroimaging with MRI

    PubMed Central

    Lelyveld, Victor S.; Atanasijevic, Tatjana; Jasanoff, Alan

    2010-01-01

    Magnetic resonance (MRI)-based molecular imaging methods are beginning to have impact in neuroscience. A growing number of molecular imaging agents have been synthesized and tested in vitro, but so far relatively few have been validated in the brains of live animals. Here, we discuss key challenges associated with expanding the repertoire of successful molecular neuroimaging approaches. The difficulty of delivering agents past the blood-brain barrier (BBB) is a particular obstacle to molecular imaging in the central nervous system. We review established and emerging techniques for trans-BBB delivery, including intracranial infusion, BBB disruption, and transporter-related methods. Improving the sensitivity with which MRI-based molecular agents can be detected is a second major challenge. Better sensitivity would in turn reduce the requirements for delivery and alleviate potential side effects. We discuss recent efforts to enhance relaxivity of conventional longitudinal relaxation time (T1) and transverse relaxation time (T2) MRI contrast agents, as well as strategies that involve amplifying molecular signals or reducing endogenous background influences. With ongoing refinement of imaging approaches and brain delivery methods, MRI-based techniques for molecular-level neuroscientific investigation will fall increasingly within reach. PMID:20808721

  4. Neuroimaging studies in people with gender incongruence.

    PubMed

    Kreukels, Baudewijntje P C; Guillamon, Antonio

    2016-01-01

    The current review gives an overview of brain studies in transgender people. First, we describe studies into the aetiology of feelings of gender incongruence, primarily addressing the sexual differentiation hypothesis: does the brain of transgender individuals resemble that of their natal sex, or that of their experienced gender? Findings from neuroimaging studies focusing on brain structure suggest that the brain phenotypes of trans women (MtF) and trans men (FtM) differ in various ways from control men and women with feminine, masculine, demasculinized and defeminized features. The brain phenotypes of people with feelings of gender incongruence may help us to figure out whether sex differentiation of the brain is atypical in these individuals, and shed light on gender identity development. Task-related imaging studies may show whether brain activation and task performance in transgender people is sex-atypical. Second, we review studies that evaluate the effects of cross-sex hormone treatment on the brain. This type of research provides knowledge on how changes in sex hormone levels may affect brain structure and function. PMID:26766406

  5. Neuroimaging assessment of early and late neurobiological sequelae of traumatic brain injury: implications for CTE

    PubMed Central

    Sundman, Mark; Doraiswamy, P. Murali; Morey, Rajendra A.

    2015-01-01

    Traumatic brain injury (TBI) has been increasingly accepted as a major external risk factor for neurodegenerative morbidity and mortality. Recent evidence indicates that the resultant chronic neurobiological sequelae following head trauma may, at least in part, contribute to a pathologically distinct disease known as Chronic Traumatic Encephalopathy (CTE). The clinical manifestation of CTE is variable, but the symptoms of this progressive disease include impaired memory and cognition, affective disorders (i.e., impulsivity, aggression, depression, suicidality, etc.), and diminished motor control. Notably, mounting evidence suggests that the pathology contributing to CTE may be caused by repetitive exposure to subconcussive hits to the head, even in those with no history of a clinically evident head injury. Given the millions of athletes and military personnel with potential exposure to repetitive subconcussive insults and TBI, CTE represents an important public health issue. However, the incidence rates and pathological mechanisms are still largely unknown, primarily due to the fact that there is no in vivo diagnostic tool. The primary objective of this manuscript is to address this limitation and discuss potential neuroimaging modalities that may be capable of diagnosing CTE in vivo through the detection of tau and other known pathological features. Additionally, we will discuss the challenges of TBI research, outline the known pathology of CTE (with an emphasis on Tau), review current neuroimaging modalities to assess the potential routes for in vivo diagnosis, and discuss the future directions of CTE research. PMID:26441507

  6. Neuroimaging characteristics of dementia with Lewy bodies.

    PubMed

    Mak, Elijah; Su, Li; Williams, Guy B; O'Brien, John T

    2014-01-01

    This review summarises the findings and applications from neuroimaging studies in dementia with Lewy bodies (DLB), highlighting key differences between DLB and other subtypes of dementia. We also discuss the increasingly important role of imaging biomarkers in differential diagnosis and outline promising areas for future research in DLB. DLB shares common clinical, neuropsychological and pathological features with Parkinson's disease dementia and other dementia subtypes, such as Alzheimer's disease. Despite the development of consensus diagnostic criteria, the sensitivity for differential diagnosis of DLB in clinical practice remains low and many DLB patients will be misdiagnosed. The importance of developing accurate imaging markers in dementia is highlighted by the potential for treatments targeting specific molecular abnormalities as well as the responsiveness to cholinesterase inhibitors and marked neuroleptic sensitivity of DLB. We review various brain imaging techniques that have been applied to investigate DLB, including the characteristic nigrostriatal degeneration in DLB using positron emission tomography (PET) and single-photon emission computed tomography (SPECT) tracers. Dopamine transporter loss has proven to reliably differentiate DLB from other dementias and has been incorporated into the revised clinical diagnostic criteria for DLB. To date, this remains the 'gold standard' for diagnostic imaging of DLB. Regional cerebral blood flow, 18 F-fluorodeoxygluclose-PET and SPECT have also identified marked deficits in the occipital regions with relative sparing of the medial temporal lobe when compared to Alzheimer's disease. In addition, structural, diffusion, and functional magnetic resonance imaging techniques have shown alterations in structure, white matter integrity, and functional activity in DLB. We argue that the multimodal identification of DLB-specific biomarkers has the potential to improve ante-mortem diagnosis and contribute to our

  7. The human parental brain: In vivo neuroimaging

    PubMed Central

    Swain, James E.

    2015-01-01

    Interacting parenting thoughts and behaviors, supported by key brain circuits, critically shape human infants’ current and future behavior. Indeed, the parent–infant relationship provides infants with their first social environment, forming templates for what they can expect from others, how to interact with them and ultimately how they go on to themselves to be parents. This review concentrates on magnetic resonance imaging experiments of the human parent brain, which link brain physiology with parental thoughts and behaviors. After reviewing brain imaging techniques, certain social cognitive and affective concepts are reviewed, including empathy and trust—likely critical to parenting. Following that is a thorough study-by-study review of the state-of-the-art with respect to human neuroimaging studies of the parental brain—from parent brain responses to salient infant stimuli, including emotionally charged baby cries and brief visual stimuli to the latest structural brain studies. Taken together, this research suggests that networks of highly conserved hypothalamic–midbrain–limbic–paralimbic–cortical circuits act in concert to support parental brain responses to infants, including circuits for limbic emotion response and regulation. Thus, a model is presented in which infant stimuli activate sensory analysis brain regions, affect corticolimbic limbic circuits that regulate emotional response, motivation and reward related to their infant, ultimately organizing parenting impulses, thoughts and emotions into coordinated behaviors as a map for future studies. Finally, future directions towards integrated understanding of the brain basis of human parenting are outlined with profound implications for understanding and contributing to long term parent and infant mental health. PMID:21036196

  8. Analyzing neuroimaging data with subclasses: A shrinkage approach.

    PubMed

    Höhne, Johannes; Bartz, Daniel; Hebart, Martin N; Müller, Klaus-Robert; Blankertz, Benjamin

    2016-01-01

    Among the numerous methods used to analyze neuroimaging data, Linear Discriminant Analysis (LDA) is commonly applied for binary classification problems. LDAs popularity derives from its simplicity and its competitive classification performance, which has been reported for various types of neuroimaging data. Yet the standard LDA approach proves less than optimal for binary classification problems when additional label information (i.e. subclass labels) is present. Subclass labels allow to model structure in the data, which can be used to facilitate the classification task. In this paper, we illustrate how neuroimaging data exhibit subclass labels that may contain valuable information. We also show that the standard LDA classifier is unable to exploit subclass labels. We introduce a novel method that allows subclass labels to be incorporated efficiently into the classifier. The novel method, which we call Relevance Subclass LDA (RSLDA), computes an individual classification hyperplane for each subclass. It is based on regularized estimators of the subclass mean and uses other subclasses as regularization targets. We demonstrate the applicability and performance of our method on data drawn from two different neuroimaging modalities: (I) EEG data from brain-computer interfacing with event-related potentials, and (II) fMRI data in response to different levels of visual motion. We show that RSLDA outperforms the standard LDA approach for both types of datasets. These findings illustrate the benefits of exploiting subclass structure in neuroimaging data. Finally, we show that our classifier also outputs regularization profiles, enabling researchers to interpret the subclass structure in a meaningful way. RSLDA therefore yields increased classification accuracy as well as a better interpretation of neuroimaging data. Since both results are highly favorable, we suggest to apply RSLDA for various classification problems within neuroimaging and beyond. PMID:26407815

  9. Environmental impact of electric motorcycles: Evidence from traffic noise assessment by a building-based data mining technique.

    PubMed

    Sheng, N; Zhou, X; Zhou, Y

    2016-06-01

    This study provided new evidence on the potential adoption of electric motorcycle (EM) as a cleaner alternative to gasoline-powered motorcycle. The effects of EM on human exposure to traffic noise were assessed in different urban areas with different traffic scenarios. The assessment was carried out by a developed building-based model system that took into account the contribution of motorcycle traffic. The results indicated that the EM could be an appealing solution to reduce the risk of human exposure to excessive high traffic noise in a motorcycle city. Particularly, in a historical urban area in which the total traffic volume was lower and motorcycle traffic was dominant, the proportion of noise levels meeting the standard of 70 dB(A) increased significantly from 12.2% to 41.9% when 100% of gasoline motorcycles in the real traffic scenario were replaced by EMs. On the other hand, in a modern urban area in which the total traffic volume was higher and traffic noise levels at majority of sites were higher than 75 dB(A), the proportion of noise levels above 75 dB(A) decreased significantly from 82.6% to 59.9%. Nevertheless, the effect of EM on improving the traffic noise compliance rate in the modern urban area was not significant and other policies or measures need to be sought. PMID:26950621

  10. Functional neuroimaging of traumatic brain injury: advances and clinical utility

    PubMed Central

    Irimia, Andrei; Van Horn, John Darrell

    2015-01-01

    Functional deficits due to traumatic brain injury (TBI) can have significant and enduring consequences upon patients’ life quality and expectancy. Although functional neuroimaging is essential for understanding TBI pathophysiology, an insufficient amount of effort has been dedicated to the task of translating functional neuroimaging findings into information with clinical utility. The purpose of this review is to summarize the use of functional neuroimaging techniques – especially functional magnetic resonance imaging, diffusion tensor imaging, positron emission tomography, magnetic resonance spectroscopy, and electroencephalography – for advancing current knowledge of TBI-related brain dysfunction and for improving the rehabilitation of TBI patients. We focus on seven core areas of functional deficits, namely consciousness, motor function, attention, memory, higher cognition, personality, and affect, and, for each of these, we summarize recent findings from neuroimaging studies which have provided substantial insight into brain function changes due to TBI. Recommendations are also provided to aid in setting the direction of future neuroimaging research and for understanding brain function changes after TBI. PMID:26396520

  11. The Co-evolution of Neuroimaging and Psychiatric Neurosurgery.

    PubMed

    Dyster, Timothy G; Mikell, Charles B; Sheth, Sameer A

    2016-01-01

    The role of neuroimaging in psychiatric neurosurgery has evolved significantly throughout the field's history. Psychiatric neurosurgery initially developed without the benefit of information provided by modern imaging modalities, and thus lesion targets were selected based on contemporary theories of frontal lobe dysfunction in psychiatric disease. However, by the end of the 20th century, the availability of structural and functional magnetic resonance imaging (fMRI) allowed for the development of mechanistic theories attempting to explain the anatamofunctional basis of these disorders, as well as the efficacy of stereotactic neuromodulatory treatments. Neuroimaging now plays a central and ever-expanding role in the neurosurgical management of psychiatric disorders, by influencing the determination of surgical candidates, allowing individualized surgical targeting and planning, and identifying network-level changes in the brain following surgery. In this review, we aim to describe the coevolution of psychiatric neurosurgery and neuroimaging, including ways in which neuroimaging has proved useful in elucidating the therapeutic mechanisms of neuromodulatory procedures. We focus on ablative over stimulation-based procedures given their historical precedence and the greater opportunity they afford for post-operative re-imaging, but also discuss important contributions from the deep brain stimulation (DBS) literature. We conclude with a discussion of how neuroimaging will transition the field of psychiatric neurosurgery into the era of precision medicine. PMID:27445706

  12. The Co-evolution of Neuroimaging and Psychiatric Neurosurgery

    PubMed Central

    Dyster, Timothy G.; Mikell, Charles B.; Sheth, Sameer A.

    2016-01-01

    The role of neuroimaging in psychiatric neurosurgery has evolved significantly throughout the field’s history. Psychiatric neurosurgery initially developed without the benefit of information provided by modern imaging modalities, and thus lesion targets were selected based on contemporary theories of frontal lobe dysfunction in psychiatric disease. However, by the end of the 20th century, the availability of structural and functional magnetic resonance imaging (fMRI) allowed for the development of mechanistic theories attempting to explain the anatamofunctional basis of these disorders, as well as the efficacy of stereotactic neuromodulatory treatments. Neuroimaging now plays a central and ever-expanding role in the neurosurgical management of psychiatric disorders, by influencing the determination of surgical candidates, allowing individualized surgical targeting and planning, and identifying network-level changes in the brain following surgery. In this review, we aim to describe the coevolution of psychiatric neurosurgery and neuroimaging, including ways in which neuroimaging has proved useful in elucidating the therapeutic mechanisms of neuromodulatory procedures. We focus on ablative over stimulation-based procedures given their historical precedence and the greater opportunity they afford for post-operative re-imaging, but also discuss important contributions from the deep brain stimulation (DBS) literature. We conclude with a discussion of how neuroimaging will transition the field of psychiatric neurosurgery into the era of precision medicine. PMID:27445706

  13. Neuroimaging in mental health care: voices in translation

    PubMed Central

    Borgelt, Emily L.; Buchman, Daniel Z.; Illes, Judy

    2012-01-01

    Images of brain function, popularly called “neuroimages,” have become a mainstay of contemporary communication about neuroscience and mental health. Paralleling media coverage of neuroimaging research and the high visibility of clinics selling scans is pressure from sponsors to move basic research about brain function along the translational pathway. Indeed, neuroimaging may offer benefits to mental health care: early or tailored intervention, opportunities for education and planning, and access to resources afforded by objectification of disorder. However, risks of premature technology transfer, such as misinterpretation, misrepresentation, and increased stigmatization, could compromise patient care. The insights of stakeholder groups about neuroimaging for mental health care are a largely untapped resource of information and guidance for translational efforts. We argue that the insights of key stakeholders—including researchers, healthcare providers, patients, and families—have an essential role to play upstream in professional, critical, and ethical discourse surrounding neuroimaging in mental health. Here we integrate previously orthogonal lines of inquiry involving stakeholder research to describe the translational landscape as well as challenges on its horizon. PMID:23097640

  14. Functional neuroimaging studies of the effects of psychotherapy.

    PubMed

    Beauregard, Mario

    2014-03-01

    It has been long established that psychological interventions can markedly alter patients' thinking patterns, beliefs, attitudes, emotional states, and behaviors. Little was known about the neural mechanisms mediating such alterations before the advent of functional neuroimaging techniques. Since the turn of the new millenium, several functional neuroimaging studies have been conducted to tackle this important issue. Some of these studies have explored the neural impact of various forms of psychotherapy in individuals with major depressive disorder. Other neuroimaging studies have investigated the effects of psychological interventions for anxiety disorders. I review these studies in the present article, and discuss the putative neural mechanisms of change in psychotherapy. The findings of these studies suggest that mental and behavioral changes occurring during psychotherapeutic interventions can lead to a normalization of functional brain activity at a global level. PMID:24733972

  15. Multiple testing for neuroimaging via hidden Markov random field.

    PubMed

    Shu, Hai; Nan, Bin; Koeppe, Robert

    2015-09-01

    Traditional voxel-level multiple testing procedures in neuroimaging, mostly p-value based, often ignore the spatial correlations among neighboring voxels and thus suffer from substantial loss of power. We extend the local-significance-index based procedure originally developed for the hidden Markov chain models, which aims to minimize the false nondiscovery rate subject to a constraint on the false discovery rate, to three-dimensional neuroimaging data using a hidden Markov random field model. A generalized expectation-maximization algorithm for maximizing the penalized likelihood is proposed for estimating the model parameters. Extensive simulations show that the proposed approach is more powerful than conventional false discovery rate procedures. We apply the method to the comparison between mild cognitive impairment, a disease status with increased risk of developing Alzheimer's or another dementia, and normal controls in the FDG-PET imaging study of the Alzheimer's Disease Neuroimaging Initiative. PMID:26012881

  16. Functional neuroimaging studies of the effects of psychotherapy

    PubMed Central

    Beauregard, Mario

    2014-01-01

    It has been long established that psychological interventions can markedly alter patients' thinking patterns, beliefs, attitudes, emotional states, and behaviors. Little was known about the neural mechanisms mediating such alterations before the advent of functional neuroimaging techniques. Since the turn of the new millenium, several functional neuroimaging studies have been conducted to tackle this important issue. Some of these studies have explored the neural impact of various forms of psychotherapy in individuals with major depressive disorder. Other neuroimaging studies have investigated the effects of psychological interventions for anxiety disorders. I review these studies in the present article, and discuss the putative neural mechanisms of change in psychotherapy. The findings of these studies suggest that mental and behavioral changes occurring during psychotherapeutic interventions can lead to a normalization of functional brain activity at a global level. PMID:24733972

  17. Neuroimaging data sharing on the neuroinformatics database platform.

    PubMed

    Book, Gregory A; Stevens, Michael C; Assaf, Michal; Glahn, David C; Pearlson, Godfrey D

    2016-01-01

    We describe the Neuroinformatics Database (NiDB), an open-source database platform for archiving, analysis, and sharing of neuroimaging data. Data from the multi-site projects Autism Brain Imaging Data Exchange (ABIDE), Bipolar-Schizophrenia Network on Intermediate Phenotypes parts one and two (B-SNIP1, B-SNIP2), and Monetary Incentive Delay task (MID) are available for download from the public instance of NiDB, with more projects sharing data as it becomes available. As demonstrated by making several large datasets available, NiDB is an extensible platform appropriately suited to archive and distribute shared neuroimaging data. PMID:25888923

  18. Neuroimaging the interaction of mind and metabolism in humans

    PubMed Central

    D’Agostino, Alexandra E.; Small, Dana M.

    2012-01-01

    Hormonal and metabolic signals interact with neural circuits orchestrating behavior to guide food intake. Neuroimaging techniques such as functional magnetic resonance imaging (fMRI) enable the identification of where in the brain particular mental processes like desire, satiety and pleasure occur. Once these neural circuits are described it then becomes possible to determine how metabolic and hormonal signals can alter brain response to influence psychological states and decision-making processes to guide intake. Here, we provide an overview of the contributions of functional neuroimaging to the understanding of how subjective and neural responses to food and food cues interact with metabolic/hormonal factors. PMID:24024114

  19. 3D surface analysis and classification in neuroimaging segmentation.

    PubMed

    Zagar, Martin; Mlinarić, Hrvoje; Knezović, Josip

    2011-06-01

    This work emphasizes new algorithms for 3D edge and corner detection used in surface extraction and new concept of image segmentation in neuroimaging based on multidimensional shape analysis and classification. We propose using of NifTI standard for describing input data which enables interoperability and enhancement of existing computing tools used widely in neuroimaging research. In methods section we present our newly developed algorithm for 3D edge and corner detection, together with the algorithm for estimating local 3D shape. Surface of estimated shape is analyzed and segmented according to kernel shapes. PMID:21755723

  20. Neuroimaging of Semantic Processing in Schizophrenia: A Parametric Priming Approach

    PubMed Central

    Han, S. Duke; Wible, Cynthia G.

    2009-01-01

    The use of fMRI and other neuroimaging techniques in the study of cognitive language processes in psychiatric and non-psychiatric conditions has led at times to discrepant findings. Many issues complicate the study of language, especially in psychiatric populations. For example, the use of subtractive designs can produce misleading results. We propose and advocate for a semantic priming parametric approach to the study of semantic processing using fMRI methodology. Implications of this parametric approach are discussed in view of current functional neuroimaging research investigating the semantic processing disturbance of schizophrenia. PMID:19765623

  1. The use of functional neuroimaging to evaluate psychological and other non-pharmacological treatments for clinical pain.

    PubMed

    Jensen, Karin B; Berna, Chantal; Loggia, Marco L; Wasan, Ajay D; Edwards, Robert R; Gollub, Randy L

    2012-06-29

    A large number of studies have provided evidence for the efficacy of psychological and other non-pharmacological interventions in the treatment of chronic pain. While these methods are increasingly used to treat pain, remarkably few studies focused on the exploration of their neural correlates. The aim of this article was to review the findings from neuroimaging studies that evaluated the neural response to distraction-based techniques, cognitive behavioral therapy (CBT), clinical hypnosis, mental imagery, physical therapy/exercise, biofeedback, and mirror therapy. To date, the results from studies that used neuroimaging to evaluate these methods have not been conclusive and the experimental methods have been suboptimal for assessing clinical pain. Still, several different psychological and non-pharmacological treatment modalities were associated with increased pain-related activations of executive cognitive brain regions, such as the ventral- and dorsolateral prefrontal cortex. There was also evidence for decreased pain-related activations in afferent pain regions and limbic structures. If future studies will address the technical and methodological challenges of today's experiments, neuroimaging might have the potential of segregating the neural mechanisms of different treatment interventions and elucidate predictive and mediating factors for successful treatment outcomes. Evaluations of treatment-related brain changes (functional and structural) might also allow for sub-grouping of patients and help to develop individualized treatments. PMID:22445888

  2. Emotionally Neutral Stimuli Are Not Neutral in Schizophrenia: A Mini Review of Functional Neuroimaging Studies.

    PubMed

    Potvin, Stéphane; Tikàsz, Andràs; Mendrek, Adrianna

    2016-01-01

    Reliable evidence shows that schizophrenia patients tend to experience negative emotions when presented with emotionally neutral stimuli. Similarly, several functional neuroimaging studies show that schizophrenia patients have increased activations in response to neutral material. However, results are heterogeneous. Here, we review the functional neuroimaging studies that have addressed this research question. Based on the 36 functional neuroimaging studies that we retrieved, it seems that the increased brain reactivity to neutral stimuli is fairly common in schizophrenia, but that the regions involved vary considerably, apart from the amygdala. Prefrontal and cingulate sub-regions and the hippocampus may also be involved. By contrasts, results in individuals at risk for psychosis are less consistent. In schizophrenia patients, results are less consistent in the case of studies using non-facial stimuli, explicit processing paradigms, and/or event-related designs. This means that human faces may convey subtle information (e.g., trustworthiness) other than basic emotional expressions. It also means that the aberrant brain reactivity to neutral stimuli is less likely to occur when experimental paradigms are too cognitively demanding as well as in studies lacking statistical power. The main hypothesis proposed to account for this increased brain reactivity to neutral stimuli is the aberrant salience hypothesis of psychosis. Other investigators propose that the aberrant brain reactivity to neutral stimuli in schizophrenia results from abnormal associative learning, untrustworthiness judgments, priming effects, and/or reduced habituation to neutral stimuli. In the future, the effects of antipsychotics on this aberrant brain reactivity will need to be determined, as well as the potential implication of sex/gender. PMID:27445871

  3. Impact of Common Variations in PLD3 on Neuroimaging Phenotypes in Non-demented Elders.

    PubMed

    Wang, Chong; Wang, Hui-Fu; Tan, Meng-Shan; Liu, Ying; Jiang, Teng; Zhang, Dao-Qiang; Tan, Lan; Yu, Jin-Tai

    2016-09-01

    Rare variants of phospholipase D3 (PLD3) have been identified as Alzheimer's disease (AD) susceptibility loci, whereas little is known about the potential role of common variants in the progression of AD. To examine the impact of genetic variations in PLD3 on neuroimaging phenotypes in a large non-demented population. A total of 261 normal cognition (NC) and 456 mild cognitive impairment (MCI) individuals from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database are included in our analysis. Multiple linear regression models were applied to examine the association between four single-nucleotide polymorphisms (SNPs; rs7249146, rs4490097, rs12151243, and rs10407447) with the florbetapir retention on florbetapir 18F amyloid positron emission tomography (AV45-PET), the cerebral metabolic rate for glucose (CMRgl) on 18F-fluorodeoxyglucose PET (FDG-PET), and regional volume on magnetic resonance imaging (MRI) at baseline and in the cohort study. We did not detect any significant associations of PLD3 SNPs with florbetapir retention on AV45-PET. In the analysis of FDG-PET, rs10407447 was associated with the CMRgl in the left angular gyrus and bilateral posterior cingulate cortex in the MCI group. Regarding the MRI analysis, rs10407447 was also associated with bilateral inferior lateral ventricle and lateral ventricle volume in MCI group. The main findings of our study provide evidence that support the possible role of PLD3 common variants in influencing AD-related neuroimaging phenotypes. Nevertheless, further work is necessary to explain the functional mechanisms of differences and confirm the causal variants. PMID:26232066

  4. Emotionally Neutral Stimuli Are Not Neutral in Schizophrenia: A Mini Review of Functional Neuroimaging Studies

    PubMed Central

    Potvin, Stéphane; Tikàsz, Andràs; Mendrek, Adrianna

    2016-01-01

    Reliable evidence shows that schizophrenia patients tend to experience negative emotions when presented with emotionally neutral stimuli. Similarly, several functional neuroimaging studies show that schizophrenia patients have increased activations in response to neutral material. However, results are heterogeneous. Here, we review the functional neuroimaging studies that have addressed this research question. Based on the 36 functional neuroimaging studies that we retrieved, it seems that the increased brain reactivity to neutral stimuli is fairly common in schizophrenia, but that the regions involved vary considerably, apart from the amygdala. Prefrontal and cingulate sub-regions and the hippocampus may also be involved. By contrasts, results in individuals at risk for psychosis are less consistent. In schizophrenia patients, results are less consistent in the case of studies using non-facial stimuli, explicit processing paradigms, and/or event-related designs. This means that human faces may convey subtle information (e.g., trustworthiness) other than basic emotional expressions. It also means that the aberrant brain reactivity to neutral stimuli is less likely to occur when experimental paradigms are too cognitively demanding as well as in studies lacking statistical power. The main hypothesis proposed to account for this increased brain reactivity to neutral stimuli is the aberrant salience hypothesis of psychosis. Other investigators propose that the aberrant brain reactivity to neutral stimuli in schizophrenia results from abnormal associative learning, untrustworthiness judgments, priming effects, and/or reduced habituation to neutral stimuli. In the future, the effects of antipsychotics on this aberrant brain reactivity will need to be determined, as well as the potential implication of sex/gender. PMID:27445871

  5. Neuroimaging of frontal-limbic dysfunction in schizophrenia and epilepsy-related psychosis: toward a convergent neurobiology.

    PubMed

    Butler, Tracy; Weisholtz, Daniel; Isenberg, Nancy; Harding, Elizabeth; Epstein, Jane; Stern, Emily; Silbersweig, David

    2012-02-01

    Psychosis is a devastating, prevalent condition considered to involve dysfunction of frontal and medial temporal limbic brain regions as key nodes in distributed brain networks involved in emotional regulation. The psychoses of epilepsy represent an important, though understudied, model relevant to understanding the pathophysiology of psychosis in general. In this review, we (1) discuss the classification of epilepsy-related psychoses and relevant neuroimaging and other studies; (2) review structural and functional neuroimaging studies of schizophrenia focusing on evidence of frontal-limbic dysfunction; (3) report our laboratory's PET, fMRI, and electrophysiological findings; (4) describe a theoretical framework in which frontal hypoactivity and intermittent medial temporal hyperactivity play a critical role in the etiopathology of psychosis both associated and unassociated with epilepsy; and (5) suggest avenues for future research. PMID:22209327

  6. The Role of Functional Neuroimaging in Pre-Surgical Epilepsy Evaluation

    PubMed Central

    Pittau, Francesca; Grouiller, Frédéric; Spinelli, Laurent; Seeck, Margitta; Michel, Christoph M.; Vulliemoz, Serge

    2014-01-01

    The prevalence of epilepsy is about 1% and one-third of cases do not respond to medical treatment. In an eligible subset of patients with drug-resistant epilepsy, surgical resection of the epileptogenic zone is the only treatment that can possibly cure the disease. Non-invasive techniques provide information for the localization of the epileptic focus in the majority of cases, whereas in others invasive procedures are required. In the last years, non-invasive neuroimaging techniques, such as simultaneous recording of functional magnetic resonance imaging and electroencephalogram (EEG-fMRI), positron emission tomography (PET), single photon emission computed tomography (SPECT), electric and magnetic source imaging (MSI, ESI), spectroscopy (MRS), have proved their usefulness in defining the epileptic focus. The combination of these functional techniques can yield complementary information and their concordance is crucial for guiding clinical decision, namely the planning of invasive EEG recordings or respective surgery. The aim of this review is to present these non-invasive neuroimaging techniques, their potential combination, and their role in the pre-surgical evaluation of patients with pharmaco-resistant epilepsy. PMID:24715886

  7. Neuroimaging: A Window to the Neurological Foundations of Learning and Behavior in Children.

    ERIC Educational Resources Information Center

    Lyon, G. Reid, Ed.; Rumsey, Judith M., Ed.

    This book presents 11 papers on the use of neuroimaging technology in brain-related disorders. The text contains full-color neuroimaging scans and provides both theoretical and methodological explanations of the various neuroimaging techniques and their application to developmental disorders in children. The papers are grouped into three sections,…

  8. The Bilingual Brain as Revealed by Functional Neuroimaging.

    ERIC Educational Resources Information Center

    Abutalebi, Jubin; Cappa, Stefano F.; Perani, Daniela

    2001-01-01

    Functional neuroimaging of bilinguals and monolinguals used in conjunction with experimental cognitive tasks has been successful in establishing functional specialization as a principle of brain organization in humans. Consistent results show that attained proficiency and possibly language exposure are more important than age of acquisition as a…

  9. Uncovering the etiology of conversion disorder: insights from functional neuroimaging

    PubMed Central

    Ejareh dar, Maryam; Kanaan, Richard AA

    2016-01-01

    Conversion disorder (CD) is a syndrome of neurological symptoms arising without organic cause, arguably in response to emotional stress, but the exact neural substrates of these symptoms and the underlying mechanisms remain poorly understood with the hunt for a biological basis afoot for centuries. In the past 15 years, novel insights have been gained with the advent of functional neuroimaging studies in patients suffering from CDs in both motor and nonmotor domains. This review summarizes recent functional neuroimaging studies including functional magnetic resonance imaging (fMRI), single photon emission computerized tomography (SPECT), and positron emission tomography (PET) to see whether they bring us closer to understanding the etiology of CD. Convergent functional neuroimaging findings suggest alterations in brain circuits that could point to different mechanisms for manifesting functional neurological symptoms, in contrast with feigning or healthy controls. Abnormalities in emotion processing and in emotion-motor processing suggest a diathesis, while differential reactions to certain stressors implicate a specific response to trauma. No comprehensive theory emerges from these clues, and all results remain preliminary, but functional neuroimaging has at least given grounds for hope that a model for CD may soon be found. PMID:26834476

  10. Diagnostic and therapeutic utility of neuroimaging in depression: an overview

    PubMed Central

    Wise, Toby; Cleare, Anthony J; Herane, Andrés; Young, Allan H; Arnone, Danilo

    2014-01-01

    A growing number of studies have used neuroimaging to further our understanding of how brain structure and function are altered in major depression. More recently, these techniques have begun to show promise for the diagnosis and treatment of depression, both as aids to conventional methods and as methods in their own right. In this review, we describe recent neuroimaging findings in the field that might aid diagnosis and improve treatment accuracy. Overall, major depression is associated with numerous structural and functional differences in neural systems involved in emotion processing and mood regulation. Furthermore, several studies have shown that the structure and function of these systems is changed by pharmacological and psychological treatments of the condition and that these changes in candidate brain regions might predict clinical response. More recently, “machine learning” methods have used neuroimaging data to categorize individual patients according to their diagnostic status and predict treatment response. Despite being mostly limited to group-level comparisons at present, with the introduction of new methods and more naturalistic studies, neuroimaging has the potential to become part of the clinical armamentarium and may improve diagnostic accuracy and inform treatment choice at the patient level. PMID:25187715

  11. Diagnostic and therapeutic utility of neuroimaging in depression: an overview.

    PubMed

    Wise, Toby; Cleare, Anthony J; Herane, Andrés; Young, Allan H; Arnone, Danilo

    2014-01-01

    A growing number of studies have used neuroimaging to further our understanding of how brain structure and function are altered in major depression. More recently, these techniques have begun to show promise for the diagnosis and treatment of depression, both as aids to conventional methods and as methods in their own right. In this review, we describe recent neuroimaging findings in the field that might aid diagnosis and improve treatment accuracy. Overall, major depression is associated with numerous structural and functional differences in neural systems involved in emotion processing and mood regulation. Furthermore, several studies have shown that the structure and function of these systems is changed by pharmacological and psychological treatments of the condition and that these changes in candidate brain regions might predict clinical response. More recently, "machine learning" methods have used neuroimaging data to categorize individual patients according to their diagnostic status and predict treatment response. Despite being mostly limited to group-level comparisons at present, with the introduction of new methods and more naturalistic studies, neuroimaging has the potential to become part of the clinical armamentarium and may improve diagnostic accuracy and inform treatment choice at the patient level. PMID:25187715

  12. Epilogue: Neuroimaging with a View to Prediction and Prognosis.

    ERIC Educational Resources Information Center

    Kendall, Diane L.; Rothi, Leslie J. Gonzalez

    2001-01-01

    This epilogue discusses potentials in future clinical decision-making using the emerging functional neuroimaging technology, including identification of the mechanisms underlying cognitive functions and prediction of spared/impaired cognitive functions, those related to recovery of function and prediction of treatment candidacy; and those related…

  13. Neuroimaging Research with Children: Ethical Issues and Case Scenarios

    ERIC Educational Resources Information Center

    Coch, Donna

    2007-01-01

    There are few available resources for learning and teaching about ethical issues in neuroimaging research with children, who constitute a special and vulnerable population. Here, a brief review of ethical issues in developmental research, situated within the emerging field of neuroethics, highlights the increasingly interdisciplinary nature of…

  14. Neuroimaging of the Periaqueductal Gray: State of the Field

    PubMed Central

    Linnman, Clas; Moulton, Eric A.; Barmettler, Gabi; Becerra, Lino; Borsook, David

    2011-01-01

    This review and meta-analysis aims at summarizing and integrating the human neuroimaging studies that report periaqueductal gray (PAG) involvement; 250 original manuscripts on human neuroimaging of the PAG were identified. A narrative review and meta-analysis using activation likelihood estimates is included. Behaviors covered include pain and pain modulation, anxiety, bladder and bowel function and autonomic regulation. Methods include structural and functional magnetic resonance imaging, functional connectivity measures, diffusion weighted imaging and positron emission tomography. Human neuroimaging studies in healthy and clinical populations largely confirm the animal literature indicating that the PAG is involved in homeostatic regulation of salient functions such as pain, anxiety and autonomic function. Methodological concerns in the current literature, including resolution constraints, imaging artifacts and imprecise neuroanatomical labeling are discussed, and future directions are proposed. A general conclusion is that PAG neuroimaging is a field with enormous potential to translate animal data onto human behaviors, but with some growing pains that can and need to be addressed in order to add to our understanding of the neurobiology of this key region. PMID:22197740

  15. A Developmental Neuroimaging Investigation of the Change Paradigm

    ERIC Educational Resources Information Center

    Thomas, Laura A.; Hall, Julie M.; Skup, Martha; Jenkins, Sarah E.; Pine, Daniel S.; Leibenluft, Ellen

    2011-01-01

    This neuroimaging study examines the development of cognitive flexibility using the Change task in a sample of youths and adults. The Change task requires subjects to inhibit a prepotent response and substitute an alternative response, and the task incorporates an algorithm that adjusts task difficulty in response to subject performance. Data from…

  16. Uncovering the etiology of conversion disorder: insights from functional neuroimaging.

    PubMed

    Ejareh Dar, Maryam; Kanaan, Richard Aa

    2016-01-01

    Conversion disorder (CD) is a syndrome of neurological symptoms arising without organic cause, arguably in response to emotional stress, but the exact neural substrates of these symptoms and the underlying mechanisms remain poorly understood with the hunt for a biological basis afoot for centuries. In the past 15 years, novel insights have been gained with the advent of functional neuroimaging studies in patients suffering from CDs in both motor and nonmotor domains. This review summarizes recent functional neuroimaging studies including functional magnetic resonance imaging (fMRI), single photon emission computerized tomography (SPECT), and positron emission tomography (PET) to see whether they bring us closer to understanding the etiology of CD. Convergent functional neuroimaging findings suggest alterations in brain circuits that could point to different mechanisms for manifesting functional neurological symptoms, in contrast with feigning or healthy controls. Abnormalities in emotion processing and in emotion-motor processing suggest a diathesis, while differential reactions to certain stressors implicate a specific response to trauma. No comprehensive theory emerges from these clues, and all results remain preliminary, but functional neuroimaging has at least given grounds for hope that a model for CD may soon be found. PMID:26834476

  17. Neuroimaging characteristics of patients with focal hand dystonia.

    PubMed

    Hinkley, Leighton B N; Webster, Rebecca L; Byl, Nancy N; Nagarajan, Srikantan S

    2009-01-01

    NARRATIVE REVIEW: Advances in structural and functional imaging have provided both scientists and clinicians with information about the neural mechanisms underlying focal hand dystonia (FHd), a motor disorder associated with aberrant posturing and patterns of muscle contraction specific to movements of the hand. Consistent with the hypothesis that FHd is the result of reorganization in cortical fields, studies in neuroimaging have confirmed alterations in the topography and response properties of somatosensory and motor areas of the brain. Noninvasive stimulation of these regions also demonstrates that FHd may be due to reductions in inhibition between competing sensory and motor representations. Compromises in neuroanatomical structure, such as white matter density and gray matter volume, have also been identified through neuroimaging methods. These advances in neuroimaging have provided clinicians with an expanded understanding of the changes in the brain that contribute to FHd. These findings should provide a foundation for the development of retraining paradigms focused on reversing overlapping sensory representations and interactions between brain regions in patients with FHd. Continued collaborations between health professionals who treat FHd and research scientists who examine the brain using neuroimaging tools are imperative for answering difficult questions about patients with specific movement disorders. PMID:19217255

  18. 25 years of neuroimaging in amyotrophic lateral sclerosis

    PubMed Central

    Foerster, Bradley R.; Welsh, Robert C.; Feldman, Eva L.

    2014-01-01

    Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease for which a precise cause has not yet been identified. Standard CT or MRI evaluation does not demonstrate gross structural nervous system changes in ALS, so conventional neuroimaging techniques have provided little insight into the pathophysiology of this disease. Advanced neuroimaging techniques—such as structural MRI, diffusion tensor imaging and proton magnetic resonance spectroscopy—allow evaluation of alterations of the nervous system in ALS. These alterations include focal loss of grey and white matter and reductions in white matter tract integrity, as well as changes in neural networks and in the chemistry, metabolism and receptor distribution in the brain. Given their potential for investigation of both brain structure and function, advanced neuroimaging methods offer important opportunities to improve diagnosis, guide prognosis, and direct future treatment strategies in ALS. In this article, we review the contributions made by various advanced neuroimaging techniques to our understanding of the impact of ALS on different brain regions, and the potential role of such measures in biomarker development. PMID:23917850

  19. Functional neuroimaging of emotional learning and autonomic reactions.

    PubMed

    Peper, Martin; Herpers, Martin; Spreer, Joachim; Hennig, Jürgen; Zentner, Josef

    2006-06-01

    This article provides a selective overview of the functional neuroimaging literature with an emphasis on emotional activation processes. Emotions are fast and flexible response systems that provide basic tendencies for adaptive action. From the range of involved component functions, we first discuss selected automatic mechanisms that control basic adaptational changes. Second, we illustrate how neuroimaging work has contributed to the mapping of the network components associated with basic emotion families (fear, anger, disgust, happiness), and secondary dimensional concepts that organise the meaning space for subjective experience and verbal labels (emotional valence, activity/intensity, approach/withdrawal, etc.). Third, results and methodological difficulties are discussed in view of own neuroimaging experiments that investigated the component functions involved in emotional learning. The amygdala, prefrontal cortex, and striatum form a network of reciprocal connections that show topographically distinct patterns of activity as a correlate of up and down regulation processes during an emotional episode. Emotional modulations of other brain systems have attracted recent research interests. Emotional neuroimaging calls for more representative designs that highlight the modulatory influences of regulation strategies and socio-cultural factors responsible for inhibitory control and extinction. We conclude by emphasising the relevance of the temporal process dynamics of emotional activations that may provide improved prediction of individual differences in emotionality. PMID:16750614

  20. A review of β-amyloid neuroimaging in Alzheimer's disease

    PubMed Central

    Adlard, Paul A.; Tran, Bob A.; Finkelstein, David I.; Desmond, Patricia M.; Johnston, Leigh A.; Bush, Ashley I.; Egan, Gary F.

    2014-01-01

    Alzheimer's disease (AD) is the most common cause of dementia worldwide. As advancing age is the greatest risk factor for developing AD, the number of those afflicted is expected to increase markedly with the aging of the world's population. The inability to definitively diagnose AD until autopsy remains an impediment to establishing effective targeted treatments. Neuroimaging has enabled in vivo visualization of pathological changes in the brain associated with the disease, providing a greater understanding of its pathophysiological development and progression. However, neuroimaging biomarkers do not yet offer clear advantages over current clinical diagnostic criteria for them to be accepted into routine clinical use. Nonetheless, current insights from neuroimaging combined with the elucidation of biochemical and molecular processes in AD are informing the ongoing development of new imaging techniques and their application. Much of this research has been greatly assisted by the availability of transgenic mouse models of AD. In this review we summarize the main efforts of neuroimaging in AD in humans and in mouse models, with a specific focus on β-amyloid, and discuss the potential of new applications and novel approaches. PMID:25400539

  1. Neuroimaging findings in late-onset schizophrenia and bipolar disorder.

    PubMed

    Hahn, Changtae; Lim, Hyun Kook; Lee, Chang Uk

    2014-03-01

    In recent years, there has been an increasing interest in late-onset mental disorders. Among them, geriatric schizophrenia and bipolar disorder are significant health care risks and major causes of disability. We discussed whether late-onset schizophrenia (LOS) and late-onset bipolar (LOB) disorder can be a separate entity from early-onset schizophrenia (EOS) and early-onset bipolar (EOB) disorder in a subset of late-life schizophrenia or late-life bipolar disorder through neuroimaging studies. A literature search for imaging studies of LOS or LOB was performed in the PubMed database. Search terms used were "(imaging OR MRI OR CT OR SPECT OR DTI OR PET OR fMRI) AND (schizophrenia or bipolar disorder) AND late onset." Articles that were published in English before October 2013 were included. There were a few neuroimaging studies assessing whether LOS and LOB had different disease-specific neural substrates compared with EOS and EOB. These researches mainly observed volumetric differences in specific brain regions, white matter hyperintensities, diffusion tensor imaging, or functional neuroimaging to explore the differences between LOS and LOB and EOS and EOB. The aim of this review was to highlight the neural substrates involved in LOS and LOB through neuroimaging studies. The exploration of neuroanatomical markers may be the key to the understanding of underlying neurobiology in LOS and LOB. PMID:24401535

  2. Neuroimaging of the periaqueductal gray: state of the field.

    PubMed

    Linnman, Clas; Moulton, Eric A; Barmettler, Gabi; Becerra, Lino; Borsook, David

    2012-03-01

    This review and meta-analysis aims at summarizing and integrating the human neuroimaging studies that report periaqueductal gray (PAG) involvement; 250 original manuscripts on human neuroimaging of the PAG were identified. A narrative review and meta-analysis using activation likelihood estimates is included. Behaviors covered include pain and pain modulation, anxiety, bladder and bowel function and autonomic regulation. Methods include structural and functional magnetic resonance imaging, functional connectivity measures, diffusion weighted imaging and positron emission tomography. Human neuroimaging studies in healthy and clinical populations largely confirm the animal literature indicating that the PAG is involved in homeostatic regulation of salient functions such as pain, anxiety and autonomic function. Methodological concerns in the current literature, including resolution constraints, imaging artifacts and imprecise neuroanatomical labeling are discussed, and future directions are proposed. A general conclusion is that PAG neuroimaging is a field with enormous potential to translate animal data onto human behaviors, but with some growing pains that can and need to be addressed in order to add to our understanding of the neurobiology of this key region. PMID:22197740

  3. Auditory-limbic interactions in chronic tinnitus: Challenges for neuroimaging research.

    PubMed

    Leaver, Amber M; Seydell-Greenwald, Anna; Rauschecker, Josef P

    2016-04-01

    Tinnitus is a widespread auditory disorder affecting approximately 10-15% of the population, often with debilitating consequences. Although tinnitus commonly begins with damage to the auditory system due to loud-noise exposure, aging, or other etiologies, the exact neurophysiological basis of chronic tinnitus remains unknown. Many researchers point to a central auditory origin of tinnitus; however, a growing body of evidence also implicates other brain regions, including the limbic system. Correspondingly, we and others have proposed models of tinnitus in which the limbic and auditory systems both play critical roles and interact with one another. Specifically, we argue that damage to the auditory system generates an initial tinnitus signal, consistent with previous research. In our model, this "transient" tinnitus is suppressed when a limbic frontostriatal network, comprised of ventromedial prefrontal cortex and ventral striatum, successfully modulates thalamocortical transmission in the auditory system. Thus, in chronic tinnitus, limbic-system damage and resulting inefficiency of auditory-limbic interactions prevents proper compensation of the tinnitus signal. Neuroimaging studies utilizing connectivity methods like resting-state fMRI and diffusion MRI continue to uncover tinnitus-related anomalies throughout auditory, limbic, and other brain systems. However, directly assessing interactions between these brain regions and networks has proved to be more challenging. Here, we review existing empirical support for models of tinnitus stressing a critical role for involvement of "non-auditory" structures in tinnitus pathophysiology, and discuss the possible impact of newly refined connectivity techniques from neuroimaging on tinnitus research. PMID:26299843

  4. Are You Being Rejected or Excluded? Insights from Neuroimaging Studies Using Different Rejection Paradigms

    PubMed Central

    2012-01-01

    Rejection sensitivity is the heightened tendency to perceive or anxiously expect disengagement from others during social interaction. There has been a recent wave of neuroimaging studies of rejection. The aim of the current review was to determine key brain regions involved in social rejection by selectively reviewing neuroimaging studies that employed one of three paradigms of social rejection, namely social exclusion during a ball-tossing game, evaluating feedback about preference from peers and viewing scenes depicting rejection during social interaction. Across the different paradigms of social rejection, there was concordance in regions for experiencing rejection, namely dorsal anterior cingulate cortex (ACC), subgenual ACC and ventral ACC. Functional dissociation between the regions for experiencing rejection and those for emotion regulation, namely medial prefrontal cortex, ventrolateral prefrontal cortex (VLPFC) and ventral striatum, was evident in the positive association between social distress and regions for experiencing rejection and the inverse association between social distress and the emotion regulation regions. The paradigms of social exclusion and scenes depicting rejection in social interaction were more adept at evoking rejection-specific neural responses. These responses were varyingly influenced by the amount of social distress during the task, social support received, self-esteem and social competence. Presenting rejection cues as scenes of people in social interaction showed high rejection sensitive or schizotypal individuals to under-activate the dorsal ACC and VLPFC, suggesting that such individuals who perceive rejection cues in others down-regulate their response to the perceived rejection by distancing themselves from the scene. PMID:23430682

  5. Neurocognitive-genetic and neuroimaging-genetic research paradigms in schizophrenia and bipolar disorder.

    PubMed

    Kurnianingsih, Yoanna Arlina; Kuswanto, Carissa Nadia; McIntyre, Roger S; Qiu, Anqi; Ho, Beng Choon; Sim, Kang

    2011-11-01

    Studies examining intermediate phenotypes such as neurocognitive and neuroanatomical measures along with susceptibility genes are important for improving our understanding of the neural basis of schizophrenia (SZ) and bipolar disorder (BD). In this paper, we review extant studies involving neurocognitive-genetic and neuroimaging-genetic perspectives and particularly related to catechol-O-methyltransferase (COMT), brain-derived neurotrophic factor (BDNF) and neuregulin-1 (NRG1) genes in SZ and BD. In terms of neurocognitive-genetic investigations, COMT and BDNF are the two most studied candidate genes especially in patients with SZ. Whereas BDNF Met carriers perform worse on verbal working memory, problem solving and visuo-spatial abilities, COMT Met carriers perform better in working memory, attention, executive functioning with evidence of genotype by diagnosis interactions including high-risk individuals. In terms of genetic-structural MRI studies, patients with SZ are found to have reductions in the frontal, temporal, parietal cortices, and limbic regions, which are associated with BDNF, COMT, and NRGI genes. Genetic-functional MRI studies in psychotic disorders are sparse, especially with regard to BD. These neurocognitive and neuroimaging findings are associated with genes which are implicated in functional pathways related to neuronal signaling, inter-neuronal communication and neuroplasticity. PMID:21688113

  6. Dissociable Genetic Contributions to Error Processing: A Multimodal Neuroimaging Study

    PubMed Central

    Agam, Yigal; Vangel, Mark; Roffman, Joshua L.; Gallagher, Patience J.; Chaponis, Jonathan; Haddad, Stephen; Goff, Donald C.; Greenberg, Jennifer L.; Wilhelm, Sabine; Smoller, Jordan W.; Manoach, Dara S.

    2014-01-01

    Background Neuroimaging studies reliably identify two markers of error commission: the error-related negativity (ERN), an event-related potential, and functional MRI activation of the dorsal anterior cingulate cortex (dACC). While theorized to reflect the same neural process, recent evidence suggests that the ERN arises from the posterior cingulate cortex not the dACC. Here, we tested the hypothesis that these two error markers also have different genetic mediation. Methods We measured both error markers in a sample of 92 comprised of healthy individuals and those with diagnoses of schizophrenia, obsessive-compulsive disorder or autism spectrum disorder. Participants performed the same task during functional MRI and simultaneously acquired magnetoencephalography and electroencephalography. We examined the mediation of the error markers by two single nucleotide polymorphisms: dopamine D4 receptor (DRD4) C-521T (rs1800955), which has been associated with the ERN and methylenetetrahydrofolate reductase (MTHFR) C677T (rs1801133), which has been associated with error-related dACC activation. We then compared the effects of each polymorphism on the two error markers modeled as a bivariate response. Results We replicated our previous report of a posterior cingulate source of the ERN in healthy participants in the schizophrenia and obsessive-compulsive disorder groups. The effect of genotype on error markers did not differ significantly by diagnostic group. DRD4 C-521T allele load had a significant linear effect on ERN amplitude, but not on dACC activation, and this difference was significant. MTHFR C677T allele load had a significant linear effect on dACC activation but not ERN amplitude, but the difference in effects on the two error markers was not significant. Conclusions DRD4 C-521T, but not MTHFR C677T, had a significant differential effect on two canonical error markers. Together with the anatomical dissociation between the ERN and error-related dACC activation

  7. Experimental evidence that a high electric field acts as an efficient external parameter during crystalline growth of bulk oxide

    NASA Astrophysics Data System (ADS)

    Hicher, P.; Haumont, R.; Saint-Martin, R.; Mininger, X.; Berthet, P.; Revcolevschi, A.

    2015-01-01

    A new crystal growth device, in which a high static external electric voltage (up to 14 kV) is added to a floating zone method, is described. Our first experiments show that the application of such an electric field acts like an external force, introducing a pressure effect which is in direct competition with temperature in the solid/liquid thermodynamic equilibrium. High electric fields could therefore be an additional parameter in crystal growth, opening original routes to the synthesis of new materials.

  8. Experimental evidence of electric inhibition in fast electron penetration and of electric-field-limited fast electron transport in dense matter

    PubMed

    Pisani; Bernardinello; Batani; Antonicci; Martinolli; Koenig; Gremillet; Amiranoff; Baton; Davies; Hall; Scott; Norreys; Djaoui; Rousseaux; Fews; Bandulet; Pepin

    2000-11-01

    Fast electron generation and propagation were studied in the interaction of a green laser with solids. The experiment, carried out with the LULI TW laser (350 fs, 15 J), used K(alpha) emission from buried fluorescent layers to measure electron transport. Results for conductors (Al) and insulators (plastic) are compared with simulations: in plastic, inhibition in the propagation of fast electrons is observed, due to electric fields which become the dominant factor in electron transport. PMID:11102017

  9. Neuroimaging schizophrenia: a picture is worth a thousand words, but is it saying anything important?

    PubMed

    Ahmed, Anthony O; Buckley, Peter F; Hanna, Mona

    2013-03-01

    Schizophrenia is characterized by neurostructural and neurofunctional aberrations that have now been demonstrated through neuroimaging research. The article reviews recent studies that have attempted to use neuroimaging to understand the relation between neurological abnormalities and aspects of the phenomenology of schizophrenia. Neuroimaging studies show that neurostructural and neurofunctional abnormalities are present in people with schizophrenia and their close relatives and may represent putative endophenotypes. Neuroimaging phenotypes predict the emergence of psychosis in individuals classified as high-risk. Neuroimaging studies have linked structural and functional abnormalities to symptoms; and progressive structural changes to clinical course and functional outcome. Neuroimaging has successfully indexed the neurotoxic and neuroprotective effects of schizophrenia treatments. Pictures can inform about aspects of the phenomenology of schizophrenia including etiology, onset, symptoms, clinical course, and treatment effects but this assertion is tempered by the scientific and practical limitations of neuroimaging. PMID:23397252

  10. The neural network for tool-related cognition: An activation likelihood estimation meta-analysis of 70 neuroimaging contrasts

    PubMed Central

    Ishibashi, Ryo; Pobric, Gorana; Saito, Satoru; Lambon Ralph, Matthew A.

    2016-01-01

    ABSTRACT The ability to recognize and use a variety of tools is an intriguing human cognitive function. Multiple neuroimaging studies have investigated neural activations with various types of tool-related tasks. In the present paper, we reviewed tool-related neural activations reported in 70 contrasts from 56 neuroimaging studies and performed a series of activation likelihood estimation (ALE) meta-analyses to identify tool-related cortical circuits dedicated either to general tool knowledge or to task-specific processes. The results indicate the following: (a) Common, task-general processing regions for tools are located in the left inferior parietal lobule (IPL) and ventral premotor cortex; and (b) task-specific regions are located in superior parietal lobule (SPL) and dorsal premotor area for imagining/executing actions with tools and in bilateral occipito-temporal cortex for recognizing/naming tools. The roles of these regions in task-general and task-specific activities are discussed with reference to evidence from neuropsychology, experimental psychology and other neuroimaging studies. PMID:27362967

  11. Physiological and modeling evidence for focal transcranial electrical brain stimulation in humans: A basis for high-definition tDCS

    PubMed Central

    Edwards, Dylan; Cortes, Mar; Datta, Abhishek; Minhas, Preet; Wassermann, Eric M.; Bikson, Marom

    2015-01-01

    Transcranial Direct Current Stimulation (tDCS) is a non-invasive, low-cost, well-tolerated technique producing lasting modulation of cortical excitability. Behavioral and therapeutic outcomes of tDCS are linked to the targeted brain regions, but there is little evidence that current reaches the brain as intended. We aimed to: (1) validate a computational model for estimating cortical electric fields in human transcranial stimulation, and (2) assess the magnitude and spread of cortical electric field with a novel High-Definition tDCS (HD-tDCS) scalp montage using a 4×1-Ring electrode configuration. In three healthy adults, Transcranial Electrical Stimulation (TES) over primary motor cortex (M1) was delivered using the 4×1 montage (4× cathode, surrounding a single central anode; montage radius ~3 cm) with sufficient intensity to elicit a discrete muscle twitch in the hand. The estimated current distribution in M1 was calculated using the individualized MRI-based model, and compared with the observed motor response across subjects. The response magnitude was quantified with stimulation over motor cortex as well as anterior and posterior to motor cortex. In each case the model data were consistent with the motor response across subjects. The estimated cortical electric fields with the 4×1 montage were compared (area, magnitude, direction) for TES and tDCS in each subject. We provide direct evidence in humans that TES with a 4×1-Ring configuration can activate motor cortex and that current does not substantially spread outside the stimulation area. Computational models predict that both TES and tDCS waveforms using the 4×1-Ring configuration generate electric fields in cortex with comparable gross current distribution, and preferentially directed normal (inward) currents. The agreement of modeling and experimental data for both current delivery and focality support the use of the HD-tDCS 4×1-Ring montage for cortically targeted neuromodulation. PMID:23370061

  12. Volumetric neuroimage analysis extensions for the MIPAV software package.

    PubMed

    Bazin, Pierre-Louis; Cuzzocreo, Jennifer L; Yassa, Michael A; Gandler, William; McAuliffe, Matthew J; Bassett, Susan S; Pham, Dzung L

    2007-09-15

    We describe a new collection of publicly available software tools for performing quantitative neuroimage analysis. The tools perform semi-automatic brain extraction, tissue classification, Talairach alignment, and atlas-based measurements within a user-friendly graphical environment. They are implemented as plug-ins for MIPAV, a freely available medical image processing software package from the National Institutes of Health. Because the plug-ins and MIPAV are implemented in Java, both can be utilized on nearly any operating system platform. In addition to the software plug-ins, we have also released a digital version of the Talairach atlas that can be used to perform regional volumetric analyses. Several studies are conducted applying the new tools to simulated and real neuroimaging data sets. PMID:17604116

  13. Neuroimaging the Effectiveness of Substance Use Disorder Treatments.

    PubMed

    Cabrera, Elizabeth A; Wiers, Corinde E; Lindgren, Elsa; Miller, Gregg; Volkow, Nora D; Wang, Gene-Jack

    2016-09-01

    Neuroimaging techniques to measure the function and biochemistry of the human brain such as positron emission tomography (PET), proton magnetic resonance spectroscopy ((1)H MRS), and functional magnetic resonance imaging (fMRI), are powerful tools for assessing neurobiological mechanisms underlying the response to treatments in substance use disorders. Here, we review the neuroimaging literature on pharmacological and behavioral treatment in substance use disorder. We focus on neural effects of medications that reduce craving (e.g., naltrexone, bupropion hydrochloride, baclofen, methadone, varenicline) and that improve cognitive control (e.g., modafinil, N-acetylcysteine), of behavioral treatments for substance use disorders (e.g., cognitive bias modification training, virtual reality, motivational interventions) and neuromodulatory interventions such as neurofeedback and transcranial magnetic stimulation. A consistent finding for the effectiveness of therapeutic interventions identifies the improvement of executive control networks and the dampening of limbic activation, highlighting their values as targets for therapeutic interventions in substance use disorders. PMID:27184387

  14. Publication trends in neuroimaging of minimally conscious states.

    PubMed

    Garnett, Alex; Lee, Grace; Illes, Judy

    2013-01-01

    We used existing and customized bibliometric and scientometric methods to analyze publication trends in neuroimaging research of minimally conscious states and describe the domain in terms of its geographic, contributor, and content features. We considered publication rates for the years 2002-2011, author interconnections, the rate at which new authors are added, and the domains that inform the work of author contributors. We also provided a content analysis of clinical and ethical themes within the relevant literature. We found a 27% growth in the number of papers over the period of study, professional diversity among a wide range of peripheral author contributors but only few authors who dominate the field, and few new technical paradigms and clinical themes that would fundamentally expand the landscape. The results inform both the science of consciousness as well as parallel ethics and policy studies of the potential for translational challenges of neuroimaging in research and health care of people with disordered states of consciousness. PMID:24109545

  15. CATI: A Large Distributed Infrastructure for the Neuroimaging of Cohorts.

    PubMed

    Operto, Grégory; Chupin, Marie; Batrancourt, Bénédicte; Habert, Marie-Odile; Colliot, Olivier; Benali, Habib; Poupon, Cyril; Champseix, Catherine; Delmaire, Christine; Marie, Sullivan; Rivière, Denis; Pélégrini-Issac, Mélanie; Perlbarg, Vincent; Trebossen, Régine; Bottlaender, Michel; Frouin, Vincent; Grigis, Antoine; Orfanos, Dimitri Papadopoulos; Dary, Hugo; Fillon, Ludovic; Azouani, Chabha; Bouyahia, Ali; Fischer, Clara; Edward, Lydie; Bouin, Mathilde; Thoprakarn, Urielle; Li, Jinpeng; Makkaoui, Leila; Poret, Sylvain; Dufouil, Carole; Bouteloup, Vincent; Chételat, Gaël; Dubois, Bruno; Lehéricy, Stéphane; Mangin, Jean-François; Cointepas, Yann

    2016-07-01

    This paper provides an overview of CATI, a platform dedicated to multicenter neuroimaging. Initiated by the French Alzheimer's plan (2008-2012), CATI is a research project called on to provide service to other projects like an industrial partner. Its core mission is to support the neuroimaging of large populations, providing concrete solutions to the increasing complexity involved in such projects by bringing together a service infrastructure, the know-how of its expert academic teams and a large-scale, harmonized network of imaging facilities. CATI aims to make data sharing across studies easier and promotes sharing as much as possible. In the last 4 years, CATI has assisted the clinical community by taking charge of 35 projects so far and has emerged as a recognized actor at the national and international levels. PMID:27066973

  16. Structural Neuroimaging Findings in Mild Traumatic Brain Injury.

    PubMed

    Bigler, Erin D; Abildskov, Tracy J; Goodrich-Hunsaker, Naomi J; Black, Garrett; Christensen, Zachary P; Huff, Trevor; Wood, Dawn-Marie G; Hesselink, John R; Wilde, Elisabeth A; Max, Jeffrey E

    2016-09-01

    Common neuroimaging findings in mild traumatic brain injury (mTBI), including sport-related concussion (SRC), are reviewed based on computed tomography and magnetic resonance imaging (MRI). Common abnormalities radiologically identified on the day of injury, typically a computed tomographic scan, are in the form of contusions, small subarachnoid or intraparenchymal hemorrhages as well as subdural and epidural collections, edema, and skull fractures. Common follow-up neuroimaging findings with MRI include white matter hyperintensities, hypointense signal abnormalities that reflect prior hemorrhage, focal encephalomalacia, presence of atrophy and/or dilated Virchow-Robins perivascular space. The MRI findings from a large pediatric mTBI study show low frequency of positive MRI findings at 6 months postinjury. The review concludes with an examination of some of the advanced MRI-based image analysis methods that can be performed in the patient who has sustained an mTBI. PMID:27482782

  17. Pain perception and hypnosis: findings from recent functional neuroimaging studies.

    PubMed

    Del Casale, Antonio; Ferracuti, Stefano; Rapinesi, Chiara; Serata, Daniele; Caltagirone, Saverio Simone; Savoja, Valeria; Piacentino, Daria; Callovini, Gemma; Manfredi, Giovanni; Sani, Gabriele; Kotzalidis, Georgios D; Girardi, Paolo

    2015-01-01

    Hypnosis modulates pain perception and tolerance by affecting cortical and subcortical activity in brain regions involved in these processes. By reviewing functional neuroimaging studies focusing on pain perception under hypnosis, the authors aimed to identify brain activation-deactivation patterns occurring in hypnosis-modulated pain conditions. Different changes in brain functionality occurred throughout all components of the pain network and other brain areas. The anterior cingulate cortex appears to be central in modulating pain circuitry activity under hypnosis. Most studies also showed that the neural functions of the prefrontal, insular, and somatosensory cortices are consistently modified during hypnosis-modulated pain conditions. Functional neuroimaging studies support the clinical use of hypnosis in the management of pain conditions. PMID:25719519

  18. SchizConnect: Virtual Data Integration in Neuroimaging

    PubMed Central

    Ambite, Jose Luis; Tallis, Marcelo; Alpert, Kathryn; Keator, David B.; King, Margaret; Landis, Drew; Konstantinidis, George; Calhoun, Vince D.; Potkin, Steven G.; Turner, Jessica A.; Wang, Lei

    2015-01-01

    In many scientific domains, including neuroimaging studies, there is a need to obtain increasingly larger cohorts to achieve the desired statistical power for discovery. However, the economics of imaging studies make it unlikely that any single study or consortia can achieve the desired sample sizes. What is needed is an architecture that can easily incorporate additional studies as they become available. We present such architecture based on a virtual data integration approach, where data remains at the original sources, and is retrieved and harmonized in response to user queries. This is in contrast to approaches that move the data to a central warehouse. We implemented our approach in the SchizConnect system that integrates data from three neuroimaging consortia on Schizophrenia: FBIRN's Human Imaging Database (HID), MRN's Collaborative Imaging and Neuroinformatics System (COINS), and the NUSDAST project at XNAT Central. A portal providing harmonized access to these sources is publicly deployed at schizconnect.org. PMID:26688837

  19. Genetic imaging consortium for addiction medicine: From neuroimaging to genes.

    PubMed

    Mackey, Scott; Kan, Kees-Jan; Chaarani, Bader; Alia-Klein, Nelly; Batalla, Albert; Brooks, Samantha; Cousijn, Janna; Dagher, Alain; de Ruiter, Michiel; Desrivieres, Sylvane; Feldstein Ewing, Sarah W; Goldstein, Rita Z; Goudriaan, Anna E; Heitzeg, Mary M; Hutchison, Kent; Li, Chiang-Shan R; London, Edythe D; Lorenzetti, Valentina; Luijten, Maartje; Martin-Santos, Rocio; Morales, Angelica M; Paulus, Martin P; Paus, Tomas; Pearlson, Godfrey; Schluter, Renée; Momenan, Reza; Schmaal, Lianne; Schumann, Gunter; Sinha, Rajita; Sjoerds, Zsuzsika; Stein, Dan J; Stein, Elliot A; Solowij, Nadia; Tapert, Susan; Uhlmann, Anne; Veltman, Dick; van Holst, Ruth; Walter, Henrik; Wright, Margaret J; Yucel, Murat; Yurgelun-Todd, Deborah; Hibar, Derrek P; Jahanshad, Neda; Thompson, Paul M; Glahn, David C; Garavan, Hugh; Conrod, Patricia

    2016-01-01

    Since the sample size of a typical neuroimaging study lacks sufficient statistical power to explore unknown genomic associations with brain phenotypes, several international genetic imaging consortia have been organized in recent years to pool data across sites. The challenges and achievements of these consortia are considered here with the goal of leveraging these resources to study addiction. The authors of this review have joined together to form an Addiction working group within the framework of the ENIGMA project, a meta-analytic approach to multisite genetic imaging data. Collectively, the Addiction working group possesses neuroimaging and genomic data obtained from over 10,000 subjects. The deadline for contributing data to the first round of analyses occurred at the beginning of May 2015. The studies performed on this data should significantly impact our understanding of the genetic and neurobiological basis of addiction. PMID:26822360

  20. Neuroimaging in Animal Seizure Models with 18FDG-PET

    PubMed Central

    Mirrione, Martine M.; Tsirka, Stella E.

    2011-01-01

    Small animal neuroimaging has become increasingly available to researchers, expanding the breadth of questions studied with these methods. Applying these noninvasive techniques to the open questions underlying epileptogenesis is no exception. A major advantage of small animal neuroimaging is its translational appeal. Studies can be well controlled and manipulated, examining the living brain in the animal before, during, and after the disease onset or disease treatment. The results can also be compared to data collected on human patients. Over the past decade, we and others have explored metabolic patterns in animal models of epilepsy to gain insight into the circuitry underlying development of the disease. In this paper, we provide technical details on how metabolic imaging that uses 2-deoxy-2[18F]fluoro-D-glucose (18FDG) and positron emission tomography (PET) is performed and explain the strengths and limitations of these studies. We will also highlight recent advances toward understanding epileptogenesis through small animal imaging. PMID:22937232

  1. A practical review of the neuropathology and neuroimaging of multiple sclerosis.

    PubMed

    Matthews, Paul M; Roncaroli, Frederico; Waldman, Adam; Sormani, Maria Pia; De Stefano, Nicola; Giovannoni, Gavin; Reynolds, Richard

    2016-08-01

    The variability in the severity and clinical course of multiple sclerosis (MS) has as its basis an extreme heterogeneity in the location, nature and extent of pathology in the brain and spinal cord. Understanding the underlying neuropathology and associated pathogenetic mechanisms of the disease helps to communicate the rationale for treatment and disease monitoring to patients. Neuroimaging is an important tool for this: it allows clinicians to relate neuropathological changes to clinical presentations and to monitor the course of their disease. Here, we review MS neuropathology and its imaging correlates to provide a practical guide for using MRI to assess disease severity and treatment responses. This provides a foundation for optimal management of patients based on the principle that they show 'no evidence of disease activity'. PMID:27009310

  2. Iconicity in the lab: a review of behavioral, developmental, and neuroimaging research into sound-symbolism

    PubMed Central

    Lockwood, Gwilym; Dingemanse, Mark

    2015-01-01

    This review covers experimental approaches to sound-symbolism—from infants to adults, and from Sapir’s foundational studies to twenty-first century product naming. It synthesizes recent behavioral, developmental, and neuroimaging work into a systematic overview of the cross-modal correspondences that underpin iconic links between form and meaning. It also identifies open questions and opportunities, showing how the future course of experimental iconicity research can benefit from an integrated interdisciplinary perspective. Combining insights from psychology and neuroscience with evidence from natural languages provides us with opportunities for the experimental investigation of the role of sound-symbolism in language learning, language processing, and communication. The review finishes by describing how hypothesis-testing and model-building will help contribute to a cumulative science of sound-symbolism in human language. PMID:26379581

  3. Iconicity in the lab: a review of behavioral, developmental, and neuroimaging research into sound-symbolism.

    PubMed

    Lockwood, Gwilym; Dingemanse, Mark

    2015-01-01

    This review covers experimental approaches to sound-symbolism-from infants to adults, and from Sapir's foundational studies to twenty-first century product naming. It synthesizes recent behavioral, developmental, and neuroimaging work into a systematic overview of the cross-modal correspondences that underpin iconic links between form and meaning. It also identifies open questions and opportunities, showing how the future course of experimental iconicity research can benefit from an integrated interdisciplinary perspective. Combining insights from psychology and neuroscience with evidence from natural languages provides us with opportunities for the experimental investigation of the role of sound-symbolism in language learning, language processing, and communication. The review finishes by describing how hypothesis-testing and model-building will help contribute to a cumulative science of sound-symbolism in human language. PMID:26379581

  4. Animal minds and neuroimaging--bridging the gap between science and ethics?

    PubMed

    Buller, Tom

    2014-04-01

    As Colin Allen has argued, discussions between science and ethics about the mentality and moral status of nonhuman animals often stall on account of the fact that the properties that ethics presents as evidence of animal mentality and moral status, namely consciousness and sentience, are not observable "scientifically respectable" properties. In order to further discussion between science and ethics, it seems, therefore, that we need to identify properties that would satisfy both domains. In this article I examine the mentality and moral status of nonhuman animals from the perspective of neuroethics. By adopting this perspective, we can see how advances in neuroimaging regarding (1) research into the neurobiology of pain, (2) "brain reading," and (3) the minimally conscious state may enable us to identify properties that help bridge the gap between science and ethics, and hence help further the debate about the mentality and moral status of nonhuman animals. PMID:24495745

  5. Cross-View Neuroimage Pattern Analysis in Alzheimer's Disease Staging

    PubMed Central

    Liu, Sidong; Cai, Weidong; Pujol, Sonia; Kikinis, Ron; Feng, Dagan D.

    2016-01-01

    The research on staging of pre-symptomatic and prodromal phase of neurological disorders, e.g., Alzheimer's disease (AD), is essential for prevention of dementia. New strategies for AD staging with a focus on early detection, are demanded to optimize potential efficacy of disease-modifying therapies that can halt or slow the disease progression. Recently, neuroimaging are increasingly used as additional research-based markers to detect AD onset and predict conversion of MCI and normal control (NC) to AD. Researchers have proposed a variety of neuroimaging biomarkers to characterize the patterns of the pathology of AD and MCI, and suggested that multi-view neuroimaging biomarkers could lead to better performance than single-view biomarkers in AD staging. However, it is still unclear what leads to such synergy and how to preserve or maximize. In an attempt to answer these questions, we proposed a cross-view pattern analysis framework for investigating the synergy between different neuroimaging biomarkers. We quantitatively analyzed nine types of biomarkers derived from FDG-PET and T1-MRI, and evaluated their performance in a task of classifying AD, MCI, and NC subjects obtained from the ADNI baseline cohort. The experiment results showed that these biomarkers could depict the pathology of AD from different perspectives, and output distinct patterns that are significantly associated with the disease progression. Most importantly, we found that these features could be separated into clusters, each depicting a particular aspect; and the inter-cluster features could always achieve better performance than the intra-cluster features in AD staging. PMID:26941639

  6. Will neuroimaging ever be used to diagnose pediatric bipolar disorder?

    PubMed

    Chang, Kiki; Adleman, Nancy; Wagner, Christopher; Barnea-Goraly, Naama; Garrett, Amy

    2006-01-01

    There is a great need for discovery of biological markers that could be used diagnostically for pediatric onset disorders, particularly those with potentially confusing phenomenology such as pediatric-onset bipolar disorder (BD). Obtaining these markers would help overcome current subjective diagnostic techniques of relying on parent and child interview and symptomatic history. Brain imaging may be the most logical choice for a diagnostic tool, and certain neurobiological abnormalities have already been found in pediatric BD. However, much work remains to be done before neuroimaging can be used reliably to diagnose this disorder, and because of the nature of BD and the limitations of imaging technology and technique, neuroimaging will likely at most be only a diagnostic aide in the near future. In this paper we discuss the characteristics of pediatric BD that complicate the use of biological markers as diagnostic tools, how neuroimaging techniques have been used to study pediatric BD so far, and the limitations and potential of such techniques for future diagnostic use. PMID:17064431

  7. Pain in multiple sclerosis: A systematic review of neuroimaging studies

    PubMed Central

    Seixas, D.; Foley, P.; Palace, J.; Lima, D.; Ramos, I.; Tracey, I.

    2014-01-01

    Introduction While pain in multiple sclerosis (MS) is common, in many cases the precise mechanisms are unclear. Neuroimaging studies could have a valuable role in investigating the aetiology of pain syndromes. The aim of this review was to synthesise and appraise the current literature on neuroimaging studies of pain syndromes in MS. Methods We systematically searched PubMed and Scopus from their inception dates to the 2nd of April 2013. Studies were selected by predefined inclusion and exclusion criteria. Methodological quality was appraised. Descriptive statistical analysis was conducted. Results We identified 38 studies of variable methodology and quality. All studies but one used conventional structural magnetic resonance imaging, and the majority reported a positive association between location of demyelinating lesions and specific neuropathic pain syndromes. Most investigated headache and facial pain, with more common pain syndromes such as limb pain being relatively understudied. We identified a number of methodological concerns, which along with variable study design and reporting limit our ability to synthesise data. Higher quality studies were however less likely to report positive associations of lesion distribution to pain syndromes. Conclusions Further high quality hypothesis-driven neuroimaging studies of pain syndromes in MS are required to clarify pain mechanisms, particularly for the commonest pain syndromes. PMID:25161898

  8. Abnormal Neuroimaging in a Case of Infant Botulism

    PubMed Central

    Good, Ryan J.; Messacar, Kevin; Stence, Nicholas V.; Press, Craig A.; Carpenter, Todd C.

    2015-01-01

    We present the first case of abnormal neuroimaging in a case of infant botulism. The clinical findings of the patient with constipation, bulbar weakness, and descending, symmetric motor weakness are consistent with the classic findings of infant botulism. Magnetic resonance imaging (MRI), however, revealed restricted diffusion in the brain and enhancement of the cervical nerve roots. Traditionally, normal neuroimaging was used to help differentiate infant botulism from other causes of weakness in infants. Abnormal neuroimaging is seen in other causes of weakness in an infant including metabolic disorders and hypoxic–ischemic injury, but these diagnoses did not fit the clinical findings in this case. The explanation for the MRI abnormalities in the brain and cervical nerve roots is unclear as botulinum toxin acts at presynaptic nerve terminals and does not cross the blood–brain barrier. Possible explanations for the findings include inflammation from the botulinum toxin at the synapse, alterations in sensory signaling and retrograde transport of the botulinum toxin. The patient was treated with human botulism immune globulin and had rapid recovery in weakness. A stool sample from the patient was positive for Type A Clostridium botulinum toxin eventually confirming the diagnosis of infant botulism. The findings in this case support use of human botulism immune globulin when the clinical findings are consistent with infant botulism despite the presence of MRI abnormalities in the brain and cervical nerve roots. PMID:26697417

  9. Pre- and Postnatal Neuroimaging of Congenital Cerebellar Abnormalities.

    PubMed

    Poretti, Andrea; Boltshauser, Eugen; Huisman, Thierry A G M

    2016-02-01

    The human cerebellum has a protracted development that makes it vulnerable to a broad spectrum of developmental disorders including malformations and disruptions. Starting from 19 to 20 weeks of gestation, prenatal magnetic resonance imaging (MRI) can reliably study the developing cerebellum. Pre- and postnatal neuroimaging plays a key role in the diagnostic work-up of congenital cerebellar abnormalities. Diagnostic criteria for cerebellar malformations and disruptions are based mostly on neuroimaging findings. The diagnosis of a Dandy-Walker malformation is based on the presence of hypoplasia, elevation, and counterclockwise upward rotation of the cerebellar vermis and cystic dilatation of the fourth ventricle, which extends posteriorly filling out the posterior fossa. For the diagnosis of Joubert syndrome, the presence of the molar tooth sign (thickened, elongated, and horizontally orientated superior cerebellar peduncles and an abnormally deep interpeduncular fossa) is needed. The diagnostic criteria of rhombencephalosynapsis include a complete or partial absence of the cerebellar vermis and continuity of the cerebellar hemispheres across the midline. Unilateral cerebellar hypoplasia is defined by the complete aplasia or hypoplasia of one cerebellar hemisphere. Familiarity with these diagnostic criteria as well as the broad spectrum of additional neuroimaging findings is important for a correct pre- and postnatal diagnosis. A correct diagnosis is essential for management, prognosis, and counseling of the affected children and their family. PMID:26166429

  10. Robust regression for large-scale neuroimaging studies.

    PubMed

    Fritsch, Virgile; Da Mota, Benoit; Loth, Eva; Varoquaux, Gaël; Banaschewski, Tobias; Barker, Gareth J; Bokde, Arun L W; Brühl, Rüdiger; Butzek, Brigitte; Conrod, Patricia; Flor, Herta; Garavan, Hugh; Lemaitre, Hervé; Mann, Karl; Nees, Frauke; Paus, Tomas; Schad, Daniel J; Schümann, Gunter; Frouin, Vincent; Poline, Jean-Baptiste; Thirion, Bertrand

    2015-05-01

    Multi-subject datasets used in neuroimaging group studies have a complex structure, as they exhibit non-stationary statistical properties across regions and display various artifacts. While studies with small sample sizes can rarely be shown to deviate from standard hypotheses (such as the normality of the residuals) due to the poor sensitivity of normality tests with low degrees of freedom, large-scale studies (e.g. >100 subjects) exhibit more obvious deviations from these hypotheses and call for more refined models for statistical inference. Here, we demonstrate the benefits of robust regression as a tool for analyzing large neuroimaging cohorts. First, we use an analytic test based on robust parameter estimates; based on simulations, this procedure is shown to provide an accurate statistical control without resorting to permutations. Second, we show that robust regression yields more detections than standard algorithms using as an example an imaging genetics study with 392 subjects. Third, we show that robust regression can avoid false positives in a large-scale analysis of brain-behavior relationships with over 1500 subjects. Finally we embed robust regression in the Randomized Parcellation Based Inference (RPBI) method and demonstrate that this combination further improves the sensitivity of tests carried out across the whole brain. Altogether, our results show that robust procedures provide important advantages in large-scale neuroimaging group studies. PMID:25731989

  11. The neuroimaging research process from the participants' perspective.

    PubMed

    Cooke, Richard; Peel, Elizabeth; Shaw, Rachel L; Senior, Carl

    2007-02-01

    The aim of this study was to investigate participants' experiences of taking part in research conducted using fMRI or MEG procedures. Forty-four participants completed a questionnaire after taking part in either fMRI or MEG experiments; the questionnaire asked about experiences of and attitudes toward fMRI/MEG. Ten follow-up interviews were conducted to enable an in-depth analysis of these attitudes and experiences. The findings were generally positive: all participants thought fMRI and MEG were safe procedures, 93% would recommend participating in neuroimaging research to their friends and family, and participants were positive about participating in future neuroimaging research. However, some negative issues were identified. Some participants reported feeling nervous prior to scanning procedures, several participants reported side-effects after taking part, a number of participants were upset at being in a confined space and some participants did not feel confident about exiting the scanner in an emergency. Several recommendations for researchers are made, including a virtual tour of the scanning equipment during the consenting process in order to better prepare potential participants for the scanning experience and to minimize the potential psychological discomfort sometimes experienced in neuroimaging research. PMID:16806548

  12. Neuroimaging correlates of aggression in schizophrenia: an update

    PubMed Central

    Hoptman, Matthew J.; Antonius, Daniel

    2015-01-01

    Purpose of review Aggression in schizophrenia is associated with poor treatment outcomes, hospital admissions, and stigmatization of patients. As such it represents an important public health issue. This article reviews recent neuroimaging studies of aggression in schizophrenia, focusing on PET/single photon emission computed tomography and MRI methods. Recent findings The neuroimaging literature on aggression in schizophrenia is in a period of development. This is attributable in part to the heterogeneous nature and basis of that aggression. Radiological methods have consistently shown reduced activity in frontal and temporal regions. MRI brain volumetric studies have been less consistent, with some studies finding increased volumes of inferior frontal structures, and others finding reduced volumes in aggressive individuals with schizophrenia. Functional MRI studies have also had inconsistent results, with most finding reduced activity in inferior frontal and temporal regions, but some also finding increased activity in other regions. Some studies have made a distinction between types of aggression in schizophrenia in the context of antisocial traits, and this appears to be useful in understanding the neuroimaging literature. Summary Frontal and temporal abnormalities appear to be a consistent feature of aggression in schizophrenia, but their precise nature likely differs because of the heterogeneous nature of that behavior. PMID:21178624

  13. Neuroimaging Insights into the Pathophysiology of Sleep Disorders

    PubMed Central

    Desseilles, Martin; Dang-Vu, Thanh; Schabus, Manuel; Sterpenich, Virginie; Maquet, Pierre; Schwartz, Sophie

    2008-01-01

    Neuroimaging methods can be used to investigate whether sleep disorders are associated with specific changes in brain structure or regional activity. However, it is still unclear how these new data might improve our understanding of the pathophysiology underlying adult sleep disorders. Here we review functional brain imaging findings in major intrinsic sleep disorders (i.e., idiopathic insomnia, narcolepsy, and obstructive sleep apnea) and in abnormal motor behavior during sleep (i.e., periodic limb movement disorder and REM sleep behavior disorder). The studies reviewed include neuroanatomical assessments (voxel-based morphometry, magnetic resonance spectroscopy), metabolic/functional investigations (positron emission tomography, single photon emission computed tomography, functional magnetic resonance imaging), and ligand marker measurements. Based on the current state of the research, we suggest that brain imaging is a useful approach to assess the structural and functional correlates of sleep impairments as well as better understand the cerebral consequences of various therapeutic approaches. Modern neuroimaging techniques therefore provide a valuable tool to gain insight into possible pathophysiological mechanisms of sleep disorders in adult humans. Citation: Desseilles M; Dang-Vu TD; Schabus M; Sterpenich V; Maquet P; Schwartz S. Neuroimaging insights into the pathophysiology of sleep disorders. SLEEP 2008;31(6):777–794. PMID:18548822

  14. Neuroimaging of Children Following Prenatal Drug Exposure

    PubMed Central

    Derauf, Chris; Kekatpure, Minal; Neyzi, Nurunisa; Lester, Barry; Kosofsky, Barry

    2009-01-01

    Recent advances in MR-based brain imaging methods have provided unprecedented capabilities to visualize the brain. Application of these methods has allowed identification of brain structures and patterns of functional activation altered in offspring of mothers who used licit (e.g., alcohol and tobacco) and illicit (e.g., cocaine, methamphetamine, and marijuana) drugs during pregnancy. Here we review that literature, which though somewhat limited by the complexities of separating the specific effects of each drug from other confounding variables, points to sets of interconnected brain structures as being altered following prenatal exposure to drugs of abuse. In particular, dopamine-rich cortical (e.g., frontal cortex) and subcortical (e.g., basal ganglia) fetal brain structures show evidence of vulnerability to intrauterine drug exposure suggesting that during brain development drugs of abuse share a specific profile of developmental neurotoxicity. Such brain malformations may shed light on mechanisms underlying prenatal drug-induced brain injury, may serve as bio-markers of significant intrauterine drug exposure, and may additionally be predictors of subsequent neuro-developmental compromise. Wider clinical use of these research-based non-invasive methods will allow for improved diagnosis and allocation of therapeutic resources for affected infants, children, and young adults. PMID:19560049

  15. Neuroimaging and neuromodulation approaches to study eating behavior and prevent and treat eating disorders and obesity.

    PubMed

    Val-Laillet, D; Aarts, E; Weber, B; Ferrari, M; Quaresima, V; Stoeckel, L E; Alonso-Alonso, M; Audette, M; Malbert, C H; Stice, E

    2015-01-01

    Functional, molecular and genetic neuroimaging has highlighted the existence of brain anomalies and neural vulnerability factors related to obesity and eating disorders such as binge eating or anorexia nervosa. In particular, decreased basal metabolism in the prefrontal cortex and striatum as well as dopaminergic alterations have been described in obese subjects, in parallel with increased activation of reward brain areas in response to palatable food cues. Elevated reward region responsivity may trigger food craving and predict future weight gain. This opens the way to prevention studies using functional and molecular neuroimaging to perform early diagnostics and to phenotype subjects at risk by exploring different neurobehavioral dimensions of the food choices and motivation processes. In the first part of this review, advantages and limitations of neuroimaging techniques, such as functional magnetic resonance imaging (fMRI), positron emission tomography (PET), single photon emission computed tomography (SPECT), pharmacogenetic fMRI and functional near-infrared spectroscopy (fNIRS) will be discussed in the context of recent work dealing with eating behavior, with a particular focus on obesity. In the second part of the review, non-invasive strategies to modulate food-related brain processes and functions will be presented. At the leading edge of non-invasive brain-based technologies is real-time fMRI (rtfMRI) neurofeedback, which is a powerful tool to better understand the complexity of human brain-behavior relationships. rtfMRI, alone or when combined with other techniques and tools such as EEG and cognitive therapy, could be used to alter neural plasticity and learned behavior to optimize and/or restore healthy cognition and eating behavior. Other promising non-invasive neuromodulation approaches being explored are repetitive transcranial magnetic stimulation (rTMS) and transcranial direct-current stimulation (tDCS). Converging evidence points at the value of

  16. Neuroimaging and neuromodulation approaches to study eating behavior and prevent and treat eating disorders and obesity

    PubMed Central

    Val-Laillet, D.; Aarts, E.; Weber, B.; Ferrari, M.; Quaresima, V.; Stoeckel, L.E.; Alonso-Alonso, M.; Audette, M.; Malbert, C.H.; Stice, E.

    2015-01-01

    Functional, molecular and genetic neuroimaging has highlighted the existence of brain anomalies and neural vulnerability factors related to obesity and eating disorders such as binge eating or anorexia nervosa. In particular, decreased basal metabolism in the prefrontal cortex and striatum as well as dopaminergic alterations have been described in obese subjects, in parallel with increased activation of reward brain areas in response to palatable food cues. Elevated reward region responsivity may trigger food craving and predict future weight gain. This opens the way to prevention studies using functional and molecular neuroimaging to perform early diagnostics and to phenotype subjects at risk by exploring different neurobehavioral dimensions of the food choices and motivation processes. In the first part of this review, advantages and limitations of neuroimaging techniques, such as functional magnetic resonance imaging (fMRI), positron emission tomography (PET), single photon emission computed tomography (SPECT), pharmacogenetic fMRI and functional near-infrared spectroscopy (fNIRS) will be discussed in the context of recent work dealing with eating behavior, with a particular focus on obesity. In the second part of the review, non-invasive strategies to modulate food-related brain processes and functions will be presented. At the leading edge of non-invasive brain-based technologies is real-time fMRI (rtfMRI) neurofeedback, which is a powerful tool to better understand the complexity of human brain–behavior relationships. rtfMRI, alone or when combined with other techniques and tools such as EEG and cognitive therapy, could be used to alter neural plasticity and learned behavior to optimize and/or restore healthy cognition and eating behavior. Other promising non-invasive neuromodulation approaches being explored are repetitive transcranial magnetic stimulation (rTMS) and transcranial direct-current stimulation (tDCS). Converging evidence points at the value of

  17. Institutional and Regulatory Economics of Electricity Market Reforms: the Evidence from India, Pakistan, Bangladesh, Nepal, and Sri Lanka

    NASA Astrophysics Data System (ADS)

    Singh, Bipulendu

    Five South Asian countries-- India, Pakistan, Bangladesh, Nepal and Sri Lanka -- embarked on electricity market reforms in the 1990's. The dissertation uses the framework of New Institutional Economics to assess the effects on electricity sector performance of both observables elements of reform (i.e. privatization, unbundling, establishment of independent regulatory agencies etc.) as well as the unobservable elements (informal beliefs, habit, norms and culture of the actors involved in reforms). The first part of the dissertation -- econometric analysis of the relationship between observable electricity market reform measures and performance indicators -- finds that for the most part electricity market reforms in South Asia are having a positive impact on the performance of the sector. This is particularly the case for reforms that have increased private sector participation in generation and distribution and have vertically unbundled utilities into generation, transmission and distribution entities. Many of the reforms are positively correlated with higher tariffs, indicating a cost to the consumers from the reforms. The relationship between independent regulation and performance indicators , however, is not established. The second part of the dissertation - analytical narrative of the reform experiences of Gujarat and Nepal -- examines the informal elements (such as beliefs, norms, culture) that motivate behavior and explains how and why reform outcomes differed in these two places. The dissertation finds that the strength of formal institutions rules and the nature of social norms and customs have a significant influence on the outcome of reforms. Aided by the strength of its formal institutional framework and more evolved social norms and customs that encouraged people to follow formal rules, reforms in the Indian state of Gujarat were a success. The weakness of the formal institutional framework and the predominance of relation-based norms and customs in

  18. Charge trapping and de-trapping in isolated CdSe/ZnS nanocrystals under an external electric field: Indirect evidence for a permanent dipole moment

    DOE PAGESBeta

    Zang, Huidong; Cristea, Mihail; Shen, Xuan; Liu, Mingzhao; Camino, Fernando; Cotlet, Mircea

    2015-08-05

    Single nanoparticle studies of charge trapping and de-trapping in core/shell CdSe/ZnS nanocrystals incorporated into an insulating matrix and subjected to an external electric field demonstrate the ability to reversibly modulate the exciton dynamics and photoluminescence blinking while providing indirect evidence for the existence of a permanent ground state dipole moment in such nanocrystals. A model assuming the presence of energetically deep charge traps physically aligned along the direction of the permanent dipole is proposed in order to explain the dynamics of nanocrystal blinking in the presence of a permanent dipole moment.

  19. Experimental evidence of cut-wire-induced enhanced transmission of transverse-electric fields through sub-wavelength slits in a thin metallic screen

    NASA Astrophysics Data System (ADS)

    di Gennaro, Emiliano; Gallina, Ilaria; Andreone, Antonello; Castaldi, Giuseppe; Galdi, Vincenzo

    2010-12-01

    Recent numerical studies have demonstrated the possibility of achieving substantial enhancements in the transmission of transverse-electric-polarized electromagnetic fields through subwavelength slits in a thin metallic screen by placing single or paired metallic cut-wire arrays at a close distance from the screen. In this Letter, we report on the first experimental evidence of such extraordinary transmission phenomena, via microwave (X/Ku-band) measurements on printed-circuit-board prototypes. Experimental results agree very well with full-wave numerical predictions, and indicate an intrinsic robustness of the enhanced transmission phenomena with respect to fabrication tolerances and experimental imperfections.

  20. Disturbance of emotion processing in frontotemporal dementia: a synthesis of cognitive and neuroimaging findings.

    PubMed

    Kumfor, Fiona; Piguet, Olivier

    2012-09-01

    Accurate processing of emotional information is a critical component of appropriate social interactions and interpersonal relationships. Disturbance of emotion processing is present in frontotemporal dementia (FTD) and is a clinical feature in two of the three subtypes: behavioural-variant FTD and semantic dementia. Emotion processing in progressive nonfluent aphasia, the third FTD subtype, is thought to be mostly preserved, although current evidence is scant. This paper reviews the literature on emotion recognition, reactivity and expression in FTD subtypes, although most studies focus on emotion recognition. The relationship between patterns of emotion processing deficits and patterns of neural atrophy are considered, by integrating evidence from recent neuroimaging studies. The review findings are discussed in the context of three contemporary theories of emotion processing: the limbic system model, the right hemisphere model and a multimodal system of emotion. Results across subtypes of FTD are most consistent with the multimodal system model, and support the presence of somewhat dissociable neural correlates for basic emotions, with strongest evidence for the emotions anger and sadness. Poor emotion processing is evident in all three subtypes, although deficits are more widespread than what would be predicted based on studies in healthy cohorts. Studies that include behavioural and imaging data are limited. Future investigations combining these approaches will help improve the understanding of the neural network underlying emotion processing. Presently, longitudinal investigations of emotion processing in FTD are lacking, and studies investigating emotion processing over time are critical to understand the clinical manifestations of disease progression in FTD. PMID:22577002

  1. A review of neuroimaging studies of young relatives of individuals with schizophrenia: a developmental perspective from schizotaxia to schizophrenia.

    PubMed

    Thermenos, H W; Keshavan, M S; Juelich, R J; Molokotos, E; Whitfield-Gabrieli, S; Brent, B K; Makris, N; Seidman, L J

    2013-10-01

    In an effort to identify the developing abnormalities preceding psychosis, Dr. Ming T. Tsuang and colleagues at Harvard expanded Meehl's concept of "schizotaxia," and examined brain structure and function in families affected by schizophrenia (SZ). Here, we systematically review genetic (familial) high-risk (HR) studies of SZ using magnetic resonance imaging (MRI), examine how findings inform models of SZ etiology, and suggest directions for future research. Neuroimaging studies of youth at HR for SZ through the age of 30 were identified through a MEDLINE (PubMed) search. There is substantial evidence of gray matter volume abnormalities in youth at HR compared to controls, with an accelerated volume reduction over time in association with symptoms and cognitive deficits. In structural neuroimaging studies, prefrontal cortex (PFC) alterations were the most consistently reported finding in HR. There was also consistent evidence of smaller hippocampal volume. In functional studies, hyperactivity of the right PFC during performance of diverse tasks with common executive demands was consistently reported. The only longitudinal fMRI study to date revealed increasing left middle temporal activity in association with the emergence of psychotic symptoms. There was preliminary evidence of cerebellar and default mode network alterations in association with symptoms. Brain abnormalities in structure, function and neurochemistry are observed in the premorbid period in youth at HR for SZ. Future research should focus on the genetic and environmental contributions to these alterations, determine how early they emerge, and determine whether they can be partially or fully remediated by innovative treatments. PMID:24132894

  2. Application of Dipole-dipole, Induced Polarization, and CSAMT Electrical Methods to Detect Evidence of an Underground Nuclear Explosion

    NASA Astrophysics Data System (ADS)

    Sweeney, J. J.; Felske, D.

    2013-12-01

    There is little experience with application of electrical methods that can be applied during the continuation period of an on-site inspection (OSI), one of the verification methods of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). In order add to such experience, we conducted controlled source audiomagnetotelluric (CSAMT), dipole-dipole resistivity, and induced polarization electrical measurements along three survey lines over and near to ground zero of an historic nuclear explosion. The presentation will provide details and results of the surveys, an assessment of application of the method toward the purposes of an OSI, and an assessment of the manpower and time requirements for data collection and processing that will impact OSI inspection team operations. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  3. An evidence for prompt electric field disturbance driven by changes in the solar wind density under northward IMF Bz condition

    NASA Astrophysics Data System (ADS)

    Rout, Diptiranjan; Chakrabarty, D.; Sekar, R.; Reeves, G. D.; Ruohoniemi, J. M.; Pant, Tarun K.; Veenadhari, B.; Shiokawa, K.

    2016-05-01

    Before the onset of a geomagnetic storm on 22 January 2012 (Ap = 24), an enhancement in solar wind number density from 10/cm3 to 22/cm3 during 0440-0510 UT under northward interplanetary magnetic field (IMF Bz) condition is shown to have enhanced the high-latitude ionospheric convection and also caused variations in the geomagnetic field globally. Conspicuous changes in ΔX are observed not only at longitudinally separated low-latitude stations over Indian (prenoon), South American (midnight), Japanese (afternoon), Pacific (afternoon) and African (morning) sectors but also at latitudinally separated stations located over high and middle latitudes. The latitudinal variation of the amplitude of the ΔX during 0440-0510 UT is shown to be consistent with the characteristics of prompt penetration electric field disturbances. Most importantly, the density pulse event caused enhancements in the equatorial electrojet strength and the peak height of the F layer (hmF2) over the Indian dip equatorial sector. Further, the concomitant enhancements in electrojet current and F layer movement over the dip equator observed during this space weather event suggest a common driver of prompt electric field disturbance at this time. Such simultaneous variations are found to be absent during magnetically quiet days. In absence of significant change in solar wind velocity and magnetospheric substorm activity, these observations point toward perceptible prompt electric field disturbance over the dip equator driven by the overcompression of the magnetosphere by solar wind density enhancement.

  4. Cognitive Improvement after Mild Traumatic Brain Injury Measured with Functional Neuroimaging during the Acute Period

    PubMed Central

    Wylie, Glenn R.; Freeman, Kalev; Thomas, Alex; Shpaner, Marina; OKeefe, Michael; Watts, Richard; Naylor, Magdalena R.

    2015-01-01

    controls. Increases in activation were greater in those mTBI subjects without cognitive recovery. As workload increased in mTBI subjects, activation increased in cortical regions in the right hemisphere. In summary, we found neuroimaging evidence for working memory deficits during the first week following mild traumatic brain injury. Subjects with persistent cognitive symptoms after mTBI had increased requirement for posterior cingulate activation to complete memory tasks at 1 week following a brain injury. These results provide insight into functional activation patterns during initial recovery from mTBI and expose the regional activation networks that may be involved in working memory deficits. PMID:25962067

  5. Cognitive Improvement after Mild Traumatic Brain Injury Measured with Functional Neuroimaging during the Acute Period.

    PubMed

    Wylie, Glenn R; Freeman, Kalev; Thomas, Alex; Shpaner, Marina; OKeefe, Michael; Watts, Richard; Naylor, Magdalena R

    2015-01-01

    controls. Increases in activation were greater in those mTBI subjects without cognitive recovery. As workload increased in mTBI subjects, activation increased in cortical regions in the right hemisphere. In summary, we found neuroimaging evidence for working memory deficits during the first week following mild traumatic brain injury. Subjects with persistent cognitive symptoms after mTBI had increased requirement for posterior cingulate activation to complete memory tasks at 1 week following a brain injury. These results provide insight into functional activation patterns during initial recovery from mTBI and expose the regional activation networks that may be involved in working memory deficits. PMID:25962067

  6. Neuroimaging training among neuropsychologists: A survey of the state of current training and recommendations for trainees

    PubMed Central

    Benitez, Andreana; Hassenstab, Jason; Bangen, Katherine J.

    2013-01-01

    Neuroimaging has gained widespread use in neuropsychological research and practice. However, there are neither established guidelines on how neuropsychologists might become competent researchers or consumers of neuroimaging data, nor any published studies describing the state of neuroimaging training among neuropsychologists. We report the results of two online surveys, one of 13 expert neuropsychologist-neuroimagers, whose responses informed the formulation of a second, larger survey to neuropsychologists-at-large that were a random selection of a third of the members of the International Neuropsychological Society and American Academy of Clinical Neuropsychology. 237 doctoral-level neuropsychologists, or 15.3% of potential participants, provided complete responses. Most respondents (69.2%) received training in neuroimaging, mostly at the post-doctoral level, largely through independent study, clinical conferences, instruction by clinical supervisors, and individualized mentoring, on topics such as neuroimaging modalities in neurology, neuroanatomy, and the appropriate information to glean from neuroradiology reports. Of the remaining respondents who did not receive training in neuroimaging, 64.4% indicated that such training would be very or extremely beneficial to one’s career as a neuropsychologist. Both neuropsychologist-neuroimagers and neuropsychologists-at-large provided specific recommendations for training. Findings from this initial effort will guide trainees who seek to develop competence in neuroimaging, and inform future formulations of neuropsychological training. PMID:24215451

  7. Multimodal neuroimaging based classification of autism spectrum disorder using anatomical, neurochemical, and white matter correlates

    PubMed Central

    Libero, Lauren E.; DeRamus, Thomas P.; Lahti, Adrienne C.; Deshpande, Gopikrishna; Kana, Rajesh K.

    2016-01-01

    Neuroimaging techniques, such as fMRI, structural MRI, diffusion tensor imaging (DTI), and proton magnetic resonance spectroscopy (1H-MRS) have uncovered evidence for widespread functional and anatomical brain abnormalities in autism spectrum disorder (ASD) suggesting it to be a system-wide neural systems disorder. Nevertheless, most previous studies have focused on examining one index of neuropathology through a single neuroimaging modality, and seldom using multiple modalities to examine the same cohort of individuals. The current study aims to bring together multiple brain imaging modalities (structural MRI, DTI, and 1H-MRS) to investigate the neural architecture in the same set of individuals (19 high-functioning adults with ASD and 18 typically developing (TD) peers). Morphometry analysis revealed increased cortical thickness in ASD participants, relative to typical controls, across the left cingulate, left pars opercularis of the inferior frontal gyrus, left inferior temporal cortex, and right precuneus, and reduced cortical thickness in right cuneus and right precentral gyrus. ASD adults also had reduced fractional anisotropy (FA) and increased radial diffusivity (RD) for two clusters on the forceps minor of the corpus callosum, revealed by DTI analyses. 1H-MRS results showed a reduction in the N-acetylaspartate/Creatine ratio in dorsal anterior cingulate cortex (dACC) in ASD participants. A decision tree classification analysis across the three modalities resulted in classification accuracy of 91.9% with FA, RD, and cortical thickness as key predictors. Examining the same cohort of adults with ASD and their TD peers, this study found alterations in cortical thickness, white matter (WM) connectivity, and neurochemical concentration in ASD. These findings underscore the potential for multimodal imaging to better inform on the neural characteristics most relevant to the disorder. PMID:25797658

  8. Internet and Gaming Addiction: A Systematic Literature Review of Neuroimaging Studies

    PubMed Central

    Kuss, Daria J.; Griffiths, Mark D.

    2012-01-01

    In the past decade, research has accumulated suggesting that excessive Internet use can lead to the development of a behavioral addiction. Internet addiction has been considered as a serious threat to mental health and the excessive use of the Internet has been linked to a variety of negative psychosocial consequences. The aim of this review is to identify all empirical studies to date that used neuroimaging techniques to shed light upon the emerging mental health problem of Internet and gaming addiction from a neuroscientific perspective. Neuroimaging studies offer an advantage over traditional survey and behavioral research because with this method, it is possible to distinguish particular brain areas that are involved in the development and maintenance of addiction. A systematic literature search was conducted, identifying 18 studies. These studies provide compelling evidence for the similarities between different types of addictions, notably substance-related addictions and Internet and gaming addiction, on a variety of levels. On the molecular level, Internet addiction is characterized by an overall reward deficiency that entails decreased dopaminergic activity. On the level of neural circuitry, Internet and gaming addiction led to neuroadaptation and structural changes that occur as a consequence of prolonged increased activity in brain areas associated with addiction. On a behavioral level, Internet and gaming addicts appear to be constricted with regards to their cognitive functioning in various domains. The paper shows that understanding the neuronal correlates associated with the development of Internet and gaming addiction will promote future research and will pave the way for the development of addiction treatment approaches. PMID:24961198

  9. Internet and gaming addiction: a systematic literature review of neuroimaging studies.

    PubMed

    Kuss, Daria J; Griffiths, Mark D

    2012-01-01

    In the past decade, research has accumulated suggesting that excessive Internet use can lead to the development of a behavioral addiction. Internet addiction has been considered as a serious threat to mental health and the excessive use of the Internet has been linked to a variety of negative psychosocial consequences. The aim of this review is to identify all empirical studies to date that used neuroimaging techniques to shed light upon the emerging mental health problem of Internet and gaming addiction from a neuroscientific perspective. Neuroimaging studies offer an advantage over traditional survey and behavioral research because with this method, it is possible to distinguish particular brain areas that are involved in the development and maintenance of addiction. A systematic literature search was conducted, identifying 18 studies. These studies provide compelling evidence for the similarities between different types of addictions, notably substance-related addictions and Internet and gaming addiction, on a variety of levels. On the molecular level, Internet addiction is characterized by an overall reward deficiency that entails decreased dopaminergic activity. On the level of neural circuitry, Internet and gaming addiction led to neuroadaptation and structural changes that occur as a consequence of prolonged increased activity in brain areas associated with addiction. On a behavioral level, Internet and gaming addicts appear to be constricted with regards to their cognitive functioning in various domains. The paper shows that understanding the neuronal correlates associated with the development of Internet and gaming addiction will promote future research and will pave the way for the development of addiction treatment approaches. PMID:24961198

  10. High-throughput neuroimaging-genetics computational infrastructure

    PubMed Central

    Dinov, Ivo D.; Petrosyan, Petros; Liu, Zhizhong; Eggert, Paul; Hobel, Sam; Vespa, Paul; Woo Moon, Seok; Van Horn, John D.; Franco, Joseph; Toga, Arthur W.

    2014-01-01

    Many contemporary neuroscientific investigations face significant challenges in terms of data management, computational processing, data mining, and results interpretation. These four pillars define the core infrastructure necessary to plan, organize, orchestrate, validate, and disseminate novel scientific methods, computational resources, and translational healthcare findings. Data management includes protocols for data acquisition, archival, query, transfer, retrieval, and aggregation. Computational processing involves the necessary software, hardware, and networking infrastructure required to handle large amounts of heterogeneous neuroimaging, genetics, clinical, and phenotypic data and meta-data. Data mining refers to the process of automatically extracting data features, characteristics and associations, which are not readily visible by human exploration of the raw dataset. Result interpretation includes scientific visualization, community validation of findings and reproducible findings. In this manuscript we describe the novel high-throughput neuroimaging-genetics computational infrastructure available at the Institute for Neuroimaging and Informatics (INI) and the Laboratory of Neuro Imaging (LONI) at University of Southern California (USC). INI and LONI include ultra-high-field and standard-field MRI brain scanners along with an imaging-genetics database for storing the complete provenance of the raw and derived data and meta-data. In addition, the institute provides a large number of software tools for image and shape analysis, mathematical modeling, genomic sequence processing, and scientific visualization. A unique feature of this architecture is the Pipeline environment, which integrates the data management, processing, transfer, and visualization. Through its client-server architecture, the Pipeline environment provides a graphical user interface for designing, executing, monitoring validating, and disseminating of complex protocols that utilize

  11. High-throughput neuroimaging-genetics computational infrastructure.

    PubMed

    Dinov, Ivo D; Petrosyan, Petros; Liu, Zhizhong; Eggert, Paul; Hobel, Sam; Vespa, Paul; Woo Moon, Seok; Van Horn, John D; Franco, Joseph; Toga, Arthur W

    2014-01-01

    Many contemporary neuroscientific investigations face significant challenges in terms of data management, computational processing, data mining, and results interpretation. These four pillars define the core infrastructure necessary to plan, organize, orchestrate, validate, and disseminate novel scientific methods, computational resources, and translational healthcare findings. Data management includes protocols for data acquisition, archival, query, transfer, retrieval, and aggregation. Computational processing involves the necessary software, hardware, and networking infrastructure required to handle large amounts of heterogeneous neuroimaging, genetics, clinical, and phenotypic data and meta-data. Data mining refers to the process of automatically extracting data features, characteristics and associations, which are not readily visible by human exploration of the raw dataset. Result interpretation includes scientific visualization, community validation of findings and reproducible findings. In this manuscript we describe the novel high-throughput neuroimaging-genetics computational infrastructure available at the Institute for Neuroimaging and Informatics (INI) and the Laboratory of Neuro Imaging (LONI) at University of Southern California (USC). INI and LONI include ultra-high-field and standard-field MRI brain scanners along with an imaging-genetics database for storing the complete provenance of the raw and derived data and meta-data. In addition, the institute provides a large number of software tools for image and shape analysis, mathematical modeling, genomic sequence processing, and scientific visualization. A unique feature of this architecture is the Pipeline environment, which integrates the data management, processing, transfer, and visualization. Through its client-server architecture, the Pipeline environment provides a graphical user interface for designing, executing, monitoring validating, and disseminating of complex protocols that utilize

  12. Neuroimaging and Neurodevelopmental Outcome in Extremely Preterm Infants

    PubMed Central

    Barnes, Patrick D.; Bulas, Dorothy; Slovis, Thomas L.; Finer, Neil N.; Wrage, Lisa A.; Das, Abhik; Tyson, Jon E.; Stevenson, David K.; Carlo, Waldemar A.; Walsh, Michele C.; Laptook, Abbot R.; Yoder, Bradley A.; Van Meurs, Krisa P.; Faix, Roger G.; Rich, Wade; Newman, Nancy S.; Cheng, Helen; Heyne, Roy J.; Vohr, Betty R.; Acarregui, Michael J.; Vaucher, Yvonne E.; Pappas, Athina; Peralta-Carcelen, Myriam; Wilson-Costello, Deanne E.; Evans, Patricia W.; Goldstein, Ricki F.; Myers, Gary J.; Poindexter, Brenda B.; McGowan, Elisabeth C.; Adams-Chapman, Ira; Fuller, Janell; Higgins, Rosemary D.

    2015-01-01

    BACKGROUND: Extremely preterm infants are at risk for neurodevelopmental impairment (NDI). Early cranial ultrasound (CUS) is usual practice, but near-term brain MRI has been reported to better predict outcomes. We prospectively evaluated MRI white matter abnormality (WMA) and cerebellar lesions, and serial CUS adverse findings as predictors of outcomes at 18 to 22 months’ corrected age. METHODS: Early and late CUS, and brain MRI were read by masked central readers, in a large cohort (n = 480) of infants <28 weeks’ gestation surviving to near term in the Neonatal Research Network. Outcomes included NDI or death after neuroimaging, and significant gross motor impairment or death, with NDI defined as cognitive composite score <70, significant gross motor impairment, and severe hearing or visual impairment. Multivariable models evaluated the relative predictive value of neuroimaging while controlling for other factors. RESULTS: Of 480 infants, 15 died and 20 were lost. Increasing severity of WMA and significant cerebellar lesions on MRI were associated with adverse outcomes. Cerebellar lesions were rarely identified by CUS. In full multivariable models, both late CUS and MRI, but not early CUS, remained independently associated with NDI or death (MRI cerebellar lesions: odds ratio, 3.0 [95% confidence interval: 1.3–6.8]; late CUS: odds ratio, 9.8 [95% confidence interval: 2.8–35]), and significant gross motor impairment or death. In models that did not include late CUS, MRI moderate-severe WMA was independently associated with adverse outcomes. CONCLUSIONS: Both late CUS and near-term MRI abnormalities were associated with outcomes, independent of early CUS and other factors, underscoring the relative prognostic value of near-term neuroimaging. PMID:25554820

  13. Multiple brain atlas database and atlas-based neuroimaging system.

    PubMed

    Nowinski, W L; Fang, A; Nguyen, B T; Raphel, J K; Jagannathan, L; Raghavan, R; Bryan, R N; Miller, G A

    1997-01-01

    For the purpose of developing multiple, complementary, fully labeled electronic brain atlases and an atlas-based neuroimaging system for analysis, quantification, and real-time manipulation of cerebral structures in two and three dimensions, we have digitized, enhanced, segmented, and labeled the following print brain atlases: Co-Planar Stereotaxic Atlas of the Human Brain by Talairach and Tournoux, Atlas for Stereotaxy of the Human Brain by Schaltenbrand and Wahren, Referentially Oriented Cerebral MRI Anatomy by Talairach and Tournoux, and Atlas of the Cerebral Sulci by Ono, Kubik, and Abernathey. Three-dimensional extensions of these atlases have been developed as well. All two- and three-dimensional atlases are mutually preregistered and may be interactively registered with an actual patient's data. An atlas-based neuroimaging system has been developed that provides support for reformatting, registration, visualization, navigation, image processing, and quantification of clinical data. The anatomical index contains about 1,000 structures and over 400 sulcal patterns. Several new applications of the brain atlas database also have been developed, supported by various technologies such as virtual reality, the Internet, and electronic publishing. Fusion of information from multiple atlases assists the user in comprehensively understanding brain structures and identifying and quantifying anatomical regions in clinical data. The multiple brain atlas database and atlas-based neuroimaging system have substantial potential impact in stereotactic neurosurgery and radiotherapy by assisting in visualization and real-time manipulation in three dimensions of anatomical structures, in quantitative neuroradiology by allowing interactive analysis of clinical data, in three-dimensional neuroeducation, and in brain function studies. PMID:9148878

  14. NPAS3 variants in schizophrenia: a neuroimaging study

    PubMed Central

    2014-01-01

    Background This research is a one-site neuroimaging component of a two-site genetic study involving patients with schizophrenia at early and later stages of illness. Studies support a role for the neuronal Per-Arnt-Sim 3 (NPAS3) gene in processes that are essential for normal brain development. Specific NPAS3 variants have been observed at an increased frequency in schizophrenia. In humans, NPAS3 protein was detected in the hippocampus from the first trimester of gestation. In addition, NPAS3 protein levels were reduced in the dorsolateral prefrontal cortex of some patients with schizophrenia. Npas3 knockout mice display behavioural, neuroanatomical and structural changes with associated severe reductions in neural precursor cell proliferation in the hippocampal dentate gyrus. This study will evaluate the hypothesis that the severe reductions in neural precursor cell proliferation in the dentate gyrus will be present to some degree in patients carrying schizophrenia-associated NPAS3 variants and less so in other patients. Methods/Design Patients enrolled in the larger genetic study (n = 150) will be invited to participate in this neuroimaging arm. The genetic data will be used to ensure a sample size of 45 participants in each genetic subgroup of patients (with and without NPAS3 variants). In addition, we will recruit 60 healthy controls for acquisition of normative data. The following neuroimaging measures will be acquired from the medial temporal region: a) an index of the microcellular environment; b) a macro-structural volumetric measure of the hippocampus; and c) concentration levels of N-acetylaspartate, a marker of neuronal health. Discussion This study will help to establish the contribution of the NPAS3 gene and its variants to brain tissue abnormalities in schizophrenia. Given the genetic and phenotypic heterogeneity of the disorder and the large variation in outcomes, the identification of biological subgroups may in future support tailoring of treatment

  15. Accelerating Neuroimage Registration through Parallel Computation of Similarity Metric

    PubMed Central

    Luo, Yun-gang; Liu, Ping; Shi, Lin; Luo, Yishan; Yi, Lei; Li, Ang; Qin, Jing; Heng, Pheng-Ann; Wang, Defeng

    2015-01-01

    Neuroimage registration is crucial for brain morphometric analysis and treatment efficacy evaluation. However, existing advanced registration algorithms such as FLIRT and ANTs are not efficient enough for clinical use. In this paper, a GPU implementation of FLIRT with the correlation ratio (CR) as the similarity metric and a GPU accelerated correlation coefficient (CC) calculation for the symmetric diffeomorphic registration of ANTs have been developed. The comparison with their corresponding original tools shows that our accelerated algorithms can greatly outperform the original algorithm in terms of computational efficiency. This paper demonstrates the great potential of applying these registration tools in clinical applications. PMID:26352412

  16. Multimodal Neuroimaging-Informed Clinical Applications in Neuropsychiatric Disorders.

    PubMed

    O'Halloran, Rafael; Kopell, Brian H; Sprooten, Emma; Goodman, Wayne K; Frangou, Sophia

    2016-01-01

    Recent advances in neuroimaging data acquisition and analysis hold the promise to enhance the ability to make diagnostic and prognostic predictions and perform treatment planning in neuropsychiatric disorders. Prior research using a variety of types of neuroimaging techniques has confirmed that neuropsychiatric disorders are associated with dysfunction in anatomical and functional brain circuits. We first discuss current challenges associated with the identification of reliable neuroimaging markers for diagnosis and prognosis in mood disorders and for neurosurgical treatment planning for deep brain stimulation (DBS). We then present data on the use of neuroimaging for the diagnosis and prognosis of mood disorders and for DBS treatment planning. We demonstrate how multivariate analyses of functional activation and connectivity parameters can be used to differentiate patients with bipolar disorder from those with major depressive disorder and non-affective psychosis. We also present data on connectivity parameters that mediate acute treatment response in affective and non-affective psychosis. We then focus on precision mapping of functional connectivity in native space. We describe the benefits of integrating anatomical fiber reconstruction with brain functional parameters and cortical surface measures to derive anatomically informed connectivity metrics within the morphological context of each individual brain. We discuss how this approach may be particularly promising in psychiatry, given the clinical and etiological heterogeneity of the disorders, and particularly in treatment response prediction and planning. Precision mapping of connectivity is essential for DBS. In DBS, treatment electrodes are inserted into positions near key gray matter nodes within the circuits considered relevant to disease expression. However, targeting white matter tracts that underpin connectivity within these circuits may increase treatment efficacy and tolerability therefore relevant

  17. Presurgical multimodality neuroimaging analysis for complex partial seizures

    NASA Astrophysics Data System (ADS)

    Wong, Stephen T. C.; Hoo, Kent S., Jr.; Knowlton, Robert C.; Laxer, Kenneth D.; Hawkins, Randall A.; Rowley, Howard A.; Weiner, Michael W.

    1998-07-01

    Surgical treatment of patients suffering from complex partial seizures requires the localization of the epileptogenic zone for surgical resection. Currently, clinicians utilize electroencephalography (EEG), psychological tests, and various neuroimaging modalities together to determine the location of this zone. We investigate the use of positron emission tomography (PET), magnetic resonance imaging (MRI), and magnetic resonance spectroscopy (MRS) in the presurgical workup and analysis of patients with complex partial seizures. The results of imaging studies of 25 patients are compared for lateralization accuracy and relative concordance.

  18. Multimodal Neuroimaging-Informed Clinical Applications in Neuropsychiatric Disorders

    PubMed Central

    O’Halloran, Rafael; Kopell, Brian H.; Sprooten, Emma; Goodman, Wayne K.; Frangou, Sophia

    2016-01-01

    Recent advances in neuroimaging data acquisition and analysis hold the promise to enhance the ability to make diagnostic and prognostic predictions and perform treatment planning in neuropsychiatric disorders. Prior research using a variety of types of neuroimaging techniques has confirmed that neuropsychiatric disorders are associated with dysfunction in anatomical and functional brain circuits. We first discuss current challenges associated with the identification of reliable neuroimaging markers for diagnosis and prognosis in mood disorders and for neurosurgical treatment planning for deep brain stimulation (DBS). We then present data on the use of neuroimaging for the diagnosis and prognosis of mood disorders and for DBS treatment planning. We demonstrate how multivariate analyses of functional activation and connectivity parameters can be used to differentiate patients with bipolar disorder from those with major depressive disorder and non-affective psychosis. We also present data on connectivity parameters that mediate acute treatment response in affective and non-affective psychosis. We then focus on precision mapping of functional connectivity in native space. We describe the benefits of integrating anatomical fiber reconstruction with brain functional parameters and cortical surface measures to derive anatomically informed connectivity metrics within the morphological context of each individual brain. We discuss how this approach may be particularly promising in psychiatry, given the clinical and etiological heterogeneity of the disorders, and particularly in treatment response prediction and planning. Precision mapping of connectivity is essential for DBS. In DBS, treatment electrodes are inserted into positions near key gray matter nodes within the circuits considered relevant to disease expression. However, targeting white matter tracts that underpin connectivity within these circuits may increase treatment efficacy and tolerability therefore relevant

  19. Sporadic Cerebral Amyloid Angiopathy: Pathophysiology, Neuroimaging Features, and Clinical Implications.

    PubMed

    Boulouis, Gregoire; Charidimou, Andreas; Greenberg, Steven M

    2016-06-01

    Sporadic cerebral amyloid angiopathy is a small vessel disorder defined pathologically by progressive amyloid deposition in the walls of cortical and leptomeningeal vessels resulting from disruption of a complex balance between production, circulation, and clearance of amyloid-β peptide (Aβ) in the brain. Cerebral amyloid angiopathy is a major cause of lobar symptomatic intracerebral hemorrhage, transient focal neurologic episodes, and a key contributor to vascular cognitive impairment. The mechanisms and consequences of amyloid-β deposition at the pathological level and its neuroimaging manifestations, clinical consequences, and implications for patient care are addressed in this review. PMID:27214698

  20. The Appropriate Use of Neuroimaging in the Diagnostic Work-Up of Dementia

    PubMed Central

    2014-01-01

    Background Diagnosis of dementia is challenging and requires both ruling out potentially treatable underlying causes and ruling in a diagnosis of dementia subtype to manage patients and suitably plan for the future. Objectives This analysis sought to determine the appropriate use of neuroimaging during the diagnostic work-up of dementia, including indications for neuroimaging and comparative accuracy of alternative technologies. Data Sources A literature search was performed using Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid Embase, the Wiley Cochrane Library, and the Centre for Reviews and Dissemination database, for studies published between 2000 and 2013. Review Methods Data on diagnostic accuracy and impact on clinical decision making were abstracted from included studies. Quality of evidence was assessed using GRADE. Results The search yielded 5,374 citations and 15 studies were included. Approximately 10% of dementia cases are potentially treatable, though less than 1% reverse partially or fully. Neither prediction rules nor clinical indications reliably select the subset of patients who will likely benefit from neuroimaging. Clinical utility is highest in ambiguous cases or where dementia may be mixed, and lowest for clinically diagnosed Alzheimer disease or clinically excluded vascular dementia. There is a lack of evidence that MRI is superior to CT in detecting a vascular component to dementia. Accuracy of structural imaging is moderate to high for discriminating different types of dementia. Limitations There was significant heterogeneity in estimates of diagnostic accuracy, which often prohibited a statistical summary of findings. The quality of data reported by studies prohibited calculation of likelihood ratios in the present analysis. No studies from primary care were found; thus, generalizability beyond tertiary care settings may be limited. Conclusions A diagnosis of reversible dementia is rare. Imaging has the most

  1. Behavioral, computational, and neuroimaging studies of acquired apraxia of speech

    PubMed Central

    Ballard, Kirrie J.; Tourville, Jason A.; Robin, Donald A.

    2014-01-01

    A critical examination of speech motor control depends on an in-depth understanding of network connectivity associated with Brodmann areas 44 and 45 and surrounding cortices. Damage to these areas has been associated with two conditions—the speech motor programming disorder apraxia of speech (AOS) and the linguistic/grammatical disorder of Broca’s aphasia. Here we focus on AOS, which is most commonly associated with damage to posterior Broca’s area (BA) and adjacent cortex. We provide an overview of our own studies into the nature of AOS, including behavioral and neuroimaging methods, to explore components of the speech motor network that are associated with normal and disordered speech motor programming in AOS. Behavioral, neuroimaging, and computational modeling studies are indicating that AOS is associated with impairment in learning feedforward models and/or implementing feedback mechanisms and with the functional contribution of BA6. While functional connectivity methods are not yet routinely applied to the study of AOS, we highlight the need for focusing on the functional impact of localized lesions throughout the speech network, as well as larger scale comparative studies to distinguish the unique behavioral and neurological signature of AOS. By coupling these methods with neural network models, we have a powerful set of tools to improve our understanding of the neural mechanisms that underlie AOS, and speech production generally. PMID:25404911

  2. New frontiers in neuroimaging applications to inborn errors of metabolism

    PubMed Central

    Prust, Morgan J.; Gropman, Andrea L.; Hauser, Natalie

    2013-01-01

    Most inborn errors of metabolism (IEMs) are associated with potential for injury to the developing central nervous system resulting in chronic encephalopathy, though the etiopathophysiology of neurological injury have not been fully established in many disorders. Shared mechanisms can be envisioned such as oxidative injury due to over-activation of N-Methyl-D-Aspartate (NMDA) receptors with subsequent glutamatergic damage, but other causes such as energy depletion or inflammation are possible. Neuroimaging has emerged as a powerful clinical and research tool for studying the brain in a noninvasive manner. Several platforms exist to study neural networks underlying cognitive processes, white matter/myelin microstructure, and cerebral metabolism in vivo. The scope and limitations of these methods will be discussed in the context of valuable information they provide in the study and management of selected inborn errors of metabolism. This review is not meant to be an exhaustive coverage of diagnostic findings on MRI in multiple IEMs, but rather to illustrate how neuroimaging modalities beyond T1 and T2 images, can add depth to an understanding of the underlying brain changes evoked by the selected IEMs. Emphasis will be placed on techniques that are available in the clinical setting. Though technically complex, many of these modalities have moved – or soon will – to the clinical arena. PMID:21778100

  3. Understanding face perception by means of prosopagnosia and neuroimaging.

    PubMed

    Rossion, Bruno

    2014-01-01

    Understanding the human neuro-anatomy of face recognition is a long-standing goal of Cognitive Neuroscience. Studies of patients with face recognition impairment following brain damage (i.e., acquired prosopagnosia) have revealed the specificity of face recognition, the importance and nature of holistic/configural perception of individual faces, and the distribution of this function in the ventral occipito-temporal (VOT) cortex, with a right hemispheric dominance. Yet, neuroimaging studies in this field have essentially focused on a single face-selective area of the VOT and underestimated the right hemisphere superiority. Findings in these studies have also been taken as supporting a hierarchical view of face perception, according to which a face is decomposed into parts in early face-selective areas, these parts being subsequently integrated into a whole representation in higher-order areas. This review takes a historical and current perspective on the study of acquired prosopagnosia and neuroimaging that challenges this latter view. It argues for a combination of these methods, an approach suggesting a coarse-to-fine emergence of the holistic face percept in a non-hierarchical network of cortical face-selective areas. PMID:24896206

  4. Neuroimaging in the Diagnostic Evaluation of Eye Pain.

    PubMed

    Szatmáry, Gabriella

    2016-09-01

    Ocular or eye pain is a frequent complaint encountered not only by eye care providers but neurologists. Isolated eye pain is non-specific and non-localizing; therefore, it poses significant differential diagnostic problems. A wide range of neurologic and ophthalmic disorders may cause pain in, around, or behind the eye. These include ocular and orbital diseases and primary and secondary headaches. In patients presenting with an isolated and chronic eye pain, neuroimaging is usually normal. However, at the beginning of a disease process or in low-grade disease, the eye may appear "quiet," misleading a provider lacking familiarity with underlying disorders and high index of clinical suspicion. Delayed diagnosis of some neuro-ophthalmic causes of eye pain could result in significant neurologic and ophthalmic morbidity, conceivably even mortality. This article reviews some recent advances in imaging of the eye, the orbit, and the brain, as well as research in which neuroimaging has advanced the discovery of the underlying pathophysiology and the complex differential diagnosis of eye pain. PMID:27474094

  5. The use of neuroimaging in the diagnosis of mitochondrial disease.

    PubMed

    Friedman, Seth D; Shaw, Dennis W W; Ishak, Gisele; Gropman, Andrea L; Saneto, Russell P

    2010-01-01

    Mutations in nuclear and mitochondrial DNA impacting mitochondrial function result in disease manifestations ranging from early death to abnormalities in all major organ systems and to symptoms that can be largely confined to muscle fatigue. The definitive diagnosis of a mitochondrial disorder can be difficult to establish. When the constellation of symptoms is suggestive of mitochondrial disease, neuroimaging features may be diagnostic and suggestive, can help direct further workup, and can help to further characterize the underlying brain abnormalities. Magnetic resonance imaging changes may be nonspecific, such as atrophy (both general and involving specific structures, such as cerebellum), more suggestive of particular disorders such as focal and often bilateral lesions confined to deep brain nuclei, or clearly characteristic of a given disorder such as stroke-like lesions that do not respect vascular boundaries in mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episode (MELAS). White matter hyperintensities with or without associated gray matter involvement may also be observed. Across patients and discrete disease subtypes (e.g., MELAS, Leigh syndrome, etc.), patterns of these features are helpful for diagnosis. However, it is also true that marked variability in expression occurs in all mitochondrial disease subtypes, illustrative of the complexity of the disease process. The present review summarizes the role of neuroimaging in the diagnosis and characterization of patients with suspected mitochondrial disease. PMID:20818727

  6. A System for Addressing Incidental Findings in Neuroimaging Research

    PubMed Central

    Cramer, Steven C.; Wu, Jennifer; Hanson, Joseph A.; Nouri, Sarvenaz; Karnani, Diraj; Chuang, Tony M.; Le, Vu

    2011-01-01

    When healthy subjects undergo brain imaging, incidental findings are not rare. The optimal response to such findings has been the focus of considerable discussion. The current report describes the operations and results of a system that provides review of incidental findings by an appropriate medical professional. A web-based system was created whereby investigators performing brain MRI scans on healthy subjects could refer images with suspected concerns to a board certified radiologist who had a Certificate of Added Qualification in Neuroradiology. The specific details of this system are described. Among 27 scans suspected by an investigator of having a significant finding, all but one were referred by a researcher with a PhD. The most common concerns described by these investigators were for the possible presence of a cyst or of enlarged ventricles. The most common findings reported by the radiologist were Virchow-Robin spaces and cysts. Findings were generally of low clinical significance, with 1 major exception. Identifying the optimal response to incidental findings in neuroimaging research remains a challenge. The current report describes a system for providing expert assistance and so addresses these issues in the setting of suspected incidental findings. To our knowledge the current system is the first to provide a specific means for evaluation of incidental findings in neuroimaging research. PMID:21224007

  7. Visualization of group inference data in functional neuroimaging.

    PubMed

    Gläscher, Jan

    2009-01-01

    While thresholded statistical parametric maps can convey an accurate account for the location and spatial extent of an effect in functional neuroimaging studies, their use is somewhat limited for characterizing more complex experimental effects, such as interactions in a factorial design. The resulting necessity for plotting the underlying data has long been recognized. Statistical Parametric Mapping (SPM) is a widely used software package for analyzing functional neuroimaging data that offers a variety of options for visualizing data from first level analyses. However, nowadays, the thrust of the statistical inference lies at the second level thus allowing for population inference. Unfortunately, the options for visualizing data from second level analyses are quite sparse. rfxplot is a new toolbox designed to alleviate this problem by providing a comprehensive array of options for plotting data from within second level analyses in SPM. These include graphs of average effect sizes (across subjects), averaged fitted responses and event-related blood oxygen level-dependent (BOLD) time courses. All data are retrieved from the underlying first level analyses and voxel selection can be tailored to the maximum effect in each subject within a defined search volume. All plot configurations can be easily configured via a graphical user-interface as well as non-interactively via a script. The large variety of plot options renders rfxplot suitable both for data exploration as well as producing high-quality figures for publications. PMID:19140033

  8. Neuroimaging correlates of pharmacological and psychological treatments for specific phobia.

    PubMed

    Linares, Ila M; Chags, Marcos H N; Machado-de-Sousa, João P; Crippa, José A S; Hallak, Jaime E C

    2014-01-01

    Specific phobia is an anxiety disorder characterized by irrational fear and avoidance of specific things or situations, interfering significantly with the patients' daily life. Treatment for the disorder consists of both pharmacological and psychological approaches, mainly cognitive behavioral therapy (CBT). Neuroimaging techniques have been used in an attempt to improve our understanding of the neurobiology of SP and of the effects of treatment options available. This review describes the design and results of eight articles investigating the neuroimaging correlates of pharmacological and psychological treatments for SP. The studies show that CBT is effective in SP, leading to a reduction of anxiety symptoms that is accompanied by functional alterations in the brain. The results of pharmacological interventions for SP are less uniform, but suggest that the partial agonist of the NMDA (N-methyl D-aspartate) receptor DCS (D-cycloserine) can be used in combination with psychotherapy techniques for the achievement of quicker treatment response and that DCS modulates the function of structures implicated in the neurobiology of SP. Further research should explore the augmentation of CBT treatment with DCS in controlled trials. PMID:24923351

  9. A multi-subject, multi-modal human neuroimaging dataset

    PubMed Central

    Wakeman, Daniel G; Henson, Richard N

    2015-01-01

    We describe data acquired with multiple functional and structural neuroimaging modalities on the same nineteen healthy volunteers. The functional data include Electroencephalography (EEG), Magnetoencephalography (MEG) and functional Magnetic Resonance Imaging (fMRI) data, recorded while the volunteers performed multiple runs of hundreds of trials of a simple perceptual task on pictures of familiar, unfamiliar and scrambled faces during two visits to the laboratory. The structural data include T1-weighted MPRAGE, Multi-Echo FLASH and Diffusion-weighted MR sequences. Though only from a small sample of volunteers, these data can be used to develop methods for integrating multiple modalities from multiple runs on multiple participants, with the aim of increasing the spatial and temporal resolution above that of any one modality alone. They can also be used to integrate measures of functional and structural connectivity, and as a benchmark dataset to compare results across the many neuroimaging analysis packages. The data are freely available from https://openfmri.org/. PMID:25977808

  10. Structural Neuroimaging Markers of Cognitive Decline in Parkinson's Disease

    PubMed Central

    Hanganu, Alexandru; Monchi, Oury

    2016-01-01

    Cognitive impairment in patients with Parkinson's disease is a major challenge since it has been established that 25 to 40% of patients will develop cognitive impairment early in the disease. Furthermore, it has been reported that up to 80% of Parkinsonian patients will eventually develop dementia. Thus, it is important to improve the diagnosing procedures in order to detect cognitive impairment at early stages of development and to delay as much as possible the developing of dementia. One major challenge is that patients with mild cognitive impairment exhibit measurable cognitive deficits according to recently established criteria, yet those deficits are not severe enough to interfere with daily living, hence being avoided by patients, and might be overseen by clinicians. Recent advances in neuroimaging brain analysis allowed the establishment of several anatomical markers that have the potential to be considered for early detection of cognitive impairment in Parkinsonian patients. This review aims to outline the neuroimaging possibilities in diagnosing cognitive impairment in patients with Parkinson's disease and to take into consideration the near-future possibilities of their implementation into clinical practice. PMID:27190672

  11. Neuroimaging studies of alexithymia: physical, affective, and social perspectives

    PubMed Central

    2013-01-01

    Alexithymia refers to difficulty in identifying and expressing one’s emotions, and it is related to disturbed emotional regulation. It was originally proposed as a personality trait that plays a central role in psychosomatic diseases. This review of neuroimaging studies on alexithymia suggests that alexithymia is associated with reduced neural responses to emotional stimuli from the external environment, as well as with reduced activity during imagery, in the limbic and paralimbic areas (i.e., amygdala, insula, anterior/posterior cingulate cortex). In contrast, alexithymia is also known to be associated with enhanced neural activity in somatosensory and sensorimotor regions, including the insula. Moreover, neural activity in the medial, prefrontal, and insula cortex was lowered when people with alexithymia were involved in social tasks. Because most neuroimaging studies have been based on sampling by self-reported questionnaires, the contrasted features of neural activities in response to internal and external emotional stimuli need to be elucidated. The social and emotional responses of people with alexithymia are discussed and recommendations for future research are presented. PMID:23537323

  12. Transcranial magnetic stimulation in schizophrenia: the contribution of neuroimaging.

    PubMed

    Du, Zhong-de; Wang, R; Prakash, Ravi; Chaudhury, S; Dayananda, G

    2012-01-01

    At the most basic level, the Transcranial Magnetic Stimulation(TMS) is a neuro-scientific tool that exerts its action by influencing the neo-cortical functions. However, in-spite of so many well-evidenced roles of TMS in neuropsychiatric conditions, its exact mechanism of action remains to be known. More intriguing are its therapeutic effects in Schizophrenia at the Cerebral-level. In this review, we adopt a neuro-imaging approach for this exploration. We review the present literature for the studies in Schizophrenia which have used a combination of rTMS with 1) Electroenchephalogram (EEG) 2)The functional Magnetic Resonance Imaging (fMRI) and the 3) Positron Emission Tomography (PET)/ Single-Photon Emission Computed Tomography. The TMS-EEG combination provides direct effects of TMS on the electro- magnetic field (EMF) of brain. The TMS-fMRI/PET/SPECT combinations are very effective in exploring the functional connectivity in brains of Schizophrenia patients as well as in performing rTMS guided neuro-navigation. Our review suggests that TMS combined with other neuroimaging modalities are needed for a better clarification of its neural actions. PMID:23409741

  13. Very poor outcome schizophrenia: Clinical and neuroimaging aspects

    PubMed Central

    Mitelman, Serge A.; Buchsbaum, Monte S.

    2009-01-01

    In spite of significant advances in treatment of patients with schizophrenia and continued efforts towards their deinstitutionalization, a considerable group of patients remain chronically hospitalized or otherwise dependent on others for basic necessities of life. It has been proposed that these patients belong to a distinct etiopathological subgroup, termed Kraepelinian, whose course of illness may be progressive and resistant to treatment. Indeed, longitudinal studies appear to show that elderly Kraepelinian patients follow a course of rapid cognitive and functional deterioration, commensurate with a dementing process, and that their poor functional status is closely correlated with the cognitive deterioration. Recent neuroimaging studies described a pattern of posteriorization of grey and white matter deficits with poor outcome in schizophrenia, and produced a constellation of findings implicating primary processing of visual and auditory information as central to the impaired functional status in this patient group. These studies are summarized in detail in this review and future directions for neuroimaging assessment of very poor outcome patients with schizophrenia are suggested. PMID:17671868

  14. Neuroimaging biomarkers for early drug development in schizophrenia.

    PubMed

    Tregellas, Jason R

    2014-07-15

    Given the relative inability of currently available antipsychotic treatments to adequately provide sustained recovery and improve quality of life for patients with schizophrenia, new treatment strategies are urgently needed. One way to improve the therapeutic development process may be an increased use of biomarkers in early clinical trials. Reliable biomarkers that reflect aspects of disease pathophysiology can be used to determine if potential treatment strategies are engaging their desired biological targets. This review evaluates three potential neuroimaging biomarkers: hippocampal hyperactivity, gamma-band deficits, and default network abnormalities. These deficits have been widely replicated in the illness, correlate with measures of positive symptoms, are consistent with models of disease pathology, and have shown initial promise as biomarkers of biological response in early studies of potential treatment strategies. Two key features of these deficits, and a guiding rationale for the focus of this review, are that the deficits are not dependent upon patients' performance of specific cognitive tasks and they have analogues in animal models of schizophrenia, greatly increasing their appeal for use as biomarkers. Using neuroimaging biomarkers such as those proposed here to establish early in the therapeutic development process if treatment strategies are having their intended biological effect in humans may facilitate development of new treatments for schizophrenia. PMID:24094513

  15. Neuroimaging Biomarkers for Early Drug Development in Schizophrenia

    PubMed Central

    Tregellas, Jason R.

    2013-01-01

    Given the relative inability of currently available antipsychotic treatments to adequately provide sustained recovery and improve quality of life for patients with schizophrenia, new treatment strategies are urgently needed. One way to improve the therapeutic development process may be an increased use of biomarkers in early clinical trials. Reliable biomarkers that reflect aspects of disease pathophysiology can be used to determine if potential treatment strategies are engaging their desired biological targets. This review evaluates three potential neuroimaging biomarkers: hippocampal hyperactivity, gamma-band deficits and default network abnormalities. These deficits have been widely replicated in the illness, correlate with measures of positive symptoms, are consistent with models of disease pathology, and have shown initial promise as biomarkers of biological response in early studies of potential treatment strategies. Two key features of these deficits, and a guiding rational for the focus of this review, is that the deficits are not dependent upon patients' performance of specific cognitive tasks, and have analogues in animal models of schizophrenia, greatly increasing their appeal for use as biomarkers. Using neuroimaging biomarkers such as those proposed here to establish early in the therapeutic development process if treatment strategies are having their intended biological effect in humans may facilitate development of new treatments for schizophrenia. PMID:24094513

  16. Behavioral, computational, and neuroimaging studies of acquired apraxia of speech.

    PubMed

    Ballard, Kirrie J; Tourville, Jason A; Robin, Donald A

    2014-01-01

    A critical examination of speech motor control depends on an in-depth understanding of network connectivity associated with Brodmann areas 44 and 45 and surrounding cortices. Damage to these areas has been associated with two conditions-the speech motor programming disorder apraxia of speech (AOS) and the linguistic/grammatical disorder of Broca's aphasia. Here we focus on AOS, which is most commonly associated with damage to posterior Broca's area (BA) and adjacent cortex. We provide an overview of our own studies into the nature of AOS, including behavioral and neuroimaging methods, to explore components of the speech motor network that are associated with normal and disordered speech motor programming in AOS. Behavioral, neuroimaging, and computational modeling studies are indicating that AOS is associated with impairment in learning feedforward models and/or implementing feedback mechanisms and with the functional contribution of BA6. While functional connectivity methods are not yet routinely applied to the study of AOS, we highlight the need for focusing on the functional impact of localized lesions throughout the speech network, as well as larger scale comparative studies to distinguish the unique behavioral and neurological signature of AOS. By coupling these methods with neural network models, we have a powerful set of tools to improve our understanding of the neural mechanisms that underlie AOS, and speech production generally. PMID:25404911

  17. Neuroimaging Studies of Speech: An Overview of Techniques and Methodological Approaches.

    ERIC Educational Resources Information Center

    Fiez, Julie A.

    2001-01-01

    Discussion of how functional neuroimaging has been applied to the study of speech production first reviews neuroimaging methods and limitations, then describes two approaches to study of the relevant speech areas: comparison across different language production tasks and comparison of effects of different stimuli within a single task. Examples…

  18. Functional neuroimaging in obesity and the potential for development of novel treatments.

    PubMed

    Schlögl, Haiko; Horstmann, Annette; Villringer, Arno; Stumvoll, Michael

    2016-08-01

    Recently, exciting progress has been made in understanding the role of the CNS in controlling eating behaviour and in the development of overeating. Regions and networks of the human brain involved in eating behaviour and appetite control have been identified with neuroimaging techniques such as functional MRI, PET, electroencephalography, and magnetoencephalography. Hormones that regulate our drive to eat (eg, leptin, insulin, and glucagon-like peptide-1) can affect brain function. Defects in central hunger signalling are present in many pathologies. On the basis of an understanding of brain mechanisms that lead to overeating, powerful neuroimaging protocols could be a future clinical approach to allow individually tailored treatment options for patients with obesity. The aim of our Review is to provide an overview of neuroimaging approaches for obesity (ie, neuroimaging study design, questions which can be answered by neuroimaging, and limitations of neuroimaging techniques), examine current models of central nervous processes regulating eating behaviour, summarise and review important neuroimaging studies investigating therapeutic approaches to treat obesity or to control eating behaviour, and to provide a perspective on how neuroimaging might lead to new therapeutic approaches to obesity. PMID:26838265

  19. Three-dimensional electrical structure of the crust and upper mantle in Ordos Block and adjacent area: Evidence of regional lithospheric modification

    NASA Astrophysics Data System (ADS)

    Dong, Hao; Wei, Wenbo; Ye, Gaofeng; Jin, Sheng; Jones, Alan G.; Jing, Jianen; Zhang, Letian; Xie, Chengliang; Zhang, Fan; Wang, Hui

    2014-06-01

    magnetotelluric (MT) data from project SINOPROBE were acquired and modeled, using three-dimensional (3D) MT inversion, to study the electrical structure of Ordos Block, a component of the North China Craton. For the first time, a high-resolution 3D resistivity model of the lithosphere is defined for the region. Contrary to what would be expected for a stable cratonic block, a prominent lithospheric conductive complex is revealed extending from the upper mantle to the mid-to-lower crust beneath the northern part of Ordos. Correlating well with results of seismic studies, the evidence from our independent magnetotelluric data supports regional modification of the lithosphere under the north Ordos and lithosphere thinning beneath Hetao Graben. The abnormally conductive structure may result from upwelling of mantle material in mid-to-late Mesozoic beneath the northern margin of the Ordos block.

  20. Electric fields associated with small-scale magnetic holes in the plasma sheet: Evidence for electron currents

    NASA Astrophysics Data System (ADS)

    Goodrich, Katherine A.; Ergun, Robert E.; Stawarz, Julia E.

    2016-06-01

    We report observations of magnetic holes (MHs) in the near-Earth (8 RE to 12 RE) plasma sheet that have physical sizes perpendicular to the magnetic field (B) on the order of the ion Larmor radius (ρi) and, more importantly, have current layers less than ρi in thickness. Small-scale MHs can have >90% depletion in |B| and are commonly associated with the braking of bursty bulk flow events. The generation of MHs is often attributed to magnetohydrodynamic (MHD) instabilities, which requires a size greater than ρi; the depletion in |B| is from an ion current consistent with a pressure gradient. Electric field (E) observations indicate a negative potential inside of small-scale MHs that creates an outward E at the boundary, which drives an E × B electron current in a thin layer. These observations indicate that a Hall electron current is primarily responsible for the depletion of |B| in small-scale magnetic holes, rather than the ion pressure gradient.

  1. Plant-soil interactions in salt marsh environments: Experimental evidence from electrical resistivity tomography in the Venice Lagoon

    NASA Astrophysics Data System (ADS)

    Boaga, Jacopo; D'Alpaos, Andrea; Cassiani, Giorgio; Marani, Marco; Putti, Mario

    2014-09-01

    The role of root water uptake in regulating soil water saturation in salt marshes is controversial. Modeling studies suggest that soil aeration is improved by transpiration, with implications for the distribution of vegetation species and of the associated topographic features controlling the hydraulic regime of the marshland and eventually its survival. Marsh vegetation plays a key role in the preservation of such critical environment, which represents unique marker for climatic change and impact studies. However, the direct quantification of space-time aeration patterns has remained elusive, in part, because of the limitations posed by high salinity to conventional observation techniques such as time or frequency domain reflectometry. Here we show that time-lapse microscale electrical resistivity tomography, coupled with tensiometric observations, allows the identification of variably saturated zones and the characterization of space-time soil moisture dynamics in a salt marsh in the Venice Lagoon (Italy). This is the first quantitative observational experiment which confirms that periodically flooded plants are capable of producing a persistently aerated layer below the flooded surface when transpiration proceeds at a sufficiently high rate. The experimental results are compared against previously published model predictions.

  2. Principles of electrical stimulation and dorsal column mapping as it relates to spinal cord stimulation: an overview.

    PubMed

    Ramasubbu, Chitra; Flagg, Artemus; Williams, Kayode

    2013-02-01

    The last 30 years have witnessed the growth of spinal cord stimulation as a treatment modality for an increasing number of chronic pain conditions. In spite of this growth, one of the greatest criticisms is the lack of concrete evidence for the mechanism of action. With the ever increasing enlightenment with regards to the neurophysiology of pain, and the development of more dynamic neuroimaging techniques, the opportunity to better define the mechanism of action of the spinal cord stimulator will continue to expand. In the interim, clinicians will benefit from the consolidation of the available knowledge that will enhance the effective use of the device. This review serves to provide an overview of the key principles of electrical stimulation and dorsal column mapping as it relates to spinal cord stimulation. We aim at enhancing the understanding regarding the basis for successful placement of leads and manipulation of electrical parameters. PMID:23299905

  3. Evidence for unconformities in the Cenozoic of the central and south Texas Continental Shelf from regional electric log and seismic cross sections

    SciTech Connect

    Blood, T.; LaPointe, A.E.; Cran, C.E.; Stanczyk, M.F. )

    1990-09-01

    Regional stratigraphic studies conducted by the Minerals Management Service, Gulf of Mexico, Outer Continental Shelf Region, on the offshore Texas shelf have identified at least eight major and several minor unconformities within the Cenozoic sediments. The identified erosional features associated with these unconformities include structural truncation, valley incision, and submarine canyon formation, which are the characteristics of a Type I unconformity as defined by Vail. There is also evidence for onlap by the overlying beds. The major unconformities are observed on the upthrown and downthrown sides of regional growth fault systems that are roughly parallel to the Texas coast. Where data quality permits, the major unconformities are identified over most of the Texas shelf. The minor unconformities are observed in the expanded sections on the downthrown blocks of major growth faults only. Although these erosional surfaces may also be Type I unconformities, no evidence of erosion is observed on the upthrown sides of the major growth faults. The unconformities of Oligocene and lower and middle Miocene age were initially interpreted from electric log correlations and subsequently verified on seismic data. The upper Miocene and younger unconformities were first recognized through seismic stratigraphy studies and then tied to electric log correlations. Most of the unconformities are observed near partially eroded diapiric ridges located along what was the outer shelf/upper slope area at the time of the erosion. A major upper Miocene unconformity is observed in the inner shelf/transitional environment of deposition in Matagorda and Mustang Island areas. This erosional surface was most likely formed by wave erosion during the subsequent transgression after deposition of the Discorbis 12 age sediments.

  4. The Status of the Quality Control in Acupuncture-Neuroimaging Studies

    PubMed Central

    Qiu, Ke; Jing, Miaomiao; Liu, Xiaoyan; Gao, Feifei; Liang, Fanrong; Zeng, Fang

    2016-01-01

    Using neuroimaging techniques to explore the central mechanism of acupuncture gains increasing attention, but the quality control of acupuncture-neuroimaging study remains to be improved. We searched the PubMed Database during 1995 to 2014. The original English articles with neuroimaging scan performed on human beings were included. The data involved quality control including the author, sample size, characteristics of the participant, neuroimaging technology, and acupuncture intervention were extracted and analyzed. The rigorous inclusion and exclusion criteria are important guaranty for the participants' homogeneity. The standard operation process of acupuncture and the stricter requirement for acupuncturist play significant role in quality control. More attention should be paid to the quality control in future studies to improve the reproducibility and reliability of the acupuncture-neuroimaging studies. PMID:27242911

  5. Neuroimaging and the school-based assessment of traumatic brain injury.

    PubMed

    Jantz, Paul B; Bigler, Erin D

    2014-01-01

    Advanced neuroimaging contributes to a greater understanding of brain pathology following a traumatic brain injury (TBI) and has the ability to guide neurorehabilitation decisions. When integrated with the school-based psychoeducational assessment of a child with a TBI, neuroimaging can provide a different perspective when interpreting educational and behavioral variables relevant to school-based neurorehabilitation. School psychologists conducting traditional psychoeducational assessments of children with TBI seldom obtain and integrate neuroimaging, despite its availability. This article presents contextual information on the medical assessment of TBI, major types of neuroimaging, and networks of the brain. A case study illustrates the value of incorporating neuroimaging into the standard school-based psychoeducational evaluations of children with traumatic brain injury. PMID:24473251

  6. The Utility of Neuroimaging Studies for Informing Educational Practice and Policy in Reading Disorders

    PubMed Central

    Black, Jessica M.; Myers, Chelsea A.; Hoeft, Fumiko

    2015-01-01

    Educational neuroscience is an emerging scientific field that brings together researchers from neuroscience, psychology, and education to explore the neurocognitive processes underlying educational practice and theory. In this brief article, we take reading disorder (RD, also known as developmental dyslexia) as an example, and explore trends in neuroimaging research, which may have future implications for educational practice and policy. Specifically, we present two examples that have been central to research efforts in our laboratory: (a) utilizing multimodal neuroimaging to optimize criteria to diagnose RD, and (b) identifying neuroimaging markers that predict future academic outcomes. Such research is faced with important challenges, and rigorous validation is necessary before any claims of the widespread practical utility of neuroimaging can be made. Nevertheless, we contend that neuroimaging studies offer opportunities for providing critical information that could lead to advancing theory of reading and RD. This could in turn lead to better diagnostic criteria and more accurate and earlier identification of RD. PMID:25732015

  7. Seeing responsibility: can neuroimaging teach us anything about moral and legal responsibility?

    PubMed

    Wasserman, David; Johnston, Josephine

    2014-01-01

    As imaging technologies help us understand the structure and function of the brain, providing insight into human capabilities as basic as vision and as complex as memory, and human conditions as impairing as depression and as fraught as psychopathy, some have asked whether they can also help us understand human agency. Specifically, could neuroimaging lead us to reassess the socially significant practice of assigning and taking responsibility? While responsibility itself is not a psychological process open to investigation through neuroimaging, decision-making is. Over the past decade, different researchers and scholars have sought to use neuroimaging (or the results of neuroimaging studies) to investigate what is going on in the brain when we make decisions. The results of this research raise the question whether neuroscience-especially now that it includes neuroimaging-can and should alter our understandings of responsibility and our related practice of holding people responsible. It is this question that we investigate here. PMID:24634084

  8. Predicting the Naturalistic Course of Major Depressive Disorder Using Clinical and Multimodal Neuroimaging Information: A Multivariate Pattern Recognition Study

    PubMed Central

    Schmaal, Lianne; Marquand, Andre F.; Rhebergen, Didi; van Tol, Marie-José; Ruhé, Henricus G.; van der Wee, Nic J.A.; Veltman, Dick J.; Penninx, Brenda W.J.H.

    2015-01-01

    Background A chronic course of major depressive disorder (MDD) is associated with profound alterations in brain volumes and emotional and cognitive processing. However, no neurobiological markers have been identified that prospectively predict MDD course trajectories. This study evaluated the prognostic value of different neuroimaging modalities, clinical characteristics, and their combination to classify MDD course trajectories. Methods One hundred eighteen MDD patients underwent structural and functional magnetic resonance imaging (MRI) (emotional facial expressions and executive functioning) and were clinically followed-up at 2 years. Three MDD trajectories (chronic n = 23, gradual improving n = 36, and fast remission n = 59) were identified based on Life Chart Interview measuring the presence of symptoms each month. Gaussian process classifiers were employed to evaluate prognostic value of neuroimaging data and clinical characteristics (including baseline severity, duration, and comorbidity). Results Chronic patients could be discriminated from patients with more favorable trajectories from neural responses to various emotional faces (up to 73% accuracy) but not from structural MRI and functional MRI related to executive functioning. Chronic patients could also be discriminated from remitted patients based on clinical characteristics (accuracy 69%) but not when age differences between the groups were taken into account. Combining different task contrasts or data sources increased prediction accuracies in some but not all cases. Conclusions Our findings provide evidence that the prediction of naturalistic course of depression over 2 years is improved by considering neuroimaging data especially derived from neural responses to emotional facial expressions. Neural responses to emotional salient faces more accurately predicted outcome than clinical data. PMID:25702259

  9. A Comparison of Neuroimaging Findings in Childhood Onset Schizophrenia and Autism Spectrum Disorder: A Review of the Literature

    PubMed Central

    Baribeau, Danielle A.; Anagnostou, Evdokia

    2013-01-01

    Background: Autism spectrum disorder (ASD) and childhood onset schizophrenia (COS) are pediatric neurodevelopmental disorders associated with significant morbidity. Both conditions are thought to share an underlying genetic architecture. A comparison of neuroimaging findings across ASD and COS with a focus on altered neurodevelopmental trajectories can shed light on potential clinical biomarkers and may highlight an underlying etiopathogenesis. Methods: A comprehensive review of the medical literature was conducted to summarize neuroimaging data with respect to both conditions in terms of structural imaging (including volumetric analysis, cortical thickness and morphology, and region of interest studies), white matter analysis (include volumetric analysis and diffusion tensor imaging) and functional connectivity. Results: In ASD, a pattern of early brain overgrowth in the first few years of life is followed by dysmaturation in adolescence. Functional analyses have suggested impaired long-range connectivity as well as increased local and/or subcortical connectivity in this condition. In COS, deficits in cerebral volume, cortical thickness, and white matter maturation seem most pronounced in childhood and adolescence, and may level off in adulthood. Deficits in local connectivity, with increased long-range connectivity have been proposed, in keeping with exaggerated cortical thinning. Conclusion: The neuroimaging literature supports a neurodevelopmental origin of both ASD and COS and provides evidence for dynamic changes in both conditions that vary across space and time in the developing brain. Looking forward, imaging studies which capture the early post natal period, which are longitudinal and prospective, and which maximize the signal to noise ratio across heterogeneous conditions will be required to translate research findings into a clinical environment. PMID:24391605

  10. Neural convergence and divergence in the mammalian cerebral cortex: from experimental neuroanatomy to functional neuroimaging

    PubMed Central

    Man, Kingson; Kaplan, Jonas; Damasio, Hanna; Damasio, Antonio

    2013-01-01

    A development essential for understanding the neural basis of complex behavior and cognition is the description, during the last quarter of the twentieth century, of detailed patterns of neuronal circuitry in the mammalian cerebral cortex. This effort established that sensory pathways exhibit successive levels of convergence, from the early sensory cortices to sensory-specific association cortices and to multisensory association cortices, culminating in maximally integrative regions; and that this convergence is reciprocated by successive levels of divergence, from the maximally integrative areas all the way back to the early sensory cortices. This article first provides a brief historical review of these neuroanatomical findings, which were relevant to the study of brain and mind-behavior relationships using a variety of approaches and to the proposal of heuristic anatomo-functional frameworks. In a second part, the article reviews new evidence that has accumulated from studies of functional neuroimaging, employing both univariate and multivariate analyses, as well as electrophysiology, in humans and other mammals, that the integration of information across the auditory, visual, and somatosensory-motor modalities proceeds in a content-rich manner. Behaviorally and cognitively relevant information is extracted from and conserved across the different modalities, both in higher-order association cortices and in early sensory cortices. Such stimulus-specific information is plausibly relayed along the neuroanatomical pathways alluded to above. The evidence reviewed here suggests the need for further in-depth exploration of the intricate connectivity of the mammalian cerebral cortex in experimental neuroanatomical studies. PMID:23840023

  11. Experimental evidence for an optical interference model for vibrational sum frequency generation on multilayer organic thin film systems. I. Electric dipole approximation

    SciTech Connect

    O’Brien, Daniel B.; Massari, Aaron M.

    2015-01-14

    In the field of vibrational sum frequency generation spectroscopy (VSFG) applied to organic thin film systems, a significant challenge to data analysis is in the accurate description of optical interference effects. Herein, we provide experimental evidence that a model recently developed in our lab provides an accurate description of this phenomenon. We studied the organic small molecule N,N′-dioctyl-3,4,9,10-perylenedicarboximide vapor deposited as a thickness gradient on silicon wafer substrates with two oxide thicknesses and two surface preps. VSFG data were obtained using the ssp and the sps polarization combinations in the imide carbonyl stretching region as a function of organic thickness. In this first of two reports, the data are modeled and interpreted within the ubiquitous electric dipole approximation for VSFG. The intrinsic sample responses are parameterized during the fitting routines while optical interference effects are simply calculated from the model using known refractive indices, thin film thicknesses, and beam angles. The results indicate that the thin film model provides a good description of optical interferences, indicating that interfacial terms are significant. Inconsistencies between the fitting results within the bounds of the electric dipole response motivate deliberation for additional effects to be considered in the second report.

  12. Bifurcation in the Steady-State Height of Colloidal Particles near an Electrode in Oscillatory Electric Fields: Evidence for a Tertiary Potential Minimum

    NASA Astrophysics Data System (ADS)

    Woehl, T. J.; Chen, B. J.; Heatley, K. L.; Talken, N. H.; Bukosky, S. C.; Dutcher, C. S.; Ristenpart, W. D.

    2015-01-01

    Application of an oscillatory electric field is known to alter the separation distance between micron-scale colloidal particles and an adjacent electrode. This behavior is believed to be partially due to a lift force caused by electrohydrodynamic flow generated around each particle, with previous work focused on identifying a single steady-state "height" of the individual particles over the electrode. Here, we report the existence of a pronounced bifurcation in the particle height in response to low-frequency electric fields. Optical and confocal microscopy observations reveal that application of a ˜100 Hz field induces some of the particles to rapidly move several particle diameters up from the electrode, while the others move closer to the electrode. Statistics compiled from repeated trials demonstrate that the likelihood for a particle to move up follows a binomial distribution, indicating that the height bifurcation is random and does not result from membership in some distinct subpopulation of particles. The fraction of particles that move up increases with increased applied potential and decreased frequency, in a fashion qualitatively consistent with an energy landscape predicated on competition between electrohydrodynamic flow, colloidal interactions, and gravitational forces. Taken together, the results provide evidence for the existence of a deep tertiary minimum in the effective electrode-particle interaction potential at a surprisingly large distance from the electrode.

  13. Experimental evidence for an optical interference model for vibrational sum frequency generation on multilayer organic thin film systems. I. Electric dipole approximation

    NASA Astrophysics Data System (ADS)

    O'Brien, Daniel B.; Massari, Aaron M.

    2015-01-01

    In the field of vibrational sum frequency generation spectroscopy (VSFG) applied to organic thin film systems, a significant challenge to data analysis is in the accurate description of optical interference effects. Herein, we provide experimental evidence that a model recently developed in our lab provides an accurate description of this phenomenon. We studied the organic small molecule N,N'-dioctyl-3,4,9,10-perylenedicarboximide vapor deposited as a thickness gradient on silicon wafer substrates with two oxide thicknesses and two surface preps. VSFG data were obtained using the ssp and the sps polarization combinations in the imide carbonyl stretching region as a function of organic thickness. In this first of two reports, the data are modeled and interpreted within the ubiquitous electric dipole approximation for VSFG. The intrinsic sample responses are parameterized during the fitting routines while optical interference effects are simply calculated from the model using known refractive indices, thin film thicknesses, and beam angles. The results indicate that the thin film model provides a good description of optical interferences, indicating that interfacial terms are significant. Inconsistencies between the fitting results within the bounds of the electric dipole response motivate deliberation for additional effects to be considered in the second report.

  14. Sleep modulates cortical connectivity and excitability in humans: Direct evidence from neural activity induced by single-pulse electrical stimulation.

    PubMed

    Usami, Kiyohide; Matsumoto, Riki; Kobayashi, Katsuya; Hitomi, Takefumi; Shimotake, Akihiro; Kikuchi, Takayuki; Matsuhashi, Masao; Kunieda, Takeharu; Mikuni, Nobuhiro; Miyamoto, Susumu; Fukuyama, Hidenao; Takahashi, Ryosuke; Ikeda, Akio

    2015-11-01

    Sleep-induced changes in human brain connectivity/excitability and their physiologic basis remain unclear, especially in the frontal lobe. We investigated sleep-induced connectivity and excitability changes in 11 patients who underwent chronic implantation of subdural electrodes for epilepsy surgery. Single-pulse electrical stimuli were directly injected to a part of the cortices, and cortico-cortical evoked potentials (CCEPs) and CCEP-related high-gamma activities (HGA: 100-200 Hz) were recorded from adjacent and remote cortices as proxies of effective connectivity and induced neuronal activity, respectively. HGA power during the initial CCEP component (N1) correlated with the N1 size itself across all states investigated. The degree of cortical connectivity and excitability changed during sleep depending on sleep stage, approximately showing dichotomy of awake vs. non-rapid eye movement (REM) [NREM] sleep. On the other hand, REM sleep partly had properties of both awake and NREM sleep, placing itself in the intermediate state between them. Compared with the awake state, single-pulse stimulation especially during NREM sleep induced increased connectivity (N1 size) and neuronal excitability (HGA increase at N1), which was immediately followed by intense inhibition (HGA decrease). The HGA decrease was temporally followed by the N2 peak (the second CCEP component), and then by HGA re-increase during sleep across all lobes. This HGA rebound or re-increase of neuronal synchrony was largest in the frontal lobe compared with the other lobes. These properties of sleep-induced changes of the cortex may be related to unconsciousness during sleep and frequent nocturnal seizures in frontal lobe epilepsy. PMID:26309062

  15. Towards structured sharing of raw and derived neuroimaging data across existing resources.

    PubMed

    Keator, D B; Helmer, K; Steffener, J; Turner, J A; Van Erp, T G M; Gadde, S; Ashish, N; Burns, G A; Nichols, B N

    2013-11-15

    Data sharing efforts increasingly contribute to the acceleration of scientific discovery. Neuroimaging data is accumulating in distributed domain-specific databases and there is currently no integrated access mechanism nor an accepted format for the critically important meta-data that is necessary for making use of the combined, available neuroimaging data. In this manuscript, we present work from the Derived Data Working Group, an open-access group sponsored by the Biomedical Informatics Research Network (BIRN) and the International Neuroimaging Coordinating Facility (INCF) focused on practical tools for distributed access to neuroimaging data. The working group develops models and tools facilitating the structured interchange of neuroimaging meta-data and is making progress towards a unified set of tools for such data and meta-data exchange. We report on the key components required for integrated access to raw and derived neuroimaging data as well as associated meta-data and provenance across neuroimaging resources. The components include (1) a structured terminology that provides semantic context to data, (2) a formal data model for neuroimaging with robust tracking of data provenance, (3) a web service-based application programming interface (API) that provides a consistent mechanism to access and query the data model, and (4) a provenance library that can be used for the extraction of provenance data by image analysts and imaging software developers. We believe that the framework and set of tools outlined in this manuscript have great potential for solving many of the issues the neuroimaging community faces when sharing raw and derived neuroimaging data across the various existing database systems for the purpose of accelerating scientific discovery. PMID:23727024

  16. Towards structured sharing of raw and derived neuroimaging data across existing resources

    PubMed Central

    Keator, D.B.; Helmer, K.; Steffener, J.; Turner, J.A.; Van Erp, T.G.M.; Gadde, S.; Ashish, N.; Burns, G.A.; Nichols, B.N.

    2013-01-01

    Data sharing efforts increasingly contribute to the acceleration of scientific discovery. Neuroimaging data is accumulating in distributed domain-specific databases and there is currently no integrated access mechanism nor an accepted format for the critically important meta-data that is necessary for making use of the combined, available neuroimaging data. In this manuscript, we present work from the Derived Data Working Group, an open-access group sponsored by the Biomedical Informatics Research Network (BIRN) and the International Neuroimaging Coordinating Facility (INCF) focused on practical tools for distributed access to neuroimaging data. The working group develops models and tools facilitating the structured interchange of neuroimaging meta-data and is making progress towards a unified set of tools for such data and meta-data exchange. We report on the key components required for integrated access to raw and derived neuroimaging data as well as associated meta-data and provenance across neuroimaging resources. The components include (1) a structured terminology that provides semantic context to data, (2) a formal data model for neuroimaging with robust tracking of data provenance, (3) a web service-based application programming interface (API) that provides a consistent mechanism to access and query the data model, and (4) a provenance library that can be used for the extraction of provenance data by image analysts and imaging software developers. We believe that the framework and set of tools outlined in this manuscript have great potential for solving many of the issues the neuroimaging community faces when sharing raw and derived neuroimaging data across the various existing database systems for the purpose of accelerating scientific discovery. PMID:23727024

  17. Insights from neuroenergetics into the interpretation of functional neuroimaging: an alternative empirical model for studying the brain's support of behavior

    PubMed Central

    Shulman, Robert G; Hyder, Fahmeed; Rothman, Douglas L

    2014-01-01

    Functional neuroimaging measures quantitative changes in neurophysiological parameters coupled to neuronal activity during observable behavior. These results have usually been interpreted by assuming that mental causation of behavior arises from the simultaneous actions of distinct psychological mechanisms or modules. However, reproducible localization of these modules in the brain using functional magnetic resonance imaging (MRI) and positron emission tomography (PET) imaging has been elusive other than for sensory systems. In this paper, we show that neuroenergetic studies using PET, calibrated functional magnetic resonance imaging (fMRI), 13C magnetic resonance spectroscopy, and electrical recordings do not support the standard approach, which identifies the location of mental modules from changes in brain activity. Of importance in reaching this conclusion is that changes in neuronal activities underlying the fMRI signal are many times smaller than the high ubiquitous, baseline neuronal activity, or energy in resting, awake humans. Furthermore, the incremental signal depends on the baseline activity contradicting theoretical assumptions about linearity and insertion of mental modules. To avoid these problems, while making use of these valuable results, we propose that neuroimaging should be used to identify observable brain activities that are necessary for a person's observable behavior rather than being used to seek hypothesized mental processes. PMID:25160670

  18. Neoplastic cauda equina syndrome: a neuroimaging-based review.

    PubMed

    Bennett, Shelby J; Katzman, Gregory L; Roos, Raymond P; Mehta, Amar S; Ali, Saad

    2016-02-01

    Cauda equina syndrome refers to dysfunction of the cauda equina, the collection of ventral and dorsal lumbar, sacral and coccygeal nerve roots that surround the filum terminale. This most commonly occurs as a result of compression by a herniated lumbosacral disc. However, the syndrome may also complicate metastatic cancer or a primary neoplasm within or infiltrating the spinal canal. An accurate and timely diagnosis is critical to avoid irreversible loss of neurological function. The clinician and radiologist must therefore be aware of the many possible causes to guide timely management. Here we review the diverse neoplastic causes affecting the cauda equina nerve roots from a neuroimaging-based perspective. We divide them by location into intramedullary neoplasms at the conus (such as astrocytoma), intradural-extramedullary neoplasms (such as schwannoma and leptomeningeal metastases) and extradural neoplasms (such as spinal metastases from systemic neoplasms). We also discuss the clinical features associated with cauda equina tumours, with special focus on cauda equina syndrome. PMID:26442520

  19. Neuroimaging studies of striatum in cognition part II: Parkinson's disease

    PubMed Central

    Hanganu, Alexandru; Provost, Jean-Sebastien; Monchi, Oury

    2015-01-01

    In recent years a gradual shift in the definition of Parkinson's disease (PD) has been established, from a classical akinetic-rigid movement disorder to a multi-system neurodegenerative disease. While the pathophysiology of PD is complex and goes much beyond the nigro-striatal degeneration, the striatum has been shown to be responsible for many cognitive functions. Patients with PD develop impairments in multiple cognitive domains and the PD model is probably the most extensively studied regarding striatum dysfunction and its influence on cognition. Up to 40% of PD patients present cognitive impairment even in the early stages of disease development. Thus, understanding the key patterns of striatum and connecting regions' influence on cognition will help develop more specific approaches to alleviate cognitive impairment and slow down its decline. This review focuses on the contribution of neuroimaging studies in understanding how striatum impairment affects cognition in PD. PMID:26500512

  20. Neuroimaging biomarkers for Parkinson disease: facts and fantasy.

    PubMed

    Perlmutter, Joel S; Norris, Scott A

    2014-12-01

    In this grand rounds, we focus on development, validation, and application of neuroimaging biomarkers for Parkinson disease (PD). We cover whether such biomarkers can be used to identify presymptomatic individuals (probably yes), provide a measure of PD severity (in a limited fashion, but frequently done poorly), investigate pathophysiology of parkinsonian disorders (yes, if done carefully), play a role in differential diagnosis of parkinsonism (not well), and investigate pathology underlying cognitive impairment (yes, in conjunction with postmortem data). Along the way, we clarify several issues about definitions of biomarkers and surrogate endpoints. The goal of this lecture is to provide a basis for interpreting current literature and newly proposed clinical tools in PD. In the end, one should be able to critically distinguish fact from fantasy. PMID:25363872

  1. Preclinical PET Neuroimaging of [11C]Bexarotene.

    PubMed

    Rotstein, Benjamin H; Placzek, Michael S; Krishnan, Hema S; Pekošak, Aleksandra; Collier, Thomas Lee; Wang, Changning; Liang, Steven H; Burstein, Ethan S; Hooker, Jacob M; Vasdev, Neil

    2016-01-01

    Activation of retinoid X receptors (RXRs) has been proposed as a therapeutic mechanism for the treatment of neurodegeneration, including Alzheimer's and Parkinson's diseases. We previously reported radiolabeling of a Food and Drug Administration-approved RXR agonist, bexarotene, by copper-mediated [(11)C]CO2 fixation and preliminary positron emission tomography (PET) neuroimaging that demonstrated brain permeability in nonhuman primate with regional binding distribution consistent with RXRs. In this study, the brain uptake and saturability of [(11)C]bexarotene were studied in rats and nonhuman primates by PET imaging under baseline and greater target occupancy conditions. [(11)C]Bexarotene displays a high proportion of nonsaturable uptake in the brain and is unsuitable for RXR occupancy measurements in the central nervous system. PMID:27553293

  2. A review of neuroimaging biomarkers of Alzheimer’s disease

    PubMed Central

    Varghese, Tinu; Sheelakumari, R; James, Jija S; Mathuranath, PS

    2014-01-01

    Neuroimaging biomarkers have potential role in the early diagnosis as well as periodic follow-up of neurodegenerative diseases such as Alzheimer’s disease (AD). Structural imaging biomarkers can be used to predict those who are at risk or in preclinical stages of AD. It could possibly be useful even in predicting the conversion of Mild Cognitive Impairment (MCI) an early stage of AD to AD. In addition there has been a lot of progress in molecular imaging in AD. This article presents a review of recent progress in selected imaging biomarkers for early diagnosis, classification, and progression, of AD. A comprehensive integrative strategy initiated early in the cognitive decline is perhaps the most effective method of controlling progression to Alzheimer’s disease. PMID:25431627

  3. The Worldwide Alzheimer's Disease Neuroimaging Initiative: An update.

    PubMed

    Hendrix, James A; Finger, Brad; Weiner, Michael W; Frisoni, Giovanni B; Iwatsubo, Takeshi; Rowe, Christopher C; Kim, Seong Yoon; Guinjoan, Salvador M; Sevlever, Gustavo; Carrillo, Maria C

    2015-07-01

    The Alzheimer's Disease Neuroimaging Initiative (ADNI), launched in 2004, has worked to accelerate drug development by validating imaging and blood/cerebrospinal fluid biomarkers for Alzheimer's disease clinical treatment trials. ADNI is a naturalistic (nontreatment) multisite longitudinal study. A true public-private partnership, the initiative has set a new standard for data sharing without embargo and for the use of biomarkers in dementia research. The ADNI effort in North America is not the only such effort in the world. The Alzheimer's Association recognized these global efforts and formed Worldwide ADNI (WW-ADNI). By creating a platform for international collaboration and cooperation, WW-ADNI's goals are to harmonize projects and results across geographical regions and to facilitate data management and availability to investigators around the world. WW-ADNI projects include those based in North America, Europe, Japan, Australia, Korea, and Argentina. PMID:26194318

  4. Motivating forces of human actions. Neuroimaging reward and social interaction.

    PubMed

    Walter, Henrik; Abler, Birgit; Ciaramidaro, Angela; Erk, Susanne

    2005-11-15

    In neuroeconomics, reward and social interaction are central concepts to understand what motivates human behaviour. Both concepts are investigated in humans using neuroimaging methods. In this paper, we provide an overview about these results and discuss their relevance for economic behaviour. For reward it has been shown that a system exists in humans that is involved in predicting rewards and thus guides behaviour, involving a circuit including the striatum, the orbitofrontal cortex and the amygdala. Recent studies on social interaction revealed a mentalizing system representing the mental states of others. A central part of this system is the medial prefrontal cortex, in particular the anterior paracingulate cortex. The reward as well as the mentalizing system is engaged in economic decision-making. We will discuss implications of this study for neuromarketing as well as general implications of these results that may help to provide deeper insights into the motivating forces of human behaviour. PMID:16216683

  5. Antidepressant-related sexual dysfunction - perspectives from neuroimaging.

    PubMed

    Graf, Heiko; Walter, Martin; Metzger, Coraline D; Abler, Birgit

    2014-06-01

    Sexual dysfunction is not only a common symptom in major depression but also a frequent side-effect of antidepressant medication, mainly of the selective serotonin reuptake-inhibitors (SSRI) that are often prescribed as a first line treatment option. Despite of the increasing incidence and prescription rates, neuronal mechanisms underlying SSRI-related sexual dysfunction are poorly understood and investigations on this topic are scarce. Neuroimaging techniques, mainly functional magnetic resonance imaging (fMRI), provide a feasible approach to investigate these mechanisms since SSRI-related sexual dysfunction is most likely related to central nervous processes. This review summarizes the recent literature regarding the basic clinical findings and imaging correlates of antidepressant-related sexual dysfunction linking brain regions and networks potentially involved to phases and subcomponents of sexual processing and antidepressant action. In particular, fMRI studies on SSRI antidepressants including paroxetine and SNRIs including bupropion are highlighted. PMID:24333547

  6. Atlas generated generalized ROIs for use in functional neuroimaging

    SciTech Connect

    Thurfjell, L. . Dept. of Neuroradiology and Clinical Neurophysiology); Bohm, C. . Dept. of Physics)

    1994-08-01

    The interpretation of functional neuroimaging data can, in many cases, be facilitated by comparison with simulated data corresponding to the measuring situation. A computerized brain atlas is used to provide information regarding the spatial extent of the object being imaged. This knowledge combined with information about the resolution of the imaging device expressed as point spread functions is used to calculate a simulated image of the object. The simulated image can be regarded as a generalized region of interest (ROI) containing information of the object as viewed by the specific instrument. Generalized ROIs are used to automatically determine boundaries or ordinary ROIs and to provide recovery coefficients to compensate for partial volume effects. Simulations can also be used to generate three-dimensional data sets where different activity levels have been assigned to different anatomical structures. These methods are presented in this paper and some experimental results are shown.

  7. Clinical Neuroimaging Using Arterial Spin-Labeled Perfusion MRI

    PubMed Central

    Wolf, Ronald L.; Detre, John A.

    2007-01-01

    SUMMARY The two most common methods for measuring perfusion with MRI are based on dynamic susceptibility contrast (DSC) and arterial spin labeling (ASL). Although clinical experience to date is much more extensive with DSC perfusion MRI, ASL methods offer several advantages. The primary advantages are that completely noninvasive absolute cerebral blood flow (CBF) measurements are possible with relative insensitivity to permeability, and that multiple repeated measurements can be obtained to evaluate one or more interventions or to perform perfusion-based functional MRI. ASL perfusion and perfusion-based fMRI methods have been applied in many clinical settings, including acute and chronic cerebrovascular disease, CNS neoplasms, epilepsy, aging and development, neurodegenerative disorders, and neuropsychiatric diseases. Recent technical advances have improved the sensitivity of ASL perfusion MRI, and increasing use is expected in the coming years. This review focuses on ASL perfusion MRI and applications in clinical neuroimaging. PMID:17599701

  8. Neurobehavioral, neurologic, and neuroimaging characteristics of fetal alcohol spectrum disorders.

    PubMed

    Glass, Leila; Ware, Ashley L; Mattson, Sarah N

    2014-01-01

    Alcohol consumption during pregnancy can have deleterious consequences for the fetus, including changes in central nervous system development leading to permanent neurologic alterations and cognitive and behavioral deficits. Individuals affected by prenatal alcohol exposure, including those with and without fetal alcohol syndrome, are identified under the umbrella of fetal alcohol spectrum disorders (FASD). While studies of humans and animal models confirm that even low to moderate levels of exposure can have detrimental effects, critical doses of such exposure have yet to be specified and the most clinically significant and consistent consequences occur following heavy exposure. These consequences are pervasive, devastating, and can result in long-term dysfunction. This chapter summarizes the neurobehavioral, neurologic, and neuroimaging characteristics of FASD, focusing primarily on clinical research of individuals with histories of heavy prenatal alcohol exposure, although studies of lower levels of exposure, particularly prospective, longitudinal studies, will be discussed where relevant. PMID:25307589

  9. Neuroimaging studies in schizophrenia: an overview of research from Asia.

    PubMed

    Narayanaswamy, Janardhanan C; Venkatasubramanian, Ganesan; Gangadhar, Bangalore N

    2012-10-01

    Neuroimaging studies in schizophrenia help clarify the neural substrates underlying the pathogenesis of this neuropsychiatric disorder. Contemporary brain imaging in schizophrenia is predominated by magnetic resonance imaging (MRI)-based research approaches. This review focuses on the various imaging studies from India and their relevance to the understanding of brain abnormalities in schizophrenia. The existing studies are predominantly comprised of structural MRI reports involving region-of-interest and voxel-based morphometry approaches, magnetic resonance spectroscopy and single-photon emission computed tomography/positron emission tomography (SPECT/PET) studies. Most of these studies are significant in that they have evaluated antipsychotic-naïve schizophrenia patients--a relatively difficult population to obtain in contemporary research. Findings of these studies offer robust support to the existence of significant brain abnormalities at very early stages of the disorder. In addition, theoretically relevant relationships between these brain abnormalities and developmental aberrations suggest possible neurodevelopmental basis for these brain deficits. PMID:23057977

  10. Ethical concepts and future challenges of neuroimaging: an Islamic perspective.

    PubMed

    Al-Delaimy, Wael K

    2012-09-01

    Neuroscience is advancing at a rapid pace, with new technologies and approaches that are creating ethical challenges not easily addressed by current ethical frameworks and guidelines. One fascinating technology is neuroimaging, especially functional Magnetic Resonance Imaging (fMRI). Although still in its infancy, fMRI is breaking new ground in neuroscience, potentially offering increased understanding of brain function. Different populations and faith traditions will likely have different reactions to these new technologies and the ethical challenges they bring with them. Muslims are approximately one-fifth of world population and they have a specific and highly regulated ethical and moral code, which helps them deal with scientific advances and decision making processes in an Islamically ethical manner. From this ethical perspective, in light of the relevant tenets of Islam, neuroimaging poses various challenges. The privacy of spirituality and the thought process, the requirement to put community interest before individual interest, and emphasis on conscious confession in legal situations are Islamic concepts that can pose a challenge for the use of something intrusive such as an fMRI. Muslim moral concepts such as There shall be no harm inflicted or reciprocated in Islam and Necessities overrule prohibitions are some of the criteria that might appropriately be used to guide advancing neuroscience. Neuroscientists should be particularly prudent and well prepared in implementing neuroscience advances that are breaking new scientific and ethical ground. Neuroscientists should also be prepared to assist in setting the ethical frameworks in place in advance of what might be perceived as runaway applications of technology. PMID:22865482

  11. Sensitivity of the neuroimaging techniques in ischemic stroke.

    PubMed

    Smajlović, Dzevdet; Sinanović, Osman

    2004-01-01

    The aim of this study was to investigate and compare the sensitivity and effectiveness of neuroimaging techniques in 190 patients with acute ischemic stroke. The first computed tomography (CT) scan for all patients was performed within the first 12 hours of the stroke symptoms onset. For each patient, between the third and fifth day of the hospitalization, at least one more neuroimaging procedure (CT and/or magnetic resonance imaging--MRI, and/or diffusion weighted imaging--DWI) was done. The CT scan in the first 12 hours of the stroke onset was positive in 32% of the patients; the highest number of the positive findings was in the patients with total anterior circulation infarct (52%). After 48 hours of the stroke onset second CT was positive in 85% (75/89), MRI in 93.5% (115/123), and DWI in 98.8% (79/80) patients. MRI was significantly more sensitive than CT in detection of ischemic lesion (88% vs. 72%, P=0.01), particularly in the patients with lacunar infarcts (75% vs. 50%, P=0.005). In detection of ischemic stroke 48 hours of the stroke onset the slightly higher number of strokes were detected on DWI in comparison with MRI (98.6% vs. 88.7%). According to our results, within the first 12 hours after the stroke onset, CT is reliable only for detection of considerable number of cortical ischemic strokes of the anterior cerebral circulation. After 48 hours from the stroke onset CT, MRI and DWI show high sensitivity in the detection of ischemic lesion of all clinical stroke subtypes. MRI is more sensitive in comparison with CT in detection of ischemic lesion, while DWI does not show dominance in comparison with MRI in identification of ischemic stroke after 48 hours of the symptoms onset. PMID:15628251

  12. Functional Neuroimaging Insights into the Physiology of Human Sleep

    PubMed Central

    Dang-Vu, Thien Thanh; Schabus, Manuel; Desseilles, Martin; Sterpenich, Virginie; Bonjean, Maxime; Maquet, Pierre

    2010-01-01

    Functional brain imaging has been used in humans to noninvasively investigate the neural mechanisms underlying the generation of sleep stages. On the one hand, REM sleep has been associated with the activation of the pons, thalamus, limbic areas, and temporo-occipital cortices, and the deactivation of prefrontal areas, in line with theories of REM sleep generation and dreaming properties. On the other hand, during non-REM (NREM) sleep, decreases in brain activity have been consistently found in the brainstem, thalamus, and in several cortical areas including the medial prefrontal cortex (MPFC), in agreement with a homeostatic need for brain energy recovery. Benefiting from a better temporal resolution, more recent studies have characterized the brain activations related to phasic events within specific sleep stages. In particular, they have demonstrated that NREM sleep oscillations (spindles and slow waves) are indeed associated with increases in brain activity in specific subcortical and cortical areas involved in the generation or modulation of these waves. These data highlight that, even during NREM sleep, brain activity is increased, yet regionally specific and transient. Besides refining the understanding of sleep mechanisms, functional brain imaging has also advanced the description of the functional properties of sleep. For instance, it has been shown that the sleeping brain is still able to process external information and even detect the pertinence of its content. The relationship between sleep and memory has also been refined using neuroimaging, demonstrating post-learning reactivation during sleep, as well as the reorganization of memory representation on the systems level, sometimes with long-lasting effects on subsequent memory performance. Further imaging studies should focus on clarifying the role of specific sleep patterns for the processing of external stimuli, as well as the consolidation of freshly encoded information during sleep. Citation: Dang

  13. Neural correlates of the LSD experience revealed by multimodal neuroimaging.

    PubMed

    Carhart-Harris, Robin L; Muthukumaraswamy, Suresh; Roseman, Leor; Kaelen, Mendel; Droog, Wouter; Murphy, Kevin; Tagliazucchi, Enzo; Schenberg, Eduardo E; Nest, Timothy; Orban, Csaba; Leech, Robert; Williams, Luke T; Williams, Tim M; Bolstridge, Mark; Sessa, Ben; McGonigle, John; Sereno, Martin I; Nichols, David; Hellyer, Peter J; Hobden, Peter; Evans, John; Singh, Krish D; Wise, Richard G; Curran, H Valerie; Feilding, Amanda; Nutt, David J

    2016-04-26

    Lysergic acid diethylamide (LSD) is the prototypical psychedelic drug, but its effects on the human brain have never been studied before with modern neuroimaging. Here, three complementary neuroimaging techniques: arterial spin labeling (ASL), blood oxygen level-dependent (BOLD) measures, and magnetoencephalography (MEG), implemented during resting state conditions, revealed marked changes in brain activity after LSD that correlated strongly with its characteristic psychological effects. Increased visual cortex cerebral blood flow (CBF), decreased visual cortex alpha power, and a greatly expanded primary visual cortex (V1) functional connectivity profile correlated strongly with ratings of visual hallucinations, implying that intrinsic brain activity exerts greater influence on visual processing in the psychedelic state, thereby defining its hallucinatory quality. LSD's marked effects on the visual cortex did not significantly correlate with the drug's other characteristic effects on consciousness, however. Rather, decreased connectivity between the parahippocampus and retrosplenial cortex (RSC) correlated strongly with ratings of "ego-dissolution" and "altered meaning," implying the importance of this particular circuit for the maintenance of "self" or "ego" and its processing of "meaning." Strong relationships were also found between the different imaging metrics, enabling firmer inferences to be made about their functional significance. This uniquely comprehensive examination of the LSD state represents an important advance in scientific research with psychedelic drugs at a time of growing interest in their scientific and therapeutic value. The present results contribute important new insights into the characteristic hallucinatory and consciousness-altering properties of psychedelics that inform on how they can model certain pathological states and potentially treat others. PMID:27071089

  14. Neural correlates of the LSD experience revealed by multimodal neuroimaging

    PubMed Central

    Carhart-Harris, Robin L.; Muthukumaraswamy, Suresh; Roseman, Leor; Kaelen, Mendel; Droog, Wouter; Murphy, Kevin; Tagliazucchi, Enzo; Schenberg, Eduardo E.; Nest, Timothy; Orban, Csaba; Leech, Robert; Williams, Luke T.; Williams, Tim M.; Bolstridge, Mark; Sessa, Ben; McGonigle, John; Sereno, Martin I.; Nichols, David; Hobden, Peter; Evans, John; Singh, Krish D.; Wise, Richard G.; Curran, H. Valerie; Feilding, Amanda; Nutt, David J.

    2016-01-01

    Lysergic acid diethylamide (LSD) is the prototypical psychedelic drug, but its effects on the human brain have never been studied before with modern neuroimaging. Here, three complementary neuroimaging techniques: arterial spin labeling (ASL), blood oxygen level-dependent (BOLD) measures, and magnetoencephalography (MEG), implemented during resting state conditions, revealed marked changes in brain activity after LSD that correlated strongly with its characteristic psychological effects. Increased visual cortex cerebral blood flow (CBF), decreased visual cortex alpha power, and a greatly expanded primary visual cortex (V1) functional connectivity profile correlated strongly with ratings of visual hallucinations, implying that intrinsic brain activity exerts greater influence on visual processing in the psychedelic state, thereby defining its hallucinatory quality. LSD’s marked effects on the visual cortex did not significantly correlate with the drug’s other characteristic effects on consciousness, however. Rather, decreased connectivity between the parahippocampus and retrosplenial cortex (RSC) correlated strongly with ratings of “ego-dissolution” and “altered meaning,” implying the importance of this particular circuit for the maintenance of “self” or “ego” and its processing of “meaning.” Strong relationships were also found between the different imaging metrics, enabling firmer inferences to be made about their functional significance. This uniquely comprehensive examination of the LSD state represents an important advance in scientific research with psychedelic drugs at a time of growing interest in their scientific and therapeutic value. The present results contribute important new insights into the characteristic hallucinatory and consciousness-altering properties of psychedelics that inform on how they can model certain pathological states and potentially treat others. PMID:27071089

  15. Integration of Network Topological and Connectivity Properties for Neuroimaging Classification

    PubMed Central

    Jie, Biao; Gao, Wei; Wang, Qian; Wee, Chong-Yaw

    2014-01-01

    Rapid advances in neuroimaging techniques have provided an efficient and noninvasive way for exploring the structural and functional connectivity of the human brain. Quantitative measurement of abnormality of brain connectivity in patients with neurodegenerative diseases, such as mild cognitive impairment (MCI) and Alzheimer’s disease (AD), have also been widely reported, especially at a group level. Recently, machine learning techniques have been applied to the study of AD and MCI, i.e., to identify the individuals with AD/MCI from the healthy controls (HCs). However, most existing methods focus on using only a single property of a connectivity network, although multiple network properties, such as local connectivity and global topological properties, can potentially be used. In this paper, by employing multikernel based approach, we propose a novel connectivity based framework to integrate multiple properties of connectivity network for improving the classification performance. Specifically, two different types of kernels (i.e., vector-based kernel and graph kernel) are used to quantify two different yet complementary properties of the network, i.e., local connectivity and global topological properties. Then, multikernel learning (MKL) technique is adopted to fuse these heterogeneous kernels for neuroimaging classification. We test the performance of our proposed method on two different data sets. First, we test it on the functional connectivity networks of 12 MCI and 25 HC subjects. The results show that our method achieves significant performance improvement over those using only one type of network property. Specifically, our method achieves a classification accuracy of 91.9%, which is 10.8% better than those by single network-property-based methods. Then, we test our method for gender classification on a large set of functional connectivity networks with 133 infants scanned at birth, 1 year, and 2 years, also demonstrating very promising results. PMID

  16. What can functional neuroimaging tell the experimental psychologist?

    PubMed

    Henson, Richard

    2005-02-01

    I argue here that functional neuroimaging data--which I restrict to the haemodynamic techniques of fMRI and PET--can inform psychological theorizing, provided one assumes a "systematic" function-structure mapping in the brain. In this case, imaging data simply comprise another dependent variable, along with behavioural data, that can be used to test competing theories. In particular, I distinguish two types of inference: function-to-structure deduction and structure-to-function induction. With the former inference, a qualitatively different pattern of activity over the brain under two experimental conditions implies at least one different function associated with changes in the independent variable. With the second type of inference, activity of the same brain region(s) under two conditions implies a common function, possibly not predicted a priori. I illustrate these inferences with imaging studies of recognition memory, short-term memory, and repetition priming. I then consider in greater detail what is meant by a "systematic" function-structure mapping and argue that, particularly for structure-to-function induction, this entails a one-to-one mapping between functional and structural units, although the structural unit may be a network of interacting regions and care must be taken over the appropriate level of functional/structural abstraction. Nonetheless, the assumption of a systematic function-structure mapping is a "working hypothesis" that, in common with other scientific fields, cannot be proved on independent grounds and is probably best evaluated by the success of the enterprise as a whole. I also consider statistical issues such as the definition of a qualitative difference and methodological issues such as the relationship between imaging and behavioural data. I finish by reviewing various objections to neuroimaging, including neophrenology, functionalism, and equipotentiality, and by observing some criticisms of current practice in the imaging

  17. Neuroimaging and Neuromonitoring Effects of Electro and Manual Acupuncture on the Central Nervous System: A Literature Review and Analysis

    PubMed Central

    Scheffold, Brigitte Elisabeth; Hsieh, Ching-Liang; Litscher, Gerhard

    2015-01-01

    The aim of this review is to provide an overview of the different effects of manual and electroacupuncture on the central nervous system in studies with different neuroimaging interventions. The Database PubMed was searched from 1/1/2000 to 1/6/2014 with restriction to human studies in English language. Data collection for functional magnetic resonance (fMRI) studies was restricted to the period from 1/1/2010 to 1/6/2014 due to a recently published review which included all published randomized and nonrandomized controlled clinical studies as well as observational studies with control groups, no blinding required. Only studies comparing manual or electroacupuncture with sham acupuncture were eligible. All participants were healthy adult men and women. A majority of 25 studies compared manual versus sham, a minority of 7 trials compared electro versus sham and only 1 study compared electro versus manual acupuncture. In 29 out of 33 studies verum acupuncture results were found to present either more or different modulation effects on neurological components measured by neuroimaging and neuromonitoring methods than sham acupuncture. Only four studies reported no effects of verum in comparison to sham acupuncture. Evaluation of the very heterogeneous results shows evidence that verum acupuncture elicits more modulation effects on neurological components than sham acupuncture. PMID:26339269

  18. Neuroimaging and Neuromonitoring Effects of Electro and Manual Acupuncture on the Central Nervous System: A Literature Review and Analysis.

    PubMed

    Scheffold, Brigitte Elisabeth; Hsieh, Ching-Liang; Litscher, Gerhard

    2015-01-01

    The aim of this review is to provide an overview of the different effects of manual and electroacupuncture on the central nervous system in studies with different neuroimaging interventions. The Database PubMed was searched from 1/1/2000 to 1/6/2014 with restriction to human studies in English language. Data collection for functional magnetic resonance (fMRI) studies was restricted to the period from 1/1/2010 to 1/6/2014 due to a recently published review which included all published randomized and nonrandomized controlled clinical studies as well as observational studies with control groups, no blinding required. Only studies comparing manual or electroacupuncture with sham acupuncture were eligible. All participants were healthy adult men and women. A majority of 25 studies compared manual versus sham, a minority of 7 trials compared electro versus sham and only 1 study compared electro versus manual acupuncture. In 29 out of 33 studies verum acupuncture results were found to present either more or different modulation effects on neurological components measured by neuroimaging and neuromonitoring methods than sham acupuncture. Only four studies reported no effects of verum in comparison to sham acupuncture. Evaluation of the very heterogeneous results shows evidence that verum acupuncture elicits more modulation effects on neurological components than sham acupuncture. PMID:26339269

  19. Executive and semantic processes in reappraisal of negative stimuli: insights from a meta-analysis of neuroimaging studies

    PubMed Central

    Messina, Irene; Bianco, Simone; Sambin, Marco; Viviani, Roberto

    2015-01-01

    Neuroimaging investigations have identified the neural correlates of reappraisal in executive areas. These findings have been interpreted as evidence for recruitment of controlled processes, at the expense of automatic processes when responding to emotional stimuli. However, activation of semantic areas has also been reported. The aim of the present work was to address the issue of the importance of semantic areas in emotion regulation by comparing recruitment of executive and semantic neural substrates in studies investigating different reappraisal strategies. With this aim, we reviewed neuroimaging studies on reappraisal and we classified them in two main categories: reappraisal of stimuli (RS) and reappraisal via perspective taking (RPT). We applied a coordinate-based meta-analysis to summarize the results of fMRI studies on different reappraisal strategies. Our results showed that reappraisal, when considered regardless of the specific instruction used in the studies, involved both executive and semantic areas of the brain. When considering different reappraisal strategies separately, in contrast, we found areas associated with executive function to be prominently recruited by RS, even if also semantic areas were activated. Instead, in RPT the most important clusters of brain activity were found in parietal and temporal semantic areas, without significant clusters in executive areas. These results indicate that modulation of activity in semantic areas may constitute an important aspect of emotion regulation in reappraisal, suggesting that semantic processes may be more important to understand the mechanism of emotion regulation than previously thought. PMID:26217277

  20. The importance of combining MRI and large-scale digital histology in neuroimaging studies of brain connectivity and disease

    PubMed Central

    Annese, Jacopo

    2012-01-01

    One of the major issues hindering a comprehensive connectivity model for the human brain is the difficulty in linking Magnetic Resonance Imaging (MRI) measurements to anatomical evidence produced by histological methods. In vivo and postmortem neuroimaging methodologies are still largely incompatible in terms of sample size, scale, and resolution. To help bridge the hiatus between different approaches we have established a program that characterizes the brain of individual subjects, combining MRI with postmortem neuroanatomy. The direct correlation of MRI and histological features is possible, because registered images from different modalities represent the same regions in the same brain. Comparisons are also facilitated by large-scale, digital microscopy techniques that afford images of the whole-brain sections at cellular resolution. The goal is to create a neuroimaging catalog representative of discrete age groups and specific neurological conditions. Individually, the datasets allow for investigating the relationship between different modalities; combined, they provide sufficient predictive power to inform analyses and interpretations made in the context of non-invasive studies of brain connectivity and disease. PMID:22536182

  1. The impact of the 1991 Gulf War on the mind and brain: findings from neuropsychological and neuroimaging research

    PubMed Central

    Vasterling, Jennifer J; Bremner, J. Douglas

    2006-01-01

    Many veterans of the 1991 Gulf War (GW) have complained of somatic and cognitive symptoms that may be neurological in nature. However, whether or not changes in brain function are associated with GW service continues to be debated. Studies of GW veterans using objective, performance-based neuropsychological measures have yielded inconsistent findings, with those indicating deficits among GW veterans typically revealing only relatively mild levels of neuropsychological impairment. Further, performances on objective neuropsychological tasks show little correspondence to subjective perceptions of cognitive functioning. Although preliminary magnetic resonance spectroscopy (MRS) studies demonstrate reduced N-acetylaspartate-to-creatine (NAA/Cr) ratio in select brain regions among GW veterans who report health concerns, this work requires further replication with larger, more representative samples. There is no evidence from neuroimaging studies of a non-specific effect of GW service or of changes in brain structure or function related to health status when conventional radiological methods are used. Owing to the paucity of objective exposure, baseline health data, and the now significant time elapsed since the GW, aetiological issues may never be fully resolved. Therefore, research addressing clinical management of GW veterans with neuropsychological dysfunction and neuroimaging abnormalities may prove more fruitful than exclusive focus on aetiology. PMID:16687264

  2. Non-invasive access to the vagus nerve central projections via electrical stimulation of the external ear: fMRI evidence in humans

    PubMed Central

    Frangos, Eleni; Ellrich, Jens; Komisaruk, Barry R.

    2014-01-01

    Background Tract-tracing studies in cats and rats demonstrated that the auricular branch of the vagus nerve (ABVN) projects to the nucleus tractus solitarii (NTS); it has remained unclear as to whether or not the ABVN projects to the NTS in humans. Objective To ascertain whether non-invasive electrical stimulation of the cymba conchae, a region of the external ear exclusively innervated by the ABVN, activates the NTS and the “classical” central vagal projections in humans. Methods Twelve healthy adults underwent two fMRI scans in the same session. Electrical stimulation (continuous 0.25ms pulses, 25Hz) was applied to the earlobe (control, scan #1) and left cymba conchae (scan #2). Statistical analyses were performed with FSL. Two region-of-interest analyses were performed to test the effects of cymba conchae stimulation (compared to baseline and control, earlobe, stimulation) on the central vagal projections (corrected; brainstem p<0.01, forebrain p<0.05), followed by a whole-brain analysis (corrected, p< 0.05). Results Cymba conchae stimulation, compared to earlobe (control) stimulation, produced significant activation of the “classical” central vagal projections, e.g., widespread activity in the ipsilateral nucleus of the solitary tract, bilateral spinal trigeminal nucleus, dorsal raphe, locus coeruleus, and contralateral parabrachial area, amygdala, and nucleus accumbens. Bilateral activation of the paracentral lobule was also observed. Deactivations were observed bilaterally in the hippocampus and hypothalamus. Conclusion These findings provide evidence in humans that the central projections of the ABVN are consistent with the “classical” central vagal projections and can be accessed non-invasively via the external ear. PMID:25573069

  3. The brain following transjugular intrahepatic portosystemic shunt: the perspective from neuroimaging.

    PubMed

    Chen, Hui Juan; Zheng, Gang; Wichmann, Julian L; Schoepf, U Joseph; Lu, Guang Ming; Zhang, Long Jiang

    2015-12-01

    Hepatic encephalopathy (HE) is a common complication after implantation of a transjugular intrahepatic portosystemic shunt (TIPS). Neuroimaging offers a variety of techniques for non-invasive evaluation of alterations in metabolism, as well as structural and functional changes of the brain in patients after TIPS implantation. In this article, we review the epidemiology and pathophysiology of post-TIPS HE. The potential of neuroimaging including positron emission tomography and multimodality magnetic resonance imaging to investigate the pathophysiology of post-TIPS HE is presented. We also give a perspective on the role of neuroimaging in this field. PMID:26404041

  4. [What happens in the brain of my patients? Neuroimaging and neurogenetics as ethical challenges in medicine].

    PubMed

    Synofzik, M

    2007-12-01

    Precise diagnosis of many neurological or psychiatric diseases has for long been one of the main problems in medicine. New diagnostic procedures like neuroimaging or neurogenetics seem now able to change thi situation but evoke new ethical questions. How should we cope with the fact that we may be able to diagnose and even predict diseases like schizophrenia or Alzheimer's Disease? How should we deal with incidental findings in neuroimaging? Can and should we use neuroimaging or neurogenetic procedures to detect certain behavioral dispositions? A new interdisciplinary research programme, called "neuroethics", can provide an ethical orientation for such questions. PMID:18050032

  5. Ethical issues in neuroimaging health research: an IPA study with research participants.

    PubMed

    Shaw, Rachel L; Senior, Carl; Peel, Elizabeth; Cooke, Richard; Donnelly, Louise S

    2008-11-01

    Neuroimaging is increasingly used to understand conditions like stroke and epilepsy. However, there is growing recognition that neuroimaging can raise ethical issues. We used interpretative phenomenological analysis to analyse interview data pre-and post-scan to explore these ethical issues. Findings show participants can become anxious prior to scanning and the protocol for managing incidental findings is unclear. Participants lacked a frame of reference to contextualize their expectations and often drew on medical narratives. Recommendations to reduce anxiety include dialogue between researcher and participant to clarify understanding during consent and the use of a ;virtual tour' of the neuroimaging experience. PMID:18987078

  6. Neuroimaging the short- and long-term effects of repeated picture naming in healthy older adults.

    PubMed

    MacDonald, Anna D; Heath, Shiree; McMahon, Katie L; Nickels, Lyndsey; Angwin, Anthony J; van Hees, Sophia; Johnson, Kori; Copland, David A

    2015-08-01

    Repeated attempts to name pictures can improve subsequent naming for aphasic individuals with anomia, however, the neurocognitive mechanisms responsible for such improvements are unknown. This study investigated repeated picture naming in healthy older adults over a period of minutes (short-term) after one repetition and a period of days (long-term) after multiple repetitions. Compared to unprimed pictures, both repeated conditions showed faster naming latencies with the fastest latencies evident for the short-term condition. Neuroimaging results identified repetition suppression effects across three left inferior frontal gyrus regions of interest: for both the short- and long-term conditions in the pars orbitalis, and for long-term items in the pars triangularis and pars opercularis regions. The whole brain analysis also showed a repetition suppression effect in bilateral pars triangularis regions for the long-term condition. These findings within the inferior frontal gyrus suggest that effects of repeated naming may be driven by a mapping mechanism across multiple levels of representation, possibly reflecting different levels of learning, and lend support to the idea that processing may be hierarchically organised in the left inferior frontal gyrus. The whole brain analysis also revealed repetition suppression for the long-term condition within the posterior portion of bilateral inferior temporal gyri, which may reflect attenuation of integration processes within this region following the learning of task-relevant information. PMID:26071256

  7. Behavioral and neuroimaging responses induced by mental imagery of threatening scenarios.

    PubMed

    Shuhama, Rosana; Rondinoni, Carlo; de Araujo, Draulio Barros; de Freitas Caetano, Gustavo; Dos Santos, Antonio Carlos; Graeff, Frederico Guilherme; Del-Ben, Cristina Marta

    2016-10-15

    Functional neuroimaging studies have shown that actual situations of uncertain or distant threats increase the activity of forebrain regions, whereas proximal threats increase the activity of the dorsal midbrain. This experiment aimed at testing the hypothesis that brain activity elicited by imagined scenarios of threats with two different magnitudes, potential and imminent, resembles that found in response to actual threats. First, we measured subjective responses to imagined scenarios of potential and imminent threats compared with neutral and pleasant scenarios. The same scenarios were used as a paradigm in a functional magnetic resonance imaging experiment. Behavioral results show that the scenarios draw a gradient of hedonic valence and arousal dimensions. Both potential and imminent threat scenarios increased subjective anxiety; the imminent threat scenario also increased feelings of discomfort and bodily symptoms. The functional magnetic resonance imaging results revealed modulations of BOLD signal in the ventromedial prefrontal cortex by potential threat and in the periaqueductal gray matter by imminent threat. These results agree with previously reported evidence using actual threat situations, indicating that mental imagery is a reliable method for studying the functional neuroanatomy of relevant behavioral processes. PMID:27452804

  8. Emotion and cognition interactions in PTSD: a review of neurocognitive and neuroimaging studies

    PubMed Central

    Hayes, Jasmeet P.; VanElzakker, Michael B.; Shin, Lisa M.

    2012-01-01

    Posttraumatic stress disorder (PTSD) is a psychiatric syndrome that develops after exposure to terrifying and life-threatening events including warfare, motor-vehicle accidents, and physical and sexual assault. The emotional experience of psychological trauma can have long-term cognitive effects. The hallmark symptoms of PTSD involve alterations to cognitive processes such as memory, attention, planning, and problem solving, underscoring the detrimental impact that negative emotionality has on cognitive functioning. As such, an important challenge for PTSD researchers and treatment providers is to understand the dynamic interplay between emotion and cognition. Contemporary cognitive models of PTSD theorize that a preponderance of information processing resources are allocated toward threat detection and interpretation of innocuous stimuli as threatening, narrowing one's attentional focus at the expense of other cognitive operations. Decades of research have shown support for these cognitive models of PTSD using a variety of tasks and methodological approaches. The primary goal of this review is to summarize the latest neurocognitive and neuroimaging research of emotion-cognition interactions in PTSD. To directly assess the influence of emotion on cognition and vice versa, the studies reviewed employed challenge tasks that included both cognitive and emotional components. The findings provide evidence for memory and attention deficits in PTSD that are often associated with changes in functional brain activity. The results are reviewed to provide future directions for research that may direct better and more effective treatments for PTSD. PMID:23087624

  9. Neuroimaging correlates of 22q11.2 deletion syndrome: implications for schizophrenia research.

    PubMed

    Boot, E; van Amelsvoort, T A M J

    2012-01-01

    22q11.2 Deletion syndrome (22q11DS) is the most common known recurrent copy-number variant disorder. It is also the most common known genetic risk factor for schizophrenia. The greater homogeneity of subjects with schizophrenia in 22q11DS compared with schizophrenia in the wider non-deleted population may help to identify much needed information on neuroanatomical substrates, and neurochemical and neurofunctional mechanisms that may modulate the risk for schizophrenia. Identification of the underlying pathophysiology creates opportunities for developing genotype-specific, biology-based and targeted treatments to prevent, delay or minimize the severity of schizophrenia in both 22q11DS and the wider non-deleted population. This article reviews neuroimaging studies that focused on brain structure and function in this high-risk population, with particular attention to schizophrenia research. We also discuss the evidence on the role of candidate genes within the 22q11.2 region, with particular reference to catechol-O-methyl transferase (COMT) and proline dehydrogenase (PRODH). PMID:23279171

  10. Neuroimaging of the Dopamine/Reward System in Adolescent Drug Use

    PubMed Central

    Ernst, Monique; Luciana, Monica

    2015-01-01

    Adolescence is characterized by heightened risk-taking, including substance misuse. These behavioral patterns are influenced by ontogenic changes in neurotransmitter systems, particularly the dopamine system, which is fundamentally involved in the neural coding of reward and motivated approach behavior. During adolescence, this system evidences a peak in activity. At the same time, the dopamine system is neuroplastically altered by substance abuse, impacting subsequent function. Here, we describe properties of the dopamine system that change with typical adolescent development and that are altered with substance abuse. Much of this work has been gleaned from animal models due to limitations in measuring dopamine in pediatric samples. Structural and functional neuroimaging techniques have been used to examine structures that are heavily DA-innervated; they measure morphological and functional changes with age and with drug exposure. Presenting marijuana abuse as an exemplar, we consider recent findings that support an adolescent peak in DA-driven reward-seeking behavior and related deviations in motivational systems that are associated with marijuana abuse/dependence. Clinicians are advised that (1) chronic adolescent marijuana use may lead to deficiencies in incentive motivation, (2) that this state is due to marijuana’s interactions with the developing DA system, and (3) that treatment strategies should be directed to remediating resultant deficiencies in goal-directed activity. PMID:26095977

  11. Meta-analysis of 41 Functional Neuroimaging Studies of Executive Function in Schizophrenia

    PubMed Central

    Minzenberg, Michael J.; Laird, Angela R.; Thelen, Sarah; Carter, Cameron S.; Glahn, David C.

    2010-01-01

    Context: Prefrontal cortical dysfunction is frequently reported in schizophrenia. It remains unclear whether this represents the coincidence of several prefrontal region- and process-specific impairments or a more unitary dysfunction in a superordinate cognitive control network. Whether these impairments are properly considered reflective of hypofrontality vs hyperfrontality remains unresolved. Objectives: To test whether common nodes of the cognitive control network exhibit altered activity across functional neuroimaging studies of executive cognition in schizophrenia and to evaluate the direction of these effects. Data Sources: PubMed database. Study Selection: Forty-one English-language, peer-reviewed articles published prior to February 2007 were included. All reports used functional neuroimaging during executive function performance by adult patients with schizophrenia and reported whole-brain analyses in standard stereotactic space. Tasks primarily included the delayed match-to-sample, N-back, AX-CPT, and Stroop tasks. Data Extraction: Activation likelihood estimation modeling reported activation maxima as the center of a 3-dimensional gaussian function in the meta-analysis, with statistical thresholding and correction for multiple comparisons. Data Synthesis: In within-group analyses, healthy controls and patients activated a similarly distributed cortical-subcortical network, prominently including the dorsolateral prefrontal cortex (PFC), ventrolateral PFC, anterior cingulate cortex (ACC), and thalamus. In between-group analyses, patients showed reduced activation in the left dorsolateral PFC, rostral/dorsal ACC, left thalamus (with significant co-occurrence of these areas), and inferior/ posterior cortical areas. Increased activation was observed in several midline cortical areas. Activation within groups varied modestly by task. Conclusions: Healthy adults and schizophrenic patients activate a qualitatively similar neural network during executive task

  12. Random forests on Hadoop for genome-wide association studies of multivariate neuroimaging phenotypes

    PubMed Central

    2013-01-01

    Motivation Multivariate quantitative traits arise naturally in recent neuroimaging genetics studies, in which both structural and functional variability of the human brain is measured non-invasively through techniques such as magnetic resonance imaging (MRI). There is growing interest in detecting genetic variants associated with such multivariate traits, especially in genome-wide studies. Random forests (RFs) classifiers, which are ensembles of decision trees, are amongst the best performing machine learning algorithms and have been successfully employed for the prioritisation of genetic variants in case-control studies. RFs can also be applied to produce gene rankings in association studies with multivariate quantitative traits, and to estimate genetic similarities measures that are predictive of the trait. However, in studies involving hundreds of thousands of SNPs and high-dimensional traits, a very large ensemble of trees must be inferred from the data in order to obtain reliable rankings, which makes the application of these algorithms computationally prohibitive. Results We have developed a parallel version of the RF algorithm for regression and genetic similarity learning tasks in large-scale population genetic association studies involving multivariate traits, called PaRFR (Parallel Random Forest Regression). Our implementation takes advantage of the MapReduce programming model and is deployed on Hadoop, an open-source software framework that supports data-intensive distributed applications. Notable speed-ups are obtained by introducing a distance-based criterion for node splitting in the tree estimation process. PaRFR has been applied to a genome-wide association study on Alzheimer's disease (AD) in which the quantitative trait consists of a high-dimensional neuroimaging phenotype describing longitudinal changes in the human brain structure. PaRFR provides a ranking of SNPs associated to this trait, and produces pair-wise measures of genetic proximity

  13. Predictors of Abnormal Neuroimaging of the Brain in Children With Epilepsy Aged 1 Month to 2 Years: Useful Clues in a Resource-Limited Setting.

    PubMed

    Sanmaneechai, Oranee; Danchaivijitr, Nasuda; Likasitwattanakul, Surachai

    2015-10-01

    Neuroimaging should be performed on infants with seizure. However, there are economic limitations in performing neuroimaging in a resource-limited setting. The younger the age, the higher the risk of having abnormal neuroimaging. The aim was to determine frequency and predictors of abnormal neuroimaging in children with epilepsy aged 1 month to 2 years. History, physical examination, electroencephalogram (EEG), and neuroimaging were reviewed. Thirty-seven of 49 (76%) had neuroimaging studies; 19 computed tomography (CT), 14 magnetic resonance imaging (MRI), and 4 had both. Abnormal neuroimaging was found in 19 (51%). Predictors of abnormal neuroimages are developmental delay, abnormal head circumference, and abnormal neurologic examination. Eight children (21%) had lesions on neuroimaging studies that altered or influenced management. Of 8 patients with normal examination and EEG, 1 had a brain tumor and another had arteriovenous malformation. Neuroimaging should be considered as an essential aid in the evaluation of infants with epilepsy, even in a resource-limited setting. PMID:25792429

  14. The functional neuroimaging correlates of psychogenic versus organic dystonia.

    PubMed

    Schrag, Anette E; Mehta, Arpan R; Bhatia, Kailash P; Brown, Richard J; Frackowiak, Richard S J; Trimble, Michael R; Ward, Nicholas S; Rowe, James B

    2013-03-01

    The neurobiological basis of psychogenic movement disorders remains poorly understood and the management of these conditions difficult. Functional neuroimaging studies have provided some insight into the pathophysiology of disorders implicating particularly the prefrontal cortex, but there are no studies on psychogenic dystonia, and comparisons with findings in organic counterparts are rare. To understand the pathophysiology of these disorders better, we compared the similarities and differences in functional neuroimaging of patients with psychogenic dystonia and genetically determined dystonia, and tested hypotheses on the role of the prefrontal cortex in functional neurological disorders. Patients with psychogenic (n = 6) or organic (n = 5, DYT1 gene mutation positive) dystonia of the right leg, and matched healthy control subjects (n = 6) underwent positron emission tomography of regional cerebral blood flow. Participants were studied during rest, during fixed posturing of the right leg and during paced ankle movements. Continuous surface electromyography and footplate manometry monitored task performance. Averaging regional cerebral blood flow across all tasks, the organic dystonia group showed abnormal increases in the primary motor cortex and thalamus compared with controls, with decreases in the cerebellum. In contrast, the psychogenic dystonia group showed the opposite pattern, with abnormally increased blood flow in the cerebellum and basal ganglia, with decreases in the primary motor cortex. Comparing organic dystonia with psychogenic dystonia revealed significantly greater regional blood flow in the primary motor cortex, whereas psychogenic dystonia was associated with significantly greater blood flow in the cerebellum and basal ganglia (all P < 0.05, family-wise whole-brain corrected). Group × task interactions were also examined. During movement, compared with rest, there was abnormal activation in the right dorsolateral prefrontal cortex that was

  15. How can neuroimaging facilitate the diagnosis and stratification of patients with psychosis?

    PubMed Central

    Kempton, Matthew J.; McGuire, Philip

    2015-01-01

    Early diagnosis and treatment of patients with psychosis are associated with improved outcome in terms of future functioning, symptoms and treatment response. Identifying neuroimaging biomarkers for illness onset and treatment response would lead to immediate clinical benefits. In this review we discuss if neuroimaging may be utilised to diagnose patients with psychosis, predict those who will develop the illness in those at high risk, and stratify patients. State-of-the-art developments in the field are critically examined including multicentre studies, longitudinal designs, multimodal imaging and machine learning as well as some of the challenges in utilising future neuroimaging biomarkers in clinical trials. As many of these developments are already being applied in neuroimaging studies of Alzheimer׳s disease, we discuss what lessons have been learned from this field and how they may be applied to research in psychosis. PMID:25092428

  16. Neuroimaging Studies of Normal Brain Development and Their Relevance for Understanding Childhood Neuropsychiatric Disorders

    ERIC Educational Resources Information Center

    Marsh, Rachel; Gerber, Andrew J.; Peterson, Bradley S.

    2008-01-01

    Neuroimaging findings which identify normal brain development trajectories are presented. Results show that early brain development begins with the neural tube formation and ends with myelintation. How disturbances in brain development patterns are related to childhood psychiatric disorders is examined.

  17. [Relevance of neuroimaging findings for diagnoses and treatment of adolescent anorexia nervosa].

    PubMed

    Konrad, Kerstin

    2015-01-01

    Anorexia nervosa is associated with a marked loss of brain volumes during the acute stage of the disease. Due to the advances in neuroimaging methods during the last years our understanding of the consequences of starvation and the etiology of eating disorders has increased considerably, however, still the clinical relevance of these findings is limited. Thus, some future perspectives of neuroimaging findings for diagnoses and treatment of anorexia nervosa are summarized in the current review. PMID:25594269

  18. Visual Systems for Interactive Exploration and Mining of Large-Scale Neuroimaging Data Archives

    PubMed Central

    Bowman, Ian; Joshi, Shantanu H.; Van Horn, John D.

    2012-01-01

    While technological advancements in neuroimaging scanner engineering have improved the efficiency of data acquisition, electronic data capture methods will likewise significantly expedite the populating of large-scale neuroimaging databases. As they do and these archives grow in size, a particular challenge lies in examining and interacting with the information that these resources contain through the development of compelling, user-driven approaches for data exploration and mining. In this article, we introduce the informatics visualization for neuroimaging (INVIZIAN) framework for the graphical rendering of, and dynamic interaction with the contents of large-scale neuroimaging data sets. We describe the rationale behind INVIZIAN, detail its development, and demonstrate its usage in examining a collection of over 900 T1-anatomical magnetic resonance imaging (MRI) image volumes from across a diverse set of clinical neuroimaging studies drawn from a leading neuroimaging database. Using a collection of cortical surface metrics and means for examining brain similarity, INVIZIAN graphically displays brain surfaces as points in a coordinate space and enables classification of clusters of neuroanatomically similar MRI images and data mining. As an initial step toward addressing the need for such user-friendly tools, INVIZIAN provides a highly unique means to interact with large quantities of electronic brain imaging archives in ways suitable for hypothesis generation and data mining. PMID:22536181

  19. Responsible Reporting: Neuroimaging News in the Age of Responsible Research and Innovation.

    PubMed

    de Jong, Irja Marije; Kupper, Frank; Arentshorst, Marlous; Broerse, Jacqueline

    2016-08-01

    Besides offering opportunities in both clinical and non-clinical domains, the application of novel neuroimaging technologies raises pressing dilemmas. 'Responsible Research and Innovation' (RRI) aims to stimulate research and innovation activities that take ethical and social considerations into account from the outset. We previously identified that Dutch neuroscientists interpret "responsible innovation" as educating the public on neuroimaging technologies via the popular press. Their aim is to mitigate (neuro)hype, an aim shared with the wider emerging RRI community. Here, we present results of a media-analysis undertaken to establish whether the body of articles in the Dutch popular press presents balanced conversations on neuroimaging research to the public. We found that reporting was mostly positive and framed in terms of (healthcare) progress. There was rarely a balance between technology opportunities and limitations, and even fewer articles addressed societal or ethical aspects of neuroimaging research. Furthermore, neuroimaging metaphors seem to favour oversimplification. Current reporting is therefore more likely to enable hype than to mitigate it. How can neuroscientists, given their self-ascribed social responsibility, address this conundrum? We make a case for a collective and shared responsibility among neuroscientists, journalists and other stakeholders, including funders, committed to responsible reporting on neuroimaging research. PMID:26208573

  20. Heads in the Cloud: A Primer on Neuroimaging Applications of High Performance Computing

    PubMed Central

    Shatil, Anwar S.; Younas, Sohail; Pourreza, Hossein; Figley, Chase R.

    2015-01-01

    With larger data sets and more sophisticated analyses, it is becoming increasingly common for neuroimaging researchers to push (or exceed) the limitations of standalone computer workstations. Nonetheless, although high-performance computing platforms such as clusters, grids and clouds are already in routine use by a small handful of neuroimaging researchers to increase their storage and/or computational power, the adoption of such resources by the broader neuroimaging community remains relatively uncommon. Therefore, the goal of the current manuscript is to: 1) inform prospective users about the similarities and differences between computing clusters, grids and clouds; 2) highlight their main advantages; 3) discuss when it may (and may not) be advisable to use them; 4) review some of their potential problems and barriers to access; and finally 5) give a few practical suggestions for how interested new users can start analyzing their neuroimaging data using cloud resources. Although the aim of cloud computing is to hide most of the complexity of the infrastructure management from end-users, we recognize that this can still be an intimidating area for cognitive neuroscientists, psychologists, neurologists, radiologists, and other neuroimaging researchers lacking a strong computational background. Therefore, with this in mind, we have aimed to provide a basic introduction to cloud computing in general (including some of the basic terminology, computer architectures, infrastructure and service models, etc.), a practical overview of the benefits and drawbacks, and a specific focus on how cloud resources can be used for various neuroimaging applications. PMID:27279746

  1. A review of neuroimaging findings in repetitive brain trauma.

    PubMed

    Koerte, Inga K; Lin, Alexander P; Willems, Anna; Muehlmann, Marc; Hufschmidt, Jakob; Coleman, Michael J; Green, Isobel; Liao, Huijun; Tate, David F; Wilde, Elisabeth A; Pasternak, Ofer; Bouix, Sylvain; Rathi, Yogesh; Bigler, Erin D; Stern, Robert A; Shenton, Martha E

    2015-05-01

    Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease confirmed at postmortem. Those at highest risk are professional athletes who participate in contact sports and military personnel who are exposed to repetitive blast events. All neuropathologically confirmed CTE cases, to date, have had a history of repetitive head impacts. This suggests that repetitive head impacts may be necessary for the initiation of the pathogenetic cascade that, in some cases, leads to CTE. Importantly, while all CTE appears to result from repetitive brain trauma, not all repetitive brain trauma results in CTE. Magnetic resonance imaging has great potential for understanding better the underlying mechanisms of repetitive brain trauma. In this review, we provide an overview of advanced imaging techniques currently used to investigate brain anomalies. We also provide an overview of neuroimaging findings in those exposed to repetitive head impacts in the acute/subacute and chronic phase of injury and in more neurodegenerative phases of injury, as well as in military personnel exposed to repetitive head impacts. Finally, we discuss future directions for research that will likely lead to a better understanding of the underlying mechanisms separating those who recover from repetitive brain trauma vs. those who go on to develop CTE. PMID:25904047

  2. On the role of general system theory for functional neuroimaging

    PubMed Central

    Stephan, Klaas Enno

    2004-01-01

    One of the most important goals of neuroscience is to establish precise structure–function relationships in the brain. Since the 19th century, a major scientific endeavour has been to associate structurally distinct cortical regions with specific cognitive functions. This was traditionally accomplished by correlating microstructurally defined areas with lesion sites found in patients with specific neuropsychological symptoms. Modern neuroimaging techniques with high spatial resolution have promised an alternative approach, enabling non-invasive measurements of regionally specific changes of brain activity that are correlated with certain components of a cognitive process. Reviewing classic approaches towards brain structure–function relationships that are based on correlational approaches, this article argues that these approaches are not sufficient to provide an understanding of the operational principles of a dynamic system such as the brain but must be complemented by models based on general system theory. These models reflect the connectional structure of the system under investigation and emphasize context-dependent couplings between the system elements in terms of effective connectivity. The usefulness of system models whose parameters are fitted to measured functional imaging data for testing hypotheses about structure–function relationships in the brain and their potential for clinical applications is demonstrated by several empirical examples. PMID:15610393

  3. Integrated feature extraction and selection for neuroimage classification

    NASA Astrophysics Data System (ADS)

    Fan, Yong; Shen, Dinggang

    2009-02-01

    Feature extraction and selection are of great importance in neuroimage classification for identifying informative features and reducing feature dimensionality, which are generally implemented as two separate steps. This paper presents an integrated feature extraction and selection algorithm with two iterative steps: constrained subspace learning based feature extraction and support vector machine (SVM) based feature selection. The subspace learning based feature extraction focuses on the brain regions with higher possibility of being affected by the disease under study, while the possibility of brain regions being affected by disease is estimated by the SVM based feature selection, in conjunction with SVM classification. This algorithm can not only take into account the inter-correlation among different brain regions, but also overcome the limitation of traditional subspace learning based feature extraction methods. To achieve robust performance and optimal selection of parameters involved in feature extraction, selection, and classification, a bootstrapping strategy is used to generate multiple versions of training and testing sets for parameter optimization, according to the classification performance measured by the area under the ROC (receiver operating characteristic) curve. The integrated feature extraction and selection method is applied to a structural MR image based Alzheimer's disease (AD) study with 98 non-demented and 100 demented subjects. Cross-validation results indicate that the proposed algorithm can improve performance of the traditional subspace learning based classification.

  4. Clinical and Neuroimaging Findings of Sydenham’s Chorea

    PubMed Central

    Ekici, Arzu; Yakut, Ayten; Yimenicioglu, Sevgi; Bora Carman, Kursat; Saylısoy, Suzan

    2014-01-01

    Objective: Sydenham’s chorea (SC) is thought to be an autoimmune disorder. MRI is generally used to exclude other causes of chorea. There are no typically defined MRI features of SC. In this study we aimed to determine clinical and neuroimaging findings of SC. Methods: In this study 17 patients with acute SC were retrospectively evaluated. Sydenham’s chorea was diagnosed according to the 1992 revision of the Jones criteria. The other causes of chorea were excluded. Cranial MRI was performed in all patients during the acute phase of SC. Walking, speech and swallowing disorders, muscle weakness, behavioral disorders, treatment, symptom recovery time and recurrence were evaluated. Findings : The patients’ mean age was 11.2 years. Behavioral changes, muscle weakness and dysphagia occurred in 70%, 64% and 23% of the patients, respectively. Nonspecific signal hyperintensities were observed in the white matter, brain stem and caudate nucleus in 47% of patients. Two patients who had chorea paralytica were treated successfully with a high dose of intravenous methylprednisolone. Conclusion: Nonspecific hyperintense white matter abnormalities may be due to the inflammatory process associated with a longer duration of clinical signs. To explain the MRI findings and the pathogenesis of SC, comprehensive studies are needed. PMID:25562024

  5. Role of Neuroimaging in the Presurgical Evaluation of Epilepsy

    PubMed Central

    Lüders, Hans

    2008-01-01

    A significant minority of patients with focal epilepsy are candidates for resective epilepsy surgery. Structural and functional neuroimaging plays an important role in the presurgical evaluation of theses patients. The most frequent etiologies of pharmacoresistant epilepsy in the adult population are mesial temporal sclerosis, malformations of cortical development, cavernous angiomas, and low-grade neoplasms. High-resolution multiplanar magnetic resonance imaging (MRI) with sequences providing T1 and T2 contrast is the initial imaging study of choice to detect these epileptogenic lesions. The epilepsy MRI protocol can be individually tailored when considering the patient's clinical and electrophysiological data. Metabolic imaging techniques such as positron emission tomography (PET) and single photon emission tomography (SPECT) visualize metabolic alterations of the brain in the ictal and interictal states. These techniques may have localizing value in patients with a normal MRI scan. Functional MRI is helpful in non-invasively identifying areas of eloquent cortex. Developments in imaging technology and digital postprocessing may increase the yield for imaging studies to detect the epileptogenic lesion and to characterize its connectivity within the epileptic brain. PMID:19513318

  6. Spatially Varying Coefficient Model for Neuroimaging Data with Jump Discontinuities

    PubMed Central

    Zhu, Hongtu; Fan, Jianqing; Kong, Linglong

    2014-01-01

    Motivated by recent work on studying massive imaging data in various neuroimaging studies, we propose a novel spatially varying coefficient model (SVCM) to capture the varying association between imaging measures in a three-dimensional (3D) volume (or 2D surface) with a set of covariates. Two stylized features of neuorimaging data are the presence of multiple piecewise smooth regions with unknown edges and jumps and substantial spatial correlations. To specifically account for these two features, SVCM includes a measurement model with multiple varying coefficient functions, a jumping surface model for each varying coefficient function, and a functional principal component model. We develop a three-stage estimation procedure to simultaneously estimate the varying coefficient functions and the spatial correlations. The estimation procedure includes a fast multiscale adaptive estimation and testing procedure to independently estimate each varying coefficient function, while preserving its edges among different piecewise-smooth regions. We systematically investigate the asymptotic properties (e.g., consistency and asymptotic normality) of the multiscale adaptive parameter estimates. We also establish the uniform convergence rate of the estimated spatial covariance function and its associated eigenvalues and eigenfunctions. Our Monte Carlo simulation and real data analysis have confirmed the excellent performance of SVCM. PMID:25435598

  7. Neuroimaging in adult penetrating brain injury: a guide for radiographers

    SciTech Connect

    Temple, Nikki; Donald, Cortny; Skora, Amanda; Reed, Warren

    2015-06-15

    Penetrating brain injuries (PBI) are a medical emergency, often resulting in complex damage and high mortality rates. Neuroimaging is essential to evaluate the location and extent of injuries, and to manage them accordingly. Currently, a myriad of imaging modalities are included in the diagnostic workup for adult PBI, including skull radiography, computed tomography (CT), magnetic resonance imaging (MRI) and angiography, with each modality providing their own particular benefits. This literature review explores the current modalities available for investigating PBI and aims to assist in decision making for the appropriate use of diagnostic imaging when presented with an adult PBI. Based on the current literature, the authors have developed an imaging pathway for adult penetrating brain injury that functions as both a learning tool and reference guide for radiographers and other health professionals. Currently, CT is recommended as the imaging modality of choice for the initial assessment of PBI patients, while MRI is important in the sub-acute setting where it aids prognosis prediction and rehabilitation planning, Additional follow-up imaging, such as angiography, should be dependent upon clinical findings.

  8. Developing High-Density Diffuse Optical Tomography for Neuroimaging

    NASA Astrophysics Data System (ADS)

    White, Brian Richard

    Clinicians who care for brain-injured patients and premature infants desire a bedside monitor of brain function. A decade ago, there was hope that optical imaging would be able to fill this role, as it combined fMRI's ability to construct cortical maps with EEG's portable, cap-based systems. However, early optical systems had poor imaging performance, and the momentum for the technique slowed. In our lab, we develop diffuse optical tomography (DOT), which is a more advanced method of performing optical imaging. My research has been to pioneer the in vivo use of DOT for advanced neuroimaging by (1) quantifying the advantages of DOT through both in silico simulation and in vivo performance metrics, (2) restoring confidence in the technique with the first retinotopic mapping of the visual cortex (a benchmark for fMRI and PET), and (3) creating concepts and methods for the clinical translation of DOT. Hospitalized patients are unable to perform complicated neurological tasks, which has motivated us to develop the first DOT methods for resting-state brain mapping with functional connectivity. Finally, in collaboration with neonatologists, I have extended these methods with proof-of-principle imaging of brain-injured premature infants. This work establishes DOT's improvements in imaging performance and readies it for multiple clinical and research roles.

  9. Hemimegalencephaly: Clinical, EEG, neuroimaging, and IMP-SPECT correlation

    SciTech Connect

    Konkol, R.J.; Maister, B.H.; Wells, R.G.; Sty, J.R. )

    1990-11-01

    Iofetamine-single photon emission computed tomography (IMP-SPECT) was performed on 2 girls (5 1/2 and 6 years of age) with histories of intractable seizures, developmental delay, and unilateral hemiparesis secondary to hemimegalencephaly. Electroencephalography (EEG) revealed frequent focal discharges in 1 patient, while a nearly continuous burst suppression pattern over the malformed hemisphere was recorded in the other. IMP-SPECT demonstrated a good correlation with neuroimaging studies. In spite of the different EEG patterns, which had been proposed to predict contrasting clinical outcomes, both IMP-SPECT scans disclosed a similar decrease in tracer uptake in the malformed hemisphere. These results are consistent with the pattern of decreased tracer uptake found in other interictal studies of focal seizures without cerebral malformations. In view of recent recommendations for hemispherectomy in these patients, we suggest that the IMP-SPECT scan be used to compliment EEG as a method to define the extent of abnormality which may be more relevant to long-term prognosis than EEG alone.

  10. When encoding yields remembering: insights from event-related neuroimaging.

    PubMed Central

    Wagner, A D; Koutstaal, W; Schacter, D L

    1999-01-01

    To understand human memory, it is important to determine why some experiences are remembered whereas others are forgotten. Until recently, insights into the neural bases of human memory encoding, the processes by which information is transformed into an enduring memory trace, have primarily been derived from neuropsychological studies of humans with select brain lesions. The advent of functional neuroimaging methods, such as positron emission tomography (PET) and functional magnetic resonance imaging (fMRI), has provided a new opportunity to gain additional understanding of how the brain supports memory formation. Importantly, the recent development of event-related fMRI methods now allows for examination of trial-by-trial differences in neural activity during encoding and of the consequences of these differences for later remembering. In this review, we consider the contributions of PET and fMRI studies to the understanding of memory encoding, placing a particular emphasis on recent event-related fMRI studies of the Dm effect: that is, differences in neural activity during encoding that are related to differences in subsequent memory. We then turn our attention to the rich literature on the Dm effect that has emerged from studies using event-related potentials (ERPs). It is hoped that the integration of findings from ERP studies, which offer higher temporal resolution, with those from event-related fMRI studies, which offer higher spatial resolution, will shed new light on when and why encoding yields subsequent remembering. PMID:10466153

  11. Neuroimaging in adult penetrating brain injury: a guide for radiographers.

    PubMed

    Temple, Nikki; Donald, Cortny; Skora, Amanda; Reed, Warren

    2015-06-01

    Penetrating brain injuries (PBI) are a medical emergency, often resulting in complex damage and high mortality rates. Neuroimaging is essential to evaluate the location and extent of injuries, and to manage them accordingly. Currently, a myriad of imaging modalities are included in the diagnostic workup for adult PBI, including skull radiography, computed tomography (CT), magnetic resonance imaging (MRI) and angiography, with each modality providing their own particular benefits. This literature review explores the current modalities available for investigating PBI and aims to assist in decision making for the appropriate use of diagnostic imaging when presented with an adult PBI. Based on the current literature, the authors have developed an imaging pathway for adult penetrating brain injury that functions as both a learning tool and reference guide for radiographers and other health professionals. Currently, CT is recommended as the imaging modality of choice for the initial assessment of PBI patients, while MRI is important in the sub-acute setting where it aids prognosis prediction and rehabilitation planning, Additional follow-up imaging, such as angiography, should be dependent upon clinical findings. PMID:26229677

  12. Neuroimaging studies on recognition of personally familiar people.

    PubMed

    Sugiura, Motoaki

    2014-01-01

    From an evolutionary viewpoint, readiness to engage in appropriate behavior toward a recognized person seems to be inherent in the human brain. In support of this hypothesis, functional neuroimaging studies have demonstrated activation in regions relevant to relationship-appropriate behavior during the recognition of personally familiar (PF) people. Recognition of friends and colleagues activates regions involved in real-time communication, including the regions for inference about the other's mental state, autobiographical memory retrieval, and self-referential processes. Recognition of people related by romantic love, maternal love, and lost love induces activation in regions involved in motivational, reward, and affective processes, reflecting behavioral readiness for mating, caretaking, and yearning, respectively. The involvement of motor-associated cortices during recognition of a personal enemy may reflect readiness for attack or defense. Self-recognition in a body-related modality uniquely activates sensory and motor association cortices reflecting the sensorimotor origin of the bodily self-concept, with social cognitive processes being suppressed or context dependent. Issues and future directions are also discussed. PMID:24389212

  13. Bootstrap Enhanced Penalized Regression for Variable Selection with Neuroimaging Data.

    PubMed

    Abram, Samantha V; Helwig, Nathaniel E; Moodie, Craig A; DeYoung, Colin G; MacDonald, Angus W; Waller, Niels G

    2016-01-01

    Recent advances in fMRI research highlight the use of multivariate methods for examining whole-brain connectivity. Complementary data-driven methods are needed for determining the subset of predictors related to individual differences. Although commonly used for this purpose, ordinary least squares (OLS) regression may not be ideal due to multi-collinearity and over-fitting issues. Penalized regression is a promising and underutilized alternative to OLS regression. In this paper, we propose a nonparametric bootstrap quantile (QNT) approach for variable selection with neuroimaging data. We use real and simulated data, as well as annotated R code, to demonstrate the benefits of our proposed method. Our results illustrate the practical potential of our proposed bootstrap QNT approach. Our real data example demonstrates how our method can be used to relate individual differences in neural network connectivity with an externalizing personality measure. Also, our simulation results reveal that the QNT method is effective under a variety of data conditions. Penalized regression yields more stable estimates and sparser models than OLS regression in situations with large numbers of highly correlated neural predictors. Our results demonstrate that penalized regression is a promising method for examining associations between neural predictors and clinically relevant traits or behaviors. These findings have important implications for the growing field of functional connectivity research, where multivariate methods produce numerous, highly correlated brain networks. PMID:27516732

  14. The Virtual Brain Integrates Computational Modeling and Multimodal Neuroimaging

    PubMed Central

    Schirner, Michael; McIntosh, Anthony R.; Jirsa, Viktor K.

    2013-01-01

    Abstract Brain function is thought to emerge from the interactions among neuronal populations. Apart from traditional efforts to reproduce brain dynamics from the micro- to macroscopic scales, complementary approaches develop phenomenological models of lower complexity. Such macroscopic models typically generate only a few selected—ideally functionally relevant—aspects of the brain dynamics. Importantly, they often allow an understanding of the underlying mechanisms beyond computational reproduction. Adding detail to these models will widen their ability to reproduce a broader range of dynamic features of the brain. For instance, such models allow for the exploration of consequences of focal and distributed pathological changes in the system, enabling us to identify and develop approaches to counteract those unfavorable processes. Toward this end, The Virtual Brain (TVB) (www.thevirtualbrain.org), a neuroinformatics platform with a brain simulator that incorporates a range of neuronal models and dynamics at its core, has been developed. This integrated framework allows the model-based simulation, analysis, and inference of neurophysiological mechanisms over several brain scales that underlie the generation of macroscopic neuroimaging signals. In this article, we describe how TVB works, and we present the first proof of concept. PMID:23442172

  15. Applying neuroimaging to detect neuroanatomical dysconnectivity in psychosis.

    PubMed

    O'Donoghue, S; Cannon, D M; Perlini, C; Brambilla, P; McDonald, C

    2015-08-01

    This editorial discusses the application of a novel brain imaging analysis technique in the assessment of neuroanatomical dysconnectivity in psychotic illnesses. There has long been a clinical interest in psychosis as a disconnection syndrome. In recent years graph theory metrics have been applied to functional and structural imaging datasets to derive measures of brain connectivity, which represent the efficiency of brain networks. These metrics can be derived from structural neuroimaging datasets acquired using diffusion imaging whereby cortical structures are parcellated into nodes and white matter tracts represent edges connecting these nodes. Furthermore neuroanatomical measures of connectivity may be decoupled from measures of physiological connectivity as assessed using functional imaging, underpinning the need for multi-modal imaging approaches to probe brain networks. Studies to date have reported a number of structural brain connectivity abnormalities associated with schizophrenia that carry potential as illness biomarkers. Structural connectivity abnormalities have also been reported in well patients with bipolar disorder and in unaffected relatives of patients with schizophrenia. Such connectivity metrics may represent clinically relevant biomarkers in studies employing a longitudinal design of illness course in psychosis. PMID:25672250

  16. Bootstrap Enhanced Penalized Regression for Variable Selection with Neuroimaging Data

    PubMed Central

    Abram, Samantha V.; Helwig, Nathaniel E.; Moodie, Craig A.; DeYoung, Colin G.; MacDonald, Angus W.; Waller, Niels G.

    2016-01-01

    Recent advances in fMRI research highlight the use of multivariate methods for examining whole-brain connectivity. Complementary data-driven methods are needed for determining the subset of predictors related to individual differences. Although commonly used for this purpose, ordinary least squares (OLS) regression may not be ideal due to multi-collinearity and over-fitting issues. Penalized regression is a promising and underutilized alternative to OLS regression. In this paper, we propose a nonparametric bootstrap quantile (QNT) approach for variable selection with neuroimaging data. We use real and simulated data, as well as annotated R code, to demonstrate the benefits of our proposed method. Our results illustrate the practical potential of our proposed bootstrap QNT approach. Our real data example demonstrates how our method can be used to relate individual differences in neural network connectivity with an externalizing personality measure. Also, our simulation results reveal that the QNT method is effective under a variety of data conditions. Penalized regression yields more stable estimates and sparser models than OLS regression in situations with large numbers of highly correlated neural predictors. Our results demonstrate that penalized regression is a promising method for examining associations between neural predictors and clinically relevant traits or behaviors. These findings have important implications for the growing field of functional connectivity research, where multivariate methods produce numerous, highly correlated brain networks. PMID:27516732

  17. Neuroimaging in basal ganglia disorders: perspectives for transcranial ultrasound.

    PubMed

    Becker, G; Berg, D

    2001-01-01

    Transcranial sonography is a new diagnostic tool, allowing not only the evaluation of cerebral arteries but also the two-dimensional display of the brain parenchyma. In this review we will summarize basics of the application, the ultrasound anatomy of the brain and sonographic findings in some movement disorders. While in normal adults basal ganglia nuclei are hypoechogenic, they are hyperechogenic in certain basal ganglia disorders. In Parkinson's disease, for example, the substantia nigra can be depicted as a distinctly echogenic area. An elevated echogenicity of the lentiform nuclei was noticed in patients with primary adult-onset dystonia. In both disorders the altered echogenicity may arise from higher heavy metal tissue content (i.e. iron in Parkinson's disease and copper in primary dystonia). Our findings converge to the hypothesis that transcranial ultrasound sensitively detects pathological metal accumulation not identified by other neuroimaging techniques (CT and MRI) and therefore provides new insights in the diagnosis of basal ganglia disorders. The implications of these findings for the understanding of the pathogenesis and its usefulness for the early diagnosis of movement disorders are outlined. PMID:11215589

  18. Neuroimaging and neurocognitive correlates of aggression and violence in schizophrenia.

    PubMed

    Weiss, Elisabeth M

    2012-01-01

    Individuals diagnosed with major mental disorders such as schizophrenia are more likely to have engaged in violent behavior than mentally healthy members of the same communities. Although aggressive acts can have numerous causes, research about the underlying neurobiology of violence and aggression in schizophrenia can lead to a better understanding of the heterogeneous nature of that behavior and can assist in developing new treatment strategies. The purpose of this paper is to review the recent literature and discuss some of the neurobiological correlates of aggression and violence. The focus will be on schizophrenia, and the results of neuroimaging and neuropsychological studies that have directly investigated brain functioning and/or structure in aggressive and violent samples will be discussed as well as other domains that might predispose to aggression and violence such as deficits in responding to the emotional expressions of others, impulsivity, and psychopathological symptoms. Finally gender differences regarding aggression and violence are discussed. In this context several methodological and conceptional issues that limited the comparison of these studies will be addressed. PMID:24278673

  19. Choroid plexus calcification: clinical, neuroimaging and histopathological correlations in schizophrenia.

    PubMed

    Marinescu, Ileana; Udriştoiu, I; Marinescu, D

    2013-01-01

    Schizophrenia is recognized as a psychiatric disorder that causes the most pronounced disturbances of cognition and social integration. In the etiopathogenesis of the disease, genetic, neurobiological and vascular factors are involved. Functional integrity of the brain can be correlated with the integrity of the blood-brain barrier (BBB), and the dysfunction of this barrier is an indicator that suggests neurodevelopmental abnormalities, injuries of various etiologies and dysfunctions within the small vessels of the brain that disrupt the calcium homeostasis. Neuroimaging shows that in patients with poor evolution, cognitive dysfunction and therapeutic resistance, the presence of choroid plexus calcification associated with hippocampal, frontal, temporoparietal and cerebellar atrophies. Antipsychotics with high capacity to block D2 dopamine receptors (haloperidol model) can aggravate apoptotic mechanisms of the brain areas involved in cognition and disrupts the functional integrity of the BBB due to decreased of choroid plexus blood flow because of the narrowing of cerebral small vessels. Choroid plexus calcification may be a predictive indicator of poor evolution or of a neurodegenerative type. PMID:23771083

  20. Neuroimaging and Neurocognitive Correlates of Aggression and Violence in Schizophrenia

    PubMed Central

    Weiss, Elisabeth M.

    2012-01-01

    Individuals diagnosed with major mental disorders such as schizophrenia are more likely to have engaged in violent behavior than mentally healthy members of the same communities. Although aggressive acts can have numerous causes, research about the underlying neurobiology of violence and aggression in schizophrenia can lead to a better understanding of the heterogeneous nature of that behavior and can assist in developing new treatment strategies. The purpose of this paper is to review the recent literature and discuss some of the neurobiological correlates of aggression and violence. The focus will be on schizophrenia, and the results of neuroimaging and neuropsychological studies that have directly investigated brain functioning and/or structure in aggressive and violent samples will be discussed as well as other domains that might predispose to aggression and violence such as deficits in responding to the emotional expressions of others, impulsivity, and psychopathological symptoms. Finally gender differences regarding aggression and violence are discussed. In this context several methodological and conceptional issues that limited the comparison of these studies will be addressed. PMID:24278673

  1. Neurocognition and neuroimaging of persistent negative symptoms of schizophrenia.

    PubMed

    Hovington, Cindy L; Lepage, Martin

    2012-01-01

    Negative symptoms have been a conundrum to researchers and clinicians alike since having first been identified by Bleuler and Kraepelin. The term 'negative symptoms' has been scrutinized with regards to what it encompasses. Negative symptomatology has been categorized into distinct subdomains, including primary symptoms, secondary symptoms, deficit syndrome and, more recently, persistent negative symptoms (PNS). Although there have been some theories put forward with regards to negative symptoms, there are still discordant findings regarding PNS. Thus, this article aimed to review the structural, functional and cognitive correlates of PNS in an attempt to better understand these specific negative symptoms in schizophrenia. According to the reviewed literature, deficit syndrome appears to have similar neurocognitive and structural deficits as PNS; however, some minor distinctions may suggest that PNS are a separate subtype of negative symptoms. White matter decrements in the frontal lobe and gray matter reductions in the temporal lobe may be related more specifically to PNS. Furthermore, unlike deficit syndrome, structural abnormalities in the frontal and temporal lobe also appear to be related to PNS in patients with first-episode schizophrenia. Cognitive domains, such as memory, are impaired and appear to be predominantly related to PNS. Hence, PNS do appear to have neuroimaging and neurocognitive correlates and warrant further research. PMID:22243045

  2. Behavioral endophenotypes of drug addiction: Etiological insights from neuroimaging studies.

    PubMed

    Jupp, Bianca; Dalley, Jeffrey W

    2014-01-01

    This article reviews recent advances in the elucidation of neurobehavioral endophenotypes associated with drug addiction made possible by the translational neuroimaging techniques magnetic resonance imaging (MRI) and positron emission tomography (PET). Increasingly, these non-invasive imaging approaches have been the catalyst for advancing our understanding of the etiology of drug addiction as a brain disorder involving complex interactions between pre-disposing behavioral traits, environmental influences and neural perturbations arising from the chronic abuse of licit and illicit drugs. In this article we discuss the causal role of trait markers associated with impulsivity and novelty-/sensation-seeking in speeding the development of compulsive drug administration and in facilitating relapse. We also discuss the striking convergence of imaging findings from these behavioural traits and addiction in rats, monkeys and humans with a focus on biomarkers of dopamine neurotransmission, and highlight areas where further research is needed to disambiguate underlying causal mechanisms. This article is part of a Special Issue entitled 'NIDA 40th Anniversary Issue'. PMID:23756169

  3. Understanding the minds of others: A neuroimaging meta-analysis.

    PubMed

    Molenberghs, Pascal; Johnson, Halle; Henry, Julie D; Mattingley, Jason B

    2016-06-01

    Theory of mind (ToM) is an important skill that refers broadly to the capacity to understand the mental states of others. A large number of neuroimaging studies have focused on identifying the functional brain regions involved in ToM, but many important questions remain with respect to the neural networks implicated in specific types of ToM tasks. In the present study, we conducted a series of activation likelihood estimation (ALE) meta-analyses on 144 datasets (involving 3150 participants) to address these questions. The ALE results revealed common regions shared across all ToM tasks and broader task parameters, but also some important dissociations. In terms of commonalities, consistent activation was identified in the medial prefrontal cortex and bilateral temporoparietal junction. On the other hand, ALE contrast analyses on our dataset, as well as meta-analytic connectivity modelling (MACM) analyses on the BrainMap database, indicated that different types of ToM tasks reliably elicit activity in unique brain areas. Our findings provide the most accurate picture to date of the neural networks that underpin ToM function. PMID:27073047

  4. The extended fronto-striatal model of obsessive compulsive disorder: convergence from event-related potentials, neuropsychology and neuroimaging.

    PubMed

    Melloni, Margherita; Urbistondo, Claudia; Sedeño, Lucas; Gelormini, Carlos; Kichic, Rafael; Ibanez, Agustin

    2012-01-01

    In this work, we explored convergent evidence supporting the fronto-striatal model of obsessive-compulsive disorder (FSMOCD) and the contribution of event-related potential (ERP) studies to this model. First, we considered minor modifications to the FSMOCD model based on neuroimaging and neuropsychological data. We noted the brain areas most affected in this disorder -anterior cingulate cortex (ACC), basal ganglia (BG), and orbito-frontal cortex (OFC) and their related cognitive functions, such as monitoring and inhibition. Then, we assessed the ERPs that are directly related to the FSMOCD, including the error-related negativity (ERN), N200, and P600. Several OCD studies present enhanced ERN and N2 responses during conflict tasks as well as an enhanced P600 during working memory (WM) tasks. Evidence from ERP studies (especially regarding ERN and N200 amplitude enhancement), neuroimaging and neuropsychological findings suggests abnormal activity in the OFC, ACC, and BG in OCD patients. Moreover, additional findings from these analyses suggest dorsolateral prefrontal and parietal cortex involvement, which might be related to executive function (EF) deficits. Thus, these convergent results suggest the existence of a self-monitoring imbalance involving inhibitory deficits and executive dysfunctions. OCD patients present an impaired ability to monitor, control, and inhibit intrusive thoughts, urges, feelings, and behaviors. In the current model, this imbalance is triggered by an excitatory role of the BG (associated with cognitive or motor actions without volitional control) and inhibitory activity of the OFC as well as excessive monitoring of the ACC to block excitatory impulses. This imbalance would interact with the reduced activation of the parietal-DLPC network, leading to executive dysfunction. ERP research may provide further insight regarding the temporal dynamics of action monitoring and executive functioning in OCD. PMID:23015786

  5. The extended fronto-striatal model of obsessive compulsive disorder: convergence from event-related potentials, neuropsychology and neuroimaging

    PubMed Central

    Melloni, Margherita; Urbistondo, Claudia; Sedeño, Lucas; Gelormini, Carlos; Kichic, Rafael; Ibanez, Agustin

    2012-01-01

    In this work, we explored convergent evidence supporting the fronto-striatal model of obsessive-compulsive disorder (FSMOCD) and the contribution of event-related potential (ERP) studies to this model. First, we considered minor modifications to the FSMOCD model based on neuroimaging and neuropsychological data. We noted the brain areas most affected in this disorder -anterior cingulate cortex (ACC), basal ganglia (BG), and orbito-frontal cortex (OFC) and their related cognitive functions, such as monitoring and inhibition. Then, we assessed the ERPs that are directly related to the FSMOCD, including the error-related negativity (ERN), N200, and P600. Several OCD studies present enhanced ERN and N2 responses during conflict tasks as well as an enhanced P600 during working memory (WM) tasks. Evidence from ERP studies (especially regarding ERN and N200 amplitude enhancement), neuroimaging and neuropsychological findings suggests abnormal activity in the OFC, ACC, and BG in OCD patients. Moreover, additional findings from these analyses suggest dorsolateral prefrontal and parietal cortex involvement, which might be related to executive function (EF) deficits. Thus, these convergent results suggest the existence of a self-monitoring imbalance involving inhibitory deficits and executive dysfunctions. OCD patients present an impaired ability to monitor, control, and inhibit intrusive thoughts, urges, feelings, and behaviors. In the current model, this imbalance is triggered by an excitatory role of the BG (associated with cognitive or motor actions without volitional control) and inhibitory activity of the OFC as well as excessive monitoring of the ACC to block excitatory impulses. This imbalance would interact with the reduced activation of the parietal-DLPC network, leading to executive dysfunction. ERP research may provide further insight regarding the temporal dynamics of action monitoring and executive functioning in OCD. PMID:23015786

  6. Neuroimaging studies of the striatum in cognition Part I: healthy individuals

    PubMed Central

    Provost, Jean-Sebastien; Hanganu, Alexandru; Monchi, Oury

    2015-01-01

    The striatum has traditionally mainly been associated with playing a key role in the modulation of motor functions. Indeed, lesion studies in animals and studies of some neurological conditions in humans have brought further evidence to this idea. However, better methods of investigation have raised concerns about this notion, and it was proposed that the striatum could also be involved in different types of functions including cognitive ones. Although the notion was originally a matter of debate, it is now well-accepted that the caudate nucleus contributes to cognition, while the putamen could be involved in motor functions, and to some extent in cognitive functions as well. With the arrival of modern neuroimaging techniques in the early 1990, knowledge supporting the cognitive aspect of the striatum has greatly increased, and a substantial number of scientific papers were published studying the role of the striatum in healthy individuals. For the first time, it was possible to assess the contribution of specific areas of the brain during the execution of a cognitive task. Neuroanatomical studies have described functional loops involving the striatum and the prefrontal cortex suggesting a specific interaction between these two structures. This review examines the data up to date and provides strong evidence for a specific contribution of the fronto-striatal regions in different cognitive processes, such as set-shifting, self-initiated responses, rule learning, action-contingency, and planning. Finally, a new two-level functional model involving the prefrontal cortex and the dorsal striatum is proposed suggesting an essential role of the dorsal striatum in selecting between competing potential responses or actions, and in resolving a high level of ambiguity. PMID:26500513

  7. Gene, Brain, and Behavior Relationships in Fragile X Syndrome: Evidence from Neuroimaging Studies

    ERIC Educational Resources Information Center

    Lightbody, Amy A.; Reiss, Allan L.

    2009-01-01

    Fragile X syndrome (FraX) remains the most common inherited cause of intellectual disability and provides a valuable model for studying gene-brain-behavior relationships. Over the past 15 years, structural and functional magnetic resonance imaging studies have emerged with the goal of better understanding the neural pathways contributing to the…

  8. Evidence from neuroimaging to explore brain plasticity in humans during an ultra-endurance burden.

    PubMed

    Perrey, Stéphane; Mandrick, Kevin

    2012-01-01

    Physical activity, likely through induction of neuroplasticity, is a promising intervention to promote brain health. In athletes it is clear that training can and does, by physiological adaptations, extend the frontiers of performance capacity. The limits of our endurance capacity lie deeply in the human brain, determined by various personal factors yet to be explored. The human brain, with its vast neural connections and its potential for seemingly endless behaviors, constitutes one of the final frontiers of medicine. In a recent study published in BMC Medicine, the TransEurope FootRace Project followed 10 ultra-endurance runners over around 4,500 km across Europe and recorded a large data collection of brain imaging scans. This study indicates that the cerebral atrophy amounting to a reduction of approximately 6% throughout the two months of the race is reversed upon follow-up. While this study will contribute to advances in the limits of human performance on the neurophysiological processes in sports scientists, it will also bring important understanding to clinicians about cerebral atrophy in people who are vulnerable to physical and psychological stress long term.See related research article http://www.biomedcentral.com/1741-7015/10/170. PMID:23259535

  9. Enhanced Left Frontal Involvement during Novel Metaphor Comprehension in Schizophrenia: Evidence from Functional Neuroimaging

    ERIC Educational Resources Information Center

    Mashal, N.; Vishne, T.; Laor, N.; Titone, D.

    2013-01-01

    The neural basis involved in novel metaphor comprehension in schizophrenia is relatively unknown. Fourteen people with schizophrenia and fourteen controls were scanned while they silently read novel metaphors, conventional metaphors, literal expressions, and meaningless word-pairs. People with schizophrenia showed reduced comprehension of both…

  10. Effects of Sex Chromosome Aneuploidies on Brain Development: Evidence from Neuroimaging Studies

    ERIC Educational Resources Information Center

    Lenroot, Rhoshel K.; Lee, Nancy Raitano; Giedd, Jay N.

    2009-01-01

    Variation in the number of sex chromosomes is a relatively common genetic condition, affecting as many as 1/400 individuals. The sex chromosome aneuploidies (SCAs) are associated with characteristic behavioral and cognitive phenotypes, although the degree to which specific individuals are affected can fall within a wide range. Understanding the…

  11. Do sentences with unaccusative verbs involve syntactic movement? Evidence from neuroimaging

    PubMed Central

    Agnew, Z.K.; van de Koot, H.; McGettigan, C.; Scott, S.K.

    2014-01-01

    This study focuses on the neural processing of English sentences containing unergative, unaccusative and transitive verbs. We demonstrate common responses in bilateral superior temporal gyri in response to listening to sentences containing unaccusative and transitive verbs compared to unergative verbs; we did not detect any activation that was specific to unaccusatives. Our findings indicate that the neural processing of unaccusative and transitive verbs is highly similar, and very different from the processing of unergative verbs. We discuss the consequences of these results for the linguistic analysis of movement phenomena. PMID:25210717

  12. Experimental Evidence for Improved Neuroimaging Interpretation Using Three-Dimensional Graphic Models

    ERIC Educational Resources Information Center

    Ruisoto, Pablo; Juanes, Juan Antonio; Contador, Israel; Mayoral, Paula; Prats-Galino, Alberto

    2012-01-01

    Three-dimensional (3D) or volumetric visualization is a useful resource for learning about the anatomy of the human brain. However, the effectiveness of 3D spatial visualization has not yet been assessed systematically. This report analyzes whether 3D volumetric visualization helps learners to identify and locate subcortical structures more…

  13. Third-generation neuroimaging in early schizophrenia: translating research evidence into clinical utility.

    PubMed

    Borgwardt, Stefan; Fusar-Poli, Paolo

    2012-04-01

    Psychiatric imaging needs to move away from simple investigations of the neurobiology underlying the early phases of schizophrenia to translate imaging findings in the clinical field, targeting clinical outcomes including transition, remission and response to preventive interventions. PMID:22474231

  14. Enhanced left frontal involvement during novel metaphor comprehension in schizophrenia: evidence from functional neuroimaging.

    PubMed

    Mashal, N; Vishne, T; Laor, N; Titone, D

    2013-01-01

    The neural basis involved in novel metaphor comprehension in schizophrenia is relatively unknown. Fourteen people with schizophrenia and fourteen controls were scanned while they silently read novel metaphors, conventional metaphors, literal expressions, and meaningless word-pairs. People with schizophrenia showed reduced comprehension of both novel and conventional metaphors. Furthermore, while controls showed enhanced brain activation in right inferior frontal gyrus (IFG) for novel metaphors versus meaningless word-pairs, people with schizophrenia showed an over-activation of left IFG and middle frontal gyrus (MFG). Direct comparison between the groups revealed greater activation in left precuneus for both novel metaphors and literal expressions vs. baseline for individuals with schizophrenia. Direct comparison for novel metaphors vs. literal expressions also revealed increased activation for individuals with schizophrenia in left MFG. These results suggest that the inefficient processing of novel metaphors in schizophrenia involves compensatory recruitment of additional brain regions that include the left MFG and left precuneus. PMID:23291493

  15. Reduced laterality as a trait marker of schizophrenia--evidence from structural and functional neuroimaging.

    PubMed

    Oertel, Viola; Knöchel, Christian; Rotarska-Jagiela, Anna; Schönmeyer, Ralf; Lindner, Michael; van de Ven, Vincent; Haenschel, Corinna; Uhlhaas, Peter; Maurer, Konrad; Linden, David E J

    2010-02-10

    Laterality is a characteristic principle of the organization of the brain systems for language, and reduced hemispheric asymmetry has been considered a risk factor for schizophrenia. Here we sought support for the risk factor hypothesis by investigating whether reduced asymmetry of temporal lobe structure and function is also present in unaffected relatives. Sixteen schizophrenia patients, 16 age-matched first-degree relatives, and 15 healthy controls underwent high-resolution three-dimensional anatomical imaging and functional magnetic resonance imaging during auditory stimulation. Both the overall auditory cortex and planum temporale volumes and the lateralization to the left hemisphere were markedly reduced in patients. The decrease of lateralization correlated with increased severity of symptoms. In addition, both the overall functional activation in response to auditory stimulation and its asymmetry were reduced in the patients. Relatives had intermediate values between patients and controls on both structural and functional measures. This study provides added support for the idea that reduced hemispheric asymmetry is a biological risk factor for schizophrenia. PMID:20147555

  16. The Impact of Disappointment in Decision Making: Inter-Individual Differences and Electrical Neuroimaging

    PubMed Central

    Tzieropoulos, Hélène; de Peralta, Rolando Grave; Bossaerts, Peter; Andino, Sara L. Gonzalez

    2011-01-01

    Disappointment, the emotion experienced when faced to reward prediction errors (RPEs), considerably impacts decision making (DM). Individuals tend to modify their behavior in an often unpredictable way just to avoid experiencing negative emotions. Despite its importance, disappointment remains much less studied than regret and its impact on upcoming decisions largely unexplored. Here, we adapted the Trust Game to effectively elicit, quantify, and isolate disappointment by relying on the formal definition provided by Bell's in economics. We evaluated the effects of experienced disappointment and elation on future cooperation and trust as well as the rationality and utility of the different behavioral and neural mechanisms used to cope with disappointment. All participants in our game trusted less and particularly expected less from unknown opponents as a result of disappointing outcomes in the previous trial but not necessarily after elation indicating that behavioral consequences of positive and negative RPEs are not the same. A large variance in the tolerance to disappointment was observed across subjects, with some participants needing only a small disappointment to impulsively bias their subsequent decisions. As revealed by high-density EEG recordings the most tolerant individuals – who thought twice before making a decision and earned more money – relied on different neural generators to contend with neutral and unexpected outcomes. This study thus provides some support to the idea that different neural systems underlie reflexive and reflective decisions within the same individuals as predicted by the dual-system theory of social judgment and DM. PMID:21258645

  17. Proactive Control Strategies for Overt and Covert Go/NoGo Tasks: An Electrical Neuroimaging Study.

    PubMed

    Angelini, Monica; Calbi, Marta; Ferrari, Annachiara; Sbriscia-Fioretti, Beatrice; Franca, Michele; Gallese, Vittorio; Umiltà, Maria Alessandra

    2016-01-01

    Proactive and reactive inhibition are generally intended as mechanisms allowing the withholding or suppression of overt movements. Nonetheless, inhibition could also play a pivotal role during covert actions (i.e., potential motor acts not overtly performed, despite the activation of the motor system), such as Motor Imagery (MI). In a previous EEG study, we analyzed cerebral activities reactively triggered during two cued Go/NoGo tasks, requiring execution or withholding of overt or covert imagined actions, respectively. This study revealed activation of pre-supplementary motor area (pre-SMA) and right inferior frontal gyrus (rIFG), key nodes of the network underpinning reactive inhibition of overt responses in NoGo trials, also during MI enactment, enabling the covert nature of the imagined motor response. Taking into account possible proactive engagement of inhibitory mechanisms by cue signals, for an exhaustive interpretation of these previous findings in the present study we analyzed EEG activities elicited during the preparatory phase of our cued overt and covert Go/NoGo tasks. Our results demonstrate a substantial overlap of cerebral areas activated during proactive recruitment and subsequent reactive implementation of motor inhibition in both overt and covert actions; also, different involvement of pre-SMA and rIFG emerged, in accord with the intended type (covert or overt) of incoming motor responses. During preparation of the overt Go/NoGo task, the cue is encoded in a pragmatic mode, as it primes the possible overt motor response programs in motor and premotor cortex and, through preactivation of a pre-SMA-related decisional mechanism, it triggers a parallel preparation for successful response selection and/or inhibition during the response phase. Conversely, the preparatory strategy for the covert Go/NoGo task is centered on priming of an inhibitory mechanism in rIFG, tuned to the instructed covert modality of motor performance and instantiated during subsequent MI, which allows the imagined response to remain a potential motor act. PMID:27010832

  18. Proactive Control Strategies for Overt and Covert Go/NoGo Tasks: An Electrical Neuroimaging Study

    PubMed Central

    Angelini, Monica; Calbi, Marta; Ferrari, Annachiara; Sbriscia-Fioretti, Beatrice; Franca, Michele; Gallese, Vittorio; Umiltà, Maria Alessandra

    2016-01-01

    Proactive and reactive inhibition are generally intended as mechanisms allowing the withholding or suppression of overt movements. Nonetheless, inhibition could also play a pivotal role during covert actions (i.e., potential motor acts not overtly performed, despite the activation of the motor system), such as Motor Imagery (MI). In a previous EEG study, we analyzed cerebral activities reactively triggered during two cued Go/NoGo tasks, requiring execution or withholding of overt or covert imagined actions, respectively. This study revealed activation of pre-supplementary motor area (pre-SMA) and right inferior frontal gyrus (rIFG), key nodes of the network underpinning reactive inhibition of overt responses in NoGo trials, also during MI enactment, enabling the covert nature of the imagined motor response. Taking into account possible proactive engagement of inhibitory mechanisms by cue signals, for an exhaustive interpretation of these previous findings in the present study we analyzed EEG activities elicited during the preparatory phase of our cued overt and covert Go/NoGo tasks. Our results demonstrate a substantial overlap of cerebral areas activated during proactive recruitment and subsequent reactive implementation of motor inhibition in both overt and covert actions; also, different involvement of pre-SMA and rIFG emerged, in accord with the intended type (covert or overt) of incoming motor responses. During preparation of the overt Go/NoGo task, the cue is encoded in a pragmatic mode, as it primes the possible overt motor response programs in motor and premotor cortex and, through preactivation of a pre-SMA-related decisional mechanism, it triggers a parallel preparation for successful response selection and/or inhibition during the response phase. Conversely, the preparatory strategy for the covert Go/NoGo task is centered on priming of an inhibitory mechanism in rIFG, tuned to the instructed covert modality of motor performance and instantiated during subsequent MI, which allows the imagined response to remain a potential motor act. PMID:27010832

  19. Semantic brain areas are involved in gesture comprehension: An electrical neuroimaging study.

    PubMed

    Proverbio, Alice Mado; Gabaro, Veronica; Orlandi, Andrea; Zani, Alberto

    2015-08-01

    While the mechanism of sign language comprehension in deaf people has been widely investigated, little is known about the neural underpinnings of spontaneous gesture comprehension in healthy speakers. Bioelectrical responses to 800 pictures of actors showing common Italian gestures (e.g., emblems, deictic or iconic gestures) were recorded in 14 persons. Stimuli were selected from a wider corpus of 1122 gestures. Half of the pictures were preceded by an incongruent description. ERPs were recorded from 128 sites while participants decided whether the stimulus was congruent. Congruent pictures elicited a posterior P300 followed by late positivity, while incongruent gestures elicited an anterior N400 response. N400 generators were investigated with swLORETA reconstruction. Processing of congruent gestures activated face- and body-related visual areas (e.g., BA19, BA37, BA22), the left angular gyrus, mirror fronto/parietal areas. The incongruent-congruent contrast particularly stimulated linguistic and semantic brain areas, such as the left medial and the superior temporal lobe. PMID:26011745

  20. [Functional Neuroimaging Pilot Study of Borderline Personality Disorder in Adolescents].

    PubMed

    LeBoeuf, Amélie; Guilé, Jean-Marc; Labelle, Réal; Luck, David

    2016-01-01

    Borderline personality disorder (BPD) is being increasingly recognized by clinicians working with adolescents, and the reliability and validity of the diagnosis have been established in the adolescent population. Adolescence is known to be a period of high risk for BPD development as most patients identify the onset of their symptoms to be in the adolescent period. As with other mental health disorders, personality disorder, are thought to result from the interaction between biological and environmental factors. Functional neuroimaging studies are reporting an increasing amount of data on abnormal neuronal functions in BPD adult patients. However, no functional neuroimaging studies have been conducted in adolescents with BPD.Objectives This pilot project aims to evaluate the feasibility of a functional magnetic resonance imaging (fMRI) study coupled with clinical and psychological measures in adolescent girls with a diagnosis of BPD. It also aims to identify neuronal regions of interest (ROI) for the study of BPD in adolescent girls.Method Six female adolescents meeting DSM-IV criteria for BPD and 6 female adolescents without psychiatric disorder were recruited. Both groups were evaluated for BPD symptoms, depressive symptoms, impulsivity, affective lability, and other potential psychiatric comorbidities. We used fMRI to compare patterns of regional brain activation between these two groups as they viewed 20 positive, 20 negative and 20 neutral emotion-inducing pictures, which were presented in random order.Results Participants were recruited over a period of 22 months. The protocol was well tolerated by participants. Mean age of the BPD group and control group was 15.8 ± 0.9 years-old and 15.5 ± 1.2 years-old respectively. Psychiatric comorbidity and use of medication was common among participants in the BPD group. This group showed higher impulsivity and affective lability scores. For the fMRI task, BPD patients demonstrated greater differences in activation

  1. Neuroimaging Findings in Cryptogenic Stroke Patients with and without PFO

    PubMed Central

    Thaler, David E.; Ruthazer, Robin; Di Angelantonio, Emanuele; Di Tullio, Marco R.; Donovan, Jennifer S.; Elkind, Mitchell S. V.; Griffith, John; Homma, Shunichi; Jaigobin, Cheryl; Mas, Jean-Louis; Mattle, Heinrich P.; Michel, Patrik; Mono, Marie-Luise; Nedeltchev, Krassen; Papetti, Federica; Serena, Joaquín; Weimar, Christian; Kent, David M.

    2013-01-01

    BACKGROUND Patent foramen ovale (PFO) and cryptogenic stroke (CS) are commonly associated but some PFOs are incidental. Specific radiological findings associated with PFO may be more likely to indicate a PFO-related etiology. We examined whether specific radiological findings are associated with PFO among subjects with CS and known PFO status. METHODS We analyzed the Risk of Paradoxical Embolism (RoPE) database of subjects with CS and known PFO status, for associations between PFO and: 1) index stroke seen on imaging, 2) index stroke size, 3) index stroke location, 4) multiple index strokes, and 5) prior stroke on baseline imaging. We also compared imaging with purported “high risk” echocardiographic features. RESULTS Subjects (n=2680) were significantly more likely to have a PFO if their index stroke was large (OR 1.36, p=0.0025), seen on index imaging (OR 1.53, p=0.003), and superficially located (OR 1.54, p<0.0001). A prior stroke on baseline imaging was associated with not having a PFO (OR 0.66, p<0.0001). Finding multiple index strokes was unrelated to PFO status (OR 1.21, p=0.161). No echocardiographic variables were related to PFO status. CONCLUSIONS This is the largest study to report the radiological characteristics of patients with CS and known PFO status. Strokes that were large, radiologically apparent, superficially located, or unassociated with prior radiological infarcts were more likely to be PFO associated than were unapparent, smaller, or deep strokes, and those accompanied by chronic infarcts. There was no association between PFO and multiple acute strokes nor between specific echocardiographic PFO features with neuroimaging findings. PMID:23339957

  2. Neuroimaging in Alzheimer's disease: preclinical challenges toward clinical efficacy.

    PubMed

    Dustin, Derek; Hall, Benjamin M; Annapragada, Ananth; Pautler, Robia G

    2016-09-01

    The scope of this review focuses on recent applications in preclinical and clinical magnetic resonance imaging (MRI) toward accomplishing the goals of early detection and responses to therapy in animal models of Alzheimer's disease (AD). Driven by the outstanding efforts of the Alzheimer's Disease Neuroimaging Initiative (ADNI), a truly invaluable resource, the initial use of MRI in AD imaging has been to assess changes in brain anatomy, specifically assessing brain shrinkage and regional changes in white matter tractography using diffusion tensor imaging. However, advances in MRI have led to multiple efforts toward imaging amyloid beta plaques first without and then with the use of MRI contrast agents. These technological advancements have met with limited success and are not yet appropriate for the clinic. Recent developments in molecular imaging inclusive of high-power liposomal-based MRI contrast agents as well as fluorine 19 ((19)F) MRI and manganese enhanced MRI have begun to propel promising advances toward not only plaque imaging but also using MRI to detect perturbations in subcellular processes occurring within the neuron. This review concludes with a discussion about the necessity for the development of novel preclinical models of AD that better recapitulate human AD for the imaging to truly be meaningful and for substantive progress to be made toward understanding and effectively treating AD. Furthermore, the continued support of outstanding programs such as ADNI as well as the development of novel molecular imaging agents and MRI fast scanning sequences will also be requisite to effectively translate preclinical findings to the clinic. PMID:27033146

  3. Multiple Sclerosis in Malaysia: Demographics, Clinical Features, and Neuroimaging Characteristics

    PubMed Central

    Viswanathan, S.; Rose, N.; Masita, A.; Dhaliwal, J. S.; Puvanarajah, S. D.; Rafia, M. H.; Muda, S.

    2013-01-01

    Background. Multiple sclerosis (MS) is an uncommon disease in multiracial Malaysia. Diagnosing patients with idiopathic inflammatory demyelinating diseases has been greatly aided by the evolution in diagnostic criterion, the identification of new biomarkers, and improved accessibility to neuroimaging in the country. Objectives. To investigate the spectrum of multiple sclerosis in Malaysia. Methods. Retrospective analysis with longitudinal follow-up of patients referred to a single tertiary medical center with neurology services in Malaysia. Results. Out of 245 patients with idiopathic inflammatory demyelinating disease, 104 patients had multiple sclerosis. Female to male ratio was 5 : 1. Mean age at onset was 28.6 ± 9.9 years. The Malays were the predominant racial group affected followed by the Chinese, Indians, and other indigenous groups. Subgroup analysis revealed more Chinese having neuromyelitis optica and its spectrum disorders rather than multiple sclerosis. Positive family history was reported in 5%. Optic neuritis and myelitis were the commonest presentations at onset of disease, and relapsing remitting course was the commonest disease pattern observed. Oligoclonal band positivity was 57.6%. At disease onset, 61.5% and 66.4% fulfilled the 2005 and 2010 McDonald's criteria for dissemination in space. Mean cord lesion length was 1.86 ± 1.65 vertebral segments in the relapsing remitting group as opposed to 6.25 ± 5.18 vertebral segments in patients with neuromyelitis optica and its spectrum disorders. Conclusion. The spectrum of multiple sclerosis in Malaysia has changed over the years. Further advancement in diagnostic criteria will no doubt continue to contribute to the evolution of this disease here. PMID:24455266

  4. DeID - a data sharing tool for neuroimaging studies.

    PubMed

    Song, Xuebo; Wang, James; Wang, Anlin; Meng, Qingping; Prescott, Christian; Tsu, Loretta; Eckert, Mark A

    2015-01-01

    Funding institutions and researchers increasingly expect that data will be shared to increase scientific integrity and provide other scientists with the opportunity to use the data with novel methods that may advance understanding in a particular field of study. In practice, sharing human subject data can be complicated because data must be de-identified prior to sharing. Moreover, integrating varied data types collected in a study can be challenging and time consuming. For example, sharing data from structural imaging studies of a complex disorder requires the integration of imaging, demographic and/or behavioral data in a way that no subject identifiers are included in the de-identified dataset and with new subject labels or identification values that cannot be tracked back to the original ones. We have developed a Java program that users can use to remove identifying information in neuroimaging datasets, while still maintaining the association among different data types from the same subject for further studies. This software provides a series of user interaction wizards to allow users to select data variables to be de-identified, implements functions for auditing and validation of de-identified data, and enables the user to share the de-identified data in a single compressed package through various communication protocols, such as FTPS and SFTP. DeID runs with Windows, Linux, and Mac operating systems and its open architecture allows it to be easily adapted to support a broader array of data types, with the goal of facilitating data sharing. DeID can be obtained at http://www.nitrc.org/projects/deid. PMID:26441500

  5. The child with a cephalocele: etiology, neuroimaging, and outcome.

    PubMed

    Martínez-Lage, J F; Poza, M; Sola, J; Soler, C L; Montalvo, C G; Domingo, R; Puche, A; Ramón, F H; Azorín, P; Lasso, R

    1996-09-01

    We report a series of 46 children who were treated for one of the diverse forms of cranium bifidum during a period of 22 years. The purpose of the survey was to investigate pathogenetic factors involved in the development of cranial dysraphism and to analyze clinical and pathological factors that influence the patients' outcome. We also investigated the existence of associated intracranial anomalies, in a systematic way, using modern methods of neuroimaging, and related the findings to the patients' final results. The lesions were classified as encephalocele (n = 15), cranial meningocele (n = 3), atretic cephalocele (n = 26), cranium bifidum occultum (n = 1), and exencephaly (n = 1). There was an excess of the atretic form of cephaloceles in our series, a fact that probably reflects geographical variations described for cephaloceles in general. The location of the lesions was occipital in 29 children, parietal in 16, and temporal and frontobasal in one case each. In seven cases there was parental consanguinity. A familial history of malformations of the central nervous system was encountered in eight instances. Associated systemic abnormalities were present in 23 patients, while central nervous system anomalies were found in 36 children. Cephalocele repair was undertaken on 35 occasions. There were no surgical fatalities in the series. The mean follow-up time was of 7 years. Overall mortality for the whole group was of 17/46 or 36%. Twenty of the 29 survivors had no neurological sequelae, but only 18 children exhibited a competitive intelligence level. A good outcome was found to correlate well with: an average head size at birth, a normal initial neurological condition, operability of the lesions, and an absence of disorders of the neuronal migration. Neurological outcome depended also on the occurrence or not of hydrocephalus, while the intelligence level was mainly related to the absence of cerebral tissue within the sac of the malformation. PMID:8906370

  6. Multiple sclerosis in malaysia: demographics, clinical features, and neuroimaging characteristics.

    PubMed

    Viswanathan, S; Rose, N; Masita, A; Dhaliwal, J S; Puvanarajah, S D; Rafia, M H; Muda, S

    2013-01-01

    Background. Multiple sclerosis (MS) is an uncommon disease in multiracial Malaysia. Diagnosing patients with idiopathic inflammatory demyelinating diseases has been greatly aided by the evolution in diagnostic criterion, the identification of new biomarkers, and improved accessibility to neuroimaging in the country. Objectives. To investigate the spectrum of multiple sclerosis in Malaysia. Methods. Retrospective analysis with longitudinal follow-up of patients referred to a single tertiary medical center with neurology services in Malaysia. Results. Out of 245 patients with idiopathic inflammatory demyelinating disease, 104 patients had multiple sclerosis. Female to male ratio was 5 : 1. Mean age at onset was 28.6 ± 9.9 years. The Malays were the predominant racial group affected followed by the Chinese, Indians, and other indigenous groups. Subgroup analysis revealed more Chinese having neuromyelitis optica and its spectrum disorders rather than multiple sclerosis. Positive family history was reported in 5%. Optic neuritis and myelitis were the commonest presentations at onset of disease, and relapsing remitting course was the commonest disease pattern observed. Oligoclonal band positivity was 57.6%. At disease onset, 61.5% and 66.4% fulfilled the 2005 and 2010 McDonald's criteria for dissemination in space. Mean cord lesion length was 1.86 ± 1.65 vertebral segments in the relapsing remitting group as opposed to 6.25 ± 5.18 vertebral segments in patients with neuromyelitis optica and its spectrum disorders. Conclusion. The spectrum of multiple sclerosis in Malaysia has changed over the years. Further advancement in diagnostic criteria will no doubt continue to contribute to the evolution of this disease here. PMID:24455266

  7. Neuroimaging with magnetoencephalography: A dynamic view of brain pathophysiology.

    PubMed

    Wilson, Tony W; Heinrichs-Graham, Elizabeth; Proskovec, Amy L; McDermott, Timothy J

    2016-09-01

    Magnetoencephalography (MEG) is a noninvasive, silent, and totally passive neurophysiological imaging method with excellent temporal resolution (∼1 ms) and good spatial precision (∼3-5 mm). In a typical experiment, MEG data are acquired as healthy controls or patients with neurologic or psychiatric disorders perform a specific cognitive task, or receive sensory stimulation. The resulting data are generally analyzed using standard electrophysiological methods, coupled with advanced image reconstruction algorithms. To date, the total number of MEG instruments and associated users is significantly smaller than comparable human neuroimaging techniques, although this is likely to change in the near future with advances in the technology. Despite this small base, MEG research has made a significant impact on several areas of translational neuroscience, largely through its unique capacity to quantify the oscillatory dynamics of activated brain circuits in humans. This review focuses on the clinical areas where MEG imaging has arguably had the greatest impact in regard to the identification of aberrant neural dynamics at the regional and network level, monitoring of disease progression, determining how efficacious pharmacologic and behavioral interventions modulate neural systems, and the development of neural markers of disease. Specifically, this review covers recent advances in understanding the abnormal neural oscillatory dynamics that underlie Parkinson's disease, autism spectrum disorders, human immunodeficiency virus (HIV)-associated neurocognitive disorders, cerebral palsy, attention-deficit hyperactivity disorder, cognitive aging, and post-traumatic stress disorder. MEG imaging has had a major impact on how clinical neuroscientists understand the brain basis of these disorders, and its translational influence is rapidly expanding with new discoveries and applications emerging continuously. PMID:26874219

  8. Functional and molecular neuroimaging of menopause and hormone replacement therapy

    PubMed Central

    Comasco, Erika; Frokjaer, Vibe G.; Sundström-Poromaa, Inger

    2014-01-01

    The level of gonadal hormones to which the female brain is exposed considerably changes across the menopausal transition, which in turn, is likely to be of great relevance for neurodegenerative diseases and psychiatric disorders. However, the neurobiological consequences of these hormone fluctuations and of hormone replacement therapy in the menopause have only begun to be understood. The present review summarizes the findings of thirty-five studies of human brain function, including functional magnetic resonance imaging, positron and single-photon computed emission tomography studies, in peri- and postmenopausal women treated with estrogen, or estrogen-progestagen replacement therapy. Seven studies using gonadotropin-releasing hormone agonist intervention as a model of hormonal withdrawal are also included. Cognitive paradigms are employed by the majority of studies evaluating the effect of unopposed estrogen or estrogen-progestagen treatment on peri- and postmenopausal women's brain. In randomized-controlled trials, estrogen treatment enhances activation of fronto-cingulate regions during cognitive functioning, though in many cases no difference in cognitive performance was present. Progestagens seems to counteract the effects of estrogens. Findings on cognitive functioning during acute ovarian hormone withdrawal suggest a decrease in activation of the left inferior frontal gyrus, thus essentially corroborating the findings in postmenopausal women. Studies of the cholinergic and serotonergic systems indicate these systems as biological mediators of hormonal influences on the brain. More, hormonal replacement appears to increase cerebral blood flow in several cortical regions. On the other hand, studies on emotion processing in postmenopausal women are lacking. These results call for well-powered randomized-controlled multi-modal prospective neuroimaging studies as well as investigation on the related molecular mechanisms of effects of menopausal hormonal

  9. Nipype: A Flexible, Lightweight and Extensible Neuroimaging Data Processing Framework in Python

    PubMed Central

    Gorgolewski, Krzysztof; Burns, Christopher D.; Madison, Cindee; Clark, Dav; Halchenko, Yaroslav O.; Waskom, Michael L.; Ghosh, Satrajit S.

    2011-01-01

    Current neuroimaging software offer users an incredible opportunity to analyze their data in different ways, with different underlying assumptions. Several sophisticated software packages (e.g., AFNI, BrainVoyager, FSL, FreeSurfer, Nipy, R, SPM) are used to process and analyze large and often diverse (highly multi-dimensional) data. However, this heterogeneous collection of specialized applications creates several issues that hinder replicable, efficient, and optimal use of neuroimaging analysis approaches: (1) No uniform access to neuroimaging analysis software and usage information; (2) No framework for comparative algorithm development and dissemination; (3) Personnel turnover in laboratories often limits methodological continuity and training new personnel takes time; (4) Neuroimaging software packages do not address computational efficiency; and (5) Methods sections in journal articles are inadequate for reproducing results. To address these issues, we present Nipype (Neuroimaging in Python: Pipelines and Interfaces; http://nipy.org/nipype), an open-source, community-developed, software package, and scriptable library. Nipype solves the issues by providing Interfaces to existing neuroimaging software with uniform usage semantics and by facilitating interaction between these packages using Workflows. Nipype provides an environment that encourages interactive exploration of algorithms, eases the design of Workflows within and between packages, allows rapid comparative development of algorithms and reduces the learning curve necessary to use different packages. Nipype supports both local and remote execution on multi-core machines and clusters, without additional scripting. Nipype is Berkeley Software Distribution licensed, allowing anyone unrestricted usage. An open, community-driven development philosophy allows the software to quickly adapt and address the varied needs of the evolving neuroimaging community, especially in the context of increasing demand for

  10. Understanding Actions of Others: The Electrodynamics of the Left and Right Hemispheres. A High-Density EEG Neuroimaging Study

    PubMed Central

    Ortigue, Stephanie; Sinigaglia, Corrado; Rizzolatti, Giacomo; Grafton, Scott T.

    2010-01-01

    Background When we observe an individual performing a motor act (e.g. grasping a cup) we get two types of information on the basis of how the motor act is done and the context: what the agent is doing (i.e. grasping) and the intention underlying it (i.e. grasping for drinking). Here we examined the temporal dynamics of the brain activations that follow the observation of a motor act and underlie the observer's capacity to understand what the agent is doing and why. Methodology/Principal Findings Volunteers were presented with two-frame video-clips. The first frame (T0) showed an object with or without context; the second frame (T1) showed a hand interacting with the object. The volunteers were instructed to understand the intention of the observed actions while their brain activity was recorded with a high-density 128-channel EEG system. Visual event-related potentials (VEPs) were recorded time-locked with the frame showing the hand-object interaction (T1). The data were analyzed by using electrical neuroimaging, which combines a cluster analysis performed on the group-averaged VEPs with the localization of the cortical sources that give rise to different spatio-temporal states of the global electrical field. Electrical neuroimaging results revealed four major steps: 1) bilateral posterior cortical activations; 2) a strong activation of the left posterior temporal and inferior parietal cortices with almost a complete disappearance of activations in the right hemisphere; 3) a significant increase of the activations of the right temporo-parietal region with simultaneously co-active left hemispheric sources, and 4) a significant global decrease of cortical activity accompanied by the appearance of activation of the orbito-frontal cortex. Conclusions/Significance We conclude that the early striking left hemisphere involvement is due to the activation of a lateralized action-observation/action execution network. The activation of this lateralized network mediates the

  11. Multiple tasks and neuroimaging modalities increase the likelihood of detecting covert awareness in patients with disorders of consciousness.

    PubMed

    Gibson, Raechelle M; Fernández-Espejo, Davinia; Gonzalez-Lara, Laura E; Kwan, Benjamin Y; Lee, Donald H; Owen, Adrian M; Cruse, Damian

    2014-01-01

    Minimal or inconsistent behavioral responses to command make it challenging to accurately diagnose the level of awareness of a patient with a Disorder of consciousness (DOC). By identifying markers of mental imagery being covertly performed to command, functional neuroimaging (fMRI), electroencephalography (EEG) has shown that some of these patients are aware despite their lack of behavioral responsiveness. We report the findings of behavioral, fMRI, and EEG approaches to detecting command-following in a group of patients with DOC. From an initial sample of 14 patients, complete data across all tasks was obtained in six cases. Behavioral evaluations were performed with the Coma Recovery Scale-Revised. Both fMRI and EEG evaluations involved the completion of previously validated mental imagery tasks-i.e., motor imagery (EEG and fMRI) and spatial navigation imagery (fMRI). One patient exhibited statistically significant evidence of motor imagery in both the fMRI and EEG tasks, despite being unable to follow commands behaviorally. Two behaviorally non-responsive patients produced appropriate activation during the spatial navigation fMRI task. However, neither of these patients successfully completed the motor imagery tasks, likely due to specific motor area damage in at least one of these cases. A further patient demonstrated command following only in the EEG motor imagery task, and two patients did not demonstrate command following in any of the behavioral, EEG, or fMRI assessments. Due to the heterogeneity of etiology and pathology in this group, DOC patients vary in terms of their suitability for some forms of neuroimaging, the preservation of specific neural structures, and the cognitive resources that may be available to them. Assessments of a range of cognitive abilities supported by spatially-distinct brain regions and indexed by multiple neural signatures are therefore required in order to accurately characterize a patient's level of residual cognition and

  12. Integration of a neuroimaging processing pipeline into a pan-canadian computing grid

    NASA Astrophysics Data System (ADS)

    Lavoie-Courchesne, S.; Rioux, P.; Chouinard-Decorte, F.; Sherif, T.; Rousseau, M.-E.; Das, S.; Adalat, R.; Doyon, J.; Craddock, C.; Margulies, D.; Chu, C.; Lyttelton, O.; Evans, A. C.; Bellec, P.

    2012-02-01

    The ethos of the neuroimaging field is quickly moving towards the open sharing of resources, including both imaging databases and processing tools. As a neuroimaging database represents a large volume of datasets and as neuroimaging processing pipelines are composed of heterogeneous, computationally intensive tools, such open sharing raises specific computational challenges. This motivates the design of novel dedicated computing infrastructures. This paper describes an interface between PSOM, a code-oriented pipeline development framework, and CBRAIN, a web-oriented platform for grid computing. This interface was used to integrate a PSOM-compliant pipeline for preprocessing of structural and functional magnetic resonance imaging into CBRAIN. We further tested the capacity of our infrastructure to handle a real large-scale project. A neuroimaging database including close to 1000 subjects was preprocessed using our interface and publicly released to help the participants of the ADHD-200 international competition. This successful experiment demonstrated that our integrated grid-computing platform is a powerful solution for high-throughput pipeline analysis in the field of neuroimaging.

  13. Neurobiological narratives: experiences of mood disorder through the lens of neuroimaging.

    PubMed

    Buchman, Daniel Z; Borgelt, Emily L; Whiteley, Louise; Illes, Judy

    2013-01-01

    Many scientists, healthcare providers, policymakers and patients are awaiting in anticipation the application of biomedical technologies such as functional neuroimaging for the prediction, diagnosis and treatment of mental disorders. The potential efficacy of such applications is controversial, and functional neuroimaging is not yet routinely used in psychiatric clinics. However, commercial ventures and enthusiastic reporting indicate a pressing need to engage with the social and ethical issues raised by clinical translation. There has been little investigation of how individuals living with mental illness view functional neuroimaging, or of the potential psychological impacts of its clinical use. We conducted 12 semi-structured interviews with adults diagnosed with major depression or bipolar disorder, probing their experiences with mental health care and their perspectives on the prospect of receiving neuroimaging for prediction, diagnosis and planning treatment. The participants discussed the potential role of neuroimages in (i) mitigating stigma; (ii) supporting morally loaded explanations of mental illness due to an imbalance of brain chemistry; (iii) legitimising psychiatric symptoms, which may have previously been de-legitimised since they lacked objective representation, through objective representations of disorder; and (iv) reifying DSM-IV-TR disorder categories and links to identity. We discuss these anticipated outcomes in the context of participant lived experience and attitudes to biologisation of mental illness, and argue for bringing these voices into upstream ethics discussion. PMID:22554090

  14. ABrIL - Advanced Brain Imaging Lab : a cloud based computation environment for cooperative neuroimaging projects.

    PubMed

    Neves Tafula, Sérgio M; Moreira da Silva, Nádia; Rozanski, Verena E; Silva Cunha, João Paulo

    2014-01-01

    Neuroscience is an increasingly multidisciplinary and highly cooperative field where neuroimaging plays an important role. Neuroimaging rapid evolution is demanding for a growing number of computing resources and skills that need to be put in place at every lab. Typically each group tries to setup their own servers and workstations to support their neuroimaging needs, having to learn from Operating System management to specific neuroscience software tools details before any results can be obtained from each setup. This setup and learning process is replicated in every lab, even if a strong collaboration among several groups is going on. In this paper we present a new cloud service model - Brain Imaging Application as a Service (BiAaaS) - and one of its implementation - Advanced Brain Imaging Lab (ABrIL) - in the form of an ubiquitous virtual desktop remote infrastructure that offers a set of neuroimaging computational services in an interactive neuroscientist-friendly graphical user interface (GUI). This remote desktop has been used for several multi-institution cooperative projects with different neuroscience objectives that already achieved important results, such as the contribution to a high impact paper published in the January issue of the Neuroimage journal. The ABrIL system has shown its applicability in several neuroscience projects with a relatively low-cost, promoting truly collaborative actions and speeding up project results and their clinical applicability. PMID:25570014

  15. Relationships between cognitive performance, neuroimaging, and vascular disease: the DHS-Mind Study

    PubMed Central

    Hsu, Fang-Chi; Raffield, Laura M.; Hugenschmidt, Christina E.; Cox, Amanda; Xu, Jianzhao; Carr, J. Jeffery; Freedman, Barry I.; Maldjian, Joseph A.; Williamson, Jeff D.; Bowden, Donald W.

    2015-01-01

    Background Type 2 diabetes mellitus increases risk for cognitive decline and dementia; elevated burdens of vascular disease are hypothesized to contribute to this risk. These relationships were examined in the Diabetes Heart Study-Mind using a battery of cognitive tests, neuroimaging measures, and subclinical cardiovascular disease (CVD) burden assessed by coronary artery calcified plaque (CAC). We hypothesized that CAC would attenuate the association between neuroimaging measures and cognition performance. Methods Associations were examined using marginal models in this family-based cohort of 572 European Americans from 263 families. All models were adjusted for age, gender, education, type 2 diabetes, and hypertension, with some neuroimaging measures additionally adjusted for intracranial volume. Results Higher total brain volume (TBV) was associated with better performance on the Digit Symbol Substitution Task (DSST) and Semantic Fluency (both p≤7.0 x 10−4). Higher gray matter volume (GMV) was associated with better performance on the Modified Mini-Mental State Examination and Semantic Fluency (both p≤9.0 x 10−4). Adjusting for CAC caused minimal changes to the results. Conclusions Relationships exist between neuroimaging measures and cognitive performance in a type 2 diabetes-enriched European American cohort. Associations were minimally attenuated after adjusting for subclinical CVD. Additional work is needed to understand how subclinical CVD burden interacts with other factors and impacts relationships between neuroimaging and cognitive testing measures. PMID:26185004

  16. Reading the Freudian theory of sexual drives from a functional neuroimaging perspective

    PubMed Central

    Stoléru, Serge

    2014-01-01

    One of the essential tasks of neuropsychoanalysis is to investigate the neural correlates of sexual drives. Here, we consider the four defining characteristics of sexual drives as delineated by Freud: their pressure, aim, object, and source. We systematically examine the relations between these characteristics and the four-component neurophenomenological model that we have proposed based on functional neuroimaging studies, which comprises a cognitive, a motivational, an emotional and an autonomic/neuroendocrine component. Functional neuroimaging studies of sexual arousal (SA) have thrown a new light on the four fundamental characteristics of sexual drives by identifying their potential neural correlates. While these studies are essentially consistent with the Freudian model of drives, the main difference emerging between the functional neuroimaging perspective on sexual drives and the Freudian theory relates to the source of drives. From a functional neuroimaging perspective, sources of sexual drives, conceived by psychoanalysis as processes of excitation occurring in a peripheral organ, do not seem, at least in adult subjects, to be an essential part of the determinants of SA. It is rather the central processing of visual or genital stimuli that gives to these stimuli their sexually arousing and sexually pleasurable character. Finally, based on functional neuroimaging results, some possible improvements to the psychoanalytic theory of sexual drives are suggested. PMID:24672467

  17. A clinical case study of a psychoanalytic psychotherapy monitored with functional neuroimaging

    PubMed Central

    Buchheim, Anna; Labek, Karin; Walter, Steffen; Viviani, Roberto

    2013-01-01

    This case study describes 1 year of the psychoanalytic psychotherapy using clinical data, a standardized instrument of the psychotherapeutic process (Psychotherapy process Q-Set, PQS), and functional neuroimaging (fMRI). A female dysthymic patient with narcissistic traits was assessed at monthly intervals (12 sessions). In the fMRI scans, which took place immediately after therapy hours, the patient looked at pictures of attachment-relevant scenes (from the Adult Attachment Projective Picture System, AAP) divided into two groups: those accompanied by a neutral description, and those accompanied by a description tailored to core conflicts of the patient as assessed in the AAP. Clinically, this patient presented defense mechanisms that influenced the relationship with the therapist and that was characterized by fluctuations of mood that lasted whole days, following a pattern that remained stable during the year of the study. The two modes of functioning associated with the mood shifts strongly affected the interaction with the therapist, whose quality varied accordingly (“easy” and “difficult” hours). The PQS analysis showed the association of “easy” hours with the topic of the involvement in significant relationships and of “difficult hours” with self-distancing, a defensive maneuver common in narcissistic personality structures. In the fMRI data, the modes of functioning visible in the therapy hours were significantly associated with modulation of the signal elicited by personalized attachment-related scenes in the posterior cingulate (p = 0.017 cluster-level, whole-volume corrected). This region has been associated in previous studies to self-distancing from negatively valenced pictures presented during the scan. The present study may provide evidence of the possible involvement of this brain area in spontaneously enacted self-distancing defensive strategies, which may be of relevance in resistant reactions in the course of a psychoanalytic

  18. A clinical case study of a psychoanalytic psychotherapy monitored with functional neuroimaging.

    PubMed

    Buchheim, Anna; Labek, Karin; Walter, Steffen; Viviani, Roberto

    2013-01-01

    This case study describes 1 year of the psychoanalytic psychotherapy using clinical data, a standardized instrument of the psychotherapeutic process (Psychotherapy process Q-Set, PQS), and functional neuroimaging (fMRI). A female dysthymic patient with narcissistic traits was assessed at monthly intervals (12 sessions). In the fMRI scans, which took place immediately after therapy hours, the patient looked at pictures of attachment-relevant scenes (from the Adult Attachment Projective Picture System, AAP) divided into two groups: those accompanied by a neutral description, and those accompanied by a description tailored to core conflicts of the patient as assessed in the AAP. Clinically, this patient presented defense mechanisms that influenced the relationship with the therapist and that was characterized by fluctuations of mood that lasted whole days, following a pattern that remained stable during the year of the study. The two modes of functioning associated with the mood shifts strongly affected the interaction with the therapist, whose quality varied accordingly ("easy" and "difficult" hours). The PQS analysis showed the association of "easy" hours with the topic of the involvement in significant relationships and of "difficult hours" with self-distancing, a defensive maneuver common in narcissistic personality structures. In the fMRI data, the modes of functioning visible in the therapy hours were significantly associated with modulation of the signal elicited by personalized attachment-related scenes in the posterior cingulate (p = 0.017 cluster-level, whole-volume corrected). This region has been associated in previous studies to self-distancing from negatively valenced pictures presented during the scan. The present study may provide evidence of the possible involvement of this brain area in spontaneously enacted self-distancing defensive strategies, which may be of relevance in resistant reactions in the course of a psychoanalytic psychotherapy. PMID

  19. PET Neuroimaging: Insights on Dystonia and Tourette Syndrome and Potential Applications

    PubMed Central

    Alongi, Pierpaolo; Iaccarino, Leonardo; Perani, Daniela

    2014-01-01

    Primary dystonia (pD) is a movement disorder characterized by sustained or intermittent muscle contractions causing abnormal, often repetitive, movements, postures, or both. Gilles de la Tourette syndrome (GTS) is a childhood-onset neuropsychiatric developmental disorder characterized by motor and phonic tics, which could progress to behavioral changes. GTS and obsessive–compulsive disorders are often seen in comorbidity, also suggesting that a possible overlap in the pathophysiological bases of these two conditions. PET techniques are of considerable value in detecting functional and molecular abnormalities in vivo, according to the adopted radioligands. For example, PET is the unique technique that allows in vivo investigation of neurotransmitter systems, providing evidence of changes in GTS or pD. For example, presynaptic and post-synaptic dopaminergic studies with PET have shown alterations compatible with dysfunction or loss of D2-receptors bearing neurons, increased synaptic dopamine levels, or both. Measures of cerebral glucose metabolism with 18F-fluorodeoxyglucose PET (18F-FDG PET) are very sensitive in showing brain functional alterations as well. 18F-FDG PET data have shown metabolic changes within the cortico-striato-pallido-thalamo-cortical and cerebello-thalamo-cortical networks, revealing possible involvement of brain circuits not limited to basal ganglia in pD and GTS. The aim of this work is to overview PET consistent neuroimaging literature on pD and GTS that has provided functional and molecular knowledge of the underlying neural dysfunction. Furthermore, we suggest potential applications of these techniques in monitoring treatments. PMID:25295029

  20. Vulnerability of Welders to Manganese Exposure – A Neuroimaging Study

    PubMed Central

    Zaiyang, Long; Yue-Ming, Jiang; Xiang-Rong, Li; William, Fadel; Jun, Xu; Chien-Lin, Yeh; Li-Ling, Long; Hai-Lan, Luo; Jaroslaw, Harezlak; James B, Murdoch; Wei, Zheng; Ulrike, Dydak

    2014-01-01

    Increased manganese (Mn) exposure is known to cause cognitive, psychiatric and motor deficits. Mn exposure occurs in different occupational settings, where the airborne Mn level and the size of respirable particulates may vary considerably. Recently the importance of the role of the cerebral cortex in Mn toxicity has been highlighted, especially in Mn-induced neuropsychological effects. In this study we used magnetic resonance imaging (MRI) to evaluate brain Mn accumulation using T1 signal intensity indices and to examine changes in brain iron content using T2* contrast, as well as magnetic resonance spectroscopy (MRS) to measure exposure-induced metabolite changes non-invasively in cortical and deep brain regions in Mn-exposed welders, Mn-exposed smelter workers and control factory workers with no measurable exposure to Mn. MRS data as well as T1 signal intensity indices and T2* values were acquired from the frontal cortex, posterior cingulate cortex, hippocampus, and thalamus. Smelters were exposed to higher air Mn levels and had a longer duration of exposure, which was reflected in higher Mn levels in erythrocytes and urine than in welders. Nonetheless, welders had more significant metabolic differences compared to controls than did the smelter workers, especially in the frontal cortex. T1 hyperintensities in the globus pallidus were observed in both Mn-exposed groups, but only welders showed significantly higher thalamic and hippocampal T1 hyperintensities, as well as significantly reduced T2* values in the frontal cortex. Our results indicate that (1) the cerebral cortex, in particular the frontal cortex, is clearly involved in Mn neurotoxic effects and (2) in spite of the lower air Mn levels and shorter duration of exposure, welders exhibit more extensive neuroimaging changes compared to controls than smelters, including measurable deposition of Mn in more brain areas. These results indicate that the type of exposure (particulate sizes, dust versus fume) and

  1. Vulnerability of welders to manganese exposure--a neuroimaging study.

    PubMed

    Long, Zaiyang; Jiang, Yue-Ming; Li, Xiang-Rong; Fadel, William; Xu, Jun; Yeh, Chien-Lin; Long, Li-Ling; Luo, Hai-Lan; Harezlak, Jaroslaw; Murdoch, James B; Zheng, Wei; Dydak, Ulrike

    2014-12-01

    Increased manganese (Mn) exposure is known to cause cognitive, psychiatric and motor deficits. Mn exposure occurs in different occupational settings, where the airborne Mn level and the size of respirable particulates may vary considerably. Recently the importance of the role of the cerebral cortex in Mn toxicity has been highlighted, especially in Mn-induced neuropsychological effects. In this study we used magnetic resonance imaging (MRI) to evaluate brain Mn accumulation using T1 signal intensity indices and to examine changes in brain iron content using T2* contrast, as well as magnetic resonance spectroscopy (MRS) to measure exposure-induced metabolite changes non-invasively in cortical and deep brain regions in Mn-exposed welders, Mn-exposed smelter workers and control factory workers with no measurable exposure to Mn. MRS data as well as T1 signal intensity indices and T2* values were acquired from the frontal cortex, posterior cingulate cortex, hippocampus, and thalamus. Smelters were exposed to higher air Mn levels and had a longer duration of exposure, which was reflected in higher Mn levels in erythrocytes and urine than in welders. Nonetheless, welders had more significant metabolic differences compared to controls than did the smelter workers, especially in the frontal cortex. T1 hyperintensities in the globus pallidus were observed in both Mn-exposed groups, but only welders showed significantly higher thalamic and hippocampal T1 hyperintensities, as well as significantly reduced T2* values in the frontal cortex. Our results indicate that (1) the cerebral cortex, in particular the frontal cortex, is clearly involved in Mn neurotoxic effects and (2) in spite of the lower air Mn levels and shorter duration of exposure, welders exhibit more extensive neuroimaging changes compared to controls than smelters, including measurable deposition of Mn in more brain areas. These results indicate that the type of exposure (particulate sizes, dust versus fume) and

  2. Detecting Neuroimaging Biomarkers for Psychiatric Disorders: Sample Size Matters.

    PubMed

    Schnack, Hugo G; Kahn, René S

    2016-01-01

    In a recent review, it was suggested that much larger cohorts are needed to prove the diagnostic value of neuroimaging biomarkers in psychiatry. While within a sample, an increase of diagnostic accuracy of schizophrenia (SZ) with number of subjects (N) has been shown, the relationship between N and accuracy is completely different between studies. Using data from a recent meta-analysis of machine learning (ML) in imaging SZ, we found that while low-N studies can reach 90% and higher accuracy, above N/2 = 50 the maximum accuracy achieved steadily drops to below 70% for N/2 > 150. We investigate the role N plays in the wide variability in accuracy results in SZ studies (63-97%). We hypothesize that the underlying cause of the decrease in accuracy with increasing N is sample heterogeneity. While smaller studies more easily include a homogeneous group of subjects (strict inclusion criteria are easily met; subjects live close to study site), larger studies inevitably need to relax the criteria/recruit from large geographic areas. A SZ prediction model based on a heterogeneous group of patients with presumably a heterogeneous pattern of structural or functional brain changes will not be able to capture the whole variety of changes, thus being limited to patterns shared by most patients. In addition to heterogeneity (sample size), we investigate other factors influencing accuracy and introduce a ML effect size. We derive a simple model of how the different factors, such as sample heterogeneity and study setup determine this ML effect size, and explain the variation in prediction accuracies found from the literature, both in cross-validation and independent sample testing. From this, we argue that smaller-N studies may reach high prediction accuracy at the cost of lower generalizability to other samples. Higher-N studies, on the other hand, will have more generalization power, but at the cost of lower accuracy. In conclusion, when comparing results from different

  3. Detecting Neuroimaging Biomarkers for Psychiatric Disorders: Sample Size Matters

    PubMed Central

    Schnack, Hugo G.; Kahn, René S.

    2016-01-01

    In a recent review, it was suggested that much larger cohorts are needed to prove the diagnostic value of neuroimaging biomarkers in psychiatry. While within a sample, an increase of diagnostic accuracy of schizophrenia (SZ) with number of subjects (N) has been shown, the relationship between N and accuracy is completely different between studies. Using data from a recent meta-analysis of machine learning (ML) in imaging SZ, we found that while low-N studies can reach 90% and higher accuracy, above N/2 = 50 the maximum accuracy achieved steadily drops to below 70% for N/2 > 150. We investigate the role N plays in the wide variability in accuracy results in SZ studies (63–97%). We hypothesize that the underlying cause of the decrease in accuracy with increasing N is sample heterogeneity. While smaller studies more easily include a homogeneous group of subjects (strict inclusion criteria are easily met; subjects live close to study site), larger studies inevitably need to relax the criteria/recruit from large geographic areas. A SZ prediction model based on a heterogeneous group of patients with presumably a heterogeneous pattern of structural or functional brain changes will not be able to capture the whole variety of changes, thus being limited to patterns shared by most patients. In addition to heterogeneity (sample size), we investigate other factors influencing accuracy and introduce a ML effect size. We derive a simple model of how the different factors, such as sample heterogeneity and study setup determine this ML effect size, and explain the variation in prediction accuracies found from the literature, both in cross-validation and independent sample testing. From this, we argue that smaller-N studies may reach high prediction accuracy at the cost of lower generalizability to other samples. Higher-N studies, on the other hand, will have more generalization power, but at the cost of lower accuracy. In conclusion, when comparing results from different

  4. Multi-Parametric Neuroimaging Reproducibility: A 3T Resource Study

    PubMed Central

    Landman, Bennett A.; Huang, Alan J.; Gifford, Aliya; Vikram, Deepti S.; Lim, Issel Anne L.; Farrell, Jonathan A.D.; Bogovic, John A.; Hua, Jun; Chen, Min; Jarso, Samson; Smith, Seth A.; Joel, Suresh; Mori, Susumu; Pekar, James J.; Barker, Peter B.; Prince, Jerry L.; van Zijl, Peter C.M.

    2010-01-01

    richness of the joint distribution of intensities across imaging methods can be best assessed within the context of a particular analysis approach as opposed to a summary table. As such, all imaging data and analysis routines have been made publicly and freely available. This effort provides the neuroimaging community with a resource for optimization of algorithms that exploit the diversity of modern MRI modalities. Additionally, it establishes a baseline for continuing development and optimization of multi-parametric imaging protocols. PMID:21094686

  5. Order Information in Working Memory: An Integrative Review of Evidence From Brain and Behavior

    ERIC Educational Resources Information Center

    Marshuetz, Christy

    2005-01-01

    Evidence about memory for order information comes from a number of different methodologies: human cognition, patient studies, neuroimaging studies, and animal lesion and behavioral studies. The present article discusses (a) evidence that order and item memory are separable; (b) proposed mechanisms for order memory (interitem associations, direct…

  6. Brain Morphometry and the Neurobiology of Levodopa-Induced Dyskinesias: Current Knowledge and Future Potential for Translational Pre-Clinical Neuroimaging Studies

    PubMed Central

    Finlay, Clare J.; Duty, Susan; Vernon, Anthony C.

    2014-01-01

    Dopamine replacement therapy in the form of levodopa results in a significant proportion of patients with Parkinson’s disease developing debilitating dyskinesia. This significantly complicates further treatment and negatively impacts patient quality of life. A greater understanding of the neurobiological mechanisms underlying levodopa-induced dyskinesia (LID) is therefore crucial to develop new treatments to prevent or mitigate LID. Such investigations in humans are largely confined to assessment of neurochemical and cerebrovascular blood flow changes using positron emission tomography and functional magnetic resonance imaging. However, recent evidence suggests that LID is associated with specific morphological changes in the frontal cortex and midbrain, detectable by structural MRI and voxel-based morphometry. Current human neuroimaging methods however lack sufficient resolution to reveal the biological mechanism driving these morphological changes at the cellular level. In contrast, there is a wealth of literature from well-established rodent models of LID documenting detailed post-mortem cellular and molecular measurements. The combination therefore of advanced neuroimaging methods and rodent LID models offers an exciting opportunity to bridge these currently disparate areas of research. To highlight this opportunity, in this mini-review, we provide an overview of the current clinical evidence for morphological changes in the brain associated with LID and identify potential cellular mechanisms as suggested from human and animal studies. We then suggest a framework for combining small animal MRI imaging with rodent models of LID, which may provide important mechanistic insights into the neurobiology of LID. PMID:24971074

  7. Clinical use of amyloid-positron emission tomography neuroimaging: Practical and bioethical considerations.

    PubMed

    Witte, Michael M; Foster, Norman L; Fleisher, Adam S; Williams, Monique M; Quaid, Kimberly; Wasserman, Michael; Hunt, Gail; Roberts, J Scott; Rabinovici, Gil D; Levenson, James L; Hake, Ann Marie; Hunter, Craig A; Van Campen, Luann E; Pontecorvo, Michael J; Hochstetler, Helen M; Tabas, Linda B; Trzepacz, Paula T

    2015-09-01

    Until recently, estimation of β-amyloid plaque density as a key element for identifying Alzheimer's disease (AD) pathology as the cause of cognitive impairment was only possible at autopsy. Now with amyloid-positron emission tomography (amyloid-PET) neuroimaging, this AD hallmark can be detected antemortem. Practitioners and patients need to better understand potential diagnostic benefits and limitations of amyloid-PET and the complex practical, ethical, and social implications surrounding this new technology. To complement the practical considerations, Eli Lilly and Company sponsored a Bioethics Advisory Board to discuss ethical issues that might arise from clinical use of amyloid-PET neuroimaging with patients being evaluated for causes of cognitive decline. To best address the multifaceted issues associated with amyloid-PET neuroimaging, we recommend this technology be used only by experienced imaging and treating physicians in appropriately selected patients and only in the context of a comprehensive clinical evaluation with adequate explanations before and after the scan. PMID:27239516

  8. Neuroimaging and Genetic Risk for Alzheimer’s Disease and Addiction-Related Degenerative Brain Disorders

    PubMed Central

    Jahanshad, Neda; Leonardo, Cassandra D.; Thompson, Paul M.

    2014-01-01

    Neuroimaging offers a powerful means to assess the trajectory of brain degeneration in a variety of disorders, including Alzheimer’s disease (AD). Here we describe how multimodal imaging can be used to study the changing brain during the different stages of AD. We integrate findings from a range of studies using magnetic resonance imaging (MRI), positron emission tomography (PET), functional MRI (fMRI) and diffusion weighted imaging (DWI). Neuroimaging reveals how risk genes for degenerative disorders affect the brain, including several recently discovered genetic variants that may disrupt brain connectivity. We review some recent neuroimaging studies of genetic polymorphisms associated with increased risk for late-onset Alzheimer’s disease (LOAD). Some genetic variants that increase risk for drug addiction may overlap with those associated with degenerative brain disorders. These common associations offer new insight into mechanisms underlying neurodegeneration and addictive behaviors, and may offer new leads for treating them before severe and irreversible neurological symptoms appear. PMID:24142306

  9. Mind-Body Practices and the Adolescent Brain: Clinical Neuroimaging Studies

    PubMed Central

    Sharma, Anup; Newberg, Andrew B

    2016-01-01

    Background Mind-Body practices constitute a large and diverse group of practices that can substantially affect neurophysiology in both healthy individuals and those with various psychiatric disorders. In spite of the growing literature on the clinical and physiological effects of mind-body practices, very little is known about their impact on central nervous system (CNS) structure and function in adolescents with psychiatric disorders. Method This overview highlights findings in a select group of mind-body practices including yoga postures, yoga breathing techniques and meditation practices. Results Mind-body practices offer novel therapeutic approaches for adolescents with psychiatric disorders. Findings from these studies provide insights into the design and implementation of neuroimaging studies for adolescents with psychiatric disorders. Conclusions Clinical neuroimaging studies will be critical in understanding how different practices affect disease pathogenesis and symptomatology in adolescents. Neuroimaging of mind-body practices on adolescents with psychiatric disorders will certainly be an open and exciting area of investigation. PMID:27347478

  10. Functional neuroimaging: a brief overview and feasibility for use in chiropractic research

    PubMed Central

    Lystad, Reidar P; Pollard, Henry

    2009-01-01

    There is a need to further our understanding of the neurophysiological effects of chiropractic spinal manipulation on brain activity as it pertains to both musculoskeletal and non-musculoskeletal complaints. This paper aims to provide a basic overview of the most commonly utilised techniques in the neurosciences for functional imaging the brain (positron emission tomography, single-photon emission computerised tomography, functional magnetic resonance imaging, electroencephalography, and magnetoencephalography), and discuss their applicability in future chiropractic research. Functional neuroimaging modalities are used in a wide range of different research and clinical settings, and are powerful tools in the investigation of neuronal activity in the human brain. There are many potential applications for functional neuroimaging in future chiropractic research, but there are some feasibility issues, mainly pertaining to access and funding. We strongly encourage the use of functional neuroimaging in future investigations of the effects of chiropractic spinal manipulation on brain function. PMID:19421353

  11. The BrainMap strategy for standardization, sharing, and meta-analysis of neuroimaging data

    PubMed Central

    2011-01-01

    Background Neuroimaging researchers have developed rigorous community data and metadata standards that encourage meta-analysis as a method for establishing robust and meaningful convergence of knowledge of human brain structure and function. Capitalizing on these standards, the BrainMap project offers databases, software applications, and other associated tools for supporting and promoting quantitative coordinate-based meta-analysis of the structural and functional neuroimaging literature. Findings In this report, we describe recent technical updates to the project and provide an educational description for performing meta-analyses in the BrainMap environment. Conclusions The BrainMap project will continue to evolve in response to the meta-analytic needs of biomedical researchers in the structural and functional neuroimaging communities. Future work on the BrainMap project regarding software and hardware advances are also discussed. PMID:21906305

  12. Functional and clinical insights from neuroimaging studies in childhood-onset schizophrenia.

    PubMed

    Ordóñez, Anna E; Sastry, Nevin V; Gogtay, Nitin

    2015-08-01

    Childhood-onset schizophrenia is a rare pediatric onset psychiatric disorder continuous with and typically more severe than its adult counterpart. Neuroimaging research conducted on this population has revealed similarly severe neural abnormalities. When taken as a whole, neuroimaging research in this population shows generally decreased cortical gray matter coupled with white matter connectivity abnormalities, suggesting an anatomical basis for deficits in executive function. Subcortical abnormalities are pronounced in limbic structures, where volumetric deficits are likely related to social skill deficits, and cerebellar deficits that have been correlated to cognitive abnormalities. Structures relevant to motor processing also show a significant alteration, with volumetric increase in basal ganglia structures likely due to antipsychotic administration. Neuroimaging of this disorder shows an important clinical image of exaggerated cortical loss, altered white matter connectivity, and differences in structural development of subcortical areas during the course of development and provides important background to the disease state. PMID:26234702

  13. Cognitive Control of Language Production in Bilinguals Involves a Partly Independent Process within the Domain-General Cognitive Control Network: Evidence from Task-switching and Electrical Brain Activity

    ERIC Educational Resources Information Center

    Magezi, David A.; Khateb, Asaid; Mouthon, Michael; Spierer, Lucas; Annoni, Jean-Marie

    2012-01-01

    In highly proficient, early bilinguals, behavioural studies of the cost of switching language or task suggest qualitative differences between language control and domain-general cognitive control. By contrast, several neuroimaging studies have shown an overlap of the brain areas involved in language control and domain-general cognitive control.…

  14. An expanded role for neuroimaging in the evaluation of memory impairment

    PubMed Central

    Desikan, Rahul S.; Rafii, Michael S.; Brewer, James B.; Hess, Christopher P.

    2014-01-01

    Alzheimer’s disease (AD) affects millions of people worldwide. The neuropathologic process underlying AD begins years, if not decades, before the onset of memory decline. Recent advances in neuroimaging suggest that it is now possible to detect AD-associated neuropathological changes well before dementia onset. Here, we evaluate the role of recently developed in vivo biomarkers in the clinical evaluation of AD. We discuss how assessment strategies might incorporate neuroimaging markers to better inform patients, families and clinicians when memory impairment prompts a search for diagnosis and management options. PMID:23764728

  15. Inferring mental states from neuroimaging data: From reverse inference to large-scale decoding

    PubMed Central

    Poldrack, Russell A.

    2011-01-01

    A common goal of neuroimaging research is to use imaging data to identify the mental processes that are engaged when a subject performs a mental task. The use of reasoning from activation to mental functions, known as “reverse inference”, has been previously criticized on the basis that it does not take into account how selectively the area is activated by the mental process in question. In this Perspective, I outline the critique of informal reverse inference, and describe a number of new developments that provide the ability to more formally test the predictive power of neuroimaging data. PMID:22153367

  16. Predictors of diagnostic neuroimaging delays among adults presenting with symptoms suggestive of acute stroke in Ontario: a prospective cohort study

    PubMed Central

    Burton, Kirsteen R.; Kapral, Moira K.; Li, Shudong; Fang, Jiming; Moody, Alan R.; Krahn, Murray; Laupacis, Andreas

    2016-01-01

    Background: Many studies have examined the timeliness of thrombolysis for acute ischemic stroke, but less is known about door-to-imaging time. We conducted a prospective cohort study to assess the timing of neuroimaging among patients with suspected acute stroke in the province of Ontario, Canada, and to examine factors associated with delays in neuroimaging. Methods: We included all patients 18 years and older with suspected acute stroke seen at hospitals with neuroimaging capacity within the Ontario Stroke Registry between Apr. 1, 2010, and Mar. 31, 2011. We used a hierarchical, multivariable Cox proportional hazards model to evaluate the association between patient and hospital factors and the likelihood of receiving timely neuroimaging (≤ 25 min) after arrival in the emergency department. Results: A total of 13 250 patients presented to an emergency department with stroke-like symptoms during the study period. Of the 3984 who arrived within 4 hours after symptom onset, 1087 (27.3%) had timely neuroimaging. The factors independently associated with an increased likelihood of timely neuroimaging were less time from symptom onset to presentation, more severe stroke, male sex, no history of stroke or transient ischemic attack, arrival to hospital from a setting other than home and presentation to a designated stroke centre or an urban hospital. Interpretation: A minority of patients with stroke-like symptoms who presented within the 4-hour thrombolytic treatment window received timely neuroimaging. Neuroimaging delays were influenced by various patient and hospital factors, some of which are modifiable. PMID:27398382

  17. Current Practice in the Referral of Individuals with Suspected Dementia for Neuroimaging by General Practitioners in Ireland and Wales

    PubMed Central

    Ciblis, Aurelia S.; Butler, Marie-Louise; Quinn, Catherine; Clare, Linda; Bokde, Arun L. W.; Mullins, Paul G.; McNulty, Jonathan P.

    2016-01-01

    Objectives While early diagnosis of dementia is important, the question arises whether general practitioners (GPs) should engage in direct referrals. The current study investigated current referral practices for neuroimaging in dementia, access to imaging modalities and investigated related GP training in Ireland and North Wales. Methods A questionnaire was distributed to GPs in the programme regions which included approximately two thirds of all GPs in the Republic of Ireland and all general practitioners in North Wales. A total of 2,093 questionnaires were issued. Results 48.6% of Irish respondents and 24.3% of Welsh respondents directly referred patients with suspected dementia for neuroimaging. Irish GPs reported greater direct access to neuroimaging than their Welsh counterparts. A very small percentage of Irish and Welsh GPs (4.7% and 10% respectively) had received training in neuroimaging and the majority who referred patients for neuroimaging were not aware of any dementia-specific protocols for referrals (93.1% and 95% respectively). Conclusions The benefits of direct GP access to neuroimaging investigations for dementia have yet to be established. Our findings suggest that current GP speciality training in Ireland and Wales is deficient in dementia-specific and neuroimaging training with the concern being that inadequate training will lead to inadequate referrals. Further training would complement guidelines and provide a greater understanding of the role and appropriateness of neuroimaging techniques in the diagnosis of dementia. PMID:27007435