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Sample records for abnormal neural responses

  1. [Tilt test and orthostatic intolerance: abnormalities in the neural sympathetic response to gravitational stimulus].

    PubMed

    Furlan, R

    2001-05-01

    In the present manuscript the different methodologies aimed at assessing the autonomic profile in humans during a gravitational stimulus have been described. In addition, strengths and drawbacks of the tilt test in relation to occasional orthostatic intolerance were addressed. Finally, different autonomic abnormalities underlying occasional and chronic orthostatic intolerance syndromes have been schematically highlighted. The direct recording of the neural sympathetic discharge from the peroneal nerve (MSNA), in spite of its invasive nature, still represents the recognized reference to quantify the changes in the sympathetic activity to the vessels attending postural modifications. The increase of plasma norepinephrine during a tilt test is achieved by both an increase in plasma spillover and a concomitant decrease in systemic clearance. Changes in the indices of cardiac sympathetic and vagal modulation may also be quantified during a tilt test by power spectrum analysis of RR interval variability. The spectral markers of cardiac autonomic control, if evaluated concomitantly with MSNA, may contribute to assess abnormalities in the regional distribution of the sympathetic activity to the heart and the vessels. The capability of the tilt test of reproducing a vasovagal event or of inducing "false positive responses" seems to be markedly affected by the age, thus suggesting that additional or different etiopathogenetic mechanisms might be involved in the loss of consciousness in older as compared to younger subjects. In subjects suffering from occasional or habitual neurally mediated syncope an increase or, respectively, a decrease in cardiac and vascular sympathetic modulation has been documented before the loss of consciousness. In patients with pure autonomic failure, a global dysautonomia affecting both the sympathetic and the vagal modulation to the heart, seems to be present. In chronic orthostatic intolerance, the most common form of dysautonomia of young women

  2. Abnormal relationships between the neural response to high- and low-calorie foods and endogenous acylated ghrelin in women with active and weight-recovered anorexia nervosa

    PubMed Central

    Holsen, Laura M.; Lawson, Elizabeth A.; Christensen, Kara; Klibanski, Anne; Goldstein, Jill M.

    2014-01-01

    Evidence contributing to the understanding of neurobiological mechanisms underlying appetite dysregulation in anorexia nervosa draws heavily on separate lines of research into neuroendocrine and neural circuitry functioning. In particular, studies consistently cite elevated ghrelin and abnormal activation patterns in homeostatic (hypothalamus) and hedonic (striatum, amygdala, insula) regions governing appetite. The current preliminary study examined the interaction of these systems, based on research demonstrating associations between circulating ghrelin levels and activity in these regions in healthy individuals. In a cross-sectional design, we studied 13 women with active anorexia nervosa (AN), 9 women weight-recovered from AN (AN-WR), and 12 healthy-weight control women using a food cue functional magnetic resonance imaging paradigm, with assessment of fasting levels of acylated ghrelin. Healthy-weight control women exhibited significant positive associations between fasting acylated ghrelin and activity in the right amygdala, hippocampus, insula, and orbitofrontal cortex in response to high-calorie foods, associations which were absent in the AN and AN-WR groups. Women with AN-WR demonstrated a negative relationship between ghrelin and activity in the left hippocampus in response to high-calorie foods, while women with AN showed a positive association between ghrelin and activity in the right orbitofrontal cortex in response to low-calorie foods. Findings suggest a breakdown in the interaction between ghrelin signaling and neural activity in relation to reward responsivity in AN, a phenomenon that may be further characterized using pharmacogenetic studies. PMID:24862390

  3. Abnormal folate metabolism in foetuses affected by neural tube defects.

    PubMed

    Dunlevy, Louisa P E; Chitty, Lyn S; Burren, Katie A; Doudney, Kit; Stojilkovic-Mikic, Taita; Stanier, Philip; Scott, Rosemary; Copp, Andrew J; Greene, Nicholas D E

    2007-04-01

    Folic acid supplementation can prevent many cases of neural tube defects (NTDs), whereas suboptimal maternal folate status is a risk factor, suggesting that folate metabolism is a key determinant of susceptibility to NTDs. Despite extensive genetic analysis of folate cycle enzymes, and quantification of metabolites in maternal blood, neither the protective mechanism nor the relationship between maternal folate status and susceptibility are understood in most cases. In order to investigate potential abnormalities in folate metabolism in the embryo itself, we derived primary fibroblastic cell lines from foetuses affected by NTDs and subjected them to the dU suppression test, a sensitive metabolic test of folate metabolism. Significantly, a subset of NTD cases exhibited low scores in this test, indicative of abnormalities in folate cycling that may be causally linked to the defect. Susceptibility to NTDs may be increased by suppression of the methylation cycle, which is interlinked with the folate cycle. However, reduced efficacy in the dU suppression test was not associated with altered abundance of the methylation cycle intermediates, s-adenosylmethionine and s-adenosylhomocysteine, suggesting that a methylation cycle defect is unlikely to be responsible for the observed abnormality of folate metabolism. Genotyping of samples for known polymorphisms in genes encoding folate-associated enzymes did not reveal any correlation between specific genotypes and the observed abnormalities in folate metabolism. These data suggest that as yet unrecognized genetic variants result in embryonic abnormalities of folate cycling that may be causally related to NTDs.

  4. Classification of breast abnormalities using artificial neural network

    NASA Astrophysics Data System (ADS)

    Zaman, Nur Atiqah Kamarul; Rahman, Wan Eny Zarina Wan Abdul; Jumaat, Abdul Kadir; Yasiran, Siti Salmah

    2015-05-01

    Classification is the process of recognition, differentiation and categorizing objects into groups. Breast abnormalities are calcifications which are tumor markers that indicate the presence of cancer in the breast. The aims of this research are to classify the types of breast abnormalities using artificial neural network (ANN) classifier and to evaluate the accuracy performance using receiver operating characteristics (ROC) curve. The methods used in this research are ANN for breast abnormalities classifications and Canny edge detector as a feature extraction method. Previously the ANN classifier provides only the number of benign and malignant cases without providing information for specific cases. However in this research, the type of abnormality for each image can be obtained. The existing MIAS MiniMammographic database classified the mammogram images into three features only namely characteristic of background tissues, class of abnormality and radius of abnormality. However, in this research three other features are added-in. These three features are number of spots, area and shape of abnormalities. Lastly the performance of the ANN classifier is evaluated using ROC curve. It is found that ANN has an accuracy of 97.9% which is considered acceptable.

  5. Neural correlates of abnormal sensory discrimination in laryngeal dystonia.

    PubMed

    Termsarasab, Pichet; Ramdhani, Ritesh A; Battistella, Giovanni; Rubien-Thomas, Estee; Choy, Melissa; Farwell, Ian M; Velickovic, Miodrag; Blitzer, Andrew; Frucht, Steven J; Reilly, Richard B; Hutchinson, Michael; Ozelius, Laurie J; Simonyan, Kristina

    2016-01-01

    Aberrant sensory processing plays a fundamental role in the pathophysiology of dystonia; however, its underpinning neural mechanisms in relation to dystonia phenotype and genotype remain unclear. We examined temporal and spatial discrimination thresholds in patients with isolated laryngeal form of dystonia (LD), who exhibited different clinical phenotypes (adductor vs. abductor forms) and potentially different genotypes (sporadic vs. familial forms). We correlated our behavioral findings with the brain gray matter volume and functional activity during resting and symptomatic speech production. We found that temporal but not spatial discrimination was significantly altered across all forms of LD, with higher frequency of abnormalities seen in familial than sporadic patients. Common neural correlates of abnormal temporal discrimination across all forms were found with structural and functional changes in the middle frontal and primary somatosensory cortices. In addition, patients with familial LD had greater cerebellar involvement in processing of altered temporal discrimination, whereas sporadic LD patients had greater recruitment of the putamen and sensorimotor cortex. Based on the clinical phenotype, adductor form-specific correlations between abnormal discrimination and brain changes were found in the frontal cortex, whereas abductor form-specific correlations were observed in the cerebellum and putamen. Our behavioral and neuroimaging findings outline the relationship of abnormal sensory discrimination with the phenotype and genotype of isolated LD, suggesting the presence of potentially divergent pathophysiological pathways underlying different manifestations of this disorder.

  6. Chromosomal abnormalities in fetuses with ultrasonographically detected neural tube defects.

    PubMed

    Kanit, Hakan; Özkan, Azra Arici; Öner, Soner Recai; Ispahi, Ciğdem; Endrikat, Jan Siegfried; Ertan, Kubilay

    2011-10-01

    We analyzed the karyotype of fetuses with ultrasonographically detected neural tube defects (NTDs). In our study, we included a total of 194 fetuses with NTDs. We analyzed the type of NTD, the karyotype, maternal age, fetal gestational age at diagnosis, and fetal sex. Of the 194 fetuses with NTDs, 87 were anencephalic and 107 had other, nonanencephalic, NTDs. A total of 12 fetuses were shown to have chromosomal abnormalities. Three of 87 anencephalic fetuses (3.45%) had chromosomal abnormalities. The sex ratio for anencephalic fetuses was 65.5% : 34.5% for female and male fetuses. Nine of 107 fetuses with other NTDs (8.41%) had chromosomal abnormalities. Seven fetuses had isolated NTDs and a further seven fetuses had additional ultrasonographic anomalies. Two of the latter had abnormal karyotypes. The sex ratio of all other NTD cases was 67.3% : 32.7% for female and male fetuses. The high number of chromosomal abnormalities justifies prenatal karyotyping in all fetuses with ultrasonographically diagnosed NTDs.

  7. Identification of neural circuits underlying P300 abnormalities in schizophrenia

    PubMed Central

    O’Donnell, Brian F.; McCarley, Robert W.; Potts, Geoffrey F.; Salisbury, Dean F.; Nestor, Paul G.; Hirayasu, Yoshio; Niznikiewicz, Margaret A.; Barnard, John; Shen, Zi Jen; Weinstein, David M.; Bookstein, Fred L.; Shenton, Martha E.

    2010-01-01

    Event-related potentials (ERPs) provide a noninvasive method to evaluate neural activation and cognitive processes in schizophrenia. The pathophysiological significance of these findings would be greatly enhanced if scalp-recorded ERP abnormalities could be related to specific neural circuits and/or regions of the brain. Using quantitative approaches in which scalp-recorded ERP components are correlated with underlying neuroanatomy in schizophrenia, we focused on biophysical and statistical procedures (partial least squares) to relate the auditory P300 component to anatomic measures obtained from quantitative magnetic resonance imaging. These findings are consistent with other evidence that temporal lobe structures contribute to the generation of the scalp-recorded P300 component and that P300 amplitude asymmetry over temporal recording sites on the scalp may reflect anatomic asymmetries in the volume of the superior temporal gyrus in schizophrenia. PMID:10352563

  8. Spike history neural response model.

    PubMed

    Kameneva, Tatiana; Abramian, Miganoosh; Zarelli, Daniele; Nĕsić, Dragan; Burkitt, Anthony N; Meffin, Hamish; Grayden, David B

    2015-06-01

    There is a potential for improved efficacy of neural stimulation if stimulation levels can be modified dynamically based on the responses of neural tissue in real time. A neural model is developed that describes the response of neurons to electrical stimulation and that is suitable for feedback control neuroprosthetic stimulation. Experimental data from NZ white rabbit retinae is used with a data-driven technique to model neural dynamics. The linear-nonlinear approach is adapted to incorporate spike history and to predict the neural response of ganglion cells to electrical stimulation. To validate the fitness of the model, the penalty term is calculated based on the time difference between each simulated spike and the closest spike in time in the experimentally recorded train. The proposed model is able to robustly predict experimentally observed spike trains.

  9. Social anhedonia is associated with neural abnormalities during face emotion processing.

    PubMed

    Germine, Laura T; Garrido, Lucia; Bruce, Lori; Hooker, Christine

    2011-10-01

    Human beings are social organisms with an intrinsic desire to seek and participate in social interactions. Social anhedonia is a personality trait characterized by a reduced desire for social affiliation and reduced pleasure derived from interpersonal interactions. Abnormally high levels of social anhedonia prospectively predict the development of schizophrenia and contribute to poorer outcomes for schizophrenia patients. Despite the strong association between social anhedonia and schizophrenia, the neural mechanisms that underlie individual differences in social anhedonia have not been studied and are thus poorly understood. Deficits in face emotion recognition are related to poorer social outcomes in schizophrenia, and it has been suggested that face emotion recognition deficits may be a behavioral marker for schizophrenia liability. In the current study, we used functional magnetic resonance imaging (fMRI) to see whether there are differences in the brain networks underlying basic face emotion processing in a community sample of individuals low vs. high in social anhedonia. We isolated the neural mechanisms related to face emotion processing by comparing face emotion discrimination with four other baseline conditions (identity discrimination of emotional faces, identity discrimination of neutral faces, object discrimination, and pattern discrimination). Results showed a group (high/low social anhedonia) × condition (emotion discrimination/control condition) interaction in the anterior portion of the rostral medial prefrontal cortex, right superior temporal gyrus, and left somatosensory cortex. As predicted, high (relative to low) social anhedonia participants showed less neural activity in face emotion processing regions during emotion discrimination as compared to each control condition. The findings suggest that social anhedonia is associated with abnormalities in networks responsible for basic processes associated with social cognition, and provide a

  10. A neural model to study sensory abnormalities and multisensory effects in autism.

    PubMed

    Noriega, Gerardo

    2015-03-01

    Computational modeling plays an increasingly prominent role in complementing critical research in the genetics, neuroscience, and psychology of autism. This paper presents a model that supports the notion that weak central coherence, a processing bias for features and local information, may be responsible for perception abnormalities by failing to "control" sensory issues in autism. The model has a biologically plausible architecture based on a self-organizing map. It incorporates temporal information in input stimuli, with emphasis on real auditory signals, and provides a mechanism to model multisensory effects. Through comprehensive simulations the paper studies the effect of a control mechanism (akin to central coherence) in compensating the effects of temporal information in the presentation of stimuli, sensory abnormalities, and crosstalk between domains. The mechanism is successful in balancing out timing effects, basic hypersensitivities and, to a lesser degree, multisensory effects. An analysis of the effect of the control mechanism's onset time on performance suggests that most of the potential benefits are still attainable even when started rather late in the learning process. This high level of adaptability shown by the neural network highlights the importance of appropriate teaching and intervention throughout the lifetime of persons with autism and other neurological disorders.

  11. Failure of neural responses to safety cues in schizophrenia.

    PubMed

    Holt, Daphne J; Coombs, Garth; Zeidan, Mohamed A; Goff, Donald C; Milad, Mohammed R

    2012-09-01

    CONTEXT Abnormalities in associative memory processes, such as Pavlovian fear conditioning and extinction, have been observed in schizophrenia. The retrieval of fear extinction memories (safety signals) may be particularly affected; although schizophrenic patients can extinguish conditioned fear, they show a deficit in retrieving fear extinction memories after a delay. The neurobiological basis of this abnormality is unknown, but clues have emerged from studies in rodents and humans demonstrating that the ventromedial prefrontal cortex (vmPFC) is a key mediator of extinction memory retrieval. OBJECTIVE To measure autonomic and neural responses during the acquisition and extinction of conditioned fear and the delayed recall of fear and extinction memories in patients with schizophrenia and healthy control participants. DESIGN Cross-sectional case control, functional magnetic resonance imaging study. SETTING Academic medical center. PARTICIPANTS Twenty schizophrenic patients and 17 healthy control participants demographically matched to the patient group. MAIN OUTCOME MEASURES Skin conductance and blood oxygen level-dependent responses. RESULTS During fear conditioning, schizophrenic patients showed blunted autonomic responses and abnormal blood oxygen level-dependent responses, relative to control participants, within the posterior cingulate gyrus, hippocampus, and other regions. Several of these abnormalities were linked to negative symptoms. During extinction learning, patients with schizophrenia and control participants showed comparable autonomic and neural responses. Twenty-four hours after the learning phases, the control subjects exhibited decreased fear and increased vmPFC responses in the extinction (safe) context as expected, indicating successful retention of the extinction memory. In contrast, the schizophrenic patients showed inappropriately elevated fear and poor vmPFC responses in the safe context. CONCLUSION Failure of extinction memory retrieval in

  12. Pupillary response abnormalities in depressive disorders.

    PubMed

    Laurenzo, Scott A; Kardon, Randy; Ledolter, Johannes; Poolman, Pieter; Schumacher, Ashley M; Potash, James B; Full, Jan M; Rice, Olivia; Ketcham, Anna; Starkey, Cole; Fiedorowicz, Jess G

    2016-12-30

    Depressive disorders lack objective physiological measurements to characterize the affected population and facilitate study of relevant mechanisms. The melanopsin-mediated light signaling pathway may contribute to seasonal variation and can be measured non-invasively by pupillometry. We prospectively studied changes in melanopsin-mediated pupillary constriction in 19 participants with major depressive disorder (MDD) and 10 control across the summer and winter solstices. The melanopsin-mediated response, as measured by the pupil's sustained constriction six s after a high intensity blue light stimulus, was marginally attenuated in those with MDD relative to controls (p=0.071). The participants with MDD unexpectedly showed a significantly reduced transient pupillary response to low intensity red (p=0.011) and blue light (p=0.013), but not high intensity red and blue light. Sustained pupillary constriction in response to high intensity blue light was more pronounced with increasing daylight hours (p=0.037) and was more strongly related to objectively measured versus estimated light exposure. Melanopsin-mediated impairments in pupil response may serve as a biological marker for vulnerability to depression in low light conditions. Assessment of these and other responses to light stimuli, such as response to low intensity light, may be useful for the study of the neurobiology of MDD and related mood disorders.

  13. Differentiating neural reward responsiveness in autism versus ADHD.

    PubMed

    Kohls, Gregor; Thönessen, Heike; Bartley, Gregory K; Grossheinrich, Nicola; Fink, Gereon R; Herpertz-Dahlmann, Beate; Konrad, Kerstin

    2014-10-01

    Although attention deficit hyperactivity disorders (ADHD) and autism spectrum disorders (ASD) share certain neurocognitive characteristics, it has been hypothesized to differentiate the two disorders based on their brain's reward responsiveness to either social or monetary reward. Thus, the present fMRI study investigated neural activation in response to both reward types in age and IQ-matched boys with ADHD versus ASD relative to typically controls (TDC). A significant group by reward type interaction effect emerged in the ventral striatum with greater activation to monetary versus social reward only in TDC, whereas subjects with ADHD responded equally strong to both reward types, and subjects with ASD showed low striatal reactivity across both reward conditions. Moreover, disorder-specific neural abnormalities were revealed, including medial prefrontal hyperactivation in response to social reward in ADHD versus ventral striatal hypoactivation in response to monetary reward in ASD. Shared dysfunction was characterized by fronto-striato-parietal hypoactivation in both clinical groups when money was at stake. Interestingly, lower neural activation within parietal circuitry was associated with higher autistic traits across the entire study sample. In sum, the present findings concur with the assumption that both ASD and ADHD display distinct and shared neural dysfunction in response to reward.

  14. Abnormal O-GlcNAcylation of Pax3 Occurring from Hyperglycemia-Induced Neural Tube Defects Is Ameliorated by Carnosine But Not Folic Acid in Chicken Embryos.

    PubMed

    Tan, Rui-Rong; Li, Yi-Fang; Zhang, Shi-Jie; Huang, Wen-Shan; Tsoi, Bun; Hu, Dan; Wan, Xin; Yang, Xuesong; Wang, Qi; Kurihara, Hiroshi; He, Rong-Rong

    2017-01-01

    Neural tube defects (NTDs) are among the most common of the embryonic abnormalities associated with hyperglycemic gestation. In this study, the molecular mechanisms of embryonic neurogenesis influenced by hyperglycemia was investigated using chicken embryo models. High-concentration glucose was administered into chicken eggs and resulted in increased plasma and brain tissue glucose, and suppressed expression of glucose transporters (GLUTs). The rate of NTD positively correlated with hyperglycemia. Furthermore, abnormally increased O-GlcNAcylation, a nutritionally responsive modification, of the key neural tube marker Pax3 protein led to the loss of this protein. This loss was not observed in a folate-deficiency NTD induced by methotrexate. Carnosine, an endogenous dipeptide, showed significant recovery effects on neural tube development. In contrast, folic acid, a well-known periconceptional agent, surprisingly showed relatively minimal effect. Higher expression levels of the Pax3 protein were found in the carnosine-treated groups, while lower expression levels were found in folic acid groups. Furthermore, the abnormal O-GlcNAcylation of the Pax3 protein was restored by carnosine. These results suggest new insights into using endogenous nutrients for the protection of embryonic neurodevelopment affected by diabetes gestation. The abnormal excessive O-GlcNAcylation of Pax3 may be responsible for the neural tube defects associated with hyperglycemia.

  15. Abnormal Neural Activation to Faces in the Parents of Children with Autism.

    PubMed

    Yucel, G H; Belger, A; Bizzell, J; Parlier, M; Adolphs, R; Piven, J

    2015-12-01

    Parents of children with an autism spectrum disorder (ASD) show subtle deficits in aspects of social behavior and face processing, which resemble those seen in ASD, referred to as the "Broad Autism Phenotype " (BAP). While abnormal activation in ASD has been reported in several brain structures linked to social cognition, little is known regarding patterns in the BAP. We compared autism parents with control parents with no family history of ASD using 2 well-validated face-processing tasks. Results indicated increased activation in the autism parents to faces in the amygdala (AMY) and the fusiform gyrus (FG), 2 core face-processing regions. Exploratory analyses revealed hyper-activation of lateral occipital cortex (LOC) bilaterally in autism parents with aloof personality ("BAP+"). Findings suggest that abnormalities of the AMY and FG are related to underlying genetic liability for ASD, whereas abnormalities in the LOC and right FG are more specific to behavioral features of the BAP. Results extend our knowledge of neural circuitry underlying abnormal face processing beyond those previously reported in ASD to individuals with shared genetic liability for autism and a subset of genetically related individuals with the BAP.

  16. Adaptive neural control of aeroelastic response

    NASA Astrophysics Data System (ADS)

    Lichtenwalner, Peter F.; Little, Gerald R.; Scott, Robert C.

    1996-05-01

    The Adaptive Neural Control of Aeroelastic Response (ANCAR) program is a joint research and development effort conducted by McDonnell Douglas Aerospace (MDA) and the National Aeronautics and Space Administration, Langley Research Center (NASA LaRC) under a Memorandum of Agreement (MOA). The purpose of the MOA is to cooperatively develop the smart structure technologies necessary for alleviating undesirable vibration and aeroelastic response associated with highly flexible structures. Adaptive control can reduce aeroelastic response associated with buffet and atmospheric turbulence, it can increase flutter margins, and it may be able to reduce response associated with nonlinear phenomenon like limit cycle oscillations. By reducing vibration levels and loads, aircraft structures can have lower acquisition cost, reduced maintenance, and extended lifetimes. Phase I of the ANCAR program involved development and demonstration of a neural network-based semi-adaptive flutter suppression system which used a neural network for scheduling control laws as a function of Mach number and dynamic pressure. This controller was tested along with a robust fixed-gain control law in NASA's Transonic Dynamics Tunnel (TDT) utilizing the Benchmark Active Controls Testing (BACT) wing. During Phase II, a fully adaptive on-line learning neural network control system has been developed for flutter suppression which will be tested in 1996. This paper presents the results of Phase I testing as well as the development progress of Phase II.

  17. Neural activation during response competition

    NASA Technical Reports Server (NTRS)

    Hazeltine, E.; Poldrack, R.; Gabrieli, J. D.

    2000-01-01

    The flanker task, introduced by Eriksen and Eriksen [Eriksen, B. A., & Eriksen, C. W. (1974). Effects of noise letters upon the identification of a target letter in a nonsearch task. Perception & Psychophysics, 16, 143--149], provides a means to selectively manipulate the presence or absence of response competition while keeping other task demands constant. We measured brain activity using functional magnetic resonance imaging (fMRI) during performance of the flanker task. In accordance with previous behavioral studies, trials in which the flanking stimuli indicated a different response than the central stimulus were performed significantly more slowly than trials in which all the stimuli indicated the same response. This reaction time effect was accompanied by increases in activity in four regions: the right ventrolateral prefrontal cortex, the supplementary motor area, the left superior parietal lobe, and the left anterior parietal cortex. The increases were not due to changes in stimulus complexity or the need to overcome previously learned associations between stimuli and responses. Correspondences between this study and other experiments manipulating response interference suggest that the frontal foci may be related to response inhibition processes whereas the posterior foci may be related to the activation of representations of the inappropriate responses.

  18. Heterogeneity of neural mechanisms of response to pivotal response treatment

    PubMed Central

    Ventola, Pamela; Yang, Daniel Y. J.; Friedman, Hannah E.; Oosting, Devon; Wolf, Julie; Sukhodolsky, Denis G.; Pelphrey, Kevin A.

    2016-01-01

    We investigated the mechanisms by which Pivotal Response Treatment (PRT) improves social communication in a case series of 10 preschool-aged children with Autism Spectrum Disorder (ASD). Functional magnetic resonance imaging (fMRI) identified brain responses during a biological motion perception task conducted prior to and following 16 weeks of PRT treatment. Overall, the neural systems supporting social perception in these 10 children were malleable through implementation of PRT; following treatment, neural responses were more similar to those of typically developing children (TD). However, at baseline, half of the children exhibited hypoactivation, relative to a group of TD children, in the right posterior superior temporal sulcus (pSTS), and half exhibited hyperactivation in this region. Strikingly, the groups exhibited differential neural responses to treatment: The five children who exhibited hypoactivation at baseline evidenced increased activation in components of the reward system including the ventral striatum and putamen. The five children who exhibited hyperactivation at baseline evidenced decreased activation in subcortical regions critical for regulating the flow of stimulation and conveying signals of salience to the cortex—the thalamus, amygdala, and hippocampus. Our results support further investigation into the differential effects of particular treatment strategies relative to specific neural targets. Identification of treatment strategies that address the patterns of neural vulnerability unique to each patient is consistent with the priority of creating individually tailored interventions customized to the behavioral and neural characteristics of a given person. PMID:25370452

  19. Abnormal Population Responses in the Somatosensory Cortex of Alzheimer’s Disease Model Mice

    PubMed Central

    Maatuf, Yossi; Stern, Edward A.; Slovin, Hamutal

    2016-01-01

    Alzheimer’s disease (AD) is the most common form of dementia. One of the neuropathological hallmarks of AD is the accumulation of amyloid-β plaques. Overexpression of human amyloid precursor protein in transgenic mice induces hippocampal and neocortical amyloid-β accumulation and plaque deposition that increases with age. The impact of these effects on neuronal population responses and network activity in sensory cortex is not well understood. We used Voltage Sensitive Dye Imaging, to investigate at high spatial and temporal resolution, the sensory evoked population responses in the barrel cortex of aged transgenic (Tg) mice and of age-matched non-transgenic littermate controls (Ctrl) mice. We found that a whisker deflection evoked abnormal sensory responses in the barrel cortex of Tg mice. The response amplitude and the spatial spread of the cortical responses were significantly larger in Tg than in Ctrl mice. At the network level, spontaneous activity was less synchronized over cortical space than in Ctrl mice, however synchronization during evoked responses induced by whisker deflection did not differ between the two groups. Thus, the presence of elevated Aβ and plaques may alter population responses and disrupts neural synchronization in large-scale networks, leading to abnormalities in sensory processing. PMID:27079783

  20. Progressive Changes in a Distributed Neural Circuit Underlie Breathing Abnormalities in Mice Lacking MeCP2

    PubMed Central

    Huang, Teng-Wei; Kochukov, Mikhail Y.; Ward, Christopher S.; Merritt, Jonathan; Thomas, Kaitlin; Nguyen, Tiffani; Arenkiel, Benjamin R.

    2016-01-01

    Rett syndrome (RTT) is a neurodevelopmental disorder caused by mutations in Methyl-CpG-binding protein 2 (MECP2). Severe breathing abnormalities are common in RTT and are reproduced in mouse models of RTT. Previously, we found that removing MeCP2 from the brainstem and spinal cord in mice caused early lethality and abnormal breathing. To determine whether loss of MeCP2 in functional components of the respiratory network causes specific breathing disorders, we used the Cre/LoxP system to differentially manipulate MeCP2 expression throughout the brainstem respiratory network, specifically within HoxA4-derived tissues, which include breathing control circuitry within the nucleus tractus solitarius and the caudal part of ventral respiratory column but do not include more rostral parts of the breathing control circuitry. To determine whether respiratory phenotypes manifested in animals with MeCP2 removed from specific pons medullary respiratory circuits, we performed whole-body plethysmography and electrophysiological recordings from in vitro brainstem slices from mice lacking MeCP2 in different circuits. Our results indicate that MeCP2 expression in the medullary respiratory network is sufficient for normal respiratory rhythm and preventing apnea. However, MeCP2 expression within components of the breathing circuitry rostral to the HoxA4 domain are neither sufficient to prevent the hyperventilation nor abnormal hypoxic ventilatory response. Surprisingly, we found that MeCP2 expression in the HoxA4 domain alone is critical for survival. Our study reveals that MeCP2 is differentially required in select respiratory components for different aspects of respiratory functions, and collectively for the integrity of this network functions to maintain proper respiration. SIGNIFICANCE STATEMENT Breathing abnormalities are a significant clinical feature in Rett syndrome and are robustly reproduced in the mouse models of this disease. Previous work has established that alterations

  1. Controlling neural network responsiveness: tradeoffs and constraints

    PubMed Central

    Keren, Hanna; Marom, Shimon

    2014-01-01

    In recent years much effort is invested in means to control neural population responses at the whole brain level, within the context of developing advanced medical applications. The tradeoffs and constraints involved, however, remain elusive due to obvious complications entailed by studying whole brain dynamics. Here, we present effective control of response features (probability and latency) of cortical networks in vitro over many hours, and offer this approach as an experimental toy for studying controllability of neural networks in the wider context. Exercising this approach we show that enforcement of stable high activity rates by means of closed loop control may enhance alteration of underlying global input–output relations and activity dependent dispersion of neuronal pair-wise correlations across the network. PMID:24808860

  2. Abnormal responses to monetary outcomes in cortex, but not in the basal ganglia, in schizophrenia.

    PubMed

    Waltz, James A; Schweitzer, Julie B; Ross, Thomas J; Kurup, Pradeep K; Salmeron, Betty J; Rose, Emma J; Gold, James M; Stein, Elliot A

    2010-11-01

    Psychosis has been associated with aberrant brain activity concurrent with both the anticipation and integration of monetary outcomes. The extent to which abnormal reward-related neural signals can be observed in chronic, medicated patients with schizophrenia (SZ), however, is not clear. In an fMRI study involving 17 chronic outpatients with SZ and 17 matched controls, we used a monetary incentive delay (MID) task, in which different-colored shapes predicted gains, losses, or neutral outcomes. Subjects needed to respond to a target within a time window in order to receive the indicated gain or avoid the indicated loss. Group differences in blood-oxygen-level-dependent responses to cues and outcomes were assessed through voxel-wise whole-brain analyses and regions-of-interest analyses in the neostriatum and prefrontal cortex (PFC). Significant group by outcome valence interactions were observed in the medial and lateral PFC, lateral temporal cortex, and amygdalae, such that controls, but not patients, showed greater activation for gains, relative to losses. In the striatum, neural activity was modulated by outcome magnitude in both groups. Additionally, we found that ratings of negative symptoms in patients correlated with sensitivity to obtained losses in medial PFC, obtained gains in lateral PFC, and anticipated gains in left ventral striatum. Sensitivity to obtained gains in lateral PFC also correlated with positive symptom scores in patients. Our findings of systematic relationships between clinical symptoms and neural responses to stimuli associated with rewards and punishments offer promise that reward-related neural responses may provide sensitive probes of the effectiveness of treatments for negative symptoms.

  3. Exposure to traumatic experiences is associated with abnormal neural mechanism during charitable donation.

    PubMed

    Wei, Dongtao; Wang, Kangcheng; Shen, Yimo; Du, Xue; Li, Wenfu; Dupuis-Roy, Nicolas; Qiu, Jiang; Zhang, Qinglin

    2013-10-30

    Previous studies suggested that posttraumatic stress disorder (PTSD) might be associated with dysfunctional reward processing. At present, little is known about the neural mechanisms of reward-related processing during a charitable donation task in trauma survivors who do not go on to develop PTSD. We used functional magnetic resonance imaging (fMRI) to investigate the neural basis of charitable donation in non-PTSD survivors of the Sichuan earthquake. Results showed that activations in the striatum of trauma survivors were reduced in both the low donation (donated a small amount to the Red Cross) and the high donation conditions (donated a large amount to the Red Cross) compared with the healthy controls. Furthermore, the trauma survivors also exhibited less activity in the insula than the healthy controls in the high donation condition. These findings suggest that abnormal reward-related activations might be associated with dysfunctions in the reward pathway of trauma survivors. Also, we discuss the possibility that traumatic experiences attenuate the reactivity of reward-related brain areas to positive emotions (as induced by advantageous donations).

  4. Zika virus infection induces mitosis abnormalities and apoptotic cell death of human neural progenitor cells

    PubMed Central

    Souza, Bruno S. F.; Sampaio, Gabriela L. A.; Pereira, Ciro S.; Campos, Gubio S.; Sardi, Silvia I.; Freitas, Luiz A. R.; Figueira, Claudio P.; Paredes, Bruno D.; Nonaka, Carolina K. V.; Azevedo, Carine M.; Rocha, Vinicius P. C.; Bandeira, Antonio C.; Mendez-Otero, Rosalia; dos Santos, Ricardo Ribeiro; Soares, Milena B. P.

    2016-01-01

    Zika virus (ZIKV) infection has been associated with severe complications both in the developing and adult nervous system. To investigate the deleterious effects of ZIKV infection, we used human neural progenitor cells (NPC), derived from induced pluripotent stem cells (iPSC). We found that NPC are highly susceptible to ZIKV and the infection results in cell death. ZIKV infection led to a marked reduction in cell proliferation, ultrastructural alterations and induction of autophagy. Induction of apoptosis of Sox2+ cells was demonstrated by activation of caspases 3/7, 8 and 9, and by ultrastructural and flow cytometry analyses. ZIKV-induced death of Sox2+ cells was prevented by incubation with the pan-caspase inhibitor, Z-VAD-FMK. By confocal microscopy analysis we found an increased number of cells with supernumerary centrosomes. Live imaging showed a significant increase in mitosis abnormalities, including multipolar spindle, chromosome laggards, micronuclei and death of progeny after cell division. FISH analysis for chromosomes 12 and 17 showed increased frequency of aneuploidy, such as monosomy, trisomy and polyploidy. Our study reinforces the link between ZIKV and abnormalities in the developing human brain, including microcephaly. PMID:28008958

  5. Dissociable cortico-striatal connectivity abnormalities in major depression in response to monetary gains and penalties

    PubMed Central

    Admon, Roee; Nickerson, Lisa D.; Dillon, Daniel G.; Holmes, Avram J.; Bogdan, Ryan; Kumar, Poornima; Dougherty, Darin D.; Iosifescu, Dan V.; Mischoulon, David; Fava, Maurizio; Pizzagalli, Diego A.

    2014-01-01

    Background Individuals with major depressive disorder (MDD) are characterized by maladaptive responses to both positive and negative outcomes, which have been linked to localized abnormal activations in cortical and striatal brain regions. However, the exact neural circuitry implicated in such abnormalities remains largely unexplored. Methods In this study 26 unmedicated adults with MDD and 29 matched healthy controls completed a monetary incentive delay task during functional magnetic resonance imaging (fMRI). Psycho-physiological interaction (PPI) analyses probed group differences in connectivity separately in response to positive and negative outcomes (i.e., monetary gains and penalties). Results Relative to controls, MDD subjects displayed decreased connectivity between the caudate and dorsal anterior cingulate cortex (dACC) in response to monetary gains, yet increased connectivity between the caudate and a different, more rostral, dACC sub-region in response to monetary penalties. Moreover, exploratory analyses of 14 MDD patients who completed a 12-week, double-blind, placebo-controlled clinical trial after the baseline fMRI scans indicated that a more normative pattern of cortico-striatal connectivity pre-treatment was associated with more symptoms improvement 12 weeks later. Conclusions These results identify the caudate as a region with dissociable incentive-dependent dACC connectivity abnormalities in MDD, and provide initial evidence that cortico-striatal circuitry may play a role in MDD treatment response. Given the role of cortico-striatal circuitry in encoding action-outcome contingencies, such dysregulated connectivity may relate to the prominent disruptions in goal-directed behavior that characterize MDD. PMID:25055809

  6. Abnormal immune responses of Bloom's syndrome lymphocytes in vitro.

    PubMed Central

    Hütteroth, T H; Litwin, S D; German, J

    1975-01-01

    Bloom's syndrome is a rare autosmal recessive disorder, first characterized by growth retardation and asum-sensitive facial telangiectasia and more recently demonstarted to have increased chromosome instability, a predisposition to malignancy, and increased susecptibitily to infection. The present report ocncern the immune function of Bloom's syndrom lymphoctes in vitro. Four affected homozgotes and five heterozygotes were studied. An abnormal serum concentartion of at least one class of immunoglobin was present in three out of four homozgotes. Affected homozgotes were shown capable of both a humoral and cellular response after antigenic challenge, the responses in general being weak but detectable. Blood lymphocytes from Bloom's syndrome individuals were cultured in impaired proliferavite response and synthesized less immunoglobulin at the end of 5 days than did normal controls. In contrast, they had a normal proliferative response to phytohemagglutinin except at highest concentrations of the mitogen. In the mixed lymphocte culture, Bloom's syndrome lymphocytes proved to be poor responder cells but normal stimulator cells. Lmyphoctes from the heterozgotes produced normal responses in these three systems. Distrubed immunity appears to be on of several major consequences of homozygosity for the Bloom's syndrome gene. Although the explanation for this pleiotropism is at present obscure, the idea was advanced that the aberrant immune function is, along with the major clincial feature-small body size, amanifestation of defect in cellular proliferation. PMID:124745

  7. Neural responses to salient visual stimuli.

    PubMed Central

    Morris, J S; Friston, K J; Dolan, R J

    1997-01-01

    The neural mechanisms involved in the selective processing of salient or behaviourally important stimuli are uncertain. We used an aversive conditioning paradigm in human volunteer subjects to manipulate the salience of visual stimuli (emotionally expressive faces) presented during positron emission tomography (PET) neuroimaging. Increases in salience, and conflicts between the innate and acquired value of the stimuli, produced augmented activation of the pulvinar nucleus of the right thalamus. Furthermore, this pulvinar activity correlated positively with responses in structures hypothesized to mediate value in the brain right amygdala and basal forebrain (including the cholinergic nucleus basalis of Meynert). The results provide evidence that the pulvinar nucleus of the thalamus plays a crucial modulatory role in selective visual processing, and that changes in perceptual salience are mediated by value-dependent plasticity in pulvinar responses. PMID:9178546

  8. Fibromyalgia patients show an abnormal dopamine response to pain.

    PubMed

    Wood, Patrick B; Schweinhardt, Petra; Jaeger, Erik; Dagher, Alain; Hakyemez, Helene; Rabiner, Eugenii A; Bushnell, M Catherine; Chizh, Boris A

    2007-06-01

    Fibromyalgia is characterized by chronic widespread pain and bodily tenderness and is often accompanied by affective disturbances. Accumulating evidence indicates that fibromyalgia may involve a dysfunction of modulatory systems in the brain. While brain dopamine is best known for its role in pleasure, motivation and motor control, recent evidence suggests that it is also involved in pain modulation. Because dopamine is implicated in both pain modulation and affective processing, we hypothesized that fibromyalgia may involve a disturbance of dopaminergic neurotransmission. Fibromyalgia patients and matched healthy control subjects were subjected to deep muscle pain produced by injection of hypertonic saline into the anterior tibialis muscle. In order to determine the endogenous release of dopamine in response to painful stimulation, we used positron emission tomography to examine binding of [(11)C]-raclopride (D2/D3 ligand) in the brain during injection of painful hypertonic saline and nonpainful normal saline. Fibromyalgia patients experienced the hypertonic saline as more painful than healthy control subjects. Control subjects released dopamine in the basal ganglia during the painful stimulation, whereas fibromyalgia patients did not. In control subjects, the amount of dopamine release correlated with the amount of perceived pain but in fibromyalgia patients no such correlation was observed. These findings provide the first direct evidence that fibromyalgia patients have an abnormal dopamine response to pain. The disrupted dopaminergic reactivity in fibromyalgia patients could be a critical factor underlying the widespread pain and discomfort in fibromyalgia and suggests that the therapeutic effects of dopaminergic treatments for this intractable disorder should be explored.

  9. Directional abnormalities of vestibular and optokinetic responses in cerebellar disease

    NASA Technical Reports Server (NTRS)

    Walker, M. F.; Zee, D. S.; Shelhamer, M. J. (Principal Investigator)

    1999-01-01

    Directional abnormalities of vestibular and optokinetic responses in patients with cerebellar degeneration are reported. Three-axis magnetic search-coil recordings of the eye and head were performed in eight cerebellar patients. Among these patients, examples of directional cross-coupling were found during (1) high-frequency, high-acceleration head thrusts; (2) constant-velocity chair rotations with the head fixed; (3) constant-velocity optokinetic stimulation; and (4) following repetitive head shaking. Cross-coupling during horizontal head thrusts consisted of an inappropriate upward eye-velocity component. In some patients, sustained constant-velocity yaw-axis chair rotations produced a mixed horizontal-torsional nystagmus and/or an increase in the baseline vertical slow-phase velocity. Following horizontal head shaking, some patients showed an increase in the slow-phase velocity of their downbeat nystagmus. These various forms of cross-coupling did not necessarily occur to the same degree in a given patient; this suggests that different mechanisms may be responsible. It is suggested that cross-coupling during head thrusts may reflect a loss of calibration of brainstem connections involved in the direct vestibular pathways, perhaps due to dysfunction of the flocculus. Cross-coupling during constant-velocity rotations and following head shaking may result from a misorientation of the angular eye-velocity vector in the velocity-storage system. Finally, responses to horizontal optokinetic stimulation included an inappropriate torsional component in some patients. This suggests that the underlying organization of horizontal optokinetic tracking is in labyrinthine coordinates. The findings are also consistent with prior animal-lesion studies that have shown a role for the vestibulocerebellum in the control of the direction of the VOR.

  10. Neural networks underlying the metacognitive uncertainty response.

    PubMed

    Paul, Erick J; Smith, J David; Valentin, Vivian V; Turner, Benjamin O; Barbey, Aron K; Ashby, F Gregory

    2015-10-01

    Humans monitor states of uncertainty that can guide decision-making. These uncertain states are evident behaviorally when humans decline to make a categorization response. Such behavioral uncertainty responses (URs) have also defined the search for metacognition in animals. While a plethora of neuroimaging studies have focused on uncertainty, the brain systems supporting a volitional strategy shift under uncertainty have not been distinguished from those observed in making introspective post-hoc reports of categorization uncertainty. Using rapid event-related fMRI, we demonstrate that the neural activity patterns elicited by humans' URs are qualitatively different from those recruited by associative processes during categorization. Participants performed a one-dimensional perceptual-categorization task in which an uncertainty-response option let them decline to make a categorization response. Uncertainty responding activated a distributed network including prefrontal cortex (PFC), anterior and posterior cingulate cortex (ACC, PCC), anterior insula, and posterior parietal areas; importantly, these regions were distinct from those whose activity was modulated by task difficulty. Generally, our results can be characterized as a large-scale cognitive control network including recently evolved brain regions such as the anterior dorsolateral and medial PFC. A metacognitive theory would view the UR as a deliberate behavioral adjustment rather than just a learned middle category response, and predicts this pattern of results. These neuroimaging results bolster previous behavioral findings, which suggested that different cognitive processes underlie responses due to associative learning versus the declaration of uncertainty. We conclude that the UR represents an elemental behavioral index of metacognition.

  11. Vagal enhancement linking abnormal blood pressure response and subendocardial ischemia in hypertrophic cardiomyopathy.

    PubMed

    Kawasaki, Tatsuya; Sugihara, Hiroki

    2014-01-01

    An abnormal blood pressure response to exercise has been reported to be associated with left ventricular subendocardial ischemia in patients with hypertrophic cardiomyopathy (HCM), but the underlying mechanism remains unclear. We report a case of HCM with an abnormal blood pressure response and subendocardial ischemia, in which the analysis of heart rate variability revealed exercise-induced vagal enhancement. The present case highlights the possible mechanism linking abnormal blood pressure response and left ventricular subendocardial ischemia in patients with HCM.

  12. Neural code alterations and abnormal time patterns in Parkinson’s disease

    NASA Astrophysics Data System (ADS)

    Andres, Daniela Sabrina; Cerquetti, Daniel; Merello, Marcelo

    2015-04-01

    Objective. The neural code used by the basal ganglia is a current question in neuroscience, relevant for the understanding of the pathophysiology of Parkinson’s disease. While a rate code is known to participate in the communication between the basal ganglia and the motor thalamus/cortex, different lines of evidence have also favored the presence of complex time patterns in the discharge of the basal ganglia. To gain insight into the way the basal ganglia code information, we studied the activity of the globus pallidus pars interna (GPi), an output node of the circuit. Approach. We implemented the 6-hydroxydopamine model of Parkinsonism in Sprague-Dawley rats, and recorded the spontaneous discharge of single GPi neurons, in head-restrained conditions at full alertness. Analyzing the temporal structure function, we looked for characteristic scales in the neuronal discharge of the GPi. Main results. At a low-scale, we observed the presence of dynamic processes, which allow the transmission of time patterns. Conversely, at a middle-scale, stochastic processes force the use of a rate code. Regarding the time patterns transmitted, we measured the word length and found that it is increased in Parkinson’s disease. Furthermore, it showed a positive correlation with the frequency of discharge, indicating that an exacerbation of this abnormal time pattern length can be expected, as the dopamine depletion progresses. Significance. We conclude that a rate code and a time pattern code can co-exist in the basal ganglia at different temporal scales. However, their normal balance is progressively altered and replaced by pathological time patterns in Parkinson’s disease.

  13. The visual perception of natural motion: abnormal task-related neural activity in DYT1 dystonia.

    PubMed

    Sako, Wataru; Fujita, Koji; Vo, An; Rucker, Janet C; Rizzo, John-Ross; Niethammer, Martin; Carbon, Maren; Bressman, Susan B; Uluğ, Aziz M; Eidelberg, David

    2015-12-01

    Although primary dystonia is defined by its characteristic motor manifestations, non-motor signs and symptoms have increasingly been recognized in this disorder. Recent neuroimaging studies have related the motor features of primary dystonia to connectivity changes in cerebello-thalamo-cortical pathways. It is not known, however, whether the non-motor manifestations of the disorder are associated with similar circuit abnormalities. To explore this possibility, we used functional magnetic resonance imaging to study primary dystonia and healthy volunteer subjects while they performed a motion perception task in which elliptical target trajectories were visually tracked on a computer screen. Prior functional magnetic resonance imaging studies of healthy subjects performing this task have revealed selective activation of motor regions during the perception of 'natural' versus 'unnatural' motion (defined respectively as trajectories with kinematic properties that either comply with or violate the two-thirds power law of motion). Several regions with significant connectivity changes in primary dystonia were situated in proximity to normal motion perception pathways, suggesting that abnormalities of these circuits may also be present in this disorder. To determine whether activation responses to natural versus unnatural motion in primary dystonia differ from normal, we used functional magnetic resonance imaging to study 10 DYT1 dystonia and 10 healthy control subjects at rest and during the perception of 'natural' and 'unnatural' motion. Both groups exhibited significant activation changes across perceptual conditions in the cerebellum, pons, and subthalamic nucleus. The two groups differed, however, in their responses to 'natural' versus 'unnatural' motion in these regions. In healthy subjects, regional activation was greater during the perception of natural (versus unnatural) motion (P < 0.05). By contrast, in DYT1 dystonia subjects, activation was relatively greater

  14. Infrared neural stimulation (INS) inhibits electrically evoked neural responses in the deaf white cat

    NASA Astrophysics Data System (ADS)

    Richter, Claus-Peter; Rajguru, Suhrud M.; Robinson, Alan; Young, Hunter K.

    2014-03-01

    Infrared neural stimulation (INS) has been used in the past to evoke neural activity from hearing and partially deaf animals. All the responses were excitatory. In Aplysia californica, Duke and coworkers demonstrated that INS also inhibits neural responses [1], which similar observations were made in the vestibular system [2, 3]. In deaf white cats that have cochleae with largely reduced spiral ganglion neuron counts and a significant degeneration of the organ of Corti, no cochlear compound action potentials could be observed during INS alone. However, the combined electrical and optical stimulation demonstrated inhibitory responses during irradiation with infrared light.

  15. Abnormal Social Reward Responses in Anorexia Nervosa: An fMRI Study

    PubMed Central

    Via, Esther; Soriano-Mas, Carles; Sánchez, Isabel; Forcano, Laura; Harrison, Ben J.; Davey, Christopher G.; Pujol, Jesús; Martínez-Zalacaín, Ignacio; Menchón, José M.; Fernández-Aranda, Fernando; Cardoner, Narcís

    2015-01-01

    Patients with anorexia nervosa (AN) display impaired social interactions, implicated in the development and prognosis of the disorder. Importantly, social behavior is modulated by reward-based processes, and dysfunctional at-brain-level reward responses have been involved in AN neurobiological models. However, no prior evidence exists of whether these neural alterations would be equally present in social contexts. In this study, we conducted a cross-sectional social-judgment functional magnetic resonance imaging (fMRI) study of 20 restrictive-subtype AN patients and 20 matched healthy controls. Brain activity during acceptance and rejection was investigated and correlated with severity measures (Eating Disorder Inventory -EDI-2) and with personality traits of interest known to modulate social behavior (The Sensitivity to Punishment and Sensitivity to Reward Questionnaire). Patients showed hypoactivation of the dorsomedial prefrontal cortex (DMPFC) during social acceptance and hyperactivation of visual areas during social rejection. Ventral striatum activation during rejection was positively correlated in patients with clinical severity scores. During acceptance, activation of the frontal opercula-anterior insula and dorsomedial/dorsolateral prefrontal cortices was differentially associated with reward sensitivity between groups. These results suggest an abnormal motivational drive for social stimuli, and involve overlapping social cognition and reward systems leading to a disruption of adaptive responses in the processing of social reward. The specific association of reward-related regions with clinical and psychometric measures suggests the putative involvement of reward structures in the maintenance of pathological behaviors in AN. PMID:26197051

  16. Muted neural response to distress among securely attached people.

    PubMed

    Nash, Kyle; Prentice, Mike; Hirsh, Jacob; McGregor, Ian; Inzlicht, Michael

    2014-08-01

    Neural processes that support individual differences in attachment security and affect regulation are currently unclear. Using electroencephalography, we examined whether securely attached individuals, compared with insecure individuals, would show a muted neural response to experimentally manipulated distress. Participants completed a reaction time task that elicits error commission and the error-related negativity (ERN)-a neural signal sensitive to error-related distress-both before and after a distressing insecurity threat. Despite similar pre-threat levels, secure participants showed a stable ERN, whereas insecure participants showed a post-threat increase in ERN amplitude. These results suggest a neural mechanism that allows securely attached people to regulate distress.

  17. Abnormal task driven neural oscillations in multiple sclerosis: A visuomotor MEG study.

    PubMed

    Barratt, Eleanor L; Tewarie, Prejaas K; Clarke, Margareta A; Hall, Emma L; Gowland, Penny A; Morris, Peter G; Francis, Susan T; Evangelou, Nikos; Brookes, Matthew J

    2017-02-27

    Multiple sclerosis (MS) is a debilitating disease commonly attributed to degradation of white matter myelin. Symptoms include fatigue, as well as problems associated with vision and movement. Although areas of demyelination in white matter are observed routinely in patients undergoing MRI scans, such measures are often a poor predictor of disease severity. For this reason, it is instructive to measure associated changes in brain function. Widespread white-matter demyelination may lead to delays of propagation of neuronal activity, and with its excellent temporal resolution, magnetoencephalography can be used to probe such delays in controlled conditions (e.g., during a task). In healthy subjects, responses to visuomotor tasks are well documented: in motor cortex, movement elicits a localised decrease in the power of beta band oscillations (event-related beta desynchronisation) followed by an increase above baseline on movement cessation (post-movement beta rebound (PMBR)). In visual cortex, visual stimulation generates increased gamma oscillations. In this study, we use a visuomotor paradigm to measure these responses in MS patients and compare them to age- and gender-matched healthy controls. We show a significant increase in the time-to-peak of the PMBR in patients which correlates significantly with the symbol digit modalities test: a measure of information processing speed. A significant decrease in the amplitude of visual gamma oscillations in patients is also seen. These findings highlight the potential value of electrophysiological imaging in generating a new understanding of visual disturbances and abnormal motor control in MS patients. Hum Brain Mapp, 2017. © 2017 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

  18. Prevalence of hematological abnormalities in patients with Sheehan's syndrome: response to replacement of glucocorticoids and thyroxine.

    PubMed

    Laway, Bashir Ahmad; Mir, Shahnaz Ahmad; Bashir, Mir Iftikhar; Bhat, Javid Rasool; Samoon, Jeelani; Zargar, Abdul Hamid

    2011-03-01

    Anemia and other hematological abnormalities are common in patients with Sheehan's syndrome. The response of these abnormalities to replacement of thyroxine and glucocorticoids is not clear. The aim of the present study was to document the profile of hematological abnormalities and response to treatment in patients with Sheehan's syndrome. Forty patients of Sheehan's syndrome and an equal number of age and parity matched healthy controls were studied for prevalence of hematological abnormalities. Hemoglobin concentration, hematocrit, red cell, white cell and platelet count were significantly decreased in patients with Sheehan's syndrome compared to controls. Frequency of anemia, leucopenia, thrombocytopenia and pancytopenia was significantly higher in these patients compared to controls. After achieving euthyroid and eucortisol state, there was a complete recovery of these hematological abnormalities. We conclude that anemia and other cytopenias are common in patients with Sheehan's syndrome and replacement with thyroxine and glucocorticoids results in complete recovery of these abnormalities.

  19. Identification of Abnormal System Noise Temperature Patterns in Deep Space Network Antennas Using Neural Network Trained Fuzzy Logic

    NASA Technical Reports Server (NTRS)

    Lu, Thomas; Pham, Timothy; Liao, Jason

    2011-01-01

    This paper presents the development of a fuzzy logic function trained by an artificial neural network to classify the system noise temperature (SNT) of antennas in the NASA Deep Space Network (DSN). The SNT data were classified into normal, marginal, and abnormal classes. The irregular SNT pattern was further correlated with link margin and weather data. A reasonably good correlation is detected among high SNT, low link margin and the effect of bad weather; however we also saw some unexpected non-correlations which merit further study in the future.

  20. GABA in the insula - a predictor of the neural response to interoceptive awareness.

    PubMed

    Wiebking, Christine; Duncan, Niall W; Tiret, Brice; Hayes, Dave J; Marjaǹska, Małgorzata; Doyon, Julien; Bajbouj, Malek; Northoff, Georg

    2014-02-01

    The insula has been identified as a key region involved in interoceptive awareness. Whilst imaging studies have investigated the neural activation patterns in this region involved in intero- and exteroceptive awareness, the underlying biochemical mechanisms still remain unclear. In order to investigate these, a well-established fMRI task targeting interoceptive awareness (heartbeat counting) and exteroceptive awareness (tone counting) was combined with magnetic resonance spectroscopy (MRS). Controlling for physiological noise, neural activity in the insula during intero- and exteroceptive awareness was confirmed in an independent data sample using the same fMRI design. Focussing on MRS values from the left insula and combining them with neural activity during intero- and exteroceptive awareness in the same healthy individuals, we demonstrated that GABA concentration in a region highly involved in interoceptive processing is correlated with neural responses to interoceptive stimuli, as opposed to exteroceptive stimuli. In addition, both GABA and interoceptive signal changes in the insula predicted the degree of depressed affect, as measured by the Beck Hopelessness Scale. On the one hand, the association between GABA concentration and neural activity during interoceptive awareness provides novel insight into the biochemical underpinnings of insula function and interoception. On the other, through the additional association of both GABA and neural activity during interoception with depressed affect, these data also bear potentially important implications for psychiatric disorders like depression and anxiety, where GABAergic deficits, altered insula function and abnormal affect coincide.

  1. Neural Correlates of Response Inhibition in Adolescents Prospectively Predict Regular Tobacco Smoking

    PubMed Central

    Anokhin, Andrey P.; Golosheykin, Simon

    2016-01-01

    Inhibitory deficits have been widely reported and substance abuse, however, it remains unclear whether such deficits represent a determinant or a consequence of substance use. Here we show, using a prospective longitudinal design, that developmental abnormalities in the neural correlates of response inhibition in adolescents increase the risk for subsequent cigarette smoking. Reduced No-Go P3 amplitude, delayed latency of Go P3 peak, and reduced synchrony of neuronal oscillations at age 14 prospectively predicted regular smoking at age 18. The present findings suggest that functional brain correlates of response inhibition represent a developmental marker of risk for future substance abuse. PMID:27392089

  2. Upper esophageal sphincter abnormalities are strongly predictive of treatment response in patients with achalasia

    PubMed Central

    Mathews, Simon C; Ciarleglio, Maria; Chavez, Yamile Haito; Clarke, John O; Stein, Ellen; Chander Roland, Bani

    2014-01-01

    AIM: To investigate the relationship between upper esophageal sphincter abnormalities achalasia treatment METHODS: We performed a retrospective study of 41 consecutive patients referred for high resolution esophageal manometry with a final manometric diagnosis of achalasia. Patients were sub-divided by presence or absence of Upper esophageal sphincter (UES) abnormality, and clinical and manometric profiles were compared. Correlation between UES abnormality and sub-type (i.e., hypertensive, hypotensive or impaired relaxation) and a number of variables, including qualitative treatment response, achalasia sub-type, co-morbid medical illness, psychiatric illness, surgical history, dominant presenting symptom, treatment type, age and gender were also evaluated. RESULTS: Among all 41 patients, 24 (58.54%) had a UES abnormality present. There were no significant differences between the groups in terms of age, gender or any other clinical or demographic profiles. Among those with UES abnormalities, the majority were either hypertensive (41.67%) or had impaired relaxation (37.5%) as compared to hypotensive (20.83%), although this did not reach statistical significance (P = 0.42). There was no specific association between treatment response and treatment type received; however, there was a significant association between UES abnormalities and treatment response. In patients with achalasia and concomitant UES abnormalities, 87.5% had poor treatment response, while only 12.5% had favorable response. In contrast, in patients with achalasia and no UES abnormalities, the majority (78.57%) had good treatment response, as compared to 21.43% with poor treatment response (P = 0.0001). After controlling for achalasia sub-type, those with UES abnormality had 26 times greater odds of poor treatment response than those with no UES abnormality (P = 0.009). Similarly, after controlling for treatment type, those with UES abnormality had 13.9 times greater odds of poor treatment response

  3. Waking State: Rapid Variations Modulate Neural and Behavioral Responses

    PubMed Central

    McGinley, Matthew J.; Vinck, Martin; Reimer, Jacob; Batista-Brito, Renata; Zagha, Edward; Cadwell, Cathryn R.

    2015-01-01

    The state of the brain and body constantly varies on rapid and slow time scales. These variations contribute to the apparent noisiness of sensory responses at both the neural and behavioral level. Recent investigations of rapid state changes in awake, behaving animals have provided insight into the mechanisms by which optimal sensory encoding and behavioral performance are achieved. Fluctuations in state, as indexed by pupillometry, impact both the “signal” (sensory evoked response) and the “noise” (spontaneous activity) of cortical responses. By taking these fluctuations into account, neural response (co-)variability is significantly reduced, revealing the brain to be more reliable and predictable than previously thought. PMID:26402600

  4. Abnormal Structural Correlates of Response Perseveration in Individuals With Psychopathy

    PubMed Central

    Yang, Yaling; Raine, Adrian; Colletti, Patrick; Toga, Arthur W.; Narr, Katherine L.

    2011-01-01

    Structural deficits in the frontotemporal network have been shown in individuals with psychopathy and are posited to contribute to neuropsychological impairments such as response perseveration. However, no study to date has examined structural correlates of response perseveration in individuals with psychopathy. In this structural MRI study, the authors found higher correlations between increased response perseveration and reduced cortical thickness in the orbitofrontal and anterior temporal regions in individuals with psychopathy than in healthy-comparison subjects. The findings provide preliminary evidence suggesting potential contributions of frontotemporal structural deficits in neurocognitive impairment with perseveration in individuals with psychopathy. PMID:21304146

  5. Abnormal hypothalamic response to light in Seasonal Affective Disorder

    PubMed Central

    Gilles, Vandewalle; Marc, Hébert; Catherine, Beaulieu; Laurence, Richard; Véronique, Daneault; Marie-Lou, Garon; Jean, Leblanc; Didier, Grandjean; Pierre, Maquet; Sophie, Schwartz; Marie, Dumont; Julien, Doyon; Julie, Carrier

    2017-01-01

    Background Vulnerability to the reduction in natural light associated with fall/winter is generally accepted as the main trigger of Seasonal Affective Disorder (SAD), while light therapy is a treatment of choice of the disorder. However, the relationship between exposure to light and mood regulation remains unclear. As compared to green light, blue light was shown to acutely modulate emotion brain processing in healthy individuals. Here, we investigated the impact of light on emotion brain processing in patients with SAD and healthy controls and its relationship with retinal light sensitivity. Methods Fourteen symptomatic untreated patients with SAD (34.5 ± 8.2 y.o.; 9F) and sixteen healthy controls (32.3 ± 7.7 y.o.; 11F) performed an auditory emotional task in functional Magnetic Resonance Imaging (fMRI) during the fall/winter season, while being exposed to alternating blue and green monochromatic light. Scotopic and photopic retinal light sensitivities were then evaluated using electroretinography. Results Blue light enhanced responses to auditory emotional stimuli in the posterior hypothalamus in patients with SAD, while green light decreased these responses. These effects of blue and green light were not observed in healthy controls despite similar retinal sensitivity in SAD and control subjects. Conclusions; These results point to the posterior hypothalamus as the neurobiological substrate involved in specific aspects of SAD, including a distinctive response to light and altered emotional responses. PMID:21820647

  6. Muted neural response to distress among securely attached people

    PubMed Central

    Prentice, Mike; Hirsh, Jacob; McGregor, Ian; Inzlicht, Michael

    2014-01-01

    Neural processes that support individual differences in attachment security and affect regulation are currently unclear. Using electroencephalography, we examined whether securely attached individuals, compared with insecure individuals, would show a muted neural response to experimentally manipulated distress. Participants completed a reaction time task that elicits error commission and the error-related negativity (ERN)—a neural signal sensitive to error-related distress—both before and after a distressing insecurity threat. Despite similar pre-threat levels, secure participants showed a stable ERN, whereas insecure participants showed a post-threat increase in ERN amplitude. These results suggest a neural mechanism that allows securely attached people to regulate distress. PMID:23887815

  7. Affective neural response to restricted interests in Autism Spectrum Disorders

    PubMed Central

    Cascio, Carissa J.; Foss-Feig, Jennifer H.; Heacock, Jessica; Schauder, Kimberly B.; Loring, Whitney A.; Rogers, Baxter P.; Pryweller, Jennifer R.; Newsom, Cassandra R.; Cockhren, Jurnell; Cao, Aize; Bolton, Scott

    2013-01-01

    Background Restricted interests are a class of repetitive behavior in autism spectrum disorders (ASD) whose intensity and narrow focus often contribute to significant interference with daily functioning. While numerous neuroimaging studies have investigated executive circuits as putative neural substrates of repetitive behavior, recent work implicates affective neural circuits in restricted interests. We sought to explore the role of affective neural circuits and determine how restricted interests are distinguished from hobbies or interests in typical development. Methods We compared a group of children with ASD to a typically developing (TD) group of children with strong interests or hobbies, employing parent report, an operant behavioral task, and functional imaging with personalized stimuli based on individual interests. Results While performance on the operant task was similar between the two groups, parent report of intensity and interference of interests was significantly higher in the ASD group. Both the ASD and TD groups showed increased BOLD response in widespread affective neural regions to pictures of their own interest. When viewing pictures of other children's interests, the TD group showed a similar pattern, whereas BOLD response in the ASD group was much more limited. Increased BOLD response in the insula and anterior cingulate cortex distinguished the ASD from the TD group, and parent report of the intensity and interference with daily life of the child's restricted interest predicted insula response. Conclusions While affective neural network response and operant behavior are comparable in typical and restricted interests, the narrowness of focus that clinically distinguishes restricted interests in ASD is reflected in more interference in daily life and aberrantly enhanced insula and anterior cingulate response to individuals’ own interests in the ASD group. These results further support the involvement of affective neural networks in repetitive

  8. Neural correlates of single-vessel haemodynamic responses in vivo.

    PubMed

    O'Herron, Philip; Chhatbar, Pratik Y; Levy, Manuel; Shen, Zhiming; Schramm, Adrien E; Lu, Zhongyang; Kara, Prakash

    2016-06-16

    Neural activation increases blood flow locally. This vascular signal is used by functional imaging techniques to infer the location and strength of neural activity. However, the precise spatial scale over which neural and vascular signals are correlated is unknown. Furthermore, the relative role of synaptic and spiking activity in driving haemodynamic signals is controversial. Previous studies recorded local field potentials as a measure of synaptic activity together with spiking activity and low-resolution haemodynamic imaging. Here we used two-photon microscopy to measure sensory-evoked responses of individual blood vessels (dilation, blood velocity) while imaging synaptic and spiking activity in the surrounding tissue using fluorescent glutamate and calcium sensors. In cat primary visual cortex, where neurons are clustered by their preference for stimulus orientation, we discovered new maps for excitatory synaptic activity, which were organized similarly to those for spiking activity but were less selective for stimulus orientation and direction. We generated tuning curves for individual vessel responses for the first time and found that parenchymal vessels in cortical layer 2/3 were orientation selective. Neighbouring penetrating arterioles had different orientation preferences. Pial surface arteries in cats, as well as surface arteries and penetrating arterioles in rat visual cortex (where orientation maps do not exist), responded to visual stimuli but had no orientation selectivity. We integrated synaptic or spiking responses around individual parenchymal vessels in cats and established that the vascular and neural responses had the same orientation preference. However, synaptic and spiking responses were more selective than vascular responses--vessels frequently responded robustly to stimuli that evoked little to no neural activity in the surrounding tissue. Thus, local neural and haemodynamic signals were partly decoupled. Together, these results indicate

  9. Neural correlates of emotional responses to music: an EEG study.

    PubMed

    Daly, Ian; Malik, Asad; Hwang, Faustina; Roesch, Etienne; Weaver, James; Kirke, Alexis; Williams, Duncan; Miranda, Eduardo; Nasuto, Slawomir J

    2014-06-24

    This paper presents an EEG study into the neural correlates of music-induced emotions. We presented participants with a large dataset containing musical pieces in different styles, and asked them to report on their induced emotional responses. We found neural correlates of music-induced emotion in a number of frequencies over the pre-frontal cortex. Additionally, we found a set of patterns of functional connectivity, defined by inter-channel coherence measures, to be significantly different between groups of music-induced emotional responses.

  10. Abnormal brainstem auditory response in young females with ADHD.

    PubMed

    Claesdotter-Hybbinette, Emma; Safdarzadeh-Haghighi, Maryam; Råstam, Maria; Lindvall, Magnus

    2015-10-30

    Studies have shown that the auditory brainstem response (ABR) is often affected in neurodevelopmental disorders. The aim of this study is to investigate possible differences in ABR between young females with ADHD compared to control subjects. This study focuses on young females, age 7-17 with ADHD, comparing the ABR of 43 young females with ADHD to 21 age- and gender-matched control subjects. Young females with ADHD have a significantly different ABR in a region between cochlear nucleus and superior olivary complex as well as in the thalamic region compared to control subjects. These data indicate specific differences in ABR between girls with ADHD compared to female controls.

  11. Sepsis: Multiple Abnormalities, Heterogeneous Responses, and Evolving Understanding

    PubMed Central

    Iskander, Kendra N.; Osuchowski, Marcin F.; Stearns-Kurosawa, Deborah J.; Kurosawa, Shinichiro; Stepien, David; Valentine, Catherine

    2013-01-01

    Sepsis represents the host's systemic inflammatory response to a severe infection. It causes substantial human morbidity resulting in hundreds of thousands of deaths each year. Despite decades of intense research, the basic mechanisms still remain elusive. In either experimental animal models of sepsis or human patients, there are substantial physiological changes, many of which may result in subsequent organ injury. Variations in age, gender, and medical comorbidities including diabetes and renal failure create additional complexity that influence the outcomes in septic patients. Specific system-based alterations, such as the coagulopathy observed in sepsis, offer both potential insight and possible therapeutic targets. Intracellular stress induces changes in the endoplasmic reticulum yielding misfolded proteins that contribute to the underlying pathophysiological changes. With these multiple changes it is difficult to precisely classify an individual's response in sepsis as proinflammatory or immunosuppressed. This heterogeneity also may explain why most therapeutic interventions have not improved survival. Given the complexity of sepsis, biomarkers and mathematical models offer potential guidance once they have been carefully validated. This review discusses each of these important factors to provide a framework for understanding the complex and current challenges of managing the septic patient. Clinical trial failures and the therapeutic interventions that have proven successful are also discussed. PMID:23899564

  12. Neural correlates of single vessel hemodynamic responses in vivo

    PubMed Central

    O'Herron, Philip; Chhatbar, Pratik Y; Levy, Manuel; Shen, Zhiming; Schramm, Adrien E; Lu, Zhongyang; Kara, Prakash

    2016-01-01

    Neural activation increases blood flow locally. This vascular signal is used by functional imaging techniques to infer the location and strength of neural activity1,2. However, the precise spatial scale over which neural and vascular signals are correlated is unknown. Furthermore, the relative role of synaptic and spiking activity in driving hemodynamic signals is controversial3-9. Prior studies recorded local field potentials (LFPs) as a measure of synaptic activity together with spiking activity and low-resolution hemodynamic imaging. Here we used two-photon microscopy to measure sensory-evoked responses of individual blood vessels (dilation, blood velocity) while imaging synaptic and spiking activity in the surrounding tissue using fluorescent glutamate and calcium sensors. In cat primary visual cortex, where neurons are clustered by their preference for stimulus orientation, we discovered new maps for excitatory synaptic activity, which were organized similar to spiking activity but were less selective for stimulus orientation and direction. We generated tuning curves for individual vessel responses for the first time and found that parenchymal vessels in cortical layer 2/3 were orientation selective. Neighboring penetrating arterioles had different orientation preferences. Pial surface arteries in cats, as well as surface arteries and penetrating arterioles in rat visual cortex (where orientation maps do not exist10), responded to visual stimuli but had no orientation selectivity. We integrated synaptic or spiking responses around individual parenchymal vessels in cats and established that the vascular and neural responses had the same orientation preference. However, synaptic and spiking responses were more selective than vascular responses—vessels frequently responded robustly to stimuli that evoked little to no neural activity in the surrounding tissue. Thus, local neural and hemodynamic signals were partly decoupled. Together, these results indicate that

  13. Abnormal lymphocyte response to ultraviolet radiation in multiple skin cancer

    SciTech Connect

    Munch-Petersen, B.; Frentz, G.; Squire, B.; Wallevik, K.; Horn, C.C.; Reymann, F.; Faber, M. )

    1985-06-01

    The lymphocyte response to ultraviolet radiation (254 nm) was investigated by two different methods in 29 unselected patients with multiple epidermal cancer. The ultraviolet-induced DNA synthesis was determined as the increase in incorporation of (/sup 3/H)thymidine in irradiated cells compared with non-irradiated cells after incubation for 2 h. The ultraviolet tolerance was measured as the ultraviolet dose necessary for 50% reduction in phytohemagglutinin-stimulated lymphocyte proliferation. Patients with both squamous cell differentiated tumours and basal cell carcinomas had very high ultraviolet-induced DNA synthesis values. The ultraviolet tolerance in patient lymphocytes was considerably lower than in control lymphocytes with the lowest values occurring in patients with clinical sun intolerance. These investigations may be of predictive value in skin carcinogenesis.

  14. Spreading Photoparoxysmal EEG Response is Associated with an Abnormal Cortical Excitability Pattern

    ERIC Educational Resources Information Center

    Siniatchkin, Michael; Groppa, Sergey; Jerosch, Bettina; Muhle, Hiltrud; Kurth, Christoph; Shepherd, Alex J.; Siebner, Hartwig; Stephani, Ulrich

    2007-01-01

    Photosensitivity or photoparoxysmal response (PPR) is a highly heritable electroencephalographic trait characterized by an abnormal cortical response to intermittent photic stimulation (IPS). In PPR-positive individuals, IPS induces spikes, spike-waves or intermittent slow waves. The PPR may be restricted to posterior visual areas (i.e. local PPR…

  15. Prediction and control of neural responses to pulsatile electrical stimulation.

    PubMed

    Campbell, Luke J; Sly, David James; O'Leary, Stephen John

    2012-04-01

    This paper aims to predict and control the probability of firing of a neuron in response to pulsatile electrical stimulation of the type delivered by neural prostheses such as the cochlear implant, bionic eye or in deep brain stimulation. Using the cochlear implant as a model, we developed an efficient computational model that predicts the responses of auditory nerve fibers to electrical stimulation and evaluated the model's accuracy by comparing the model output with pooled responses from a group of guinea pig auditory nerve fibers. It was found that the model accurately predicted the changes in neural firing probability over time to constant and variable amplitude electrical pulse trains, including speech-derived signals, delivered at rates up to 889 pulses s(-1). A simplified version of the model that did not incorporate adaptation was used to adaptively predict, within its limitations, the pulsatile electrical stimulus required to cause a desired response from neurons up to 250 pulses s(-1). Future stimulation strategies for cochlear implants and other neural prostheses may be enhanced using similar models that account for the way that neural responses are altered by previous stimulation.

  16. Prediction and control of neural responses to pulsatile electrical stimulation

    NASA Astrophysics Data System (ADS)

    Campbell, Luke J.; Sly, David James; O'Leary, Stephen John

    2012-04-01

    This paper aims to predict and control the probability of firing of a neuron in response to pulsatile electrical stimulation of the type delivered by neural prostheses such as the cochlear implant, bionic eye or in deep brain stimulation. Using the cochlear implant as a model, we developed an efficient computational model that predicts the responses of auditory nerve fibers to electrical stimulation and evaluated the model's accuracy by comparing the model output with pooled responses from a group of guinea pig auditory nerve fibers. It was found that the model accurately predicted the changes in neural firing probability over time to constant and variable amplitude electrical pulse trains, including speech-derived signals, delivered at rates up to 889 pulses s-1. A simplified version of the model that did not incorporate adaptation was used to adaptively predict, within its limitations, the pulsatile electrical stimulus required to cause a desired response from neurons up to 250 pulses s-1. Future stimulation strategies for cochlear implants and other neural prostheses may be enhanced using similar models that account for the way that neural responses are altered by previous stimulation.

  17. Abnormal cardiovascular responses induced by localized high power microwave exposure

    SciTech Connect

    Lu, S.-T; Brown, D.O.; Johnson, C.E.; Mathur, S.P. ); Elson, E.C. )

    1992-05-01

    A hypothesis of microwave-induced circulatory under perfusion was tested in ketamine anesthetized rats whose heart rate, mean arterial pressure, pulse pressure, respiration rate, and body temperatures were monitored continuously. Fifty-eight ventral head and neck exposures in a waveguide consisted of sham-exposure and exposure to continuous wave (CW) and pulsed 1.25 GHz microwaves for 5 min. The 0.5 Hz and 16 Hz pulsemodulated microwaves were delivered at 400 kW peak power. The CW microwaves were 2 and 6.4 W. The average specific absorption rate was 4.75 W/kg per watt transmitted in the brain and 17.15 W/kg per watt transmitted in the neck. Respiration rate and mean arterial pressure were not altered. Changes in heart rate and pulse pressure were observed in rats exposed to higher power but not to the lower average power microwaves. Depression of pulse pressure, an indication of a decrease in stroke volume, and increased or decreased heart rate were noted in presence of whole-body hyperthermia. The cardiac output of those animals exposed to higher average power microwaves was considered to be below normal as hypothesized. Decreased cardiac output and normal mean arterial pressure resulted in an increase in the total peripheral resistance which was contrary to the anticipated thermal response of animals.

  18. Functional brain abnormalities in psychiatric disorders: neural mechanisms to detect and resolve cognitive conflict and interference.

    PubMed

    Melcher, Tobias; Falkai, Peter; Gruber, Oliver

    2008-11-01

    In the present article, we review functional neuroimaging studies on interference processing and performance monitoring in three groups of psychiatric disorders, (1) mood disorders, (2) schizophrenia, and (3) obsessive-compulsive disorder (OCD). Ad (1) Behavioral performance measures suggest an impaired interference resolution capability in symptomatic bipolar disorder patients. A series of neuroimaging analyses found alterations in the ACC-DLPFC system in mood disorder (unipolar depressed and bipolar) patients, putatively reflective of an abnormal interplay of monitoring and executive neurocognitive functions. Other studies of euthymic bipolar patients showed relatively decreased interference-related activation in rostroventral PFC which conceivably underlies defective inhibitory control. Ad (2) Behavioral Stroop studies revealed a specific performance pattern of schizophrenia patients (normal RT interference but increased error interference and RT facilitation) suggestive of a deficit in ignoring irrelevant (word) information. Moreover, reduced/absent behavioral post-error and post-conflict adaptation effects suggest alterations in performance monitoring and/or adjustment capability in these patients. Neuroimaging findings converge to suggest a disorder-related abnormal neurophysiology in ACC which consistently showed conflict- and error-related hypoactivation that, however, appeared to be modulated by different factors. Moreover, studies suggest a specific deficit in context processing in schizophrenia, evidently related to activation reduction in DLPFC. Ad (3) Behavioral findings provide evidence for impaired interference resolution in OCD. Neuroimaging results consistently showed conflict- and error-related ACC hyperactivation which--conforming OCD pathogenesis models--can be conclusively interpreted as reflecting overactive performance monitoring. Taken together, interference resolution and performance monitoring appeared to be fruitful concepts in the

  19. Attentional deployment impacts neural response to regret

    PubMed Central

    Liu, Zhiyuan; Li, Lin; Zheng, Li; Xu, Min; Zhou, Fanzhi Anita; Guo, Xiuyan

    2017-01-01

    Regret results from comparing non-optimal outcomes containing both gain and loss parts to better alternatives during decision-making. The present fMRI study aimed to explore whether levels of regret could change when gain or loss part of a non-optimal outcome was focused during a sequential risk taking task, i.e. the effect of an important emotional regulation strategy named as attentional deployment on regret. Participants were asked to open a series of boxes consecutively and decided when to stop. Each box contained a reward, except for one containing a devil to zero one’s gain in the trial. After participants stopped, both collected gains and missed chances were revealed. Besides, participants were induced to focus on collected gains (GF) or missed chances (MF), by highlighting different parts of the outcome with red squares. Behaviorally, participants rated less regret to their decisions in GF than MF context. Moreover, participants tended to be less risk-taking after GF context relative to MF. At the neural level, bilateral straitum showed increased activations in both optimal outcome and GF context. However, right MFG and IPL only showed stronger activation in GF than MF context. Additionally, pgACC and mPFC activations were found only in optimal outcome. PMID:28145480

  20. From neural responses to population behavior: neural focus group predicts population-level media effects.

    PubMed

    Falk, Emily B; Berkman, Elliot T; Lieberman, Matthew D

    2012-05-01

    Can neural responses of a small group of individuals predict the behavior of large-scale populations? In this investigation, brain activations were recorded while smokers viewed three different television campaigns promoting the National Cancer Institute's telephone hotline to help smokers quit (1-800-QUIT-NOW). The smokers also provided self-report predictions of the campaigns' relative effectiveness. Population measures of the success of each campaign were computed by comparing call volume to 1-800-QUIT-NOW in the month before and the month after the launch of each campaign. This approach allowed us to directly compare the predictive value of self-reports with neural predictors of message effectiveness. Neural activity in a medial prefrontal region of interest, previously associated with individual behavior change, predicted the population response, whereas self-report judgments did not. This finding suggests a novel way of connecting neural signals to population responses that has not been previously demonstrated and provides information that may be difficult to obtain otherwise.

  1. Neural Basis of Adaptive Response Time Adjustment during Saccade Countermanding

    PubMed Central

    Pouget, Pierre; Logan, Gordon D.; Palmeri, Thomas J.; Boucher, Leanne; Paré, Martin; Schall, Jeffrey D.

    2011-01-01

    Humans and macaque monkeys adjust their response time adaptively in stop signal (countermanding) tasks, responding slower after stop-signal trials than after control trials with no stop signal. We investigated the neural mechanism underlying this adaptive response time adjustment in macaque monkeys performing a saccade countermanding task. Earlier research showed that movements are initiated when the random accumulation of presaccadic movement-related activity reaches a fixed threshold. We found that a systematic delay in response time after stop signal trials was accomplished not through a change of threshold, baseline, or accumulation rate, but instead through a change in the time when activity first began to accumulate. The neurons underlying movement initiation have been identified with mathematical accumulator models of response time performance. Therefore, this new result provides surprising new insights into the neural instantiation of stochastic accumulator models and the mechanisms through which executive control can be exerted. PMID:21880921

  2. Motivational orientation modulates the neural response to reward.

    PubMed

    Linke, Julia; Kirsch, Peter; King, Andrea V; Gass, Achim; Hennerici, Michael G; Bongers, André; Wessa, Michèle

    2010-02-01

    Motivational orientation defines the source of motivation for an individual to perform a particular action and can either originate from internal desires (e.g., interest) or external compensation (e.g., money). To this end, motivational orientation should influence the way positive or negative feedback is processed during learning situations and this might in turn have an impact on the learning process. In the present study, we thus investigated whether motivational orientation, i.e., extrinsic and intrinsic motivation modulates the neural response to reward and punishment as well as learning from reward and punishment in 33 healthy individuals. To assess neural responses to reward, punishment and learning of reward contingencies we employed a probabilistic reversal learning task during functional magnetic resonance imaging. Extrinsic and intrinsic motivation were assessed with a self-report questionnaire. Rewarding trials fostered activation in the medial orbitofrontal cortex and anterior cingulate gyrus (ACC) as well as the amygdala and nucleus accumbens, whereas for punishment an increased neural response was observed in the medial and inferior prefrontal cortex, the superior parietal cortex and the insula. High extrinsic motivation was positively correlated to increased neural responses to reward in the ACC, amygdala and putamen, whereas a negative relationship between intrinsic motivation and brain activation in these brain regions was observed. These findings show that motivational orientation indeed modulates the responsiveness to reward delivery in major components of the human reward system and therefore extends previous results showing a significant influence of individual differences in reward-related personality traits on the neural processing of reward.

  3. Abnormal Neural Oscillations in Schizophrenia Assessed by Spectral Power Ratio of MEG During Word Processing.

    PubMed

    Xu, Tingting; Stephane, Massoud; Parhi, Keshab K

    2016-11-01

    This study investigated spectral power of neural oscillations associated with word processing in schizophrenia. Magnetoencephalography (MEG) data were acquired from 12 schizophrenia patients and 10 healthy controls during a visual word processing task. Two spectral power ratio (SPR) feature sets: the band power ratio (BPR) and the window power ratio (WPR) were extracted from MEG data in five frequency bands, four time windows of word processing, and at locations covering whole head. Cluster-based nonparametric permutation tests were employed to identify SPRs that show significant between-group difference. Machine learning based feature selection and classification techniques were then employed to select optimal combinations of the significant SPR features, and distinguish schizophrenia patients from healthy controls. We identified three BPR clusters and three WPR clusters that show significant oscillation power difference between groups. These include the theta/delta, alpha/delta and beta/delta BPRs during base-to-encode and encode time windows, and the beta band WPR from base to encode and from encode to post-encode windows. Based on two WPR and one BPR features combined, over 95% cross-validation classification accuracy was achieved using three different linear classifiers separately. These features may have potential as quantitative markers that discriminate schizophrenia patients and healthy controls; however, this needs further validation on larger samples.

  4. Neural mechanisms of predatory aggression in rats-implications for abnormal intraspecific aggression.

    PubMed

    Tulogdi, Aron; Biro, Laszlo; Barsvari, Beata; Stankovic, Mona; Haller, Jozsef; Toth, Mate

    2015-04-15

    Our recent studies showed that brain areas that are activated in a model of escalated aggression overlap with those that promote predatory aggression in cats. This finding raised the interesting possibility that the brain mechanisms that control certain types of abnormal aggression include those involved in predation. However, the mechanisms of predatory aggression are poorly known in rats, a species that is in many respects different from cats. To get more insights into such mechanisms, here we studied the brain activation patterns associated with spontaneous muricide in rats. Subjects not exposed to mice, and those which did not show muricide were used as controls. We found that muricide increased the activation of the central and basolateral amygdala, and lateral hypothalamus as compared to both controls; in addition, a ventral shift in periaqueductal gray activation was observed. Interestingly, these are the brain regions from where predatory aggression can be elicited, or enhanced by electrical stimulation in cats. The analysis of more than 10 other brain regions showed that brain areas that inhibited (or were neutral to) cat predatory aggression were not affected by muricide. Brain activation patterns partly overlapped with those seen earlier in the cockroach hunting model of rat predatory aggression, and were highly similar with those observed in the glucocorticoid dysfunction model of escalated aggression. These findings show that the brain mechanisms underlying predation are evolutionarily conservative, and indirectly support our earlier assumption regarding the involvement of predation-related brain mechanisms in certain forms of escalated social aggression in rats.

  5. Personality traits modulate neural responses to emotions expressed in music.

    PubMed

    Park, Mona; Hennig-Fast, Kristina; Bao, Yan; Carl, Petra; Pöppel, Ernst; Welker, Lorenz; Reiser, Maximilian; Meindl, Thomas; Gutyrchik, Evgeny

    2013-07-26

    Music communicates and evokes emotions. The number of studies on the neural correlates of musical emotion processing is increasing but few have investigated the factors that modulate these neural activations. Previous research has shown that personality traits account for individual variability of neural responses. In this study, we used functional magnetic resonance imaging (fMRI) to investigate how the dimensions Extraversion and Neuroticism are related to differences in brain reactivity to musical stimuli expressing the emotions happiness, sadness and fear. 12 participants (7 female, M=20.33 years) completed the NEO-Five Factor Inventory (NEO-FFI) and were scanned while performing a passive listening task. Neurofunctional analyses revealed significant positive correlations between Neuroticism scores and activations in bilateral basal ganglia, insula and orbitofrontal cortex in response to music expressing happiness. Extraversion scores were marginally negatively correlated with activations in the right amygdala in response to music expressing fear. Our findings show that subjects' personality may have a predictive power in the neural correlates of musical emotion processing and should be considered in the context of experimental group homogeneity.

  6. Antipsychotic dose modulates behavioral and neural responses to feedback during reinforcement learning in schizophrenia.

    PubMed

    Insel, Catherine; Reinen, Jenna; Weber, Jochen; Wager, Tor D; Jarskog, L Fredrik; Shohamy, Daphna; Smith, Edward E

    2014-03-01

    Schizophrenia is characterized by an abnormal dopamine system, and dopamine blockade is the primary mechanism of antipsychotic treatment. Consistent with the known role of dopamine in reward processing, prior research has demonstrated that patients with schizophrenia exhibit impairments in reward-based learning. However, it remains unknown how treatment with antipsychotic medication impacts the behavioral and neural signatures of reinforcement learning in schizophrenia. The goal of this study was to examine whether antipsychotic medication modulates behavioral and neural responses to prediction error coding during reinforcement learning. Patients with schizophrenia completed a reinforcement learning task while undergoing functional magnetic resonance imaging. The task consisted of two separate conditions in which participants accumulated monetary gain or avoided monetary loss. Behavioral results indicated that antipsychotic medication dose was associated with altered behavioral approaches to learning, such that patients taking higher doses of medication showed increased sensitivity to negative reinforcement. Higher doses of antipsychotic medication were also associated with higher learning rates (LRs), suggesting that medication enhanced sensitivity to trial-by-trial feedback. Neuroimaging data demonstrated that antipsychotic dose was related to differences in neural signatures of feedback prediction error during the loss condition. Specifically, patients taking higher doses of medication showed attenuated prediction error responses in the striatum and the medial prefrontal cortex. These findings indicate that antipsychotic medication treatment may influence motivational processes in patients with schizophrenia.

  7. Chronic myofascial temporomandibular pain is associated with neural abnormalities in the trigeminal and limbic systems

    PubMed Central

    Shen, Yoshi F.; Goddard, Greg; Mackey, Sean C.

    2010-01-01

    Myofascial pain of the temporomandibular region (M-TMD) is a common, but poorly understood chronic disorder. It is unknown whether the condition is a peripheral problem, or a disorder of the central nervous system (CNS). To investigate possible CNS substrates of M-TMD, we compared the brain morphology of 15 women with M-TMD to 15 age- and gender-matched healthy controls. High-resolution structural brain and brainstem scans were carried out using magnetic resonance imaging (MRI), and data were analyzed using a voxel-based morphometry approach. The M-TMD group evidenced decreased or increased gray matter volume compared to controls in several areas of the trigeminothalamocortical pathway, including brainstem trigeminal sensory nuclei, the thalamus, and the primary somatosensory cortex. In addition, M-TMD individuals showed increased gray matter volume compared to controls in limbic regions such as the posterior putamen, globus pallidus, and anterior insula. Within the M-TMD group, jaw pain, pain tolerance, and pain duration were differentially associated with brain and brainstem gray matter volume. Self-reported pain severity was associated with increased gray matter in the rostral anterior cingulate cortex and posterior cingulate. Sensitivity to pressure algometry was associated with decreased gray matter in the pons, corresponding to the trigeminal sensory nuclei. Longer pain duration was associated with greater gray matter in the posterior cingulate, hippocampus, midbrain, and cerebellum. The pattern of gray matter abnormality found in M-TMD individuals suggests the involvement of trigeminal and limbic system dysregulation, as well as potential somatotopic reorganization in the putamen, thalamus, and somatosensory cortex. PMID:20236763

  8. Mice with Tak1 deficiency in neural crest lineage exhibit cleft palate associated with abnormal tongue development.

    PubMed

    Song, Zhongchen; Liu, Chao; Iwata, Junichi; Gu, Shuping; Suzuki, Akiko; Sun, Cheng; He, Wei; Shu, Rong; Li, Lu; Chai, Yang; Chen, YiPing

    2013-04-12

    Cleft palate represents one of the most common congenital birth defects in humans. TGFβ signaling, which is mediated by Smad-dependent and Smad-independent pathways, plays a crucial role in regulating craniofacial development and patterning, particularly in palate development. However, it remains largely unknown whether the Smad-independent pathway contributes to TGFβ signaling function during palatogenesis. In this study, we investigated the function of TGFβ activated kinase 1 (Tak1), a key regulator of Smad-independent TGFβ signaling in palate development. We show that Tak1 protein is expressed in both the epithelium and mesenchyme of the developing palatal shelves. Whereas deletion of Tak1 in the palatal epithelium or mesenchyme did not give rise to a cleft palate defect, inactivation of Tak1 in the neural crest lineage using the Wnt1-Cre transgenic allele resulted in failed palate elevation and subsequently the cleft palate formation. The failure in palate elevation in Wnt1-Cre;Tak1(F/F) mice results from a malformed tongue and micrognathia, resembling human Pierre Robin sequence cleft of the secondary palate. We found that the abnormal tongue development is associated with Fgf10 overexpression in the neural crest-derived tongue tissue. The failed palate elevation and cleft palate were recapitulated in an Fgf10-overexpressing mouse model. The repressive effect of the Tak1-mediated noncanonical TGFβ signaling on Fgf10 expression was further confirmed by inhibition of p38, a downstream kinase of Tak1, in the primary cell culture of developing tongue. Tak1 thus functions to regulate tongue development by controlling Fgf10 expression and could represent a candidate gene for mutation in human PRS clefting.

  9. Response variance in functional maps: neural darwinism revisited.

    PubMed

    Takahashi, Hirokazu; Yokota, Ryo; Kanzaki, Ryohei

    2013-01-01

    The mechanisms by which functional maps and map plasticity contribute to cortical computation remain controversial. Recent studies have revisited the theory of neural Darwinism to interpret the learning-induced map plasticity and neuronal heterogeneity observed in the cortex. Here, we hypothesize that the Darwinian principle provides a substrate to explain the relationship between neuron heterogeneity and cortical functional maps. We demonstrate in the rat auditory cortex that the degree of response variance is closely correlated with the size of its representational area. Further, we show that the response variance within a given population is altered through training. These results suggest that larger representational areas may help to accommodate heterogeneous populations of neurons. Thus, functional maps and map plasticity are likely to play essential roles in Darwinian computation, serving as effective, but not absolutely necessary, structures to generate diverse response properties within a neural population.

  10. Proportionate responses to life events influence clinicians' judgments of psychological abnormality.

    PubMed

    Kim, Nancy S; Paulus, Daniel J; Gonzalez, Jeffrey S; Khalife, Danielle

    2012-09-01

    Psychological abnormality is a fundamental concept in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR; American Psychiatric Association, 2000) and in all clinical evaluations. How do practicing clinical psychologists use the context of life events to judge the abnormality of a person's current behaviors? The appropriate role of life-event context in assessment has long been the subject of intense debate and scrutiny among clinical theorists, yet relatively little is known about clinicians' own judgments in practice. The authors propose a proportionate-response hypothesis, such that judgments of abnormality are influenced by whether the behaviors are a disproportionate response to past events, rendering them difficult to understand or explain. Licensed, practicing clinical psychologists (N = 77) were presented with vignettes describing hypothetical people's behaviors (disordered, mildly distressed, or unaffected) that had been preceded by either traumatic or mildly distressing events. Experts' judgments of abnormality were strongly and systematically influenced by the degree of mismatch between the past event and current behaviors in strength and valence, such that the greater the mismatch, the more abnormal the person seemed. A separate, additional group of clinical psychologists (N = 20) further confirmed that the greater the degree of mismatch, the greater the perceived difficulty in understanding the patient. These findings held true across clinicians of different theoretical orientations and in disorders for which these patterns of judgments ran contrary to formal recommendations in the DSM-IV-TR (American Psychiatric Association, 2000). The rationality of these effects and implications for clinical decision science are discussed.

  11. Response Monitoring, Repetitive Behaviour and Anterior Cingulate Abnormalities in Autism Spectrum Disorders (ASD)

    ERIC Educational Resources Information Center

    Thakkar, Katharine N.; Polli, Frida E.; Joseph, Robert M.; Tuch, David S.; Hadjikhani, Nouchine; Barton, Jason J. S.; Manoach, Dara S.

    2008-01-01

    Autism spectrum disorders (ASD) are characterized by inflexible and repetitive behaviour. Response monitoring involves evaluating the consequences of behaviour and making adjustments to optimize outcomes. Deficiencies in this function, and abnormalities in the anterior cingulate cortex (ACC) on which it relies, have been reported as contributing…

  12. Neural attention and evaluative responses to gay and lesbian couples.

    PubMed

    Dickter, Cheryl L; Forestell, Catherine A; Mulder, Blakely E

    2015-01-01

    The goal of the current study was to examine whether differential neural attentional capture and evaluative responses for out-group homosexual relative to in-group heterosexual targets occur during social categorization. To this end, 36 heterosexual participants were presented with pictures of heterosexual and homosexual couples in a picture-viewing task that was designed to assess implicit levels of discomfort toward homosexuality and explicit evaluations of pleasantness toward the images. Neural activity in the form of electroencephalogram was recorded during the presentation of the pictures, and event-related potentials resulting from these stimuli were examined. Participants also completed questionnaires that assessed the degree to which they socialized with gays and lesbians. Results demonstrated that relative to straight couples, larger P2 amplitude was observed in response to gay but not to lesbian couples. However, both gay and lesbian couples yielded a larger late positive potential than straight couples. Moreover, the degree to which participants differentially directed early neural attention to out-group lesbian versus in-group straight couples was related to their familiarity with homosexual individuals. This work, which provides an initial understanding of the neural underpinnings of attention toward homosexual couples, suggests that differences in the processing of sexual orientation can occur as early as 200 ms and may be moderated by familiarity.

  13. Predicting splenic abnormality in Hodgkin disease using volume response to epinephrine administration

    SciTech Connect

    Rosen, P.R.; Lasher, J.C.; Weiland, F.L.; Kopp, D.T.

    1982-06-01

    The change in relative splenic volume following epinephrine administration was used to determine splenic abnormality noninvasively. Selective splenic imaging was accomplished with /sup 99m/Tc-labeled heat-treated red blood cells, an LFOV gamma camera, a 30 degrees bilateral rotating slant hole collimator, and bilateral slant hole tomographic software. Relative splenic volumes were plotted over time, and correlated with clinical and histologic data. Eight patients with Hodgkin disease and other lymphomas were examined. Volume response to epinephrine appears to be significantly less in abnormal spleens, and may serve to identify patients with unequivocally normal spleens prior to treatment.

  14. Predicting splenic abnormality in Hodgkin disease using volume response to epinephrine administration

    SciTech Connect

    Rosen P.R.; Lasher, J.C.; Weiland, F.L.; Kopp, D.T.

    1982-06-01

    The change in relative splenic volume following epinephrine administration was used to determine splenic abnormality noninvasively. Selective splenic imaging was accomplished with /sup 99m/Tc-labeled heat-treated red blood cells, an LFOV gamma camera, a 30/sup 0/ bilateral rotating slant hole collimator, and bilateral slant hole tomographic software. Relative splenic volumes were plotted over time, and correlated with clinical and histologic data. Eight patients with Hodgkin disease and other lymphomas were examined. Volume response to epinephrine appears to be significantly less in abnormal spleens, and may serve to identify patients with unequivocally normal spleens prior to treatment.

  15. Analysis of Abnormal Intra-QRS Potentials in Signal-Averaged Electrocardiograms Using a Radial Basis Function Neural Network.

    PubMed

    Lin, Chun-Cheng

    2016-09-27

    Abnormal intra-QRS potentials (AIQPs) are commonly observed in patients at high risk for ventricular tachycardia. We present a method for approximating a measured QRS complex using a non-linear neural network with all radial basis functions having the same smoothness. We extracted the high frequency, but low amplitude intra-QRS potentials using the approximation error to identify possible ventricular tachycardia. With a specified number of neurons, we performed an orthogonal least squares algorithm to determine the center of each Gaussian radial basis function. We found that the AIQP estimation error arising from part of the normal QRS complex could cause clinicians to misjudge patients with ventricular tachycardia. Our results also show that it is possible to correct this misjudgment by combining multiple AIQP parameters estimated using various spread parameters and numbers of neurons. Clinical trials demonstrate that higher AIQP-to-QRS ratios in the X, Y and Z leads are visible in patients with ventricular tachycardia than in normal subjects. A linear combination of 60 AIQP-to-QRS ratios can achieve 100% specificity, 90% sensitivity, and 95.8% total prediction accuracy for diagnosing ventricular tachycardia.

  16. Neural correlates of emotional response inhibition in obsessive-compulsive disorder: A preliminary study.

    PubMed

    Berlin, Heather A; Schulz, Kurt P; Zhang, Sam; Turetzky, Rachel; Rosenthal, David; Goodman, Wayne

    2015-11-30

    Failure to inhibit recurrent anxiety-provoking thoughts is a central symptom of obsessive-compulsive disorder (OCD). Neuroimaging studies suggest inhibitory control and disgust processing abnormalities in patients with OCD. However, the emotional modulation of response inhibition deficits in OCD and their neural correlates remain to be elucidated. For this preliminary study we administered an adapted affective response inhibition paradigm, an emotional go/no-go task, during fMRI to characterize the neural systems underlying disgust-related and fear-related inhibition in nine adults with contamination-type OCD compared to ten matched healthy controls. Participants with OCD had significantly greater anterior insula cortex activation when inhibiting responses to both disgusting (bilateral), and fearful (right-sided) images, compared to healthy controls. They also had increased activation in several frontal, temporal, and parietal regions, but there was no evidence of amygdala activation in OCD or healthy participants and no significant between-group differences in performance on the emotion go/no-go task. The anterior insula appears to play a central role in the emotional modulation of response inhibition in contamination-type OCD to both fearful and disgusting images. The insula may serve as a potential treatment target for contamination-type OCD.

  17. Neural systems for social cognition: gray matter volume abnormalities in boys at high genetic risk of autism symptoms, and a comparison with idiopathic autism spectrum disorder.

    PubMed

    Goddard, Marcia N; Swaab, Hanna; Rombouts, Serge A R B; van Rijn, Sophie

    2016-09-01

    Klinefelter syndrome (47, XXY) is associated with several physical, cognitive, and behavioral consequences. In terms of social development, there is an increased risk of autism symptomatology. However, it remains unclear how social deficits are related to abnormal brain development and to what degree underlying mechanisms of social dysfunction in 47, XXY are similar to, or different from, those in idiopathic autism (ASD). This study was aimed at investigating the neural architecture of brain structures related to social information processing in boys with 47, XXY, also in comparison with boys with idiopathic ASD. MRI scans of 16 boys with 47, XXY, 16 with ASD, and 16 nonclinical, male controls were analyzed using voxel-based morphometry (VBM). A region of interest mask containing the superior temporal cortex, amygdala, orbitofrontal cortex (OFC), insular cortex, and medial frontal cortex was used. The Social Responsiveness Scale (SRS) was used to assess degree of autism spectrum symptoms. The 47, XXY group could not be distinguished from the ASD group on mean SRS scores, and their scores were significantly higher than in controls. VBM showed that boys with 47, XXY have significant gray matter volume reductions in the left and right insula, and the left OFC, compared with controls and boys with ASD. Additionally, boys with 47, XXY had significantly less gray matter in the right superior temporal gyrus than controls. These results imply social challenges associated with 47, XXY may be rooted in neural anatomy, and autism symptoms in boys with 47, XXY and boys with ASD might have, at least partially, different underlying etiologies.

  18. Abnormal Auditory Brainstem Response (ABR) Findings in a Near-Normal Hearing Child with Noonan Syndrome

    PubMed Central

    Jalaei, Bahram; Zakaria, Mohd Normani; Sidek, Dinsuhaimi

    2017-01-01

    Introduction: Noonan syndrome (NS) is a heterogeneous genetic disease that affects many parts of the body. It was named after Dr. Jacqueline Anne Noonan, a paediatric cardiologist. Case Report: We report audiological tests and auditory brainstem response (ABR) findings in a 5-year old Malay boy with NS. Despite showing the marked signs of NS, the child could only produce a few meaningful words. Audiological tests found him to have bilateral mild conductive hearing loss at low frequencies. In ABR testing, despite having good waveform morphology, the results were atypical. Absolute latency of wave V was normal but interpeak latencies of wave’s I-V, I-II, II-III were prolonged. Interestingly, interpeak latency of waves III-V was abnormally shorter. Conclusion: Abnormal ABR results are possibly due to abnormal anatomical condition of brainstem and might contribute to speech delay. PMID:28229064

  19. Response monitoring, repetitive behaviour and anterior cingulate abnormalities in autism spectrum disorders (ASD).

    PubMed

    Thakkar, Katharine N; Polli, Frida E; Joseph, Robert M; Tuch, David S; Hadjikhani, Nouchine; Barton, Jason J S; Manoach, Dara S

    2008-09-01

    Autism spectrum disorders (ASD) are characterized by inflexible and repetitive behaviour. Response monitoring involves evaluating the consequences of behaviour and making adjustments to optimize outcomes. Deficiencies in this function, and abnormalities in the anterior cingulate cortex (ACC) on which it relies, have been reported as contributing factors to autistic disorders. We investigated whether ACC structure and function during response monitoring were associated with repetitive behaviour in ASD. We compared ACC activation to correct and erroneous antisaccades using rapid presentation event-related functional MRI in 14 control and ten ASD participants. Because response monitoring is the product of coordinated activity in ACC networks, we also examined the microstructural integrity of the white matter (WM) underlying this brain region using diffusion tensor imaging (DTI) measures of fractional anisotropy (FA) in 12 control and 12 adult ASD participants. ACC activation and FA were examined in relation to Autism Diagnostic Interview-Revised ratings of restricted and repetitive behaviour. Relative to controls, ASD participants: (i) made more antisaccade errors and responded more quickly on correct trials; (ii) showed reduced discrimination between error and correct responses in rostral ACC (rACC), which was primarily due to (iii) abnormally increased activation on correct trials and (iv) showed reduced FA in WM underlying ACC. Finally, in ASD (v) increased activation on correct trials and reduced FA in rACC WM were related to higher ratings of repetitive behaviour. These findings demonstrate functional and structural abnormalities of the ACC in ASD that may contribute to repetitive behaviour. rACC activity following errors is thought to reflect affective appraisal of the error. Thus, the hyperactive rACC response to correct trials can be interpreted as a misleading affective signal that something is awry, which may trigger repetitive attempts at correction

  20. Soft-Tissue Abnormalities Associated with Treatment-Resistant and Treatment-Responsive Clubfoot

    PubMed Central

    Moon, Daniel K.; Gurnett, Christina A.; Aferol, Hyuliya; Siegel, Marilyn J.; Commean, Paul K.; Dobbs, Matthew B.

    2014-01-01

    Background: Clubfoot treatment commonly fails and often results in impaired quality of life. An understanding of the soft-tissue abnormalities associated with both treatment-responsive and treatment-resistant clubfoot is important to improving the diagnosis of clubfoot, the prognosis for patients, and treatment. Methods: Twenty patients with clubfoot treated with the Ponseti method were recruited for magnetic resonance imaging (MRI) of their lower extremities. Among these were seven patients (six unilateral cases) with treatment-responsive clubfoot and thirteen patients (five unilateral cases) with treatment-resistant clubfoot. Demographic information and physical examination findings were recorded. A descriptive analysis of the soft-tissue abnormalities was performed for both patient cohorts. For the patients with unilateral clubfoot, we calculated the percentage difference in cross-sectional area between the affected limb and the unaffected limb in terms of muscle, subcutaneous fat, intracompartment fat, and total area. With use of the Wilcoxon signed-rank test, we compared inter-leg differences in cross-sectional areas and the intracompartment adiposity index (IAI) between treatment-responsive and treatment-resistant groups. The IAI characterizes the cross-sectional area of fat within a muscle compartment. Results: Extensive soft-tissue abnormalities were more present in patients with treatment-resistant clubfoot than in patients with treatment-responsive clubfoot. Treatment-resistant clubfoot abnormalities included excess epimysial fat and intramuscular fat replacement as well as unique patterns of hypoplasia in specific muscle groups that were present within a subset of patients. Among the unilateral cases, treatment-resistant clubfoot was associated with a significantly greater difference in muscle area between the affected and unaffected limb (−47.8%) compared with treatment-responsive clubfoot (−26.6%) (p = 0.02), a significantly greater difference in

  1. Can responses to basic non-numerical visual features explain neural numerosity responses?

    PubMed

    Harvey, Ben M; Dumoulin, Serge O

    2017-02-07

    Humans and many animals can distinguish between stimuli that differ in numerosity, the number of objects in a set. Human and macaque parietal lobes contain neurons that respond to changes in stimulus numerosity. However, basic non-numerical visual features can affect neural responses to and perception of numerosity, and visual features often co-vary with numerosity. Therefore, it is debated whether numerosity or co-varying low-level visual features underlie neural and behavioral responses to numerosity. To test the hypothesis that non-numerical visual features underlie neural numerosity responses in a human parietal numerosity map, we analyze responses to a group of numerosity stimulus configurations that have the same numerosity progression but vary considerably in their non-numerical visual features. Using ultra-high-field (7T) fMRI, we measure responses to these stimulus configurations in an area of posterior parietal cortex whose responses are believed to reflect numerosity-selective activity. We describe an fMRI analysis method to distinguish between alternative models of neural response functions, following a population receptive field (pRF) modeling approach. For each stimulus configuration, we first quantify the relationships between numerosity and several non-numerical visual features that have been proposed to underlie performance in numerosity discrimination tasks. We then determine how well responses to these non-numerical visual features predict the observed fMRI responses, and compare this to the predictions of responses to numerosity. We demonstrate that a numerosity response model predicts observed responses more accurately than models of responses to simple non-numerical visual features. As such, neural responses in cognitive processing need not reflect simpler properties of early sensory inputs.

  2. Response of traveling waves to transient inputs in neural fields.

    PubMed

    Kilpatrick, Zachary P; Ermentrout, Bard

    2012-02-01

    We analyze the effects of transient stimulation on traveling waves in neural field equations. Neural fields are modeled as integro-differential equations whose convolution term represents the synaptic connections of a spatially extended neuronal network. The adjoint of the linearized wave equation can be used to identify how a particular input will shift the location of a traveling wave. This wave response function is analogous to the phase response curve of limit cycle oscillators. For traveling fronts in an excitatory network, the sign of the shift depends solely on the sign of the transient input. A complementary estimate of the effective shift is derived using an equation for the time-dependent speed of the perturbed front. Traveling pulses are analyzed in an asymmetric lateral inhibitory network and they can be advanced or delayed, depending on the position of spatially localized transient inputs. We also develop bounds on the amplitude of transient input necessary to terminate traveling pulses, based on the global bifurcation structure of the neural field.

  3. Response of traveling waves to transient inputs in neural fields

    NASA Astrophysics Data System (ADS)

    Kilpatrick, Zachary P.; Ermentrout, Bard

    2012-02-01

    We analyze the effects of transient stimulation on traveling waves in neural field equations. Neural fields are modeled as integro-differential equations whose convolution term represents the synaptic connections of a spatially extended neuronal network. The adjoint of the linearized wave equation can be used to identify how a particular input will shift the location of a traveling wave. This wave response function is analogous to the phase response curve of limit cycle oscillators. For traveling fronts in an excitatory network, the sign of the shift depends solely on the sign of the transient input. A complementary estimate of the effective shift is derived using an equation for the time-dependent speed of the perturbed front. Traveling pulses are analyzed in an asymmetric lateral inhibitory network and they can be advanced or delayed, depending on the position of spatially localized transient inputs. We also develop bounds on the amplitude of transient input necessary to terminate traveling pulses, based on the global bifurcation structure of the neural field.

  4. Event-Related Potentials Index Neural Response to Eye Contact.

    PubMed

    Naples, Adam J; Wu, Jia; Mayes, Linda C; McPartland, James C

    2017-04-07

    Sensitivity to eye-contact is a foundation upon which social cognition is built. However, there are no known neural markers characterizing response to reciprocal gaze. Using co-registered EEG and eye-tracking, we measured brain activity while participants viewed faces that responded to their looking patterns. Contingent upon participant gaze, onscreen faces opened their eyes or mouths; in this way we measured brain response to reciprocal eye-contact. We identified two ERP components that were largest in response to reciprocal eye-contact: the N170 and the P300. The magnitude of the components' differences between reciprocal eye-contact and mouth movement predicted self-reported social function. Individuals with greater brain response to reciprocal eye-contact reported more normative scores on measures of autistic traits. These results present the first neural markers of eye-contact, revealing that reciprocal eye-contact is identified in less than 500ms. Furthermore, individual differences in brain response to eye-contact predict meaningful variability in self-reports of social performance.

  5. Compassion training alters altruism and neural responses to suffering.

    PubMed

    Weng, Helen Y; Fox, Andrew S; Shackman, Alexander J; Stodola, Diane E; Caldwell, Jessica Z K; Olson, Matthew C; Rogers, Gregory M; Davidson, Richard J

    2013-07-01

    Compassion is a key motivator of altruistic behavior, but little is known about individuals' capacity to cultivate compassion through training. We examined whether compassion may be systematically trained by testing whether (a) short-term compassion training increases altruistic behavior and (b) individual differences in altruism are associated with training-induced changes in neural responses to suffering. In healthy adults, we found that compassion training increased altruistic redistribution of funds to a victim encountered outside of the training context. Furthermore, increased altruistic behavior after compassion training was associated with altered activation in brain regions implicated in social cognition and emotion regulation, including the inferior parietal cortex and dorsolateral prefrontal cortex (DLPFC), and in DLPFC connectivity with the nucleus accumbens. These results suggest that compassion can be cultivated with training and that greater altruistic behavior may emerge from increased engagement of neural systems implicated in understanding the suffering of other people, executive and emotional control, and reward processing.

  6. Unilateral and bilateral brainstem auditory-evoked response abnormalities in 900 Dalmatian dogs.

    PubMed

    Holliday, T A; Nelson, H J; Williams, D C; Willits, N

    1992-01-01

    In a survey of 900 Dalmatian dogs, brainstem auditory-evoked responses (BAER) and clinical observations were used to determine the incidence and sex distribution of bilateral and unilateral BAER abnormalities and their association with heterochromia iridis (HI). To assess the efficacy of BAER testing in guiding breeding programs, data from 749 dogs (subgroup A), considered to be a sample of the population at large, were compared with data from a subgroup (subgroup B; n = 151) in which selection of breeding stock had been based on BAER testing from the beginning of the 4-year survey. Brainstem auditory-evoked responses were elicited by applying click stimuli unilaterally, while applying a white noise masking sound to the contralateral ear. Under these conditions, BAER were either normal, unilaterally absent, or bilaterally absent. Dogs with bilaterally absent BAER were clinically deaf; dogs with unilaterally absent BAER were not clinically deaf but appeared dependent on their BAER-normal ears for their auditory-cued behavior. Dogs with unilaterally absent BAER often were misidentified as normal by uninformed observers. Among the 900 dogs, 648 (72.0%) were normal, 189 (21.0%) had unilateral absence of BAER, and 63 (7.0%) had bilateral absence of BAER or were clinically deaf and assumed to have bilaterally absent BAER (n = 4). Total incidence in the population sampled was assumed to be higher, because some bilaterally affected dogs that would have been members of subgroup A undoubtedly did not come to our attention. Among females, 24.0% were unilaterally abnormal and 8.2% were bilaterally abnormal whereas, among males, 17.8% were unilaterally abnormal and 5.7% were bilaterally abnormal.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. An analysis of cochlear response harmonics: Contribution of neural excitation

    PubMed Central

    Chertoff, M. E.; Kamerer, A. M.; Peppi, M.; Lichtenhan, J. T.

    2015-01-01

    In this report an analysis of cochlear response harmonics is developed to derive a mathematical function to estimate the gross mechanics involved in the in vivo transfer of acoustic sound into neural excitation (fTr). In a simulation it is shown that the harmonic distortion from a nonlinear system can be used to estimate the nonlinearity, supporting the next phase of the experiment: Applying the harmonic analysis to physiologic measurements to derive estimates of the unknown, in vivo fTr. From gerbil ears, estimates of fTr were derived from cochlear response measurements made with an electrode at the round window niche from 85 Hz tone bursts. Estimates of fTr before and after inducing auditory neuropathy—loss of auditory nerve responses with preserved hair cell responses from neurotoxic treatment with ouabain—showed that the neural excitation from low-frequency tones contributes to the magnitude of fTr but not the sigmoidal, saturating, nonlinear morphology. PMID:26627769

  8. Neural response to reward anticipation is modulated by Gray's impulsivity.

    PubMed

    Hahn, Tim; Dresler, Thomas; Ehlis, Ann-Christine; Plichta, Michael M; Heinzel, Sebastian; Polak, Thomas; Lesch, Klaus-Peter; Breuer, Felix; Jakob, Peter M; Fallgatter, Andreas J

    2009-07-15

    According to the Reinforcement Sensitivity Theory (RST), Gray's dimension of impulsivity, reflecting human trait reward sensitivity, determines the extent to which stimuli activate the Behavioural Approach System (BAS). The potential neural underpinnings of the BAS, however, remain poorly understood. In the present study, we examined the association between Gray's impulsivity as defined by the RST and event-related fMRI BOLD-response to anticipation of reward in twenty healthy human subjects in brain regions previously associated with reward processing. Anticipation of reward during a Monetary Incentive Delay Task elicited activation in key components of the human reward circuitry such as the ventral striatum, the amygdala and the orbitofrontal cortex. Interindividual differences in Gray's impulsivity accounted for a significant amount of variance of the reward-related BOLD-response in the ventral striatum and the orbitofrontal cortex. Specifically, higher trait reward sensitivity was associated with increased activation in response to cues indicating potential reward. Extending previous evidence, here we show that variance in functional brain activation during anticipation of reward is attributed to interindividual differences regarding Gray's dimension of impulsivity. Thus, trait reward sensitivity contributes to the modulation of responsiveness in major components of the human reward system which thereby display a core property of the BAS. Generally, fostering our understanding of the neural underpinnings of the association of reward-related interindividual differences in affective traits might aid researchers in quest for custom-tailored treatments of psychiatric disorders, further disentangling the complex relationship between personality traits, emotion, and health.

  9. Memorable Audiovisual Narratives Synchronize Sensory and Supramodal Neural Responses

    PubMed Central

    2016-01-01

    Abstract Our brains integrate information across sensory modalities to generate perceptual experiences and form memories. However, it is difficult to determine the conditions under which multisensory stimulation will benefit or hinder the retrieval of everyday experiences. We hypothesized that the determining factor is the reliability of information processing during stimulus presentation, which can be measured through intersubject correlation of stimulus-evoked activity. We therefore presented biographical auditory narratives and visual animations to 72 human subjects visually, auditorily, or combined, while neural activity was recorded using electroencephalography. Memory for the narrated information, contained in the auditory stream, was tested 3 weeks later. While the visual stimulus alone led to no meaningful retrieval, this related stimulus improved memory when it was combined with the story, even when it was temporally incongruent with the audio. Further, individuals with better subsequent memory elicited neural responses during encoding that were more correlated with their peers. Surprisingly, portions of this predictive synchronized activity were present regardless of the sensory modality of the stimulus. These data suggest that the strength of sensory and supramodal activity is predictive of memory performance after 3 weeks, and that neural synchrony may explain the mnemonic benefit of the functionally uninformative visual context observed for these real-world stimuli. PMID:27844062

  10. A novel neural response algorithm for protein function prediction

    PubMed Central

    2012-01-01

    Background Large amounts of data are being generated by high-throughput genome sequencing methods. But the rate of the experimental functional characterization falls far behind. To fill the gap between the number of sequences and their annotations, fast and accurate automated annotation methods are required. Many methods, such as GOblet, GOFigure, and Gotcha, are designed based on the BLAST search. Unfortunately, the sequence coverage of these methods is low as they cannot detect the remote homologues. Adding to this, the lack of annotation specificity advocates the need to improve automated protein function prediction. Results We designed a novel automated protein functional assignment method based on the neural response algorithm, which simulates the neuronal behavior of the visual cortex in the human brain. Firstly, we predict the most similar target protein for a given query protein and thereby assign its GO term to the query sequence. When assessed on test set, our method ranked the actual leaf GO term among the top 5 probable GO terms with accuracy of 86.93%. Conclusions The proposed algorithm is the first instance of neural response algorithm being used in the biological domain. The use of HMM profiles along with the secondary structure information to define the neural response gives our method an edge over other available methods on annotation accuracy. Results of the 5-fold cross validation and the comparison with PFP and FFPred servers indicate the prominent performance by our method. The program, the dataset, and help files are available at http://www.jjwanglab.org/NRProF/. PMID:23046521

  11. Expressive suppression and neural responsiveness to nonverbal affective cues

    PubMed Central

    Petrican, Raluca; Rosenbaum, R. Shayna; Grady, Cheryl

    2016-01-01

    responsiveness to nonverbal affective cues, while also suggesting one explanation for the suppressors’ poorer cognitive performance in social situations. Moreover, our results point to a potential neural mechanism supporting the development and perpetuation of expressive suppression as an emotion regulation strategy. PMID:26365712

  12. Neural pathways link social support to attenuated neuroendocrine stress responses.

    PubMed

    Eisenberger, Naomi I; Taylor, Shelley E; Gable, Shelly L; Hilmert, Clayton J; Lieberman, Matthew D

    2007-05-01

    It is well established that a lack of social support constitutes a major risk factor for morbidity and mortality, comparable to risk factors such as smoking, obesity, and high blood pressure. Although it has been hypothesized that social support may benefit health by reducing physiological reactivity to stressors, the mechanisms underlying this process remain unclear. Moreover, to date, no studies have investigated the neurocognitive mechanisms that translate experiences of social support into the health outcomes that follow. To investigate these processes, thirty participants completed three tasks in which daily social support, neurocognitive reactivity to a social stressor, and neuroendocrine responses to a social stressor were assessed. Individuals who interacted regularly with supportive individuals across a 10-day period showed diminished cortisol reactivity to a social stressor. Moreover, greater social support and diminished cortisol responses were associated with diminished activity in the dorsal anterior cingulate cortex (dACC) and Brodmann's area (BA) 8, regions previously associated with the distress of social separation. Lastly, individual differences in dACC and BA 8 reactivity mediated the relationship between high daily social support and low cortisol reactivity, such that supported individuals showed reduced neurocognitive reactivity to social stressors, which in turn was associated with reduced neuroendocrine stress responses. This study is the first to investigate the neural underpinnings of the social support-health relationship and provides evidence that social support may ultimately benefit health by diminishing neural and physiological reactivity to social stressors.

  13. Neural responses to maternal criticism in healthy youth

    PubMed Central

    Siegle, Greg J.; Dahl, Ronald E.; Hooley, Jill M.; Silk, Jennifer S.

    2015-01-01

    Parental criticism can have positive and negative effects on children’s and adolescents’ behavior; yet, it is unclear how youth react to, understand and process parental criticism. We proposed that youth would engage three sets of neural processes in response to parental criticism including the following: (i) activating emotional reactions, (ii) regulating those reactions and (iii) social cognitive processing (e.g. understanding the parent’s mental state). To examine neural processes associated with both emotional and social processing of parental criticism in personally relevant and ecologically valid social contexts, typically developing youth were scanned while they listened to their mother providing critical, praising and neutral statements. In response to maternal criticism, youth showed increased brain activity in affective networks (e.g. subcortical–limbic regions including lentiform nucleus and posterior insula), but decreased activity in cognitive control networks (e.g. dorsolateral prefrontal cortex and caudal anterior cingulate cortex) and social cognitive networks (e.g. temporoparietal junction and posterior cingulate cortex/precuneus). These results suggest that youth may respond to maternal criticism with increased emotional reactivity but decreased cognitive control and social cognitive processing. A better understanding of children’s responses to parental criticism may provide insights into the ways that parental feedback can be modified to be more helpful to behavior and development in youth. PMID:25338632

  14. Intelligence moderates neural responses to monetary reward and punishment.

    PubMed

    Hawes, Daniel R; DeYoung, Colin G; Gray, Jeremy R; Rustichini, Aldo

    2014-05-01

    The relations between intelligence (IQ) and neural responses to monetary gains and losses were investigated in a simple decision task. In 94 healthy adults, typical responses of striatal blood oxygen level-dependent (BOLD) signal after monetary reward and punishment were weaker for subjects with higher IQ. IQ-moderated differential responses to gains and losses were also found for regions in the medial prefrontal cortex, posterior cingulate cortex, and left inferior frontal cortex. These regions have previously been identified with the subjective utility of monetary outcomes. Analysis of subjects' behavior revealed a correlation between IQ and the extent to which choices were related to experienced decision outcomes in preceding trials. Specifically, higher IQ predicted behavior to be more strongly correlated with an extended period of previously experienced decision outcomes, whereas lower IQ predicted behavior to be correlated exclusively to the most recent decision outcomes. We link these behavioral and imaging findings to a theoretical model capable of describing a role for intelligence during the evaluation of rewards generated by unknown probabilistic processes. Our results demonstrate neural differences in how people of different intelligence respond to experienced monetary rewards and punishments. Our theoretical discussion offers a functional description for how these individual differences may be linked to choice behavior. Together, our results and model support the hypothesis that observed correlations between intelligence and preferences may be rooted in the way decision outcomes are experienced ex post, rather than deriving exclusively from how choices are evaluated ex ante.

  15. Social hierarchy modulates neural responses of empathy for pain

    PubMed Central

    Feng, Chunliang; Li, Zhihao; Feng, Xue; Wang, Lili; Tian, Tengxiang

    2016-01-01

    Recent evidence indicates that empathic responses to others’ pain are modulated by various situational and individual factors. However, few studies have examined how empathy and underlying brain functions are modulated by social hierarchies, which permeate human society with an enormous impact on social behavior and cognition. In this study, social hierarchies were established based on incidental skill in a perceptual task in which all participants were mediumly ranked. Afterwards, participants were scanned with functional magnetic resonance imaging while watching inferior-status or superior-status targets receiving painful or non-painful stimulation. The results revealed that painful stimulation applied to inferior-status targets induced higher activations in the anterior insula (AI) and anterior medial cingulate cortex (aMCC), whereas these empathic brain activations were significantly attenuated in response to superior-status targets’ pain. Further, this neural empathic bias to inferior-status targets was accompanied by stronger functional couplings of AI with brain regions important in emotional processing (i.e. thalamus) and cognitive control (i.e. middle frontal gyrus). Our findings indicate that emotional sharing with others’ pain is shaped by relative positions in a social hierarchy such that underlying empathic neural responses are biased toward inferior-status compared with superior-status individuals. PMID:26516169

  16. Association of neural tube defects in children of mothers with MTHFR 677TT genotype and abnormal carbohydrate metabolism risk: a case-control study.

    PubMed

    Cadenas-Benitez, N M; Yanes-Sosa, F; Gonzalez-Meneses, A; Cerrillos, L; Acosta, D; Praena-Fernandez, J M; Neth, O; Gomez de Terreros, I; Ybot-González, P

    2014-03-26

    Abnormalities in maternal folate and carbohydrate metabolism have both been shown to induce neural tube defects (NTD) in humans and animal models. However, the relationship between these two factors in the development of NTDs remains unclear. Data from mothers of children with spina bifida seen at the Unidad de Espina Bífida del Hospital Infantil Virgen del Rocío (case group) were compared to mothers of healthy children with no NTD (control group) who were randomly selected from patients seen at the outpatient ward in the same hospital. There were 25 individuals in the case group and 41 in the control group. Analysis of genotypes for the methylenetetrahydrofolate reductase (MTHFR) 677CT polymorphism in women with or without risk factors for abnormal carbohydrate metabolism revealed that mothers who were homozygous for the MTHFR 677TT polymorphism and at risk of abnormal carbohydrate metabolism were more likely to have offspring with spina bifida and high levels of homocysteine, compared to the control group. The increased incidence of NTDs in mothers homozygous for the MTHFR 677TT polymorphism and at risk of abnormal carbohydrate metabolism stresses the need for careful metabolic screening in pregnant women, and, if necessary, determination of the MTHFR 677CT genotype in those mothers at risk of developing abnormal carbohydrate metabolism.

  17. Roman Catholic beliefs produce characteristic neural responses to moral dilemmas

    PubMed Central

    Flexas, Albert; de Miguel, Pedro; Cela-Conde, Camilo J.; Munar, Enric

    2014-01-01

    This study provides exploratory evidence about how behavioral and neural responses to standard moral dilemmas are influenced by religious belief. Eleven Catholics and 13 Atheists (all female) judged 48 moral dilemmas. Differential neural activity between the two groups was found in precuneus and in prefrontal, frontal and temporal regions. Furthermore, a double dissociation showed that Catholics recruited different areas for deontological (precuneus; temporoparietal junction) and utilitarian moral judgments [dorsolateral prefrontal cortex (DLPFC); temporal poles], whereas Atheists did not (superior parietal gyrus for both types of judgment). Finally, we tested how both groups responded to personal and impersonal moral dilemmas: Catholics showed enhanced activity in DLPFC and posterior cingulate cortex during utilitarian moral judgments to impersonal moral dilemmas and enhanced responses in anterior cingulate cortex and superior temporal sulcus during deontological moral judgments to personal moral dilemmas. Our results indicate that moral judgment can be influenced by an acquired set of norms and conventions transmitted through religious indoctrination and practice. Catholic individuals may hold enhanced awareness of the incommensurability between two unequivocal doctrines of the Catholic belief set, triggered explicitly in a moral dilemma: help and care in all circumstances—but thou shalt not kill. PMID:23160812

  18. Perceived reputation of others modulates empathic neural responses.

    PubMed

    Zheng, Li; Wang, Qianfeng; Cheng, Xuemei; Li, Lin; Yang, Guang; Sun, Lining; Ling, Xiaoli; Guo, Xiuyan

    2016-01-01

    Empathy enables us to understand and share the emotional and affective states of another person and plays a key role in social behaviors. The current study investigated whether and how empathic neural responses to pain were modulated by the perceived reputation of others. Action histories reflecting individuals' past cooperation or betrayal actions in the repeated prisoner's dilemma game were introduced as an index of reputation. We assessed brain activity with functional magnetic resonance imaging while the participants observed individuals with a good or bad reputation receiving or not receiving pain. The results indicated that the participants exhibited reduced empathic responses in AI and dACC to the individual who had a bad reputation relative to the one who had a good reputation, suggesting that their empathy for pain was modulated by the perceived reputation of others.

  19. Neural response imaging (NRI) cochlear mapping: prospects for clinical application.

    PubMed

    Arnold, L; Lindsey, P; Hacking, C; Boyle, P

    2007-12-01

    The objective of the study was to investigate the potential for clinical application of neural response imaging (NRI) cochlear mapping. Cochlear mapping was performed at each fitting session up to at least six months following initial fitting. Stimulation was delivered to one electrode site. NRI was recorded from each of the remaining sites. The procedure was repeated for apical, medial and basal stimulation sites, stimulating at subjective threshold and most comfortable levels. Responses were obtained in five out of six subjects and are discussed in terms of: reproducibility, quality, changes over time. Cochlear mapping provided repeatable data that gave interesting insights into the implanted cochlea. Further work is required to determine whether this approach could contribute to programme optimisation.

  20. Deep neural network architectures for forecasting analgesic response.

    PubMed

    Nickerson, Paul; Tighe, Patrick; Shickel, Benjamin; Rashidi, Parisa

    2016-08-01

    Response to prescribed analgesic drugs varies between individuals, and choosing the right drug/dose often involves a lengthy, iterative process of trial and error. Furthermore, a significant portion of patients experience adverse events such as post-operative urinary retention (POUR) during inpatient management of acute postoperative pain. To better forecast analgesic responses, we compared conventional machine learning methods with modern neural network architectures to gauge their effectiveness at forecasting temporal patterns of postoperative pain and analgesic use, as well as predicting the risk of POUR. Our results indicate that simpler machine learning approaches might offer superior results; however, all of these techniques may play a promising role for developing smarter post-operative pain management strategies.

  1. Limbic irritability and chaotic neural response during conflicting stroop task in the patients with unipolar depression.

    PubMed

    Bob, P; Susta, M; Procházková-Vecerová, A; Kukleta, M; Pavlát, J; Jagla, F; Raboch, J

    2006-01-01

    According to recent findings activation of anterior cingulate cortex (ACC) is related to detecting cognitive conflict. This conflict related activation elicits autonomic responses which can be assessed by psychophysiological measures such as heart rate variability calculated as beat to beat R-R intervals (RRI). Recent findings in neuroscience also suggest that cognitive conflict is related to specific nonlinear chaotic changes of the signal generated by neural systems. The present study used Stroop word-color test as an experimental approach to psychophysiological study of cognitive conflict in connection with RRI measurement, psychometric measurement of limbic irritability (LSCL-33), depression (BDI-II) and calculation of largest Lyapunov exponents in nonlinear data analysis of RRI time series. Significant correlation 0.61 between largest Lyapunov exponents and LSCL-33 found in this study indicate that a defect of neural inhibition during conflicting Stroop task is closely related to limbic irritability. Because limbic irritability is probably closely related to epileptiform abnormalities in the temporolimbic structures, this result might represent useful instrument for indication of anticonvulsant treatment in depressive patients who are resistant to antidepressant medication.

  2. Attention enhances contrast appearance via increased input baseline of neural responses

    PubMed Central

    Cutrone, Elizabeth K.; Heeger, David J.; Carrasco, Marisa

    2014-01-01

    Covert spatial attention increases the perceived contrast of stimuli at attended locations, presumably via enhancement of visual neural responses. However, the relation between perceived contrast and the underlying neural responses has not been characterized. In this study, we systematically varied stimulus contrast, using a two-alternative, forced-choice comparison task to probe the effect of attention on appearance across the contrast range. We modeled performance in the task as a function of underlying neural contrast-response functions. Fitting this model to the observed data revealed that an increased input baseline in the neural responses accounted for the enhancement of apparent contrast with spatial attention. PMID:25549920

  3. Relation between abnormal patterns of muscle activation and response to common peroneal nerve stimulation in hemiplegia

    PubMed Central

    Burridge, J; McLellan, D

    2000-01-01

    OBJECTIVE—To investigate the relation between response to common peroneal nerve stimulation, timed to the swing phase of walking, and abnormal ankle movement and muscle activation patterns.
METHOD—Eighteen patients who took part had a drop foot and had had a stroke at least 6 months before the study Twelve age matched normal subjects were also studied. Response to stimulation was measured by changes in the speed and effort of walking when the stimulator was used. Speed was measured over 10 m and effort by the physiological cost index. Abnormal ankle movement and muscle activation were measured in a rig by ability to follow a tracking signal moving sinusoidally at either 1 or 2 Hz, resistance to passive movement, and EMG activity during both passive and active movements. Indices were derived to define EMG response to passive stretch, coactivation, and ability to activate muscles appropriately during active movement
RESULTS—Different mechanisms underlying the drop foot were seen. Results showed that patients who had poor control of ankle movement and spasticity, demonstrated by stretch reflex and coactivation, were more likely to respond well to stimulation. Those with mechanical resistance to passive movement and with normal muscle activation responded less well.
CONCLUSIONS—The results support the hypothesis that stimulation of the common peroneal nerve to elicit a contraction of the anterior tibial muscles also inhibits the antagonist calf muscles. The technique used may be useful in directing physiotherapy by indicating the underlying cause of the drop foot.

 PMID:10945810

  4. CA1-specific deletion of NMDA receptors induces abnormal renewal of a learned fear response.

    PubMed

    Hirsch, Silke J; Regmi, Nanda L; Birnbaum, Shari G; Greene, Robert W

    2015-11-01

    CA1 hippocampal N-methyl-d-aspartate-receptors (NMDARs) are necessary for contextually related learning and memory processes. Extinction, a form of learning, has been shown to require intact hippocampal NMDAR signalling. Renewal of fear expression can occur after fear extinction training, when the extinguished fear stimulus is presented in an environmental context different from the training context and thus, renewal is dependent on contextual memory. In this study, we show that a Grin1 knock-out (loss of the essential NR1 subunit for the NMDAR) restricted to the bilateral CA1 subfield of the dorsal hippocampus does not affect acquisition of learned fear, but does attenuate extinction of a cued fear response even when presented in the extinction-training context. We propose that failure to remember the (safe) extinction context is responsible for the abnormal fear response and suggest it is a dysfunctional renewal. The results highlight the difference in outcome of extinguished fear memory resulting from a partial rather than complete loss of function of the hippocampus and suggest a potential mechanism for abnormally increased fear expression in PTSD.

  5. Adolescents' behavioral and neural responses to e-cigarette advertising.

    PubMed

    Chen, Yvonnes; Fowler, Carina H; Papa, Vlad B; Lepping, Rebecca J; Brucks, Morgan G; Fox, Andrew T; Martin, Laura E

    2017-04-11

    Although adolescents are a group heavily targeted by the e-cigarette industry, research in cue-reactivity has not previously examined adolescents' behavioral and neural responses to e-cigarette advertising. This study addressed this gap through two experiments. In Experiment One, adult traditional cigarette smokers (n = 41) and non-smokers (n = 41) answered questions about e-cigarette and neutral advertising images. The 40 e-cigarette advertising images that most increased desire to use the product were matched to 40 neutral advertising images with similar content. In Experiment Two, the 80 advertising images selected in Experiment One were presented to adolescents (n = 30) during an functional magnetic resonance imaging brain scan. There was a range of traditional cigarette smoking across the sample with some adolescents engaging in daily smoking and others who had never smoked. Adolescents self-reported that viewing the e-cigarette advertising images increased their desire to smoke. Additionally, all participants regardless of smoking statuses showed significantly greater brain activation to e-cigarette advertisements in areas associated with cognitive control (left middle frontal gyrus), reward (right medial frontal gyrus), visual processing/attention (left lingual gyrus/fusiform gyrus, right inferior parietal lobule, left posterior cingulate, left angular gyrus) and memory (right parahippocampus, left insula). Further, an exploratory analysis showed that compared with age-matched non-smokers (n = 7), adolescent smokers (n = 7) displayed significantly greater neural activation to e-cigarette advertising images in the left inferior temporal gyrus/fusiform gyrus, compared with their responses to neutral advertising images. Overall, participants' brain responses to e-cigarette advertisements suggest a need to further investigate the long-run impact of e-cigarette advertising on adolescents.

  6. Primary prevention of neural-tube defects and some other congenital abnormalities by folic acid and multivitamins: history, missed opportunity and tasks.

    PubMed

    Czeizel, Andrew E; Bártfai, Zoltán; Bánhidy, Ferenc

    2011-08-01

    The history of intervention trials of periconception folic acid with multivitamin and folic acid supplementation in women has shown a recent breakthrough in the primary prevention of structural birth defects, namely neural-tube defects and some other congenital abnormalities. Recently, some studies have demonstrated the efficacy of this new method in reducing congenital abnormalities with specific origin; for example, in the offspring of diabetic and epileptic mothers, and in pregnancy with high fever. The benefits and drawbacks of four possible uses of periconception folate/folic acid and multivitamin supplementation are discussed: we believe there has been a missed opportunity to implement this preventive approach in medical practice. The four methods are as follows: (i) dietary intake of folate and other vitamins, (ii) periconception folic acid/multivitamin supplementation, (iii) food fortification with folic acid, and (iv) the combination of oral contraceptives with 6S-5-methytetrahydrofolate ('folate').

  7. Abnormal epigenetic regulation of the gene expression levels of Wnt2b and Wnt7b: Implications for neural tube defects.

    PubMed

    Bai, Baoling; Chen, Shuyuan; Zhang, Qin; Jiang, Qian; Li, Huili

    2016-01-01

    The association between Wnt genes and neural tube defects (NTDs) is recognized, however, it remains to be fully elucidated. Our previous study demonstrated that epigenetic mechanisms are affected in human NTDs. Therefore, the present study aimed to evaluate whether Wnt2b and Wnt7b are susceptible to abnormal epigenetic modification in NTDs, using chromatin immunoprecipitation assays to evaluate histone enrichments and the MassARRAY platform to detect the methylation levels of target regions within Wnt genes. The results demonstrated that the transcriptional activities of Wnt2b and Wnt7b were abnormally upregulated in mouse fetuses with NTDs and, in the GC‑rich promoters of these genes, histone 3 lysine 4 (H3K4) acetylation was enriched, whereas H3K27 trimethylation was reduced. Furthermore, several CpG sites in the altered histone modification of target regions were significantly hypomethylated. The present study also detected abnormal epigenetic modifications of these Wnt genes in human NTDs. In conclusion, the present study detected abnormal upregulation in the levels of Wnt2b and Wnt7b, and hypothesized that the alterations may be due to the ectopic opening of chromatin structure. These results improve understanding of the dysregulation of epigenetic modification of Wnt genes in NTDs.

  8. The Neural Basis of Responsibility Attribution in Decision-Making

    PubMed Central

    Li, Peng; Shen, Yue; Sui, Xue; Chen, Changming; Feng, Tingyong; Li, Hong; Holroyd, Clay

    2013-01-01

    Social responsibility links personal behavior with societal expectations and plays a key role in affecting an agent’s emotional state following a decision. However, the neural basis of responsibility attribution remains unclear. In two previous event-related brain potential (ERP) studies we found that personal responsibility modulated outcome evaluation in gambling tasks. Here we conducted a functional magnetic resonance imaging (fMRI) study to identify particular brain regions that mediate responsibility attribution. In a context involving team cooperation, participants completed a task with their teammates and on each trial received feedback about team success and individual success sequentially. We found that brain activity differed between conditions involving team success vs. team failure. Further, different brain regions were associated with reinforcement of behavior by social praise vs. monetary reward. Specifically, right temporoparietal junction (RTPJ) was associated with social pride whereas dorsal striatum and dorsal anterior cingulate cortex (ACC) were related to reinforcement of behaviors leading to personal gain. The present study provides evidence that the RTPJ is an important region for determining whether self-generated behaviors are deserving of praise in a social context. PMID:24224053

  9. Neural response to emotional stimuli during experimental human endotoxemia.

    PubMed

    Kullmann, Jennifer S; Grigoleit, Jan-Sebastian; Lichte, Philipp; Kobbe, Philipp; Rosenberger, Christina; Banner, Christina; Wolf, Oliver T; Engler, Harald; Oberbeck, Reiner; Elsenbruch, Sigrid; Bingel, Ulrike; Forsting, Michael; Gizewski, Elke R; Schedlowski, Manfred

    2013-09-01

    Increases in peripheral cytokines during acute inflammation may affect various neuropsychological functions. The aim of this functional magnetic resonance imaging (fMRI) study was to investigate the effects of acute endotoxemia on mood and the neural response to emotionally aversive visual stimuli in healthy human subjects. In a double-blind, randomized crossover study, 18 healthy males received a bolus injection of bacterial lipopolysaccharide (LPS; 0.4 ng/kg) or saline. Plasma levels of pro- and anti-inflammatory cytokines and cortisol as well as mood ratings were analyzed together with the blood-oxygen-level dependent (BOLD) response during the presentation of aversive versus neutral pictures. Endotoxin administration induced pronounced transient increases in plasma levels of TNF-α, IL-1ra, IL-6, IL-10, and cortisol. Positive mood was decreased and state anxiety increased. In addition, activation of right inferior orbitofrontal cortex (OFC) in response to emotional visual stimuli was significantly increased in the LPS condition. Increased prefrontal activation during the presentation of emotional material may reflect enhanced cognitive regulation of emotions as an adaptive response during an acute inflammation. These findings may have implications for the putative role of inflammatory processes in the pathophysiology of depression.

  10. Intraoperative Neural Response Telemetry and Neural Recovery Function: a Comparative Study between Adults and Children

    PubMed Central

    Carvalho, Bettina; Hamerschmidt, Rogerio; Wiemes, Gislaine

    2014-01-01

    Introduction Neural response telemetry (NRT) is a method of capturing the action potential of the distal portion of the auditory nerve in cochlear implant (CI) users, using the CI itself to elicit and record the answers. In addition, it can also measure the recovery function of the auditory nerve (REC), that is, the refractory properties of the nerve. It is not clear in the literature whether the responses from adults are the same as those from children. Objective To compare the results of NRT and REC between adults and children undergoing CI surgery. Methods Cross-sectional, descriptive, and retrospective study of the results of NRT and REC for patients undergoing IC at our service. The NRT is assessed by the level of amplitude (microvolts) and REC as a function of three parameters: A (saturation level, in microvolts), t0 (absolute refractory period, in seconds), and tau (curve of the model function), measured in three electrodes (apical, medial, and basal). Results Fifty-two patients were evaluated with intraoperative NRT (26 adults and 26 children), and 24 with REC (12 adults and 12 children). No statistically significant difference was found between intraoperative responses of adults and children for NRT or for REC's three parameters, except for parameter A of the basal electrode. Conclusion The results of intraoperative NRT and REC were not different between adults and children, except for parameter A of the basal electrode. PMID:25992145

  11. Empathy and stress related neural responses in maternal decision making

    PubMed Central

    Ho, S. Shaun; Konrath, Sara; Brown, Stephanie; Swain, James E.

    2014-01-01

    Mothers need to make caregiving decisions to meet the needs of children, which may or may not result in positive child feedback. Variations in caregivers' emotional reactivity to unpleasant child-feedback may be partially explained by their dispositional empathy levels. Furthermore, empathic response to the child's unpleasant feedback likely helps mothers to regulate their own stress. We investigated the relationship between maternal dispositional empathy, stress reactivity, and neural correlates of child feedback to caregiving decisions. In Part 1 of the study, 33 female participants were recruited to undergo a lab-based mild stressor, the Social Evaluation Test (SET), and then in Part 2 of the study, a subset of the participants, 14 mothers, performed a Parenting Decision Making Task (PDMT) in an fMRI setting. Four dimensions of dispositional empathy based on the Interpersonal Reactivity Index were measured in all participants—Personal Distress, Empathic Concern, Perspective Taking, and Fantasy. Overall, we found that the Personal Distress and Perspective Taking were associated with greater and lesser cortisol reactivity, respectively. The four types of empathy were distinctly associated with the negative (vs. positive) child feedback activation in the brain. Personal Distress was associated with amygdala and hypothalamus activation, Empathic Concern with the left ventral striatum, ventrolateral prefrontal cortex (VLPFC), and supplemental motor area (SMA) activation, and Fantasy with the septal area, right SMA and VLPFC activation. Interestingly, hypothalamus-septal coupling during the negative feedback condition was associated with less PDMT-related cortisol reactivity. The roles of distinct forms of dispositional empathy in neural and stress responses are discussed. PMID:24971049

  12. Respiratory responses to cold water immersion: neural pathways, interactions, and clinical consequences awake and asleep.

    PubMed

    Datta, Avijit; Tipton, Michael

    2006-06-01

    The ventilatory responses to immersion and changes in temperature are reviewed. A fall in skin temperature elicits a powerful cardiorespiratory response, termed "cold shock," comprising an initial gasp, hypertension, and hyperventilation despite a profound hypocapnia. The physiology and neural pathways of this are examined with data from original studies. The respiratory responses to skin cooling override both conscious and other autonomic respiratory controls and may act as a precursor to drowning. There is emerging evidence that the combination of the reestablishment of respiratory rhythm following apnea, hypoxemia, and coincident sympathetic nervous and cyclic vagal stimulation appears to be an arrhythmogenic trigger. The potential clinical implications of this during wakefulness and sleep are discussed in relation to sudden death during immersion, underwater birth, and sleep apnea. A drop in deep body temperature leads to a slowing of respiration, which is more profound than the reduced metabolic demand seen with hypothermia, leading to hypercapnia and hypoxia. The control of respiration is abnormal during hypothermia, and correction of the hypoxia by inhalation of oxygen may lead to a further depression of ventilation and even respiratory arrest. The immediate care of patients with hypothermia needs to take these factors into account to maximize the chances of a favorable outcome for the rescued casualty.

  13. Diversity of neural responses in the brainstem during smooth pursuit eye movements constrains the circuit mechanisms of neural integration

    PubMed Central

    Joshua, Mati; Medina, Javier F.; Lisberger, Stephen G.

    2013-01-01

    Neural integration converts transient events into sustained neural activity. In the smooth pursuit eye movement system, neural integration is required to convert cerebellar output into the sustained discharge of extraocular motoneurons. We recorded the expression of integration in the time-varying firing rates of cerebellar and brainstem neurons in the monkey during pursuit of step-ramp target motion. Electrical stimulation with single shocks in the cerebellum identified brainstem neurons that are monosynaptic targets of inhibition from the cerebellar floccular complex. They discharge in relation to eye acceleration, eye velocity, and eye position, with a stronger acceleration signal than found in most other brainstem neurons. The acceleration and velocity signals can be accounted for by opponent contributions from the two sides of the cerebellum, without integration; the position signal implies participation in the integrator. Other neurons in the vestibular nucleus show a wide range of blends of signals related to eye velocity and eye position, reflecting different stages of integration. Neurons in the Abducens nucleus discharge homogeneously in relation mainly to eye position, and reflect almost perfect integration of the cerebellar outputs. Average responses of neural populations and the diverse individual responses of large samples of individual neurons are reproduced by a hierarchical neural circuit based on a model suggested the anatomy and physiology of the larval zebrafish brainstem. The model uses a combination of feed-forward and feedback connections to support a neural circuit basis for integration in monkeys and other species. PMID:23575860

  14. The effect of verbal context on olfactory neural responses.

    PubMed

    Bensafi, Moustafa; Croy, Ilona; Phillips, Nicola; Rouby, Catherine; Sezille, Caroline; Gerber, Johannes; Small, Dana M; Hummel, Thomas

    2014-03-01

    Odor names refer usually to "source" object categories. For example, the smell of rose is often described with its source category (flower). However, linguistic studies suggest that odors can also be named with labels referring to categories of "practices". This is the case when rose odor is described with a verbal label referring to its use in fragrance practices ("body lotion," cosmetic for example). It remains unknown whether naming an odor by its practice category influences olfactory neural responses differently than that observed when named with its source category. The aim of this study was to investigate this question. To this end, functional MRI was used in a within-subjects design comparing brain responses to four different odors (peach, chocolate, linden blossom, and rose) under two conditions whereby smells were described either (1) with their source category label (food and flower) or (2) with a practice category label (body lotion). Both types of labels induced activations in secondary olfactory areas (orbitofrontal cortex), whereas only the source label condition induced activation in the cingulate cortex and the insula. In summary, our findings offer a new look at olfactory perception by indicating differential brain responses depending on whether odors are named according to their source or practice category.

  15. Neural Correlates of Response Inhibition in Pediatric Bipolar Disorder

    PubMed Central

    Chang, Kiki D.; Mazaika, Paul; Garrett, Amy; Adleman, Nancy; Kelley, Ryan; Howe, Meghan; Reiss, Allan

    2010-01-01

    Abstract Objectives Pediatric bipolar disorder is characterized by core deficits in mood and executive function and commonly co-occurs with attention-deficit/hyperactivity disorder (ADHD). We aimed to examine response inhibition in this population, as an element of executive function, which, if aberrant, may interfere with learning and information processing. Methods Children (9–18 years) with bipolar I or II disorder (BD, n = 26) and age, gender, and intelligence quotient (IQ) comparable healthy children (HC, n = 22) without any psychopathology were given a standardized Go/NoGo computerized task measuring response inhibition. A whole-brain functional magnetic resonance imaging (MRI) group analysis was performed using statistical parametric mapping software (SPM2) for comparing NoGo to Go epochs. Results There were no statistically significant group differences between groups in age, gender, or ethnicity. The BD group had high rates of co-morbid disorders, including 81% with ADHD, 62% with oppositional defiant disorder (ODD), and 46% with anxiety disorders. This BD group had fewer correct responses on Go (84% vs. 96%, T[46] = 3.35, p = 0.002) and overall (85% vs. 94%, T[46] = 4.12, p = 0.0002) trials as compared to the HC group. However, there were no statistically significant group differences in response inhibition on NoGo trials (p = 0.11). In the NoGo−Go contrast, the BD group showed increased neural activation in the right dorsolateral prefrontal cortex (DLPFC) compared to HC (T[46] = 4.21, p < 0.001). Conclusions During accurate NoGo but impaired Go trial performance, children with BD showed increased right DLPFC activation versus controls, suggesting increased recruitment of executive control regions for accurate response inhibition. Studies relating these results to mood regulation in pediatric BD are warranted. PMID:20166792

  16. Abnormal Brain Responses to Action Observation in Complex Regional Pain Syndrome.

    PubMed

    Hotta, Jaakko; Saari, Jukka; Koskinen, Miika; Hlushchuk, Yevhen; Forss, Nina; Hari, Riitta

    2017-03-01

    Patients with complex regional pain syndrome (CRPS) display various abnormalities in central motor function, and their pain is intensified when they perform or just observe motor actions. In this study, we examined the abnormalities of brain responses to action observation in CRPS. We analyzed 3-T functional magnetic resonance images from 13 upper limb CRPS patients (all female, ages 31-58 years) and 13 healthy, age- and sex-matched control subjects. The functional magnetic resonance imaging data were acquired while the subjects viewed brief videos of hand actions shown in the first-person perspective. A pattern-classification analysis was applied to characterize brain areas where the activation pattern differed between CRPS patients and healthy subjects. Brain areas with statistically significant group differences (q < .05, false discovery rate-corrected) included the hand representation area in the sensorimotor cortex, inferior frontal gyrus, secondary somatosensory cortex, inferior parietal lobule, orbitofrontal cortex, and thalamus. Our findings indicate that CRPS impairs action observation by affecting brain areas related to pain processing and motor control.

  17. Abnormal auditory forward masking pattern in the brainstem response of individuals with Asperger syndrome

    PubMed Central

    Källstrand, Johan; Olsson, Olle; Nehlstedt, Sara Fristedt; Sköld, Mia Ling; Nielzén, Sören

    2010-01-01

    Abnormal auditory information processing has been reported in individuals with autism spectrum disorders (ASD). In the present study auditory processing was investigated by recording auditory brainstem responses (ABRs) elicited by forward masking in adults diagnosed with Asperger syndrome (AS). Sixteen AS subjects were included in the forward masking experiment and compared to three control groups consisting of healthy individuals (n = 16), schizophrenic patients (n = 16) and attention deficit hyperactivity disorder patients (n = 16), respectively, of matching age and gender. The results showed that the AS subjects exhibited abnormally low activity in the early part of their ABRs that distinctly separated them from the three control groups. Specifically, wave III amplitudes were significantly lower in the AS group than for all the control groups in the forward masking condition (P < 0.005), which was not the case in the baseline condition. Thus, electrophysiological measurements of ABRs to complex sound stimuli (eg, forward masking) may lead to a better understanding of the underlying neurophysiology of AS. Future studies may further point to specific ABR characteristics in AS individuals that separate them from individuals diagnosed with other neurodevelopmental diseases. PMID:20628629

  18. Social norms shift behavioral and neural responses to foods.

    PubMed

    Nook, Erik C; Zaki, Jamil

    2015-07-01

    Obesity contributes to 2.8 million deaths annually, making interventions to promote healthy eating critical. Although preliminary research suggests that social norms influence eating behavior, the underlying psychological and neural mechanisms of such conformity remain unexplored. We used fMRI to investigate whether group norms shift individuals' preferences for foods at both behavioral and neural levels. Hungry participants rated how much they wanted to eat a series of healthy and unhealthy foods and, after each trial, saw ratings that ostensibly represented their peers' preferences. This feedback was manipulated such that peers appeared to prefer each food more than, less than, or as much as participants themselves. After a delay, participants rerated each food. Participants' second ratings shifted to resemble group norms. Initial consensus, as compared to disagreement, with peers produced activity in the nucleus accumbens, a region associated with reward prediction errors. Furthermore, the strength of this activity predicted the extent to which participants' ratings conformed to peer ratings, suggesting that the value associated with consensus drives social influence. Ventromedial prefrontal cortex (vMPFC), a region associated with value computation, initially responded more strongly to unhealthy, as compared to healthy, foods. However, this effect was "overwritten" by group norms. After individuals learned their peers' preferences, vMPFC responses tracked the popularity, but not the healthfulness, of foods. Furthermore, changes in vMPFC activity tracked social influence over behavioral ratings. These data provide evidence that group norms can shift food preferences, supporting the use of norms-based interventions to promote healthy eating.

  19. A neural mass model of spectral responses in electrophysiology

    PubMed Central

    Moran, R.J.; Kiebel, S.J.; Stephan, K.E.; Reilly, R.B.; Daunizeau, J.; Friston, K.J.

    2007-01-01

    We present a neural mass model of steady-state membrane potentials measured with local field potentials or electroencephalography in the frequency domain. This model is an extended version of previous dynamic causal models for investigating event-related potentials in the time-domain. In this paper, we augment the previous formulation with parameters that mediate spike-rate adaptation and recurrent intrinsic inhibitory connections. We then use linear systems analysis to show how the model's spectral response changes with its neurophysiological parameters. We demonstrate that much of the interesting behaviour depends on the non-linearity which couples mean membrane potential to mean spiking rate. This non-linearity is analogous, at the population level, to the firing rate–input curves often used to characterize single-cell responses. This function depends on the model's gain and adaptation currents which, neurobiologically, are influenced by the activity of modulatory neurotransmitters. The key contribution of this paper is to show how neuromodulatory effects can be modelled by adding adaptation currents to a simple phenomenological model of EEG. Critically, we show that these effects are expressed in a systematic way in the spectral density of EEG recordings. Inversion of the model, given such non-invasive recordings, should allow one to quantify pharmacologically induced changes in adaptation currents. In short, this work establishes a forward or generative model of electrophysiological recordings for psychopharmacological studies. PMID:17632015

  20. The association between anger-related personality trait and cardiac autonomic response abnormalities in elderly subjects.

    PubMed

    Narita, Kosuke; Murata, Tetsuhito; Takahashi, Tetsuya; Hamada, Toshihiko; Kosaka, Hirotaka; Yoshida, Haruyoshi; Wada, Yuji

    2007-09-01

    Cardiac autonomic response abnormality associated with trait anger has been recognized to elevate blood pressure in daily life, leading to atherosclerotic progression and cardiovascular disease. To clarify the relationship between anger-related personality traits and cardiac autonomic response in healthy elderly subjects, 54 volunteers consisting of 30 male (mean age 62.2+/-5.4) and 24 female (mean age 58.4+/-4.6) subjects underwent testing of heart rate variability (HRV) with head-up tilt. For the evaluation of trait anger, we used a questionnaire corresponding to the trait anger score taken from the State and Trait Anger Expression Inventory. Furthermore, we measured carotid intima-medial thickness (IMT) to evaluate atherosclerotic progression in subjects with anger trait. In female subjects, higher trait anger was positively associated with elevated carotid IMT and the suppression of HRV vagal attenuation from the supine to head-up position, and negatively associated with the HRV sympathetic activity in the head-up position and also with the HRV sympathetic response from the supine to head-up position. In male subjects, trait anger was not significantly associated with carotid IMT or any HRV component with or without head-up tilt testing. We conclude that a simple noninvasive measure, short-term HRV with head-up tilt testing, could be a useful method to investigate the association between cardiac autonomic imbalance and increased risk of atherosclerosis associated with trait anger in healthy elderly subjects.

  1. Mutations of the XLRS1 gene cause abnormalities of photoreceptor as well as inner retinal responses of the ERG.

    PubMed

    Bradshaw, K; George, N; Moore, A; Trump, D

    1999-01-01

    Intensity-series rod and cone ERGs were recorded in 19 patients with XLRS and 26 control eyes. All patients were examined by one ophthalmologist and diagnosed on the basis of fundus appearance and evidence of the disease in other males in the same family. Mutations in the XLRS1 gene have been identified in 15 of the patients. Dark-adapted ERGs were significantly different from controls for all test conditions and for both a-wave and b-wave responses. Abnormalities were detectable in all patients but there was considerable variation in the severity of abnormality. One third of the patients had the dark-adapted 'negative-wave' response typically associated with inner retinal disorder, but about one third showed only mild depression of the b-wave while the remainder had abnormally low a-waves in addition to depressed b-waves. Light-adapted responses were also affected and both a-wave and b-wave responses differed significantly from controls, but the 'negative-wave' response was not seen in any patient. The severity of the ERG abnormality did not correlate with the classification of fundus appearance or patient age suggesting that retinal function is relatively stable throughout life. The severity of ERG abnormalities did not correlate with the type of mutation and responses could differ between affected males within the same family. These results indicate considerable heterogeneity of ERG response without clinical, age or genetic correlate. The abnormal a-wave responses indicate that photoreceptor as well as inner retinal layer function may be affected in XLRS, at least in some patients.

  2. Sex differences in associations between cannabis craving and neural responses to cannabis cues: Implications for treatment.

    PubMed

    Wetherill, Reagan R; Jagannathan, Kanchana; Hager, Nathan; Childress, Anna Rose; Franklin, Teresa R

    2015-08-01

    Preclinical and clinical research indicates that there are sex differences in how men and women initiate, progress, respond to, and withdraw from cannabis use; however, neurophysiological differences, such as neural responses to cannabis cues, are not well understood. Using functional MRI and an event-related blood oxygen level-dependent backward-masking task, we compared neural responses to backward-masked cannabis cues to neutral cues in treatment-seeking, cannabis-dependent adults (N = 44; 27 males) and examined whether sex differences exist. In addition, functional MRI findings were correlated with cannabis craving. Backward-masked cannabis cues elicited greater neural responses than neutral cues in reward-related brain regions, including the striatum, hippocampus/amygdala, insula, anterior cingulate cortex, and lateral orbitofrontal cortex, p < .01, k > 121 voxels. Although no significant sex differences in neural responses to cannabis cues emerged, women showed a positive correlation between neural responses to cannabis cues in the bilateral insula and cannabis craving and an inverse correlation between neural responses to cannabis cues in the left lateral orbitofrontal cortex and cannabis craving. Men, however, showed a positive correlation between neural responses to cannabis cues in the striatum and cannabis craving. Given that cues and craving are important triggers and the focus on many behavioral treatment approaches, these findings suggest that treatment-seeking, cannabis-dependent men and women may benefit from sex-specific and tailored cannabis use disorder treatments.

  3. Alteration of antioxidant defense status precedes humoral immune response abnormalities in macrosomia

    PubMed Central

    Haddouche, Mustapha; Aribi, Mourad; Moulessehoul, Soraya; Smahi, Mohammed Chems-Eddine Ismet; Lammani, Mohammed; Benyoucef, Mohammed

    2011-01-01

    Summary Background This study aimed to investigate whether the anomalies affecting the antioxidant and humoral immune defenses could start at birth and to check whether the decrease in antioxidant defenses may precede the immune abnormalities in macrosomic newborns. Material/Methods Thirty macrosomic and 30 sex-matched control newborns were recruited for a retrospective case-control study at the Maghnia Maternity Hospital of Tlemcen Department (Algeria). Results The serum IgG levels were similar in both groups. However, plasma ORAC, albumin, vitamin E, SOD, CAT and GSH-Px levels were significantly decreased in macrosomic as compared to control newborns, yet no difference was observed after adjustment for weight. Additionally, serum concentrations of complement C3, MDA and XO were significantly higher in macrosomic as compared to controls before adjustment for weight. Moreover, macrosomia was significantly associated with high levels of complement C3 (OR=8, p=0.002); whereas no association with those of IgG was observed (OR<1, p>0.05). Furthermore, macrosomia was significantly associated with low levels of ORAC (OR=4.96, p=0.027), vitamin E (OR=4.5, p=0.018), SOD (OR=6.88, p=0.020) and CAT (OR=5.67, p=0.017), and with high levels of MDA (OR=10.29, p=0.005). Conclusions Abnormalities of the humoral defense system in excessive weight could be preceded by alterations of the anti-oxidative defense and by inflammatory response and activation of innate immunity at birth. Additionally, excessive weight could be a potential factor contributing to decreased anti-oxidative capacity and increased oxidative stress. PMID:22037745

  4. Genetically induced abnormal cranial development in human trisomy 18 with holoprosencephaly: comparisons with the normal tempo of osteogenic-neural development.

    PubMed

    Reid, Shaina N; Ziermann, Janine M; Gondré-Lewis, Marjorie C

    2015-07-01

    Craniofacial malformations are common congenital defects caused by failed midline inductive signals. These midline defects are associated with exposure of the fetus to exogenous teratogens and with inborn genetic errors such as those found in Down, Patau, Edwards' and Smith-Lemli-Opitz syndromes. Yet, there are no studies that analyze contributions of synchronous neurocranial and neural development in these disorders. Here we present the first in-depth analysis of malformations of the basicranium of a holoprosencephalic (HPE) trisomy 18 (T18; Edwards' syndrome) fetus with synophthalmic cyclopia and alobar HPE. With a combination of traditional gross dissection and state-of-the-art computed tomography, we demonstrate the deleterious effects of T18 caused by a translocation at 18p11.31. Bony features included a single developmentally unseparated frontal bone, and complete dual absence of the anterior cranial fossa and ethmoid bone. From a superior view with the calvarium plates removed, there was direct visual access to the orbital foramen and hard palate. Both the eyes and the pituitary gland, normally protected by bony structures, were exposed in the cranial cavity and in direct contact with the brain. The middle cranial fossa was shifted anteriorly, and foramina were either missing or displaced to an abnormal location due to the absence or misplacement of its respective cranial nerve (CN). When CN development was conserved in its induction and placement, the respective foramen developed in its normal location albeit with abnormal gross anatomical features, as seen in the facial nerve (CNVII) and the internal acoustic meatus. More anteriorly localized CNs and their foramina were absent or heavily disrupted compared with posterior ones. The severe malformations exhibited in the cranial fossae, orbital region, pituitary gland and sella turcica highlight the crucial involvement of transcription factors such as TGIF, which is located on chromosome 18 and contributes

  5. Neural responses to perceiving suffering in humans and animals.

    PubMed

    Franklin, Robert G; Nelson, Anthony J; Baker, Michelle; Beeney, Joseph E; Vescio, Theresa K; Lenz-Watson, Aurora; Adams, Reginald B

    2013-01-01

    The human ability to perceive and understand others' suffering is critical to reinforcing and maintaining our social bonds. What is not clear, however, is the extent to which this generalizes to nonhuman entities. Anecdotal evidence indicates that people may engage in empathy-like processes when observing suffering nonhuman entities, but psychological research suggests that we more readily empathize with those to whom we are closer and more similar. In this research, we examined neural responses in participants while they were presented with pictures of human versus dog suffering. We found that viewing human and animal suffering led to large overlapping regions of activation previously implicated in empathic responding to suffering, including the anterior cingulate gyrus and anterior insula. Direct comparisons of viewing human and animal suffering also revealed differences such that human suffering yielded significantly greater medial prefrontal activation, consistent with high-level theory of mind, whereas animal suffering yielded significantly greater parietal and inferior frontal activation, consistent with more semantic evaluation and perceptual simulation.

  6. Seismic response modeling of multi-story buildings using neural networks

    NASA Astrophysics Data System (ADS)

    Conte, Joel P.; Durrani, Ahmad J.; Shelton, Robert O.

    1994-05-01

    A neural network based approach to model the seismic response of multi-story frame buildings is presented. The seismic response of frames is emulated using multi-layer feedforward neural networks with a backpropagation learning algorithm. Actual earthquake accelerograms and corresponding structural response obtained from analytical models of buildings are used in training the neural networks. The application of the neural network model is demonstrated by studying one to six story high building frames subjected to seismic base excitation. Furthermore, the learning ability of the network is examined for the case of multiple inputs where lateral forces at floor levels are included simultaneously with the base excitation. The effects of the network parameters on learning and accuracy of predictions are discussed. Based on this study, it is found that appropriately configured neural network models can successfully learn and simulate the linear elastic dynamic behavior of multi-story buildings.

  7. Application of Neural Networks to Wind tunnel Data Response Surface Methods

    NASA Technical Reports Server (NTRS)

    Lo, Ching F.; Zhao, J. L.; DeLoach, Richard

    2000-01-01

    The integration of nonlinear neural network methods with conventional linear regression techniques is demonstrated for representative wind tunnel force balance data modeling. This work was motivated by a desire to formulate precision intervals for response surfaces produced by neural networks. Applications are demonstrated for representative wind tunnel data acquired at NASA Langley Research Center and the Arnold Engineering Development Center in Tullahoma, TN.

  8. Depression Risk Predicts Blunted Neural Responses to Gains and Enhanced Responses to Losses in Healthy Children

    PubMed Central

    Luking, Katherine R.; Pagliaccio, David; Luby, Joan L.; Barch, Deanna M.

    2016-01-01

    Objective Maternal major depressive disorder (MDD) increases risk for MDD and predicts reduced reward responding in adolescent offspring. However, it is unclear whether alterations in neural response to reward can be detected in school-aged children at high risk prior to the typical increase in reward response observed in adolescence. Method To assess relationships between neural response to gain/loss feedback, MDD risk, and child depressive symptoms, forty-seven psychiatrically healthy 7–10-year-old children (16 at high-risk given maternal MDD) completed questionnaires and a functional magnetic resonance imaging (fMRI) card-guessing game where candy was gained and lost. Results High-risk children showed both blunted response to gain and greater deactivation/reduced activation to loss within the ventral striatum and anterior insula. Within the striatum, risk-group differences in response to loss feedback were significantly larger than for gain, with greater deactivation to loss predicting risk-group status above and beyond blunted gain activation. Anhedonia was related to reduced deactivation to loss (i.e. reduced sensitivity to loss), while negative mood was related to enhanced deactivation to loss (i.e. enhanced sensitivity to loss) in the ventral striatum. Conclusion High-risk children showed blunted ventral striatal activation to gain feedback, but ventral striatal deactivation to loss was a stronger predictor of MDD risk. Further, relationships between response to loss and elevated depressive symptoms within the ventral striatum and cingulate differed depending on the type of depressive symptom. Together these results highlight the potentially important role of response to loss of reward in childhood risk for depression. PMID:27015724

  9. Proportionate Responses to Life Events Influence Clinicians' Judgments of Psychological Abnormality

    ERIC Educational Resources Information Center

    Kim, Nancy S.; Paulus, Daniel J.; Gonzalez, Jeffrey S.; Khalife, Danielle

    2012-01-01

    Psychological abnormality is a fundamental concept in the "Diagnostic and Statistical Manual of Mental Disorders" ("DSM-IV-TR"; American Psychiatric Association, 2000) and in all clinical evaluations. How do practicing clinical psychologists use the context of life events to judge the abnormality of a person's current behaviors? The appropriate…

  10. Longer latency of sensory response to intravenous odor injection predicts olfactory neural disorder

    PubMed Central

    Kikuta, Shu; Matsumoto, Yu; Kuboki, Akihito; Nakayama, Tsuguhisa; Asaka, Daiya; Otori, Nobuyoshi; Kojima, Hiromi; Sakamoto, Takashi; Akinori, Kashio; Kanaya, Kaori; Ueha, Rumi; Kagoya, Ryoji; Nishijima, Hironobu; Toma-Hirano, Makiko; Kikkawa, Yayoi; Kondo, Kenji; Tsunoda, Koichi; Miyaji, Tempei; Yamaguchi, Takuhiro; Kataoka, Kazunori; Mori, Kensaku; Yamasoba, Tatsuya

    2016-01-01

    A near loss of smell may result from conductive and/or neural olfactory disorders. However, an olfactory test to selectively detect neural disorders has not been established. We investigated whether onset latency of sensory response to intravenous odor injection can detect neural disorders in humans and mice. We showed that longer preoperative onset latency of odor recognition to intravenous odor in patients with chronic rhinosinusitis predicted worse recovery of olfactory symptoms following sinus surgery. The onset latency of the olfactory sensory neuron (OSN) response to intravenous odor using synaptopHluorin signals from OSN axon terminals was delayed in mice with reduced numbers of OSNs (neural disorder) but not with increased mucus or blocked orthonasal pathways (conductive disorders). Moreover, the increase in onset latency correlated with the decrease in mature OSN numbers. Longer onset latency to intravenous odor injection is a useful biomarker for presence and severity of olfactory disorders with neural etiology. PMID:27734933

  11. Predicting the Probability of Abnormal Stimulated Growth Hormone Response in Children After Radiotherapy for Brain Tumors

    SciTech Connect

    Hua Chiaho; Wu Shengjie; Chemaitilly, Wassim; Lukose, Renin C.; Merchant, Thomas E.

    2012-11-15

    Purpose: To develop a mathematical model utilizing more readily available measures than stimulation tests that identifies brain tumor survivors with high likelihood of abnormal growth hormone secretion after radiotherapy (RT), to avoid late recognition and a consequent delay in growth hormone replacement therapy. Methods and Materials: We analyzed 191 prospectively collected post-RT evaluations of peak growth hormone level (arginine tolerance/levodopa stimulation test), serum insulin-like growth factor 1 (IGF-1), IGF-binding protein 3, height, weight, growth velocity, and body mass index in 106 children and adolescents treated for ependymoma (n = 72), low-grade glioma (n = 28) or craniopharyngioma (n = 6), who had normal growth hormone levels before RT. Normal level in this study was defined as the peak growth hormone response to the stimulation test {>=}7 ng/mL. Results: Independent predictor variables identified by multivariate logistic regression with high statistical significance (p < 0.0001) included IGF-1 z score, weight z score, and hypothalamic dose. The developed predictive model demonstrated a strong discriminatory power with an area under the receiver operating characteristic curve of 0.883. At a potential cutoff point of probability of 0.3 the sensitivity was 80% and specificity 78%. Conclusions: Without unpleasant and expensive frequent stimulation tests, our model provides a quantitative approach to closely follow the growth hormone secretory capacity of brain tumor survivors. It allows identification of high-risk children for subsequent confirmatory tests and in-depth workup for diagnosis of growth hormone deficiency.

  12. An item response theory integration of normal and abnormal personality scales.

    PubMed

    Samuel, Douglas B; Simms, Leonard J; Clark, Lee Anna; Livesley, W John; Widiger, Thomas A

    2010-01-01

    The Diagnostic and Statistical Manual of Mental Disorders (DSM–IV–TR) currently conceptualizes personality disorders (PDs) as categorical syndromes that are distinct from normal personality. However, an alternative dimensional viewpoint is that PDs are maladaptive expressions of general personality traits. The dimensional perspective postulates that personality pathology exists at a more extreme level of the latent trait than does general personality. This hypothesis was examined using item response theory analyses comparing scales from two personality pathology instruments—the Dimensional Assessment of Personality Pathology-Basic Questionnaire (DAPP-BQ; Livesley & Jackson, in press) and the Schedule for Nonadaptive and Adaptive Personality (SNAP; Clark, 1993; Clark, Simms, Wu, & Casillas, in press)—with scales from an instrument designed to assess normal range personality, the NEO Personality Inventory–Revised (NEO PI-R; Costa & McCrae, 1992). The results indicate that respective scales from these instruments assess shared latent constructs, with the NEO PI-R providing more information at the lower (normal) range and the DAPP-BQ and SNAP providing more information at the higher (abnormal) range. Nevertheless, the results also demonstrated substantial overlap in coverage. Implications of the findings are discussed with respect to the study and development of items that would provide specific discriminations along underlying trait continua.

  13. An exploratory investigation of abnormal pain response among preadolescent children in foster care.

    PubMed

    Tarren-Sweeney, Michael

    2010-01-01

    The present article describes a pattern of abnormal responses to pain (APR) among children in care, suggestive of pain insensitivity or failure to communicate felt pain. Exploratory analyses of caregiver-reported APR were conducted within a larger epidemiological study of 347 preadolescent children in foster and kinship care. APR items were generated from clinical assessment reports and a clinician survey, during development of a psychiatric rating scale for children in care. An APR construct was identified in factor analysis. Nine per cent of the sample had scores suggesting clinically meaningful APR, with a high level of corresponding psychological disturbance. Various analyses suggest the phenomenon may be a discrete, but integral component of complex, multifaceted psychopathology. Concurrent and retrospective measures of a large number of potential risk variables did not discriminate between APR scores and other estimates of psychopathology. However, moderate correlations between APR and ad hoc measures of impulsivity, dissociative behaviours, and inhibited-avoidant attachment difficulties suggest a number of hypothesized developmental mechanisms that might be explored in further studies.

  14. A neural model for compensation of sensory abnormalities in autism through feedback from a measure of global perception.

    PubMed

    Noriega, Gerardo

    2008-08-01

    Sensory abnormalities and weak central coherence (WCC), a processing bias for features and local information, are important characteristics associated with autism. This paper introduces a self-organizing map (SOM)-based computational model of sensory abnormalities in autism, and of a feedback system to compensate for them. Feedback relies on a measure of balance of coverage over four (sensory) domains. Different methods to compute this measure are discussed, as is the flexibility to configure the system using different control mechanisms. Statistically significant improvements throughout training are demonstrated for compensation of a simple (i.e., monotonically decreasing) hypersensitivity in one of the domains. Fine-tuning control parameters can lead to further gains, but a standard setup results in good performance. Significant improvements are also shown for complex hypersensitivities (i.e., increasing and decreasing through time) in two domains. Although naturally best suited to compensate hypersensitivities--stimuli filtering may mitigate neuron migration to a hypersensitive domain--the system is also shown to perform effectively when compensating hyposensitivities. With poor coverage balance in the model akin to poor global perception, WCC would be consistent with inadequate feedback, resulting in uncontrolled hyper- and/or hyposensitivities characteristic of autism, as seen in the topologies of the resulting SOMs.

  15. Gaze Direction Modulates the Relation between Neural Responses to Faces and Visual Awareness.

    PubMed

    Madipakkam, Apoorva Rajiv; Rothkirch, Marcus; Guggenmos, Matthias; Heinz, Andreas; Sterzer, Philipp

    2015-09-30

    Gaze direction and especially direct gaze is a powerful nonverbal cue that plays an important role in social interactions. Here we studied the neural mechanisms underlying the privileged access of direct gaze to visual awareness. We performed functional magnetic resonance imaging in healthy human volunteers who were exposed to faces with direct or averted gaze under continuous flash suppression, thereby manipulating their awareness of the faces. A gaze processing network comprising fusiform face area (FFA), superior temporal sulcus, amygdala, and intraparietal sulcus showed overall reduced neural responses when participants reported to be unaware of the faces. Interestingly, direct gaze elicited greater responses than averted gaze when participants were aware of the faces, but smaller responses when they were unaware. Additional between-subject correlation and single-trial analyses indicated that this pattern of results was due to a modulation of the relationship between neural responses and awareness by gaze direction: with increasing neural activation in the FFA, direct-gaze faces entered awareness more readily than averted-gaze faces. These findings suggest that for direct gaze, lower levels of neural activity are sufficient to give rise to awareness than for averted gaze, thus providing a neural basis for privileged access of direct gaze to awareness. Significance statement: Another person's eye gaze directed at oneself is a powerful social signal acting as a catalyst for further communication. Here, we studied the neural mechanisms underlying the prioritized access of direct gaze to visual awareness in healthy human volunteers and show that with increasing neural activation, direct-gaze faces enter awareness more readily than averted-gaze faces. This suggests that for a socially highly relevant cue like direct gaze, lower levels of neural activity are sufficient to give rise to awareness compared with averted gaze, possibly because the human brain is attuned

  16. Menstrual cycle effects on sympathetic neural responses to upright tilt.

    PubMed

    Fu, Qi; Okazaki, Kazunobu; Shibata, Shigeki; Shook, Robin P; VanGunday, Tiffany B; Galbreath, M Melyn; Reelick, Miriam F; Levine, Benjamin D

    2009-05-01

    that the menstrual cycle affects sympathetic neural responses but not sympathetic baroreflex sensitivity during orthostasis, though upright vasomotor sympathetic activity is not clearly different between men and women. Not only sympathetic but also cardiovagal baroreflex sensitivity is similar between sexes and menstrual phases during a hypotensive stimulus. However, cardiovagal baroreflex-mediated bradycardia during a hypertensive stimulus is different between sexes but not affected by the menstrual cycle. Thus, other factors rather than sympathetic baroreflex control mechanisms contribute to sex differences in orthostatic tolerance in young humans.

  17. Acute D3 Antagonist GSK598809 Selectively Enhances Neural Response During Monetary Reward Anticipation in Drug and Alcohol Dependence.

    PubMed

    Murphy, Anna; Nestor, Liam J; McGonigle, John; Paterson, Louise; Boyapati, Venkataramana; Ersche, Karen D; Flechais, Remy; Kuchibatla, Shankar; Metastasio, Antonio; Orban, Csaba; Passetti, Filippo; Reed, Laurence; Smith, Dana; Suckling, John; Taylor, Eleanor; Robbins, Trevor W; Lingford-Hughes, Anne; Nutt, David J; Deakin, John Fw; Elliott, Rebecca

    2017-04-01

    Evidence suggests that disturbances in neurobiological mechanisms of reward and inhibitory control maintain addiction and provoke relapse during abstinence. Abnormalities within the dopamine system may contribute to these disturbances and pharmacologically targeting the D3 dopamine receptor (DRD3) is therefore of significant clinical interest. We used functional magnetic resonance imaging to investigate the acute effects of the DRD3 antagonist GSK598809 on anticipatory reward processing, using the monetary incentive delay task (MIDT), and response inhibition using the Go/No-Go task (GNGT). A double-blind, placebo-controlled, crossover design approach was used in abstinent alcohol dependent, abstinent poly-drug dependent and healthy control volunteers. For the MIDT, there was evidence of blunted ventral striatal response to reward in the poly-drug-dependent group under placebo. GSK598809 normalized ventral striatal reward response and enhanced response in the DRD3-rich regions of the ventral pallidum and substantia nigra. Exploratory investigations suggested that the effects of GSK598809 were mainly driven by those with primary dependence on alcohol but not on opiates. Taken together, these findings suggest that GSK598809 may remediate reward deficits in substance dependence. For the GNGT, enhanced response in the inferior frontal cortex of the poly-drug group was found. However, there were no effects of GSK598809 on the neural network underlying response inhibition nor were there any behavioral drug effects on response inhibition. GSK598809 modulated the neural network underlying reward anticipation but not response inhibition, suggesting that DRD3 antagonists may restore reward deficits in addiction.

  18. A Decline in Response Variability Improves Neural Signal Detection during Auditory Task Performance.

    PubMed

    von Trapp, Gardiner; Buran, Bradley N; Sen, Kamal; Semple, Malcolm N; Sanes, Dan H

    2016-10-26

    The detection of a sensory stimulus arises from a significant change in neural activity, but a sensory neuron's response is rarely identical to successive presentations of the same stimulus. Large trial-to-trial variability would limit the central nervous system's ability to reliably detect a stimulus, presumably affecting perceptual performance. However, if response variability were to decrease while firing rate remained constant, then neural sensitivity could improve. Here, we asked whether engagement in an auditory detection task can modulate response variability, thereby increasing neural sensitivity. We recorded telemetrically from the core auditory cortex of gerbils, both while they engaged in an amplitude-modulation detection task and while they sat quietly listening to the identical stimuli. Using a signal detection theory framework, we found that neural sensitivity was improved during task performance, and this improvement was closely associated with a decrease in response variability. Moreover, units with the greatest change in response variability had absolute neural thresholds most closely aligned with simultaneously measured perceptual thresholds. Our findings suggest that the limitations imposed by response variability diminish during task performance, thereby improving the sensitivity of neural encoding and potentially leading to better perceptual sensitivity.

  19. Neural and Response Correlations to Complex Natural Sounds in the Auditory Midbrain

    PubMed Central

    Lyzwa, Dominika; Wörgötter, Florentin

    2016-01-01

    How natural communication sounds are spatially represented across the inferior colliculus, the main center of convergence for auditory information in the midbrain, is not known. The neural representation of the acoustic stimuli results from the interplay of locally differing input and the organization of spectral and temporal neural preferences that change gradually across the nucleus. This raises the question of how similar the neural representation of the communication sounds is across these gradients of neural preferences, and whether it also changes gradually. Analyzed neural recordings were multi-unit cluster spike trains from guinea pigs presented with a spectrotemporally rich set of eleven species-specific communication sounds. Using cross-correlation, we analyzed the response similarity of spiking activity across a broad frequency range for neurons of similar and different frequency tuning. Furthermore, we separated the contribution of the stimulus to the correlations to investigate whether similarity is only attributable to the stimulus, or, whether interactions exist between the multi-unit clusters that lead to neural correlations and whether these follow the same representation as the response correlations. We found that similarity of responses is dependent on the neurons' spatial distance for similarly and differently frequency-tuned neurons, and that similarity decreases gradually with spatial distance. Significant neural correlations exist, and contribute to the total response similarity. Our findings suggest that for multi-unit clusters in the mammalian inferior colliculus, the gradual response similarity with spatial distance to natural complex sounds is shaped by neural interactions and the gradual organization of neural preferences. PMID:27891078

  20. Neural and Response Correlations to Complex Natural Sounds in the Auditory Midbrain.

    PubMed

    Lyzwa, Dominika; Wörgötter, Florentin

    2016-01-01

    How natural communication sounds are spatially represented across the inferior colliculus, the main center of convergence for auditory information in the midbrain, is not known. The neural representation of the acoustic stimuli results from the interplay of locally differing input and the organization of spectral and temporal neural preferences that change gradually across the nucleus. This raises the question of how similar the neural representation of the communication sounds is across these gradients of neural preferences, and whether it also changes gradually. Analyzed neural recordings were multi-unit cluster spike trains from guinea pigs presented with a spectrotemporally rich set of eleven species-specific communication sounds. Using cross-correlation, we analyzed the response similarity of spiking activity across a broad frequency range for neurons of similar and different frequency tuning. Furthermore, we separated the contribution of the stimulus to the correlations to investigate whether similarity is only attributable to the stimulus, or, whether interactions exist between the multi-unit clusters that lead to neural correlations and whether these follow the same representation as the response correlations. We found that similarity of responses is dependent on the neurons' spatial distance for similarly and differently frequency-tuned neurons, and that similarity decreases gradually with spatial distance. Significant neural correlations exist, and contribute to the total response similarity. Our findings suggest that for multi-unit clusters in the mammalian inferior colliculus, the gradual response similarity with spatial distance to natural complex sounds is shaped by neural interactions and the gradual organization of neural preferences.

  1. Functional MRI and neural responses in a rat model of Alzheimer’s disease

    PubMed Central

    Sanganahalli, Basavaraju G.; Herman, Peter; Behar, Kevin L.; Blumenfeld, Hal; Rothman, Douglas L.; Hyder, Fahmeed

    2013-01-01

    Based on the hypothesis that brain plaques and tangles can affect cortical functions in Alzheimer's disease (AD) and thus modify functional activity, we investigated functional responses in an AD rat model (called the Samaritan Alzheimer’s rat achieved by ventricular infusion of amyloid peptide) and age-matched healthy control. High-field functional magnetic resonance imaging (fMRI) and extracellular neural activity measurements were applied to characterize sensory-evoked responses. Electrical stimulation of the forepaw led to BOLD and neural responses in the contralateral somatosensory cortex and thalamus. In AD brain we noted much smaller BOLD activation patterns in the somatosensory cortex (i.e., about 50% less activated voxels compared to normal brain). While magnitudes of BOLD and neural responses in the cerebral cortex were markedly attenuated in AD rats compared to normal rats (by about 50%), the dynamic coupling between the BOLD and neural responses in the cerebral cortex, as assessed by transfer function analysis, remained unaltered between the groups. However thalamic BOLD and neural responses were unaltered in AD brain compared to controls. Thus cortical responses in the AD model were indeed diminished compared to controls, but the thalamic responses in the AD and control rats were quite similar. Therefore these results suggest that Alzheimer’s disease may affect cortical function more than subcortical function, which may have implications for interpreting altered human brain functional responses in fMRI studies of Alzheimer’s disease. PMID:23648961

  2. Dynamic Encoding of Acoustic Features in Neural Responses to Continuous Speech.

    PubMed

    Khalighinejad, Bahar; Cruzatto da Silva, Guilherme; Mesgarani, Nima

    2017-02-22

    Humans are unique in their ability to communicate using spoken language. However, it remains unclear how the speech signal is transformed and represented in the brain at different stages of the auditory pathway. In this study, we characterized electroencephalography responses to continuous speech by obtaining the time-locked responses to phoneme instances (phoneme-related potential). We showed that responses to different phoneme categories are organized by phonetic features. We found that each instance of a phoneme in continuous speech produces multiple distinguishable neural responses occurring as early as 50 ms and as late as 400 ms after the phoneme onset. Comparing the patterns of phoneme similarity in the neural responses and the acoustic signals confirms a repetitive appearance of acoustic distinctions of phonemes in the neural data. Analysis of the phonetic and speaker information in neural activations revealed that different time intervals jointly encode the acoustic similarity of both phonetic and speaker categories. These findings provide evidence for a dynamic neural transformation of low-level speech features as they propagate along the auditory pathway, and form an empirical framework to study the representational changes in learning, attention, and speech disorders.SIGNIFICANCE STATEMENT We characterized the properties of evoked neural responses to phoneme instances in continuous speech. We show that each instance of a phoneme in continuous speech produces several observable neural responses at different times occurring as early as 50 ms and as late as 400 ms after the phoneme onset. Each temporal event explicitly encodes the acoustic similarity of phonemes, and linguistic and nonlinguistic information are best represented at different time intervals. Finally, we show a joint encoding of phonetic and speaker information, where the neural representation of speakers is dependent on phoneme category. These findings provide compelling new evidence for

  3. Dynamic Encoding of Acoustic Features in Neural Responses to Continuous Speech

    PubMed Central

    Khalighinejad, Bahar; Cruzatto da Silva, Guilherme

    2017-01-01

    Humans are unique in their ability to communicate using spoken language. However, it remains unclear how the speech signal is transformed and represented in the brain at different stages of the auditory pathway. In this study, we characterized electroencephalography responses to continuous speech by obtaining the time-locked responses to phoneme instances (phoneme-related potential). We showed that responses to different phoneme categories are organized by phonetic features. We found that each instance of a phoneme in continuous speech produces multiple distinguishable neural responses occurring as early as 50 ms and as late as 400 ms after the phoneme onset. Comparing the patterns of phoneme similarity in the neural responses and the acoustic signals confirms a repetitive appearance of acoustic distinctions of phonemes in the neural data. Analysis of the phonetic and speaker information in neural activations revealed that different time intervals jointly encode the acoustic similarity of both phonetic and speaker categories. These findings provide evidence for a dynamic neural transformation of low-level speech features as they propagate along the auditory pathway, and form an empirical framework to study the representational changes in learning, attention, and speech disorders. SIGNIFICANCE STATEMENT We characterized the properties of evoked neural responses to phoneme instances in continuous speech. We show that each instance of a phoneme in continuous speech produces several observable neural responses at different times occurring as early as 50 ms and as late as 400 ms after the phoneme onset. Each temporal event explicitly encodes the acoustic similarity of phonemes, and linguistic and nonlinguistic information are best represented at different time intervals. Finally, we show a joint encoding of phonetic and speaker information, where the neural representation of speakers is dependent on phoneme category. These findings provide compelling new evidence for

  4. Method for Constructing Composite Response Surfaces by Combining Neural Networks with other Interpolation or Estimation Techniques

    NASA Technical Reports Server (NTRS)

    Rai, Man Mohan (Inventor); Madavan, Nateri K. (Inventor)

    2003-01-01

    A method and system for design optimization that incorporates the advantages of both traditional response surface methodology (RSM) and neural networks is disclosed. The present invention employs a unique strategy called parameter-based partitioning of the given design space. In the design procedure, a sequence of composite response surfaces based on both neural networks and polynomial fits is used to traverse the design space to identify an optimal solution. The composite response surface has both the power of neural networks and the economy of low-order polynomials (in terms of the number of simulations needed and the network training requirements). The present invention handles design problems with many more parameters than would be possible using neural networks alone and permits a designer to rapidly perform a variety of trade-off studies before arriving at the final design.

  5. Diminished neural responses predict enhanced intrinsic motivation and sensitivity to external incentive.

    PubMed

    Marsden, Karen E; Ma, Wei Ji; Deci, Edward L; Ryan, Richard M; Chiu, Pearl H

    2015-06-01

    The duration and quality of human performance depend on both intrinsic motivation and external incentives. However, little is known about the neuroscientific basis of this interplay between internal and external motivators. Here, we used functional magnetic resonance imaging to examine the neural substrates of intrinsic motivation, operationalized as the free-choice time spent on a task when this was not required, and tested the neural and behavioral effects of external reward on intrinsic motivation. We found that increased duration of free-choice time was predicted by generally diminished neural responses in regions associated with cognitive and affective regulation. By comparison, the possibility of additional reward improved task accuracy, and specifically increased neural and behavioral responses following errors. Those individuals with the smallest neural responses associated with intrinsic motivation exhibited the greatest error-related neural enhancement under the external contingency of possible reward. Together, these data suggest that human performance is guided by a "tonic" and "phasic" relationship between the neural substrates of intrinsic motivation (tonic) and the impact of external incentives (phasic).

  6. Abnormalities of the scotopic threshold response correlated with gene mutation in X-linked retinoschisis and congenital stationary night blindness.

    PubMed

    Bradshaw, Keith; Newman, Douglas; Allen, Louise; Moore, Anthony

    2003-09-01

    STRs and dark-adapted ERGs were recorded in nine normal subjects, nine patients with XLRS, 11 patients with CSNB1 and one patient with CSNB2. In XLRS STR amplitude was significantly lower than normal at every intensity, but the response could be recorded in every patient and the maximum amplitude response was outside the 95% confidence limits in only four of the nine patients. STRs were significantly poorer in patients with CSNB and a responses was not measurable at any intensity in nine of the 11 patients with CSNB1. In both CSNB and XLRS the STR could only be recorded at higher stimulus intensities, suggesting reduced sensitivity of the STR. In XLRS onset and peak latencies were also significantly prolonged and the slope of the intensity-response functions for amplitude and onset latency differed significantly from normal. Maximum STR amplitude did not correlate with the maximum dark-adapted ERG response. The finding of abnormal STRs and dark adapted ERGs in all three dystrophies indicates that the different causative genes must have similar effects on the rod On-bipolar cell pathway. But there were also differences between the three clinical groups, particularly in the greater severity of the abnormality in CSNB1, which suggests that there may be multiple sites of abnormality.

  7. Internal Representation of Task Rules by Recurrent Dynamics: The Importance of the Diversity of Neural Responses

    PubMed Central

    Rigotti, Mattia; Rubin, Daniel Ben Dayan; Wang, Xiao-Jing; Fusi, Stefano

    2010-01-01

    Neural activity of behaving animals, especially in the prefrontal cortex, is highly heterogeneous, with selective responses to diverse aspects of the executed task. We propose a general model of recurrent neural networks that perform complex rule-based tasks, and we show that the diversity of neuronal responses plays a fundamental role when the behavioral responses are context-dependent. Specifically, we found that when the inner mental states encoding the task rules are represented by stable patterns of neural activity (attractors of the neural dynamics), the neurons must be selective for combinations of sensory stimuli and inner mental states. Such mixed selectivity is easily obtained by neurons that connect with random synaptic strengths both to the recurrent network and to neurons encoding sensory inputs. The number of randomly connected neurons needed to solve a task is on average only three times as large as the number of neurons needed in a network designed ad hoc. Moreover, the number of needed neurons grows only linearly with the number of task-relevant events and mental states, provided that each neuron responds to a large proportion of events (dense/distributed coding). A biologically realistic implementation of the model captures several aspects of the activity recorded from monkeys performing context-dependent tasks. Our findings explain the importance of the diversity of neural responses and provide us with simple and general principles for designing attractor neural networks that perform complex computation. PMID:21048899

  8. Subanesthetic Ketamine Treatment Promotes Abnormal Interactions between Neural Subsystems and Alters the Properties of Functional Brain Networks

    PubMed Central

    Dawson, Neil; McDonald, Martin; Higham, Desmond J; Morris, Brian J; Pratt, Judith A

    2014-01-01

    Acute treatment with subanesthetic ketamine, a non-competitive N-methyl-D-aspartic acid (NMDA) receptor antagonist, is widely utilized as a translational model for schizophrenia. However, how acute NMDA receptor blockade impacts on brain functioning at a systems level, to elicit translationally relevant symptomatology and behavioral deficits, has not yet been determined. Here, for the first time, we apply established and recently validated topological measures from network science to brain imaging data gained from ketamine-treated mice to elucidate how acute NMDA receptor blockade impacts on the properties of functional brain networks. We show that the effects of acute ketamine treatment on the global properties of these networks are divergent from those widely reported in schizophrenia. Where acute NMDA receptor blockade promotes hyperconnectivity in functional brain networks, pronounced dysconnectivity is found in schizophrenia. We also show that acute ketamine treatment increases the connectivity and importance of prefrontal and thalamic brain regions in brain networks, a finding also divergent to alterations seen in schizophrenia. In addition, we characterize how ketamine impacts on bipartite functional interactions between neural subsystems. A key feature includes the enhancement of prefrontal cortex (PFC)-neuromodulatory subsystem connectivity in ketamine-treated animals, a finding consistent with the known effects of ketamine on PFC neurotransmitter levels. Overall, our data suggest that, at a systems level, acute ketamine-induced alterations in brain network connectivity do not parallel those seen in chronic schizophrenia. Hence, the mechanisms through which acute ketamine treatment induces translationally relevant symptomatology may differ from those in chronic schizophrenia. Future effort should therefore be dedicated to resolve the conflicting observations between this putative translational model and schizophrenia. PMID:24492765

  9. Retinal Metric: A Stimulus Distance Measure Derived from Population Neural Responses

    NASA Astrophysics Data System (ADS)

    Tkačik, Gašper; Granot-Atedgi, Einat; Segev, Ronen; Schneidman, Elad

    2013-02-01

    The ability of an organism to distinguish between various stimuli is limited by the structure and noise in the population code of its sensory neurons. Here we infer a distance measure on the stimulus space directly from the recorded activity of 100 neurons in the salamander retina. In contrast to previously used measures of stimulus similarity, this “neural metric” tells us how distinguishable a pair of stimulus clips is to the retina, based on the similarity between the induced distributions of population responses. We show that the retinal distance strongly deviates from Euclidean, or any static metric, yet has a simple structure: we identify the stimulus features that the neural population is jointly sensitive to, and show the support-vector-machine-like kernel function relating the stimulus and neural response spaces. We show that the non-Euclidean nature of the retinal distance has important consequences for neural decoding.

  10. Design and implementation of in vivo imaging of neural injury responses in the adult Drosophila wing.

    PubMed

    Fang, Yanshan; Soares, Lorena; Bonini, Nancy M

    2013-04-01

    Live-imaging technology has markedly advanced in the field of neural injury and axon degeneration; however, studies are still predominantly performed in in vitro settings such as cultured neuronal cells or in model organisms such as Caenorhabditis elegans in which axons lack glial wrappings. We recently developed a new in vivo model for adult-stage neural injury in Drosophila melanogaster, using the highly accessible wing of the animal. Because the Drosophila wing is translucent and dispensable for survival, it allows clear and direct visualization of injury-induced progressive responses of axons and glia highlighted by fluorescent protein (FP) markers in live animals over time. Moreover, unlike previous Drosophila models of neural injury, this procedure does not require dissection of the CNS. Thus, the key preparation steps for in vivo imaging of the neural injury response described in this protocol can be completed within 30 min.

  11. Mechanism of the differentiation of neural responses to excitatory input signals

    NASA Astrophysics Data System (ADS)

    Zakharov, D. G.; Kuznetsov, A. S.

    2012-08-01

    A dynamical mechanism of the generation of qualitatively different neural responses to typical excitatory stimuli such as an applied current or AMPA and NMDA synaptic currents has been presented. The mechanism is based on a nonlinearity simulating the calcium-dependent potassium current. It has been shown with the FitzHugh-Nagumo equation that, in the presence of such a nonlinearity, only the NMDA synaptic current can strongly increase the frequency of self-sustained oscillations, whereas other stimuli suppress neural activity.

  12. Congenital Abnormalities

    MedlinePlus

    ... Listen Español Text Size Email Print Share Congenital Abnormalities Page Content Article Body About 3% to 4% ... of congenital abnormalities earlier. 5 Categories of Congenital Abnormalities Chromosome Abnormalities Chromosomes are structures that carry genetic ...

  13. Adult attachment style modulates neural responses in a mentalizing task.

    PubMed

    Schneider-Hassloff, H; Straube, B; Nuscheler, B; Wemken, G; Kircher, T

    2015-09-10

    Adult attachment style (AAS) is a personality trait that affects social cognition. Behavioral data suggest that AAS influences mentalizing proficiency, i.e. the ability to predict and explain people's behavior with reference to mental states, but the neural correlates are unknown. We here tested how the AAS dimensions "avoidance" (AV) and "anxiety" (ANX) modulate neural correlates of mentalizing. We measured brain activation using functional magnetic resonance imaging (fMRI) in 164 healthy subjects during an interactive mentalizing paradigm (Prisoner's Dilemma Game). AAS was assessed with the Relationship Scales Questionnaire, including the subscales AV and ANX. Our task elicited a strong activation of the mentalizing network, including bilateral precuneus, (anterior, middle, and posterior) cingulate cortices, temporal poles, inferior frontal gyri (IFG), temporoparietal junctions, superior medial frontal gyri as well as right medial orbital frontal gyrus, superior temporal gyrus, middle frontal gyrus (MFG), and amygdala. We found that AV is positively and ANX negatively correlated with task-associated neural activity in the right amygdala, MFG, midcingulate cortex, and superior parietal lobule, and in bilateral IFG. These data suggest that avoidantly attached adults activate brain areas implicated in emotion regulation and cognitive control to a larger extent than anxiously attached individuals during mentalizing.

  14. ABNORMAL FERTILIZATION IS RESPONSIBLE FOR REDUCED FECUNDITY FOLLOWING THIRAM-INDUCED OVULATORY DELAY IN THE RAT

    EPA Science Inventory

    Brief exposure to some pesticides, applied during a sensitive window for the neural regulation of ovulation, will block the preovulatory surge of LH, and thus delay ovulation. Previously, we have shown that a single i.p. injection of 50 mg/kg of thiram, a dithiocarbamate fungici...

  15. Abnormal osteogenic and chondrogenic differentiation of human mesenchymal stem cells from patients with adolescent idiopathic scoliosis in response to melatonin

    PubMed Central

    Chen, Chong; Xu, Caixia; Zhou, Taifeng; Gao, Bo; Zhou, Hang; Chen, Changhua; Zhang, Changli; Huang, Dongsheng; Su, Peiqiang

    2016-01-01

    Abnormalities of membranous and endochondral ossification in patients with adolescent idiopathic scoliosis (AIS) remain incompletely understood. To investigate abnormalities in the melatonin signaling pathway and cellular response to melatonin in AIS, a case-control study of osteogenic and chondrogenic differentiation was performed using human mesenchymal stem cells (hMSCs). AIS was diagnosed by physical and radiographic examination. hMSCs were isolated from the bone marrow of patients with AIS and control subjects (n=12 each), and purified by density gradient centrifugation. The expression levels of melatonin receptors (MTs) 1 and 2 were detected by western blotting. Osteogenic and chondrogenic differentiation was induced by culturing hMSCs in osteogenic and chondrogenic media containing vehicle or 50 nM melatonin. Alkaline phosphatase (ALP) activity assays, quantitative glycosaminoglycan (GAG) analysis, and reverse transcription-quantitative polymerase chain reaction analysis were performed. Compared with controls, MT2 demonstrated low expression in the AIS group. Melatonin increased ALP activity, GAG synthesis and upregulated the expression of genes involved in osteogenic and chondrogenic differentiation including, ALP, osteopontin, osteocalcin, runt-related transcription factor 2, collagen type II, collagen type X, aggrecan and sex-determining region Y-box 9 in the normal control hMSCs, but did not affect the AIS groups. Thus, AIS hMSCs exhibit abnormal cellular responses to melatonin during osteogenic and chondrogenic differentiation, which may be associated with abnormal membranous and endochondral ossification, and skeletal growth. These results indicate a potential modulating role of melatonin via the MT2 receptor on abnormal osteogenic and chondrogenic differentiaation in patients with AIS. PMID:27314307

  16. Neural and Behavioral Responses during Self-Evaluative Processes Differ in Youth with and without Autism

    ERIC Educational Resources Information Center

    Pfeifer, Jennifer H.; Merchant, Junaid S.; Colich, Natalie L.; Hernandez, Leanna M.; Rudie, Jeff D.; Dapretto, Mirella

    2013-01-01

    This fMRI study investigated neural responses while making appraisals of self and other, across the social and academic domains, in children and adolescents with and without autism spectrum disorders (ASD). Compared to neurotypical youth, those with ASD exhibited hypoactivation of ventromedial prefrontal cortex during self-appraisals. Responses in…

  17. Neural Mechanisms of Improvements in Social Motivation after Pivotal Response Treatment: Two Case Studies

    ERIC Educational Resources Information Center

    Voos, Avery C.; Pelphrey, Kevin A.; Tirrell, Jonathan; Bolling, Danielle Z.; Vander Wyk, Brent; Kaiser, Martha D.; McPartland, James C.; Volkmar, Fred R.; Ventola, Pamela

    2013-01-01

    Pivotal response treatment (PRT) is an empirically validated behavioral treatment that has widespread positive effects on communication, behavior, and social skills in young children with autism spectrum disorder (ASD). For the first time, functional magnetic resonance imaging was used to identify the neural correlates of successful response to…

  18. ADULT NEURAL STEM CELLS: RESPONSE TO STROKE INJURY AND POTENTIAL FOR THERAPEUTIC APPLICATIONS

    PubMed Central

    Barkho, Basam Z.; Zhao, Xinyu

    2011-01-01

    The plasticity of neural stem/progenitor cells allows a variety of different responses to many environmental cues. In the past decade, significant research has gone into understanding the regulation of neural stem/progenitor cell properties, because of their promise for cell replacement therapies in adult neurological diseases. Both endogenous and grafted neural stem/progenitor cells are known to have the ability to migrate long distances to lesioned sites after brain injury and differentiate into new neurons. Several chemokines and growth factors, including stromal cell-derived factor-1 and vascular endothelial growth factor, have been shown to stimulate the proliferation, differentiation, and migration of neural stem/progenitor cells, and investigators have now begun to identify the critical downstream effectors and signaling mechanisms that regulate these processes. Both our own lab and others have shown that the extracellular matrix and matrix remodeling factors play a critical role in directing cell differentiation and migration of adult neural stem/progenitor cells within injured sites. Identification of these and other molecular pathways involved in stem cell homing into ischemic areas is vital for the development of new treatments. To ensure the best functional recovery, regenerative therapy may require the application of a combination approach that includes cell replacement, trophic support, and neural protection. Here we review the current state of our knowledge about endogenous adult and exogenous neural stem/progenitor cells as potential therapeutic agents for central nervous system injuries. PMID:21466483

  19. A de novo microdeletion in a patient with inner ear abnormalities suggests that the 10q26.13 region contains the responsible gene.

    PubMed

    Sangu, Noriko; Okamoto, Nobuhiko; Shimojima, Keiko; Ondo, Yumiko; Nishikawa, Masanori; Yamamoto, Toshiyuki

    2016-01-01

    Microdeletions in the 10q26.1 region are related to intellectual disability, growth delay, microcephaly, distinctive craniofacial features, cardiac defects, genital abnormalities and inner ear abnormalities. The genes responsible for inner ear abnormalities have been narrowed to fibroblast growth factor receptor 2 gene (FGFR2), H6 family homeobox 2 gene (HMX2) and H6 family homeobox 3 gene (HMX3). An additional patient with distinctive craniofacial features, congenital deafness and balance dysfunctions showed a de novo microdeletion of 10q26.11q26.13, indicating the existence of a gene responsible for inner ear abnormalities in this region.

  20. Neural responses to others' pain vary with psychopathic traits in healthy adult males.

    PubMed

    Seara-Cardoso, Ana; Viding, Essi; Lickley, Rachael A; Sebastian, Catherine L

    2015-09-01

    Disrupted empathic processing is a core feature of psychopathy. Neuroimaging data have suggested that individuals with high levels of psychopathic traits show atypical responses to others' pain in a network of brain regions typically recruited during empathic processing (anterior insula, inferior frontal gyrus, and mid- and anterior cingulate cortex). Here, we investigated whether neural responses to others' pain vary with psychopathic traits within the general population in a similar manner to that found in individuals at the extreme end of the continuum. As predicted, variation in psychopathic traits was associated with variation in neural responses to others' pain in the network of brain regions typically engaged during empathic processing. Consistent with previous research, our findings indicated the presence of suppressor effects in the association of levels of the affective-interpersonal and lifestyle-antisocial dimensions of psychopathy with neural responses to others' pain. That is, after controlling for the influence of the other dimension, higher affective-interpersonal psychopathic traits were associated with reduced neural responses to others' pain, whilst higher lifestyle-antisocial psychopathic traits were associated with increased neural responses to others' pain. Our findings provide further evidence that atypical function in this network might represent neural markers of disrupted emotional and empathic processing; that the two dimensions of psychopathy might tap into distinct underlying vulnerabilities; and, most importantly, that the relationships observed at the extreme end of the psychopathy spectrum apply to the nonclinical distribution of these traits, providing further evidence for continuities in the mechanisms underlying psychopathic traits across the general population.

  1. Post-weaning social isolation induces abnormal forms of aggression in conjunction with increased glucocorticoid and autonomic stress responses.

    PubMed

    Toth, Mate; Mikics, Eva; Tulogdi, Aron; Aliczki, Mano; Haller, Jozsef

    2011-06-01

    We showed earlier that social isolation from weaning (a paradigm frequently used to model social neglect in children) induces abnormal forms of attack in rats, and assumed that these are associated with hyperarousal. To investigate this hypothesis, we deprived rats of social contacts from weaning and studied their behavior, glucocorticoid and autonomic stress responses in the resident-intruder paradigm at the age of 82 days. Social isolation resulted in abnormal attack patterns characterized by attacks on vulnerable targets, deficient social communication and increased defensive behaviors (defensive upright, flight, freezing). During aggressive encounters, socially deprived rats rapidly switched from one behavior to another, i.e. showed an increased number of behavioral transitions as compared to controls. We tentatively term this behavioral feature "behavioral fragmentation" and considered it a form of behavioral arousal. Basal levels of plasma corticosterone regularly assessed by radioimmunoassay between 27 and 78 days of age were not affected. In contrast, aggression-induced glucocorticoid responses were approximately doubled by socially isolation. Diurnal oscillations in heart rate assessed by in vivo biotelemetry were not affected by social isolation. In contrast, the aggression-induced increase in heart rate was higher in socially isolated than in socially housed rats. Thus, post-weaning social isolation induced abnormal forms of aggression that developed on the background of increased behavioral, endocrine and autonomic arousal. We suggest that this paradigm may be used to model aggression-related psychopathologies associated with hyperarousal, particularly those that are triggered by adverse rearing conditions.

  2. Neural Response to Reward as a Predictor of Rise in Depressive Symptoms in Adolescence

    PubMed Central

    Morgan, Judith K.; Olino, Thomas M.; McMakin, Dana L.; Ryan, Neal D.; Forbes, Erika E.

    2012-01-01

    Adolescence is a developmental period characterized by significant increases in the onset of depression, but also by increases in depressive symptoms, even among psychiatrically healthy youth. Disrupted reward function has been postulated as a critical factor in the development of depression, but it is still unclear which adolescents are particularly at risk for rising depressive symptoms. We provide a conceptual stance on gender, pubertal development, and reward type as potential moderators of the association between neural response to reward and rises in depressive symptoms. In addition, we describe preliminary findings that support claims of this conceptual stance. We propose that (1) status-related rewards may be particularly salient for eliciting neural response relevant to depressive symptoms in boys, whereas social rewards may be more salient for eliciting neural response relevant to depressive symptoms in girls and (2) the pattern of reduced striatal response and enhanced medial prefrontal response to reward may be particularly predictive of depressive symptoms in pubertal adolescents. We found that greater vmPFC activation when winning rewards predicted greater increases in depressive symptoms over two years, for boys only, and less striatal activation when anticipating rewards predicted greater increases in depressive symptoms over two years, for adolescents in mid to late pubertal stages but not those in pre to early puberty. We also propose directions for future studies, including the investigation of social vs. monetary reward directly and the longitudinal assessment of parallel changes in pubertal development, neural response to reward, and depressive symptoms. PMID:22521464

  3. Neural response to eye contact and paroxetine treatment in generalized social anxiety disorder.

    PubMed

    Schneier, Franklin R; Pomplun, Marc; Sy, Melissa; Hirsch, Joy

    2011-12-30

    Generalized social anxiety disorder (GSAD) is characterized by excessive fears of scrutiny and negative evaluation, but neural circuitry related to scrutiny in GSAD has been little studied. In this study, 16 unmedicated adults with GSAD and 16 matched healthy comparison (HC) participants underwent functional magnetic resonance imaging to assess neural response to viewed images of faces simulating movement into eye contact versus away from eye contact. GSAD patients were then treated for 8 weeks with paroxetine, and 15 patients were re-imaged. At baseline, GSAD patients had elevated neural response to eye contact in parahippocampal cortex, inferior parietal lobule, supramarginal gyrus, posterior cingulate and middle occipital cortex. During paroxetine treatment, symptomatic improvement was associated with decreased neural response to eye contact in regions including inferior and middle frontal gyri, anterior cingulate, posterior cingulate, precuneus and inferior parietal lobule. Both the magnitude of GSAD symptom reduction with paroxetine treatment and the baseline comparison of GSAD vs. HCs were associated with neural processing of eye contact in distributed networks that included regions involved in self-referential processing. These findings demonstrate that eye contact in GSAD engages neurocircuitry consistent with the heightened self-conscious emotional states known to characterize GSAD patients during scrutiny.

  4. The neural antecedents to voluntary action: Response to commentaries

    PubMed Central

    Nachev, Parashkev; Hacker, Peter

    2015-01-01

    Cognitive neuroscience must attend to the conceptual coherence of its hypotheses as well as to their empirical support. Examining the most influential studies of the neural antecedents to voluntary action, our Discussion Paper sought to identify the real-world consequences of neglecting the former in what we argued has been too narrow a pursuit of the latter. Though conceptual in form, our analysis is sharply empirical in its conclusions, revealing what have long been thought to be momentous experimental observations—such as the readiness potential—as the outcome of previously unidentified confounds that rob them of significance. Conversely, we suggested that experimental studies of two-way control, amongst other defining features of the voluntary, have been given less emphasis than the subject demands. Here, we ramify our analysis down the paths identified by others in the commentaries we received. PMID:26001157

  5. Dissociable Neural Response Signatures for Slow Amplitude and Frequency Modulation in Human Auditory Cortex

    PubMed Central

    Henry, Molly J.; Obleser, Jonas

    2013-01-01

    Natural auditory stimuli are characterized by slow fluctuations in amplitude and frequency. However, the degree to which the neural responses to slow amplitude modulation (AM) and frequency modulation (FM) are capable of conveying independent time-varying information, particularly with respect to speech communication, is unclear. In the current electroencephalography (EEG) study, participants listened to amplitude- and frequency-modulated narrow-band noises with a 3-Hz modulation rate, and the resulting neural responses were compared. Spectral analyses revealed similar spectral amplitude peaks for AM and FM at the stimulation frequency (3 Hz), but amplitude at the second harmonic frequency (6 Hz) was much higher for FM than for AM. Moreover, the phase delay of neural responses with respect to the full-band stimulus envelope was shorter for FM than for AM. Finally, the critical analysis involved classification of single trials as being in response to either AM or FM based on either phase or amplitude information. Time-varying phase, but not amplitude, was sufficient to accurately classify AM and FM stimuli based on single-trial neural responses. Taken together, the current results support the dissociable nature of cortical signatures of slow AM and FM. These cortical signatures potentially provide an efficient means to dissect simultaneously communicated slow temporal and spectral information in acoustic communication signals. PMID:24205309

  6. Mathematical impairment associated with high-contrast abnormalities in change detection and magnocellular visual evoked response.

    PubMed

    Jastrzebski, Nicola R; Crewther, Sheila G; Crewther, David P

    2015-10-01

    The cause of developmental dyscalculia, a specific deficit in acquisition of arithmetic skills, particularly of enumeration, has never been investigated with respect to the patency of the visual magnocellular system. Here, the question of dysfunction of the afferent magnocellular cortical input and its dorsal stream projections was tested directly using nonlinear analysis of the visual evoked potential (VEP) and through the psychophysical ability to rapidly detect visual change. A group of young adults with self-reported deficiencies of arithmetical ability, showed marked impairment in magnitude estimation and enumeration performance-though not in lexical decision reaction times when compared with an arithmetically capable group controlled for age and handedness. Multifocal nonlinear VEPs were recorded at low (24 %) and high (96 %) contrast. First- and second-order VEP kernels were comparable between groups at low contrast, but not at high contrast. The mathematically impaired group showed an abnormal lack of contrast saturation in the shortest latency first-order peak (N60) and a delayed P100 positivity in the first slice of the second-order kernel. Both features have previously been argued to be physiological markers of magnocellular function. Mathematically impaired participants also performed worse on a gap paradigm change detection for digit task showing increased reaction times for high-contrast stimuli but not for low-contrast stimuli compared with controls. The VEP results give direct evidence of abnormality in the occipital processing of magnocellular information in those with mathematical impairment. The anomalous high visual contrast physiological and psychophysical performance suggests an abnormality in the inhibitory processes that normally result in saturation of contrast gain in the magnocellular system.

  7. Method for Constructing Composite Response Surfaces by Combining Neural Networks with Polynominal Interpolation or Estimation Techniques

    NASA Technical Reports Server (NTRS)

    Rai, Man Mohan (Inventor); Madavan, Nateri K. (Inventor)

    2007-01-01

    A method and system for data modeling that incorporates the advantages of both traditional response surface methodology (RSM) and neural networks is disclosed. The invention partitions the parameters into a first set of s simple parameters, where observable data are expressible as low order polynomials, and c complex parameters that reflect more complicated variation of the observed data. Variation of the data with the simple parameters is modeled using polynomials; and variation of the data with the complex parameters at each vertex is analyzed using a neural network. Variations with the simple parameters and with the complex parameters are expressed using a first sequence of shape functions and a second sequence of neural network functions. The first and second sequences are multiplicatively combined to form a composite response surface, dependent upon the parameter values, that can be used to identify an accurate mode

  8. The Neural Basis of Cognitive Control: Response Selection and Inhibition

    ERIC Educational Resources Information Center

    Goghari, Vina M.; MacDonald, Angus W., III

    2009-01-01

    The functional neuroanatomy of tasks that recruit different forms of response selection and inhibition has to our knowledge, never been directly addressed in a single fMRI study using similar stimulus-response paradigms where differences between scanning time and sequence, stimuli, and experimenter instructions were minimized. Twelve right-handed…

  9. Parametric characterization of neural activity in the locus coeruleus in response to vagus nerve stimulation.

    PubMed

    Hulsey, Daniel R; Riley, Jonathan R; Loerwald, Kristofer W; Rennaker, Robert L; Kilgard, Michael P; Hays, Seth A

    2017-03-01

    Vagus nerve stimulation (VNS) has emerged as a therapy to treat a wide range of neurological disorders, including epilepsy, depression, stroke, and tinnitus. Activation of neurons in the locus coeruleus (LC) is believed to mediate many of the effects of VNS in the central nervous system. Despite the importance of the LC, there is a dearth of direct evidence characterizing neural activity in response to VNS. A detailed understanding of the brain activity evoked by VNS across a range of stimulation parameters may guide selection of stimulation regimens for therapeutic use. In this study, we recorded neural activity in the LC and the mesencephalic trigeminal nucleus (Me5) in response to VNS over a broad range of current amplitudes, pulse frequencies, train durations, inter-train intervals, and pulse widths. Brief 0.5s trains of VNS drive rapid, phasic firing of LC neurons at 0.1mA. Higher current intensities and longer pulse widths drive greater increases in LC firing rate. Varying the pulse frequency substantially affects the timing, but not the total amount, of phasic LC activity. VNS drives pulse-locked neural activity in the Me5 at current levels above 1.2mA. These results provide insight into VNS-evoked phasic neural activity in multiple neural structures and may be useful in guiding the selection of VNS parameters to enhance clinical efficacy.

  10. Play It Again: Neural Responses to Reunion with Excluders Predicted by Attachment Patterns

    ERIC Educational Resources Information Center

    White, Lars O.; Wu, Jia; Borelli, Jessica L.; Mayes, Linda C.; Crowley, Michael J.

    2013-01-01

    Reunion behavior following stressful separations from caregivers is often considered the single most sensitive clue to infant attachment patterns. Extending these ideas to middle childhood/early adolescence, we examined participants' neural responses to reunion with peers who had previously excluded them. We recorded event-related potentials…

  11. Associations among Pubertal Development, Empathic Ability, and Neural Responses While Witnessing Peer Rejection in Adolescence

    ERIC Educational Resources Information Center

    Masten, Carrie L.; Eisenberger, Naomi I.; Pfeifer, Jennifer H.; Colich, Natalie L.; Dapretto, Mirella

    2013-01-01

    Links among concurrent and longitudinal changes in pubertal development and empathic ability from ages 10 to 13 and neural responses while witnessing peer rejection at age 13 were examined in 16 participants. More advanced pubertal development at age 13, and greater longitudinal increases in pubertal development, related to increased activity in…

  12. Blunted neural response to rewards as a vulnerability factor for depression: Results from a family study.

    PubMed

    Weinberg, Anna; Liu, Huiting; Hajcak, Greg; Shankman, Stewart A

    2015-11-01

    Depressive disorders are associated with significant economic and public health burdens as well as increased morbidity. Yet, perhaps due to the heterogeneous nature of the disease, prevention and intervention efforts are only moderately efficacious. A better understanding of core mechanisms of depressive disorders might aid in the development of more targeted intervention, and perhaps help identify individuals at risk. One mechanism that may be particularly important to depressive phenotypes is reward insensitivity. Examination of neurobiological correlates of reward-processing, which should relate more directly to the neuropathology of depression, may be helpful in identifying liability for the disorder. To that end, we used a family study design to examine whether a neural response to rewards is a familial risk factor for depression in a sample of probands with a wide range of internalizing psychopathology, as well as their biological siblings. Event-related potentials were recorded during a simple forced-choice gambling paradigm, in which participants could either win or lose small amounts of money. Lower levels of positive affect in probands predicted a reduced neural response to rewards in siblings, even over and above the sibling's own level of positive and negative affect. Additionally, the neural response to rewards was familial (i.e., correlated among siblings). Combined, these analyses suggest that a blunted neural response to rewards may be useful in identifying individuals vulnerable to depressive illnesses.

  13. The modified gait abnormality rating scale in patients with a conversion disorder: a reliability and responsiveness study.

    PubMed

    Vandenberg, Justin M; George, Deanna R; O'Leary, Andrea J; Olson, Lindsay C; Strassburg, Kaitlyn R; Hollman, John H

    2015-01-01

    Individuals with conversion disorder have neurologic symptoms that are not identified by an underlying organic cause. Often the symptoms manifest as gait disturbances. The modified gait abnormality rating scale (GARS-M) may be useful for quantifying gait abnormalities in these individuals. The purpose of this study was to examine the reliability, responsiveness and concurrent validity of GARS-M scores in individuals with conversion disorder. Data from 27 individuals who completed a rehabilitation program were included in this study. Pre- and post-intervention videos were obtained and walking speed was measured. Five examiners independently evaluated gait performance according to the GARS-M criteria. Inter- and intrarater reliability of GARS-M scores were estimated with intraclass correlation coefficients (ICCs). Responsiveness was estimated with the minimum detectable change (MDC). Pre- to post-treatment changes in GARS-M scores were analyzed with a dependent t-test. The correlation between GARS-M scores and walking speed was analyzed to assess concurrent validity. GARS-M scores were quantified with good-to-excellent inter- (ICC = 0.878) and intrarater reliability (ICC = 0.989). The MDC was 2 points. Mean GARS-M scores decreased from 7 ± 5 at baseline to 1 ± 2 at discharge (t26 = 7.411, p < 0.001) and 85% of patients improved beyond the MDC. Furthermore, GARS-M scores and walking speed measurements were moderately correlated (r = -0.582, p = 0.004), indicating that the GARS-M has acceptable concurrent validity. Our findings provide evidence that the GARS-M scores are reliable, valid and responsive for quantifying gait abnormalities in patients with conversion disorder. GARS-M scores provide objective measures upon which treatment effects can be assessed.

  14. Mechanisms determining cholinergic neural responses in airways of young and mature rabbits.

    PubMed

    Larsen, Gary L; Loader, Joan; Nguyen, Dee Dee; Fratelli, Cori; Dakhama, Azzeddine; Colasurdo, Giuseppe N

    2004-08-01

    Neural pathways help control airway caliber and responsiveness. Yet little is known of how neural control changes as a function of development. In rabbits, we found electrical field stimulation (EFS) of airway nerves led to more marked contractile responses in 2- vs. 13-week-old animals. This enhanced response to EFS may be due to prejunctional, junctional, and/or postjunctional neural mechanisms. We assessed these mechanisms in airways of 2- and 13-week-old rabbits. The contractile responses to methacholine did not differ in the groups, suggesting postjunctional neural events are not primarily responsible for differing responses to EFS. To address junctional events, acetylcholinesterase (AChE) was measured (spectrophotometry). AChE was elevated in 2-week-olds. However, this should lead to less and not greater responses. Prejunctionally, EFS-induced acetylcholine (ACh) release was assessed by HPLC. Airways of 2-week-old rabbits released significantly more ACh than airways from mature rabbits. Choline acetyltransferase, a marker of cholinergic nerves, was not different between groups, suggesting that more ACh release in young rabbits was not due to increased nerve density. ACh release in the presence of polyarginine increased significantly in both groups, supporting the presence of functional muscarinic autoreceptors (M2) at both ages. Because substance P (SP) increases release of ACh, SP was measured by ELISA. This neuropeptide was significantly elevated in airways of younger rabbits. Nerve growth factor (NGF) increased SP and was also significantly increased in airways from younger rabbits. This work suggests that increases in EFS-induced responsiveness in young rabbits are likely due to prejunctional events with enhanced release of ACh. Increases in NGF and SP early in life may contribute to this increased responsiveness.

  15. 'Abnormal' angle response curves of TW/Rs for near zero tilt and high tilt channeling implants

    SciTech Connect

    Guo Baonian; Gossmann, Hans-Joachim; Toh, Terry; Colombeau, Benjamin; Todorov, Stan; Sinclair, Frank; Shim, Kyu-Ha; Henry, Todd

    2012-11-06

    Angle control has been widely accepted as the key requirement for ion implantation in semiconductor device processing. From an ion implanter point of view, the incident ion direction should be measured and corrected by suitable techniques, such as XP-VPS for the VIISta implanter platform, to ensure precision ion placement in device structures. So called V-curves have been adopted to generate the wafer-based calibration using channeling effects as the Si lattice steer ions into a channeling direction. Thermal Wave (TW) or sheet resistance (Rs) can be used to determine the minimum of the angle response curve. Normally it is expected that the TW and Rs have their respective minima at identical angles. However, the TW and Rs response to the angle variations does depend on factors such as implant species, dose, and wafer temperature. Implant damage accumulation effects have to be considered for data interpretation especially for some 'abnormal' V-curve data. In this paper we will discuss some observed 'abnormal' angle responses, such as a) TW/Rs reverse trend for Arsenic beam, 2) 'W' shape of Rs Boron, and 3) apparent TW/Rs minimum difference for high tilt characterization, along with experimental data and TCAD simulations.

  16. ADOLECSENT MANIA, EEG ABNORMALITY AND RESPONSE TO ANTICONVULSANTS: A THREE - YEAR FOLLOW-UP STUDY

    PubMed Central

    Aich, Tapas K.; Sinha, Vinod Kumar; Nizami, Hauque S.

    2001-01-01

    We had reported earlier (1998) a high percentage of moderate to severe EEG abnormalities (43.75% of cases) amongst adolescent manic population. Sixteen adolescent manics, with a mean age of 14 9 years, diagnosed according to ICD-10 were taken up for the initial study. Present study is the three-year follow-up report of 67.75% (11 out of 16) of the original patient population. All these patients were subjected fc 21-channel EEG and anticonvulsant drugs were started to all. Follow-up data showed that 3 out of 6 patients, who discontinued medications, were relapsed during this 3 years period. But none of the 5 patients, who regularly took prescribed medicines, relapsed during the same period. Significance of these findings in relapse prevention and the role of anticonvulsants, particularly in relation to adolescent mania, have been emphasized. PMID:21407863

  17. Three-Dimensional Flexible Electronics Enabled by Shape Memory Polymer Substrates for Responsive Neural Interfaces

    PubMed Central

    Ware, Taylor; Simon, Dustin; Hearon, Keith; Liu, Clive; Shah, Sagar; Reeder, Jonathan; Khodaparast, Navid; Kilgard, Michael P.; Maitland, Duncan J.; Rennaker, Robert L.; Voit, Walter E.

    2014-01-01

    Planar electronics processing methods have enabled neural interfaces to become more precise and deliver more information. However, this processing paradigm is inherently 2D and rigid. The resulting mechanical and geometrical mismatch at the biotic–abiotic interface can elicit an immune response that prevents effective stimulation. In this work, a thiol–ene/acrylate shape memory polymer is utilized to create 3D softening substrates for stimulation electrodes. This substrate system is shown to soften in vivo from more than 600 to 6 MPa. A nerve cuff electrode that coils around the vagus nerve in a rat and that drives neural activity is demonstrated. PMID:25530708

  18. An Auditory Processing Abnormality Specific to Liability for Schizophrenia

    PubMed Central

    Force, Rachel B.; Venables, Noah C.; Sponheim, Scott R.

    2013-01-01

    Abnormal brain activity during the processing of simple sounds is evident in individuals with increased genetic liability for schizophrenia; however, the diagnostic specificity of these abnormalities has yet to be fully examined. Because recent evidence suggests that schizophrenia and bipolar disorder may share aspects of genetic etiology the present study was conducted to determine whether individuals with heightened genetic liability for each disorder manifested distinct neural abnormalities during auditory processing. Utilizing a dichotic listening paradigm, we assessed target tone discrimination and electrophysiological responses in schizophrenia patients, first-degree biological relatives of schizophrenia patients, bipolar disorder patients, first-degree biological relatives of bipolar patients and nonpsychiatric control participants. Schizophrenia patients and relatives of schizophrenia patients demonstrated reductions in an early neural response (i.e. N1) suggestive of deficient sensory registration of auditory stimuli. Bipolar patients and relatives of bipolar patients demonstrated no such abnormality. Both schizophrenia and bipolar patients failed to significantly augment N1 amplitude with attention. Schizophrenia patients also failed to show sensitivity of longer-latency neural processes (N2) to stimulus frequency suggesting a disorder specific deficit in stimulus classification. Only schizophrenia patients exhibited reduced target tone discrimination accuracy. Reduced N1 responses reflective of early auditory processing abnormalities are suggestive of a marker of genetic liability for schizophrenia and may serve as an endophenotype for the disorder. PMID:18571375

  19. Personality influences the neural responses to viewing facial expressions of emotion.

    PubMed

    Calder, Andrew J; Ewbank, Michael; Passamonti, Luca

    2011-06-12

    Cognitive research has long been aware of the relationship between individual differences in personality and performance on behavioural tasks. However, within the field of cognitive neuroscience, the way in which such differences manifest at a neural level has received relatively little attention. We review recent research addressing the relationship between personality traits and the neural response to viewing facial signals of emotion. In one section, we discuss work demonstrating the relationship between anxiety and the amygdala response to facial signals of threat. A second section considers research showing that individual differences in reward drive (behavioural activation system), a trait linked to aggression, influence the neural responsivity and connectivity between brain regions implicated in aggression when viewing facial signals of anger. Finally, we address recent criticisms of the correlational approach to fMRI analyses and conclude that when used appropriately, analyses examining the relationship between personality and brain activity provide a useful tool for understanding the neural basis of facial expression processing and emotion processing in general.

  20. Muscarinic receptor subtypes mediating the mucosal response to neural stimulation of guinea pig ileum

    SciTech Connect

    Carey, H.V.; Tien, X.Y.; Wallace, L.J.; Cooke, H.J.

    1987-09-01

    Muscarinic receptors involved in the secretory response evoked by electrical stimulation of submucosal neutrons were investigated in muscle-stripped flat sheets of guinea pig ileum set up in flux chambers. Neural stimulation produced a biphasic increase in short-circuit current due to active chloride secretion. Atropine and 4-diphenylacetoxy-N-methylpiperadine methiodide (4-DAMP) (10/sup -7/ M) were more potent inhibitors of the cholinergic phase of the response than was pirenzepine. Dose-dependent increases in base-line short-circuit current were evoked by carbachol and bethanechol; 4-hydroxy-2-butynyl trimethylammonium chloride (McN A343) produced a much smaller effect. Tetrodotoxin abolished the effects of McN A343 but did not alter the responses of carbachol and bethanechol. McN A343 significantly reduced the cholinergic phase of the neurally evoked response and caused a rightward shift of the carbachol dose-response curve. All muscarinic compounds inhibited (/sup 3/H)quinuclidinyl benzilate binding to membranes from muscosal scrapings, with a rank order of potency of 4-DAMP > pirenzepine > McN A343 > carbachol > bethanechol. These results suggest that acetylcholine released from submucosal neurons mediates chloride secretion by interacting with muscarinic cholinergic receptors that display a high binding affinity for 4-DAMP. Activation of neural muscarinic receptors makes a relatively small contribution to the overall secretory response.

  1. Approaching the Next Revolution? Evolutionary Integration of Neural and Immune Pathogen Sensing and Response

    PubMed Central

    Tracey, Kevin J.

    2015-01-01

    Mammalian immunity evolved by the process of natural selection that produced differential survival and reproduction advantages through combinations of hereditary traits underlying the response to pathogens. Primitive animals sense the presence of microbial pathogens through recognition of pathogen-derived molecules in their rudimentary immune and nervous systems. No molecular biological mechanism assigns primacy of pathogen sensing mechanisms to immune cells over neurons. Rather, in animals as diverse as Caenorhabditis elegans to mammals, neural reflexes are activated by the presence of pathogens and transduce neural mechanisms that control the development of immunity. A coming revolution in immunological thinking will require immunologists to incorporate neural circuits into understanding pathogen signal transduction, and the molecular mechanisms of learning, that culminate in immunity. PMID:25376836

  2. Monocyte Subpopulations from Pre-Eclamptic Patients Are Abnormally Skewed and Exhibit Exaggerated Responses to Toll-Like Receptor Ligands

    PubMed Central

    Al-ofi, Ebtisam

    2012-01-01

    The leading cause of pregnancy-associated mortality and morbidity is pre-eclampsia (PE). Although information regarding the etiology of this disease is scant, its pathophysiology is characterized by abnormal placentation, endothelial dysfunction as well as an exaggerated inflammatory response. Clinical evidence also indicates that the abundance of many immune cells at the feto-maternal interface and in the circulation of PE patients is abnormal, when compared with normal pregnant (NP) controls. In addition, the phenotype and function of some of these cells is altered. To further characterize the systemic effects of PE on circulating cells, we analyzed monocytic subpopulations in NP and PE patients by flow cytometry. We found that non-classical CD14lowCD16+ monocytes are significantly increased in women with PE and they display irregular expression of several chemokine receptors and antigen presentation molecules. The most striking phenotypic difference among the cell surface molecules was the marked upregulation of TLR4 expression, where both CD14highCD16+ and CD14lowCD16+ monocytes demonstrated higher levels than their NP counterparts. Stimulation of PE monocytes with TLR ligands resulted in profound secretion of various cytokines in comparison with NP controls. These data suggest that PE monocytes are hyper-responsive to TLR ligands and this may contribute to exacerbation of the disease. PMID:22848746

  3. Monocyte subpopulations from pre-eclamptic patients are abnormally skewed and exhibit exaggerated responses to Toll-like receptor ligands.

    PubMed

    Al-ofi, Ebtisam; Coffelt, Seth B; Anumba, Dilly O

    2012-01-01

    The leading cause of pregnancy-associated mortality and morbidity is pre-eclampsia (PE). Although information regarding the etiology of this disease is scant, its pathophysiology is characterized by abnormal placentation, endothelial dysfunction as well as an exaggerated inflammatory response. Clinical evidence also indicates that the abundance of many immune cells at the feto-maternal interface and in the circulation of PE patients is abnormal, when compared with normal pregnant (NP) controls. In addition, the phenotype and function of some of these cells is altered. To further characterize the systemic effects of PE on circulating cells, we analyzed monocytic subpopulations in NP and PE patients by flow cytometry. We found that non-classical CD14(low)CD16(+) monocytes are significantly increased in women with PE and they display irregular expression of several chemokine receptors and antigen presentation molecules. The most striking phenotypic difference among the cell surface molecules was the marked upregulation of TLR4 expression, where both CD14(high)CD16(+) and CD14(low)CD16(+) monocytes demonstrated higher levels than their NP counterparts. Stimulation of PE monocytes with TLR ligands resulted in profound secretion of various cytokines in comparison with NP controls. These data suggest that PE monocytes are hyper-responsive to TLR ligands and this may contribute to exacerbation of the disease.

  4. Neural network model of cortical EEG response to olfactory stimuli

    NASA Astrophysics Data System (ADS)

    Dunbar, George L.; Van Toller, Steve

    1995-04-01

    We describe three experiments attempting to model differences in cortical EEG following stimulation with different odors. The data used in these experiments was obtained in previous studies, described briefly here. Subjects sit in an environmentally stabilized low odor cubicle. Twenty-eight electrodes are placed on the scalp and connect the subject to a neurosciences brain imager, which digitizes cortical EEG response. In a given trial, a specific odor is introduced, and the response recorded. In the first experiment, alpha wave data from a subset of ten electrodes and a single subject was used. In the original experiment, the subject was presented with a number of odors and the resulting brain electrical activity was resolved into 16 time slices (5 preceding presentation, 4 during presentation and 7 following presentation). Only data from frames 6, 7 and 8 (during presentation) was used here. A model was constructed to discriminate morning from afternoon responses. The network used measurements from 10 electrodes as input, and backpropagation was used for training. During training, the network was presented with responses to just one odor. Generalization was demonstrated for five other odors. The weights in the network have been analyzed and indicate a role for a specific group of electrode sites in this discrimination. The second experiment involved constructing a network to discriminate cortical EEG responses to two odors. In the original experiment from which we drew our data, fourteen subjects were presented with each odor once. Data from only the frame at first presentation of the odor were used here. Data from three subjects (chosen pseudo-randomly) was selected for use in the generalization phase and dropped from the training set. Output targets were constructed that took account of subjective ratings of `pleasantness.' A feed-forward network with twenty-eight input units was trained using data from the eleven remaining subjects, using conjugate gradient

  5. Abnormal Striatal BOLD Responses to Reward Anticipation and Reward Delivery in ADHD

    PubMed Central

    Furukawa, Emi; Bado, Patricia; Tripp, Gail; Mattos, Paulo; Wickens, Jeff R.; Bramati, Ivanei E.; Alsop, Brent; Ferreira, Fernanda Meireles; Lima, Debora; Tovar-Moll, Fernanda; Sergeant, Joseph A.; Moll, Jorge

    2014-01-01

    Altered reward processing has been proposed to contribute to the symptoms of attention deficit hyperactivity disorder (ADHD). The neurobiological mechanism underlying this alteration remains unclear. We hypothesize that the transfer of dopamine release from reward to reward-predicting cues, as normally observed in animal studies, may be deficient in ADHD. Functional magnetic resonance imaging (fMRI) was used to investigate striatal responses to reward-predicting cues and reward delivery in a classical conditioning paradigm. Data from 14 high-functioning and stimulant-naïve young adults with elevated lifetime symptoms of ADHD (8 males, 6 females) and 15 well-matched controls (8 males, 7 females) were included in the analyses. During reward anticipation, increased blood-oxygen-level-dependent (BOLD) responses in the right ventral and left dorsal striatum were observed in controls, but not in the ADHD group. The opposite pattern was observed in response to reward delivery; the ADHD group demonstrated significantly greater BOLD responses in the ventral striatum bilaterally and the left dorsal striatum relative to controls. In the ADHD group, the number of current hyperactivity/impulsivity symptoms was inversely related to ventral striatal responses during reward anticipation and positively associated with responses to reward. The BOLD response patterns observed in the striatum are consistent with impaired predictive dopamine signaling in ADHD, which may explain altered reward-contingent behaviors and symptoms of ADHD. PMID:24586543

  6. Saturation thresholds of evoked neural and hemodynamic responses in awake and asleep rats

    NASA Astrophysics Data System (ADS)

    Schei, Jennifer L.; Van Nortwick, Amy S.; Meighan, Peter C.; Rector, David M.

    2011-03-01

    Neural activation generates a hemodynamic response to the localized region replenishing nutrients to the area. Changes in vigilance state have been shown to alter the vascular response where the vascular response is muted during wake compared to quiet sleep. We tested the saturation thresholds of the neurovascular response in the auditory cortex during wake and sleep by chronically implanting rats with an EEG electrode, a light emitting diode (LED, 600 nm), and photodiode to simultaneously measure evoked response potentials (ERPs) and evoked hemodynamic responses. We stimulated the cortex with a single speaker click delivered at random intervals 2-13 s at varied stimulus intensities ranging from 45-80 dB. To further test the potential for activity related saturation, we sleep deprived animals for 2, 4, or 6 hours and recorded evoked responses during the first hour recovery period. With increasing stimulus intensity, integrated ERPs and evoked hemodynamic responses increased; however the hemodynamic response approached saturation limits at a lower stimulus intensity than the ERP. With longer periods of sleep deprivation, the integrated ERPs did not change but evoked hemodynamic responses decreased. There may be physical limits in cortical blood delivery and vascular compliance, and with extended periods of neural activity during wake, vessels may approach these limits.

  7. The neural dynamics of stimulus and response conflict processing as a function of response complexity and task demands.

    PubMed

    Donohue, Sarah E; Appelbaum, Lawrence G; McKay, Cameron C; Woldorff, Marty G

    2016-04-01

    Both stimulus and response conflict can disrupt behavior by slowing response times and decreasing accuracy. Although several neural activations have been associated with conflict processing, it is unclear how specific any of these are to the type of stimulus conflict or the amount of response conflict. Here, we recorded electrical brain activity, while manipulating the type of stimulus conflict in the task (spatial [Flanker] versus semantic [Stroop]) and the amount of response conflict (two versus four response choices). Behaviorally, responses were slower to incongruent versus congruent stimuli across all task and response types, along with overall slowing for higher response-mapping complexity. The earliest incongruency-related neural effect was a short-duration frontally-distributed negativity at ~200 ms that was only present in the Flanker spatial-conflict task. At longer latencies, the classic fronto-central incongruency-related negativity 'N(inc)' was observed for all conditions, but was larger and ~100 ms longer in duration with more response options. Further, the onset of the motor-related lateralized readiness potential (LRP) was earlier for the two vs. four response sets, indicating that smaller response sets enabled faster motor-response preparation. The late positive complex (LPC) was present in all conditions except the two-response Stroop task, suggesting this late conflict-related activity is not specifically related to task type or response-mapping complexity. Importantly, across tasks and conditions, the LRP onset at or before the conflict-related N(inc), indicating that motor preparation is a rapid, automatic process that interacts with the conflict-detection processes after it has begun. Together, these data highlight how different conflict-related processes operate in parallel and depend on both the cognitive demands of the task and the number of response options.

  8. Abnormal facilitation of the response to transcranial magnetic stimulation in patients with Parkinson's disease.

    PubMed

    Valls-Solé, J; Pascual-Leone, A; Brasil-Neto, J P; Cammarota, A; McShane, L; Hallett, M

    1994-04-01

    We studied the facilitation of the motor evoked potential (MEP) elicited with transcranial magnetic stimulation by increasing the stimulus intensity and the degree of voluntary activation of the target muscle in patients with Parkinson's disease (PD) and in normal volunteers. The threshold intensity for eliciting MEPs with the muscle at rest did not differ in PD patients and normal subjects. At rest, stimuli of similar intensity, related to the individual's threshold, elicited MEPs with amplitudes consistently larger in patients than in normal subjects, although when we compared the averaged MEP amplitude across all stimulus intensities, the differences reached only borderline statistical significance. Voluntary muscle activation elicited a smaller increase in the MEP area in PD patients than in normal subjects. Increasing the degree of voluntary muscle activation at fixed stimulus intensities elicited a smaller increase of MEP amplitude, duration, and area in PD patients than in normal subjects. These results suggest that control of the excitability of the motor system is abnormal in PD patients, with enhancement of excitability at rest and weak energization during voluntary muscle activation.

  9. Bilingualism increases neural response consistency and attentional control: evidence for sensory and cognitive coupling.

    PubMed

    Krizman, Jennifer; Skoe, Erika; Marian, Viorica; Kraus, Nina

    2014-01-01

    Auditory processing is presumed to be influenced by cognitive processes - including attentional control - in a top-down manner. In bilinguals, activation of both languages during daily communication hones inhibitory skills, which subsequently bolster attentional control. We hypothesize that the heightened attentional demands of bilingual communication strengthens connections between cognitive (i.e., attentional control) and auditory processing, leading to greater across-trial consistency in the auditory evoked response (i.e., neural consistency) in bilinguals. To assess this, we collected passively-elicited auditory evoked responses to the syllable [da] in adolescent Spanish-English bilinguals and English monolinguals and separately obtained measures of attentional control and language ability. Bilinguals demonstrated enhanced attentional control and more consistent brainstem and cortical responses. In bilinguals, but not monolinguals, brainstem consistency tracked with language proficiency and attentional control. We interpret these enhancements in neural consistency as the outcome of strengthened attentional control that emerged from experience communicating in two languages.

  10. Abnormal drug responses with adrenaline on an educational paediatric simulator: the measurement of the responses and correction of the pharmacological model parameters.

    PubMed

    Tooley, M A; Lauder, G R; Lovell, A T

    2007-10-01

    A paediatric simulator (PediaSimtrade mark, Medical Education Technologies, Inc (METI), Florida, US) has been in use at the Bristol Medical Simulation Centre since early 2000. It has proved to be a very effective educational tool. The simulator is a full-sized high fidelity model of a healthy six year old child weighing 20 kg. Administration of adrenaline (epinephrine) to the simulator was found to create an unrealistic clinical response. Correction of this abnormal response was considered extremely important to ensure valid teaching material for adult learners. Comprehensive physiological measurements and dose responses for adrenaline were evaluated in the simulator under steady state conditions. The dose responses from the simulator were compared with those responses that were considered clinically appropriate by a cohort of paediatric anaesthetists. Expert opinion was utilized as no published haemodynamic data are available for adrenaline in a healthy population of children in this age group. The drug parameters were modified using the simulator drug editor. Dose responses were repeated using the modified drug model and again compared to the required responses. This process was repeated until acceptable clinical limits were achieved. The baseline responses for the drug differed significantly from the required responses. The drug model parameters were successfully modified to give the appropriate clinical responses. The improved model for the haemodynamic effects of adrenaline now provides realistic clinical responses, enabling the paediatric simulator to be a more effective educational tool.

  11. Intergroup relationships do not reduce racial bias in empathic neural responses to pain.

    PubMed

    Contreras-Huerta, Luis Sebastian; Hielscher, Emily; Sherwell, Chase S; Rens, Natalie; Cunnington, Ross

    2014-11-01

    Perceiving the pain of others activates similar neural structures to those involved in the direct experience of pain, including sensory and affective-motivational areas. Empathic responses can be modulated by race, such that stronger neural activation is elicited by the perception of pain in people of the same race compared with another race. In the present study, we aimed to identify when racial bias occurs in the time course of neural empathic responses to pain. We also investigated whether group affiliation could modulate the race effect. Using the minimal group paradigm, we assigned participants to one of two mixed-race teams. We examined event-related potentials from participants when viewing members of their own and the other team receiving painful or non-painful touch. We identified a significant racial bias in early ERP components at N1 over frontal electrodes, where Painful stimuli elicited a greater negative shift relative to Non-Painful stimuli in response to own race faces only. A long latency empathic response was also found at P3, where there was significant differentiation between Painful and Non-Painful stimuli regardless of Race or Group. There was no evidence that empathy-related brain activity was modulated by minimal group manipulation. These results support a model of empathy for pain that consists of early, automatic bias towards own-race empathic responses and a later top-down cognitive evaluation that does not differentiate between races and may ultimately lead to unbiased behaviour.

  12. Relation of obesity to neural activation in response to food commercials

    PubMed Central

    Yokum, Sonja; Stice, Eric; Harris, Jennifer L.; Brownell, Kelly D.

    2014-01-01

    Adolescents view thousands of food commercials annually, but the neural response to food advertising and its association with obesity is largely unknown. This study is the first to examine how neural response to food commercials differs from other stimuli (e.g. non-food commercials and television show) and to explore how this response may differ by weight status. The blood oxygen level-dependent functional magnetic resonance imaging activation was measured in 30 adolescents ranging from lean to obese in response to food and non-food commercials imbedded in a television show. Adolescents exhibited greater activation in regions implicated in visual processing (e.g. occipital gyrus), attention (e.g. parietal lobes), cognition (e.g. temporal gyrus and posterior cerebellar lobe), movement (e.g. anterior cerebellar cortex), somatosensory response (e.g. postcentral gyrus) and reward [e.g. orbitofrontal cortex and anterior cingulate cortex (ACC)] during food commercials. Obese participants exhibited less activation during food relative to non-food commercials in neural regions implicated in visual processing (e.g. cuneus), attention (e.g. posterior cerebellar lobe), reward (e.g. ventromedial prefrontal cortex and ACC) and salience detection (e.g. precuneus). Obese participants did exhibit greater activation in a region implicated in semantic control (e.g. medial temporal gyrus). These findings may inform current policy debates regarding the impact of food advertising to minors. PMID:23576811

  13. Placebo-Activated Neural Systems are Linked to Antidepressant Responses

    PubMed Central

    Peciña, Marta; Bohnert, Amy S. B.; Sikora, Magdalena; Avery, Erich T.; Langenecker, Scott A.; Mickey, Brian J.; Zubieta, Jon-Kar

    2016-01-01

    Importance High placebo responses have been observed across a wide range of pathologies, severely impacting drug development. Objective Here we examined neurochemical mechanisms underlying the formation of placebo effects in patients with Major Depressive Disorder (MDD). Participants Thirty-five medication-free MDD patients. Design and Intervention We performed a single-blinded two-week cross-over randomized controlled trial of two identical oral placebos (described as having either “active” or “inactive” fast-acting antidepressant-like effects) followed by a 10-week open-label treatment with a selective serotonin reuptake inhibitor (SSRI) or in some cases, another agent as clinically indicated. The volunteers were studied with PET and the μ-opioid receptor (MOR)-selective radiotracer [11C]carfentanil after each 1-week “inactive” and “active” oral placebo treatment. In addition, 1 mL of isotonic saline was administered intravenously (i.v.) within sight of the volunteer during PET scanning every 4 min over 20 min only after the 1-week active placebo treatment, with instructions that the compound may be associated with the activation of brain systems involved in mood improvement. This challenge stimulus was utilized to test the individual capacity to acutely activate endogenous opioid neurotransmision under expectations of antidepressant effect. Setting A University Health System. Main Outcomes and Measures Changes in depressive symptoms in response to “active” placebo and antidepressant. Baseline and activation measures of MOR binding. Results Higher baseline MOR binding in the nucleus accumbens (NAc) was associated with better response to antidepressant treatment (r=0.48; p=0.02). Reductions in depressive symptoms after 1-week of “active” placebo treatment, compared to the “inactive”, were associated with increased placebo-induced μ-opioid neurotransmission in a network of regions implicated in emotion, stress regulation, and the

  14. Neural Responses to Heartbeats in the Default Network Encode the Self in Spontaneous Thoughts

    PubMed Central

    Babo-Rebelo, Mariana; Richter, Craig G.

    2016-01-01

    The default network (DN) has been consistently associated with self-related cognition, but also to bodily state monitoring and autonomic regulation. We hypothesized that these two seemingly disparate functional roles of the DN are functionally coupled, in line with theories proposing that selfhood is grounded in the neural monitoring of internal organs, such as the heart. We measured with magnetoencephalograhy neural responses evoked by heartbeats while human participants freely mind-wandered. When interrupted by a visual stimulus at random intervals, participants scored the self-relatedness of the interrupted thought. They evaluated their involvement as the first-person perspective subject or agent in the thought (“I”), and on another scale to what degree they were thinking about themselves (“Me”). During the interrupted thought, neural responses to heartbeats in two regions of the DN, the ventral precuneus and the ventromedial prefrontal cortex, covaried, respectively, with the “I” and the “Me” dimensions of the self, even at the single-trial level. No covariation between self-relatedness and peripheral autonomic measures (heart rate, heart rate variability, pupil diameter, electrodermal activity, respiration rate, and phase) or alpha power was observed. Our results reveal a direct link between selfhood and neural responses to heartbeats in the DN and thus directly support theories grounding selfhood in the neural monitoring of visceral inputs. More generally, the tight functional coupling between self-related processing and cardiac monitoring observed here implies that, even in the absence of measured changes in peripheral bodily measures, physiological and cognitive functions have to be considered jointly in the DN. SIGNIFICANCE STATEMENT The default network (DN) has been consistently associated with self-processing but also with autonomic regulation. We hypothesized that these two functions could be functionally coupled in the DN, inspired by

  15. Neural Responses to Central and Peripheral Objects in the Lateral Occipital Cortex

    PubMed Central

    Wang, Bin; Guo, Jiayue; Yan, Tianyi; Ohno, Seiichiro; Kanazawa, Susumu; Huang, Qiang; Wu, Jinglong

    2016-01-01

    Human object recognition and classification depend on the retinal location where the object is presented and decrease as eccentricity increases. The lateral occipital complex (LOC) is thought to be preferentially involved in the processing of objects, and its neural responses exhibit category biases to objects presented in the central visual field. However, the nature of LOC neural responses to central and peripheral objects remains largely unclear. In the present study, we used functional magnetic resonance imaging (fMRI) and a wide-view presentation system to investigate neural responses to four categories of objects (faces, houses, animals, and cars) in the primary visual cortex (V1) and the lateral visual cortex, including the LOC and the retinotopic areas LO-1 and LO-2. In these regions, the neural responses to objects decreased as the distance between the location of presentation and center fixation increased, which is consistent with the diminished perceptual ability that was found for peripherally presented images. The LOC and LO-2 exhibited significantly positive neural responses to all eccentricities (0–55°), but LO-1 exhibited significantly positive responses only to central eccentricities (0–22°). By measuring the ratio relative to V1 (RRV1), we further demonstrated that eccentricity, category and the interaction between them significantly affected neural processing in these regions. LOC, LO-1, and LO-2 exhibited larger RRV1s when stimuli were presented at an eccentricity of 0° compared to when they were presented at the greater eccentricities. In LOC and LO-2, the RRV1s for images of faces, animals and cars showed an increasing trend when the images were presented at eccentricities of 11 to 33°. However, the RRV1s for houses showed a decreasing trend in LO-1 and no difference in the LOC and LO-2. We hypothesize, that when houses and the images in the other categories were presented in the peripheral visual field, they were processed via

  16. Neural Responses to Central and Peripheral Objects in the Lateral Occipital Cortex.

    PubMed

    Wang, Bin; Guo, Jiayue; Yan, Tianyi; Ohno, Seiichiro; Kanazawa, Susumu; Huang, Qiang; Wu, Jinglong

    2016-01-01

    Human object recognition and classification depend on the retinal location where the object is presented and decrease as eccentricity increases. The lateral occipital complex (LOC) is thought to be preferentially involved in the processing of objects, and its neural responses exhibit category biases to objects presented in the central visual field. However, the nature of LOC neural responses to central and peripheral objects remains largely unclear. In the present study, we used functional magnetic resonance imaging (fMRI) and a wide-view presentation system to investigate neural responses to four categories of objects (faces, houses, animals, and cars) in the primary visual cortex (V1) and the lateral visual cortex, including the LOC and the retinotopic areas LO-1 and LO-2. In these regions, the neural responses to objects decreased as the distance between the location of presentation and center fixation increased, which is consistent with the diminished perceptual ability that was found for peripherally presented images. The LOC and LO-2 exhibited significantly positive neural responses to all eccentricities (0-55°), but LO-1 exhibited significantly positive responses only to central eccentricities (0-22°). By measuring the ratio relative to V1 (RRV1), we further demonstrated that eccentricity, category and the interaction between them significantly affected neural processing in these regions. LOC, LO-1, and LO-2 exhibited larger RRV1s when stimuli were presented at an eccentricity of 0° compared to when they were presented at the greater eccentricities. In LOC and LO-2, the RRV1s for images of faces, animals and cars showed an increasing trend when the images were presented at eccentricities of 11 to 33°. However, the RRV1s for houses showed a decreasing trend in LO-1 and no difference in the LOC and LO-2. We hypothesize, that when houses and the images in the other categories were presented in the peripheral visual field, they were processed via different

  17. Neural responses to kindness and malevolence differ in illness and recovery in women with anorexia nervosa.

    PubMed

    McAdams, Carrie J; Lohrenz, Terry; Montague, P Read

    2015-12-01

    In anorexia nervosa, problems with social relationships contribute to illness, and improvements in social support are associated with recovery. Using the multiround trust game and 3T MRI, we compare neural responses in a social relationship in three groups of women: women with anorexia nervosa, women in long-term weight recovery from anorexia nervosa, and healthy comparison women. Surrogate markers related to social signals in the game were computed each round to assess whether the relationship was improving (benevolence) or deteriorating (malevolence) for each subject. Compared with healthy women, neural responses to benevolence were diminished in the precuneus and right angular gyrus in both currently-ill and weight-recovered subjects with anorexia, but neural responses to malevolence differed in the left fusiform only in currently-ill subjects. Next, using a whole-brain regression, we identified an office assessment, the positive personalizing bias, that was inversely correlated with neural activity in the occipital lobe, the precuneus and posterior cingulate, the bilateral temporoparietal junctions, and dorsal anterior cingulate, during benevolence for all groups of subjects. The positive personalizing bias is a self-report measure that assesses the degree with which a person attributes positive experiences to other people. These data suggest that problems in perceiving kindness may be a consistent trait related to the development of anorexia nervosa, whereas recognizing malevolence may be related to recovery. Future work on social brain function, in both healthy and psychiatric populations, should consider positive personalizing biases as a possible marker of neural differences related to kindness perception.

  18. Neural Network and Response Surface Methodology for Rocket Engine Component Optimization

    NASA Technical Reports Server (NTRS)

    Vaidyanathan, Rajkumar; Papita, Nilay; Shyy, Wei; Tucker, P. Kevin; Griffin, Lisa W.; Haftka, Raphael; Fitz-Coy, Norman; McConnaughey, Helen (Technical Monitor)

    2000-01-01

    The goal of this work is to compare the performance of response surface methodology (RSM) and two types of neural networks (NN) to aid preliminary design of two rocket engine components. A data set of 45 training points and 20 test points obtained from a semi-empirical model based on three design variables is used for a shear coaxial injector element. Data for supersonic turbine design is based on six design variables, 76 training, data and 18 test data obtained from simplified aerodynamic analysis. Several RS and NN are first constructed using the training data. The test data are then employed to select the best RS or NN. Quadratic and cubic response surfaces. radial basis neural network (RBNN) and back-propagation neural network (BPNN) are compared. Two-layered RBNN are generated using two different training algorithms, namely solverbe and solverb. A two layered BPNN is generated with Tan-Sigmoid transfer function. Various issues related to the training of the neural networks are addressed including number of neurons, error goals, spread constants and the accuracy of different models in representing the design space. A search for the optimum design is carried out using a standard gradient-based optimization algorithm over the response surfaces represented by the polynomials and trained neural networks. Usually a cubic polynominal performs better than the quadratic polynomial but exceptions have been noticed. Among the NN choices, the RBNN designed using solverb yields more consistent performance for both engine components considered. The training of RBNN is easier as it requires linear regression. This coupled with the consistency in performance promise the possibility of it being used as an optimization strategy for engineering design problems.

  19. Neural responses to electrical stimulation on patterned silk films.

    PubMed

    Hronik-Tupaj, Marie; Raja, Waseem Khan; Tang-Schomer, Min; Omenetto, Fiorenzo G; Kaplan, David L

    2013-09-01

    Peripheral nerve injury is a critical issue for patients with trauma. Following injury, incomplete axon regeneration or misguided axon innervation into tissue will result in loss of sensory and motor functions. The objective of this study was to examine axon outgrowth and axon alignment in response to surface patterning and electrical stimulation. To accomplish our objective, metal electrodes with dimensions of 1.5 mm × 4 cm, were sputter coated onto micropatterned silk protein films, with surface grooves 3.5 μm wide × 500 nm deep. P19 neurons were seeded on the patterned electronic silk films and stimulated at 120 mV, 1 kHz, for 45 min each day for 7 days. Responses were compared with neurons on flat electronic silk films, patterned silk films without stimulation, and flat silk films without stimulation. Significant alignment was found on the patterned film groups compared with the flat film groups. Axon outgrowth was greater (p < 0.05) on electronic films on days 5 and 7 compared with the unstimulated groups. In conclusion, electrical stimulation, at 120 mV, 1 kHz, for 45 min daily, in addition to surface patterning, of 3.5 μm wide × 500 nm deep grooves, offered control of nerve axon outgrowth and alignment.

  20. Behavioral and genetic correlates of the neural response to infant crying among human fathers

    PubMed Central

    Mascaro, Jennifer S.; Hackett, Patrick D.; Gouzoules, Harold; Lori, Adriana

    2014-01-01

    Although evolution has shaped human infant crying and the corresponding response from caregivers, there is marked variation in paternal involvement and caretaking behavior, highlighting the importance of understanding the neurobiology supporting optimal paternal responses to cries. We explored the neural response to infant cries in fathers of children aged 1–2, and its relationship with hormone levels, variation in the androgen receptor (AR) gene, parental attitudes and parental behavior. Although number of AR CAG trinucleotide repeats was positively correlated with neural activity in brain regions important for empathy (anterior insula and inferior frontal gyrus), restrictive attitudes were inversely correlated with neural activity in these regions and with regions involved with emotion regulation (orbitofrontal cortex). Anterior insula activity had a non-linear relationship with paternal caregiving, such that fathers with intermediate activation were most involved. These results suggest that restrictive attitudes may be associated with decreased empathy and emotion regulation in response to a child in distress, and that moderate anterior insula activity reflects an optimal level of arousal that supports engaged fathering. PMID:24336349

  1. Auditory Responses to Electric and Infrared Neural Stimulation of the Rat Cochlear Nucleus

    PubMed Central

    Verma, Rohit; Guex, Amelie A.; Hancock, Kenneth E.; Durakovic, Nedim; McKay, Colette M.; Slama, Michaël C. C.; Brown, M. Christian; Lee, Daniel J.

    2014-01-01

    In an effort to improve the auditory brainstem implant, a prosthesis in which user outcomes are modest, we applied electric and infrared neural stimulation (INS) to the cochlear nucleus in a rat animal model. Electric stimulation evoked regions of neural activation in the inferior colliculus and short-latency, multipeaked auditory brainstem responses (ABRs). Pulsed INS, delivered to the surface of the cochlear nucleus via an optical fiber, evoked broad neural activation in the inferior colliculus. Strongest responses were recorded when the fiber was placed at lateral positions on the cochlear nucleus, close to the temporal bone. INS-evoked ABRs were multipeaked but longer in latency than those for electric stimulation; they resembled the responses to acoustic stimulation. After deafening, responses to electric stimulation persisted, whereas those to INS disappeared, consistent with a reported “optophonic” effect, a laser-induced acoustic artifact. Thus, for deaf individuals who use the auditory brainstem implant, INS alone did not appear promising as a new approach. PMID:24508368

  2. The neural basis of responsive caregiving behaviour: Investigating temporal dynamics within the parental brain.

    PubMed

    Young, Katherine S; Parsons, Christine E; Stein, Alan; Vuust, Peter; Craske, Michelle G; Kringelbach, Morten L

    2016-09-06

    Whether it is the sound of a distressed cry or the image of a cute face, infants capture our attention. Parents and other adults alike are drawn into interactions to engage in play, nurturance and provide care. Responsive caregiving behaviour is a key feature of the parent-infant relationship, forming the foundation upon which attachment is built. Infant cues are considered to be 'innate releasers' or 'motivational entities' eliciting responses in nearby adults (Lorenz 1943; Murray, 1979) [42,43]. Through the advent of modern neuroimaging, we are beginning to understand the initiation of this motivational state at the neurobiological level. In this review, we first describe a current model of the 'parental brain', based on functional MRI studies assessing neural responses to infant cues. Next, we discuss recent findings from temporally sensitive techniques (magneto- and electroencephalography) that illuminate the temporal dynamics of this neural network. We focus on converging evidence highlighting a specific role for the orbitofrontal cortex in supporting rapid orienting responses to infant cues. In addition, we consider to what extent these neural processes are tied to parenthood, or whether they might be present universally in all adults. We highlight important avenues for future research, including utilizing multiple levels of analysis for a comprehensive understanding of adaptive caregiving behaviour. Finally, we discuss how this research can help us understand disrupted parent-infant relationships, such as in situations where parents' contingent responding to infant cues is disrupted; for example, in parental depression or anxiety where cognitive attentional processes are disrupted.

  3. Girls’ Challenging Social Experiences in Early Adolescence Predict Neural Response to Rewards and Depressive Symptoms1

    PubMed Central

    Casement, Melynda D.; Guyer, Amanda E.; Hipwell, Alison; McAloon, Rose L.; Hoffmann, Amy M.; Keenan, Kathryn; Forbes, Erika E.

    2014-01-01

    Developmental models of psychopathology posit that exposure to social stressors may confer risk for depression in adolescent girls by disrupting neural reward circuitry. The current study tested this hypothesis by examining the relationship between early adolescent social stressors and later neural reward processing and depressive symptoms. Participants were 120 girls from an ongoing longitudinal study of precursors to depression across adolescent development. Low parental warmth, peer victimization, and depressive symptoms were assessed when the girls were 11 and 12 years old, and participants completed a monetary reward guessing fMRI task and assessment of depressive symptoms at age 16. Results indicate that low parental warmth was associated with increased response to potential rewards in the medial prefrontal cortex (mPFC), striatum, and amygdala, whereas peer victimization was associated with decreased response to potential rewards in the mPFC. Furthermore, concurrent depressive symptoms were associated with increased reward anticipation response in mPFC and striatal regions that were also associated with early adolescent psychosocial stressors, with mPFC and striatal response mediating the association between social stressors and depressive symptoms. These findings are consistent with developmental models that emphasize the adverse impact of early psychosocial stressors on neural reward processing and risk for depression in adolescence. PMID:24397999

  4. Expectation and surprise determine neural population responses in the ventral visual stream.

    PubMed

    Egner, Tobias; Monti, Jim M; Summerfield, Christopher

    2010-12-08

    Visual cortex is traditionally viewed as a hierarchy of neural feature detectors, with neural population responses being driven by bottom-up stimulus features. Conversely, "predictive coding" models propose that each stage of the visual hierarchy harbors two computationally distinct classes of processing unit: representational units that encode the conditional probability of a stimulus and provide predictions to the next lower level; and error units that encode the mismatch between predictions and bottom-up evidence, and forward prediction error to the next higher level. Predictive coding therefore suggests that neural population responses in category-selective visual regions, like the fusiform face area (FFA), reflect a summation of activity related to prediction ("face expectation") and prediction error ("face surprise"), rather than a homogenous feature detection response. We tested the rival hypotheses of the feature detection and predictive coding models by collecting functional magnetic resonance imaging data from the FFA while independently varying both stimulus features (faces vs houses) and subjects' perceptual expectations regarding those features (low vs medium vs high face expectation). The effects of stimulus and expectation factors interacted, whereby FFA activity elicited by face and house stimuli was indistinguishable under high face expectation and maximally differentiated under low face expectation. Using computational modeling, we show that these data can be explained by predictive coding but not by feature detection models, even when the latter are augmented with attentional mechanisms. Thus, population responses in the ventral visual stream appear to be determined by feature expectation and surprise rather than by stimulus features per se.

  5. Associations between maternal negative affect and adolescent's neural response to peer evaluation.

    PubMed

    Tan, Patricia Z; Lee, Kyung Hwa; Dahl, Ronald E; Nelson, Eric E; Stroud, Laura J; Siegle, Greg J; Morgan, Judith K; Silk, Jennifer S

    2014-04-01

    Parenting is often implicated as a potential source of individual differences in youths' emotional information processing. The present study examined whether parental affect is related to an important aspect of adolescent emotional development, response to peer evaluation. Specifically, we examined relations between maternal negative affect, observed during parent-adolescent discussion of an adolescent-nominated concern with which s/he wants parental support, and adolescent neural responses to peer evaluation in 40 emotionally healthy and depressed adolescents. We focused on a network of ventral brain regions involved in affective processing of social information: the amygdala, anterior insula, nucleus accumbens, and subgenual anterior cingulate, as well as the ventrolateral prefrontal cortex. Maternal negative affect was not associated with adolescent neural response to peer rejection. However, longer durations of maternal negative affect were associated with decreased responsivity to peer acceptance in the amygdala, left anterior insula, subgenual anterior cingulate, and left nucleus accumbens. These findings provide some of the first evidence that maternal negative affect is associated with adolescents' neural processing of social rewards. Findings also suggest that maternal negative affect could contribute to alterations in affective processing, specifically, dampening the saliency and/or reward of peer interactions during adolescence.

  6. Developmental effects of oxytocin on neural activation and neuropeptide release in response to social stimuli.

    PubMed

    Kramer, Kristin M; Choe, Christina; Carter, C Sue; Cushing, Bruce S

    2006-02-01

    Previous studies have revealed that the neuropeptide hormone oxytocin (OT) has developmental effects on subsequent social behavior and on mechanisms underlying social behavior such as OT neurons and estrogen receptor alpha. This suggests that OT might also have developmental effects on neural responses to social stimuli. This was tested in socially monogamous prairie voles (Microtus ochrogaster) by manipulating OT on the first day of life and then assessing the response to a heterosexual pairing in adulthood. The response to cohabitation was assessed by quantifying neural activation in regions of the brain associated with sociosexual behavior and anxiety using c-Fos immunoreactivity. Additionally, immunocytochemistry was used to label OT and vasopressin neurons and plasma was assayed for both neuropeptides. Treatment effects were evident in females, but not in males. Blockade of OT receptors with an OT antagonist on the first day of life resulted in neural activation of the central amygdala in response to a pairing with a novel male in adulthood. The central amygdala does not normally express c-Fos after a heterosexual pairing in reproductively naïve prairie voles. Treatment effects also were observed in vasopressin immunoreactivity in the SON with OT-treated females showing a decrease.

  7. Nanoscale Properties of Neural Cell Prosthetic and Astrocyte Response

    NASA Astrophysics Data System (ADS)

    Flowers, D. A.; Ayres, V. M.; Delgado-Rivera, R.; Ahmed, I.; Meiners, S. A.

    2009-03-01

    Preliminary data from in-vivo investigations (rat model) suggest that a nanofiber prosthetic device of fibroblast growth factor-2 (FGF-2)-modified nanofibers can correctly guide regenerating axons across an injury gap with aligned functional recovery. Scanning Probe Recognition Microscopy (SPRM) with auto-tracking of individual nanofibers is used for investigation of the key nanoscale properties of the nanofiber prosthetic device for central nervous system tissue engineering and repair. The key properties under SPRM investigation include nanofiber stiffness and surface roughness, nanofiber curvature, nanofiber mesh density and porosity, and growth factor presentation and distribution. Each of these factors has been demonstrated to have global effects on cell morphology, function, proliferation, morphogenesis, migration, and differentiation. The effect of FGF-2 modification on the key nanoscale properties is investigated. Results from the nanofiber prosthetic properties investigations are correlated with astrocyte response to unmodified and FGF-2 modified scaffolds, using 2D planar substrates as a control.

  8. Psychophysiological stress testing in postinfarction patients. Psychological correlates of cardiovascular arousal and abnormal cardiac responses.

    PubMed

    Zotti, A M; Bettinardi, O; Soffiantino, F; Tavazzi, L; Steptoe, A

    1991-04-01

    The psychophysiological responses to two mental stress tests (mental arithmetic and an interactive concentration task) were assessed in 168 unmedicated, male, postinfarction patients 36-69 years old. Patients also completed a standard battery of psychological tests. Psychophysiological responses were generally unrelated to age and education. Comparison of patients scoring high (more than 75%) and low (less than 25%) relative to the normal population on psychological measures indicated that heart rate and blood pressure responses to mental stress tests were significantly greater in those reporting low than in those reporting high neuroticism. The study population was subsequently divided into high, medium, and low cardiovascular responders on the basis of rate-pressure product reactions to the two stress tests. The three cardiovascular response groups did not differ in age, interval between myocardial infarction and stress testing, ejection fraction, incidence of exercise-induced ischemia, or ischemic signs during Holter monitoring. However, the high cardiovascular responders were more likely to manifest possible or definite electrocardiographic signs of ischemia or significant arrhythmia during mental stress testing than were the medium or low cardiovascular responders (50% versus 19.6% and 7%, respectively). High cardiovascular responders also reported lower levels of trait anxiety, neuroticism, psychophysiological symptoms, and depression.

  9. A developmental study on the neural circuitry mediating response flexibility in bipolar disorder.

    PubMed

    Weathers, Judah; Brotman, Melissa A; Deveney, Christen M; Kim, Pilyoung; Zarate, Carlos; Fromm, Stephen; Pine, Daniel; Leibenluft, Ellen

    2013-10-30

    Cross-sectional neuroimaging studies are an important first step in examining developmental differences in brain function between adults and youth with bipolar disorder (BD). Impaired response flexibility may contribute to reduced ability to modify goal-directed behavior in BD appropriately. We compared neural circuitry mediating this process in child (CBD) vs. adult BD (ABD) and age-matched healthy subjects. fMRI data from 15 CBD, 23 ABD, 20 healthy children, and 27 healthy adults were acquired during a response flexibility paradigm, a task where subjects inhibit a prepotent response and execute an alternative response. When successfully executing an alternate response, CBD showed frontal, parietal, and temporal hyperactivation relative to healthy children and ABD, while ABD hypoactivated these regions relative to healthy adults. Previous studies of response flexibility in healthy volunteers revealed frontal, temporal, and parietal cortex hyperactivation in children and hypoactivation in adults. Relative to age-matched healthy subjects, we found hyperactivation in these regions in CBD and hypoactivation in ABD. This suggests that our findings in patients may represent the extreme extension of the age-related response flexibility activation differences found in healthy subjects. Future studies should use longitudinal fMRI to examine the developmental trajectory of the neural circuitry mediating response flexibility in BD.

  10. Abnormal hemodynamic response to forepaw stimulation in rat brain after cocaine injection

    NASA Astrophysics Data System (ADS)

    Chen, Wei; Park, Kicheon; Choi, Jeonghun; Pan, Yingtian; Du, Congwu

    2015-03-01

    Simultaneous measurement of hemodynamics is of great importance to evaluate the brain functional changes induced by brain diseases such as drug addiction. Previously, we developed a multimodal-imaging platform (OFI) which combined laser speckle contrast imaging with multi-wavelength imaging to simultaneously characterize the changes in cerebral blood flow (CBF), oxygenated- and deoxygenated- hemoglobin (HbO and HbR) from animal brain. Recently, we upgraded our OFI system that enables detection of hemodynamic changes in response to forepaw electrical stimulation to study potential brain activity changes elicited by cocaine. The improvement includes 1) high sensitivity to detect the cortical response to single forepaw electrical stimulation; 2) high temporal resolution (i.e., 16Hz/channel) to resolve dynamic variations in drug-delivery study; 3) high spatial resolution to separate the stimulation-evoked hemodynamic changes in vascular compartments from those in tissue. The system was validated by imaging the hemodynamic responses to the forepaw-stimulations in the somatosensory cortex of cocaine-treated rats. The stimulations and acquisitions were conducted every 2min over 40min, i.e., from 10min before (baseline) to 30min after cocaine challenge. Our results show that the HbO response decreased first (at ~4min) followed by the decrease of HbR response (at ~6min) after cocaine, and both did not fully recovered for over 30min. Interestingly, while CBF decreased at 4min, it partially recovered at 18min after cocaine administration. The results indicate the heterogeneity of cocaine's effects on vasculature and tissue metabolism, demonstrating the unique capability of optical imaging for brain functional studies.

  11. Oscillatory neural responses evoked by natural vestibular stimuli in humans.

    PubMed

    Gale, Steven; Prsa, Mario; Schurger, Aaron; Gay, Annietta; Paillard, Aurore; Herbelin, Bruno; Guyot, Jean-Philippe; Lopez, Christophe; Blanke, Olaf

    2016-03-01

    While there have been numerous studies of the vestibular system in mammals, less is known about the brain mechanisms of vestibular processing in humans. In particular, of the studies that have been carried out in humans over the last 30 years, none has investigated how vestibular stimulation (VS) affects cortical oscillations. Here we recorded high-density electroencephalography (EEG) in healthy human subjects and a group of bilateral vestibular loss patients (BVPs) undergoing transient and constant-velocity passive whole body yaw rotations, focusing our analyses on the modulation of cortical oscillations in response to natural VS. The present approach overcame significant technical challenges associated with combining natural VS with human electrophysiology and reveals that both transient and constant-velocity VS are associated with a prominent suppression of alpha power (8-13 Hz). Alpha band suppression was localized over bilateral temporo-parietal scalp regions, and these alpha modulations were significantly smaller in BVPs. We propose that suppression of oscillations in the alpha band over temporo-parietal scalp regions reflects cortical vestibular processing, potentially comparable with alpha and mu oscillations in the visual and sensorimotor systems, respectively, opening the door to the investigation of human cortical processing under various experimental conditions during natural VS.

  12. Neural responses to grammatically and lexically degraded speech

    PubMed Central

    Bautista, Alexa; Wilson, Stephen M.

    2016-01-01

    Linguistic stimuli that are degraded in various ways have been used in neuroimaging studies to uncover distinct roles for different brain regions involved in processing language. In order to identify brain regions differentially involved in grammatical and lexical processing, we spectrally rotated specific morphemes and manipulated morpheme order to create speech stimuli that were degraded either grammatically or lexically, yet were matched in intelligibility. Twelve healthy participants were scanned with functional MRI as they listened to the grammatically and lexically degraded stimuli, interspersed with clear stimuli in the context of a familiar narrative. Contrary to our expectations, we did not find any brain regions that were selectively sensitive to grammatical or lexical degradation. However, compared to previous studies, there was less signal reduction than anticipated in response to degradation of either type. These findings may reflect increased attention to the degraded stimuli due to the familiar narrative context, since attention to degraded speech has been shown to attenuate the signal decreases typically associated with reduced intelligibility. PMID:27525290

  13. Behavioral and Electrophysiological Responses Evoked by Chronic Infrared Neural Stimulation of the Cochlea

    PubMed Central

    Matic, Agnella Izzo; Robinson, Alan M.; Young, Hunter K.; Badofsky, Ben; Rajguru, Suhrud M.; Stock, Stuart; Richter, Claus-Peter

    2013-01-01

    Infrared neural stimulation (INS) has been proposed as a novel method for neural stimulation. In order for INS to translate to clinical use, which would involve the use of implanted devices over years or decades, the efficacy and safety of chronic INS needs to be determined. We examined a population of cats that were chronically implanted with an optical fiber to stimulate the cochlea with infrared radiation, the first known chronic application of INS. Through behavioral responses, the cats demonstrate that stimulation occurs and a perceptual event results. Long-term stimulation did not result in a change in the electrophysiological responses, either optically-evoked or acoustically-evoked. Spiral ganglion neuron counts and post implantation tissue growth, which was localized at the optical fiber, were similar in chronically stimulated and sham implanted cochleae. Results from chronic INS experiments in the cat cochlea support future work toward INS-based neuroprostheses for humans. PMID:23505466

  14. Prostate cancer cell response to paclitaxel is affected by abnormally expressed securin PTTG1.

    PubMed

    Castilla, Carolina; Flores, M Luz; Medina, Rafael; Pérez-Valderrama, Begoña; Romero, Francisco; Tortolero, María; Japón, Miguel A; Sáez, Carmen

    2014-10-01

    PTTG1 protein, the human securin, has a central role in sister chromatid separation during mitosis, and its altered expression has been reported in many tumor types. Paclitaxel is a widely used chemotherapeutic drug, whose mechanism of action is related to its ability to arrest cells in mitosis and the subsequent induction of the intrinsic apoptotic pathway. By using two prostate cancer cell lines with different responses to paclitaxel treatment, we have identified two situations in which PTTG1 influences cell fate differentially. In slippage-prone PC3 cells, both PTTG1 downregulation and overexpression induce an increase in mitotic cells that is associated with diminished apoptosis after paclitaxel treatment. In LNCaP cells, however, PTTG1 downregulation prevents mitotic entry and, subsequently, inhibits mitosis-associated, paclitaxel-induced apoptosis. In contrast, PTTG1 overexpression induces an increase in mitotic cells and apoptosis after paclitaxel treatment. We have also identified a role for Mcl-1 protein in preventing apoptosis during mitosis in PC3 cells, as simultaneous PTTG1 and Mcl-1 silencing enhances mitosis-associated apoptosis after paclitaxel treatment. The finding that a more efficient mitotic arrest alone in PC3 cells is not enough to increase apoptosis was also confirmed with the observation that a selected paclitaxel-resistant PC3 cell line showed an apoptosis-resistant phenotype associated with increased mitosis upon paclitaxel treatment. These findings could contribute to identify putative responsive and nonresponsive cells and help us to approach incomplete responses to paclitaxel in the clinical setting.

  15. Alveolar abnormalities

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/001093.htm Alveolar abnormalities To use the sharing features on this page, please enable JavaScript. Alveolar abnormalities are changes in the tiny air sacs in ...

  16. Nail abnormalities

    MedlinePlus

    Beau's lines; Fingernail abnormalities; Spoon nails; Onycholysis; Leukonychia; Koilonychia; Brittle nails ... 2012:chap 71. Zaiac MN, Walker A. Nail abnormalities associated with systemic pathologies. Clin Dermatol . 2013;31: ...

  17. A computational relationship between thalamic sensory neural responses and contrast perception.

    PubMed

    Jiang, Yaoguang; Purushothaman, Gopathy; Casagrande, Vivien A

    2015-01-01

    Uncovering the relationship between sensory neural responses and perceptual decisions remains a fundamental problem in neuroscience. Decades of experimental and modeling work in the sensory cortex have demonstrated that a perceptual decision pool is usually composed of tens to hundreds of neurons, the responses of which are significantly correlated not only with each other, but also with the behavioral choices of an animal. Few studies, however, have measured neural activity in the sensory thalamus of awake, behaving animals. Therefore, it remains unclear how many thalamic neurons are recruited and how the information from these neurons is pooled at subsequent cortical stages to form a perceptual decision. In a previous study we measured neural activity in the macaque lateral geniculate nucleus (LGN) during a two alternative forced choice (2AFC) contrast detection task, and found that single LGN neurons were significantly correlated with the monkeys' behavioral choices, despite their relatively poor contrast sensitivity and a lack of overall interneuronal correlations. We have now computationally tested a number of specific hypotheses relating these measured LGN neural responses to the contrast detection behavior of the animals. We modeled the perceptual decisions with different numbers of neurons and using a variety of pooling/readout strategies, and found that the most successful model consisted of about 50-200 LGN neurons, with individual neurons weighted differentially according to their signal-to-noise ratios (quantified as d-primes). These results supported the hypothesis that in contrast detection the perceptual decision pool consists of multiple thalamic neurons, and that the response fluctuations in these neurons can influence contrast perception, with the more sensitive thalamic neurons likely to exert a greater influence.

  18. Cellular Neural Network Models of Growth and Immune of Effector Cells Response to Cancer

    NASA Astrophysics Data System (ADS)

    Su, Yongmei; Min, Lequan

    Four reaction-diffusion cellular neural network (R-D CNN) models are set up based on the differential equation models for the growths of effector cells and cancer cells, and the model of the immune response to cancer proposed by Allison et al. The CNN models have different reaction-diffusion coefficients and coupling parameters. The R-D CNN models may provide possible quantitative interpretations, and are good in agreement with the in vitro experiment data reported by Allison et al.

  19. A face a mother could love: depression-related maternal neural responses to infant emotion faces.

    PubMed

    Laurent, Heidemarie K; Ablow, Jennifer C

    2013-01-01

    Depressed mothers show negatively biased responses to their infants' emotional bids, perhaps due to faulty processing of infant cues. This study is the first to examine depression-related differences in mothers' neural response to their own infant's emotion faces, considering both effects of perinatal depression history and current depressive symptoms. Primiparous mothers (n = 22), half of whom had a history of major depressive episodes (with one episode occurring during pregnancy and/or postpartum), were exposed to images of their own and unfamiliar infants' joy and distress faces during functional neuroimaging. Group differences (depression vs. no-depression) and continuous effects of current depressive symptoms were tested in relation to neural response to own infant emotion faces. Compared to mothers with no psychiatric diagnoses, those with depression showed blunted responses to their own infant's distress faces in the dorsal anterior cingulate cortex. Mothers with higher levels of current symptomatology showed reduced responses to their own infant's joy faces in the orbitofrontal cortex and insula. Current symptomatology also predicted lower responses to own infant joy-distress in left-sided prefrontal and insula/striatal regions. These deficits in self-regulatory and motivational response circuits may help explain parenting difficulties in depressed mothers.

  20. Forebrain and brain stem neural circuits contribute to altered sympathetic responses to heating in senescent rats.

    PubMed

    Kenney, Michael J; Fels, Richard J

    2003-11-01

    Acute heating in young rats increases visceral sympathetic nerve discharge (SND); however, renal and splanchnic SND responses to hyperthermia are attenuated in senescent compared with young Fischer 344 (F344) rats (Kenney MJ and Fels RJ. Am J Physiol Regul Integr Comp Physiol 283: R513-R520, 2002). Central mechanisms by which aging alters visceral SND responses to heating are unknown. We tested the hypothesis that forebrain neural circuits are involved in suppressing sympathoexcitatory responses to heating in chloralose-anesthetized, senescent F344 rats. Renal and splanchnic SND responses to increased (38 degrees C-41 degrees C) internal temperature were determined in midbrain-transected (MT) and sham-MT young (3-mo-old), mature (12-mo-old), and senescent (24-mo-old) F344 rats and in cervical-transected (CT) and sham-CT senescent rats. Renal SND remained unchanged during heating in MT and sham-MT senescent rats but was increased in CT senescent rats. Splanchnic SND responses to heating were higher in MT vs. sham-MT senescent rats and in CT vs. MT senescent rats. SND responses to heating were similar in MT and sham-MT young and mature rats. Mean arterial pressure (MAP) was increased during heating in MT but not in sham-MT senescent rats, whereas heating-induced increases in MAP were higher in sham-MT vs. MT young rats. These data suggest that in senescent rats suppression of splanchnic SND to heating involves forebrain and brain stem neural circuits, whereas renal suppression is mediated solely by brain stem neural circuits. These results support the concept that aging alters the functional organization of pathways regulating SND and arterial blood pressure responses to acute heating.

  1. Modelling the perceptual similarity of facial expressions from image statistics and neural responses.

    PubMed

    Sormaz, Mladen; Watson, David M; Smith, William A P; Young, Andrew W; Andrews, Timothy J

    2016-04-01

    The ability to perceive facial expressions of emotion is essential for effective social communication. We investigated how the perception of facial expression emerges from the image properties that convey this important social signal, and how neural responses in face-selective brain regions might track these properties. To do this, we measured the perceptual similarity between expressions of basic emotions, and investigated how this is reflected in image measures and in the neural response of different face-selective regions. We show that the perceptual similarity of different facial expressions (fear, anger, disgust, sadness, happiness) can be predicted by both surface and feature shape information in the image. Using block design fMRI, we found that the perceptual similarity of expressions could also be predicted from the patterns of neural response in the face-selective posterior superior temporal sulcus (STS), but not in the fusiform face area (FFA). These results show that the perception of facial expression is dependent on the shape and surface properties of the image and on the activity of specific face-selective regions.

  2. Tympanal mechanics and neural responses in the ears of a noctuid moth

    NASA Astrophysics Data System (ADS)

    Ter Hofstede, Hannah M.; Goerlitz, Holger R.; Montealegre-Z, Fernando; Robert, Daniel; Holderied, Marc W.

    2011-12-01

    Ears evolved in many groups of moths to detect the echolocation calls of predatory bats. Although the neurophysiology of bat detection has been intensively studied in moths for decades, the relationship between sound-induced movement of the noctuid tympanic membrane and action potentials in the auditory sensory cells (A1 and A2) has received little attention. Using laser Doppler vibrometry, we measured the velocity and displacement of the tympanum in response to pure tone pulses for moths that were intact or prepared for neural recording. When recording from the auditory nerve, the displacement of the tympanum at the neural threshold remained constant across frequencies, whereas velocity varied with frequency. This suggests that the key biophysical parameter for triggering action potentials in the sensory cells of noctuid moths is tympanum displacement, not velocity. The validity of studies on the neurophysiology of moth hearing rests on the assumption that the dissection and recording procedures do not affect the biomechanics of the ear. There were no consistent differences in tympanal velocity or displacement when moths were intact or prepared for neural recordings for sound levels close to neural threshold, indicating that this and other neurophysiological studies provide good estimates of what intact moths hear at threshold.

  3. Tympanal mechanics and neural responses in the ears of a noctuid moth.

    PubMed

    ter Hofstede, Hannah M; Goerlitz, Holger R; Montealegre-Z, Fernando; Robert, Daniel; Holderied, Marc W

    2011-12-01

    Ears evolved in many groups of moths to detect the echolocation calls of predatory bats. Although the neurophysiology of bat detection has been intensively studied in moths for decades, the relationship between sound-induced movement of the noctuid tympanic membrane and action potentials in the auditory sensory cells (A1 and A2) has received little attention. Using laser Doppler vibrometry, we measured the velocity and displacement of the tympanum in response to pure tone pulses for moths that were intact or prepared for neural recording. When recording from the auditory nerve, the displacement of the tympanum at the neural threshold remained constant across frequencies, whereas velocity varied with frequency. This suggests that the key biophysical parameter for triggering action potentials in the sensory cells of noctuid moths is tympanum displacement, not velocity. The validity of studies on the neurophysiology of moth hearing rests on the assumption that the dissection and recording procedures do not affect the biomechanics of the ear. There were no consistent differences in tympanal velocity or displacement when moths were intact or prepared for neural recordings for sound levels close to neural threshold, indicating that this and other neurophysiological studies provide good estimates of what intact moths hear at threshold.

  4. Early permanent disappearance of abnormal muscle response during microvascular decompression for hemifacial spasm: a retrospective clinical study.

    PubMed

    Jiang, Chengrong; Xu, Wu; Dai, Yuxiang; Lu, Tianyu; Jin, Wei; Liang, Weibang

    2016-12-15

    The objective of this study is to explore the cause of early abnormal muscle response (AMR) disappearance during microvascular decompression for hemifacial spasm and the clinical outcomes of these patients. Three hundred seventy-two patients received microvascular decompression (MVD) under intraoperative electrophysiological monitoring in Nanjing Drum Tower Hospital in 2014; the characteristic AMR of HFS was observed in 359 patients during the operation. And the 359 patients were divided into two groups based on whether AMR had remained before the beginning of the decompression procedure for offending vessels. Thirty-three patients who showed a permanent disappearance of AMR before the beginning of decompression were regarded as group I. Dural opening and the succeeding CSF drainage produced a permanent disappearance of AMR in 13. During the dissection of lateral cerebellomedullary cistern, a permanent disappearance of AMR was found in 20 patients. Thirty-two patients were cured immediately; delayed resolution (7 days after surgery) was found in one patient. No complications were observed and no recurrence was found during the follow-up period in the 33 patients. In the other 326 patients (group II), AMR disappeared temporarily before the beginning of the decompression procedure for offending vessels in 42 patients. After decompression, AMR disappeared completely in 305 patients. Two hundred sixty-seven patients were cured immediately and 57 patients got a delayed resolution (2 days to 45 weeks after surgery). The two left did not get a complete abolition of spasm. Three cases of hearing loss, one hoarseness, and nine delayed facial paralysis were observed. The reason of early abnormal muscle response disappearance may be that the degree of neurovascular compression was not serious; these patients were more likely to get an immediate cure. Continuous intraoperative electrophysiological monitoring of AMR is necessary.

  5. Differential Neural Responses Underlying the Inhibition of the Startle Response by Pre-Pulses or Gaps in Mice

    PubMed Central

    Moreno-Paublete, Rocio; Canlon, Barbara; Cederroth, Christopher R.

    2017-01-01

    Gap pre-pulse inhibition of the acoustic startle (GPIAS) is a behavioral paradigm used for inferring the presence of tinnitus in animal models as well as humans. In contrast to pre-pulse inhibition (PPI), the neural circuitry controlling GPIAS is poorly understood. To increase our knowledge on GPIAS, a comparative study with PPI was performed in mice combining these behavioral tests and c-Fos activity mapping in brain areas involved in the inhibition of the acoustic startle reflex (ASR). Both pre-pulses and gaps efficiently inhibited the ASR and abolished the induction of c-Fos in the pontine reticular nucleus. Differential c-Fos activation was found between PPI and GPIAS in the forebrain whereby PPI activated the lateral globus pallidus and GPIAS activated the primary auditory cortex. Thus, different neural maps are regulating the inhibition of the startle response by pre-pulses or gaps. To further investigate this differential response to PPI and GPIAS, we pharmacologically disrupted PPI and GPIAS with D-amphetamine or Dizocilpine (MK-801) to target dopamine efflux and to block NMDA receptors, respectively. Both D-amp and MK-801 efficiently decreased PPI and GPIAS. We administered Baclofen, an agonist GABAB receptor, but failed to detect any robust rescue of the effects of D-amp and MK-801 suggesting that PPI and GPIAS are GABAB-independent. These novel findings demonstrate that the inhibition of the ASR by pre-pulses or gaps is orchestrated by different neural pathways. PMID:28239338

  6. Differential Neural Responses Underlying the Inhibition of the Startle Response by Pre-Pulses or Gaps in Mice.

    PubMed

    Moreno-Paublete, Rocio; Canlon, Barbara; Cederroth, Christopher R

    2017-01-01

    Gap pre-pulse inhibition of the acoustic startle (GPIAS) is a behavioral paradigm used for inferring the presence of tinnitus in animal models as well as humans. In contrast to pre-pulse inhibition (PPI), the neural circuitry controlling GPIAS is poorly understood. To increase our knowledge on GPIAS, a comparative study with PPI was performed in mice combining these behavioral tests and c-Fos activity mapping in brain areas involved in the inhibition of the acoustic startle reflex (ASR). Both pre-pulses and gaps efficiently inhibited the ASR and abolished the induction of c-Fos in the pontine reticular nucleus. Differential c-Fos activation was found between PPI and GPIAS in the forebrain whereby PPI activated the lateral globus pallidus and GPIAS activated the primary auditory cortex. Thus, different neural maps are regulating the inhibition of the startle response by pre-pulses or gaps. To further investigate this differential response to PPI and GPIAS, we pharmacologically disrupted PPI and GPIAS with D-amphetamine or Dizocilpine (MK-801) to target dopamine efflux and to block NMDA receptors, respectively. Both D-amp and MK-801 efficiently decreased PPI and GPIAS. We administered Baclofen, an agonist GABAB receptor, but failed to detect any robust rescue of the effects of D-amp and MK-801 suggesting that PPI and GPIAS are GABAB-independent. These novel findings demonstrate that the inhibition of the ASR by pre-pulses or gaps is orchestrated by different neural pathways.

  7. Abnormal N400 Responses But Intact Differential Hemispheric Processing of Ambiguity in Schizophrenia.

    PubMed

    Salisbury, Dean F

    2010-05-01

    Disordered thinking in schizophrenia may be a consequence of the selection of conceptual associates of dominant meanings of ambiguous words despite contextual information suggesting subordinate meanings are more appropriate. Previous work using short sentences showed a large N400 event-related potential to subordinate meaning associates and a behavioral semantic bias, but results were variable. The current experiment used word pairs to simplify the procedure and to less tax memory maintenance. Furthermore, hemispheric responses were compared, as evidence suggests the left hemisphere may select dominant meanings, while the right hemisphere may keep all possible meanings active. Subjects indicated whether two words (CUE, TARGET) were related. The CUE, presented for 1 second, could be an ambiguous or an unambiguous noun, and the TARGET, presented 1.25 seconds after the onset of the CUE, was a dominant or subordinate associate, or a related or an unrelated word, respectively. The N400-effect was calculated from difference waveforms over 400-600 msec. Groups (23 schizophrenia, 25 matched controls) showed significantly different N400-effects to the words (group x word, p =.04). Controls showed a graded response, with dominant < subordinate < unrelated. Schizophrenia patients showed the largest N400-effect to subordinate associates, with less activity to dominant meaning associates and unrelated words. Both groups showed a right hemisphere distribution to unrelated words and substantial left hemisphere activation to subordinate associates (word x hemisphere, p <.001). These data support a semantic bias in schizophrenia. They also demonstrate a special role of the right hemisphere in maintaining broad homograph meaning hierarchies. This hemispheric specialization appears to be intact in schizophrenia.

  8. Normal and abnormal face selectivity of the M170 response in developmental prosopagnosics.

    PubMed

    Harris, Alison M; Duchaine, Bradley C; Nakayama, Ken

    2005-01-01

    Developmental prosopagnosia is a lifelong impairment in face recognition despite normal low-level visual processing. Here we used magnetoencephalography (MEG) to examine the M170 response, a component occurring approximately 170 ms after stimulus onset, in a group of five developmental prosopagnosics. In normal subjects, the M170 is "face-selective", with a consistently higher amplitude to faces than to a wide variety of other visual stimulus categories; the N170, a component recorded using event-related potentials (ERP) and thought to be analogous to the M170, also shows this "face selectivity". Two previous ERP studies with developmental prosopagnosics have found attenuation or absence of face selectivity in the N170 response of these subjects [Bentin, S., Deouell, L. Y., and Soroker, N. (1999). Selective visual streaming in face recognition: Evidence from developmental prosopagnosia. Neuroreport, 10, 823-827; Kress, T., and Daum, I. (2003). Event-related potentials reflect impaired face recognition in patients with congenital prosopagnosia. Neuroscience Letters, 352, 133-136]. Three of our developmental prosopagnosic group showed this non-selective pattern at the M170 while the remaining two prosopagnosics were indistinguishable from normal controls. Thus, impaired face recognition is not necessarily correlated with an absence of the "face-selective" M170. Furthermore, ERP recordings collected simultaneously in the two developmental prosopagnosics with seemingly selective M170s also showed N170s within the same normal selective range, demonstrating that the face-selective signals found with MEG are not due to differences between MEG and ERP. While the presence of face selectivity at these neurophysiological markers is insufficient for predicting normal behavioral performance with faces, it could help to distinguish different classes of face recognition deficits.

  9. Neural responsivity during soft drink intake, anticipation, and advertisement exposure in habitually consuming youth

    PubMed Central

    Burger, Kyle S.; Stice, Eric

    2014-01-01

    OBJECTIVE Although soft drinks are heavily advertised, widely consumed, and have been associated with obesity, little is understood regarding neural responsivity to soft drink intake, anticipated intake, and advertisements. METHODS Functional MRI was used to assess examine neural response to carbonated soft drink intake, anticipated intake and advertisement exposure as well as milkshake intake in 27 adolescents that varied on soft drink consumer status. RESULTS Intake and anticipated intake of carbonated Coke® activated regions implicated in gustatory, oral somatosensory, and reward processing, yet high-fat/sugar milkshake intake elicited greater activation in these regions versus Coke intake. Advertisements highlighting the Coke product vs. non-food control advertisements, but not the Coke logo, activated gustatory and visual brain regions. Habitual Coke consumers vs. non-consumers showed greater posterior cingulate responsivity to Coke logo ads, suggesting that the logo is a conditioned cue. Coke consumers exhibited less ventrolateral prefrontal cortex responsivity during anticipated Coke intake relative to non-consumers. CONCLUSIONS Results indicate that soft drinks activate reward and gustatory regions, but are less potent in activating these regions than high-fat/sugar beverages, and imply that habitual soft drink intake promotes hyper-responsivity of regions encoding salience/attention toward brand specific cues and hypo-responsivity of inhibitory regions while anticipating intake. PMID:23836764

  10. Transgenic sickle cell trait mice do not exhibit abnormal thermoregulatory and stress responses to heat shock exposure.

    PubMed

    Chen, Yifan; Islam, Aminul

    2016-07-01

    There remains controversy over whether individuals with sickle cell trait (SCT) are vulnerable to health risks during physical activity in high temperatures. We examined thermoregulatory and stress-related responses to heat exposure in SCT and wild-type (WT) mice. No significant differences in core temperature (Tc) were observed between SCT and WT mice during heat exposure. There was no correlation between peak Tc during heat exposure and levels of hemoglobin S in SCT mice. Basal levels of circulating inflammatory and stress-related markers were not significantly different between SCT and WT mice. Although heat exposure caused significant increases in plasma interleukins 1β and 6, and 8-isoprostane in SCT and WT mice, no differences were found between SCT and WT mice with similar thermal response profiles during heat exposure. SCT mice had significantly higher expression of heat shock protein 72 in heart, liver and gastrocnemius muscle than WT mice under control and post-heat conditions. In conclusion, there is neither thermoregulatory dysfunction nor abnormal stress-related response in SCT mice exposed to moderate heat. The hemoglobin variant in mice is associated with altered tissue stress protein homeostasis.

  11. Racial bias in neural response to others' pain is reduced with other-race contact.

    PubMed

    Cao, Yuan; Contreras-Huerta, Luis Sebastian; McFadyen, Jessica; Cunnington, Ross

    2015-09-01

    Observing the pain of others has been shown to elicit greater activation in sensory and emotional areas of the brain suggested to represent a neural marker of empathy. This modulation of brain responses to others' pain is dependent on the race of the observed person, such that observing own-race people in pain is associated with greater activity in the anterior cingulate and bilateral insula cortices compared to other-race people. Importantly, it is not known how this racial bias to pain in other-race individuals might change over time in new immigrants or might depend on the level and quality of contact with people of the other-race. We investigated these issues by recruiting Chinese students who had first arrived in Australia within the past 6 months to 5 years and assessing their level of contact with other races across different social contexts using comprehensive rating scales. During fMRI, participants observed videos of own-race/other-race individuals, as well as own-group/other-group individuals, receiving painful or non-painful touch. The typical racial bias in neural responses to observed pain was evident, whereby activation in the anterior cingulate cortex (ACC) was greater for pain in own-race compared to other-race people. Crucially, activation in the anterior cingulate to pain in other races increased significantly with the level of contact participants reported with people of the other race. Importantly, this correlation did not depend on the closeness of contact or personal relationships, but simply on the overall level of experience with people of the other race in their every-day environment. Racial bias in neural responses to others' pain, as a neural marker of empathy, therefore changes with experience in new immigrants at least within 5 years of arrival in the new society and, crucially, depends on the level of contact with people of the other race in every-day life contexts.

  12. Abnormal humoral immune response to mucosal antigenic stimulation in patients with lung cancer.

    PubMed

    Michils, A; Yernault, J C; Noel, E; Gossart, B; Servais, G; Duchateau, J

    1992-05-01

    Previous studies have suggested an inverse relationship between atopy and cancer of mucosal surfaces. Atopy is classically assessed by detecting specific immunoglobulin E (IgE) antibodies against inhalant allergens. However, Platts-Mills recently proposed that atopy is the ability of an organism to recognize and to respond to limited doses of allergens presented at the mucosal level by producing not only IgE, but also immunoglobulin A and immunoglobulin G (IgG) antibodies. The authors compared the prevalence of atopy in 103 patients with lung cancer (a model of mucosal cancer), 51 patients with chronic obstructive pulmonary disease matched for age, sex, and smoking habits with patients with lung cancer, and 102 healthy control subjects. The authors investigated whether the IgG response to antigens presented at the mucosal level, exacerbated in atopic subjects, might inversely be decreased in patients with lung cancer. Serum IgE antibodies against five common inhalant allergens (Dermatophagoides pteronyssinus [Der p1], Aspergillus fumigatus, grass pollen, and cat and dog danders) were detected through a radioallergosorbent test assay. Serum IgG antibodies against allergens naturally presented at the mucosal level (respiratory mucosa with Der p1 and digestive mucosa with betalactoglobulin [BLG] and soya proteins [SP]) were measured through a solid phase enzyme-linked immunosorbent assay test. Atopic status was assessed in 19 patients (18.4%) with lung cancer, 9 patients (17.6%) with chronic obstructive pulmonary disease (COPD), and 18 healthy control subjects (17.6%). Distributions of specific IgG levels were represented on frequency histograms after natural logarithmic transformation and showed reduced levels of anti-Der p1 and anti-BLG IgG in the cancer population compared with the control populations but similar levels of anti-SP IgG. Influence of sex, age, smoking habits, histologic type of cancer, and its extent could be excluded. The authors' results show no

  13. Materials approaches for modulating neural tissue responses to implanted microelectrodes through mechanical and biochemical means

    PubMed Central

    Sommakia, Salah; Lee, Heui C.; Gaire, Janak; Otto, Kevin J.

    2014-01-01

    Implantable intracortical microelectrodes face an uphill struggle for widespread clinical use. Their potential for treating a wide range of traumatic and degenerative neural disease is hampered by their unreliability in chronic settings. A major factor in this decline in chronic performance is a reactive response of brain tissue, which aims to isolate the implanted device from the rest of the healthy tissue. In this review we present a discussion of materials approaches aimed at modulating the reactive tissue response through mechanical and biochemical means. Benefits and challenges associated with these approaches are analyzed, and the importance of multimodal solutions tested in emerging animal models are presented. PMID:25530703

  14. Abnormal pituitary-gonadal axis may be responsible for rat decreased testicular function under simulated microgravity

    NASA Astrophysics Data System (ADS)

    Zhou, Yi; Tan, Xin; Zhu, Bao-an; Qi, Meng-di; Ding, Su-ling

    Space flight and simulated microgravity lead to suppression of mammalian spermatogenesis and decreased plasma testosterone level. In order to explain the mechanism behind the depression, we used rat tail-suspended model to simulate weightless conditions. To prevent cryptorchidism caused by tail-suspension, some experimental animals received inguinal canal ligation. The results showed that mass of testis decreased significantly and seminiferous tubules became atrophied in rats after tail-suspension. The levels of plasma testosterone (T), luteinizing hormone (LH), and follicle-stimulating hormone (FSH) in tail-suspended rats with or without inguinal canal ligation decreased significantly compared with controls, and an increased level of plasma estradiol (E) was revealed in tail-suspended rats. The results indicate that besides the direct influence of fluid shift upon testis under short-term simulated microgravity, the pituitary function is also disturbed as a result of either immobilization stress or weight loss during tail-suspension treatment, which is responsible to some extent for the decreased testosterone secretion level and the atrophia of testis. The conversion of testosterone into E under simulated microgravity is another possible cause for the decline of plasma testosterone.

  15. Abnormal Glycosphingolipid Mannosylation Triggers Salicylic Acid–Mediated Responses in Arabidopsis[W][OA

    PubMed Central

    Mortimer, Jenny C.; Yu, Xiaolan; Albrecht, Sandra; Sicilia, Francesca; Huichalaf, Mariela; Ampuero, Diego; Michaelson, Louise V.; Murphy, Alex M.; Matsunaga, Toshiro; Kurz, Samantha; Stephens, Elaine; Baldwin, Timothy C.; Ishii, Tadashi; Napier, Johnathan A.; Weber, Andreas P.M.; Handford, Michael G.; Dupree, Paul

    2013-01-01

    The Arabidopsis thaliana protein GOLGI-LOCALIZED NUCLEOTIDE SUGAR TRANSPORTER (GONST1) has been previously identified as a GDP-d-mannose transporter. It has been hypothesized that GONST1 provides precursors for the synthesis of cell wall polysaccharides, such as glucomannan. Here, we show that in vitro GONST1 can transport all four plant GDP-sugars. However, gonst1 mutants have no reduction in glucomannan quantity and show no detectable alterations in other cell wall polysaccharides. By contrast, we show that a class of glycosylated sphingolipids (glycosylinositol phosphoceramides [GIPCs]) contains Man and that this mannosylation is affected in gonst1. GONST1 therefore is a Golgi GDP-sugar transporter that specifically supplies GDP-Man to the Golgi lumen for GIPC synthesis. gonst1 plants have a dwarfed phenotype and a constitutive hypersensitive response with elevated salicylic acid levels. This suggests an unexpected role for GIPC sugar decorations in sphingolipid function and plant defense signaling. Additionally, we discuss these data in the context of substrate channeling within the Golgi. PMID:23695979

  16. Transient and sustained neural responses to death-related linguistic cues.

    PubMed

    Shi, Zhenhao; Han, Shihui

    2013-06-01

    Recent research showed that perception of death-related vs death-unrelated linguistic cues produced increased frontoparietal activity but decreased insular activity. This study investigated (i) whether the increased frontoparietal and decreased insular activities are, respectively, associated with transient trial-specific processes of death-related linguistic cues and sustained death-related thought during death-relevance judgments on linguistic cues and (ii) whether the neural activity underlying death-related thought can predict individuals' dispositional death anxiety. Participants were presented with death-related/unrelated words, life-related/unrelated words, and negative-valence/neutral words in separate sessions. Participants were scanned using functional magnetic resonance imaging while performing death-relevance, life-relevance, and valence judgments on the words, respectively. The contrast of death-related vs death-unrelated words during death-relevance judgments revealed transient increased activity in the left inferior parietal lobule, the right frontal eye field, and the right superior parietal lobule. The contrast of death-relevance judgments vs life-relevance/valence judgments showed decreased activity in the bilateral insula. The sustained insular activity was correlated with dispositional death anxiety, but only in those with weak transient frontoparietal responses to death-related words. Our results dissociate the transient and sustained neural responses to death-related linguistic cues and suggest that the combination of the transient and sustained neural activities can predict dispositional death anxiety.

  17. Viscoelastic response of neural cells governed by the deposition of amyloid-β peptides (Aβ)

    NASA Astrophysics Data System (ADS)

    Gong, Ze; You, Ran; Chang, Raymond Chuen-Chung; Lin, Yuan

    2016-06-01

    Because of its intimate relation with Alzheimer's disease (AD), the question of how amyloid-β peptide (Aβ) deposition alters the membrane and cytoskeltal structure of neural cells and eventually their mechanical response has received great attention. In this study, the viscoelastic properties of primary neurons subjected to various Aβ treatments were systematically characterized using atomic force microrheology. It was found that both the storage ( G ') and loss ( G ″) moduli of neural cells are rate-dependent and grow by orders of magnitude as the driving frequency ω varies from 1 to 100 Hz. However, a much stronger frequency dependence was observed in the loss moduli (with a scaling exponent of ˜0.96) than that in G ' ( ˜ ω 0.2 ). Furthermore, both cell moduli increase gradually within the first 6 h of Aβ treatment before steady-state values are reached, with a higher dosage of Aβ leading to larger changes in cell properties. Interestingly, we showed that the measured neuron response can be well-explained by a power law structural damping model. Findings here establish a quantitative link between Aβ accumulation and the physical characteristics of neural cells and hence could provide new insights into how disorders like AD affect the progression of different neurological processes from a mechanics point of view.

  18. The Human Neural Alpha Response to Speech is a Proxy of Attentional Control.

    PubMed

    Wöstmann, Malte; Lim, Sung-Joo; Obleser, Jonas

    2017-03-18

    Human alpha (~10 Hz) oscillatory power is a prominent neural marker of cognitive effort. When listeners attempt to process and retain acoustically degraded speech, alpha power enhances. It is unclear whether these alpha modulations reflect the degree of acoustic degradation per se or the degradation-driven demand to a listener's attentional control. Using an irrelevant-speech paradigm and measuring the electroencephalogram (EEG), the current experiment demonstrates that the neural alpha response to speech is a surprisingly clear proxy of top-down control, entirely driven by the listening goals of attending versus ignoring degraded speech. While (n = 23) listeners retained the serial order of 9 to-be-recalled digits, one to-be-ignored sentence was presented. Distractibility of the to-be-ignored sentence parametrically varied in acoustic detail (noise-vocoding), with more acoustic detail of distracting speech increasingly disrupting listeners' serial memory recall. Where previous studies had observed decreases in parietal and auditory alpha power with more acoustic detail (of target speech), alpha power here showed the opposite pattern and increased with more acoustic detail in the speech distractor. In sum, the neural alpha response reflects almost exclusively a listener's goal, which is decisive for whether more acoustic detail facilitates comprehension (of attended speech) or enhances distraction (of ignored speech).

  19. Sex differences in behavioural and neural responsiveness to mate calls in a parrot

    PubMed Central

    Eda-Fujiwara, Hiroko; Satoh, Ryohei; Hata, Yuka; Yamasaki, Marika; Watanabe, Aiko; Zandbergen, Matthijs A.; Okamoto, Yasuharu; Miyamoto, Takenori; Bolhuis, Johan J.

    2016-01-01

    Vocalisation in songbirds and parrots has become a prominent model system for speech and language in humans. We investigated possible sex differences in behavioural and neural responsiveness to mate calls in the budgerigar, a vocally-learning parrot. Males and females were paired for 5 weeks and then separated, after which we measured vocal responsiveness to playback calls (a call of their mate versus a call of an unfamiliar conspecific). Both sexes learned to recognise mate calls during the pairing period. In males, but not females, mate calls evoked significantly fewer vocal responses than unfamiliar calls at one month after separation. Furthermore, in females, there was significantly greater molecular neuronal activation in response to mate calls compared to silence in the caudomedial mesopallium (CMM), a higher-order auditory region, in both brain hemispheres. In males, we found right-sided dominance of molecular neuronal activation in response to mate calls in the CMM. This is the first evidence suggesting sex differences in functional asymmetry of brain regions related to recognition of learned vocalisation in birds. Thus, sex differences related to recognition of learned vocalisations may be found at the behavioural and neural levels in avian vocal learners as it is in humans. PMID:26725947

  20. A Neural Mechanism for Nonconscious Activation of Conditioned Placebo and Nocebo Responses.

    PubMed

    Jensen, Karin B; Kaptchuk, Ted J; Chen, Xiaoyan; Kirsch, Irving; Ingvar, Martin; Gollub, Randy L; Kong, Jian

    2015-10-01

    Fundamental aspects of human behavior operate outside of conscious awareness. Yet, theories of conditioned responses in humans, such as placebo and nocebo effects on pain, have a strong emphasis on conscious recognition of contextual cues that trigger the response. Here, we investigated the neural pathways involved in nonconscious activation of conditioned pain responses, using functional magnetic resonance imaging in healthy participants. Nonconscious compared with conscious activation of conditioned placebo analgesia was associated with increased activation of the orbitofrontal cortex, a structure with direct connections to affective brain regions and basic reward processing. During nonconscious nocebo, there was increased activation of the thalamus, amygdala, and hippocampus. In contrast to previous assumptions about conditioning in humans, our results show that conditioned pain responses can be elicited independently of conscious awareness and our results suggest a hierarchical activation of neural pathways for nonconscious and conscious conditioned responses. Demonstrating that the human brain has a nonconscious mechanism for responding to conditioned cues has major implications for the role of associative learning in behavioral medicine and psychiatry. Our results may also open up for novel approaches to translational animal-to-human research since human consciousness and animal cognition is an inherent paradox in all behavioral science.

  1. Sex differences in behavioural and neural responsiveness to mate calls in a parrot.

    PubMed

    Eda-Fujiwara, Hiroko; Satoh, Ryohei; Hata, Yuka; Yamasaki, Marika; Watanabe, Aiko; Zandbergen, Matthijs A; Okamoto, Yasuharu; Miyamoto, Takenori; Bolhuis, Johan J

    2016-01-04

    Vocalisation in songbirds and parrots has become a prominent model system for speech and language in humans. We investigated possible sex differences in behavioural and neural responsiveness to mate calls in the budgerigar, a vocally-learning parrot. Males and females were paired for 5 weeks and then separated, after which we measured vocal responsiveness to playback calls (a call of their mate versus a call of an unfamiliar conspecific). Both sexes learned to recognise mate calls during the pairing period. In males, but not females, mate calls evoked significantly fewer vocal responses than unfamiliar calls at one month after separation. Furthermore, in females, there was significantly greater molecular neuronal activation in response to mate calls compared to silence in the caudomedial mesopallium (CMM), a higher-order auditory region, in both brain hemispheres. In males, we found right-sided dominance of molecular neuronal activation in response to mate calls in the CMM. This is the first evidence suggesting sex differences in functional asymmetry of brain regions related to recognition of learned vocalisation in birds. Thus, sex differences related to recognition of learned vocalisations may be found at the behavioural and neural levels in avian vocal learners as it is in humans.

  2. Insulin response dysregulation explains abnormal fat storage and increased risk of diabetes mellitus type 2 in Cohen Syndrome.

    PubMed

    Limoge, Floriane; Faivre, Laurence; Gautier, Thomas; Petit, Jean-Michel; Gautier, Elodie; Masson, David; Jego, Gaëtan; El Chehadeh-Djebbar, Salima; Marle, Nathalie; Carmignac, Virginie; Deckert, Valérie; Brindisi, Marie-Claude; Edery, Patrick; Ghoumid, Jamal; Blair, Edward; Lagrost, Laurent; Thauvin-Robinet, Christel; Duplomb, Laurence

    2015-12-01

    Cohen Syndrome (CS) is a rare autosomal recessive disorder, with defective glycosylation secondary to mutations in the VPS13B gene, which encodes a protein of the Golgi apparatus. Besides congenital neutropenia, retinopathy and intellectual deficiency, CS patients are faced with truncal obesity. Metabolism investigations showed abnormal glucose tolerance tests and low HDL values in some patients, and these could be risk factors for the development of diabetes mellitus and/or cardiovascular complications. To understand the mechanisms involved in CS fat storage, we used two models of adipogenesis differentiation: (i) SGBS pre-adipocytes with VPS13B invalidation thanks to siRNA delivery and (ii) CS primary fibroblasts. In both models, VPS13B invalidation led to accelerated differentiation into fat cells, which was confirmed by the earlier and increased expression of specific adipogenic genes, consequent to the increased response of cells to insulin stimulation. At the end of the differentiation protocol, these fat cells exhibited decreased AKT2 phosphorylation after insulin stimulation, which suggests insulin resistance. This study, in association with the in-depth analysis of the metabolic status of the patients, thus allowed us to recommend appropriate nutritional education to prevent the occurrence of diabetes mellitus and to put forward recommendations for the follow-up of CS patients, in particular with regard to the development of metabolic syndrome. We also suggest replacing the term obesity by abnormal fat distribution in CS, which should reduce the number of inappropriate diagnoses in patients who are referred only on the basis of intellectual deficiency associated with obesity.

  3. EMOTION REGULATION ABNORMALITIES IN SCHIZOPHRENIA: DIRECTED ATTENTION STRATEGIES FAIL TO DECREASE THE NEUROPHYSIOLOGICAL RESPONSE TO UNPLEASANT STIMULI

    PubMed Central

    Strauss, Gregory P.; Kappenman, Emily S.; Culbreth, Adam J.; Catalano, Lauren T.; Ossenfort, Kathryn L.; Lee, Bern G.; Gold, James M.

    2015-01-01

    Previous research provides evidence that individuals with schizophrenia (SZ) have emotion regulation abnormalities, particularly when attempting to use reappraisal to decrease negative emotion. The current study extended this literature by examining the effectiveness of a different form of emotion regulation, directed attention, which has been shown to be effective at reducing negative emotion in healthy individuals. Participants included outpatients with SZ (n = 28) and healthy controls (CN: n = 25), who viewed unpleasant and neutral images during separate event-related potential (ERP) and eye-movement tasks. Trials included both passive viewing and directed attention segments. During directed attention, gaze was directed toward highly arousing aspects of an unpleasant image, less arousing aspects of an unpleasant image, or a non-arousing aspect of a neutral image. The late positive potential (LPP) ERP component indexed emotion regulation success. Directing attention to non-arousing aspects of unpleasant images decreased the LPP in CN; however, SZ showed similar LPP amplitude when attention was directed toward more or less arousing aspects of unpleasant scenes. Eye tracking indicated that SZ were more likely than CN to attend to arousing portions of unpleasant scenes when attention was directed toward less arousing scene regions. Furthermore, pupilary data suggested that SZ patients failed to engage effortful cognitive processes needed to inhibit the prepotent response of attending to arousing aspects of unpleasant scenes when attention was directed toward non-arousing scene regions. Findings add to the growing literature indicating that individuals with SZ display emotion regulation abnormalities and provide novel evidence that dysfunctional emotion-attention interactions and generalized cognitive control deficits are associated with ineffective use of directed attention strategies to regulate negative emotion. PMID:25486078

  4. Lack of parvalbumin in mice leads to behavioral deficits relevant to all human autism core symptoms and related neural morphofunctional abnormalities

    PubMed Central

    Wöhr, M; Orduz, D; Gregory, P; Moreno, H; Khan, U; Vörckel, K J; Wolfer, D P; Welzl, H; Gall, D; Schiffmann, S N; Schwaller, B

    2015-01-01

    Gene mutations and gene copy number variants are associated with autism spectrum disorders (ASDs). Affected gene products are often part of signaling networks implicated in synapse formation and/or function leading to alterations in the excitation/inhibition (E/I) balance. Although the network of parvalbumin (PV)-expressing interneurons has gained particular attention in ASD, little is known on PV's putative role with respect to ASD. Genetic mouse models represent powerful translational tools for studying the role of genetic and neurobiological factors underlying ASD. Here, we report that PV knockout mice (PV−/−) display behavioral phenotypes with relevance to all three core symptoms present in human ASD patients: abnormal reciprocal social interactions, impairments in communication and repetitive and stereotyped patterns of behavior. PV-depleted mice also showed several signs of ASD-associated comorbidities, such as reduced pain sensitivity and startle responses yet increased seizure susceptibility, whereas no evidence for behavioral phenotypes with relevance to anxiety, depression and schizophrenia was obtained. Reduced social interactions and communication were also observed in heterozygous (PV+/−) mice characterized by lower PV expression levels, indicating that merely a decrease in PV levels might be sufficient to elicit core ASD-like deficits. Structural magnetic resonance imaging measurements in PV−/− and PV+/− mice further revealed ASD-associated developmental neuroanatomical changes, including transient cortical hypertrophy and cerebellar hypoplasia. Electrophysiological experiments finally demonstrated that the E/I balance in these mice is altered by modification of both inhibitory and excitatory synaptic transmission. On the basis of the reported changes in PV expression patterns in several, mostly genetic rodent models of ASD, we propose that in these models downregulation of PV might represent one of the points of convergence, thus

  5. Neural Network Model Of The PXIE RFQ Cooling System and Resonant Frequency Response

    SciTech Connect

    Edelen, Auralee; Biedron, Sandra; Bowring, Daniel; Chase, Brian; Edelen, Jonathan; Milton, Stephen; Steimel, Jim

    2016-06-01

    As part of the PIP-II Injector Experiment (PXIE) accel-erator, a four-vane radio frequency quadrupole (RFQ) accelerates a 30-keV, 1-mA to 10-mA H' ion beam to 2.1 MeV. It is designed to operate at a frequency of 162.5 MHz with arbitrary duty factor, including continuous wave (CW) mode. The resonant frequency is controlled solely by a water-cooling system. We present an initial neural network model of the RFQ frequency response to changes in the cooling system and RF power conditions during pulsed operation. A neural network model will be used in a model predictive control scheme to regulate the resonant frequency of the RFQ.

  6. Input Response of Neural Network Model with Lognormally Distributed Synaptic Weights

    NASA Astrophysics Data System (ADS)

    Nagano, Yoshihiro; Karakida, Ryo; Watanabe, Norifumi; Aoyama, Atsushi; Okada, Masato

    2016-07-01

    Neural assemblies in the cortical microcircuit can sustain irregular spiking activity without external inputs. On the other hand, neurons exhibit rich evoked activities driven by sensory stimulus, and both activities are reported to contribute to cognitive functions. We studied the external input response of the neural network model with lognormally distributed synaptic weights. We show that the model can achieve irregular spontaneous activity and population oscillation depending on the presence of external input. The firing rate distribution was maintained for the external input, and the order of firing rates in evoked activity reflected that in spontaneous activity. Moreover, there were bistable regions in the inhibitory input parameter space. The bimodal membrane potential distribution, which is a characteristic feature of the up-down state, was obtained under such conditions. From these results, we can conclude that the model displays various evoked activities due to the external input and is biologically plausible.

  7. Studying the glial cell response to biomaterials and surface topography for improving the neural electrode interface

    NASA Astrophysics Data System (ADS)

    Ereifej, Evon S.

    Neural electrode devices hold great promise to help people with the restoration of lost functions, however, research is lacking in the biomaterial design of a stable, long-term device. Current devices lack long term functionality, most have been found unable to record neural activity within weeks after implantation due to the development of glial scar tissue (Polikov et al., 2006; Zhong and Bellamkonda, 2008). The long-term effect of chronically implanted electrodes is the formation of a glial scar made up of reactive astrocytes and the matrix proteins they generate (Polikov et al., 2005; Seil and Webster, 2008). Scarring is initiated when a device is inserted into brain tissue and is associated with an inflammatory response. Activated astrocytes are hypertrophic, hyperplastic, have an upregulation of intermediate filaments GFAP and vimentin expression, and filament formation (Buffo et al., 2010; Gervasi et al., 2008). Current approaches towards inhibiting the initiation of glial scarring range from altering the geometry, roughness, size, shape and materials of the device (Grill et al., 2009; Kotov et al., 2009; Kotzar et al., 2002; Szarowski et al., 2003). Literature has shown that surface topography modifications can alter cell alignment, adhesion, proliferation, migration, and gene expression (Agnew et al., 1983; Cogan et al., 2005; Cogan et al., 2006; Merrill et al., 2005). Thus, the goals of the presented work are to study the cellular response to biomaterials used in neural electrode fabrication and assess surface topography effects on minimizing astrogliosis. Initially, to examine astrocyte response to various materials used in neural electrode fabrication, astrocytes were cultured on platinum, silicon, PMMA, and SU-8 surfaces, with polystyrene as the control surface. Cell proliferation, viability, morphology and gene expression was measured for seven days in vitro. Results determined the cellular characteristics, reactions and growth rates of astrocytes

  8. Temperament and Parenting Styles in Early Childhood Differentially Influence Neural Response to Peer Evaluation in Adolescence

    PubMed Central

    Guyer, Amanda E.; Jarcho, Johanna M.; Pérez-Edgar, Koraly; Degnan, Kathryn A.; Pine, Daniel S.; Fox, Nathan A.; Nelson, Eric E.

    2015-01-01

    Behavioral inhibition (BI) is a temperament characterized by social reticence and withdrawal from unfamiliar or novel contexts and conveys risk for social anxiety disorder. Developmental outcomes associated with this temperament can be influenced by children’s caregiving context. The convergence of a child’s temperamental disposition and rearing environment is ultimately expressed at both the behavioral and neural levels in emotional and cognitive response patterns to social challenges. The present study used functional neuroimaging to assess the moderating effects of different parenting styles on neural response to peer rejection in two groups of adolescents characterized by their early childhood temperament (Mage = 17.89 years, N= 39, 17 males, 22 females; 18 with BI; 21 without BI). The moderating effects of authoritarian and authoritative parenting styles were examined in three brain regions linked with social anxiety: ventrolateral prefrontal cortex (vlPFC), striatum, and amygdala. In youth characterized with BI in childhood, but not in those without BI, diminished responses to peer rejection in vlPFC were associated with higher levels of authoritarian parenting. In contrast, all youth showed decreased caudate response to peer rejection at higher levels of authoritative parenting. These findings indicate that BI in early life relates to greater neurobiological sensitivity to variance in parenting styles, particularly harsh parenting, in late adolescence. These results are discussed in relation to biopsychosocial models of development. PMID:25588884

  9. Quantitative Nucleotide Level Analysis of Regulation of Translation in Response to Depolarization of Cultured Neural Cells

    PubMed Central

    Dalal, Jasbir S.; Yang, Chengran; Sapkota, Darshan; Lake, Allison M.; O'Brien, David R.; Dougherty, Joseph D.

    2017-01-01

    Studies on regulation of gene expression have contributed substantially to understanding mechanisms for the long-term activity-dependent alterations in neural connectivity that are thought to mediate learning and memory. Most of these studies, however, have focused on the regulation of mRNA transcription. Here, we utilized high-throughput sequencing coupled with ribosome footprinting to globally characterize the regulation of translation in primary mixed neuronal-glial cultures in response to sustained depolarization. We identified substantial and complex regulation of translation, with many transcripts demonstrating changes in ribosomal occupancy independent of transcriptional changes. We also examined sequence-based mechanisms that might regulate changes in translation in response to depolarization. We found that these are partially mediated by features in the mRNA sequence—notably upstream open reading frames and secondary structure in the 5′ untranslated region—both of which predict downregulation in response to depolarization. Translationally regulated transcripts are also more likely to be targets of FMRP and include genes implicated in autism in humans. Our findings support the idea that control of mRNA translation plays an important role in response to neural activity across the genome. PMID:28190998

  10. Temperament and Parenting Styles in Early Childhood Differentially Influence Neural Response to Peer Evaluation in Adolescence.

    PubMed

    Guyer, Amanda E; Jarcho, Johanna M; Pérez-Edgar, Koraly; Degnan, Kathryn A; Pine, Daniel S; Fox, Nathan A; Nelson, Eric E

    2015-07-01

    Behavioral inhibition (BI) is a temperament characterized by social reticence and withdrawal from unfamiliar or novel contexts and conveys risk for social anxiety disorder. Developmental outcomes associated with this temperament can be influenced by children's caregiving context. The convergence of a child's temperamental disposition and rearing environment is ultimately expressed at both the behavioral and neural levels in emotional and cognitive response patterns to social challenges. The present study used functional neuroimaging to assess the moderating effects of different parenting styles on neural response to peer rejection in two groups of adolescents characterized by their early childhood temperament (M(age) = 17.89 years, N = 39, 17 males, 22 females; 18 with BI; 21 without BI). The moderating effects of authoritarian and authoritative parenting styles were examined in three brain regions linked with social anxiety: ventrolateral prefrontal cortex (vlPFC), striatum, and amygdala. In youth characterized with BI in childhood, but not in those without BI, diminished responses to peer rejection in vlPFC were associated with higher levels of authoritarian parenting. In contrast, all youth showed decreased caudate response to peer rejection at higher levels of authoritative parenting. These findings indicate that BI in early life relates to greater neurobiological sensitivity to variance in parenting styles, particularly harsh parenting, in late adolescence. These results are discussed in relation to biopsychosocial models of development.

  11. Endotoxin "priming" potentiates lung vascular abnormalities in response to Escherichia coli hemolysin: an example of synergism between endo- and exotoxin

    PubMed Central

    1994-01-01

    The pore-forming hemolysin of Escherichia coli (HlyA), an important virulence factor in extraintestinal E. coli infections, causes thromboxane generation and related vasoconstriction in perfused rabbit lungs (Seeger, W., H. Walter, N. Suttorp, M. Muhly, and S. Bhakdi. 1989. J. Clin. Invest. 84:220). We investigated the influence of pulmonary vascular "priming" with endotoxin on the responsiveness of the lung to a low-dose HlyA challenge. Rabbit lungs were perfused with Krebs Henseleit buffer containing 0.1-100 ng/ml Salmonella abortus equii lipopolysaccharide (LPS) for 60-180 min. This treatment caused protracted release of tumor necrosis factor into the recirculating medium, but did not induce significant alterations of pulmonary hemodynamics and fluid balance. At a dose of 1 ng/ml, HlyA elicited only moderate thromboxane release (< 200 pg/ml) and pulmonary artery pressure increase (< or = 6 mmHg) in control lungs. Acceleration and potentiation of both the metabolic and vasoconstrictor response occurred in lungs primed with LPS. This priming effect displayed dose (threshold integral of 0.1-1 ng/ml LPS) and time dependencies (threshold integral of 60-90 min LPS incubation). Maximum thromboxane release and pulmonary artery pressure increase surpassed the responses to HlyA in nonprimed lungs by more than 15-fold. Cyclooxygenase inhibition and thromboxane-receptor antagonism blocked these effects. These data demonstrate that LPS priming synergizes with HlyA challenge to provoke vascular abnormalities that are possibly relevant to the pathogenesis of organ failure in severe local and systemic infections. PMID:7931076

  12. Variability of Neuronal Responses: Types and Functional Significance in Neuroplasticity and Neural Darwinism

    PubMed Central

    Chervyakov, Alexander V.; Sinitsyn, Dmitry O.; Piradov, Michael A.

    2016-01-01

    HIGHLIGHTS We suggest classifying variability of neuronal responses as follows: false (associated with a lack of knowledge about the influential factors), “genuine harmful” (noise), “genuine neutral” (synonyms, repeats), and “genuine useful” (the basis of neuroplasticity and learning).The genuine neutral variability is considered in terms of the phenomenon of degeneracy.Of particular importance is the genuine useful variability that is considered as a potential basis for neuroplasticity and learning. This type of variability is considered in terms of the neural Darwinism theory. In many cases, neural signals detected under the same external experimental conditions significantly change from trial to trial. The variability phenomenon, which complicates extraction of reproducible results and is ignored in many studies by averaging, has attracted attention of researchers in recent years. In this paper, we classify possible types of variability based on its functional significance and describe features of each type. We describe the key adaptive significance of variability at the neural network level and the degeneracy phenomenon that may be important for learning processes in connection with the principle of neuronal group selection. PMID:27932969

  13. Variability of Neuronal Responses: Types and Functional Significance in Neuroplasticity and Neural Darwinism.

    PubMed

    Chervyakov, Alexander V; Sinitsyn, Dmitry O; Piradov, Michael A

    2016-01-01

    HIGHLIGHTS We suggest classifying variability of neuronal responses as follows: false (associated with a lack of knowledge about the influential factors), "genuine harmful" (noise), "genuine neutral" (synonyms, repeats), and "genuine useful" (the basis of neuroplasticity and learning).The genuine neutral variability is considered in terms of the phenomenon of degeneracy.Of particular importance is the genuine useful variability that is considered as a potential basis for neuroplasticity and learning. This type of variability is considered in terms of the neural Darwinism theory. In many cases, neural signals detected under the same external experimental conditions significantly change from trial to trial. The variability phenomenon, which complicates extraction of reproducible results and is ignored in many studies by averaging, has attracted attention of researchers in recent years. In this paper, we classify possible types of variability based on its functional significance and describe features of each type. We describe the key adaptive significance of variability at the neural network level and the degeneracy phenomenon that may be important for learning processes in connection with the principle of neuronal group selection.

  14. Neural response to pictorial health warning labels can predict smoking behavioral change

    PubMed Central

    Riddle, Philip J.; Newman-Norlund, Roger D.; Baer, Jessica; Thrasher, James F.

    2016-01-01

    In order to improve our understanding of how pictorial health warning labels (HWLs) influence smoking behavior, we examined whether brain activity helps to explain smoking behavior above and beyond self-reported effectiveness of HWLs. We measured the neural response in the ventromedial prefrontal cortex (vmPFC) and the amygdala while adult smokers viewed HWLs. Two weeks later, participants’ self-reported smoking behavior and biomarkers of smoking behavior were reassessed. We compared multiple models predicting change in self-reported smoking behavior (cigarettes per day [CPD]) and change in a biomarkers of smoke exposure (expired carbon monoxide [CO]). Brain activity in the vmPFC and amygdala not only predicted changes in CO, but also accounted for outcome variance above and beyond self-report data. Neural data were most useful in predicting behavioral change as quantified by the objective biomarker (CO). This pattern of activity was significantly modulated by individuals’ intention to quit. The finding that both cognitive (vmPFC) and affective (amygdala) brain areas contributed to these models supports the idea that smokers respond to HWLs in a cognitive-affective manner. Based on our findings, researchers may wish to consider using neural data from both cognitive and affective networks when attempting to predict behavioral change in certain populations (e.g. cigarette smokers). PMID:27405615

  15. Less is not more: neural responses to missing and superfluous accents in context.

    PubMed

    Dimitrova, Diana V; Stowe, Laurie A; Redeker, Gisela; Hoeks, John C J

    2012-12-01

    Prosody, particularly accent, aids comprehension by drawing attention to important elements such as the information that answers a question. A study using ERP registration investigated how the brain deals with the interpretation of prosodic prominence. Sentences were embedded in short dialogues and contained accented elements that were congruous or incongruous with respect to a preceding question. In contrast to previous studies, no explicit prosodic judgment task was added. Robust effects of accentuation were evident in the form of an "accent positivity" (200-500 msec) for accented elements irrespective of their congruity. Our results show that incongruously accented elements, that is, superfluous accents, activate a specific set of neural systems that is inactive in case of incongruously unaccented elements, that is, missing accents. Superfluous accents triggered an early positivity around 100 msec poststimulus, followed by a right-lateralized negative effect (N400). This response suggests that redundant information is identified immediately and leads to the activation of a neural system that is associated with semantic processing (N400). No such effects were found when contextually expected accents were missing. In a later time window, both missing and superfluous accents triggered a late positivity on midline electrodes, presumably related to making sense of both kinds of mismatching stimuli. These results challenge previous findings of greater processing for missing accents and suggest that the natural processing of prosody involves a set of distinct, temporally organized neural systems.

  16. Parallel processing in an identified neural circuit: the Aplysia californica gill-withdrawal response model system.

    PubMed

    Leonard, Janet L; Edstrom, John P

    2004-02-01

    The response of the gill of Aplysia calfornica Cooper to weak to moderate tactile stimulation of the siphon, the gill-withdrawal response or GWR, has been an important model system for work aimed at understanding the relationship between neural plasticity and simple forms of non-associative and associative learning. Interest in the GWR has been based largely on the hypothesis that the response could be explained adequately by parallel monosynaptic reflex arcs between six parietovisceral ganglion (PVG) gill motor neurons (GMNs) and a cluster of sensory neurons termed the LE cluster. This hypothesis, the Kupfermann-Kandel model, made clear, falsifiable predictions that have stimulated experimental work for many years. Here, we review tests of three predictions of the Kupfermann-Kandel model: (1) that the GWR is a simple, reflexive behaviour graded with stimulus intensity; (2) that central nervous system (CNS) pathways are necessary and sufficient for the GWR; and (3) that activity in six identified GMNs is sufficient to account for the GWR. The available data suggest that (1) a variety of action patterns occur in the context of the GWR; (2) the PVG is not necessary and the diffuse peripheral nervous system (PNS) is sufficient to mediate these action patterns; and (3) the role of any individual GMN in the behaviour varies. Both the control of gill-withdrawal responses, and plasticity in these responses, are broadly distributed across both PNS and CNS pathways. The Kupfermann-Kandel model is inconsistent with the available data and therefore stands rejected. There is, no known causal connection or correlation between the observed plasticity at the identified synapses in this system and behavioural changes during non-associative and associative learning paradigms. Critical examination of these well-studied central pathways suggests that they represent a 'wetware' neural network, architecturally similar to the neural network models of the widely used 'Perceptron' and

  17. Preliminary evidence of sex differences in behavioral and neural responses to palatable food reward in rats.

    PubMed

    Sinclair, Elaine B; Hildebrandt, Britny A; Culbert, Kristen M; Klump, Kelly L; Sisk, Cheryl L

    2017-03-30

    The female bias in eating disorder prevalence is the largest in all of psychiatry. Binge eating on palatable food (PF) is a core, maladaptive symptom that cuts across all major types of eating disorders and can be studied via animal models. Using an individual differences rat model of binge eating that identifies binge eating prone (BEP) and binge eating resistant (BER) phenotypes, we previously showed that, compared with males, females consume more PF and are more likely to be classified as BEP. One potential explanation for this sex difference is that PF is inherently more rewarding to females, leading to higher rates of binge eating. Here we tested the hypothesis that females have more robust behavioral and neural responses to PF reward than males. Adult male (N=18) and female (N=17) Sprague-Dawley rats were exposed to the Conditioned Place Preference paradigm using PF as the unconditioned stimulus. Select males (N=9) and females (N=9) were video-recorded during three of the PF-paired conditioning sessions to score feeding behavior. Following CPP, 13 male and 12 female rats were exposed to PF just prior to sacrifice to induce expression of the neural activation marker Fos, and Fos expression was quantified in mesocorticolimbic, hypothalamic, and amygdalar circuits. In the CPP paradigm, females displayed a more robust shift in preference for the chamber paired with PF compared with males, and behavioral analyses revealed that average duration of individual feeding bouts during pairing sessions was longer in females than in males. Fos expression was significantly higher in females vs. males in select regions of the mesocorticolimbic reward circuit, with no sex differences in hypothalamic or amygdalar regions. These results provide initial evidence that PF may be more rewarding to females than to males, possibly due to heightened responsiveness of neural substrates that mediate the hedonic and motivational responses to PF, which in part, may underlie sex

  18. Effects of Oxytocin on Neural Response to Facial Expressions in Patients with Schizophrenia.

    PubMed

    Shin, Na Young; Park, Hye Yoon; Jung, Wi Hoon; Park, Jin Woo; Yun, Je-Yeon; Jang, Joon Hwan; Kim, Sung Nyun; Han, Hyun Jung; Kim, So-Yeon; Kang, Do-Hyung; Kwon, Jun Soo

    2015-07-01

    Impaired facial emotion recognition is a core deficit in schizophrenia. Oxytocin has been shown to improve social perception in patients with schizophrenia; however, the effect of oxytocin on the neural activity underlying facial emotion recognition has not been investigated. This study was aimed to assess the effect of a single dose of intranasal oxytocin on brain activity in patients with schizophrenia using an implicit facial emotion-recognition paradigm. Sixteen male patients with schizophrenia and 16 age-matched healthy male control subjects participated in a randomized, double-blind, placebo-controlled crossover trial at Seoul National University Hospital. Delivery of a single dose of 40 IU intranasal oxytocin and the placebo was separated by 1 week. Drug conditions were compared by performing a region of interest (ROI) analysis of the bilateral amygdala on responses to the emotion recognition test. It was found that nasal spray decreased amygdala activity for fearful emotion and increased activity for happy faces. Further, oxytocin elicited differential effects between the patient and control groups. Intranasal oxytocin attenuated amygdala activity for emotional faces in patients with schizophrenia, whereas intranasal oxytocin significantly increased amygdala activity in healthy controls. Oxytocin-induced BOLD signal changes in amygdala in response to happy faces was related to attachment style in the control group. Our result provides new evidence of a modulatory effect of oxytocin on neural response to emotional faces for patients with schizophrenia. Future studies are needed to investigate the effectiveness of long-term treatment with intranasal oxytocin on neural activity in patients with schizophrenia.

  19. Sex Differences in Neural Responses to Stress and Alcohol Context Cues

    PubMed Central

    Seo, Dongju; Jia, Zhiru; Lacadie, Cheryl M.; Tsou, Kristen A.; Bergquist, Keri; Sinha, Rajita

    2011-01-01

    Stress and alcohol context cues are each associated with alcohol-related behaviors, yet neural responses underlying these processes remain unclear. The present study investigated the neural correlates of stress and alcohol context cue experiences and examined sex differences in these responses. Using functional magnetic resonance imaging, brain responses were examined while 43 right-handed, socially drinking, healthy individuals (23 females) engaged in brief guided imagery of personalized stress, alcohol-cue and neutral-relaxing scenarios. Stress and alcohol-cue exposure increased activity in the cortico-limbic-striatal circuit (p<.01, corrected), encompassing the medial prefrontal cortex (mPFC), orbitofrontal cortex (OFC), anterior cingulate cortex (ACC), left anterior insula, striatum and visuomotor regions (parietal and occipital lobe, and cerebellum). Activity in the right dorsal striatum increased during stress, while bilateral ventral striatum activity was evident during alcohol-cue exposure. Men displayed greater stress-related activations in the mPFC, rostral ACC, posterior insula, amygdala and hippocampus than women, whereas women showed greater alcohol-cue related activity in the superior and middle frontal gyrus (SFG/MFG) than men. Stress-induced anxiety was positively associated with activity in emotion modulation regions, including the medial OFC, ventromedial PFC, left superior-medial PFC and rostral ACC in men, but in women with activation in the SFG/MFG, regions involved in cognitive processing. Alcohol craving was significantly associated with the striatum (encompassing dorsal and ventral) in men, supporting its involvement in alcohol ‘urge’ in healthy men. These results indicate sex differences in neural processing of stress and alcohol-cue experiences, and have implications for sex-specific vulnerabilities to stress- and alcohol-related psychiatric disorders. PMID:21162046

  20. Prestin's role in cochlear frequency tuning and transmission of mechanical responses to neural excitation.

    PubMed

    Mellado Lagarde, Marcia M; Drexl, Markus; Lukashkin, Andrei N; Zuo, Jian; Russell, Ian J

    2008-02-12

    The remarkable power amplifier [1] of the cochlea boosts low-level and compresses high-level vibrations of the basilar membrane (BM) [2]. By contributing maximally at the characteristic frequency (CF) of each point along its length, the amplifier ensures the exquisite sensitivity, narrow frequency tuning, and enormous dynamic range of the mammalian cochlea. The motor protein prestin in the outer hair cell (OHC) lateral membrane is a prime candidate for the cochlear power amplifier [3]. The other contender for this role is the ubiquitous calcium-mediated motility of the hair cell stereocilia, which has been demonstrated in vitro and is based on fast adaptation of the mechanoelectrical transduction channels [4, 5]. Absence of prestin [6] from OHCs results in a 40-60 dB reduction in cochlear neural sensitivity [7]. Here we show that sound-evoked BM vibrations in the high-frequency region of prestin(-/-) mice cochleae are, surprisingly, as sensitive as those of their prestin(+/+) siblings. The BM vibrations of prestin(-/-) mice are, however, broadly tuned to a frequency approximately a half octave below the CF of prestin(+/+) mice at similar BM locations. The peak sensitivity of prestin(+/+) BM tuning curves matches the neural thresholds. In contrast, prestin(-/-) BM tuning curves at their best frequency are >50 dB more sensitive than the neural responses. We propose that the absence of prestin from OHCs, and consequent reduction in stiffness of the cochlea partition, changes the passive impedance of the BM at high frequencies, including the CF. We conclude that prestin influences the cochlear partition's dynamic properties that permit transmission of its vibrations into neural excitation. Prestin is crucial for defining sharp and sensitive cochlear frequency tuning by reducing the sensitivity of the low-frequency tail of the tuning curve, although this necessitates a cochlear amplifier to determine the narrowly tuned tip.

  1. Meiotic abnormalities

    SciTech Connect

    1993-12-31

    Chapter 19, describes meiotic abnormalities. These include nondisjunction of autosomes and sex chromosomes, genetic and environmental causes of nondisjunction, misdivision of the centromere, chromosomally abnormal human sperm, male infertility, parental age, and origin of diploid gametes. 57 refs., 2 figs., 1 tab.

  2. Learning of new sound categories shapes neural response patterns in human auditory cortex.

    PubMed

    Ley, Anke; Vroomen, Jean; Hausfeld, Lars; Valente, Giancarlo; De Weerd, Peter; Formisano, Elia

    2012-09-19

    The formation of new sound categories is fundamental to everyday goal-directed behavior. Categorization requires the abstraction of discrete classes from continuous physical features as required by context and task. Electrophysiology in animals has shown that learning to categorize novel sounds alters their spatiotemporal neural representation at the level of early auditory cortex. However, functional magnetic resonance imaging (fMRI) studies so far did not yield insight into the effects of category learning on sound representations in human auditory cortex. This may be due to the use of overlearned speech-like categories and fMRI subtraction paradigms, leading to insufficient sensitivity to distinguish the responses to learning-induced, novel sound categories. Here, we used fMRI pattern analysis to investigate changes in human auditory cortical response patterns induced by category learning. We created complex novel sound categories and analyzed distributed activation patterns during passive listening to a sound continuum before and after category learning. We show that only after training, sound categories could be successfully decoded from early auditory areas and that learning-induced pattern changes were specific to the category-distinctive sound feature (i.e., pitch). Notably, the similarity between fMRI response patterns for the sound continuum mirrored the sigmoid shape of the behavioral category identification function. Our results indicate that perceptual representations of novel sound categories emerge from neural changes at early levels of the human auditory processing hierarchy.

  3. Gender Differences in Neural Responses to Perceptually Invisible Fearful Face-An ERP Study.

    PubMed

    Lee, Seung A; Kim, Chai-Youn; Shim, Miseon; Lee, Seung-Hwan

    2017-01-01

    Women tend to respond to emotional stimuli differently from men. This study aimed at investigating whether neural responses to perceptually "invisible" emotional stimuli differ between men and women by exploiting event-related potential (ERP). Forty healthy participants (21 women) were recruited for the main experiment. A control experiment was conducted by excluding nine (7 women) participants from the main experiment and replacing them with additional ten (6 women) participants (total 41 participants) where Beck's Anxiety Inventory (BAI) and Beck's Depression Inventory (BDI) scores were controlled. Using the visual backward masking paradigm, either a fearful or a neutral face stimulus was presented in varied durations (subthreshold, near-threshold, or suprathreshold) followed by a mask. Participants performed a two-alternative forced choice (2-AFC) emotion discrimination task on each face. Behavioral analysis showed that participants were unaware of masked stimuli of which duration was the shortest and, therefore, processed at subthreshold. Nevertheless, women showed significantly larger response in P100 amplitude to subthreshold fearful faces than men. This result remained consistent in the control experiment. Our findings indicate gender-differences in neural response to subthreshold emotional face, which is reflected in the early processing stage.

  4. Gender Differences in Neural Responses to Perceptually Invisible Fearful Face—An ERP Study

    PubMed Central

    Lee, Seung A.; Kim, Chai-Youn; Shim, Miseon; Lee, Seung-Hwan

    2017-01-01

    Women tend to respond to emotional stimuli differently from men. This study aimed at investigating whether neural responses to perceptually “invisible” emotional stimuli differ between men and women by exploiting event-related potential (ERP). Forty healthy participants (21 women) were recruited for the main experiment. A control experiment was conducted by excluding nine (7 women) participants from the main experiment and replacing them with additional ten (6 women) participants (total 41 participants) where Beck's Anxiety Inventory (BAI) and Beck's Depression Inventory (BDI) scores were controlled. Using the visual backward masking paradigm, either a fearful or a neutral face stimulus was presented in varied durations (subthreshold, near-threshold, or suprathreshold) followed by a mask. Participants performed a two-alternative forced choice (2-AFC) emotion discrimination task on each face. Behavioral analysis showed that participants were unaware of masked stimuli of which duration was the shortest and, therefore, processed at subthreshold. Nevertheless, women showed significantly larger response in P100 amplitude to subthreshold fearful faces than men. This result remained consistent in the control experiment. Our findings indicate gender-differences in neural response to subthreshold emotional face, which is reflected in the early processing stage. PMID:28184189

  5. Neural control of cardiovascular responses and of ventilation during dynamic exercise in man.

    PubMed Central

    Strange, S; Secher, N H; Pawelczyk, J A; Karpakka, J; Christensen, N J; Mitchell, J H; Saltin, B

    1993-01-01

    1. Nine subjects performed dynamic knee extension by voluntary muscle contractions and by evoked contractions with and without epidural anaesthesia. Four exercise bouts of 10 min each were performed: three of one-legged knee extension (10, 20 and 30 W) and one of two-legged knee extension at 2 x 20 W. Epidural anaesthesia was induced with 0.5% bupivacaine or 2% lidocaine. Presence of neural blockade was verified by cutaneous sensory anaesthesia below T8-T10 and complete paralysis of both legs. 2. Compared to voluntary exercise, control electrically induced exercise resulted in normal or enhanced cardiovascular, metabolic and ventilatory responses. However, during epidural anaesthesia the increase in blood pressure with exercise was abolished. Furthermore, the increases in heart rate, cardiac output and leg blood flow were reduced. In contrast, plasma catecholamines, leg glucose uptake and leg lactate release, arterial carbon dioxide tension and pulmonary ventilation were not affected. Arterial and venous plasma potassium concentrations became elevated but leg potassium release was not increased. 3. The results conform to the idea that a reflex originating in contracting muscle is essential for the normal blood pressure response to dynamic exercise, and that other neural, humoral and haemodynamic mechanisms cannot govern this response. However, control mechanisms other than central command and the exercise pressor reflex can influence heart rate, cardiac output, muscle blood flow and ventilation during dynamic exercise in man. PMID:8308750

  6. Bayesian Mapping Reveals That Attention Boosts Neural Responses to Predicted and Unpredicted Stimuli.

    PubMed

    Garrido, Marta I; Rowe, Elise G; Halász, Veronika; Mattingley, Jason B

    2017-04-10

    Predictive coding posits that the human brain continually monitors the environment for regularities and detects inconsistencies. It is unclear, however, what effect attention has on expectation processes, as there have been relatively few studies and the results of these have yielded contradictory findings. Here, we employed Bayesian model comparison to adjudicate between 2 alternative computational models. The "Opposition" model states that attention boosts neural responses equally to predicted and unpredicted stimuli, whereas the "Interaction" model assumes that attentional boosting of neural signals depends on the level of predictability. We designed a novel, audiospatial attention task that orthogonally manipulated attention and prediction by playing oddball sequences in either the attended or unattended ear. We observed sensory prediction error responses, with electroencephalography, across all attentional manipulations. Crucially, posterior probability maps revealed that, overall, the Opposition model better explained scalp and source data, suggesting that attention boosts responses to predicted and unpredicted stimuli equally. Furthermore, Dynamic Causal Modeling showed that these Opposition effects were expressed in plastic changes within the mismatch negativity network. Our findings provide empirical evidence for a computational model of the opposing interplay of attention and expectation in the brain.

  7. Neural responses to sounds presented on and off the beat of ecologically valid music

    PubMed Central

    Tierney, Adam; Kraus, Nina

    2013-01-01

    The tracking of rhythmic structure is a vital component of speech and music perception. It is known that sequences of identical sounds can give rise to the percept of alternating strong and weak sounds, and that this percept is linked to enhanced cortical and oscillatory responses. The neural correlates of the perception of rhythm elicited by ecologically valid, complex stimuli, however, remain unexplored. Here we report the effects of a stimulus' alignment with the beat on the brain's processing of sound. Human subjects listened to short popular music pieces while simultaneously hearing a target sound. Cortical and brainstem electrophysiological onset responses to the sound were enhanced when it was presented on the beat of the music, as opposed to shifted away from it. Moreover, the size of the effect of alignment with the beat on the cortical response correlated strongly with the ability to tap to a beat, suggesting that the ability to synchronize to the beat of simple isochronous stimuli and the ability to track the beat of complex, ecologically valid stimuli may rely on overlapping neural resources. These results suggest that the perception of musical rhythm may have robust effects on processing throughout the auditory system. PMID:23717268

  8. Functional recognition imaging using artificial neural networks: applications to rapid cellular identification via broadband electromechanical response

    NASA Astrophysics Data System (ADS)

    Nikiforov, M. P.; Reukov, V. V.; Thompson, G. L.; Vertegel, A. A.; Guo, S.; Kalinin, S. V.; Jesse, S.

    2009-10-01

    Functional recognition imaging in scanning probe microscopy (SPM) using artificial neural network identification is demonstrated. This approach utilizes statistical analysis of complex SPM responses at a single spatial location to identify the target behavior, which is reminiscent of associative thinking in the human brain, obviating the need for analytical models. We demonstrate, as an example of recognition imaging, rapid identification of cellular organisms using the difference in electromechanical activity over a broad frequency range. Single-pixel identification of model Micrococcus lysodeikticus and Pseudomonas fluorescens bacteria is achieved, demonstrating the viability of the method.

  9. Decreased B and T lymphocyte attenuator in Behcet’s disease may trigger abnormal Th17 and Th1 immune responses

    PubMed Central

    Ye, Zi; Deng, Bolin; Wang, Chaokui; Zhang, Dike; Kijlstra, Aize; Yang, Peizeng

    2016-01-01

    Behcet’s disease (BD) is a chronic, systemic and recurrent inflammatory disease associated with hyperactive Th17 and Th1 immune responses. Recent studies have shown that B and T lymphocyte attenuator (BTLA) negatively regulates the immune response. In this study, we investigated whether BTLA activation could be exploited to inhibit the development of abnormal immune responses in BD patients. BTLA expression in PBMCs and CD4+ T cells was significantly decreased in active BD patients. Decreased BTLA level was associated with increased Th17 and Th1 responses. Activation of BTLA inhibited the abnormal Th17 and Th1 responses and IL-22 expression in both patients and controls. Addition of an agonistic anti-BTLA antibody remarkably inhibited DC-induced Th17 and Th1 cell responses, resulted in decreased production of the Th17 and Th1-related cytokines IL-1beta, IL-6, IL-23 and IL-12p70 and reduced CD40 expression in DCs. In conclusion, decreased BTLA expression in ocular BD may lead to inappropriate control of the Th17 and Th1 immune responses and DC functions. Therefore, BTLA may be involved in the development and recurrence of this disease. Agonistic agents of BTLA may represent a potential therapeutic approach for the treatment of BD and other inflammatory diseases mediated by abnormal Th17 and Th1 immune responses. PMID:26841832

  10. Corticostriatal response selection in sentence production: Insights from neural network simulation with reservoir computing.

    PubMed

    Hinaut, Xavier; Lance, Florian; Droin, Colas; Petit, Maxime; Pointeau, Gregoire; Dominey, Peter Ford

    2015-11-01

    Language production requires selection of the appropriate sentence structure to accommodate the communication goal of the speaker - the transmission of a particular meaning. Here we consider event meanings, in terms of predicates and thematic roles, and we address the problem that a given event can be described from multiple perspectives, which poses a problem of response selection. We present a model of response selection in sentence production that is inspired by the primate corticostriatal system. The model is implemented in the context of reservoir computing where the reservoir - a recurrent neural network with fixed connections - corresponds to cortex, and the readout corresponds to the striatum. We demonstrate robust learning, and generalization properties of the model, and demonstrate its cross linguistic capabilities in English and Japanese. The results contribute to the argument that the corticostriatal system plays a role in response selection in language production, and to the stance that reservoir computing is a valid potential model of corticostriatal processing.

  11. Artificial neural network study of whole-cell bacterial bioreporter response determined using fluorescence flow cytometry.

    PubMed

    Busam, Sirisha; McNabb, Maia; Wackwitz, Anke; Senevirathna, Wasana; Beggah, Siham; Meer, Jan Roelof van der; Wells, Mona; Breuer, Uta; Harms, Hauke

    2007-12-01

    Genetically engineered bioreporters are an excellent complement to traditional methods of chemical analysis. The application of fluorescence flow cytometry to detection of bioreporter response enables rapid and efficient characterization of bacterial bioreporter population response on a single-cell basis. In the present study, intrapopulation response variability was used to obtain higher analytical sensitivity and precision. We have analyzed flow cytometric data for an arsenic-sensitive bacterial bioreporter using an artificial neural network-based adaptive clustering approach (a single-layer perceptron model). Results for this approach are far superior to other methods that we have applied to this fluorescent bioreporter (e.g., the arsenic detection limit is 0.01 microM, substantially lower than for other detection methods/algorithms). The approach is highly efficient computationally and can be implemented on a real-time basis, thus having potential for future development of high-throughput screening applications.

  12. Well-differentiated systemic mastocytosis showed excellent clinical response to imatinib in the absence of known molecular genetic abnormalities

    PubMed Central

    Huang, Lanshan; Wang, Sa A.; Konoplev, Sergej; Bueso-Ramos, Carlos E.; Thakral, Beenu; Miranda, Roberto N.; Jabbour, Elias; Medeiros, L. Jeffrey; Kanagal-Shamanna, Rashmi

    2016-01-01

    Abstract Introduction: Well-differentiated systemic mastocytosis (WDSM) is a rare, recently recognized provisional subvariant of systemic mastocytosis (SM). We report a case of WDSM that showed excellent clinical and cutaneous response to imatinib in the absence of known molecular genetic abnormalities. Clinical Findings/Diagnoses: We present a 24-year-old woman with childhood onset of skin manifestations that progressed to mediator-related systemic events, and a gastrointestinal tract mastocytoma. A subsequent bone marrow examination showed WDSM. Treatment with imatinib resulted in complete resolution of cutaneous lesions and systemic symptoms, which relapsed with the discontinuation of the drug. Targeted next-generation sequencing-based mutation analysis did not demonstrate any mutations in the coding regions of KIT or other genes commonly associated with myeloid neoplasms. Conclusions: The diagnosis of WDSM is challenging in the absence of spindle-shaped mast cells, CD2 or CD25 expression, and KIT D816 mutation. This case illustrated the need for recognizing this unique variant of SM for diagnostic and therapeutic implications. PMID:27741105

  13. Relationship between Parental Feeding Practices and Neural Responses to Food Cues in Adolescents.

    PubMed

    Allen, Harriet A; Chambers, Alison; Blissett, Jacqueline; Chechlacz, Magdalena; Barrett, Timothy; Higgs, Suzanne; Nouwen, Arie

    2016-01-01

    parental teaching and modelling of behaviour. Parental restrictive feeding and parental teaching and modelling affected neural responses to food cues in different ways, depending on motivations and diagnoses, illustrating a social influence on neural responses to food cues.

  14. Relationship between Parental Feeding Practices and Neural Responses to Food Cues in Adolescents

    PubMed Central

    Chambers, Alison; Blissett, Jacqueline; Chechlacz, Magdalena; Barrett, Timothy; Higgs, Suzanne; Nouwen, Arie

    2016-01-01

    parental teaching and modelling of behaviour. Parental restrictive feeding and parental teaching and modelling affected neural responses to food cues in different ways, depending on motivations and diagnoses, illustrating a social influence on neural responses to food cues. PMID:27479051

  15. Fast response and high sensitivity to microsaccades in a cascading-adaptation neural network with short-term synaptic depression.

    PubMed

    Yuan, Wu-Jie; Zhou, Jian-Fang; Zhou, Changsong

    2016-04-01

    Microsaccades are very small eye movements during fixation. Experimentally, they have been found to play an important role in visual information processing. However, neural responses induced by microsaccades are not yet well understood and are rarely studied theoretically. Here we propose a network model with a cascading adaptation including both retinal adaptation and short-term depression (STD) at thalamocortical synapses. In the neural network model, we compare the microsaccade-induced neural responses in the presence of STD and those without STD. It is found that the cascading with STD can give rise to faster and sharper responses to microsaccades. Moreover, STD can enhance response effectiveness and sensitivity to microsaccadic spatiotemporal changes, suggesting improved detection of small eye movements (or moving visual objects). We also explore the mechanism of the response properties in the model. Our studies strongly indicate that STD plays an important role in neural responses to microsaccades. Our model considers simultaneously retinal adaptation and STD at thalamocortical synapses in the study of microsaccade-induced neural activity, and may be useful for further investigation of the functional roles of microsaccades in visual information processing.

  16. Model predictions of features in microsaccade-related neural responses in a feedforward network with short-term synaptic depression

    NASA Astrophysics Data System (ADS)

    Zhou, Jian-Fang; Yuan, Wu-Jie; Zhou, Zhao; Zhou, Changsong

    2016-02-01

    Recently, the significant microsaccade-induced neural responses have been extensively observed in experiments. To explore the underlying mechanisms of the observed neural responses, a feedforward network model with short-term synaptic depression has been proposed [Yuan, W.-J., Dimigen, O., Sommer, W. and Zhou, C. Front. Comput. Neurosci. 7, 47 (2013)]. The depression model not only gave an explanation for microsaccades in counteracting visual fading, but also successfully reproduced several microsaccade-related features in experimental findings. These results strongly suggest that, the depression model is very useful to investigate microsaccade-related neural responses. In this paper, by using the model, we extensively study and predict the dependance of microsaccade-related neural responses on several key parameters, which could be tuned in experiments. Particularly, we provide a significant prediction that microsaccade-related neural response also complies with the property “sharper is better” observed in many contexts in neuroscience. Importantly, the property exhibits a power-law relationship between the width of input signal and the responsive effectiveness, which is robust against many parameters in the model. By using mean field theory, we analytically investigate the robust power-law property. Our predictions would give theoretical guidance for further experimental investigations of the functional role of microsaccades in visual information processing.

  17. Individual differences in risk preference predict neural responses during financial decision-making.

    PubMed

    Engelmann, Jan B; Tamir, Diana

    2009-09-22

    We investigated the neural correlates of subjective valuations during a task involving risky choices about lotteries. Because expected value was held constant across all lotteries, decisions were influenced by subjective preferences, which manifest behaviorally as risk-seeking or risk-averse attitudes. To isolate structures encoding risk preference during choice, we probed for areas showing increased activation as a function of selected risk-level. Such response patterns were obtained in anterior (ACC) and posterior cingulate cortex (PCC), superior frontal gyrus, caudate nucleus, and substantia nigra. Behavioral results revealed the presence of risk-averse and risk-neutral individuals. In parallel, brain signals revealed modulation of activity by risk attitude during choice. Correlations between risk-seeking attitudes and neural activity during risky choice were obtained in superior and inferior frontal gyri, medial and lateral orbitofrontal cortex, and parahippocampal gyrus, while correlations with risk-averse attitudes were found in the caudate. The dynamics of neural responses relevant to each stage of the task (decision, anticipation, outcome) were investigated via timeseries and conjunction analyses. Though the networks engaged in each of the task stages were mostly distinct, regions within ACC, PCC and caudate were consistently activated during each decision-making phase. These results demonstrate (1) that subjective assessments of risk, as well as individual attitudes toward risk, play a significant role in modulating activity within brain regions recruited during decision-making, and (2) that ACC, PCC and caudate are relevant during each phase of a decision-making task requiring subjective valuations, strengthening the role of these regions in self-referential subjective valuations during choice.

  18. A neural correlate of visceral emotional responses: evidence from fMRI of the thoracic spinal cord

    PubMed Central

    Smith, Stephen D.; McIver, Theresa A.

    2015-01-01

    Functional magnetic resonance imaging (fMRI) of thoracic spinal cord neurons was used to examine the neural correlates of visceral emotional responses. Participants completed four spinal fMRI runs involving passive viewing (i.e. no movement) and motoric responses to negative or neutral images. Negative images, particularly in the movement condition, elicited robust activity in motoric nuclei, indicating ‘action preparedness’. These images also enhanced activity in autonomic and sensory nuclei, thus providing a clear neural representation of visceral responses to emotional stimuli. PMID:24993101

  19. Artificial neural network model for the prediction of obsessive-compulsive disorder treatment response.

    PubMed

    Salomoni, Giuliana; Grassi, Massimiliano; Mosini, Paola; Riva, Patrizia; Cavedini, Paolo; Bellodi, Laura

    2009-08-01

    Several patients with obsessive-compulsive disorder (OCD) who are refractory to adequate treatment with first-line treatments are considered treatment-resistant. Further surveys were to be implemented to explore the outcome predictors of the antiobsessional response. Such study was aimed at building a model suitable to predict the final outcome of a mixed OCD pharmacologic and nonpharmacologic treatment approaches. We studied 130 subjects with OCD who underwent pharmacologic (with selective serotonin reuptake inhibitors alone or with selective serotonin reuptake inhibitors and risperidone at low dosage) and/or behavioral therapy (using exposure and response prevention techniques). The following variables were used as predictors: symptoms dimension, as resulting from the Yale-Brown Obsessive-Compulsive Scale items factor analysis; neuropsychologic performances; and epidemiologic variables. The treatment response arising from 3 to 6 months of therapy was used as dependent variable. A conventional logistic regression was used to define a previsional model of treatment response and multilayer perceptrons and to supervise an artificial neural network technique. The 46.9% of the sample resulted to be refractory to treatment. Results obtained with the logistic regression model showed that the only predictors of treatment outcome are hoarding symptoms, repeating rituals, and counting compulsions. Furthermore, using all the variables considered in the models, multilayer perceptrons showed highly better predictive performance as compared with the logistic regression models (93.3% vs 61.5%, respectively, of correct classification of cases). Complex interactions between different clinical and neuropsychologic variables are involved in defining OCD treatment response profile, and nonlinear and interactive modeling strategies, that is, supervised artificial neural networks, seem to be more suitable to investigate this complexity than linear techniques.

  20. Monetary favors and their influence on neural responses and revealed preference.

    PubMed

    Harvey, Ann H; Kirk, Ulrich; Denfield, George H; Montague, P Read

    2010-07-14

    Favors from a sender to a receiver are known to bias decisions made by the recipient, especially when the decision relates to the sender, a feature of social exchange known as reciprocity. Using an art-viewing paradigm possessing no objectively correct answer for preferring one piece of art over another, we show that sponsorship of the experiment by a company endows the logo of the company with the capacity to bias revealed preference for art displayed next to the logo. Merely offering to sponsor the experiment similarly endowed the gesturing logo of the company with the capacity to bias revealed preferences. These effects do not depend upon the size of the displayed art or the proximity of the sponsoring logo to the piece of art. We used functional magnetic resonance imaging to show that such monetary favors do not modulate a special collection of brain responses but instead modulate responses in neural networks normally activated by a wide range of preference judgments. The results raise the important possibility that monetary favors bias judgments in domains seemingly unrelated to the favor but nevertheless act in an implicit way through neural networks that underlie normal, ongoing preference judgments.

  1. The impoverished brain: disparities in maternal education affect the neural response to sound.

    PubMed

    Skoe, Erika; Krizman, Jennifer; Kraus, Nina

    2013-10-30

    Despite the prevalence of poverty worldwide, little is known about how early socioeconomic adversity affects auditory brain function. Socioeconomically disadvantaged children are underexposed to linguistically and cognitively stimulating environments and overexposed to environmental toxins, including noise pollution. This kind of sensory impoverishment, we theorize, has extensive repercussions on how the brain processes sound. To characterize how this impoverishment affects auditory brain function, we compared two groups of normal-hearing human adolescents who attended the same schools and who were matched in age, sex, and ethnicity, but differed in their maternal education level, a correlate of socioeconomic status (SES). In addition to lower literacy levels and cognitive abilities, adolescents from lower maternal education backgrounds were found to have noisier neural activity than their classmates, as reflected by greater activity in the absence of auditory stimulation. Additionally, in the lower maternal education group, the neural response to speech was more erratic over repeated stimulation, with lower fidelity to the input signal. These weaker, more variable, and noisier responses are suggestive of an inefficient auditory system. By studying SES within a neuroscientific framework, we have the potential to expand our understanding of how experience molds the brain, in addition to informing intervention research aimed at closing the achievement gap between high-SES and low-SES children.

  2. Beyond emotions: A meta-analysis of neural response within face processing system in social anxiety

    PubMed Central

    Gentili, Claudio; Cristea, Ioana Alina; Angstadt, Mike; Klumpp, Heide; Tozzi, Leonardo; Phan, K Luan

    2015-01-01

    Patients with social anxiety disorder (SAD) experience anxiety and avoidance in face-to-face interactions. We performed a meta-analysis of functional magnetic resonance imaging (fMRI) studies in SAD to provide a comprehensive understanding of the neural underpinnings of face perception in this disorder. To this purpose, we adopted an innovative approach, asking authors for unpublished data. This is a common procedure for behavioral meta-analyses, which, however has never been used in neuroimaging studies. We searched Pubmed with the key words “Social Anxiety AND faces” and “Social Phobia AND faces.” Then, we selected those fMRI studies for which we were able to obtain data for the comparison between SAD and healthy controls (HC) in a face perception task, either from the published papers or from the authors themselves. In this way, we obtained 23 studies (totaling 449 SAD and 424 HC individuals). We identified significant clusters in which faces evoked a higher response in SAD in bilateral amygdala, globus pallidus, superior temporal sulcus, visual cortex, and prefrontal cortex. We also found a higher activity for HC in the lingual gyrus and in the posterior cingulate. Our findings show that altered neural response to face in SAD is not limited to emotional structures but involves a complex network. These results may have implications for the understanding of SAD pathophysiology, as they suggest that a dysfunctional face perception process may bias patient person-to-person interactions. PMID:26341469

  3. Branding and a child's brain: an fMRI study of neural responses to logos.

    PubMed

    Bruce, Amanda S; Bruce, Jared M; Black, William R; Lepping, Rebecca J; Henry, Janice M; Cherry, Joseph Bradley C; Martin, Laura E; Papa, Vlad B; Davis, Ann M; Brooks, William M; Savage, Cary R

    2014-01-01

    Branding and advertising have a powerful effect on both familiarity and preference for products, yet no neuroimaging studies have examined neural response to logos in children. Food advertising is particularly pervasive and effective in manipulating choices in children. The purpose of this study was to examine how healthy children's brains respond to common food and other logos. A pilot validation study was first conducted with 32 children to select the most culturally familiar logos, and to match food and non-food logos on valence and intensity. A new sample of 17 healthy weight children were then scanned using functional magnetic resonance imaging. Food logos compared to baseline were associated with increased activation in orbitofrontal cortex and inferior prefrontal cortex. Compared to non-food logos, food logos elicited increased activation in posterior cingulate cortex. Results confirmed that food logos activate some brain regions in children known to be associated with motivation. This marks the first study in children to examine brain responses to culturally familiar logos. Considering the pervasiveness of advertising, research should further investigate how children respond at the neural level to marketing.

  4. Actor-recipient role affects neural responses to self in emotional situations

    PubMed Central

    Wang, Xiaoyan; Zheng, Li; Cheng, Xuemei; Li, Lin; Sun, Lining; Wang, Qianfeng; Guo, Xiuyan

    2015-01-01

    People often take either the role of an actor or that of recipient in positive and negative interpersonal events when they interact with others. The present study investigated how the actor-recipient role affected the neural responses to self in emotional situations. Twenty-five participants were scanned while they were presented with positive and negative interpersonal events and were asked to rate the degree to which the actor/the recipient was that kind of person who caused the interpersonal event. Half of the trials were self-relevant events and the other half were other-relevant events. Results showed that people were more likely to isolate self from negative events when they played the role of actor relative to recipient. Pregenual anterior cingulate cortex (pgACC) and posterior dorsal anterior cingulate cortex (pdACC) were more active for self than other only in negative events. More importantly, also in negative interpersonal events, dorsal medial prefrontal cortex (dmPFC) showed greater self-related activations (self-other) when participants played the role of recipient relative to actor, while activities in orbitofrontal cortex (OFC) were greater for self than other only when the evaluation target played the role of recipient. These results showed that the actor-recipient role affected neural responses to self in emotional situations, especially when a recipient role was played in negative situations. PMID:25926781

  5. Effects of a body-oriented response measure on the neural substrate of imagined perspective rotations.

    PubMed

    Wraga, Maryjane; Flynn, Catherine M; Boyle, Holly K; Evans, Gretchen C

    2010-08-01

    Previous behavioral studies suggest that response measures related to the body, such as pointing, serve to anchor participants to their physical body during mental rotation tasks in which their perspective must be shifted elsewhere. This study investigated whether such measures engage spatial and low-level cortical motor areas of the brain more readily than non-body-related measures. We directly compared activation found in two imagined perspective rotation tasks, using responses that varied in the degree to which they emphasized the human body. In the body minimize condition, participants imagined rotating themselves around an object and judged whether a prescribed part of the object would be visible from the imagined viewpoint. In the body maximize condition, participants imagined rotating around the object and then located the prescribed object part with respect to their bodies. A direct comparison of neural activation in both conditions revealed distinct yet overlapping neural regions. The body maximize condition yielded activation in low-level cortical motor areas such as premotor cortex and primary motor cortex, as well as bilateral spatial processing areas. The body minimize condition yielded activation in nonmotoric egocentric processing regions. However, both conditions showed activation in the parietal-occipital region that is thought to be involved in egocentric transformations. These findings are discussed in the context of recent hypotheses regarding the role of the body percept in imagined egocentric transformations.

  6. Computational analysis of binding affinity and neural response at the l-alanine receptor

    NASA Astrophysics Data System (ADS)

    Venanzi, Thomas J.; Bryant, Bruce P.; Venanzi, Carol A.

    1995-10-01

    A model of analogue-receptor binding is developed for the l-alanine receptor in the channel catfish using the AM1-SM2 and ab initio SCRF computational methods. Besides interactions involving the zwitterionic moiety of the amino acid analogue and complementary subsites on the receptor, the model suggests the presence of a hydrophobic pocket with dispersion interactions between the receptor and the residue on the amino acid analogue. Conformational analysis suggests not only a small compact active site on the receptor, but also that the analogues with the highest affinity occupy nearly identical regions of space. Although the binding interaction is dominated by the ionic terms, AM1-SM2 calculations indicate that free energy terms associated with cavity formation, solvent reorganization, and dispersion interactions can be correlated to activation and neural response. From a consideration of this model, molecular features of the analogues that are important for binding and neural response were deduced and other analogues or ligands were developed and tested.

  7. Actor-recipient role affects neural responses to self in emotional situations.

    PubMed

    Wang, Xiaoyan; Zheng, Li; Cheng, Xuemei; Li, Lin; Sun, Lining; Wang, Qianfeng; Guo, Xiuyan

    2015-01-01

    People often take either the role of an actor or that of recipient in positive and negative interpersonal events when they interact with others. The present study investigated how the actor-recipient role affected the neural responses to self in emotional situations. Twenty-five participants were scanned while they were presented with positive and negative interpersonal events and were asked to rate the degree to which the actor/the recipient was that kind of person who caused the interpersonal event. Half of the trials were self-relevant events and the other half were other-relevant events. Results showed that people were more likely to isolate self from negative events when they played the role of actor relative to recipient. Pregenual anterior cingulate cortex (pgACC) and posterior dorsal anterior cingulate cortex (pdACC) were more active for self than other only in negative events. More importantly, also in negative interpersonal events, dorsal medial prefrontal cortex (dmPFC) showed greater self-related activations (self-other) when participants played the role of recipient relative to actor, while activities in orbitofrontal cortex (OFC) were greater for self than other only when the evaluation target played the role of recipient. These results showed that the actor-recipient role affected neural responses to self in emotional situations, especially when a recipient role was played in negative situations.

  8. Like or dislike? Affective preference modulates neural response to others' gains and losses.

    PubMed

    Wang, Yang; Qu, Chen; Luo, Qiuling; Qu, Lulu; Li, Xuebing

    2014-01-01

    Previous studies have demonstrated that the brain responds differentially to others' gains and losses relative to one's own, moderated by social context factors such as competition and interpersonal relationships. In the current study, we tested the hypothesis that the neural response to others' outcomes could be modulated by a short-term induced affective preference. We engaged 17 men and 18 women in a social-exchange game, in which two confederates played fairly or unfairly. Both men and women rated the fair player as likable and the unfair players as unlikable. Afterwards, ERPs were recorded while participants observed each confederates playing a gambling game individually. This study examines feedback related negativity (FRN), an ERP component sensitive to negative feedback. ANOVA showed a significant interaction in which females but not males displayed stronger FRNs when observing likable players' outcomes compared to unlikable ones'. However, males did not respond differently under either circumstance. These findings suggest that, at least in females, the neural response is influenced by a short-term induced affective preference.

  9. Motivation alters response bias and neural activation patterns in a perceptual decision-making task.

    PubMed

    Reckless, G E; Bolstad, I; Nakstad, P H; Andreassen, O A; Jensen, J

    2013-05-15

    Motivation has been demonstrated to affect individuals' response strategies in economic decision-making, however, little is known about how motivation influences perceptual decision-making behavior or its related neural activity. Given the important role motivation plays in shaping our behavior, a better understanding of this relationship is needed. A block-design, continuous performance, perceptual decision-making task where participants were asked to detect a picture of an animal among distractors was used during functional magnetic resonance imaging (fMRI). The effect of positive and negative motivation on sustained activity within regions of the brain thought to underlie decision-making was examined by altering the monetary contingency associated with the task. In addition, signal detection theory was used to investigate the effect of motivation on detection sensitivity, response bias and response time. While both positive and negative motivation resulted in increased sustained activation in the ventral striatum, fusiform gyrus, left dorsolateral prefrontal cortex (DLPFC) and ventromedial prefrontal cortex, only negative motivation resulted in the adoption of a more liberal, closer to optimal response bias. This shift toward a liberal response bias correlated with increased activation in the left DLPFC, but did not result in improved task performance. The present findings suggest that motivation alters aspects of the way perceptual decisions are made. Further, this altered response behavior is reflected in a change in left DLPFC activation, a region involved in the computation of perceptual decisions.

  10. Natural grouping of neural responses reveals spatially segregated clusters in prearcuate cortex.

    PubMed

    Kiani, Roozbeh; Cueva, Christopher J; Reppas, John B; Peixoto, Diogo; Ryu, Stephen I; Newsome, William T

    2015-03-18

    A fundamental challenge in studying the frontal lobe is to parcellate this cortex into "natural" functional modules despite the absence of topographic maps, which are so helpful in primary sensory areas. Here we show that unsupervised clustering algorithms, applied to 96-channel array recordings from prearcuate gyrus, reveal spatially segregated subnetworks that remain stable across behavioral contexts. Looking for natural groupings of neurons based on response similarities, we discovered that the recorded area includes at least two spatially segregated subnetworks that differentially represent behavioral choice and reaction time. Importantly, these subnetworks are detectable during different behavioral states and, surprisingly, are defined better by "common noise" than task-evoked responses. Our parcellation process works well on "spontaneous" neural activity, and thus bears strong resemblance to the identification of "resting-state" networks in fMRI data sets. Our results demonstrate a powerful new tool for identifying cortical subnetworks by objective classification of simultaneously recorded electrophysiological activity.

  11. Neural and Behavioral Responses During Self-Evaluative Processes Differ in Youth With and Without Autism

    PubMed Central

    Merchant, Junaid S.; Colich, Natalie L.; Hernandez, Leanna M.; Rudie, Jeff D.; Dapretto, Mirella

    2012-01-01

    This fMRI study investigated neural responses while making appraisals of self and other, across the social and academic domains, in children and adolescents with and without autism spectrum disorders (ASD). Compared to neurotypical youth, those with ASD exhibited hypoactivation of ventromedial prefrontal cortex during self-appraisals. Responses in middle cingulate cortex (MCC) and anterior insula (AI) also distinguished between groups. Stronger activity in MCC and AI during self-appraisals was associated with better social functioning in the ASD group. Although self-appraisals were significantly more positive in the neurotypical group, positivity was unrelated to brain activity in these regions. Together, these results suggest that multiple brain regions support making self-appraisals in neurotypical development, and function atypically in youth with ASD. PMID:22760337

  12. Neural mechanisms of spatial stimulus-response compatibility: the effect of crossed-hand position.

    PubMed

    Matsumoto, Eriko; Misaki, Masaya; Miyauchi, Satoru

    2004-09-01

    Previous psychological experiments have indicated the existence of a visual-proprioceptive interaction in spatial stimulus-response compatibility (SSRC) tasks, but there is little specific information on the neural basis of such interaction in humans. Using functional magnetic resonance imaging (fMRI), we compared the neural activity associated with two different aspects of spatial coding: the coding of the "internal" spatial position of motor-response effectors (i.e., the position of body parts) as obtained through proprioception, and the coding of "external" positions, i.e., the positions of visual stimuli. A 2 x 2 factorial design was used to investigate the spatial compatibility (incompatible versus compatible) between a visual stimulus and hand position (crossed versus uncrossed). The subjects were instructed to respond to stimuli presented to the right or left visual field with either the ipsilateral (compatible condition) or the contralateral hand (incompatible condition). The incompatible condition produced stronger activation in the bilateral superior parietal lobule, inferior parietal lobule, and bilateral superior frontal gyrus than the compatible condition. The crossed-hand condition produced stronger activation in the bilateral precentral gyrus, superior frontal gyrus, superior parietal lobule, and superior temporal gyrus than the uncrossed-hand condition. These results suggest that activity in the frontal-parietal regions is related to two functions: (1) representation of the visual stimulus-motor response spatial configuration in an SSRC task, and (2) integration between external visual and internal proprioceptive sensory information. The activation in the superior temporal gyrus was not affected by the visual stimulus-motor response spatial configuration in an SSRC task; rather, it was affected by the crossed-hand posture. Thus, it seems to be related to representing internal proprioceptive sensory information necessary to carry out motor actions.

  13. Enhancing neural stem cell response to SDF-1α gradients through hyaluronic acid-laminin hydrogels.

    PubMed

    Addington, C P; Heffernan, J M; Millar-Haskell, C S; Tucker, E W; Sirianni, R W; Stabenfeldt, S E

    2015-12-01

    Traumatic brain injury (TBI) initiates an expansive biochemical insult that is largely responsible for the long-term dysfunction associated with TBI; however, current clinical treatments fall short of addressing these underlying sequelae. Pre-clinical investigations have used stem cell transplantation with moderate success, but are plagued by staggeringly low survival and engraftment rates (2-4%). As such, providing cell transplants with the means to better dynamically respond to injury-related signals within the transplant microenvironment may afford improved transplantation survival and engraftment rates. The chemokine stromal cell-derived factor-1α (SDF-1α) is a potent chemotactic signal that is readily present after TBI. In this study, we sought to develop a transplantation vehicle to ultimately enhance the responsiveness of neural transplants to injury-induced SDF-1α. Specifically, we hypothesize that a hyaluronic acid (HA) and laminin (Lm) hydrogel would promote 1. upregulated expression of the SDF-1α receptor CXCR4 in neural progenitor/stem cells (NPSCs) and 2. enhanced NPSC migration in response to SDF-1α gradients. We demonstrated successful development of a HA-Lm hydrogel and utilized standard protein and cellular assays to probe NPSC CXCR4 expression and NPSC chemotactic migration. The findings demonstrated that NPSCs significantly increased CXCR4 expression after 48 h of culture on the HA-Lm gel in a manner critically dependent on both HA and laminin. Moreover, the HA-Lm hydrogel significantly increased NPSC chemotactic migration in response to SDF-1α at 48 h, an effect that was critically dependent on HA, laminin and the SDF-1α gradient. Therefore, this hydrogel serves to 1. prime NPSCs for the injury microenvironment and 2. provide the appropriate infrastructure to support migration into the surrounding tissue, equipping cells with the tools to more effectively respond to the injury microenvironment.

  14. Improved system identification using artificial neural networks and analysis of individual differences in responses of an identified neuron.

    PubMed

    Costalago Meruelo, Alicia; Simpson, David M; Veres, Sandor M; Newland, Philip L

    2016-03-01

    Mathematical modelling is used routinely to understand the coding properties and dynamics of responses of neurons and neural networks. Here we analyse the effectiveness of Artificial Neural Networks (ANNs) as a modelling tool for motor neuron responses. We used ANNs to model the synaptic responses of an identified motor neuron, the fast extensor motor neuron, of the desert locust in response to displacement of a sensory organ, the femoral chordotonal organ, which monitors movements of the tibia relative to the femur of the leg. The aim of the study was threefold: first to determine the potential value of ANNs as tools to model and investigate neural networks, second to understand the generalisation properties of ANNs across individuals and to different input signals and third, to understand individual differences in responses of an identified neuron. A metaheuristic algorithm was developed to design the ANN architectures. The performance of the models generated by the ANNs was compared with those generated through previous mathematical models of the same neuron. The results suggest that ANNs are significantly better than LNL and Wiener models in predicting specific neural responses to Gaussian White Noise, but not significantly different when tested with sinusoidal inputs. They are also able to predict responses of the same neuron in different individuals irrespective of which animal was used to develop the model, although notable differences between some individuals were evident.

  15. Neural activation in the "reward circuit" shows a nonlinear response to facial attractiveness.

    PubMed

    Liang, Xiaoyun; Zebrowitz, Leslie A; Zhang, Yi

    2010-01-01

    Positive behavioral responses to attractive faces have led neuroscientists to investigate underlying neural mechanisms in a "reward circuit" that includes brain regions innervated by dopamine pathways. Using male faces ranging from attractive to extremely unattractive, disfigured ones, this study is the first to demonstrate heightened responses to both rewarding and aversive faces in numerous areas of this putative reward circuit. Parametric analyses employing orthogonal linear and nonlinear regressors revealed positive nonlinear effects in anterior cingulate cortex, lateral orbital frontal cortex (LOFC), striatum (nucleus accumbens, caudate, putamen), and ventral tegmental area, in addition to replicating previously documented linear effects in medial orbital frontal cortex (MOFC) and LOFC and nonlinear effects in amygdala and MOFC. The widespread nonlinear responses are consistent with single cell recordings in animals showing responses to both rewarding and aversive stimuli, and with some human fMRI investigations of non-face stimuli. They indicate that the reward circuit does not process face valence with any simple dissociation of function across structures. Perceiver gender modulated some responses to our male faces: Women showed stronger linear effects, and men showed stronger nonlinear effects, which may have functional implications. Our discovery of nonlinear responses to attractiveness throughout the reward circuit echoes the history of amygdala research: Early work indicated a linear response to threatening stimuli, including faces; later work also revealed a nonlinear response with heightened activation to affectively salient stimuli regardless of valence. The challenge remains to determine how such dual coding influences feelings, such as pleasure and pain, and guides goal-related behavioral responses, such as approach and avoidance.

  16. EEG neural oscillatory dynamics reveal semantic and response conflict at difference levels of conflict awareness.

    PubMed

    Jiang, Jun; Zhang, Qinglin; Van Gaal, Simon

    2015-07-14

    Although previous work has shown that conflict can be detected in the absence of awareness, it is unknown how different sources of conflict (i.e., semantic, response) are processed in the human brain and whether these processes are differently modulated by conflict awareness. To explore this issue, we extracted oscillatory power dynamics from electroencephalographic (EEG) data recorded while human participants performed a modified version of the Stroop task. Crucially, in this task conflict awareness was manipulated by masking a conflict-inducing color word preceding a color patch target. We isolated semantic from response conflict by introducing four color words/patches, of which two were matched to the same response. We observed that both semantic as well as response conflict were associated with mid-frontal theta-band and parietal alpha-band power modulations, irrespective of the level of conflict awareness (high vs. low), although awareness of conflict increased these conflict-related power dynamics. These results show that both semantic and response conflict can be processed in the human brain and suggest that the neural oscillatory mechanisms in EEG reflect mainly "domain general" conflict processing mechanisms, instead of conflict source specific effects.

  17. Neuroticism modulates the effects of intranasal vasopressin treatment on the neural response to positive and negative social interactions.

    PubMed

    Feng, Chunliang; DeMarco, Ashley C; Haroon, Ebrahim; Rilling, James K

    2015-07-01

    Neuroticism is a fundamental personality trait associated with proneness to feel negative affect. Here we ask how Neuroticism influences the neural response to positive and negative social interactions and how Neuroticism modulates the effect of intranasal oxytocin (OT) and vasopressin (AVP) on the neural response to social interactions. In a double-blind, placebo-controlled study, 153 male participants were randomized to receive 24 IU intranasal OT, 20 IU AVP or placebo. Afterwards, they were imaged with fMRI while playing an iterated Prisoner's Dilemma Game. On a different day, subjects completed the NEO personality inventory to measure Neuroticism. Neuroticism was positively correlated with the neural response to negative social interactions in the anterior cingulate cortex/medial prefrontal cortex and with the neural response to positive social interactions in the insula, indicating that Neuroticism modulates neuropsychological processing of both negative and positive social interactions. Neuroticism did not modulate the effect of intranasal OT treatment on the neural response to either positive or negative social interactions. On the other hand, AVP treatment significantly interacted with Neuroticism to modulate the BOLD response to both positive and negative social interactions. Specifically, AVP increased anterior cingulate cortex/medial prefrontal cortex and lateral temporal lobe responses to negative social interactions to a greater extent in participants scoring high rather than low on Neuroticism. AVP also increased the insula response to positive social interactions to a greater extent in participants scoring high rather than low on Neuroticism. These results imply that AVP may increase emotion regulation in response to negative social interactions and the salience of positive social interactions to a greater extent in individuals high compared to low in Neuroticism. The current findings urge caution against uniform clinical application of nonapeptides

  18. Candy and the brain: neural response to candy gains and losses.

    PubMed

    Luking, Katherine R; Barch, Deanna M

    2013-09-01

    Incentive processing is a critical component of a host of cognitive processes, including attention, motivation, and learning. Neuroimaging studies have clarified the neural systems underlying processing of primary and secondary rewards in adults. However, current reward paradigms have hindered comparisons across these reward types as well as between age groups. To address methodological issues regarding the timing of incentive delivery (during scan vs. postscan) and the age-appropriateness of the incentive type, we utilized fMRI and a modified version of a card-guessing game (CGG), in which candy pieces delivered postscan served as the reinforcer, to investigate neural responses to incentives. Healthy young adults 22-26 years of age won and lost large and small amounts of candy on the basis of their ability to guess the number on a mystery card. BOLD activity was compared following candy gain (large/small), loss (large/small), and neutral feedback. During candy gains, adults recruited regions typically involved in response to monetary and other rewards, such as the caudate, putamen, and orbitofrontal cortex. During losses, they displayed greater deactivation in the hippocampus than in response to neutral and gain feedback. Additionally, individual-difference analyses suggested a negative relationship between reward sensitivity (assessed by the Behavioral Inhibition/Behavioral Activation Scales) and the difference between high- and low-magnitude losses in the caudate and lateral orbitofrontal cortex. Also within the striatum, greater punishment sensitivity was positively related to the difference in activity following high as compared to low gains. Overall, these results show strong overlap with those from previous monetary versions of the CGG and provide a baseline for future work with developmental populations.

  19. Predicting Response to Neoadjuvant Chemotherapy with PET Imaging Using Convolutional Neural Networks

    PubMed Central

    Ypsilantis, Petros-Pavlos; Siddique, Musib; Sohn, Hyon-Mok; Davies, Andrew; Cook, Gary; Goh, Vicky; Montana, Giovanni

    2015-01-01

    Imaging of cancer with 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) has become a standard component of diagnosis and staging in oncology, and is becoming more important as a quantitative monitor of individual response to therapy. In this article we investigate the challenging problem of predicting a patient’s response to neoadjuvant chemotherapy from a single 18F-FDG PET scan taken prior to treatment. We take a “radiomics” approach whereby a large amount of quantitative features is automatically extracted from pretherapy PET images in order to build a comprehensive quantification of the tumor phenotype. While the dominant methodology relies on hand-crafted texture features, we explore the potential of automatically learning low- to high-level features directly from PET scans. We report on a study that compares the performance of two competing radiomics strategies: an approach based on state-of-the-art statistical classifiers using over 100 quantitative imaging descriptors, including texture features as well as standardized uptake values, and a convolutional neural network, 3S-CNN, trained directly from PET scans by taking sets of adjacent intra-tumor slices. Our experimental results, based on a sample of 107 patients with esophageal cancer, provide initial evidence that convolutional neural networks have the potential to extract PET imaging representations that are highly predictive of response to therapy. On this dataset, 3S-CNN achieves an average 80.7% sensitivity and 81.6% specificity in predicting non-responders, and outperforms other competing predictive models. PMID:26355298

  20. Structure-response relationship in electrospray ionization-mass spectrometry of sartans by artificial neural networks.

    PubMed

    Golubović, Jelena; Birkemeyer, Claudia; Protić, Ana; Otašević, Biljana; Zečević, Mira

    2016-03-18

    Quantitative structure-property relationship (QSPR) methods are based on the hypothesis that changes in the molecular structure are reflected in changes in the observed property of the molecule. Artificial neural network is a technique of data analysis, which sets out to emulate the human brain's way of working. For the first time a quantitative structure-response relationship in electrospray ionization-mass spectrometry (ESI-MS) by means of artificial neural networks (ANN) on the group of angiotensin II receptor antagonists--sartans has been established. The investigated descriptors correspond to different properties of the analytes: polarity (logP), ionizability (pKa), surface area (solvent excluded volume) and number of proton acceptors. The influence of the instrumental parameters: methanol content in mobile phase, mobile phase pH and flow rate was also examined. Best performance showed a multilayer perceptron network with the architecture 6-3-3-1, trained with backpropagation algorithm. It showed high prediction ability on the previously unseen (test) data set with a coefficient of determination of 0.994. High prediction ability of the model would enable prediction of ESI-MS responsiveness under different conditions. This is particularly important in the method development phase. Also, prediction of responsiveness can be important in case of gradient-elution LC-MS and LC-MS/MS methods in which instrumental conditions are varied during time. Polarity, chargeability and surface area all appeared to be crucial for electrospray ionization whereby signal intensity appeared to be the result of a simultaneous influence of the molecular descriptors and their interactions. Percentage of organic phase in the mobile phase showed a positive, while flow rate showed a negative impact on signal intensity.

  1. Neural and vascular variability and the fMRI-BOLD response in normal aging.

    PubMed

    Kannurpatti, Sridhar S; Motes, Michael A; Rypma, Bart; Biswal, Bharat B

    2010-05-01

    Neural, vascular and structural variables contributing to the blood oxygen level-dependent (BOLD) signal response variability were investigated in younger and older humans. Twelve younger healthy human subjects (six male and six female; mean age: 24 years; range: 19-27 years) and 12 older healthy subjects (five male and seven female; mean age: 58 years; range: 55-71 years) with no history of head trauma and neurological disease were scanned. Functional magnetic resonance imaging measurements using the BOLD contrast were made when participants performed a motor, cognitive or a breath hold (BH) task. Activation volume and the BOLD response amplitude were estimated for the younger and older at both group and subject levels. Mean activation volume was reduced by 45%, 40% and 38% in the elderly group during the motor, cognitive and BH tasks, respectively, compared to the younger. Reduction in activation volume was substantially higher compared to the reduction in the gray matter volume of 14% in the older compared to the younger. A significantly larger variability in the intersubject BOLD signal change occurred during the motor task, compared to the cognitive task. BH-induced BOLD signal change between subjects was significantly less-variable in the motor task-activated areas in the younger compared to older whereas such a difference between age groups was not observed during the cognitive task. Hemodynamic scaling using the BH signal substantially reduced the BOLD signal variability during the motor task compared to the cognitive task. The results indicate that the origin of the BOLD signal variability between subjects was predominantly vascular during the motor task while being principally a consequence of neural variability during the cognitive task. Thus, in addition to gray matter differences, the type of task performed can have different vascular variability weighting that can influence age-related differences in brain functional response.

  2. Predicting Response to Neoadjuvant Chemotherapy with PET Imaging Using Convolutional Neural Networks.

    PubMed

    Ypsilantis, Petros-Pavlos; Siddique, Musib; Sohn, Hyon-Mok; Davies, Andrew; Cook, Gary; Goh, Vicky; Montana, Giovanni

    2015-01-01

    Imaging of cancer with 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) has become a standard component of diagnosis and staging in oncology, and is becoming more important as a quantitative monitor of individual response to therapy. In this article we investigate the challenging problem of predicting a patient's response to neoadjuvant chemotherapy from a single 18F-FDG PET scan taken prior to treatment. We take a "radiomics" approach whereby a large amount of quantitative features is automatically extracted from pretherapy PET images in order to build a comprehensive quantification of the tumor phenotype. While the dominant methodology relies on hand-crafted texture features, we explore the potential of automatically learning low- to high-level features directly from PET scans. We report on a study that compares the performance of two competing radiomics strategies: an approach based on state-of-the-art statistical classifiers using over 100 quantitative imaging descriptors, including texture features as well as standardized uptake values, and a convolutional neural network, 3S-CNN, trained directly from PET scans by taking sets of adjacent intra-tumor slices. Our experimental results, based on a sample of 107 patients with esophageal cancer, provide initial evidence that convolutional neural networks have the potential to extract PET imaging representations that are highly predictive of response to therapy. On this dataset, 3S-CNN achieves an average 80.7% sensitivity and 81.6% specificity in predicting non-responders, and outperforms other competing predictive models.

  3. The effect of surface wave propagation on neural responses to vibration in primate glabrous skin.

    PubMed

    Manfredi, Louise R; Baker, Andrew T; Elias, Damian O; Dammann, John F; Zielinski, Mark C; Polashock, Vicky S; Bensmaia, Sliman J

    2012-01-01

    Because tactile perception relies on the response of large populations of receptors distributed across the skin, we seek to characterize how a mechanical deformation of the skin at one location affects the skin at another. To this end, we introduce a novel non-contact method to characterize the surface waves produced in the skin under a variety of stimulation conditions. Specifically, we deliver vibrations to the fingertip using a vibratory actuator and measure, using a laser Doppler vibrometer, the surface waves at different distances from the locus of stimulation. First, we show that a vibration applied to the fingertip travels at least the length of the finger and that the rate at which it decays is dependent on stimulus frequency. Furthermore, the resonant frequency of the skin matches the frequency at which a subpopulation of afferents, namely Pacinian afferents, is most sensitive. We show that this skin resonance can lead to a two-fold increase in the strength of the response of a simulated afferent population. Second, the rate at which vibrations propagate across the skin is dependent on the stimulus frequency and plateaus at 7 m/s. The resulting delay in neural activation across locations does not substantially blur the temporal patterning in simulated populations of afferents for frequencies less than 200 Hz, which has important implications about how vibratory frequency is encoded in the responses of somatosensory neurons. Third, we show that, despite the dependence of decay rate and propagation speed on frequency, the waveform of a complex vibration is well preserved as it travels across the skin. Our results suggest, then, that the propagation of surface waves promotes the encoding of spectrally complex vibrations as the entire neural population is exposed to essentially the same stimulus. We also discuss the implications of our results for biomechanical models of the skin.

  4. Abnormal response of the proliferation and differentiation of growth plate chondrocytes to melatonin in adolescent idiopathic scoliosis.

    PubMed

    Wang, William Wei-Jun; Man, Gene Chi-Wai; Wong, Jack Ho; Ng, Tzi-Bun; Lee, Kwong-Man; Ng, Bobby Kin-Wah; Yeung, Hiu-Yan; Qiu, Yong; Cheng, Jack Chun-Yiu

    2014-09-25

    Abnormalities in the melatonin signaling pathway and the involvement of melatonin receptor MT2 have been reported in patients with adolescent idiopathic scoliosis (AIS). Whether these abnormalities were involved in the systemic abnormal skeletal growth in AIS during the peripubertal period remain unknown. In this cross-sectional case-control study, growth plate chondrocytes (GPCs) were cultured from twenty AIS and ten normal control subjects. Although the MT2 receptor was identified in GPCs from both AIS and controls, its mRNA expression was significantly lower in AIS patients than the controls. GPCs were cultured in the presence of either the vehicle or various concentrations of melatonin, with or without the selective MT2 melatonin receptor antagonist 4-P-PDOT (10 µM). Then the cell viability and the mRNA expression of collagen type X (COLX) and alkaline phosphatase (ALP) were assessed by MTT and qPCR, respectively. In the control GPCs, melatonin at the concentrations of 1, 100 nM and 10 µM significantly reduced the population of viable cells, and the mRNA level of COLX and ALP compared to the vehicle. Similar changes were not observed in the presence of 4-P-PDOT. Further, neither proliferation nor differentiation of GPCs from AIS patients was affected by the melatonin treatment. These findings support the presence of a functional abnormality of the melatonin signaling pathway in AIS GPCs, which might be associated with the abnormal endochondral ossification in AIS patients.

  5. Response to an abnormal ovarian cancer-screening test result: test of the social cognitive processing and cognitive social health information processing models.

    PubMed

    Andrykowski, Michael A; Pavlik, Edward J

    2011-04-01

    All cancer screening tests produce a proportion of abnormal results requiring follow up. Consequently, the cancer-screening setting is a natural laboratory for examining psychological and behavioural response to a threatening health-related event. This study tested hypotheses derived from the social cognitive processing and cognitive-social health information processing models in trying to understand response to an abnormal ovarian cancer (OC) screening test result. Women (n = 278) receiving an abnormal screening test result a mean of 7 weeks earlier were assessed prior to a repeat screening test intended to clarify their previous abnormal result. Measures of disposition (optimism, informational coping style), social environment (social support and constraint), emotional processing, distress, and benefit finding were obtained. Regression analyses indicated greater distress was associated with greater social constraint and emotional processing and a monitoring coping style in women with a family history of OC. Distress was unrelated to social support. Greater benefit finding was associated with both greater social constraint and support and greater distress. The primacy of social constraint in accounting for both benefit finding and distress was noteworthy and warrants further research on the role of social constraint in adaptation to stressful events.

  6. METHYLMERCURY INDUCED TOXICOGENOMIC RESPONSE IN C57 AND SWV MOUSE EMBRYOS UNDERGOING NEURAL TUBE CLOSURE

    PubMed Central

    Robinson, Joshua F.; Griffith, William C.; Yu, Xiaozhong; Hong, Sungwoo; Kim, Euvin; Faustman, Elaine M.

    2010-01-01

    Methylmercury (MeHg) is a developmental neurotoxicant and teratogen and is hypothesized to perturb a wide range of biological processes, like other metals including arsenic (As) and cadmium (Cd). Common inbred mouse strains including C57 (sensitive) and SWV (resistant) display differences in sensitivity to metals such as As and Cd when exposed during neurulation. In this study, we investigated the impact of MeHg on neurulation, assessing for potential differences in sensitivity and associated toxicogenomic response in C57 and SWV mouse embryos. Parallel with morphological assessments of neural tube closure, we evaluated quantitative differences in MeHg-induced alterations in expression between strains at the gene level and within gene-enriched biological processes. Specifically, we observed differing sensitivities to MeHg-induced impacts on neural tube closure between C57 and SWV embryos in a time-dependent manner. These observations correlated with greater impact on the expression of genes associated with development and environmental stress-related pathways in the C57 compared to the SWV. Additional developmental parameters (e.g. mortality, growth effects) evaluated showed mixed significant effects across the two strains and did not support observations of differential sensitivity to MeHg. This study provides potential insights into MeHg-induced mechanisms of developmental toxicity, alterations associated with increased MeHg sensitivity and common biological processes affected by metals in embryos undergoing neurulation. PMID:20493249

  7. Neural response in obsessive-compulsive washers depends on individual fit of triggers

    PubMed Central

    Baioui, Ali; Pilgramm, Juliane; Merz, Christian J.; Walter, Bertram; Vaitl, Dieter; Stark, Rudolf

    2013-01-01

    Background: Patients with obsessive-compulsive disorder (OCD) have highly idiosyncratic triggers. To fully understand which role this idiosyncrasy plays in the neurobiological mechanisms behind OCD, it is necessary to elucidate the impact of individualization regarding the applied investigation methods. This functional magnetic resonance imaging (fMRI) study explores the neural correlates of contamination/washing-related OCD with a highly individualized symptom provocation paradigm. Additionally, it is the first study to directly compare individualized and standardized symptom provocation. Methods: Nineteen patients with washing compulsions created individual OCD hierarchies, which later served as instructions to photograph their own individualized stimulus sets. The patients and 19 case-by-case matched healthy controls participated in a symptom provocation fMRI experiment with individualized and standardized stimulus sets created for each patient. Results: OCD patients compared to healthy controls displayed stronger activation in the basal ganglia (nucleus accumbens, nucleus caudatus, pallidum) for individualized symptom provocation. Using standardized symptom provocation, this group comparison led to stronger activation in the nucleus caudatus. The direct comparison of between-group effects for both symptom provocation approaches revealed stronger activation of the orbitofronto-striatal network for individualized symptom provocation. Conclusions: The present study provides insight into the differential impact of individualized and standardized symptom provocation on the orbitofronto-striatal network of OCD washers. Behavioral and neural responses imply a higher symptom-specificity of individualized symptom provocation. PMID:23630478

  8. Structured chaos shapes spike-response noise entropy in balanced neural networks.

    PubMed

    Lajoie, Guillaume; Thivierge, Jean-Philippe; Shea-Brown, Eric

    2014-01-01

    Large networks of sparsely coupled, excitatory and inhibitory cells occur throughout the brain. For many models of these networks, a striking feature is that their dynamics are chaotic and thus, are sensitive to small perturbations. How does this chaos manifest in the neural code? Specifically, how variable are the spike patterns that such a network produces in response to an input signal? To answer this, we derive a bound for a general measure of variability-spike-train entropy. This leads to important insights on the variability of multi-cell spike pattern distributions in large recurrent networks of spiking neurons responding to fluctuating inputs. The analysis is based on results from random dynamical systems theory and is complemented by detailed numerical simulations. We find that the spike pattern entropy is an order of magnitude lower than what would be extrapolated from single cells. This holds despite the fact that network coupling becomes vanishingly sparse as network size grows-a phenomenon that depends on "extensive chaos," as previously discovered for balanced networks without stimulus drive. Moreover, we show how spike pattern entropy is controlled by temporal features of the inputs. Our findings provide insight into how neural networks may encode stimuli in the presence of inherently chaotic dynamics.

  9. Efficient Simulation of Wing Modal Response: Application of 2nd Order Shape Sensitivities and Neural Networks

    NASA Technical Reports Server (NTRS)

    Kapania, Rakesh K.; Liu, Youhua

    2000-01-01

    At the preliminary design stage of a wing structure, an efficient simulation, one needing little computation but yielding adequately accurate results for various response quantities, is essential in the search of optimal design in a vast design space. In the present paper, methods of using sensitivities up to 2nd order, and direct application of neural networks are explored. The example problem is how to decide the natural frequencies of a wing given the shape variables of the structure. It is shown that when sensitivities cannot be obtained analytically, the finite difference approach is usually more reliable than a semi-analytical approach provided an appropriate step size is used. The use of second order sensitivities is proved of being able to yield much better results than the case where only the first order sensitivities are used. When neural networks are trained to relate the wing natural frequencies to the shape variables, a negligible computation effort is needed to accurately determine the natural frequencies of a new design.

  10. Neural Network Based Response Prediction of rTMS in Major Depressive Disorder Using QEEG Cordance

    PubMed Central

    Ozekes, Serhat; Gultekin, Selahattin; Tarhan, Nevzat; Hizli Sayar, Gokben; Bayram, Ali

    2015-01-01

    Objective The combination of repetitive transcranial magnetic stimulation (rTMS), a non-pharmacological form of therapy for treating major depressive disorder (MDD), and electroencephalogram (EEG) is a valuable tool for investigating the functional connectivity in the brain. This study aims to explore whether pre-treating frontal quantitative EEG (QEEG) cordance is associated with response to rTMS treatment among MDD patients by using an artificial intelligence approach, artificial neural network (ANN). Methods The artificial neural network using pre-treatment cordance of frontal QEEG classification was carried out to identify responder or non-responder to rTMS treatment among 55 MDD subjects. The classification performance was evaluated using k-fold cross-validation. Results The ANN classification identified responders to rTMS treatment with a sensitivity of 93.33%, and its overall accuracy reached to 89.09%. Area under Receiver Operating Characteristic (ROC) curve (AUC) value for responder detection using 6, 8 and 10 fold cross validation were 0.917, 0.823 and 0.894 respectively. Conclusion Potential utility of ANN approach method can be used as a clinical tool in administering rTMS therapy to a targeted group of subjects suffering from MDD. This methodology is more potentially useful to the clinician as prediction is possible using EEG data collected before this treatment process is initiated. It is worth using feature selection algorithms to raise the sensitivity and accuracy values. PMID:25670947

  11. A response surface model predicting the in vivo insertion behavior of micromachined neural implants

    NASA Astrophysics Data System (ADS)

    Andrei, A.; Welkenhuysen, M.; Nuttin, B.; Eberle, W.

    2012-02-01

    The mechanical damage caused by the insertion of a foreign body into living tissue is inevitable, especially when a considerable stiffness mismatch is present, as in the case of micromachined neural implants and brain tissue. However, the response surface model based on a central composite experimental design described in this study showed that for particular configurations of the implant tip angle, width, thickness or insertion speed, some of these factors could be safely increased without causing an unwanted significant force or tissue dimpling increase. The model covers chisel tip angles between 10° and 50°, implant widths within the 200-400 µm range and thicknesses between 50 and 150 µm. The insertion speed has been varied from 10 up to 100 µm s-1 to reach a final insertion depth of 6 mm. Coating the implant with parylene C proved to be beneficial in reducing the friction between the implant and the surrounding tissue. Successfully validated for a particular implant geometry, this model could be used as an insertion behavior prediction tool for the design optimization of future neural implants.

  12. Neural response to reward anticipation under risk is nonlinear in probabilities.

    PubMed

    Hsu, Ming; Krajbich, Ian; Zhao, Chen; Camerer, Colin F

    2009-02-18

    A widely observed phenomenon in decision making under risk is the apparent overweighting of unlikely events and the underweighting of nearly certain events. This violates standard assumptions in expected utility theory, which requires that expected utility be linear (objective) in probabilities. Models such as prospect theory have relaxed this assumption and introduced the notion of a "probability weighting function," which captures the key properties found in experimental data. This study reports functional magnetic resonance imaging (fMRI) data that neural response to expected reward is nonlinear in probabilities. Specifically, we found that activity in the striatum during valuation of monetary gambles are nonlinear in probabilities in the pattern predicted by prospect theory, suggesting that probability distortion is reflected at the level of the reward encoding process. The degree of nonlinearity reflected in individual subjects' decisions is also correlated with striatal activity across subjects. Our results shed light on the neural mechanisms of reward processing, and have implications for future neuroscientific studies of decision making involving extreme tails of the distribution, where probability weighting provides an explanation for commonly observed behavioral anomalies.

  13. How specific is specific phobia? Different neural response patterns in two subtypes of specific phobia.

    PubMed

    Lueken, Ulrike; Kruschwitz, Johann Daniel; Muehlhan, Markus; Siegert, Jens; Hoyer, Jürgen; Wittchen, Hans-Ulrich

    2011-05-01

    Specific phobia of the animal subtype has been employed as a model disorder exploring the neurocircuitry of anxiety disorders, but evidence is lacking whether the detected neural response pattern accounts for all animal subtypes, nor across other phobia subtypes. The present study aimed at directly comparing two subtypes of specific phobia: snake phobia (SP) representing the animal, and dental phobia (DP) representing the blood-injection-injury subtype. Using functional magnetic resonance imaging (fMRI), brain activation and skin conductance was measured during phobogenic video stimulation in 12 DP, 12 SP, and 17 healthy controls. For SP, the previously described activation of fear circuitry structures encompassing the insula, anterior cingulate cortex and thalamus could be replicated and was furthermore associated with autonomic arousal. In contrast, DP showed circumscribed activation of the prefrontal and orbitofrontal cortex (PFC/OFC) when directly compared to SP, being dissociated from autonomic arousal. Results provide preliminary evidence for the idea that snake and dental phobia are characterized by distinct underlying neural systems during sustained emotional processing with evaluation processes in DP being controlled by orbitofrontal areas, whereas phobogenic reactions in SP are primarily guided by limbic and paralimbic structures. Findings support the current diagnostic classification conventions, separating distinct subtypes in DSM-IV-TR. They highlight that caution might be warranted though for generalizing findings derived from animal phobia to other phobic and anxiety disorders. If replicated, results could contribute to a better understanding of underlying neurobiological mechanisms of specific phobia and their respective classification.

  14. The Neural Crest in Cardiac Congenital Anomalies

    PubMed Central

    Keyte, Anna; Hutson, Mary Redmond

    2012-01-01

    This review discusses the function of neural crest as they relate to cardiovascular defects. The cardiac neural crest cells are a subpopulation of cranial neural crest discovered nearly 30 years ago by ablation of premigratory neural crest. The cardiac neural crest cells are necessary for normal cardiovascular development. We begin with a description of the crest cells in normal development, including their function in remodeling the pharyngeal arch arteries, outflow tract septation, valvulogenesis, and development of the cardiac conduction system. The cells are also responsible for modulating signaling in the caudal pharynx, including the second heart field. Many of the molecular pathways that are known to influence specification, migration, patterning and final targeting of the cardiac neural crest cells are reviewed. The cardiac neural crest cells play a critical role in the pathogenesis of various human cardiocraniofacial syndromes such as DiGeorge, Velocardiofacial, CHARGE, Fetal Alcohol, Alagille, LEOPARD, and Noonan syndromes, as well as Retinoic Acid Embryopathy. The loss of neural crest cells or their dysfunction may not always directly cause abnormal cardiovascular development, but are involved secondarily because crest cells represent a major component in the complex tissue interactions in the head, pharynx and outflow tract. Thus many of the human syndromes linking defects in the heart, face and brain can be better understood when considered within the context of a single cardiocraniofacial developmental module with the neural crest being a key cell type that interconnects the regions. PMID:22595346

  15. Hyaluronic acid-laminin hydrogels increase neural stem cell transplant retention and migratory response to SDF-1α.

    PubMed

    Addington, C P; Dharmawaj, S; Heffernan, J M; Sirianni, R W; Stabenfeldt, S E

    2016-09-17

    The chemokine SDF-1α plays a critical role in mediating stem cell response to injury and disease and has specifically been shown to mobilize neural progenitor/stem cells (NPSCs) towards sites of neural injury. Current neural transplant paradigms within the brain suffer from low rates of retention and engraftment after injury. Therefore, increasing transplant sensitivity to injury-induced SDF-1α represents a method for increasing neural transplant efficacy. Previously, we have reported on a hyaluronic acid-laminin based hydrogel (HA-Lm gel) that increases NPSC expression of SDF-1α receptor, CXCR4, and subsequently, NPSC chemotactic migration towards a source of SDF-1α in vitro. The study presented here investigates the capacity of the HA-Lm gel to promote NPSC response to exogenous SDF-1α in vivo. We observed the HA-Lm gel to significantly increase NPSC transplant retention and migration in response to SDF-1α in a manner critically dependent on signaling via the SDF-1α-CXCR4 axis. This work lays the foundation for development of a more effective cell therapy for neural injury, but also has broader implications in the fields of tissue engineering and regenerative medicine given the essential roles of SDF-1α across injury and disease states.

  16. Modeling forest ecosystem responses to elevated carbon dioxide and ozone using artificial neural networks.

    PubMed

    Larsen, Peter E; Cseke, Leland J; Miller, R Michael; Collart, Frank R

    2014-10-21

    Rising atmospheric levels of carbon dioxide and ozone will impact productivity and carbon sequestration in forest ecosystems. The scale of this process and the potential economic consequences provide an incentive for the development of models to predict the types and rates of ecosystem responses and feedbacks that result from and influence of climate change. In this paper, we use phenotypic and molecular data derived from the Aspen Free Air CO2 Enrichment site (Aspen-FACE) to evaluate modeling approaches for ecosystem responses to changing conditions. At FACE, it was observed that different aspen clones exhibit clone-specific responses to elevated atmospheric levels of carbon dioxide and ozone. To identify the molecular basis for these observations, we used artificial neural networks (ANN) to examine above and below-ground community phenotype responses to elevated carbon dioxide, elevated ozone and gene expression profiles. The aspen community models generated using this approach identified specific genes and subnetworks of genes associated with variable sensitivities for aspen clones. The ANN model also predicts specific co-regulated gene clusters associated with differential sensitivity to elevated carbon dioxide and ozone in aspen species. The results suggest ANN is an effective approach to predict relevant gene expression changes resulting from environmental perturbation and provides useful information for the rational design of future biological experiments.

  17. Empathic neural responses are modulated by the perceived fairness of others

    PubMed Central

    Singer, Tania; Seymour, Ben; O'Doherty, John P.; Stephan, Klaas E.; Dolan, Raymond J.; Frith, Chris D.

    2009-01-01

    The neural processes underlying empathy are a subject of intense interest within the social neurosciences1-3. However, very little is known about how brain empathic responses are modulated by the affective link between individuals. We show here that empathic responses are modulated by learned preferences, a result consistent with economic models of social preferences4-7. We engaged male and female volunteers in an economic game, in which two confederates played fairly or unfairly, and then measured brain activity with functional magnetic resonance imaging while these same volunteers observed the confederates receiving pain. Both sexes exhibited empathy-related activation in pain-related brain areas (fronto-insular and anterior cingulate cortices) towards fair players. However, these empathy-related responses were significantly reduced in males when observing an unfair person receiving pain. This effect was accompanied by increased activation in reward-related areas, correlated with an expressed desire for revenge. We conclude that in men (at least) empathic responses are shaped by valuation of other people's social behaviour, such that they empathize with fair opponents while favouring the physical punishment of unfair opponents, a finding that echoes recent evidence for altruistic punishment. PMID:16421576

  18. Relief as a reward: hedonic and neural responses to safety from pain.

    PubMed

    Leknes, Siri; Lee, Michael; Berna, Chantal; Andersson, Jesper; Tracey, Irene

    2011-04-07

    Relief fits the definition of a reward. Unlike other reward types the pleasantness of relief depends on the violation of a negative expectation, yet this has not been investigated using neuroimaging approaches. We hypothesized that the degree of negative expectation depends on state (dread) and trait (pessimism) sensitivity. Of the brain regions that are involved in mediating pleasure, the nucleus accumbens also signals unexpected reward and positive prediction error. We hypothesized that accumbens activity reflects the level of negative expectation and subsequent pleasant relief. Using fMRI and two purpose-made tasks, we compared hedonic and BOLD responses to relief with responses during an appetitive reward task in 18 healthy volunteers. We expected some similarities in task responses, reflecting common neural substrates implicated across reward types. However, we also hypothesized that relief responses would differ from appetitive rewards in the nucleus accumbens, since only relief pleasantness depends on negative expectations. The results confirmed these hypotheses. Relief and appetitive reward task activity converged in the ventromedial prefrontal cortex, which also correlated with appetitive reward pleasantness ratings. In contrast, dread and pessimism scores correlated with relief but not with appetitive reward hedonics. Moreover, only relief pleasantness covaried with accumbens activation. Importantly, the accumbens signal appeared to specifically reflect individual differences in anticipation of the adverse event (dread, pessimism) but was uncorrelated to appetitive reward hedonics. In conclusion, relief differs from appetitive rewards due to its reliance on negative expectations, the violation of which is reflected in relief-related accumbens activation.

  19. Relief as a Reward: Hedonic and Neural Responses to Safety from Pain

    PubMed Central

    Leknes, Siri; Lee, Michael; Berna, Chantal; Andersson, Jesper; Tracey, Irene

    2011-01-01

    Relief fits the definition of a reward. Unlike other reward types the pleasantness of relief depends on the violation of a negative expectation, yet this has not been investigated using neuroimaging approaches. We hypothesized that the degree of negative expectation depends on state (dread) and trait (pessimism) sensitivity. Of the brain regions that are involved in mediating pleasure, the nucleus accumbens also signals unexpected reward and positive prediction error. We hypothesized that accumbens activity reflects the level of negative expectation and subsequent pleasant relief. Using fMRI and two purpose-made tasks, we compared hedonic and BOLD responses to relief with responses during an appetitive reward task in 18 healthy volunteers. We expected some similarities in task responses, reflecting common neural substrates implicated across reward types. However, we also hypothesized that relief responses would differ from appetitive rewards in the nucleus accumbens, since only relief pleasantness depends on negative expectations. The results confirmed these hypotheses. Relief and appetitive reward task activity converged in the ventromedial prefrontal cortex, which also correlated with appetitive reward pleasantness ratings. In contrast, dread and pessimism scores correlated with relief but not with appetitive reward hedonics. Moreover, only relief pleasantness covaried with accumbens activation. Importantly, the accumbens signal appeared to specifically reflect individual differences in anticipation of the adverse event (dread, pessimism) but was uncorrelated to appetitive reward hedonics. In conclusion, relief differs from appetitive rewards due to its reliance on negative expectations, the violation of which is reflected in relief-related accumbens activation. PMID:21490964

  20. Longitudinal Analysis of the Absence of Intraoperative Neural Response Telemetry in Children using Cochlear Implants.

    PubMed

    Moura, Amanda Christina Gomes de; Goffi-Gomez, Maria Valéria Schmidt; Couto, Maria Ines Vieira; Brito, Rubens; Tsuji, Robinson Koji; Befi-Lopes, Debora Maria; Matas, Carla Gentile; Bento, Ricardo Ferreira

    2014-10-01

    Introduction Currently the cochlear implant allows access to sounds in individuals with profound hearing loss. The objective methods used to verify the integrity of the cochlear device and the electrophysiologic response of users have noted these improvements. Objective To establish whether the evoked compound action potential of the auditory nerve can appear after electrical stimulation when it is absent intraoperatively. Methods The clinical records of children implanted with the Nucleus Freedom (Cochlear Ltd., Australia) (CI24RE) cochlear implant between January 2009 and January 2010 with at least 6 months of use were evaluated. The neural response telemetry (NRT) thresholds of electrodes 1, 6, 11, 16, and 22 during surgery and after at least 3 months of implant use were analyzed and correlated with etiology, length of auditory deprivation, and chronological age. These data were compared between a group of children exhibiting responses in all of the tested electrodes and a group of children who had at least one absent response. Results The sample was composed of clinical records of 51 children. From these, 21% (11) showed no NRT in at least one of the tested electrodes. After an average of 4.9 months of stimulation, the number of individuals exhibiting absent responses decreased from 21 to 11% (n = 6). Conclusion It is feasible that absent responses present after a period of electrical stimulation. In our sample, 45% (n = 5) of the patients with intraoperative absence exhibited a positive response after an average of 4.9 months of continued electrical stimulation.

  1. Heath monitoring of a glass transfer robot in the mass production line of liquid crystal display using abnormal operating sounds based on wavelet packet transform and artificial neural network

    NASA Astrophysics Data System (ADS)

    Kim, Eui-Youl; Lee, Young-Joon; Lee, Sang-Kwon

    2012-07-01

    This paper presents the fault detect method of a moving transfer robot in the mass production line of liquid crystal display (LCD) manufacturers based on the wavelet packet transform (WPT) for feature extraction and the artificial neural network (ANN) for fault classification. Most of fault detection methods in a mechanical system have been researched based on the vibration signal. Unlike the existing methodologies, this study aims to minimize the uncertainty of a field engineer's decision making process for determining whether a fault is present or not based on the human auditory perception by developing a fault diagnosis system that uses the abnormal operating sound radiated from a moving transfer robot as a source signal. Abnormal operating sound radiated from a moving transfer robot has been used for this work instead of other source signals such as vibration, acoustic emission, electrical signal, etc. Its advantage as a source signal makes it possible to monitor the status of multiple faults by using only a microphone despite a relatively low sensitivity. In the application of ANN, since it is important to minimize the error of trained ANN in terms of the accuracy of fault diagnosis logic, in the paper, the number of input and target data samples was increased through a regeneration process based on statistical properties, and then the uncorrelated nodes in the input vector were also removed to improve the orthogonality of the input vector based on the entropy based feature selection method. Consequently, it can be concluded that the abnormal operating sound is sufficiently useful as a source signal for the fault diagnosis of mechanical components as well as other source signals.

  2. Identification of a retinoic acid-responsive neural enhancer in the Ciona intestinalis Hox1 gene.

    PubMed

    Kanda, Miyuki; Ikeda, Taku; Fujiwara, Shigeki

    2013-02-01

    The Hox1 gene in the urochordate ascidian Ciona intestinalis (Ci-Hox1) is expressed in the nerve cord and epidermis. We identified a nerve cord enhancer in the second intron of Ci-Hox1, and demonstrated that retinoic acid (RA) plays a major role in activating this enhancer. The enhancer contained a putative retinoic acid-response element (RARE). Mutation of the RARE in the Ci-Hox1 nerve cord enhancer only partially abolished the enhancer activity. Genes encoding RA synthase and the RA receptor were knocked down using specific antisense morpholino oligos (MOs), and injection of embryos with these MOs resulted in the complete disappearance of epidermal expression of Ci-Hox1 and reduction of neural expression. However, nerve cord expression was not completely repressed. These results suggest that the nerve cord enhancer is activated by two partially redundant pathways; one RA-dependent and one RA-independent.

  3. Anxiety and neural responses to infant and adult faces during pregnancy.

    PubMed

    Rutherford, Helena J V; Byrne, Simon P; Austin, Grace M; Lee, Jonathan D; Crowley, Michael J; Mayes, Linda C

    2017-03-06

    Women are vulnerable to anxiety during pregnancy and postpartum. However, little is known about antenatal anxiety and neural processing of infant-relevant information. In this experiment, the N170, P300, and LPP (late positive potential) event-related potentials were measured from 43 pregnant women as they viewed infant and adult faces, which were either neutral or distressed in expression. Mother's self-reported anxiety levels were also assessed. The N170 was comparable across face conditions and was not associated with anxiety. However, our central finding was that greater levels of antenatal anxiety were associated with a larger LPP, but only for neutral infant faces. Results suggest that antenatal anxiety may result in deeper processing of neutral, emotionally ambiguous, infant faces during pregnancy. These findings are discussed in light of other work indicating an interpretive bias toward threat in response to neutral stimuli in anxiety.

  4. Neural Dynamics of Emotional Salience Processing in Response to Voices during the Stages of Sleep.

    PubMed

    Chen, Chenyi; Sung, Jia-Ying; Cheng, Yawei

    2016-01-01

    Sleep has been related to emotional functioning. However, the extent to which emotional salience is processed during sleep is unknown. To address this concern, we investigated night sleep in healthy adults regarding brain reactivity to the emotionally (happily, fearfully) spoken meaningless syllables dada, along with correspondingly synthesized nonvocal sounds. Electroencephalogram (EEG) signals were continuously acquired during an entire night of sleep while we applied a passive auditory oddball paradigm. During all stages of sleep, mismatch negativity (MMN) in response to emotional syllables, which is an index for emotional salience processing of voices, was detected. In contrast, MMN to acoustically matching nonvocal sounds was undetected during Sleep Stage 2 and 3 as well as rapid eye movement (REM) sleep. Post-MMN positivity (PMP) was identified with larger amplitudes during Stage 3, and at earlier latencies during REM sleep, relative to wakefulness. These findings clearly demonstrated the neural dynamics of emotional salience processing during the stages of sleep.

  5. Differential Responses of Human Fetal Brain Neural Stem Cells to Zika Virus Infection.

    PubMed

    McGrath, Erica L; Rossi, Shannan L; Gao, Junling; Widen, Steven G; Grant, Auston C; Dunn, Tiffany J; Azar, Sasha R; Roundy, Christopher M; Xiong, Ying; Prusak, Deborah J; Loucas, Bradford D; Wood, Thomas G; Yu, Yongjia; Fernández-Salas, Ildefonso; Weaver, Scott C; Vasilakis, Nikos; Wu, Ping

    2017-03-14

    Zika virus (ZIKV) infection causes microcephaly in a subset of infants born to infected pregnant mothers. It is unknown whether human individual differences contribute to differential susceptibility of ZIKV-related neuropathology. Here, we use an Asian-lineage ZIKV strain, isolated from the 2015 Mexican outbreak (Mex1-7), to infect primary human neural stem cells (hNSCs) originally derived from three individual fetal brains. All three strains of hNSCs exhibited similar rates of Mex1-7 infection and reduced proliferation. However, Mex1-7 decreased neuronal differentiation in only two of the three stem cell strains. Correspondingly, ZIKA-mediated transcriptome alterations were similar in these two strains but significantly different from that of the third strain with no ZIKV-induced neuronal reduction. This study thus confirms that an Asian-lineage ZIKV strain infects primary hNSCs and demonstrates a cell-strain-dependent response of hNSCs to ZIKV infection.

  6. Neural Dynamics of Emotional Salience Processing in Response to Voices during the Stages of Sleep

    PubMed Central

    Chen, Chenyi; Sung, Jia-Ying; Cheng, Yawei

    2016-01-01

    Sleep has been related to emotional functioning. However, the extent to which emotional salience is processed during sleep is unknown. To address this concern, we investigated night sleep in healthy adults regarding brain reactivity to the emotionally (happily, fearfully) spoken meaningless syllables dada, along with correspondingly synthesized nonvocal sounds. Electroencephalogram (EEG) signals were continuously acquired during an entire night of sleep while we applied a passive auditory oddball paradigm. During all stages of sleep, mismatch negativity (MMN) in response to emotional syllables, which is an index for emotional salience processing of voices, was detected. In contrast, MMN to acoustically matching nonvocal sounds was undetected during Sleep Stage 2 and 3 as well as rapid eye movement (REM) sleep. Post-MMN positivity (PMP) was identified with larger amplitudes during Stage 3, and at earlier latencies during REM sleep, relative to wakefulness. These findings clearly demonstrated the neural dynamics of emotional salience processing during the stages of sleep. PMID:27378870

  7. Neural correlates of the behavioral-autonomic interaction response to potentially threatening stimuli

    PubMed Central

    Farrow, Tom F. D.; Johnson, Naomi K.; Hunter, Michael D.; Barker, Anthony T.; Wilkinson, Iain D.; Woodruff, Peter W. R.

    2013-01-01

    Subjective assessment of emotional valence is typically associated with both brain activity and autonomic arousal. Accurately assessing emotional salience is particularly important when perceiving threat. We sought to characterize the neural correlates of the interaction between behavioral and autonomic responses to potentially threatening visual and auditory stimuli. Twenty-five healthy male subjects underwent fMRI scanning whilst skin conductance responses (SCR) were recorded. One hundred and eighty pictures, sentences, and sounds were assessed as “harmless” or “threatening.” Individuals' stimulus-locked, phasic SCRs and trial-by-trial behavioral assessments were entered as regressors into a flexible factorial design to establish their separate autonomic and behavioral neural correlates, and convolved to examine psycho-autonomic interaction (PAI) effects. Across all stimuli, “threatening,” compared with “harmless” behavioral assessments were associated with mainly frontal and precuneus activation with specific within-modality activations including bilateral parahippocampal gyri (pictures), bilateral anterior cingulate cortex (ACC) and frontal pole (sentences), and right Heschl's gyrus and bilateral temporal gyri (sounds). Across stimulus modalities SCRs were associated with activation of parieto-occipito-thalamic regions, an activation pattern which was largely replicated within-modality. In contrast, PAI analyses revealed modality-specific activations including right fusiform/parahippocampal gyrus (pictures), right insula (sentences), and mid-cingulate gyrus (sounds). Phasic SCR activity was positively correlated with an individual's propensity to assess stimuli as “threatening.” SCRs may modulate cognitive assessments on a “harmless–threatening” dimension, thereby modulating affective tone and hence behavior. PMID:23335893

  8. Controllability Modulates the Neural Response to Predictable but not Unpredictable Threat in Humans

    PubMed Central

    Wood, Kimberly H.; Wheelock, Muriah D.; Shumen, Joshua R.; Bowen, Kenton H.; Ver Hoef, Lawrence W.; Knight, David C.

    2015-01-01

    Stress resilience is mediated, in part, by our ability to predict and control threats within our environment. Therefore, determining the neural mechanisms that regulate the emotional response to predictable and controllable threat may provide important new insight into the processes that mediate resilience to emotional dysfunction and guide the future development of interventions for anxiety disorders. To better understand the effect of predictability and controllability on threat-related brain activity in humans, two groups of healthy volunteers participated in a yoked Pavlovian fear conditioning study during functional magnetic resonance imaging (fMRI). Threat predictability was manipulated by presenting an aversive unconditioned stimulus (UCS) that was either preceded by a conditioned stimulus (i.e., predictable) or by presenting the UCS alone (i.e., unpredictable). Similar to animal model research that has employed yoked fear conditioning procedures, one group (Controllable Condition; CC), but not the other group (Uncontrollable Condition; UC) was able to terminate the UCS. The fMRI signal response within the dorsolateral prefrontal cortex (PFC), dorsomedial PFC, ventromedial PFC, and posterior cingulate was diminished during predictable compared to unpredictable threat (i.e., UCS). In addition, threat-related activity within the ventromedial PFC and bilateral hippocampus was diminished only to threats that were both predictable and controllable. These findings provide insight into how threat predictability and controllability affects the activity of brain regions (i.e., ventromedial PFC and hippocampus) involved in emotion regulation, and may have important implications for better understanding neural processes that mediate emotional resilience to stress. PMID:26149610

  9. Delineation of candidate genes responsible for structural brain abnormalities in patients with terminal deletions of chromosome 6q27

    PubMed Central

    Peddibhotla, Sirisha; Nagamani, Sandesh CS; Erez, Ayelet; Hunter, Jill V; Holder Jr, J Lloyd; Carlin, Mary E; Bader, Patricia I; Perras, Helene MF; Allanson, Judith E; Newman, Leslie; Simpson, Gayle; Immken, LaDonna; Powell, Erin; Mohanty, Aaron; Kang, Sung-Hae L; Stankiewicz, Pawel; Bacino, Carlos A; Bi, Weimin; Patel, Ankita; Cheung, Sau W

    2015-01-01

    Patients with terminal deletions of chromosome 6q present with structural brain abnormalities including agenesis of corpus callosum, hydrocephalus, periventricular nodular heterotopia, and cerebellar malformations. The 6q27 region harbors genes that are important for the normal development of brain and delineation of a critical deletion region for structural brain abnormalities may lead to a better genotype–phenotype correlation. We conducted a detailed clinical and molecular characterization of seven unrelated patients with deletions involving chromosome 6q27. All patients had structural brain abnormalities. Using array comparative genomic hybridization, we mapped the size, extent, and genomic content of these deletions. The smallest region of overlap spans 1.7 Mb and contains DLL1, THBS2, PHF10, and C6orf70 (ERMARD) that are plausible candidates for the causation of structural brain abnormalities. Our study reiterates the importance of 6q27 region in normal development of brain and helps identify putative genes in causation of structural brain anomalies. PMID:24736736

  10. Evidence for Specificity of ERP Abnormalities during Response Inhibition in ADHD Children: A Comparison with Reading Disorder Children without ADHD

    ERIC Educational Resources Information Center

    Liotti, Mario; Pliszka, Steven R.; Higgins, Kellie; Perez, Ricardo, III; Semrud-Clikeman, Margaret

    2010-01-01

    Executive function and working memory deficits are not only present in ADHD, but also in reading disorder (RD). Here, high-density ERPs were recorded during the Stop Signal Task in 53 children and adolescents: An ADHD-combined type group, a group with RD, and a healthy control group. The ADHD-C group displayed unique abnormalities of the frontal…

  11. Dynamics and cortical distribution of neural responses to 2D and 3D motion in human

    PubMed Central

    McKee, Suzanne P.; Norcia, Anthony M.

    2013-01-01

    The perception of motion-in-depth is important for avoiding collisions and for the control of vergence eye-movements and other motor actions. Previous psychophysical studies have suggested that sensitivity to motion-in-depth has a lower temporal processing limit than the perception of lateral motion. The present study used functional MRI-informed EEG source-imaging to study the spatiotemporal properties of the responses to lateral motion and motion-in-depth in human visual cortex. Lateral motion and motion-in-depth displays comprised stimuli whose only difference was interocular phase: monocular oscillatory motion was either in-phase in the two eyes (lateral motion) or in antiphase (motion-in-depth). Spectral analysis was used to break the steady-state visually evoked potentials responses down into even and odd harmonic components within five functionally defined regions of interest: V1, V4, lateral occipital complex, V3A, and hMT+. We also characterized the responses within two anatomically defined regions: the inferior and superior parietal cortex. Even harmonic components dominated the evoked responses and were a factor of approximately two larger for lateral motion than motion-in-depth. These responses were slower for motion-in-depth and were largely independent of absolute disparity. In each of our regions of interest, responses at odd-harmonics were relatively small, but were larger for motion-in-depth than lateral motion, especially in parietal cortex, and depended on absolute disparity. Taken together, our results suggest a plausible neural basis for reduced psychophysical sensitivity to rapid motion-in-depth. PMID:24198326

  12. Leukocyte abnormalities.

    PubMed

    Gabig, T G

    1980-07-01

    Certain qualitative abnormalities in neutrophils and blood monocytes are associated with frequent, severe, and recurrent bacterial infections leading to fatal sepsis, while other qualitative defects demonstrated in vitro may have few or no clinical sequelae. These qualitative defects are discussed in terms of the specific functions of locomotion, phagocytosis, degranulation, and bacterial killing.

  13. Neural basis of the stress response in a pufferfish, Takifugu obscurus.

    PubMed

    Wang, Xiaojie; Zhao, Shuang; Li, Chao; Liu, Xin; Song, Jiakun

    2015-01-01

    When faced with danger, pufferfish react with both a fast-start escape response and inflation behavior. The neural basis of these stress responses in the pufferfish has not been described. The present study reveals that during inflation behavior, the buccal cavity expands and compresses as a pump to control the direction of water flow and draws water in and out. The inflation involves a series of major anatomical modifications of the head. The greatly enlarged first branchiostegal ray and its associated hyohyoideus abductor muscle are the key mechanisms responsible for this behavior. The nerve branch innervating the hyohyoideus abductor muscle is highly developed, and its central origin at the motor nucleus of the VIIth cranial nerve was revealed by tract-tracing using the carbocyanine dye DiI. The central connections from its origin were found to be several motor nuclei in the medulla and the spinal cord, the nuclei of cranial nerve III and IV in the mesencephalon, and the pretectalis superficialis and periventricular preoptic nuclei in the diencephalon. Both the sympathetic cells and the parvocellular part of the periventricular preoptic nucleus might play a neuro-endocrine role in the rapid movement of the buccal cavity during puffing behavior in this species of pufferfish. The central circuit revealed by this study is hypothesized to mediate the C-start escape behavior and puffing behavior.

  14. A Neural Circuit That Controls Cortical State, Plasticity, and the Gain of Sensory Responses in Mouse.

    PubMed

    Stryker, Michael P

    2014-01-01

    Neurons in the visual cortex were first found to be exquisitely selective for particular properties of visual stimuli in anesthetized animals, including mice. Studies of alert mice in an apparatus that allowed them to stand or run revealed that locomotion causes a change in cortical state that dramatically increases the magnitude of responses in neurons of the visual cortex without altering selectivity, effectively changing the gain of sensory responses. Locomotion also dramatically enhances adult plasticity in the recovery from long-term visual deprivation. We have studied the elements and operation of the neural circuit responsible for the enhancement of activity and shown that it enhances plasticity even in mice not free to run. The circuit consists of projections ascending from the midbrain locomotor region (MLR) to the basal forebrain, activating cholinergic and perhaps other projections to excite inhibitory interneurons expressing vasoactive intestinal peptide (VIP) in the visual cortex. VIP cells activated by locomotion inhibit interneurons that express somatostatin (SST), thereby disinhibiting the excitatory principal neurons and allowing them to respond more strongly to effective visual stimuli. These findings reveal in alert animals how the ascending reticular activating system described in anesthetized animals 50 years ago operates to control cortical state.

  15. Dendrogenin A and B two new steroidal alkaloids increasing neural responsiveness in the deafened guinea pig

    PubMed Central

    Fransson, Anette; de Medina, Philippe; Paillasse, Michaël R.; Silvente-Poirot, Sandrine; Poirot, Marc; Ulfendahl, Mats

    2015-01-01

    Aim: To investigate the therapeutic potential for treating inner ear damage of two new steroidal alkaloid compounds, Dendrogenin A and Dendrogenin B, previously shown to be potent inductors of cell differentiation. Methods: Guinea pigs, unilaterally deafened by neomycin infusion, received a cochlear implant followed by immediate or a 2-week delayed treatment with Dendrogenin A, Dendrogenin B, and, as comparison artificial perilymph and glial cell-line derived neurotrophic factor. After a 4-week treatment period the animals were sacrificed and the cochleae processed for morphological analysis. Electrically-evoked auditory brainstem responses (eABRs) were measured weekly throughout the experiment. Results: Following immediate or delayed Dendrogenin treatment the electrical responsiveness was significantly maintained, in a similar extent as has been shown using neurotrophic factors. Histological analysis showed that the spiral ganglion neurons density was only slightly higher than the untreated group. Conclusions: Our results suggest that Dendrogenins constitute a new class of drugs with strong potential to improve cochlear implant efficacy and to treat neuropathy/synaptopathy related hearing loss. That electrical responsiveness was maintained despite a significantly reduced neural population suggests that the efficacy of cochlear implants is more related to the functional state of the spiral ganglion neurons than merely their number. PMID:26257649

  16. Rhythmic entrainment source separation: Optimizing analyses of neural responses to rhythmic sensory stimulation.

    PubMed

    Cohen, Michael X; Gulbinaite, Rasa

    2017-02-15

    Steady-state evoked potentials (SSEPs) are rhythmic brain responses to rhythmic sensory stimulation, and are often used to study perceptual and attentional processes. We present a data analysis method for maximizing the signal-to-noise ratio of the narrow-band steady-state response in the frequency and time-frequency domains. The method, termed rhythmic entrainment source separation (RESS), is based on denoising source separation approaches that take advantage of the simultaneous but differential projection of neural activity to multiple electrodes or sensors. Our approach is a combination and extension of existing multivariate source separation methods. We demonstrate that RESS performs well on both simulated and empirical data, and outperforms conventional SSEP analysis methods based on selecting electrodes with the strongest SSEP response, as well as several other linear spatial filters. We also discuss the potential confound of overfitting, whereby the filter captures noise in absence of a signal. Matlab scripts are available to replicate and extend our simulations and methods. We conclude with some practical advice for optimizing SSEP data analyses and interpreting the results.

  17. Comparison of polynomial approximations and artificial neural nets for response surfaces in engineering optimization

    NASA Technical Reports Server (NTRS)

    Carpenter, William C.

    1991-01-01

    Engineering optimization problems involve minimizing some function subject to constraints. In areas such as aircraft optimization, the constraint equations may be from numerous disciplines such as transfer of information between these disciplines and the optimization algorithm. They are also suited to problems which may require numerous re-optimizations such as in multi-objective function optimization or to problems where the design space contains numerous local minima, thus requiring repeated optimizations from different initial designs. Their use has been limited, however, by the fact that development of response surfaces randomly selected or preselected points in the design space. Thus, they have been thought to be inefficient compared to algorithms to the optimum solution. A development has taken place in the last several years which may effect the desirability of using response surfaces. It may be possible that artificial neural nets are more efficient in developing response surfaces than polynomial approximations which have been used in the past. This development is the concern of the work.

  18. Neural and behavioral responses to attractiveness in adult and infant faces.

    PubMed

    Hahn, Amanda C; Perrett, David I

    2014-10-01

    Facial attractiveness provides a very powerful motivation for sexual and parental behavior. We therefore review the importance of faces to the study of neurobiological control of human reproductive motivations. For heterosexual individuals there is a common brain circuit involving the nucleus accumbens, the medial prefrontal, dorsal anterior cingulate and the orbitofrontal cortices that is activated more by attractive than unattractive faces, particularly for faces of the opposite sex. Behavioral studies indicate parallel effects of attractiveness on incentive salience or willingness to work to see faces. There is some evidence that the reward value of opposite sex attractiveness is more pronounced in men than women, perhaps reflecting the greater importance assigned to physical attractiveness by men when evaluating a potential mate. Sex differences and similarities in response to facial attractiveness are reviewed. Studies comparing heterosexual and homosexual observers indicate the orbitofrontal cortex and mediodorsal thalamus are more activated by faces of the desired sex than faces of the less-preferred sex, independent of observer gender or sexual orientation. Infant faces activate brain regions that partially overlap with those responsive to adult faces. Infant faces provide a powerful stimulus, which also elicits sex differences in behavior and brain responses that appear dependent on sex hormones. There are many facial dimensions affecting perceptions of attractiveness that remain unexplored in neuroimaging, and we conclude by suggesting that future studies combining parametric manipulation of face images, brain imaging, hormone assays and genetic polymorphisms in receptor sensitivity are needed to understand the neural and hormonal mechanisms underlying reproductive drives.

  19. Neural and Physiological Responses to a Cold Pressor Challenge in Healthy Adolescents

    PubMed Central

    Richardson, Heidi L.; Macey, Paul M.; Kumar, Rajesh; Valladares, Edwin M.; Woo, Mary A.; Harper, Ronald M.

    2014-01-01

    Abnormal autonomic function is common in pediatric diseases. Assessment of central mechanisms underlying autonomic challenges may reveal vulnerabilities antecedent to system failure. Our objective was to characterize central markers and physiological responses to a cold pressor challenge in normal children as a critical step for establishing such screening. We performed functional magnetic resonance imaging (fMRI), and collected physiological measures during cold application to the foot in 24 healthy adolescents (15.5±0.4 years; 13 male). The protocol included a 120s baseline, 120s right-foot cold water immersion (4°C), and 120s recovery. Analyses included heart rate (HR) cross-correlations with fMRI signals. Cold application increased HR 13% 5-7s after onset, which remained elevated throughout the challenge. Respiratory rate transiently increased (peak 22%), then declined (nadir 12% below baseline), before normalizing at 75s. Cold onset rapidly increased somatosensory cortex and medullary signals, which fell after 25s. Right anterior insular cortex signals increased early, followed after 20s by the left anterior insula, with HR declining 8s later. Amygdalae signals also rose, but signals declined in the posterior cingulate cortex, caudate nucleus, hippocampus, and hypothalamus. Declining signals appeared late in the cerebellar fastigial nuclei (60-120s), and in the pons and thalamus. Somatosensory cortex, fastigial nuclei, and hypothalamic responses were principally left-sided, with bilateral responses elsewhere. Late left anterior insula responses likely underlie the HR decline; the late cerebellar pattern may modulate recovery. The laterality, timing and amplitude of normative responses, and rostral response differentiation indicate the complex integration of adolescent autonomic processing, and provide indices for pathological comparisons. PMID:24105663

  20. Using an achiasmic human visual system to quantify the relationship between the fMRI BOLD signal and neural response

    PubMed Central

    Bao, Pinglei; Purington, Christopher J; Tjan, Bosco S

    2015-01-01

    Achiasma in humans causes gross mis-wiring of the retinal-fugal projection, resulting in overlapped cortical representations of left and right visual hemifields. We show that in areas V1-V3 this overlap is due to two co-located but non-interacting populations of neurons, each with a receptive field serving only one hemifield. Importantly, the two populations share the same local vascular control, resulting in a unique organization useful for quantifying the relationship between neural and fMRI BOLD responses without direct measurement of neural activity. Specifically, we can non-invasively double local neural responses by stimulating both neuronal populations with identical stimuli presented symmetrically across the vertical meridian to both visual hemifields, versus one population by stimulating in one hemifield. Measurements from a series of such doubling experiments show that the amplitude of BOLD response is proportional to approximately 0.5 power of the underlying neural response. Reanalyzing published data shows that this inferred relationship is general. DOI: http://dx.doi.org/10.7554/eLife.09600.001 PMID:26613411

  1. Dissociation between neural and vascular responses to sympathetic stimulation : contribution of local adrenergic receptor function

    NASA Technical Reports Server (NTRS)

    Jacob, G.; Costa, F.; Shannon, J.; Robertson, D.; Biaggioni, I.

    2000-01-01

    Sympathetic activation produced by various stimuli, eg, mental stress or handgrip, evokes regional vascular responses that are often nonhomogeneous. This phenomenon is believed to be the consequence of the recruitment of differential central neural pathways or of a sympathetically mediated vasodilation. The purpose of this study was to determine whether a similar heterogeneous response occurs with cold pressor stimulation and to test the hypothesis that local differences in adrenergic receptor function could be in part responsible for this diversity. In 8 healthy subjects, local norepinephrine spillover and blood flow were measured in arms and legs at baseline and during sympathetic stimulation induced by baroreflex mechanisms (nitroprusside infusion) or cold pressor stimulation. At baseline, legs had higher vascular resistance (27+/-5 versus 17+/-2 U, P=0.05) despite lower norepinephrine spillover (0.28+/-0.04 versus 0.4+/-0.05 mg. min(-1). dL(-1), P=0.03). Norepinephrine spillover increased similarly in both arms and legs during nitroprusside infusion and cold pressor stimulation. On the other hand, during cold stimulation, vascular resistance increased in arms but not in legs (20+/-9% versus -7+/-4%, P=0.03). Increasing doses of isoproterenol and phenylephrine were infused intra-arterially in arms and legs to estimate beta-mediated vasodilation and alpha-induced vasoconstriction, respectively. beta-Mediated vasodilation was significantly lower in legs compared with arms. Thus, we report a dissociation between norepinephrine spillover and vascular responses to cold stress in lower limbs characterized by a paradoxical decrease in local resistance despite increases in sympathetic activity. The differences observed in adrenergic receptor responses cannot explain this phenomenon.

  2. Neural responses in songbird forebrain reflect learning rates, acquired salience, and stimulus novelty after auditory discrimination training.

    PubMed

    Bell, Brittany A; Phan, Mimi L; Vicario, David S

    2015-03-01

    How do social interactions form and modulate the neural representations of specific complex signals? This question can be addressed in the songbird auditory system. Like humans, songbirds learn to vocalize by imitating tutors heard during development. These learned vocalizations are important in reproductive and social interactions and in individual recognition. As a model for the social reinforcement of particular songs, male zebra finches were trained to peck for a food reward in response to one song stimulus (GO) and to withhold responding for another (NoGO). After performance reached criterion, single and multiunit neural responses to both trained and novel stimuli were obtained from multiple electrodes inserted bilaterally into two songbird auditory processing areas [caudomedial mesopallium (CMM) and caudomedial nidopallium (NCM)] of awake, restrained birds. Neurons in these areas undergo stimulus-specific adaptation to repeated song stimuli, and responses to familiar stimuli adapt more slowly than to novel stimuli. The results show that auditory responses differed in NCM and CMM for trained (GO and NoGO) stimuli vs. novel song stimuli. When subjects were grouped by the number of training days required to reach criterion, fast learners showed larger neural responses and faster stimulus-specific adaptation to all stimuli than slow learners in both areas. Furthermore, responses in NCM of fast learners were more strongly left-lateralized than in slow learners. Thus auditory responses in these sensory areas not only encode stimulus familiarity, but also reflect behavioral reinforcement in our paradigm, and can potentially be modulated by social interactions.

  3. Biophysical mechanisms responsible for pulsed low-level laser excitation of neural tissue

    NASA Astrophysics Data System (ADS)

    Wells, Jonathon; Kao, Chris; Konrad, Peter; Mahadevan-Jansen, Anita; Jansen, E. Duco

    2006-02-01

    Background/Objective: The traditional method of stimulating neural activity has been based on electrical methods and remains the gold standard to date despite inherent limitations. We have previously shown a new paradigm to in vivo neural activation based on pulsed infrared light, which provides a contact-free, spatially selective, artifact-free method without incurring tissue damage that may have significant advantages over electrical stimulation in a variety of diagnostic and therapeutic applications. The goal of this study was to investigate the physical mechanism of this phenomenon, which we propose is a photo-thermal effect from transient tissue temperature changes resulting in direct or indirect activation of transmembrane ion channels causing propagation of the action potential. Methods: Rat sciatic nerve preparation was stimulated in vivo with the Holmium:YAG laser (2.12μm), Free Electron Laser (2.1μm), Alexandrite laser (690nm), and the prototype for a solid state commercial laser nerve stimulator built by Aculight (1.87μm) to determine contributions of photobiological responses from laser tissue interactions, including temperature, pressure, electric field, and photochemistry, underlying the biophysical mechanism of stimulation. Single point temperature measurements were made with a microthermocouple adjacent to the excitation site, while an infrared camera was used for 2-D radiometry of the irradiated surface. Displacement from laser-induced pressure waves or thermoelastic expansion was measured using a PS-OCT system. Results: Results exclude a direct photochemical, electric field, or pressure wave effect as the mechanism of optical stimulation. Measurements show relative small contributions from thermoelastic expansion (300 nm) with the laser parameters used for nerve stimulation. The maximum change in tissue temperature is about 9°C (average increase of 3.66 °C) at stimulation threshold radiant exposures. Conclusion: Neural activation with pulsed

  4. Cytomixis and meiotic abnormalities during microsporogenesis are responsible for male sterility and chromosome variations in Houttuynia cordata.

    PubMed

    Guan, J-Z; Wang, J-J; Cheng, Z-H; Liu, Y; Li, Z-Y

    2012-01-17

    Houttuynia cordata (Saururaceae) is a leaf vegetable and a medicinal herb througout much of Asia. Cytomixis and meiotic abnormalities during microsporogenesis were found in two populations of H. cordata with different ploidy levels (2n = 38, 96). Cytomixis occurred in pollen mother cells during meiosis at high frequencies and with variable degrees of chromatin/chromosome transfer. Meiotic abnormalities, such as chromosome laggards, asymmetric segregation and polyads, also prevailed in pollen mother cells at metaphase of the first division and later stages. They were caused by cytomixis and resulted in very low pollen viability and male sterility. Pollen mother cells from the population with 2n = 38 showed only simultaneous cytokinesis, but most pollen mother cells from the population with 2n = 96 showed successive cytokinesis; a minority underwent simultaneous cytokinesis. Cytomixis and irregular meiotic divisions appear to be the origin of the intraspecific polyploidy in this species, which has large variations in chromosome numbers.

  5. Second language processing shows increased native-like neural responses after months of no exposure.

    PubMed

    Morgan-Short, Kara; Finger, Ingrid; Grey, Sarah; Ullman, Michael T

    2012-01-01

    Although learning a second language (L2) as an adult is notoriously difficult, research has shown that adults can indeed attain native language-like brain processing and high proficiency levels. However, it is important to then retain what has been attained, even in the absence of continued exposure to the L2--particularly since periods of minimal or no L2 exposure are common. This event-related potential (ERP) study of an artificial language tested performance and neural processing following a substantial period of no exposure. Adults learned to speak and comprehend the artificial language to high proficiency with either explicit, classroom-like, or implicit, immersion-like training, and then underwent several months of no exposure to the language. Surprisingly, proficiency did not decrease during this delay. Instead, it remained unchanged, and there was an increase in native-like neural processing of syntax, as evidenced by several ERP changes--including earlier, more reliable, and more left-lateralized anterior negativities, and more robust P600s, in response to word-order violations. Moreover, both the explicitly and implicitly trained groups showed increased native-like ERP patterns over the delay, indicating that such changes can hold independently of L2 training type. The results demonstrate that substantial periods with no L2 exposure are not necessarily detrimental. Rather, benefits may ensue from such periods of time even when there is no L2 exposure. Interestingly, both before and after the delay the implicitly trained group showed more native-like processing than the explicitly trained group, indicating that type of training also affects the attainment of native-like processing in the brain. Overall, the findings may be largely explained by a combination of forgetting and consolidation in declarative and procedural memory, on which L2 grammar learning appears to depend. The study has a range of implications, and suggests a research program with

  6. Neural responses to ambiguity involve domain-general and domain-specific emotion processing systems.

    PubMed

    Neta, Maital; Kelley, William M; Whalen, Paul J

    2013-04-01

    Extant research has examined the process of decision making under uncertainty, specifically in situations of ambiguity. However, much of this work has been conducted in the context of semantic and low-level visual processing. An open question is whether ambiguity in social signals (e.g., emotional facial expressions) is processed similarly or whether a unique set of processors come on-line to resolve ambiguity in a social context. Our work has examined ambiguity using surprised facial expressions, as they have predicted both positive and negative outcomes in the past. Specifically, whereas some people tended to interpret surprise as negatively valenced, others tended toward a more positive interpretation. Here, we examined neural responses to social ambiguity using faces (surprise) and nonface emotional scenes (International Affective Picture System). Moreover, we examined whether these effects are specific to ambiguity resolution (i.e., judgments about the ambiguity) or whether similar effects would be demonstrated for incidental judgments (e.g., nonvalence judgments about ambiguously valenced stimuli). We found that a distinct task control (i.e., cingulo-opercular) network was more active when resolving ambiguity. We also found that activity in the ventral amygdala was greater to faces and scenes that were rated explicitly along the dimension of valence, consistent with findings that the ventral amygdala tracks valence. Taken together, there is a complex neural architecture that supports decision making in the presence of ambiguity: (a) a core set of cortical structures engaged for explicit ambiguity processing across stimulus boundaries and (b) other dedicated circuits for biologically relevant learning situations involving faces.

  7. The Neural Responses to Social Cooperation in Gain and Loss Context.

    PubMed

    Sun, Peng; Zheng, Li; Li, Lin; Guo, Xiuyan; Zhang, Weidong; Zheng, Yijie

    2016-01-01

    Cooperation is pervasive and constitutes the core behavioral principle of human social life. Previous studies have revealed that mutual cooperation was reliably correlated with two reward-related brain regions, the ventral striatum and the orbitofrontal cortex. Using functional magnetic resonance imaging (fMRI), this study sought to investigate how the loss and gain contexts modulated the neural responses to mutual cooperation. Twenty-five female participants were scanned when they played a series of one-shot prisoner's dilemma games in the loss and gain contexts. Specifically, participants and partners independently chose to either cooperate with each other or not, and each was awarded or deprived of (in the gain context or the loss context, respectively) a sum of money which depended upon the interaction of their choices. Behavioral results indicated that participants cooperated in nearly half of the experiment trials and reported higher level of positive emotions for mutual cooperation in both contexts, but they cooperated more in the gain than in the loss context. At the neural level, stronger activities in the orbitofrontal cortex were observed for mutual cooperation compared with the other three outcomes in both contexts, while stronger activation in ventral striatum associated with mutual cooperation was observed in the gain context only. Together, our data indicated that, even in the one-shot interaction under loss context, participants still exhibited preference for cooperation and the rewarding experience from a mutually cooperative social interaction activated the ventral striatum and the orbitofrontal cortex, but the loss context weakened the association between the ventral striatum activation and mutual cooperation.

  8. The time-course of cortico-limbic neural responses to air hunger.

    PubMed

    Binks, Andrew P; Evans, Karleyton C; Reed, Jeffrey D; Moosavi, Shakeeb H; Banzett, Robert B

    2014-12-01

    Several studies have mapped brain regions associated with acute dyspnea perception. However, the time-course of brain activity during sustained dyspnea is unknown. Our objective was to determine the time-course of neural activity when dyspnea is sustained. Eight healthy subjects underwent brain blood oxygen level dependent functional magnetic imaging (BOLD-fMRI) during mechanical ventilation with constant mild hypercapnia (∼ 45 mm Hg). Subjects rated dyspnea (air hunger) via visual analog scale (VAS). Tidal volume (V(T)) was alternated every 90 s between high VT (0.96 ± 0.23 L) that provided respiratory comfort (12 ± 6% full scale) and low V(T) (0.48 ± 0.08 L) which evoked air hunger (56 ± 11% full scale). BOLD signal was extracted from a priori brain regions and combined with VAS data to determine air hunger related neural time-course. Air hunger onset was associated with BOLD signal increases that followed two distinct temporal profiles within sub-regions of the anterior insula, anterior cingulate and prefrontal cortices (cortico-limbic circuitry): (1) fast, BOLD signal peak <30s and (2) slow, BOLD signal peak >40s. BOLD signal during air hunger offset followed fast and slow temporal profiles symmetrical, but inverse (signal decreases) to the time-courses of air hunger onset. We conclude that differential cortico-limbic circuit elements have unique contributions to dyspnea sensation over time. We suggest that previously unidentified sub-regions are responsible for either the acute awareness or maintenance of dyspnea. These data enhance interpretation of previous studies and inform hypotheses for future dyspnea research.

  9. The Neural Responses to Social Cooperation in Gain and Loss Context

    PubMed Central

    Sun, Peng; Zheng, Li; Li, Lin; Guo, Xiuyan; Zhang, Weidong; Zheng, Yijie

    2016-01-01

    Cooperation is pervasive and constitutes the core behavioral principle of human social life. Previous studies have revealed that mutual cooperation was reliably correlated with two reward-related brain regions, the ventral striatum and the orbitofrontal cortex. Using functional magnetic resonance imaging (fMRI), this study sought to investigate how the loss and gain contexts modulated the neural responses to mutual cooperation. Twenty-five female participants were scanned when they played a series of one-shot prisoner’s dilemma games in the loss and gain contexts. Specifically, participants and partners independently chose to either cooperate with each other or not, and each was awarded or deprived of (in the gain context or the loss context, respectively) a sum of money which depended upon the interaction of their choices. Behavioral results indicated that participants cooperated in nearly half of the experiment trials and reported higher level of positive emotions for mutual cooperation in both contexts, but they cooperated more in the gain than in the loss context. At the neural level, stronger activities in the orbitofrontal cortex were observed for mutual cooperation compared with the other three outcomes in both contexts, while stronger activation in ventral striatum associated with mutual cooperation was observed in the gain context only. Together, our data indicated that, even in the one-shot interaction under loss context, participants still exhibited preference for cooperation and the rewarding experience from a mutually cooperative social interaction activated the ventral striatum and the orbitofrontal cortex, but the loss context weakened the association between the ventral striatum activation and mutual cooperation. PMID:27494142

  10. Adolescent neural response to reward is related to participant sex and task motivation.

    PubMed

    Alarcón, Gabriela; Cservenka, Anita; Nagel, Bonnie J

    2017-02-01

    Risky decision making is prominent during adolescence, perhaps contributed to by heightened sensation seeking and ongoing maturation of reward and dopamine systems in the brain, which are, in part, modulated by sex hormones. In this study, we examined sex differences in the neural substrates of reward sensitivity during a risky decision-making task and hypothesized that compared with girls, boys would show heightened brain activation in reward-relevant regions, particularly the nucleus accumbens, during reward receipt. Further, we hypothesized that testosterone and estradiol levels would mediate this sex difference. Moreover, we predicted boys would make more risky choices on the task. While boys showed increased nucleus accumbens blood oxygen level-dependent (BOLD) response relative to girls, sex hormones did not mediate this effect. As predicted, boys made a higher percentage of risky decisions during the task. Interestingly, boys also self-reported more motivation to perform well and earn money on the task, while girls self-reported higher state anxiety prior to the scan session. Motivation to earn money partially mediated the effect of sex on nucleus accumbens activity during reward. Previous research shows that increased motivation and salience of reinforcers is linked with more robust striatal BOLD response, therefore psychosocial factors, in addition to sex, may play an important role in reward sensitivity. Elucidating neurobiological mechanisms that support adolescent sex differences in risky decision making has important implications for understanding individual differences that lead to advantageous and adverse behaviors that affect health outcomes.

  11. Neural Responses to Truth Telling and Risk Propensity under Asymmetric Information

    PubMed Central

    Suzuki, Hideo; Misaki, Masaya; Krueger, Frank; Bodurka, Jerzy

    2015-01-01

    Trust is multi-dimensional because it can be characterized by subjective trust, trust antecedent, and behavioral trust. Previous research has investigated functional brain responses to subjective trust (e.g., a judgment of trustworthiness) or behavioral trust (e.g., decisions to trust) in perfect information, where all relevant information is available to all participants. In contrast, we conducted a novel examination of the patterns of functional brain activity to a trust antecedent, specifically truth telling, in asymmetric information, where one individual has more information than others, with the effect of varying risk propensity. We used functional magnetic resonance imaging (fMRI) and recruited 13 adults, who played the Communication Game, where they served as the “Sender” and chose either truth telling (true advice) or lie telling (false advice) regarding the best payment allocation for their partner. Our behavioral results revealed that subjects with recreational high risk tended to choose true advice. Moreover, fMRI results yielded that the choices of true advice were associated with increased cortical activation in the anterior rostral medial and frontopolar prefrontal cortices, middle frontal cortex, temporoparietal junction, and precuneus. Furthermore, when we specifically evaluated a role of the bilateral amygdala as the region of interest (ROI), decreased amygdala response was associated with high risk propensity, regardless of truth telling or lying. In conclusion, our results have implications for how differential functions of the cortical areas may contribute to the neural processing of truth telling. PMID:26325581

  12. Neural Responses to Truth Telling and Risk Propensity under Asymmetric Information.

    PubMed

    Suzuki, Hideo; Misaki, Masaya; Krueger, Frank; Bodurka, Jerzy

    2015-01-01

    Trust is multi-dimensional because it can be characterized by subjective trust, trust antecedent, and behavioral trust. Previous research has investigated functional brain responses to subjective trust (e.g., a judgment of trustworthiness) or behavioral trust (e.g., decisions to trust) in perfect information, where all relevant information is available to all participants. In contrast, we conducted a novel examination of the patterns of functional brain activity to a trust antecedent, specifically truth telling, in asymmetric information, where one individual has more information than others, with the effect of varying risk propensity. We used functional magnetic resonance imaging (fMRI) and recruited 13 adults, who played the Communication Game, where they served as the "Sender" and chose either truth telling (true advice) or lie telling (false advice) regarding the best payment allocation for their partner. Our behavioral results revealed that subjects with recreational high risk tended to choose true advice. Moreover, fMRI results yielded that the choices of true advice were associated with increased cortical activation in the anterior rostral medial and frontopolar prefrontal cortices, middle frontal cortex, temporoparietal junction, and precuneus. Furthermore, when we specifically evaluated a role of the bilateral amygdala as the region of interest (ROI), decreased amygdala response was associated with high risk propensity, regardless of truth telling or lying. In conclusion, our results have implications for how differential functions of the cortical areas may contribute to the neural processing of truth telling.

  13. Impacts of religious semantic priming on an intertemporal discounting task: Response time effects and neural correlates.

    PubMed

    Morgan, Jonathan; Clark, Dustin; Tripodis, Yorghos; Halloran, Christopher S; Minsky, April; Wildman, Wesley J; Durso, Raymon; McNamara, Patrick

    2016-08-01

    The purpose of this study is to test the hypothesis that religious primes would influence intertemporal discounting behaviors in neurotypical older adults, but not in participants with Parkinson's disease (PD). Furthermore, we predicted that this priming effect would be related to functional connectivity within neural networks mediating religious cognition, decision-making, reward valuing, and prospection processes. Contrary to past research with young adults, we found a significant positive relationship between religiosity and discounting rates. Religious semantic primes did not reliably shift individual discounting rates. But religious controls did respond more quickly to intertemporal decisions under the religious priming condition than the neutral condition, compared to response time differences among the participants with PD. Differences in response time were significantly associated with functional connectivity between the nucleus accumbens and various regions, including the left anterior cingulate cortex and Brodmann areas 10 and 46 in the right dorsolateral prefrontal cortex. These results suggest that religious primes influence discounting behavior via dopaminergic meso-limbic and right dorsolateral prefrontal supporting cognitive valuation and prospection processes.

  14. Neural and cortisol responses during play with human and computer partners in children with autism.

    PubMed

    Edmiston, Elliot Kale; Merkle, Kristen; Corbett, Blythe A

    2015-08-01

    Children with autism spectrum disorder (ASD) exhibit impairment in reciprocal social interactions, including play, which can manifest as failure to show social preference or discrimination between social and nonsocial stimuli. To explore mechanisms underlying these deficits, we collected salivary cortisol from 42 children 8-12 years with ASD or typical development during a playground interaction with a confederate child. Participants underwent functional MRI during a prisoner's dilemma game requiring cooperation or defection with a human (confederate) or computer partner. Search region of interest analyses were based on previous research (e.g. insula, amygdala, temporal parietal junction-TPJ). There were significant group differences in neural activation based on partner and response pattern. When playing with a human partner, children with ASD showed limited engagement of a social salience brain circuit during defection. Reduced insula activation during defection in the ASD children relative to TD children, regardless of partner type, was also a prominent finding. Insula and TPJ BOLD during defection was also associated with stress responsivity and behavior in the ASD group under playground conditions. Children with ASD engage social salience networks less than TD children during conditions of social salience, supporting a fundamental disturbance of social engagement.

  15. Behavioral triggers of skin conductance responses and their neural correlates in the primate amygdala.

    PubMed

    Laine, Christopher M; Spitler, Kevin M; Mosher, Clayton P; Gothard, Katalin M

    2009-04-01

    The amygdala plays a crucial role in evaluating the emotional significance of stimuli and in transforming the results of this evaluation into appropriate autonomic responses. Lesion and stimulation studies suggest involvement of the amygdala in the generation of the skin conductance response (SCR), which is an indirect measure of autonomic activity that has been associated with both emotion and attention. It is unclear if this involvement marks an emotional reaction to an external stimulus or sympathetic arousal regardless of its origin. We recorded skin conductance in parallel with single-unit activity from the right amygdala of two rhesus monkeys during a rewarded image viewing task and while the monkeys sat alone in a dimly lit room, drifting in and out of sleep. In both experimental conditions, we found similar SCR-related modulation of activity at the single-unit and neural population level. This suggests that the amygdala contributes to the production or modulation of SCRs regardless of the source of sympathetic arousal.

  16. Recognition of the semantics and kinematics of gestures: Neural responses to "what" and "how"?

    PubMed

    Dahan, Anat; Reiner, Miriam

    2016-10-15

    The extensive use of gestures for human-human communication, independently of culture and language, suggests an underlying universal neural mechanism for gesture recognition. The mirror neuron system (MNS) is known to respond to observed human actions, and overlaps with self-action. The minimal cues needed for activation of the MNS for gesture recognition, facial expressions and bodily dynamics, is not yet defined. Using LED-point representations of gestures, we compared two types of brain activations: 1) in response to human recognizable vs non-recognizable motion and 2) in response to human vs non-human motion. Our preliminary results show that parts of the MNS respond only to human kinematics, and not to nonhuman kinematics, suggesting that the brain has a mechanism of discriminating human from nonhuman motion, even if the pattern of motion is meaningless, but still follows biological motion patterns. This implies that mechanisms of learning-mimicking, empathy and emotional communication, are possibly constrained by biological motion patterns. We then suggest a two-tier-model of human-bodily-communication: (1) recognition of human biological kinematics; (2) recognition of meaning. Implications are both theoretical (understanding the underlying mechanism for action recognition) and applicative (in digital graphical social representations, motion should be reasonably biological to generate the same emotional and mimicking automatic mechanisms as in face-to-face social interactions).

  17. Different neural systems adjust motor behavior in response to reward and punishment.

    PubMed

    Wrase, Jana; Kahnt, Thorsten; Schlagenhauf, Florian; Beck, Anne; Cohen, Michael X; Knutson, Brian; Heinz, Andreas

    2007-07-15

    Individuals use the outcomes of their actions to adjust future behavior. However, it remains unclear whether the same neural circuits are used to adjust behavior due to rewarding and punishing outcomes. Here we used functional magnetic resonance imaging (fMRI) and a reward-providing reaction time task to investigate the adaptation of a simple motor response following four different outcomes (delivery versus omission and monetary gain versus loss). We found that activation in the thalamus and insula predicted adjustments of motor responses due to outcomes that were cued and delivered, whereas activation in the ventral striatum predicted such adjustments when outcomes were cued but omitted. Further, activation of OFC predicted improvement after all punishing outcomes, independent of whether they were omitted rewards or delivered punishments. Finally, we found that activity in anterior cingulate predicted adjustment after delivered punishments and activity in dorsal striatum predicted adaptation after delivered rewards. Our results provide evidence that different but somewhat overlapping circuits mediate the same behavioral adaptation when it is driven by different incentive outcomes.

  18. Using Force Sensors and Neural Models to Encode Tactile Stimuli as Spike-based Responses

    PubMed Central

    Kim, Elmer K.; Gerling, Gregory J.; Wellnitz, Scott A.; Lumpkin, Ellen A.

    2011-01-01

    Tactile sensors will augment the next generation of prosthetic limbs. However, currently available sensors do not produce biologically-compatible output. This work seeks to illustrate that a force sensor combined with a bi-phasic, neural spiking algorithm, or spiking-sensor, can produce spiking patterns similar to that of the slowly adapting type I (SAI) mechanoreceptor. Experiments were conducted where first spike latency and inter-spike interval, in response to a rapidly delivered (100 ms) sustained displacement (1.1, 1.3, 1.5 mm for 5 s), were compared between the spiking-sensor and SAI recording. The results indicated that the predicted spike times were similar, in magnitude and increasing linear trend, to those observed with the SAI. Over the three displacements, average dynamic ISIs were 7.3, 4.2, 3.8 ms for the spiking-sensor and 6.2, 6.9, 4.1 ms for the SAI, while average static ISIs were 69.0, 45.2, 35.1 ms and 159.9, 69.6, 38.8 ms. The predicted first spike latencies (74.3, 73.9, 96.3 ms) lagged in comparison to those observed for the SAI (26.8, 31.7, 28.8 ms), which may be due to both the different applied force ramp-ups and the SAI’s exquisite dynamic sensitivity range and rapid response time. PMID:21826287

  19. Natural grouping of neural responses reveals spatially segregated clusters in prearcuate cortex

    PubMed Central

    Kiani, Roozbeh; Cueva, Christopher J.; Reppas, John B.; Peixoto, Diogo; Ryu, Stephen I.; Newsome, William T.

    2015-01-01

    Summary A fundamental challenge in studying the frontal lobe is to parcellate this cortex into ‘natural’ functional modules despite the absence of topographic maps, which are so helpful in primary sensory areas. Here we show that unsupervised clustering algorithms, applied to 96-channel array recordings from prearcuate gyrus, reveal spatially segregated sub-networks that remain stable across behavioral contexts. Looking for natural groupings of neurons based on response similarities, we discovered that the recorded area includes at least two spatially segregated sub-networks that differentially represent behavioral choice and reaction time. Importantly, these sub-networks are detectable during different behavioral states, and surprisingly, are defined better by ‘common noise’ than task-evoked responses. Our parcellation process works well on ‘spontaneous’ neural activity, and thus bears strong resemblance to the identification of ‘resting state’ networks in fMRI datasets. Our results demonstrate a powerful new tool for identifying cortical sub-networks by objective classification of simultaneously recorded electrophysiological activity. PMID:25728571

  20. From agents to objects: sexist attitudes and neural responses to sexualized targets.

    PubMed

    Cikara, Mina; Eberhardt, Jennifer L; Fiske, Susan T

    2011-03-01

    Agency attribution is a hallmark of mind perception; thus, diminished attributions of agency may disrupt social-cognition processes typically elicited by human targets. The current studies examine the effect of perceivers' sexist attitudes on associations of agency with, and neural responses to, images of sexualized and clothed men and women. In Study 1, male (but not female) participants with higher hostile sexism scores more quickly associated sexualized women with first-person action verbs ("handle") and clothed women with third-person action verbs ("handles") than the inverse, as compared to their less sexist peers. In Study 2, hostile sexism correlated negatively with activation of regions associated with mental state attribution-medial prefrontal cortex, posterior cingulate, temporal poles-but only when viewing sexualized women. Heterosexual men best recognized images of sexualized female bodies (but not faces), as compared with other targets' bodies; however, neither face nor body recognition was related to hostile sexism, suggesting that the fMRI findings are not explained by more or less attention to sexualized female targets. Diminished mental state attribution is not unique to targets that people prefer to avoid, as in dehumanization of stigmatized people. The current studies demonstrate that appetitive social targets may elicit a similar response depending on perceivers' attitudes toward them.

  1. Brain Tissue Responses to Neural Implants Impact Signal Sensitivity and Intervention Strategies

    PubMed Central

    2015-01-01

    Implantable biosensors are valuable scientific tools for basic neuroscience research and clinical applications. Neurotechnologies provide direct readouts of neurological signal and neurochemical processes. These tools are generally most valuable when performance capacities extend over months and years to facilitate the study of memory, plasticity, and behavior or to monitor patients’ conditions. These needs have generated a variety of device designs from microelectrodes for fast scan cyclic voltammetry (FSCV) and electrophysiology to microdialysis probes for sampling and detecting various neurochemicals. Regardless of the technology used, the breaching of the blood–brain barrier (BBB) to insert devices triggers a cascade of biochemical pathways resulting in complex molecular and cellular responses to implanted devices. Molecular and cellular changes in the microenvironment surrounding an implant include the introduction of mechanical strain, activation of glial cells, loss of perfusion, secondary metabolic injury, and neuronal degeneration. Changes to the tissue microenvironment surrounding the device can dramatically impact electrochemical and electrophysiological signal sensitivity and stability over time. This review summarizes the magnitude, variability, and time course of the dynamic molecular and cellular level neural tissue responses induced by state-of-the-art implantable devices. Studies show that insertion injuries and foreign body response can impact signal quality across all implanted central nervous system (CNS) sensors to varying degrees over both acute (seconds to minutes) and chronic periods (weeks to months). Understanding the underlying biological processes behind the brain tissue response to the devices at the cellular and molecular level leads to a variety of intervention strategies for improving signal sensitivity and longevity. PMID:25546652

  2. Human muscle sympathetic neural and haemodynamic responses to tilt following spaceflight.

    PubMed

    Levine, Benjamin D; Pawelczyk, James A; Ertl, Andrew C; Cox, James F; Zuckerman, Julie H; Diedrich, André; Biaggioni, Italo; Ray, Chester A; Smith, Michael L; Iwase, Satoshi; Saito, Mitsuru; Sugiyama, Yoshiki; Mano, Tadaaki; Zhang, Rong; Iwasaki, Kenichi; Lane, Lynda D; Buckey, Jay C; Cooke, William H; Baisch, Friedhelm J; Eckberg, Dwain L; Blomqvist, C Gunnar

    2002-01-01

    Orthostatic intolerance is common when astronauts return to Earth: after brief spaceflight, up to two-thirds are unable to remain standing for 10 min. Previous research suggests that susceptible individuals are unable to increase their systemic vascular resistance and plasma noradrenaline concentrations above pre-flight upright levels. In this study, we tested the hypothesis that adaptation to the microgravity of space impairs sympathetic neural responses to upright posture on Earth. We studied six astronauts approximately 72 and 23 days before and on landing day after the 16 day Neurolab space shuttle mission. We measured heart rate, arterial pressure and cardiac output, and calculated stroke volume and total peripheral resistance, during supine rest and 10 min of 60 deg upright tilt. Muscle sympathetic nerve activity was recorded in five subjects, as a direct measure of sympathetic nervous system responses. As in previous studies, mean (+/- S.E.M.) stroke volume was lower (46 +/- 5 vs. 76 +/- 3 ml, P = 0.017) and heart rate was higher (93 +/- 1 vs. 74 +/- 4 beats min(-1), P = 0.002) during tilt after spaceflight than before spaceflight. Total peripheral resistance during tilt post flight was higher in some, but not all astronauts (1674 +/- 256 vs. 1372 +/- 62 dynes s cm(-5), P = 0.32). No crew member exhibited orthostatic hypotension or presyncopal symptoms during the 10 min of postflight tilting. Muscle sympathetic nerve activity was higher post flight in all subjects, in supine (27 +/- 4 vs. 17 +/- 2 bursts min(-1), P = 0.04) and tilted (46 +/- 4 vs. 38 +/- 3 bursts min(-1), P = 0.01) positions. A strong (r(2) = 0.91-1.00) linear correlation between left ventricular stroke volume and muscle sympathetic nerve activity suggested that sympathetic responses were appropriate for the haemodynamic challenge of upright tilt and were unaffected by spaceflight. We conclude that after 16 days of spaceflight, muscle sympathetic nerve responses to upright tilt are normal.

  3. Human muscle sympathetic neural and haemodynamic responses to tilt following spaceflight

    NASA Technical Reports Server (NTRS)

    Levine, Benjamin D.; Pawelczyk, James A.; Ertl, Andrew C.; Cox, James F.; Zuckerman, Julie H.; Diedrich, Andre; Biaggioni, Italo; Ray, Chester A.; Smith, Michael L.; Iwase, Satoshi; Saito, Mitsuru; Sugiyama, Yoshiki; Mano, Tadaaki; Zhang, Rong; Iwasaki, Kenichi; Lane, Lynda D.; Buckey, Jay C Jr; Cooke, William H.; Baisch, Friedhelm J.; Eckberg, Dwain L.; Blomqvist, C. Gunnar

    2002-01-01

    Orthostatic intolerance is common when astronauts return to Earth: after brief spaceflight, up to two-thirds are unable to remain standing for 10 min. Previous research suggests that susceptible individuals are unable to increase their systemic vascular resistance and plasma noradrenaline concentrations above pre-flight upright levels. In this study, we tested the hypothesis that adaptation to the microgravity of space impairs sympathetic neural responses to upright posture on Earth. We studied six astronauts approximately 72 and 23 days before and on landing day after the 16 day Neurolab space shuttle mission. We measured heart rate, arterial pressure and cardiac output, and calculated stroke volume and total peripheral resistance, during supine rest and 10 min of 60 deg upright tilt. Muscle sympathetic nerve activity was recorded in five subjects, as a direct measure of sympathetic nervous system responses. As in previous studies, mean (+/- S.E.M.) stroke volume was lower (46 +/- 5 vs. 76 +/- 3 ml, P = 0.017) and heart rate was higher (93 +/- 1 vs. 74 +/- 4 beats min(-1), P = 0.002) during tilt after spaceflight than before spaceflight. Total peripheral resistance during tilt post flight was higher in some, but not all astronauts (1674 +/- 256 vs. 1372 +/- 62 dynes s cm(-5), P = 0.32). No crew member exhibited orthostatic hypotension or presyncopal symptoms during the 10 min of postflight tilting. Muscle sympathetic nerve activity was higher post flight in all subjects, in supine (27 +/- 4 vs. 17 +/- 2 bursts min(-1), P = 0.04) and tilted (46 +/- 4 vs. 38 +/- 3 bursts min(-1), P = 0.01) positions. A strong (r(2) = 0.91-1.00) linear correlation between left ventricular stroke volume and muscle sympathetic nerve activity suggested that sympathetic responses were appropriate for the haemodynamic challenge of upright tilt and were unaffected by spaceflight. We conclude that after 16 days of spaceflight, muscle sympathetic nerve responses to upright tilt are normal.

  4. Stimulation of adenosine A2A receptors reduces intracellular cholesterol accumulation and rescues mitochondrial abnormalities in human neural cell models of Niemann-Pick C1.

    PubMed

    Ferrante, A; De Nuccio, C; Pepponi, R; Visentin, S; Martire, A; Bernardo, A; Minghetti, L; Popoli, P

    2016-04-01

    Niemann Pick C 1 (NPC1) disease is an incurable, devastating lysosomal-lipid storage disorder characterized by hepatosplenomegaly, progressive neurological impairment and early death. Current treatments are very limited and the research of new therapeutic targets is thus mandatory. We recently showed that the stimulation of adenosine A2A receptors (A2ARs) rescues the abnormal phenotype of fibroblasts from NPC1 patients suggesting that A2AR agonists could represent a therapeutic option for this disease. However, since all NPC1 patients develop severe neurological symptoms which can be ascribed to the complex pathology occurring in both neurons and oligodendrocytes, in the present paper we tested the effects of the A2AR agonist CGS21680 in human neuronal and oligodendroglial NPC1 cell lines (i.e. neuroblastoma SH-SY5Y and oligodendroglial MO3.13 transiently transfected with NPC1 small interfering RNA). The down-regulation of the NPC1 protein effectively resulted in intracellular cholesterol accumulation and altered mitochondrial membrane potential. Both effects were significantly attenuated by CGS21680 (500 nM). The protective effects of CGS were prevented by the selective A2AR antagonist ZM241385 (500 nM). The involvement of calcium modulation was demonstrated by the ability of Bapta-AM (5-7 μM) in reverting the effect of CGS. The A2A-dependent activity was prevented by the PKA-inhibitor KT5720, thus showing the involvement of the cAMP/PKA signaling. These findings provide a clear in vitro proof of concept that A2AR agonists are promising potential drugs for NPC disease.

  5. Behavioral and neural responses of toads to salt solutions correlate with basolateral membrane potential of epidermal cells of the skin.

    PubMed

    Hillyard, Stanley D; Baula, Victor; Tuttle, Wendy; Willumsen, Niels J; Larsen, Erik H

    2007-10-01

    Dehydrated toads initiated water absorption response (WR) behavior and absorbed water from dilute NaCl solutions. With 200-250 mM NaCl, WR behavior and water absorption were both suppressed. With 200-250 mM Na-gluconate, WR initiation was significantly greater than with NaCl but water loss was greater. Neural recordings from spinal nerve #6 showed a greater integrated response to 250 mM NaCl than to 250 mM Na-gluconate, whereas a larger rinse response was seen with Na-gluconate. Studies with isolated epithelium showed a large increase in conductance (G(t)) when 250 mM NaCl replaced NaCl Ringer's as the apical bathing solution that was accompanied by depolarization of the transepithelial potential (V(t)) and basolateral membrane potential (V(b)). Depolarization of V(b) corresponded with the neural response to 250 mM NaCl. When 250 mM Na-gluconate replaced Ringer's as the apical solution G(t) remained low, V(b) transiently hyperpolarized to values near the equilibrium potential for K(+) and corresponded with the reduced neural response. These results support the hypothesis that chemosensory function of the skin is analogous to that of mammalian taste cells but utilizes paracellular ion transport to a greater degree.

  6. Negative affect and neural response to palatable food intake in bulimia nervosa.

    PubMed

    Bohon, Cara; Stice, Eric

    2012-06-01

    Binge eating is often preceded by reports of negative affect, but the mechanism by which affect may lead to binge eating is unclear. This study evaluated the effect of negative affect on neural response to anticipation and receipt of palatable food in women with bulimia nervosa (BN) versus healthy controls. We also evaluated connectivity between the amygdala and reward-related brain regions. Females with and without BN (n=26) underwent functional magnetic resonance imaging (fMRI) during receipt and anticipated receipt of chocolate milkshake and a tasteless solution. We measured negative affect just prior to the scan. Women with BN showed a positive correlation between negative affect and activity in the putamen, caudate, and pallidum during anticipated receipt of milkshake (versus tasteless solution). There were no significant relations between negative affect and receipt of milkshake. Connectivity analyses revealed a greater relation of amygdala activity to activation in the left putamen and insula during anticipated receipt of milkshake in the bulimia group relative to the control group. The opposite pattern was found for the taste of milkshake; the control group showed a greater relation of amygdala activity to activation in the left putamen and insula in response to milkshake receipt than the bulimia group. Results show that as negative affect increases, so does responsivity of reward regions to anticipated intake of palatable food, implying that negative affect may increase the reward value of food for individuals with bulimia nervosa or that negative affect has become a conditioned cue due to a history of binge eating in a negative mood.

  7. Characterization of calcium responses and electrical activity in differentiating mouse neural progenitor cells in vitro.

    PubMed

    de Groot, Martje W G D M; Dingemans, Milou M L; Rus, Katinka H; de Groot, Aart; Westerink, Remco H S

    2014-02-01

    In vitro methods for developmental neurotoxicity (DNT) testing have the potential to reduce animal use and increase insight into cellular and molecular mechanisms underlying chemical-induced alterations in the development of functional neuronal networks. Mouse neural progenitor cells (mNPCs) differentiate into nervous system-specific cell types and have proven valuable to detect DNT using biochemical and morphological techniques. We therefore investigated a number of functional neuronal parameters in primary mNPCs to explore their applicability for neurophysiological in vitro DNT testing. Immunocytochemistry confirmed that mNPCs express neuronal, glial, and progenitor markers at various differentiation durations (1, 7, 14, and 21 days). Because intracellular calcium ([Ca(2+)]i) plays an essential role in neuronal development and function, we measured stimulus-evoked changes in [Ca(2+)]i at these differentiation durations using the Ca(2+)-responsive dye Fura-2. Increases in [Ca(2+)]i (averages ranging from 65 to 226 nM) were evoked by depolarization, ATP, l-glutamic acid, acetylcholine, and dopamine (up to 87%, 57%, 93%, 28%, and 37% responding cells, respectively) and to a lesser extent by serotonin and gamma-aminobutyric acid (both up to 10% responding cells). Notably, the changes in percentage of responsive cells and their response amplitudes over time indicate changes in the expression and functionality of the respective neurotransmitter receptors and related calcium signaling pathways during in vitro differentiation. The development of functional intercellular signaling pathways was confirmed using multielectrode arrays, demonstrating that mNPCs develop electrical activity within 1-2 weeks of differentiation (55% active wells at 14 days of differentiation; mean spike rate of 1.16 spikes/s/electrode). The combined data demonstrate that mNPCs develop functional neuronal characteristics in vitro, making it a promising model to study chemical-induced effects on the

  8. Influence of Menstrual Cycle Phase on Neural and Craving Responses to Appetitive Smoking Cues in Naturally Cycling Females

    PubMed Central

    Jagannathan, Kanchana; Wetherill, Reagan R.; Johnson, Barbara; Kelly, Shannon; Langguth, Jamison; Mumma, Joel; Childress, Anna Rose

    2015-01-01

    Introdu ction: Functional magnetic resonance imaging (fMRI) has been used extensively in an attempt to understand brain vulnerabilities that mediate maladaptive responses to drug cues. Using perfusion fMRI, we have consistently shown reward-related activation (medial orbitofrontal cortex/ventral striatum) to smoking cues (SCs). Because preclinical and clinical studies generally show that progesterone may reduce reward and craving, we hypothesized that females in the follicular phase of the cycle (FPs; when progesterone levels are low) would have greater reward-related neural responses to SCs compared with females in the luteal phase (LPs). Methods: Sated cigarette-dependent premenopausal naturally cycling females underwent pseudo-continuous arterial spin-labeled perfusion fMRI during exposure to 10-min audio visual clips of appetitive SCs and non-SCs. Brain responses to SCs relative to non-SCs were examined among females grouped according to menstrual cycle (MC) phase at the time of scanning (22 FPs, 15 LPs). Craving scores were acquired pre- and post-SC exposure. Results: FPs showed increased neural responses to SCs compared with non-SCs in the medial orbitofrontal cortex (p ≤ .05corrected), whereas LPs did not. FPs reported SC-elicited craving (p ≤ .005), whereas LPs did not. Within FPs, SC-induced craving correlated with increased neural responses in the anterior insula (r = 0.73, p < .0001). Conclusions: FPs may be more vulnerable to relapse during appetitive SC exposure than LPs. Because the influence of MC phase on drug cue neural activity has not been examined, these results contribute to our knowledge of the neurobiological underpinnings of responses to drug cues, and they highlight the importance of monitoring menstrual cycle phase in all areas of addiction research. PMID:25762748

  9. Neural Response during the Activation of the Attachment System in Patients with Borderline Personality Disorder: An fMRI Study.

    PubMed

    Buchheim, Anna; Erk, Susanne; George, Carol; Kächele, Horst; Martius, Philipp; Pokorny, Dan; Spitzer, Manfred; Walter, Henrik

    2016-01-01

    Individuals with borderline personality disorder (BPD) are characterized by emotional instability, impaired emotion regulation and unresolved attachment patterns associated with abusive childhood experiences. We investigated the neural response during the activation of the attachment system in BPD patients compared to healthy controls using functional magnetic resonance imaging (fMRI). Eleven female patients with BPD without posttraumatic stress disorder (PTSD) and 17 healthy female controls matched for age and education were telling stories in the scanner in response to the Adult Attachment Projective Picture System (AAP), an eight-picture set assessment of adult attachment. The picture set includes theoretically-derived attachment scenes, such as separation, death, threat and potential abuse. The picture presentation order is designed to gradually increase the activation of the attachment system. Each picture stimulus was presented for 2 min. Analyses examine group differences in attachment classifications and neural activation patterns over the course of the task. Unresolved attachment was associated with increasing amygdala activation over the course of the attachment task in patients as well as controls. Unresolved controls, but not patients, showed activation in the right dorsolateral prefrontal cortex (DLPFC) and the rostral cingulate zone (RCZ). We interpret this as a neural signature of BPD patients' inability to exert top-down control under conditions of attachment distress. These findings point to possible neural mechanisms for underlying affective dysregulation in BPD in the context of attachment trauma and fear.

  10. Neural Response during the Activation of the Attachment System in Patients with Borderline Personality Disorder: An fMRI Study

    PubMed Central

    Buchheim, Anna; Erk, Susanne; George, Carol; Kächele, Horst; Martius, Philipp; Pokorny, Dan; Spitzer, Manfred; Walter, Henrik

    2016-01-01

    Individuals with borderline personality disorder (BPD) are characterized by emotional instability, impaired emotion regulation and unresolved attachment patterns associated with abusive childhood experiences. We investigated the neural response during the activation of the attachment system in BPD patients compared to healthy controls using functional magnetic resonance imaging (fMRI). Eleven female patients with BPD without posttraumatic stress disorder (PTSD) and 17 healthy female controls matched for age and education were telling stories in the scanner in response to the Adult Attachment Projective Picture System (AAP), an eight-picture set assessment of adult attachment. The picture set includes theoretically-derived attachment scenes, such as separation, death, threat and potential abuse. The picture presentation order is designed to gradually increase the activation of the attachment system. Each picture stimulus was presented for 2 min. Analyses examine group differences in attachment classifications and neural activation patterns over the course of the task. Unresolved attachment was associated with increasing amygdala activation over the course of the attachment task in patients as well as controls. Unresolved controls, but not patients, showed activation in the right dorsolateral prefrontal cortex (DLPFC) and the rostral cingulate zone (RCZ). We interpret this as a neural signature of BPD patients’ inability to exert top-down control under conditions of attachment distress. These findings point to possible neural mechanisms for underlying affective dysregulation in BPD in the context of attachment trauma and fear. PMID:27531977

  11. Active Control of Wind-Tunnel Model Aeroelastic Response Using Neural Networks

    NASA Technical Reports Server (NTRS)

    Scott, Robert C.

    2000-01-01

    NASA Langley Research Center, Hampton, VA 23681 Under a joint research and development effort conducted by the National Aeronautics and Space Administration and The Boeing Company (formerly McDonnell Douglas) three neural-network based control systems were developed and tested. The control systems were experimentally evaluated using a transonic wind-tunnel model in the Langley Transonic Dynamics Tunnel. One system used a neural network to schedule flutter suppression control laws, another employed a neural network in a predictive control scheme, and the third employed a neural network in an inverse model control scheme. All three of these control schemes successfully suppressed flutter to or near the limits of the testing apparatus, and represent the first experimental applications of neural networks to flutter suppression. This paper will summarize the findings of this project.

  12. Moral judgment modulates neural responses to the perception of other’s pain: an ERP study

    PubMed Central

    Cui, Fang; Ma, Ning; Luo, Yue-jia

    2016-01-01

    Morality and empathy are both crucial in building human society. Yet the relationship between them has been merely explored. The present study revealed how the morality influenced empathy for pain by comparing the ERPs elicited by pictures showing the targets’ in pain primed by different moral information about the targets. We found that when the target was a moral one or a neutral one, the painful pictures elicited significantly larger amplitude in N2 than the non-painful pictures, but when the target was an immoral one, the difference between the amplitudes of N2 component elicited by painful and non-painful pictures became insignificant. We proposed that this effect was induced by the decreased affective arousal when observing an immoral person in pain. The reduced neural response towards the immoral one’s pain can keep us alert when we face the potentially dangerous people thereby increasing our chance of survival. SLORTEA results showed the source of this difference in N2 localized in the ventral medial prefrontal cortex (vmPFC) and the rostral anterior cingulate cortex (rACC) areas. PMID:26865250

  13. Perceptual and neural responses to sweet taste in humans and rodents

    PubMed Central

    Lemon, Christian H.

    2015-01-01

    Introduction This mini-review discusses some of the parallels between rodent neurophysiological and human psychophysical data concerning temperature effects on sweet taste. Methods and Purpose “Sweet” is an innately rewarding taste sensation that is associated in part with foods that contain calories in the form of sugars. Humans and other mammals can show unconditioned preference for select sweet stimuli. Such preference is poised to influence diet selection and, in turn, nutritional status, which underscores the importance of delineating the physiological mechanisms for sweet taste with respect to their influence on human health. Advances in our knowledge of the biology of sweet taste in humans have arisen in part through studies on mechanisms of gustatory processing in rodent models. Along this line, recent work has revealed there are operational parallels in neural systems for sweet taste between mice and humans, as indexed by similarities in the effects of temperature on central neurophysiological and psychophysical responses to sucrose in these species. Such association strengthens the postulate that rodents can serve as effective models of particular mechanisms of appetitive taste processing. Data supporting this link are discussed here, as are rodent and human data that shed light on relationships between mechanisms for sweet taste and ingestive disorders, such as alcohol abuse. Results and Conclusions Rodent models have utility for understanding mechanisms of taste processing that may pertain to human flavor perception. Importantly, there are limitations to generalizing data from rodents, albeit parallels across species do exist. PMID:26388965

  14. The development of aesthetic responses to music and their underlying neural and psychological mechanisms.

    PubMed

    Nieminen, S; Istók, E; Brattico, E; Tervaniemi, M; Huotilainen, M

    2011-10-01

    In the field of psychology, the first studies in experimental aesthetics were conducted approximately 140 years ago. Since then, research has mainly concentrated on aesthetic responses to visual art. Both the aesthetic experience of music and, especially, its development have received rather limited attention. Moreover, until now, very little attention has been paid to the investigation of the aesthetic experience of music using neuroscientific methods. Aesthetic experiences are multidimensional and include inter alia sensory, perceptual, affective, and cognitive components. Aesthetic processes are usually experienced as pleasing and rewarding and are, thus, important and valuable experiences for many people. Because of their multidimensional nature, these processes employ several brain areas. In the present review, we examine important psychological and neural mechanisms that are believed to contribute to the development of aesthetic experiences of music. We also discuss relevant research findings. With the present review, we wish to provoke further discussion and possible future investigations as we consider the investigation of aesthetic experiences to be important both scientifically and with respect to potential clinical applications.

  15. On chirp stimuli and neural synchrony in the suprathreshold auditory brainstem response.

    PubMed

    Petoe, Matthew A; Bradley, Andrew P; Wilson, Wayne J

    2010-07-01

    The chirp-evoked ABR has been regarded as a more synchronous response than the click-evoked ABR, referring to the belief that the chirp stimulates lower-, mid-, and higher-frequency regions of the cochlea simultaneously. In this study a variety of tools were used to analyze the synchronicity of ABRs evoked by chirp- and click-stimuli at 40 dB HL in 32 normal hearing subjects aged 18 to 55 years (mean=24.8 years, SD=7.1 years). Compared to the click-evoked ABRs, the chirp-evoked ABRs showed larger wave V amplitudes, but an absence of earlier waves in the grand averages, larger wave V latency variance, smaller FFT magnitudes at the higher component frequencies, and larger phase variance at the higher component frequencies. These results strongly suggest that the chirp-evoked ABRs exhibited less synchrony than the click-evoked ABRs in this study. It is proposed that the temporal compensation offered by chirp stimuli is sufficient to increase neural recruitment (as measured by wave V amplitude), but that destructive phase interactions still exist along the cochlea partition, particularly in the low frequency portions of the cochlea where more latency jitter is expected. The clinical implications of these findings are discussed.

  16. Temperament trait of sensory processing sensitivity moderates cultural differences in neural response

    PubMed Central

    Ketay, Sarah; Hedden, Trey; Aron, Elaine N.; Rose Markus, Hazel; Gabrieli, John D. E.

    2010-01-01

    This study focused on a possible temperament-by-culture interaction. Specifically, it explored whether a basic temperament/personality trait (sensory processing sensitivity; SPS), perhaps having a genetic component, might moderate a previously established cultural difference in neural responses when making context-dependent vs context-independent judgments of simple visual stimuli. SPS has been hypothesized to underlie what has been called inhibitedness or reactivity in infants, introversion in adults, and reactivity or responsivness in diverse animal species. Some biologists view the trait as one of two innate strategies—observing carefully before acting vs being first to act. Thus the central characteristic of SPS is hypothesized to be a deep processing of information. Here, 10 European-Americans and 10 East Asians underwent functional magnetic resonance imaging while performing simple visuospatial tasks emphasizing judgments that were either context independent (typically easier for Americans) or context dependent (typically easier for Asians). As reported elsewhere, each group exhibited greater activation for the culturally non-preferred task in frontal and parietal regions associated with greater effort in attention and working memory. However, further analyses, reported here for the first time, provided preliminary support for moderation by SPS. Consistent with the careful-processing theory, high-SPS individuals showed little cultural difference; low-SPS, strong culture differences. PMID:20388694

  17. Second-hand stress: inhalation of stress sweat enhances neural response to neutral faces

    PubMed Central

    Rubin, Denis; Botanov, Yevgeny; Hajcak, Greg

    2012-01-01

    This study investigated whether human chemosensory-stress cues affect neural activity related to the evaluation of emotional stimuli. Chemosensory stimuli were obtained from the sweat of 64 male donors during both stress (first-time skydive) and control (exercise) conditions, indistinguishable by odor. We then recorded event-related potentials (ERPs) from an unrelated group of 14 participants while they viewed faces morphed with neutral-to-angry expressions and inhaled nebulized stress and exercise sweat in counter-balanced blocks, blind to condition. Results for the control condition ERPs were consistent with previous findings: the late positive potential (LPP; 400–600 ms post stimulus) in response to faces was larger for threatening than both neutral and ambiguous faces. In contrast, the stress condition was associated with a heightened LPP across all facial expressions; relative to control, the LPP was increased for both ambiguous and neutral faces in the stress condition. These results suggest that stress sweat may impact electrocortical activity associated with attention to salient environmental cues, potentially increasing attentiveness to otherwise inconspicuous stimuli. PMID:21208988

  18. Shape Optimization of Supersonic Turbines Using Response Surface and Neural Network Methods

    NASA Technical Reports Server (NTRS)

    Papila, Nilay; Shyy, Wei; Griffin, Lisa W.; Dorney, Daniel J.

    2001-01-01

    Turbine performance directly affects engine specific impulse, thrust-to-weight ratio, and cost in a rocket propulsion system. A global optimization framework combining the radial basis neural network (RBNN) and the polynomial-based response surface method (RSM) is constructed for shape optimization of a supersonic turbine. Based on the optimized preliminary design, shape optimization is performed for the first vane and blade of a 2-stage supersonic turbine, involving O(10) design variables. The design of experiment approach is adopted to reduce the data size needed by the optimization task. It is demonstrated that a major merit of the global optimization approach is that it enables one to adaptively revise the design space to perform multiple optimization cycles. This benefit is realized when an optimal design approaches the boundary of a pre-defined design space. Furthermore, by inspecting the influence of each design variable, one can also gain insight into the existence of multiple design choices and select the optimum design based on other factors such as stress and materials considerations.

  19. Understanding less than nothing: children's neural response to negative numbers shifts across age and accuracy.

    PubMed

    Gullick, Margaret M; Wolford, George

    2013-01-01

    We examined the brain activity underlying the development of our understanding of negative numbers, which are amounts lacking direct physical counterparts. Children performed a paired comparison task with positive and negative numbers during an fMRI session. As previously shown in adults, both pre-instruction fifth-graders and post-instruction seventh-graders demonstrated typical behavioral and neural distance effects to negative numbers, where response times and parietal and frontal activity increased as comparison distance decreased. We then determined the factors impacting the distance effect in each age group. Behaviorally, the fifth-grader distance effect for negatives was significantly predicted only by positive comparison accuracy, indicating that children who were generally better at working with numbers were better at comparing negatives. In seventh-graders, negative number comparison accuracy significantly predicted their negative number distance effect, indicating that children who were better at working with negative numbers demonstrated a more typical distance effect. Across children, as age increased, the negative number distance effect increased in the bilateral IPS and decreased frontally, indicating a frontoparietal shift consistent with previous numerical development literature. In contrast, as negative comparison task accuracy increased, the parietal distance effect increased in the left IPS and decreased in the right, possibly indicating a change from an approximate understanding of negatives' values to a more exact, precise representation (particularly supported by the left IPS) with increasing expertise. These shifts separately indicate the effects of increasing maturity generally in numeric processing and specifically in negative number understanding.

  20. Temperament trait of sensory processing sensitivity moderates cultural differences in neural response.

    PubMed

    Aron, Arthur; Ketay, Sarah; Hedden, Trey; Aron, Elaine N; Rose Markus, Hazel; Gabrieli, John D E

    2010-06-01

    This study focused on a possible temperament-by-culture interaction. Specifically, it explored whether a basic temperament/personality trait (sensory processing sensitivity; SPS), perhaps having a genetic component, might moderate a previously established cultural difference in neural responses when making context-dependent vs context-independent judgments of simple visual stimuli. SPS has been hypothesized to underlie what has been called inhibitedness or reactivity in infants, introversion in adults, and reactivity or responsivness in diverse animal species. Some biologists view the trait as one of two innate strategies-observing carefully before acting vs being first to act. Thus the central characteristic of SPS is hypothesized to be a deep processing of information. Here, 10 European-Americans and 10 East Asians underwent functional magnetic resonance imaging while performing simple visuospatial tasks emphasizing judgments that were either context independent (typically easier for Americans) or context dependent (typically easier for Asians). As reported elsewhere, each group exhibited greater activation for the culturally non-preferred task in frontal and parietal regions associated with greater effort in attention and working memory. However, further analyses, reported here for the first time, provided preliminary support for moderation by SPS. Consistent with the careful-processing theory, high-SPS individuals showed little cultural difference; low-SPS, strong culture differences.

  1. Goal-independent mechanisms for free response generation: creative and pseudo-random performance share neural substrates.

    PubMed

    de Manzano, Örjan; Ullén, Fredrik

    2012-01-02

    To what extent free response generation in different tasks uses common and task-specific neurocognitive processes has remained unclear. Here, we investigated overlap and differences in neural activity during musical improvisation and pseudo-random response generation. Brain activity was measured using fMRI in a group of professional classical pianists, who performed musical improvisation of melodies, pseudo-random key-presses and a baseline condition (sight-reading), on either two, six or twelve keys on a piano keyboard. The results revealed an extensive overlap in neural activity between the two generative conditions. Active regions included the dorsolateral and dorsomedial prefrontal cortices, inferior frontal gyrus, anterior cingulate cortex and pre-SMA. No regions showed higher activity in improvisation than in pseudo-random generation. These findings suggest that the activated regions fulfill generic functions that are utilized in different types of free generation tasks, independent of overall goal. In contrast, pseudo-random generation was accompanied by higher activity than improvisation in several regions. This presumably reflects the participants' musical expertise as well as the pseudo-random generation task's high load on attention, working memory, and executive control. The results highlight the significance of using naturalistic tasks to study human behavior and cognition. No brain activity was related to the size of the response set. We discuss that this may reflect that the musicians were able to use specific strategies for improvisation, by which there was no simple relationship between response set size and neural activity.

  2. Sexual motivation: a neural and behavioural analysis of the mechanisms underlying appetitive and copulatory responses of male rats.

    PubMed

    Everitt, B J

    1990-01-01

    Experiments investigating the neural mechanisms underlying the expression of masculine sexual behaviour are discussed in the context of the hypothesis set out by Frank Beach that suggested the existence of separate sexual arousal and performance mechanisms. The results indicate that the medial preoptic area is crucially involved in consummatory aspects of sexual behaviour: lesions and chemical manipulations of the area profoundly affect mounts, intromissions and ejaculation, but tend not to alter appetitive sexual responses. By contrast, ventral striatal dopamine-dependent mechanisms primarily affect appetitive sexual responses, measured in a variety of paradigms, but tend not to alter copulatory behaviour itself. Finally, associative mechanisms, for example those by which arbitrary environmental stimuli come to control appetitive sexual responses through their predictive association with sexual reinforcement, are shown to depend at least in part on interactions between the basolateral amygdala and dopamine-dependent events in the ventral striatum. Thus, diverse neural and behavioural procedures have revealed that separable neural mechanisms appear to be involved more or less selectively with different components of the male rat's sexual response system. It may still be useful to conceptualize separate sexual arousal and intromission/ejaculatory mechanisms when studying the neuroendocrine basis of sexual behaviour. However, a major challenge is to understand the way in which elements of the telencephalic limbic system, the striatum and preoptic area, some of which are targets for the action of sex steroids, interact to produce an integrated pattern of sexual behaviour.

  3. Functional evaluation of hemodynamic response during neural activation using optical microangiography integrated with dual-wavelength laser speckle imaging

    PubMed Central

    Qin, Jia; Shi, Lei; Wang, Hequn; Reif, Roberto; Wang, Ruikang K.

    2014-01-01

    Abstract. Evaluation of spatiotemporal hemodynamic and metabolic responses during neural activation is crucial in studying brain function. We explore the use of a noninvasive multifunctional optical imaging system to measure these responses in a mouse brain upon electrically stimulated neural activation, with the cranium left intact. The system is developed by integrating an optical microangiography (OMAG) imaging system with a dual-wavelength laser speckle imaging (DW-LSI) system. The DW-LSI, running at an image acquisition speed of ∼100  Hz, is used to extract the large-scale two-dimensional map, revealing the localized response of blood flow, hemoglobin concentration, and metabolic rate of oxygen change. Guided by DW-LSI, the OMAG is, however, used to image the response of individual blood vessels with its unique depth-resolved capability. We show that the integrated system is capable of investigating neural activation, thus is potentially valuable in the preclinical study of the mechanism of neurovascular coupling. PMID:24549439

  4. A point-process response model for spike trains from single neurons in neural circuits under optogenetic stimulation.

    PubMed

    Luo, X; Gee, S; Sohal, V; Small, D

    2016-02-10

    Optogenetics is a new tool to study neuronal circuits that have been genetically modified to allow stimulation by flashes of light. We study recordings from single neurons within neural circuits under optogenetic stimulation. The data from these experiments present a statistical challenge of modeling a high-frequency point process (neuronal spikes) while the input is another high-frequency point process (light flashes). We further develop a generalized linear model approach to model the relationships between two point processes, employing additive point-process response functions. The resulting model, point-process responses for optogenetics (PRO), provides explicit nonlinear transformations to link the input point process with the output one. Such response functions may provide important and interpretable scientific insights into the properties of the biophysical process that governs neural spiking in response to optogenetic stimulation. We validate and compare the PRO model using a real dataset and simulations, and our model yields a superior area-under-the-curve value as high as 93% for predicting every future spike. For our experiment on the recurrent layer V circuit in the prefrontal cortex, the PRO model provides evidence that neurons integrate their inputs in a sophisticated manner. Another use of the model is that it enables understanding how neural circuits are altered under various disease conditions and/or experimental conditions by comparing the PRO parameters.

  5. The abnormal in vitro response to aspirin of platelets from aspirin-sensitive asthmatics is inhibited after inhalation of nedocromil sodium but not of sodium cromoglycate.

    PubMed Central

    Marquette, C H; Joseph, M; Tonnel, A B; Vorng, H; Lassalle, P; Tsicopoulos, A; Capron, A

    1990-01-01

    1. Blood platelets from patients with aspirin-sensitive asthma (ASA) generated cytotoxic mediators in the presence of aspirin. This abnormal in vitro response to aspirin was abolished within 1 h after nedocromil sodium inhalation but not after sodium cromoglycate inhalation. 2. Platelets recovered this reactivity to aspirin by 12 hours after nedocromil sodium treatment of ASA-patients. 3. The in vitro reactivity to aspirin of ASA platelets isolated before inhalation was inhibited in the presence of serum isolated 15 and 60 min after nedocromil sodium inhalation. PMID:2161678

  6. Neural systems mediating decision-making and response inhibition for social and nonsocial stimuli in autism.

    PubMed

    Shafritz, Keith M; Bregman, Joel D; Ikuta, Toshikazu; Szeszko, Philip R

    2015-07-03

    Autism is marked by impairments in social reciprocity and communication, along with restricted, repetitive and stereotyped behaviors. Prior studies have separately investigated social processing and executive function in autism, but little is known about the brain mechanisms of cognitive control for both emotional and nonemotional stimuli. We used functional magnetic resonance imaging to identify differences in neurocircuitry between individuals with high functioning autism (HFA) and neurotypical controls during two versions of a go/no-go task: emotional (fear and happy faces) and nonemotional (English letters). During the letter task, HFA participants showed hypoactivation in the ventral prefrontal cortex. During the emotion task, happy faces elicited activation in the ventral striatum, nucleus accumbens and anterior amygdala in neurotypical, but not HFA, participants. Response inhibition for fear faces compared with happy faces recruited occipitotemporal regions in HFA, but not neurotypical, participants. In a direct contrast of emotional no-go and letter no-go blocks, HFA participants showed hyperactivation in extrastriate cortex and fusiform gyrus. Accuracy for emotional no-go trials was negatively correlated with activation in fusiform gyrus in the HFA group. These results indicate that autism is associated with abnormal processing in socioemotional brain networks, and support the theory that autism is marked by a social motivational deficit.

  7. Emotion regulation related neural predictors of cognitive behavioral therapy response in social anxiety disorder.

    PubMed

    Klumpp, Heide; Roberts, Julia; Kennedy, Amy E; Shankman, Stewart A; Langenecker, Scott A; Gross, James J; Phan, K Luan

    2017-04-03

    Social anxiety disorder (SAD) is characterized by aberrant prefrontal activity during reappraisal, an adaptive cognitive approach aimed at downregulating the automatic response evoked by a negative event. Cognitive behavioral therapy (CBT) is first-line psychotherapy for SAD, however, many remain symptomatic after treatment indicating baseline individual differences in neurofunctional activity may factor into CBT outcome. An emotion regulation strategy practiced in CBT is cognitive restructuring, a proxy for reappraisal. Therefore, neural response during reappraisal may serve as a brain-based predictor of CBT success. Prior to 12weeks of individual CBT, 34 patients with SAD completed a validated emotion regulation task during fMRI. Task instructions included 'Reappraise,' that is, use a cognitive approach to reduce affective state to a negative image, which was contrasted with looking at a negative image ('Look'). Regression results for Reappraise (vs. Look) revealed greater reduction in symptom severity was predicted by less pre-CBT activation in the dorsolateral prefrontal cortex (DLPFC). Regarding predictive validity, DLPFC significantly classified responder status. Post-hoc analysis revealed DLPFC activity, but not demographic data, baseline clinical measures, or reappraisal-related affective state during fMRI, significantly accounted for the variance in symptom reduction. Findings indicate patients with SAD are more likely to benefit from CBT if there is less pre-treatment DLPFC recruitment, a region strongly implicated in emotion regulation. Patients with reduced baseline frontal activation when reappraising negative stimuli may be especially helped by explicit cognitive interventions. Further research is necessary to establish DLPFC as a stable brain-based marker of treatment outcome.

  8. Abnormal nocturnal heart rate variability response among chronic kidney disease and dialysis patients during wakefulness and sleep

    PubMed Central

    Roumelioti, Maria-Eleni; Ranpuria, Reena; Hall, Martica; Hotchkiss, John R.; Chan, Chris T.; Unruh, Mark L.; Argyropoulos, Christos

    2010-01-01

    Background. Dialysis patients and patients with chronic kidney disease (CKD) experience a substantial risk for abnormal autonomic function and abnormal heart rate variability (HRV). It remains unknown whether HRV changes across sleep stages in patients with different severity of CKD or dialysis dependency. We hypothesized that high-frequency (HF) HRV (vagal tone) will be attenuated from wakefulness to non-rapid eye movement (NREM) and then to rapid eye movement (REM) sleep in dialysis patients as compared to patients with CKD. Methods. In-home polysomnography was performed in 95 patients with stages 4–5 CKD or end-stage renal disease (ESRD) on haemodialysis (HD) or peritoneal dialysis (PD). HRV was measured using fast Fourier transform of interbeat intervals during wakefulness and sleep. Low-frequency (LF) and HF intervals were generated. Natural logarithm HF (LNHF) and the logarithm LF/HF ratio (sympathovagal tone) were analysed by multivariable quantile regression and generalized estimating equations. Results. Of the 95 patients, 63.2% (n = 60) was male, 35.8% (n = 34) was African American and 20.4% (n = 19) was diabetic. Average age was 51.6 ± 15.1 (range 19–82). HRV variables were significantly associated with diabetic status, higher periodic limb movement indices and lower bicarbonate levels. Patients with advanced CKD did not differ from dialysis patients in their inability to increase vagal tone during sleep. During wakefulness, female gender (P = 0.05) was associated with the increases in the vagal tone. Conclusions. Patients with CKD/ESRD exhibit dysregulation of the autonomic nervous system tone manifesting as a failure to increase HRV during wakefulness and sleep. Different patient characteristics are associated with changes in HRV at different sleep stages. PMID:20466675

  9. Dissociated emergent-response system and fine-processing system in human neural network and a heuristic neural architecture for autonomous humanoid robots.

    PubMed

    Yan, Xiaodan

    2010-01-01

    The current study investigated the functional connectivity of the primary sensory system with resting state fMRI and applied such knowledge into the design of the neural architecture of autonomous humanoid robots. Correlation and Granger causality analyses were utilized to reveal the functional connectivity patterns. Dissociation was within the primary sensory system, in that the olfactory cortex and the somatosensory cortex were strongly connected to the amygdala whereas the visual cortex and the auditory cortex were strongly connected with the frontal cortex. The posterior cingulate cortex (PCC) and the anterior cingulate cortex (ACC) were found to maintain constant communication with the primary sensory system, the frontal cortex, and the amygdala. Such neural architecture inspired the design of dissociated emergent-response system and fine-processing system in autonomous humanoid robots, with separate processing units and another consolidation center to coordinate the two systems. Such design can help autonomous robots to detect and respond quickly to danger, so as to maintain their sustainability and independence.

  10. Dissociated Emergent-Response System and Fine-Processing System in Human Neural Network and a Heuristic Neural Architecture for Autonomous Humanoid Robots

    PubMed Central

    Yan, Xiaodan

    2010-01-01

    The current study investigated the functional connectivity of the primary sensory system with resting state fMRI and applied such knowledge into the design of the neural architecture of autonomous humanoid robots. Correlation and Granger causality analyses were utilized to reveal the functional connectivity patterns. Dissociation was within the primary sensory system, in that the olfactory cortex and the somatosensory cortex were strongly connected to the amygdala whereas the visual cortex and the auditory cortex were strongly connected with the frontal cortex. The posterior cingulate cortex (PCC) and the anterior cingulate cortex (ACC) were found to maintain constant communication with the primary sensory system, the frontal cortex, and the amygdala. Such neural architecture inspired the design of dissociated emergent-response system and fine-processing system in autonomous humanoid robots, with separate processing units and another consolidation center to coordinate the two systems. Such design can help autonomous robots to detect and respond quickly to danger, so as to maintain their sustainability and independence. PMID:21331371

  11. Phasic bursting pattern of postural responses may reflect internal dynamics: simulation of trunk reflexes with a neural oscillator model.

    PubMed

    Wulf, Arne; Wagner, Heiko; Wulf, Thomas; Schinowski, David; Puta, Christian; Anders, Christoph; Chong, Sook Yee

    2012-10-11

    Postural responses are usually investigated as reflexes. Several trials are averaged, and trial-to-trial variations are interpreted as noise. Several studies providing single-trial data plots revealed oscillations that may be cancelled out in averaged time series. Variations between single trials may also be interpreted as a consequence of changed dynamic properties of the neural circuitries. Therefore, we propose a Matsuoka oscillator model to describe single-trial postural responses to external perturbations. The applicability of the model was demonstrated by a comparison between simulations and experimental electromyographic (EMG) data. Vertical force perturbations of durations 0.4 s and 0.2 s were applied via a handle to 10 subjects. Handle force was used as model input, and EMG data from the external oblique muscles was compared with simulation output. Model coefficients were optimized by a least-squares algorithm. The optimization produced a good similarity between simulation and experimental data with determination coefficients of r(2)=0.7 and greater. Furthermore, as a model validation, the model coefficients were used to predict other perturbation trials with similarities between predictions and respective EMG data of about r(2)=0.45, which was in the range of trial-to-trial EMG variability. The observed oscillations are assumed to originate from the central nervous system with changes in the neural circuitries between trials. Hence, the oscillations in single trial responses which are usually regarded as noise might be generated by the dynamics of a neural oscillator.

  12. Beauty is in the belief of the beholder: cognitive influences on the neural response to facial attractiveness.

    PubMed

    Thiruchselvam, Ravi; Harper, Jessica; Homer, Abigail L

    2016-12-01

    Judgments of facial attractiveness are central to decision-making in various domains, but little is known about the extent to which they are malleable. In this study, we used EEG/ERP methods to examine two novel influences on neural and subjective responses to facial attractiveness: an observer's expectation and repetition. In each trial of our task, participants viewed either an ordinary or attractive face. To alter expectations, the faces were preceded by a peer-rating that ostensibly reflected the overall attractiveness value assigned to that face by other individuals. To examine the impact of repetition, trials were presented twice throughout the experimental session. Results showed that participants' expectations about a person's attractiveness level powerfully altered both the neural response (i.e. the late positive potential; LPP) and self-reported attractiveness ratings. Intriguingly, repetition enhanced both the LPP and self-reported attractiveness as well. Exploratory analyses further suggested that both observer expectation and repetition modulated early neural responses (i.e. the early posterior negativity; EPN) elicited by facial attractiveness. Collectively, these results highlight novel influences on a core social judgment that underlies individuals' affective lives.

  13. Beauty is in the belief of the beholder: cognitive influences on the neural response to facial attractiveness

    PubMed Central

    Thiruchselvam, Ravi; Harper, Jessica; Homer, Abigail L.

    2016-01-01

    Judgments of facial attractiveness are central to decision-making in various domains, but little is known about the extent to which they are malleable. In this study, we used EEG/ERP methods to examine two novel influences on neural and subjective responses to facial attractiveness: an observer’s expectation and repetition. In each trial of our task, participants viewed either an ordinary or attractive face. To alter expectations, the faces were preceded by a peer-rating that ostensibly reflected the overall attractiveness value assigned to that face by other individuals. To examine the impact of repetition, trials were presented twice throughout the experimental session. Results showed that participants’ expectations about a person’s attractiveness level powerfully altered both the neural response (i.e. the late positive potential; LPP) and self-reported attractiveness ratings. Intriguingly, repetition enhanced both the LPP and self-reported attractiveness as well. Exploratory analyses further suggested that both observer expectation and repetition modulated early neural responses (i.e. the early posterior negativity; EPN) elicited by facial attractiveness. Collectively, these results highlight novel influences on a core social judgment that underlies individuals’ affective lives. PMID:27522090

  14. Insights into metabolic mechanisms underlying folate-responsive neural tube defects: a minireview.

    PubMed

    Beaudin, Anna E; Stover, Patrick J

    2009-04-01

    Neural tube defects (NTDs), including anencephaly and spina bifida, arise from the failure of neurulation during early embryonic development. Neural tube defects are common birth defects with a heterogenous and multifactorial etiology with interacting genetic and environmental risk factors. Although the mechanisms resulting in failure of neural tube closure are unknown, up to 70% of NTDs can be prevented by maternal folic acid supplementation. However, the metabolic mechanisms underlying the association between folic acid and NTD pathogenesis have not been identified. This review summarizes our current understanding of the mechanisms by which impairments in folate metabolism might ultimately lead to failure of neural tube closure, with an emphasis on untangling the relative contributions of nutritional deficiency and genetic risk factors to NTD pathogenesis.

  15. Sensory Neural Responses to Ozone Exposure during Early Postnatal Development in Rat Airways

    PubMed Central

    Hunter, Dawn D.; Wu, Zhongxin; Dey, Richard D.

    2010-01-01

    Airway infections or irritant exposures during early postnatal periods may contribute to the onset of childhood asthma. The purpose of this study was to examine critical periods of postnatal airway development during which ozone (O3) exposure leads to heightened neural responses. Rats were exposed to O3 (2 ppm) or filtered air for 1 hour on specific postnatal days (PDs) between PD1 and PD29, and killed 24 hours after exposure. In a second experiment, rats were exposed to O3 on PD2–PD6, inside a proposed critical period of development, or on PD19–PD23, outside the critical period. Both groups were re-exposed to O3 on PD28, and killed 24 hours later. Airways were removed, fixed, and prepared for substance P (SP) immunocytochemistry. SP nerve fiber density (NFD) in control extrapulmonary (EXP) epithelium/lamina propria (EPLP) increased threefold, from 1% to 3.3% from PD1–PD3 through PD13–PD15, and maintained through PD29. Upon O3 exposure, SP-NFD in EXP–smooth muscle (SM) and intrapulmonary (INT)-SM increased at least twofold at PD1–PD3 through PD13–PD15 in comparison to air exposure. No change was observed at PD21–PD22 or PD28–PD29. In critical period studies, SP-NFD in the INT-SM and EXP-SM of the PD2–PD6 O3 group re-exposed to O3 on PD28 was significantly higher than that of the group exposed at PD19–PD23 and re-exposed at PD28. These findings suggest that O3-mediated changes in sensory innervation of SM are more responsive during earlier postnatal development. Enhanced responsiveness of airway sensory nerves may be a contributing mechanism of increased susceptibility to environmental exposures observed in human infants and children. PMID:20118220

  16. Eye movement abnormalities.

    PubMed

    Moncayo, Jorge; Bogousslavsky, Julien

    2012-01-01

    Generation and control of eye movements requires the participation of the cortex, basal ganglia, cerebellum and brainstem. The signals of this complex neural network finally converge on the ocular motoneurons of the brainstem. Infarct or hemorrhage at any level of the oculomotor system (though more frequent in the brain-stem) may give rise to a broad spectrum of eye movement abnormalities (EMAs). Consequently, neurologists and particularly stroke neurologists are routinely confronted with EMAs, some of which may be overlooked in the acute stroke setting and others that, when recognized, may have a high localizing value. The most complex EMAs are due to midbrain stroke. Horizontal gaze disorders, some of them manifesting unusual patterns, may occur in pontine stroke. Distinct varieties of nystagmus occur in cerebellar and medullary stroke. This review summarizes the most representative EMAs from the supratentorial level to the brainstem.

  17. Comparison of gene expression profiles and responses to zinc chloride among inter- and intraspecific hybrids with growth abnormalities in wheat and its relatives.

    PubMed

    Takamatsu, Kiyofumi; Iehisa, Julio C M; Nishijima, Ryo; Takumi, Shigeo

    2015-07-01

    Hybrid necrosis is a well-known reproductive isolation mechanism in plant species, and an autoimmune response is generally considered to trigger hybrid necrosis through epistatic interaction between disease resistance-related genes in hybrids. In common wheat, the complementary Ne1 and Ne2 genes control hybrid necrosis, defined as type I necrosis. Two other types of hybrid necrosis (type II and type III) have been observed in interspecific hybrids between tetraploid wheat and Aegilops tauschii. Another type of hybrid necrosis, defined here as type IV necrosis, has been reported in F1 hybrids between Triticum urartu and some accessions of Triticum monococcum ssp. aegilopoides. In types I, III and IV, cell death occurs gradually starting in older tissues, whereas type II necrosis symptoms occur only under low temperature. To compare comprehensive gene expression patterns of hybrids showing growth abnormalities, transcriptome analysis of type I and type IV necrosis was performed using a wheat 38k oligo-DNA microarray. Defense-related genes including many WRKY transcription factor genes were dramatically up-regulated in plants showing type I and type IV necrosis, similarly to other known hybrid abnormalities, suggesting an association with an autoimmune response. Reactive oxygen species generation and necrotic cell death were effectively inhibited by ZnCl2 treatment in types I, III and IV necrosis, suggesting a significant association of Ca(2+) influx in upstream signaling of necrotic cell death in wheat hybrid necrosis.

  18. Response inhibition results in the emotional devaluation of faces: neural correlates as revealed by fMRI.

    PubMed

    Doallo, Sonia; Raymond, Jane E; Shapiro, Kimron L; Kiss, Monika; Eimer, Martin; Nobre, Anna C

    2012-08-01

    Although it is well established that prior experience with faces determines their subsequent social-emotional evaluation, recent work shows that top-down inhibitory mechanisms, including response inhibition, can lead to social devaluation after even a single, brief exposure. These rapidly induced effects indicate interplay among perceptual, attentional, response-selection and social-emotional networks; yet, the brain mechanisms underlying this are not well understood. This study used functional magnetic resonance imaging (fMRI) to investigate the neural mechanism mediating the relationship between inhibitory control and emotional devaluation. Participants performed two tasks: (i) a Go/No-Go task in response to faces and (ii) a trustworthiness rating task involving the previously seen faces. No-Go faces were rated as significantly less trustworthy than Go faces. By examining brain activations during Task 1, behavioral measures and brain activations obtained in Task 2 could be predicted. Specifically, activity in brain areas during Task 1 associated with (i) executive control and response suppression (i.e. lateral prefrontal cortex) and (ii) affective responses and value representation (i.e. orbitofrontal cortex), systematically covaried with behavioral ratings and amygdala activity obtained during Task 2. The present findings offer insights into the neural mechanisms linking inhibitory processes to affective responses.

  19. Prenatal cocaine exposure and adolescent neural responses to appetitive and stressful stimuli.

    PubMed

    Yip, Sarah W; Potenza, Elise B; Balodis, Iris M; Lacadie, Cheryl M; Sinha, Rajita; Mayes, Linda C; Potenza, Marc N

    2014-11-01

    Preclinical research has demonstrated the effects of prenatal cocaine exposure (PCE) on brain regions involved in emotional regulation, motivational control, and addiction vulnerability-eg, the ventral striatum (VS), anterior cingulate (ACC), and prefrontal cortex (PFC). However, little is known about the function of these regions in human adolescents with PCE. Twenty-two adolescents with PCE and 22 age-, gender-, and IQ-matched non-cocaine exposed (NCE) adolescents underwent functional magnetic resonance imaging (fMRI) during exposure to individually personalized neutral/relaxing, stressful, and favorite-food cues. fMRI data were compared using group-level two-tailed t-tests in the BioImage Suite. In comparison with NCE adolescents, PCE adolescents had reduced activity within cortical and subcortical brain regions, including the VS, ACC, and medial and dorslolateral PFC during exposure to favorite-food cues but did not differ in neural responses to stress cues. Subjective food craving was inversely related to dorsolateral PFC activation among PCE adolescents. Among PCE adolescents, subjective anxiety ratings correlated inversely with activations in the orbitofrontal cortex and brainstem during the stress condition and with ACC, dorsolateral PFC, and hippocampus activity during the neutral-relaxing condition. Thus adolescents with PCE display hypoactivation of brain regions involved in appetitive processing, with subjective intensities of craving and anxiety correlating inversely with extent of activation. These findings suggest possible mechanisms by which PCE might predispose to the development of addictions and related disorders, eg, substance-use disorders and binge-eating.

  20. Timescale of silver nanoparticle transformation in neural cell cultures impacts measured cell response

    NASA Astrophysics Data System (ADS)

    Hume, Stephanie L.; Chiaramonti, Ann N.; Rice, Katherine P.; Schwindt, Rani K.; MacCuspie, Robert I.; Jeerage, Kavita M.

    2015-07-01

    Both serum protein concentration and ionic strength are important factors in nanoparticle transformation within cell culture environments. However, silver nanoparticles are not routinely tracked at their working concentration in the specific medium used for in vitro toxicology studies. Here we evaluated the transformation of electrostatically stabilized citrate nanoparticles (C-AgNPs) and sterically stabilized polyvinylpyrrolidone nanoparticles (PVP-AgNPs) in a low-serum ( 0.2 mg/mL bovine serum albumin) culture medium, while measuring the response of rat cortex neural progenitor cells, which differentiate in this culture environment. After 24 h, silver nanoparticles at concentrations up to 10 µg/mL did not affect adenosine triphosphate levels, whereas silver ions decreased adenosine triphosphate levels at concentrations of 1.1 µg/mL or higher. After 240 h, both silver nanoparticles, as well as silver ion, unambiguously decreased adenosine triphosphate levels at concentrations of 1 and 1.1 µg/mL, respectively, suggesting particle dissolution. Particle transformation was investigated in 1:10 diluted, 1:2 diluted, or undiluted differentiation medium, all having an identical protein concentration, to separate the effect of serum protein stabilization from ionic strength destabilization. Transmission electron microscopy images indicated that particles in 1:10 medium were not surrounded by proteins, whereas particles became clustered within a non-crystalline protein matrix after 24 h in 1:2 medium and at 0 h in undiluted medium. Despite evidence for a protein corona, particles were rapidly destabilized by high ionic strength media. Polyvinylpyrrolidone increased the stability of singly dispersed particles compared to citrate ligands; however, differences were negligible after 4 h in 1:2 medium or after 1 h in undiluted medium. Thus low-serum culture environments do not provide sufficient colloidal stability for long-term toxicology studies with citrate- or

  1. Enhanced Neural Responses to Imagined Primary Rewards Predict Reduced Monetary Temporal Discounting.

    PubMed

    Hakimi, Shabnam; Hare, Todd A

    2015-09-23

    The pervasive tendency to discount the value of future rewards varies considerably across individuals and has important implications for health and well-being. Here, we used fMRI with human participants to examine whether an individual's neural representation of an imagined primary reward predicts the degree to which the value of delayed monetary payments is discounted. Because future rewards can never be experienced at the time of choice, imagining or simulating the benefits of a future reward may play a critical role in decisions between alternatives with either immediate or delayed benefits. We found that enhanced ventromedial prefrontal cortex response during imagined primary reward receipt was correlated with reduced discounting in a separate monetary intertemporal choice task. Furthermore, activity in enhanced ventromedial prefrontal cortex during reward imagination predicted temporal discounting behavior both between- and within-individual decision makers with 62% and 73% mean balanced accuracy, respectively. These results suggest that the quality of reward imagination may impact the degree to which future outcomes are discounted. Significance statement: We report a novel test of the hypothesis that an important factor influencing the discount rate for future rewards is the quality with which they are imagined or estimated in the present. Previous work has shown that temporal discounting is linked to individual characteristics ranging from general intelligence to the propensity for addiction. We demonstrate that individual differences in a neurobiological measure of primary reward imagination are significantly correlated with discounting rates for future monetary payments. Moreover, our neurobiological measure of imagination can be used to accurately predict choice behavior both between and within individuals. These results suggest that improving reward imagination may be a useful therapeutic target for individuals whose high discount rates promote

  2. Action plan for responses to abnormal conditions in Hanford Site radioactive waste tanks with high organic content. Revision 1

    SciTech Connect

    Fowler, K.D.

    1993-07-01

    This action plan describes the criteria and the organizational responsibilities required for ensuring that waste storage tanks with high organic contents are maintained in a safe condition at the Hanford Site. In addition, response actions are outlined for (1) prevention or mitigation of excessive temperatures; or (2) a material release from any waste tank with high organic content. Other response actions may be defined by Westinghouse Hanford Company Systems Engineering if a waste tank parameter goes out of specification. Trend analysis indicates the waste tank parameters have seasonal variations, but are otherwise stable.

  3. Homozygous Mutations in NEUROD1 Are Responsible for a Novel Syndrome of Permanent Neonatal Diabetes and Neurological Abnormalities

    PubMed Central

    Rubio-Cabezas, Oscar; Minton, Jayne A.L.; Kantor, Iren; Williams, Denise; Ellard, Sian; Hattersley, Andrew T.

    2010-01-01

    OBJECTIVE NEUROD1 is expressed in both developing and mature β-cells. Studies in mice suggest that this basic helix-loop-helix transcription factor is critical in the development of endocrine cell lineage. Heterozygous mutations have previously been identified as a rare cause of maturity-onset diabetes of the young (MODY). We aimed to explore the potential contribution of NEUROD1 mutations in patients with permanent neonatal diabetes. RESEARCH DESIGN AND METHODS We sequenced the NEUROD1 gene in 44 unrelated patients with permanent neonatal diabetes of unknown genetic etiology. RESULTS Two homozygous mutations in NEUROD1 (c.427_ 428del and c.364dupG) were identified in two patients. Both mutations introduced a frameshift that would be predicted to generate a truncated protein completely lacking the activating domain. Both patients had permanent diabetes diagnosed in the first 2 months of life with no evidence of exocrine pancreatic dysfunction and a morphologically normal pancreas on abdominal imaging. In addition to diabetes, they had learning difficulties, severe cerebellar hypoplasia, profound sensorineural deafness, and visual impairment due to severe myopia and retinal dystrophy. CONCLUSIONS We describe a novel clinical syndrome that results from homozygous loss of function mutations in NEUROD1. It is characterized by permanent neonatal diabetes and a consistent pattern of neurological abnormalities including cerebellar hypoplasia, learning difficulties, sensorineural deafness, and visual impairment. This syndrome highlights the critical role of NEUROD1 in both the development of the endocrine pancreas and the central nervous system in humans. PMID:20573748

  4. TRF2 dysfunction elicits DNA damage responses associated with senescence in proliferating neural cells and differentiation of neurons.

    PubMed

    Zhang, Peisu; Furukawa, Katsutoshi; Opresko, Patricia L; Xu, Xiangru; Bohr, Vilhelm A; Mattson, Mark P

    2006-04-01

    Telomeres are specialized structures at the ends of chromosomes that consist of tandem repeats of the DNA sequence TTAGGG and several proteins that protect the DNA and regulate the plasticity of the telomeres. The telomere-associated protein TRF2 (telomeric repeat binding factor 2) is critical for the control of telomere structure and function; TRF2 dysfunction results in the exposure of the telomere ends and activation of ATM (ataxia telangiectasin mutated)-mediated DNA damage response. Recent findings suggest that telomere attrition can cause senescence or apoptosis of mitotic cells, but the function of telomeres in differentiated neurons is unknown. Here, we examined the impact of telomere dysfunction via TRF2 inhibition in neurons (primary embryonic hippocampal neurons) and mitotic neural cells (astrocytes and neuroblastoma cells). We demonstrate that telomere dysfunction induced by adenovirus-mediated expression of dominant-negative TRF2 (DN-TRF2) triggers a DNA damage response involving the formation of nuclear foci containing phosphorylated histone H2AX and activated ATM in each cell type. In mitotic neural cells DN-TRF2 induced activation of both p53 and p21 and senescence (as indicated by an up-regulation of beta-galactosidase). In contrast, in neurons DN-TRF2 increased p21, but neither p53 nor beta-galactosidase was induced. In addition, TRF2 inhibition enhanced the morphological, molecular and biophysical differentiation of hippocampal neurons. These findings demonstrate divergent molecular and physiological responses to telomere dysfunction in mitotic neural cells and neurons, indicate a role for TRF2 in regulating neuronal differentiation, and suggest a potential therapeutic application of inhibition of TRF2 function in the treatment of neural tumors.

  5. Reduced neural response to reward following 7 days treatment with the cannabinoid CB1 antagonist rimonabant in healthy volunteers.

    PubMed

    Horder, Jamie; Harmer, Catherine J; Cowen, Philip J; McCabe, Ciara

    2010-09-01

    Reduced subjective experience of reward (anhedonia) is a key symptom of major depression. The anti-obesity drug and cannabinoid type 1 receptor (CB(1)) antagonist, rimonabant, is associated with significant rates of depression and anxiety in clinical use and was recently withdrawn from the market because of these adverse effects. Using a functional magnetic resonance imaging (fMRI) model of reward we hypothesized that rimonabant would impair reward processing. Twenty-two healthy participants were randomly allocated to receive rimonabant (20 mg), or placebo, for 7 d in a double-blind, parallel group design. We used fMRI to measure the neural response to rewarding (sight and/or flavour of chocolate) and aversive (sight of mouldy strawberries and/or an unpleasant strawberry taste) stimuli on the final day of drug treatment. Rimonabant reduced the neural response to chocolate stimuli in key reward areas such as the ventral striatum and the orbitofrontal cortex. Rimonabant also decreased neural responses to the aversive stimulus condition in the caudate nucleus and ventral striatum, but increased lateral orbitofrontal activations to the aversive sight and taste of strawberry condition. Our findings are the first to show that the anti-obesity drug rimonabant inhibits the neural processing of rewarding food stimuli in humans. This plausibly underlies its ability to promote weight loss, but may also indicate a mechanism for inducing anhedonia which could lead to the increased risk of depressive symptomatology seen in clinical use. fMRI may be a useful method of screening novel agents for unwanted effects on reward and associated clinical adverse reactions.

  6. Buffering social influence: neural correlates of response inhibition predict driving safety in the presence of a peer.

    PubMed

    Cascio, Christopher N; Carp, Joshua; O'Donnell, Matthew Brook; Tinney, Francis J; Bingham, C Raymond; Shope, Jean T; Ouimet, Marie Claude; Pradhan, Anuj K; Simons-Morton, Bruce G; Falk, Emily B

    2015-01-01

    Adolescence is a period characterized by increased sensitivity to social cues, as well as increased risk-taking in the presence of peers. For example, automobile crashes are the leading cause of death for adolescents, and driving with peers increases the risk of a fatal crash. Growing evidence points to an interaction between neural systems implicated in cognitive control and social and emotional context in predicting adolescent risk. We tested such a relationship in recently licensed teen drivers. Participants completed an fMRI session in which neural activity was measured during a response inhibition task, followed by a separate driving simulator session 1 week later. Participants drove alone and with a peer who was randomly assigned to express risk-promoting or risk-averse social norms. The experimentally manipulated social context during the simulated drive moderated the relationship between individual differences in neural activity in the hypothesized cognitive control network (right inferior frontal gyrus, BG) and risk-taking in the driving context a week later. Increased activity in the response inhibition network was not associated with risk-taking in the presence of a risky peer but was significantly predictive of safer driving in the presence of a cautious peer, above and beyond self-reported susceptibility to peer pressure. Individual differences in recruitment of the response inhibition network may allow those with stronger inhibitory control to override risky tendencies when in the presence of cautious peers. This relationship between social context and individual differences in brain function expands our understanding of neural systems involved in top-down cognitive control during adolescent development.

  7. Buffering Social Influence: Neural Correlates of Response Inhibition Predict Driving Safety in the Presence of a Peer

    PubMed Central

    Cascio, Christopher N.; Carp, Joshua; O'Donnell, Matthew Brook; Tinney, Francis J.; Bingham, C. Raymond; Shope, Jean T.; Ouimet, Marie Claude; Pradhan, Anuj K.; Simons-Morton, Bruce G.; Falk, Emily B.

    2016-01-01

    Adolescence is a period characterized by increased sensitivity to social cues, as well as increased risk-taking in the presence of peers. For example, automobile crashes are the leading cause of death for adolescents, and driving with peers increases the risk of a fatal crash. Growing evidence points to an interaction between neural systems implicated in cognitive control and social and emotional context in predicting adolescent risk. We tested such a relationship in recently licensed teen drivers. Participants completed an fMRI session in which neural activity was measured during a response inhibition task, followed by a separate driving simulator session 1 week later. Participants drove alone and with a peer who was randomly assigned to express risk-promoting or risk-averse social norms. The experimentally manipulated social context during the simulated drive moderated the relationship between individual differences in neural activity in the hypothesized cognitive control network (right inferior frontal gyrus, BG) and risk-taking in the driving context a week later. Increased activity in the response inhibition network was not associated with risk-taking in the presence of a risky peer but was significantly predictive of safer driving in the presence of a cautious peer, above and beyond self-reported susceptibility to peer pressure. Individual differences in recruitment of the response inhibition network may allow those with stronger inhibitory control to override risky tendencies when in the presence of cautious peers. This relationship between social context and individual differences in brain function expands our understanding of neural systems involved in top–down cognitive control during adolescent development. PMID:25100217

  8. Neural correlates of emotional processing in depression: changes with cognitive behavioral therapy and predictors of treatment response.

    PubMed

    Ritchey, Maureen; Dolcos, Florin; Eddington, Kari M; Strauman, Timothy J; Cabeza, Roberto

    2011-05-01

    Major depressive disorder (MDD) is characterized by the presence of disturbances in emotional processing. However, the neural correlates of these alterations, and how they may be affected by therapeutic interventions, remain unclear. The present study addressed these issues in a preliminary investigation using functional magnetic resonance imaging (fMRI) to examine neural responses to positive, negative, and neutral pictures in unmedicated MDD patients (N = 22) versus controls (N = 14). After this initial scan, MDD patients were treated with cognitive behavioral therapy (CBT) and scanned again after treatment. Within regions that showed pre-treatment differences between patients and controls, we tested the association between pre-treatment activity and subsequent treatment response as well as activity changes from pre- to post-treatment. This study yielded three main findings. First, prior to treatment and relative to controls, patients exhibited overall reduced activity in the ventromedial prefrontal cortex (PFC), diminished discrimination between emotional and neutral items in the amygdala, caudate, and hippocampus, and enhanced responses to negative versus positive stimuli in the left anterior temporal lobe (ATL) and right dorsolateral PFC. Second, CBT-related symptom improvement in MDD patients was predicted by increased activity at baseline in ventromedial PFC as well as the valence effects in the ATL and dorsolateral PFC. Third, from pre- to post-treatment, MDD patients exhibited overall increases in ventromedial PFC activation, enhanced arousal responses in the amygdala, caudate, and hippocampus, and a reversal of valence effects in the ATL. The study was limited by the relatively small sample that was able to complete both scan sessions, as well as an inability to determine the influence of comorbid disorders within the current sample. Nevertheless, components of the neural networks corresponding to emotion processing disturbances in MDD appear to resolve

  9. Gestational naltrexone ameliorates fetal ethanol exposures enhancing effect on the postnatal behavioral and neural response to ethanol

    PubMed Central

    Youngentob, Steven L; Kent, Paul F; Youngentob, Lisa M

    2012-01-01

    The association between gestational exposure to ethanol and adolescent ethanol abuse is well established. Recent animal studies support the role of fetal ethanol experience-induced chemosensory plasticity as contributing to this observation. Previously, we established that fetal ethanol exposure, delivered through a dam’s diet throughout gestation, tuned the neural response of the peripheral olfactory system of early postnatal rats to the odor of ethanol. This occurred in conjunction with a loss of responsiveness to other odorants. The instinctive behavioral response to the odor of ethanol was also enhanced. Importantly, there was a significant contributory link between the altered response to the odor of ethanol and increased ethanol avidity when assessed in the same animals. Here, we tested whether the neural and behavioral olfactory plasticity, and their relationship to enhanced ethanol intake, is a result of the mere exposure to ethanol or whether it requires the animal to associate ethanol’s reinforcing properties with its odor attributes. In this later respect, the opioid system is important in the mediation (or modulation) of the reinforcing aspects of ethanol. To block endogenous opiates during prenatal life, pregnant rats received daily intraperitoneal administration of the opiate antagonist naltrexone from gestational day 6–21 jointly with ethanol delivered via diet. Relative to control progeny, we found that gestational exposure to naltrexone ameliorated the enhanced postnatal behavioral response to the odor of ethanol and postnatal drug avidity. Our findings support the proposition that in utero ethanol-induced olfactory plasticity (and its relationship to postnatal intake) requires, at least in part, the associative pairing between ethanol’s odor quality and its reinforcing aspects. We also found suggestive evidence that fetal naltrexone ameliorated the untoward effects of gestational ethanol exposure on the neural response to non

  10. Precision Interval Estimation of the Response Surface by Means of an Integrated Algorithm of Neural Network and Linear Regression

    NASA Technical Reports Server (NTRS)

    Lo, Ching F.

    1999-01-01

    The integration of Radial Basis Function Networks and Back Propagation Neural Networks with the Multiple Linear Regression has been accomplished to map nonlinear response surfaces over a wide range of independent variables in the process of the Modem Design of Experiments. The integrated method is capable to estimate the precision intervals including confidence and predicted intervals. The power of the innovative method has been demonstrated by applying to a set of wind tunnel test data in construction of response surface and estimation of precision interval.

  11. Application of response surface methodology and artificial neural network methods in modelling and optimization of biosorption process.

    PubMed

    Witek-Krowiak, Anna; Chojnacka, Katarzyna; Podstawczyk, Daria; Dawiec, Anna; Pokomeda, Karol

    2014-05-01

    A review on the application of response surface methodology (RSM) and artificial neural networks (ANN) in biosorption modelling and optimization is presented. The theoretical background of the discussed methods with the application procedure is explained. The paper describes most frequently used experimental designs, concerning their limitations and typical applications. The paper also presents ways to determine the accuracy and the significance of model fitting for both methodologies described herein. Furthermore, recent references on biosorption modelling and optimization with the use of RSM and the ANN approach are shown. Special attention was paid to the selection of factors and responses, as well as to statistical analysis of the modelling results.

  12. Regional neural response differences in the determination of faces or houses positioned in a wide visual field.

    PubMed

    Wang, Bin; Yan, Tianyi; Wu, Jinglong; Chen, Kewei; Imajyo, Satoshi; Ohno, Seiichiro; Kanazawa, Susumu

    2013-01-01

    In human visual cortex, the primary visual cortex (V1) is considered to be essential for visual information processing; the fusiform face area (FFA) and parahippocampal place area (PPA) are considered as face-selective region and places-selective region, respectively. Recently, a functional magnetic resonance imaging (fMRI) study showed that the neural activity ratios between V1 and FFA were constant as eccentricities increasing in central visual field. However, in wide visual field, the neural activity relationships between V1 and FFA or V1 and PPA are still unclear. In this work, using fMRI and wide-view present system, we tried to address this issue by measuring neural activities in V1, FFA and PPA for the images of faces and houses aligning in 4 eccentricities and 4 meridians. Then, we further calculated ratio relative to V1 (RRV1) as comparing the neural responses amplitudes in FFA or PPA with those in V1. We found V1, FFA, and PPA showed significant different neural activities to faces and houses in 3 dimensions of eccentricity, meridian, and region. Most importantly, the RRV1s in FFA and PPA also exhibited significant differences in 3 dimensions. In the dimension of eccentricity, both FFA and PPA showed smaller RRV1s at central position than those at peripheral positions. In meridian dimension, both FFA and PPA showed larger RRV1s at upper vertical positions than those at lower vertical positions. In the dimension of region, FFA had larger RRV1s than PPA. We proposed that these differential RRV1s indicated FFA and PPA might have different processing strategies for encoding the wide field visual information from V1. These different processing strategies might depend on the retinal position at which faces or houses are typically observed in daily life. We posited a role of experience in shaping the information processing strategies in the ventral visual cortex.

  13. Abnormal responses of electronic pocket dosimeters caused by high frequency electromagnetic fields emitted from digital cellular telephones.

    PubMed

    Deji, Shizuhiko; Nishizawa, Kunihide

    2005-09-01

    High frequency electromagnetic fields emitted from digital cellular telephones (cell phones) occasionally cause abnormally high and erroneous indicated dose readings on electronic pocket dosimeters (EPDs). Electric field strength distribution around a cell phone transmitting 1.5 GHz band with a maximum power of 0.8 W was analyzed by using an isotropic probe with tri-axial dipole antennas. Five types of EPDs were exposed to the fields for 50 s under configurations relative to the cell phone. The electric field distribution expanded around the phone's antenna and had a maximum electric field strength of 36.5 +/- 0.3 V m(-1). The cell phone gave rise to erroneous indicated dose readings on four out of five EPDs. The maximum value of erroneous indicated dosage for 50 s reached 1,283 microSv, which was about 2.6% of the annual effective dose limit of 50 mSv. The electromagnetic susceptibility of the EPDs was higher in the sections where the semiconductor detectors or electric circuit boards were located. The distance required to prevent electromagnetic interference differed for each EPD and ranged from 2.0 to 21.0 cm from the cell phone. The electric and magnetic field immunity levels of the EPDs varied from 9.2 V m(-1) to greater than 37.6 V m(-1), and from 0.03 A m(-1) to greater than 0.51 A m(-1). The EPDs displayed erroneous dose readings during exposure but recovered their normal performance after the cell phone ceased transmitting. The electromagnetic immunity levels of the EPDs were either equal to or greater than the IEC-standard. The immunity levels should be enhanced greater than the IEC-standard from the standpoint of radiation protection. The simplest and most reliable measure to prevent potential malfunction is to prohibit the radiation workers from carrying cell phones to their workplace.

  14. Defects responsible for abnormal n-type conductivity in Ag-excess doped PbTe thermoelectrics

    SciTech Connect

    Ryu, Byungki Lee, Jae Ki; Lee, Ji Eun; Joo, Sung-Jae; Kim, Bong-Seo; Min, Bok-Ki; Lee, Hee-Woong; Park, Su-Dong; Oh, Min-Wook

    2015-07-07

    Density functional calculations have been performed to investigate the role of Ag defects in PbTe thermoelectric materials. Ag-defects can be either donor, acceptor, or isovalent neutral defect. When Ag is heavily doped in PbTe, the neutral (Ag-Ag) dimer defect at Pb-site is formed and the environment changes to the Pb-rich/Te-poor condition. Under Pb-rich condition, the ionized Ag-interstitial defect (Ag{sub I}{sup +}) becomes the major donor. The formation energy of Ag{sub I}{sup +} is smaller than other native and Ag-related defects. Also it is found that Ag{sub I}{sup +} is an effective dopant. There is no additional impurity state near the band gap and the conduction band minimum. The charge state of Ag{sub I}{sup +} defect is maintained even when the Fermi level is located above the conduction band minimum. The diffusion constant of Ag{sub I}{sup +} is calculated based on the temperature dependent Fermi level, formation energy, and migration energy. When T > 550 K, the diffusion length of Ag within a few minutes is comparable to the grain size of the polycrystalline PbTe, implying that Ag is dissolved into PbTe and this donor defect is distributed over the whole lattice in Ag-excess doped polycrystalline PbTe. The predicted solubility of Ag{sub I}{sup +} well explains the increased electron carrier concentration and electrical conductivity reported in Ag-excess doped polycrystalline PbTe at T = 450–750 K [Pei et al., Adv. Energy Mater. 1, 291 (2011)]. In addition, we suggest that this abnormal doping behavior is also found for Au-doped PbTe.

  15. Where does brain neural activation in aesthetic responses to visual art occur? Meta-analytic evidence from neuroimaging studies.

    PubMed

    Boccia, M; Barbetti, S; Piccardi, L; Guariglia, C; Ferlazzo, F; Giannini, A M; Zaidel, D W

    2016-01-01

    Here we aimed at finding the neural correlates of the general aspect of visual aesthetic experience (VAE) and those more strictly correlated with the content of the artworks. We applied a general activation likelihood estimation (ALE) meta-analysis to 47 fMRI experiments described in 14 published studies. We also performed four separate ALE analyses in order to identify the neural substrates of reactions to specific categories of artworks, namely portraits, representation of real-world-visual-scenes, abstract paintings, and body sculptures. The general ALE revealed that VAE relies on a bilateral network of areas, and the individual ALE analyses revealed different maximal activation for the artworks' categories as function of their content. Specifically, different content-dependent areas of the ventral visual stream are involved in VAE, but a few additional brain areas are involved as well. Thus, aesthetic-related neural responses to art recruit widely distributed networks in both hemispheres including content-dependent brain areas of the ventral visual stream. Together, the results suggest that aesthetic responses are not independent of sensory, perceptual, and cognitive processes.

  16. Failure to modulate neural response to increased task demand in mild Alzheimer's disease: fMRI study of visuospatial processing.

    PubMed

    Vannini, Patrizia; Lehmann, Christoph; Dierks, Thomas; Jann, Kay; Viitanen, Matti; Wahlund, Lars-Olof; Almkvist, Ove

    2008-09-01

    Alzheimer's disease (AD) is characterized by disturbances of visuospatial cognition. Given that these impairments are closely related to metabolic and neuropathological changes, our study aimed to investigate the functional competency of brain regions in the visuospatial networks responsible for early clinical symptoms in AD using event-related functional magnetic resonance imaging (fMRI). Participants (13AD patients with mild symptoms and 13 age- and education-matched controls) performed an angle discrimination task with varying task demand. Using a novel approach that modeled the dependency of the blood oxygenation level-dependent (BOLD) signal on the subject's reaction time allowed us to investigate task demand-dependent signal changes between the groups. Both groups demonstrated overlapping neural networks engaged in angle discrimination, including the parieto-occipital and frontal regions. In several network regions, AD patients showed a significantly weaker and sometimes no BOLD signal due to increased task demand compared with controls, demonstrating failure to modulate the neural response to increased task demand. A general task demand-independent increase of activation in AD patients compared with controls was found in right middle temporal gyrus. This latter finding may indicate an attempt to compensate for dysfunctional areas in the dorsal visual pathway. These results confirm deficits in visuospatial abilities, which occur early in AD, and offer new insights into the neural mechanisms underlying this impairment.

  17. Neural responses to visual food cues according to weight status: a systematic review of functional magnetic resonance imaging studies.

    PubMed

    Pursey, Kirrilly M; Stanwell, Peter; Callister, Robert J; Brain, Katherine; Collins, Clare E; Burrows, Tracy L

    2014-01-01

    Emerging evidence from recent neuroimaging studies suggests that specific food-related behaviors contribute to the development of obesity. The aim of this review was to report the neural responses to visual food cues, as assessed by functional magnetic resonance imaging (fMRI), in humans of differing weight status. Published studies to 2014 were retrieved and included if they used visual food cues, studied humans >18 years old, reported weight status, and included fMRI outcomes. Sixty studies were identified that investigated the neural responses of healthy weight participants (n = 26), healthy weight compared to obese participants (n = 17), and weight-loss interventions (n = 12). High-calorie food images were used in the majority of studies (n = 36), however, image selection justification was only provided in 19 studies. Obese individuals had increased activation of reward-related brain areas including the insula and orbitofrontal cortex in response to visual food cues compared to healthy weight individuals, and this was particularly evident in response to energy dense cues. Additionally, obese individuals were more responsive to food images when satiated. Meta-analysis of changes in neural activation post-weight loss revealed small areas of convergence across studies in brain areas related to emotion, memory, and learning, including the cingulate gyrus, lentiform nucleus, and precuneus. Differential activation patterns to visual food cues were observed between obese, healthy weight, and weight-loss populations. Future studies require standardization of nutrition variables and fMRI outcomes to enable more direct comparisons between studies.

  18. Neural Responses to Visual Food Cues According to Weight Status: A Systematic Review of Functional Magnetic Resonance Imaging Studies

    PubMed Central

    Pursey, Kirrilly M.; Stanwell, Peter; Callister, Robert J.; Brain, Katherine; Collins, Clare E.; Burrows, Tracy L.

    2014-01-01

    Emerging evidence from recent neuroimaging studies suggests that specific food-related behaviors contribute to the development of obesity. The aim of this review was to report the neural responses to visual food cues, as assessed by functional magnetic resonance imaging (fMRI), in humans of differing weight status. Published studies to 2014 were retrieved and included if they used visual food cues, studied humans >18 years old, reported weight status, and included fMRI outcomes. Sixty studies were identified that investigated the neural responses of healthy weight participants (n = 26), healthy weight compared to obese participants (n = 17), and weight-loss interventions (n = 12). High-calorie food images were used in the majority of studies (n = 36), however, image selection justification was only provided in 19 studies. Obese individuals had increased activation of reward-related brain areas including the insula and orbitofrontal cortex in response to visual food cues compared to healthy weight individuals, and this was particularly evident in response to energy dense cues. Additionally, obese individuals were more responsive to food images when satiated. Meta-analysis of changes in neural activation post-weight loss revealed small areas of convergence across studies in brain areas related to emotion, memory, and learning, including the cingulate gyrus, lentiform nucleus, and precuneus. Differential activation patterns to visual food cues were observed between obese, healthy weight, and weight-loss populations. Future studies require standardization of nutrition variables and fMRI outcomes to enable more direct comparisons between studies. PMID:25988110

  19. Structural and behavioral correlates of abnormal encoding of money value in the sensorimotor striatum in cocaine addiction.

    PubMed

    Konova, Anna B; Moeller, Scott J; Tomasi, Dardo; Parvaz, Muhammad A; Alia-Klein, Nelly; Volkow, Nora D; Goldstein, Rita Z

    2012-10-01

    Abnormalities in frontostriatal systems are thought to be central to the pathophysiology of addiction, and may underlie the maladaptive processing of the highly generalizable reinforcer, money. Although abnormal frontostriatal structure and function have been observed in individuals addicted to cocaine, it is less clear how individual variability in brain structure is associated with brain function to influence behavior. Our objective was to examine frontostriatal structure and neural processing of money value in chronic cocaine users and closely matched healthy controls. A reward task that manipulated different levels of money was used to isolate neural activity associated with money value. Gray matter volume measures were used to assess frontostriatal structure. Our results indicated that cocaine users had an abnormal money value signal in the sensorimotor striatum (right putamen/globus pallidus) that was negatively associated with accuracy adjustments to money and was more pronounced in individuals with more severe use. In parallel, group differences were also observed in both the function and gray matter volume of the ventromedial prefrontal cortex; in the cocaine users, the former was directly associated with response to money in the striatum. These results provide strong evidence for abnormalities in the neural mechanisms of valuation in addiction and link these functional abnormalities with deficits in brain structure. In addition, as value signals represent acquired associations, their abnormal processing in the sensorimotor striatum, a region centrally implicated in habit formation, could signal disadvantageous associative learning in cocaine addiction.

  20. Structural and behavioral correlates of abnormal encoding of money value in the sensorimotor striatum in cocaine addiction

    PubMed Central

    Konova, Anna B.; Moeller, Scott J.; Tomasi, Dardo; Parvaz, Muhammad A.; Alia-Klein, Nelly; Volkow, Nora D.; Goldstein, Rita Z.

    2012-01-01

    Abnormalities in frontostriatal systems are thought to be central to the pathophysiology of addiction, and may underlie maladaptive processing of the highly generalizable reinforcer, money. Although abnormal frontostriatal structure and function have been observed in individuals addicted to cocaine, it is less clear how individual variability in brain structure is associated with brain function to influence behavior. Our objective was to examine frontostriatal structure and neural processing of money value in chronic cocaine users and closely matched healthy controls. A reward task that manipulated different levels of money was used to isolate neural activity associated with money value. Gray matter volume measures were used to assess frontostriatal structure. Our results indicated that cocaine users had an abnormal money value signal in the sensorimotor striatum (right putamen/globus pallidus) which was negatively associated with accuracy adjustments to money and was more pronounced in individuals with more severe use. In parallel, group differences were also observed in both function and gray matter volume of the ventromedial prefrontal cortex; in the cocaine users, the former was directly associated with response to money in the striatum. These results provide strong evidence for abnormalities in the neural mechanisms of valuation in addiction and link these functional abnormalities with deficits in brain structure. In addition, as value signals represent acquired associations, their abnormal processing in the sensorimotor striatum, a region centrally implicated in habit formation, could signal disadvantageous associative learning in cocaine addiction. PMID:22775285

  1. A Thalamocortical Neural Mass Model of the EEG during NREM Sleep and Its Response to Auditory Stimulation

    PubMed Central

    Ngo, Hong-Viet V.; Marshall, Lisa; Born, Jan; Martinetz, Thomas

    2016-01-01

    Few models exist that accurately reproduce the complex rhythms of the thalamocortical system that are apparent in measured scalp EEG and at the same time, are suitable for large-scale simulations of brain activity. Here, we present a neural mass model of the thalamocortical system during natural non-REM sleep, which is able to generate fast sleep spindles (12–15 Hz), slow oscillations (<1 Hz) and K-complexes, as well as their distinct temporal relations, and response to auditory stimuli. We show that with the inclusion of detailed calcium currents, the thalamic neural mass model is able to generate different firing modes, and validate the model with EEG-data from a recent sleep study in humans, where closed-loop auditory stimulation was applied. The model output relates directly to the EEG, which makes it a useful basis to develop new stimulation protocols. PMID:27584827

  2. The Power of the Like in Adolescence: Effects of Peer Influence on Neural and Behavioral Responses to Social Media.

    PubMed

    Sherman, Lauren E; Payton, Ashley A; Hernandez, Leanna M; Greenfield, Patricia M; Dapretto, Mirella

    2016-07-01

    We investigated a unique way in which adolescent peer influence occurs on social media. We developed a novel functional MRI (fMRI) paradigm to simulate Instagram, a popular social photo-sharing tool, and measured adolescents' behavioral and neural responses to likes, a quantifiable form of social endorsement and potential source of peer influence. Adolescents underwent fMRI while viewing photos ostensibly submitted to Instagram. They were more likely to like photos depicted with many likes than photos with few likes; this finding showed the influence of virtual peer endorsement and held for both neutral photos and photos of risky behaviors (e.g., drinking, smoking). Viewing photos with many (compared with few) likes was associated with greater activity in neural regions implicated in reward processing, social cognition, imitation, and attention. Furthermore, when adolescents viewed risky photos (as opposed to neutral photos), activation in the cognitive-control network decreased. These findings highlight possible mechanisms underlying peer influence during adolescence.

  3. Response of the parameters of a neural network to pseudoperiodic time series

    NASA Astrophysics Data System (ADS)

    Zhao, Yi; Weng, Tongfeng; Small, Michael

    2014-02-01

    We propose a representation plane constructed from parameters of a multilayer neural network, with the aim of characterizing the dynamical character of a learned time series. We find that fluctuation of this plane reveals distinct features of the time series. Specifically, a periodic representation plane corresponds to a periodic time series, even when contaminated with strong observational noise or dynamical noise. We present a theoretical explanation for how the neural network training algorithm adjusts parameters of this representation plane and thereby encodes the specific characteristics of the underlying system. This ability, which is intrinsic to the architecture of the neural network, can be employed to distinguish the chaotic time series from periodic counterparts. It provides a new path toward identifying the dynamics of pseudoperiodic time series. Furthermore, we extract statistics from the representation plane to quantify its character. We then validate this idea with various numerical data generated by the known periodic and chaotic dynamics and experimentally recorded human electrocardiogram data.

  4. Neural circuit changes mediating lasting brain and behavioral response to predator stress.

    PubMed

    Adamec, Robert E; Blundell, Jacqueline; Burton, Paul

    2005-01-01

    This paper reviews recent work which points to critical neural circuitry involved in lasting changes in anxiety like behavior following unprotected exposure of rats to cats (predator stress). Predator stress may increase anxiety like behavior in a variety of behavioral tests including: elevated plus maze, light dark box, acoustic startle, and social interaction. Studies of neural transmission in two limbic pathways, combined with path and covariance analysis relating physiology to behavior, suggest long term potentiation like changes in one or both of these pathways in the right hemisphere accounts for stress induced changes in all behaviors changed by predator stress except light dark box and social interaction. Findings will be discussed within the context of what is known about neural substrates activated by predator odor.

  5. Epigenetic regulation of dorsal raphe GABA(B1a) associated with isolation-induced abnormal responses to social stimulation in mice.

    PubMed

    Araki, Ryota; Hiraki, Yosuke; Nishida, Shoji; Kuramoto, Nobuyuki; Matsumoto, Kinzo; Yabe, Takeshi

    2016-02-01

    In isolation-reared mice, social encounter stimulation induces locomotor hyperactivity and activation of the dorsal raphe nucleus (DRN), suggesting that dysregulation of dorsal raphe function may be involved in abnormal behaviors. In this study, we examined the involvement of dorsal raphe GABAergic dysregulation in the abnormal behaviors of isolation-reared mice. We also studied an epigenetic mechanism underlying abnormalities of the dorsal raphe GABAergic system. Both mRNA and protein levels of GABA(B1a), a GABA(B) receptor subunit, were increased in the DRN of isolation-reared mice, compared with these levels in group-reared mice. In contrast, mRNA levels for other GABAergic system-related genes (GABA(A) receptor α1, β2 and γ2 subunits, GABA(B) receptor 1b and 2 subunits, and glutamate decarboxylase 67 and 65) were unchanged. Intra-DRN microinjection of 0.06 nmol baclofen (a GABA(B) receptor agonist) exacerbated encounter-induced hyperactivity and aggressive behavior, while microinjection of 0.3 nmol phaclofen (a GABA(B) receptor antagonist) attenuated encounter-induced hyperactivity and aggressive behavior in isolation-reared mice. Furthermore, microinjection of 0.06 nmol baclofen elicited encounter-induced hyperactivity in group-reared mice. Neither baclofen nor phaclofen affected immobility time in the forced swim test and hyperactivity in a novel environment of isolation reared mice. Bisulfite sequence analyses revealed that the DNA methylation level of the CpG island around the transcription start site (TSS) of GABA(B1a) was decreased in the DRN of isolation-reared mice. Chromatin immunoprecipitation analysis showed that histone H3 was hyperacetylated around the TSS of GABA(B1a) in the DRN of isolation-reared mice. These findings indicate that an increase in dorsal raphe GABA(B1a) expression via epigenetic regulation is associated with abnormal responses to social stimulation such as encounter-induced hyperactivity and aggressive behavior in isolation

  6. Preparation of agar nanospheres: comparison of response surface and artificial neural network modeling by a genetic algorithm approach.

    PubMed

    Zaki, Mohammad Reza; Varshosaz, Jaleh; Fathi, Milad

    2015-05-20

    Multivariate nature of drug loaded nanospheres manufacturing in term of multiplicity of involved factors makes it a time consuming and expensive process. In this study genetic algorithm (GA) and artificial neural network (ANN), two tools inspired by natural process, were employed to optimize and simulate the manufacturing process of agar nanospheres. The efficiency of GA was evaluated against the response surface methodology (RSM). The studied responses included particle size, poly dispersity index, zeta potential, drug loading and release efficiency. GA predicted greater extremum values for response factors compared to RSM. However, real values showed some deviations from predicted data. Appropriate agreement was found between ANN model predicted and real values for all five response factors with high correlation coefficients. GA was more successful than RSM in optimization and along with ANN were efficient tools in optimizing and modeling the fabrication process of drug loaded in agar nanospheres.

  7. Increased skin conductance responses and neural activity during fear conditioning are associated with a repressive coping style

    PubMed Central

    Klucken, Tim; Kruse, Onno; Schweckendiek, Jan; Stark, Rudolf

    2015-01-01

    The investigation of individual differences in coping styles in response to fear conditioning is an important issue for a better understanding of the etiology and treatment of psychiatric disorders. It has been assumed that an avoidant (repressive) coping style is characterized by increased emotion regulation efforts in context of fear stimuli as compared to a more vigilant coping style. However, no study so far has investigated the neural correlates of fear conditioning of repressors and sensitizers. In the present fMRI study, 76 participants were classified as repressors or as sensitizers and were exposed to a fear conditioning paradigm, in which the CS+ predicted electrical stimulation, while another neutral stimulus (CS−) did not. In addition, skin conductance responses (SCRs) were measured continuously. As the main findings, we found increased neural activity in repressors as compared to sensitizers in the ventromedial prefrontal cortex and the anterior cingulate cortex (ACC) during fear conditioning. In addition, elevated activity to the CS+ in amygdala, insula, occipital, and orbitofrontal cortex (OFC) as well as elevated conditioned SCRs were found in repressors. The present results demonstrate increased neural activations in structures linked to emotion down-regulation mechanisms like the ventromedial prefrontal cortex, which may reflect the increased coping effort in repressors. At the same time, repressors showed increased activations in arousal and evaluation-associated structures like the amygdala, the occipital cortex (OCC), and the OFC, which was mirrored in increased SCRs. The present results support recent assumptions about a two-process model of repression postulating a fast vigilant response to fear stimuli, and a second process associated with the down-regulation of emotional responses. PMID:26082695

  8. A system identification analysis of neural adaptation dynamics and nonlinear responses in the local reflex control of locust hind limbs.

    PubMed

    Dewhirst, Oliver P; Angarita-Jaimes, Natalia; Simpson, David M; Allen, Robert; Newland, Philip L

    2013-02-01

    Nonlinear type system identification models coupled with white noise stimulation provide an experimentally convenient and quick way to investigate the often complex and nonlinear interactions between the mechanical and neural elements of reflex limb control systems. Previous steady state analysis has allowed the neurons in such systems to be categorised by their sensitivity to position, velocity or acceleration (dynamics) and has improved our understanding of network function. These neurons, however, are known to adapt their output amplitude or spike firing rate during repetitive stimulation and this transient response may be more important than the steady state response for reflex control. In the current study previously used system identification methods are developed and applied to investigate both steady state and transient dynamic and nonlinear changes in the neural circuit responsible for controlling reflex movements of the locust hind limbs. Through the use of a parsimonious model structure and Monte Carlo simulations we conclude that key system dynamics remain relatively unchanged during repetitive stimulation while output amplitude adaptation is occurring. Whilst some evidence of a significant change was found in parts of the systems nonlinear response, the effect was small and probably of little physiological relevance. Analysis using biologically more realistic stimulation reinforces this conclusion.

  9. Neural Responses to Meaningless Pseudosigns: Evidence for Sign-Based Phonetic Processing in Superior Temporal Cortex

    ERIC Educational Resources Information Center

    Emmorey, Karen; Xu, Jiang; Braun, Allen

    2011-01-01

    To identify neural regions that automatically respond to linguistically structured, but meaningless manual gestures, 14 deaf native users of American Sign Language (ASL) and 14 hearing non-signers passively viewed pseudosigns (possible but non-existent ASL signs) and non-iconic ASL signs, in addition to a fixation baseline. For the contrast…

  10. Dissociable Patterns of Neural Activity during Response Inhibition in Depressed Adolescents with and without Suicidal Behavior

    ERIC Educational Resources Information Center

    Pan, Lisa A.; Batezati-Alves, Silvia C.; Almeida, Jorge R. C.; Segreti, AnnaMaria; Akkal, Dalila; Hassel, Stefanie; Lakdawala, Sara; Brent, David A.; Phillips, Mary L.

    2011-01-01

    Objectives: Impaired attentional control and behavioral control are implicated in adult suicidal behavior. Little is known about the functional integrity of neural circuitry supporting these processes in suicidal behavior in adolescence. Method: Functional magnetic resonance imaging was used in 15 adolescent suicide attempters with a history of…

  11. Healthy Adolescents' Neural Response to Reward: Associations with Puberty, Positive Affect, and Depressive Symptoms

    ERIC Educational Resources Information Center

    Forbes, Erika E.; Ryan, Neal D.; Phillips, Mary L.; Manuck, Stephen B.; Worthman, Carol M.; Moyles, Donna L.; Tarr, Jill A.; Sciarrillo, Samantha R.; Dahl, Ronald E.

    2010-01-01

    Objective: Changes in reward-related behavior are an important component of normal adolescent affective development. Understanding the neural underpinnings of these normative changes creates a foundation for investigating adolescence as a period of vulnerability to affective disorders, substance use disorders, and health problems. Studies of…

  12. Object Repetition Leads to Local Increases in the Temporal Coordination of Neural Responses

    PubMed Central

    Gilbert, Jessica R.; Gotts, Stephen J.; Carver, Frederick W.; Martin, Alex

    2010-01-01

    Experience with visual objects leads to later improvements in identification speed and accuracy (“repetition priming”), but generally leads to reductions in neural activity in single-cell recording studies in animals and fMRI studies in humans. Here we use event-related, source-localized MEG (ER-SAM) to evaluate the possibility that neural activity changes related to priming in occipital, temporal, and prefrontal cortex correspond to more temporally coordinated and synchronized activity, reflected in local increases in the amplitude of low-frequency activity fluctuations (i.e. evoked power) that are time-locked to stimulus onset. Subjects (N = 17) identified pictures of objects that were either novel or repeated during the session. Tests in two separate low-frequency bands (theta/alpha: 5–15 Hz; beta: 15–35 Hz) revealed increases in evoked power (5–15 Hz) for repeated stimuli in the right fusiform gyrus, with the earliest significant increases observed 100–200 ms after stimulus onset. Increases with stimulus repetition were also observed in striate/extrastriate cortex (15–35 Hz) by 200–300 ms post-stimulus, along with a trend for a similar pattern in right lateral prefrontal cortex (5–15 Hz). Our results suggest that experience-dependent reductions in neural activity may affect improved behavioral identification through more coordinated, synchronized activity at low frequencies, constituting a mechanism for more efficient neural processing with experience. PMID:20463867

  13. Contractile abnormalities and altered drug response in engineered heart tissue from Mybpc3-targeted knock-in mice.

    PubMed

    Stöhr, Andrea; Friedrich, Felix W; Flenner, Frederik; Geertz, Birgit; Eder, Alexandra; Schaaf, Sebastian; Hirt, Marc N; Uebeler, June; Schlossarek, Saskia; Carrier, Lucie; Hansen, Arne; Eschenhagen, Thomas

    2013-10-01

    Myosin-binding protein C (Mybpc3)-targeted knock-in mice (KI) recapitulate typical aspects of human hypertrophic cardiomyopathy. We evaluated whether these functional alterations can be reproduced in engineered heart tissue (EHT) and yield novel mechanistic information on the function of cMyBP-C. EHTs were generated from cardiac cells of neonatal KI, heterozygous (HET) or wild-type controls (WT) and developed without apparent morphological differences. KI had 70% and HET 20% lower total cMyBP-C levels than WT, accompanied by elevated fetal gene expression. Under standard culture conditions and spontaneous beating, KI EHTs showed more frequent burst beating than WT and occasional tetanic contractions (14/96). Under electrical stimulation (6Hz, 37°C) KI EHTs exhibited shorter contraction and relaxation times and a twofold higher sensitivity to external [Ca(2+)]. Accordingly, the sensitivity to verapamil was 4-fold lower and the response to isoprenaline or the Ca(2+) sensitizer EMD 57033 2- to 4-fold smaller. The loss of EMD effect was verified in 6-week-old KI mice in vivo. HET EHTs were apparently normal under basal conditions, but showed similarly altered contractile responses to [Ca(2+)], verapamil, isoprenaline and EMD. In contrast, drug-induced changes in intracellular Ca(2+) transients (Fura-2) were essentially normal. In conclusion, the present findings in auxotonically contracting EHTs support the idea that cMyBP-C's normal role is to suppress force generation at low intracellular Ca(2+) and stabilize the power-stroke step of the cross bridge cycle. Pharmacological testing in EHT unmasked a disease phenotype in HET. The altered drug response may be clinically relevant.

  14. Modeling dose-dependent neural processing responses using mixed effects spline models: with application to a PET study of ethanol.

    PubMed

    Guo, Ying; Bowman, F DuBois

    2008-04-01

    For functional neuroimaging studies that involve experimental stimuli measuring dose levels, e.g. of an anesthetic agent, typical statistical techniques include correlation analysis, analysis of variance or polynomial regression models. These standard approaches have limitations: correlation analysis only provides a crude estimate of the linear relationship between dose levels and brain activity; ANOVA is designed to accommodate a few specified dose levels; polynomial regression models have limited capacity to model varying patterns of association between dose levels and measured activity across the brain. These shortcomings prompt the need to develop methods that more effectively capture dose-dependent neural processing responses. We propose a class of mixed effects spline models that analyze the dose-dependent effect using either regression or smoothing splines. Our method offers flexible accommodation of different response patterns across various brain regions, controls for potential confounding factors, and accounts for subject variability in brain function. The estimates from the mixed effects spline model can be readily incorporated into secondary analyses, for instance, targeting spatial classifications of brain regions according to their modeled response profiles. The proposed spline models are also extended to incorporate interaction effects between the dose-dependent response function and other factors. We illustrate our proposed statistical methodology using data from a PET study of the effect of ethanol on brain function. A simulation study is conducted to compare the performance of the proposed mixed effects spline models and a polynomial regression model. Results show that the proposed spline models more accurately capture varying response patterns across voxels, especially at voxels with complex response shapes. Finally, the proposed spline models can be used in more general settings as a flexible modeling tool for investigating the effects of any

  15. Acute corneal epithelial debridement unmasks the corneal stromal nerve responses to ocular stimulation in rats: Implications for abnormal sensations of the eye.

    PubMed

    Hirata, Harumitsu; Mizerska, Kamila K; Dallacasagrande, Valentina A; Guaiquil, Victor H; Rosenblatt, Mark I

    2017-03-01

    It is widely accepted that the mechanisms for transducing sensory information reside in the nerve terminals. Occasionally, however, studies have appeared demonstrating that similar mechanisms may exist in the axon to which these terminals are connected. We examined this issue using the cornea where nerve terminals in the epithelial cell layers are easily accessible for debridement, leaving the underlying stromal (axonal) nerves undisturbed. In isoflurane-anesthetized rats, we recorded extracellularly from single trigeminal ganglion neurons innervating the cornea that are excited by ocular dryness and cooling: low threshold (<2 oC cooling) and high threshold (>2 oC) cold-sensitive plus dry sensitive (LT-CS+DS and HT-CS+DS) neurons, playing possible roles in tearing and ocular pain. We found that the responses in both types of neurons to dryness, wetness, and menthol stimuli were effectively abolished by the debridement, indicating that their transduction mechanisms lie in the nerve terminals. However, some responses to the cold, heat and hyperosmolar stimuli in LT-CS+DS neurons still remained. Surprisingly, the responses to heat in ~ half of the neurons were augmented after the debridement. We were also able to evoke these residual responses and follow the trajectory of the stromal nerves, which we subsequently confirmed histologically. The residual responses always disappeared when the stromal nerves were cut at the limbus, suggesting that the additional transduction mechanisms for these sensory modalities originated mostly likely in stromal nerves. The functional significance of these residual and enhanced responses from stromal nerves may be related to the abnormal sensations observed in ocular disease.

  16. Differentiating the Neural Response to Intervention in Children with Developmental Dyslexia

    ERIC Educational Resources Information Center

    Odegard, Timothy N.; Ring, Jeremiah; Smith, Stephanie; Biggan, John; Black, Jeff

    2008-01-01

    Developmental dyslexia is associated with functional abnormalities within reading areas of the brain. For some children diagnosed with dyslexia, phonologically based remediation programs appear to rehabilitate brain function in key reading areas (Shaywitz et al., Biological Psychiatry 55: 101-110, 2004; Simos et al., Neuroscience 58: 1203-1213,…

  17. The advantage of ambiguity? Enhanced neural responses to multi-stable percepts correlate with the degree of perceived instability.

    PubMed

    Dyson, Benjamin J

    2011-01-01

    Artwork can often pique the interest of the viewer or listener as a result of the ambiguity or instability contained within it. Our engagement with uncertain sensory experiences might have its origins in early cortical responses, in that perceptually unstable stimuli might preclude neural habituation and maintain activity in early sensory areas. To assess this idea, participants engaged with an ambiguous visual stimulus wherein two squares alternated with one another, in terms of simultaneously opposing vertical and horizontal locations relative to fixation (i.e., stroboscopic alternating motion; von Schiller, 1933). At each trial, participants were invited to interpret the movement of the squares in one of five ways: traditional vertical or horizontal motion, novel clockwise or counter-clockwise motion, and, a free-view condition in which participants were encouraged to switch the direction of motion as often as possible. Behavioral reports of perceptual stability showed clockwise and counter-clockwise motion to possess an intermediate level of stability compared to relatively stable vertical and horizontal motion, and, relatively unstable motion perceived during free-view conditions. Early visual evoked components recorded at parietal-occipital sites such as C1, P1, and N1 modulated as a function of visual intention. Both at a group and individual level, increased perceptual instability was related to increased negativity in all three of these early visual neural responses. Engagement with increasingly ambiguous input may partly result from the underlying exaggerated neural response to it. The study underscores the utility of combining neuroelectric recording with the presentation of perceptually multi-stable yet physically identical stimuli, in revealing brain activity associated with the purely internal process of interpreting and appreciating the sensory world that surrounds us.

  18. Comparison of neural responses to cat meows and human vowels in the anterior and posterior auditory field of awake cats.

    PubMed

    Ma, Hanlu; Qin, Ling; Dong, Chao; Zhong, Renjia; Sato, Yu

    2013-01-01

    For humans and animals, the ability to discriminate speech and conspecific vocalizations is an important physiological assignment of the auditory system. To reveal the underlying neural mechanism, many electrophysiological studies have investigated the neural responses of the auditory cortex to conspecific vocalizations in monkeys. The data suggest that vocalizations may be hierarchically processed along an anterior/ventral stream from the primary auditory cortex (A1) to the ventral prefrontal cortex. To date, the organization of vocalization processing has not been well investigated in the auditory cortex of other mammals. In this study, we examined the spike activities of single neurons in two early auditory cortical regions with different anteroposterior locations: anterior auditory field (AAF) and posterior auditory field (PAF) in awake cats, as the animals were passively listening to forward and backward conspecific calls (meows) and human vowels. We found that the neural response patterns in PAF were more complex and had longer latency than those in AAF. The selectivity for different vocalizations based on the mean firing rate was low in both AAF and PAF, and not significantly different between them; however, more vocalization information was transmitted when the temporal response profiles were considered, and the maximum transmitted information by PAF neurons was higher than that by AAF neurons. Discrimination accuracy based on the activities of an ensemble of PAF neurons was also better than that of AAF neurons. Our results suggest that AAF and PAF are similar with regard to which vocalizations they represent but differ in the way they represent these vocalizations, and there may be a complex processing stream between them.

  19. Rapid regulation of sialidase activity in response to neural activity and sialic acid removal during memory processing in rat hippocampus.

    PubMed

    Minami, Akira; Meguro, Yuko; Ishibashi, Sayaka; Ishii, Ami; Shiratori, Mako; Sai, Saki; Horii, Yuuki; Shimizu, Hirotaka; Fukumoto, Hokuto; Shimba, Sumika; Taguchi, Risa; Takahashi, Tadanobu; Otsubo, Tadamune; Ikeda, Kiyoshi; Suzuki, Takashi

    2017-04-07

    Sialidase cleaves sialic acids on the extracellular cell surface as well as inside the cell and is necessary for normal long-term potentiation (LTP) at mossy fiber-CA3 pyramidal cell synapses and for hippocampus-dependent spatial memory. Here, we investigated in detail the role of sialidase in memory processing. Sialidase activity measured with 4-methylumbelliferyl-α-d-N-acetylneuraminic acid (4MU-Neu5Ac) or 5-bromo-4-chloroindol-3-yl-α-d-N-acetylneuraminic acid (X-Neu5Ac) and Fast Red Violet LB was increased by high-K(+)-induced membrane depolarization. Sialidase activity was also increased by chemical LTP induction with forskolin and activation of BDNF signaling, non-NMDA receptors, or NMDA receptors. The increase in sialidase activity with neural excitation appears to be caused not by secreted sialidase or by an increase in sialidase expression but by a change in the subcellular localization of sialidase. Astrocytes as well as neurons are also involved in the neural activity-dependent increase in sialidase activity. Sialidase activity visualized with a benzothiazolylphenol-based sialic acid derivative (BTP3-Neu5Ac), a highly sensitive histochemical imaging probe for sialidase activity, at the CA3 stratum lucidum of rat acute hippocampal slices was immediately increased in response to LTP-inducible high-frequency stimulation on a time scale of seconds. To obtain direct evidence for sialic acid removal on the extracellular cell surface during neural excitation, the extracellular free sialic acid level in the hippocampus was monitored using in vivo microdialysis. The free sialic acid level was increased by high-K(+)-induced membrane depolarization. Desialylation also occurred during hippocampus-dependent memory formation in a contextual fear-conditioning paradigm. Our results show that neural activity-dependent desialylation by sialidase may be involved in hippocampal memory processing.

  20. Polymer Optical Fiber Sensor and the Prediction of Sensor Response Utilizing Artificial Neural Networks

    NASA Astrophysics Data System (ADS)

    Haroglu, Derya

    characteristics: reproducibility, accuracy, selectivity, aging, and resolution. Artificial neural network (ANN), a mathematical model formed by mimicking the human nervous system, was used to predict the sensor response. Qwiknet (version 2.23) software was used to develop ANNs and according to the results of Qwiknet the prediction performances for training and testing data sets were 75%, and 83.33% respectively. In this dissertation, Chapter 1 describes the worldwide plastic optical fiber (POF) and fiber optic sensor markets, and the existing textile structures used in fiber optic sensing design particularly for the applications of biomedical and structural health monitoring (SHM). Chapter 2 provides a literature review in detail on polymer optical fibers, fiber optic sensors, and occupancy sensing in the passenger seats of automobiles. Chapter 3 includes the research objectives. Chapter 4 presents the response of POF to tensile loading, bending, and cyclic tensile loading with discussion parts. Chapter 5 includes an e-mail based survey to prioritize customer needs in a Quality Function Deployment (QFD) format utilizing Analytic Hierarchy Process (AHP) and survey results. Chapter 6 describes the POF sensor design and the behavior of it under pressure. Chapter 7 provides a data analysis based on the experimental results of Chapter 6. Chapter 8 presents the summary