Determination of dopamine in pharmaceutical formulation using enhanced luminescence from europium complex

NASA Astrophysics Data System (ADS)

Wabaidur, Saikh Mohammad; ALOthman, Zeid Abdullah; Naushad, Mu.

Biologically important compound dopamine plays an important role in the central and peripheral nervous systems. Insufficient dopamine level due to the loss of dopamine producing cells may lead to disease called Schizophrenia and Parkinson's disease. Hence, a simple and fast detection of dopamine is necessary to study in the fields of neurophysiology and clinical medicine. An enhanced fluorimetric determination of dopamine in the presence of ascorbic acid is achieved using photoluminescence of europium complex, Eu(III)-dipicolinic acid. In order to obtain better responses, several operational parameters have been investigated. Under the optimum conditions, the method showed good stability and reproducibility. The application of this method for the determination of dopamine neurotransmitters was satisfactory. Linear response was found down to 3.0 × 10-7 M with limit of detection 1.0 × 10-8 M. The relative standard deviation was found to be 3.33% from 20 independent measurements for 1.0 × 10-5 M of dopamine.

Primary headache pathophysiology in children: the contribution of clinical neurophysiology.

PubMed

Pro, S; Tarantino, S; Capuano, A; Vigevano, F; Valeriani, M

2014-01-01

Although primary headaches are very prevalent also in pediatric age, most neurophysiologic studies in these diseases concerned only the adulthood. The neurophysiologic investigation of the pathophysiological mechanisms subtending migraine and tension-type headache in children and adolescents could be particularly interesting, since during the developmental age the migrainous phenotype is scarcely influenced by many environmental factors that can typically act on adult headache patients. The neurophysiologic abnormality most frequently found in adult migraineurs, that is the reduced habituation of evoked potentials, was confirmed also in migraine children, although it was shown to involve also children with tension-type headache. Some studies showed abnormalities in the maturation of brain functions in migraine children and adolescents. While the visual system maturation seems slowed in young migraineurs, the psychophysiological mechanisms subtending somatosensory spatial attention in migraine children are more similar to those of healthy adults than to those of age-matched controls. There are some still unexplored fields that will have to be subjects of future studies. The nociceptive modality, which has been investigated in adult patients with primary headaches, should be studied also in pediatric migraine. Moreover, the technique of transcranial magnetic stimulation, not yet used in young migraineurs, will possibly provide further elements about brain excitability in migraine children. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Preliminary report on aerotoxic syndrome (AS) and the need for diagnostic neurophysiological tests.

PubMed

Hale, Margaret A; Al-Seffar, Judith A

2009-09-01

Researchers have found, in studies carried out over several years, that many passengers and crew, following their recent flights in commercial jet aeroplanes, have become unwell, with a range of symptoms in common. This condition, which has not yet been officially recognised, is called Aerotoxic Syndrome (AS). It seems to be caused, primarily, by neurotoxic organophosphates contaminating the air circulating in jet cabins. Patients with such symptoms may visit their GPs, who then arrange diagnostic tests. Some of their symptoms fall within the jurisdiction of diagnostic neurophysiological investigations, but neurophysiology practitioners may be unaware of this syndrome. Until AS is officially recognised as an illness, and guidelines for diagnostic procedures established, patients requiring specific investigations may not be appropriately referred, or tests may be performed unnecessarily. This report seeks to stimulate debate within the field, and facilitate studies, if needed, to help define the diagnostic criteria.

Cannabinoids and Vanilloids in Schizophrenia: Neurophysiological Evidence and Directions for Basic Research.

PubMed

Ruggiero, Rafael N; Rossignoli, Matheus T; De Ross, Jana B; Hallak, Jaime E C; Leite, Joao P; Bueno-Junior, Lezio S

2017-01-01

Much of our knowledge of the endocannabinoid system in schizophrenia comes from behavioral measures in rodents, like prepulse inhibition of the acoustic startle and open-field locomotion, which are commonly used along with neurochemical approaches or drug challenge designs. Such methods continue to map fundamental mechanisms of sensorimotor gating, hyperlocomotion, social interaction, and underlying monoaminergic, glutamatergic, and GABAergic disturbances. These strategies will require, however, a greater use of neurophysiological tools to better inform clinical research. In this sense, electrophysiology and viral vector-based circuit dissection, like optogenetics, can further elucidate how exogenous cannabinoids worsen (e.g., tetrahydrocannabinol, THC) or ameliorate (e.g., cannabidiol, CBD) schizophrenia symptoms, like hallucinations, delusions, and cognitive deficits. Also, recent studies point to a complex endocannabinoid-endovanilloid interplay, including the influence of anandamide (endogenous CB 1 and TRPV 1 agonist) on cognitive variables, such as aversive memory extinction. In fact, growing interest has been devoted to TRPV 1 receptors as promising therapeutic targets. Here, these issues are reviewed with an emphasis on the neurophysiological evidence. First, we contextualize imaging and electrographic findings in humans. Then, we present a comprehensive review on rodent electrophysiology. Finally, we discuss how basic research will benefit from further combining psychopharmacological and neurophysiological tools.

BAEP and E.M.G. changes from whiplash injuries.

PubMed

Serra, L L; Gallicchio, B; Serra, F P; Grillo, G; Ferrari, M

1994-12-01

The frequent negativity of neuroradiological changes after neck injury despite the constant complaints (neck pain and stiffness, limited neck movements, arm pains) experienced after a motor vehicle crash has led us to verify the diagnostic and prognostic validity of different neurophysiological tests in these patients. To this aim 120 young patients (67 females and 53 males) referred for a whiplash syndrome aged 18-31 years without neuroradiological abnormalities have been submitted to EMG and BAEP studies immediately after the traffic accident and after six months. Constant slowing of median MNCV and SNCV and ulnar SNCV without changes in morphology, amplitude and duration of MAP and SAP have been observed in 92 patients, with persistent abnormalities in 64 cases after six months. Increase in I-III or I-V interpeak interval of BAEP have been observed unilaterally in 45 patients and bilaterally in 32 ones without changes in absolute latencies and V/I amplitude ratio, with persistence of such abnormalities in 31 and 16 patients respectively after six months. Simultaneous abnormalities of all neurophysiological tests have been observed in 31 patients, with unmodified recordings after six months in 24 patients. The above findings could be accounted for subtle cerebral lesions and a possible damage to brain stem structures as claimed by Ettlin et al. (1992). The usefulness of the above proposed neurophysiological tests in assessment of asymptomatic dysfunction of central motor and sensory pathways in whiplash injuries is discussed.

Neurophysiological model of tinnitus: dependence of the minimal masking level on treatment outcome.

PubMed

Jastreboff, P J; Hazell, J W; Graham, R L

1994-11-01

Validity of the neurophysiological model of tinnitus (Jastreboff, 1990), outlined in this paper, was tested on data from multicenter trial of tinnitus masking (Hazell et al., 1985). Minimal masking level, intensity match of tinnitus, and the threshold of hearing have been evaluated on a total of 382 patients before and after 6 months of treatment with maskers, hearing aids, or combination devices. The data has been divided into categories depending on treatment outcome and type of approach used. Results of analysis revealed that: i) the psychoacoustical description of tinnitus does not possess a predictive value for the outcome of the treatment; ii) minimal masking level changed significantly depending on the treatment outcome, decreasing on average by 5.3 dB in patients reporting improvement, and increasing by 4.9 dB in those whose tinnitus remained the same or worsened; iii) 73.9% of patients reporting improvement had their minimal masking level decreased as compared with 50.5% for patients not showing improvement, which is at the level of random change; iv) the type of device used has no significant impact on the treatment outcome and minimal masking level change; v) intensity match and threshold of hearing did not exhibit any significant changes which can be related to treatment outcome. These results are fully consistent with the neurophysiological interpretation of mechanisms involved in the phenomenon of tinnitus and its alleviation.

W. Grey Walter, pioneer in the electroencephalogram, robotics, cybernetics, artificial intelligence.

PubMed

Bladin, Peter F

2006-02-01

With the announcement by William Lennox at the 1935 London International Neurology Congress of the use of electroencephalography in the study of epilepsy, it became evident that a new and powerful technique for the investigation of seizures had been discovered. William Grey Walter, a young researcher finishing his post-graduate studies at Cambridge, was selected to construct and study the EEG in clinical neurology at the Maudsley Hospital, London. His hugely productive pioneering career in the use of EEG would eventually lead to groundbreaking work in other fields --the emerging sciences of robotics, cybernetics, and early work in artificial intelligence. In this historical note his pioneering work in the fields of clinical neurophysiology is documented, both in the areas of epileptology and tumour detection. His landmark contributions to clinical neurophysiology are worthy of documentation.

Cannabinoids and Vanilloids in Schizophrenia: Neurophysiological Evidence and Directions for Basic Research

PubMed Central

Ruggiero, Rafael N.; Rossignoli, Matheus T.; De Ross, Jana B.; Hallak, Jaime E. C.; Leite, Joao P.; Bueno-Junior, Lezio S.

2017-01-01

Much of our knowledge of the endocannabinoid system in schizophrenia comes from behavioral measures in rodents, like prepulse inhibition of the acoustic startle and open-field locomotion, which are commonly used along with neurochemical approaches or drug challenge designs. Such methods continue to map fundamental mechanisms of sensorimotor gating, hyperlocomotion, social interaction, and underlying monoaminergic, glutamatergic, and GABAergic disturbances. These strategies will require, however, a greater use of neurophysiological tools to better inform clinical research. In this sense, electrophysiology and viral vector-based circuit dissection, like optogenetics, can further elucidate how exogenous cannabinoids worsen (e.g., tetrahydrocannabinol, THC) or ameliorate (e.g., cannabidiol, CBD) schizophrenia symptoms, like hallucinations, delusions, and cognitive deficits. Also, recent studies point to a complex endocannabinoid-endovanilloid interplay, including the influence of anandamide (endogenous CB1 and TRPV1 agonist) on cognitive variables, such as aversive memory extinction. In fact, growing interest has been devoted to TRPV1 receptors as promising therapeutic targets. Here, these issues are reviewed with an emphasis on the neurophysiological evidence. First, we contextualize imaging and electrographic findings in humans. Then, we present a comprehensive review on rodent electrophysiology. Finally, we discuss how basic research will benefit from further combining psychopharmacological and neurophysiological tools. PMID:28680405

Open source tools for the information theoretic analysis of neural data.

PubMed

Ince, Robin A A; Mazzoni, Alberto; Petersen, Rasmus S; Panzeri, Stefano

2010-01-01

The recent and rapid development of open source software tools for the analysis of neurophysiological datasets consisting of simultaneous multiple recordings of spikes, field potentials and other neural signals holds the promise for a significant advance in the standardization, transparency, quality, reproducibility and variety of techniques used to analyze neurophysiological data and for the integration of information obtained at different spatial and temporal scales. In this review we focus on recent advances in open source toolboxes for the information theoretic analysis of neural responses. We also present examples of their use to investigate the role of spike timing precision, correlations across neurons, and field potential fluctuations in the encoding of sensory information. These information toolboxes, available both in MATLAB and Python programming environments, hold the potential to enlarge the domain of application of information theory to neuroscience and to lead to new discoveries about how neurons encode and transmit information.

Ultra-slow mechanical stimulation of olfactory epithelium modulates consciousness by slowing cerebral rhythms in humans.

PubMed

Piarulli, A; Zaccaro, A; Laurino, M; Menicucci, D; De Vito, A; Bruschini, L; Berrettini, S; Bergamasco, M; Laureys, S; Gemignani, A

2018-04-26

The coupling between respiration and neural activity within olfactory areas and hippocampus has recently been unambiguously demonstrated, its neurophysiological basis sustained by the well-assessed mechanical sensitivity of the olfactory epithelium. We herein hypothesize that this coupling reverberates to the whole brain, possibly modulating the subject's behavior and state of consciousness. The olfactory epithelium of 12 healthy subjects was stimulated with periodical odorless air-delivery (frequency 0.05 Hz, 8 s on, 12 off). Cortical electrical activity (High Density-EEG) and perceived state of consciousness have been studied. The stimulation induced i) an enhancement of delta-theta EEG activity over the whole cortex mainly involving the Limbic System and Default Mode Network structures, ii) a reversal of the overall information flow directionality from wake-like postero-anterior to NREM sleep-like antero-posterior, iii) the perception of having experienced an Altered State of Consciousness. These findings could shed further light via a neurophenomenological approach on the links between respiration, cerebral activity and subjective experience, suggesting a plausible neurophysiological basis for interpreting altered states of consciousness induced by respiration-based meditative practices.

Neurophysiological mechanisms involved in language learning in adults

PubMed Central

Rodríguez-Fornells, Antoni; Cunillera, Toni; Mestres-Missé, Anna; de Diego-Balaguer, Ruth

2009-01-01

Little is known about the brain mechanisms involved in word learning during infancy and in second language acquisition and about the way these new words become stable representations that sustain language processing. In several studies we have adopted the human simulation perspective, studying the effects of brain-lesions and combining different neuroimaging techniques such as event-related potentials and functional magnetic resonance imaging in order to examine the language learning (LL) process. In the present article, we review this evidence focusing on how different brain signatures relate to (i) the extraction of words from speech, (ii) the discovery of their embedded grammatical structure, and (iii) how meaning derived from verbal contexts can inform us about the cognitive mechanisms underlying the learning process. We compile these findings and frame them into an integrative neurophysiological model that tries to delineate the major neural networks that might be involved in the initial stages of LL. Finally, we propose that LL simulations can help us to understand natural language processing and how the recovery from language disorders in infants and adults can be accomplished. PMID:19933142

A physiologic role for serotonergic transmission in adult rat taste buds.

PubMed

Jaber, Luc; Zhao, Fang-li; Kolli, Tamara; Herness, Scott

2014-01-01

Of the multiple neurotransmitters and neuropeptides expressed in the mammalian taste bud, serotonin remains both the most studied and least understood. Serotonin is expressed in a subset of taste receptor cells that form synapses with afferent nerve fibers (type III cells) and was once thought to be essential to neurotransmission (now understood as purinergic). However, the discovery of the 5-HT1A serotonin receptor in a subset of taste receptor cells paracrine to type III cell suggested a role in cell-to-cell communication during the processing of taste information. Functional data describing this role are lacking. Using anatomical and neurophysiological techniques, this study proposes a modulatory role for serotonin during the processing of taste information. Double labeling immunocytochemical and single cell RT-PCR technique experiments documented that 5-HT1A-expressing cells co-expressed markers for type II cells, cells which express T1R or T2R receptors and release ATP. These cells did not co-express type III cells markers. Neurophysiological recordings from the chorda tympani nerve, which innervates anterior taste buds, were performed prior to and during intravenous injection of a 5-HT1A receptor antagonist. These experiments revealed that serotonin facilitates processing of taste information for tastants representing sweet, sour, salty, and bitter taste qualities. On the other hand, injection of ondansetron, a 5-HT3 receptor antagonist, was without effect. Collectively, these data support the hypothesis that serotonin is a crucial element in a finely-tuned feedback loop involving the 5-HT1A receptor, ATP, and purinoceptors. It is hypothesized that serotonin facilitates gustatory signals by regulating the release of ATP through ATP-release channels possibly through phosphatidylinositol 4,5-bisphosphate resynthesis. By doing so, 5-HT1A activation prevents desensitization of post-synaptic purinergic receptors expressed on afferent nerve fibers and enhances the afferent signal. Serotonin may thus play a major modulatory role within peripheral taste in shaping the afferent taste signals prior to their transmission across gustatory nerves.

DEVELOPMENTAL HYPOTHYROIDISM ALTERS SYNAPTIC TRANSMISSION IN DENTATE GYRUS AND AREA CA1 OF HIPPOCAMPUS.

EPA Science Inventory

Hypothyroidism during critical periods of brain developmental leads to learning deficits and alterations in hippocampal structure. Neurophysiological properties of the hippocampus, however, have not been well characterized. The present study examined field potentials evoked in...

The right tool and the right place for the job: the importance of the field in experimental neurophysiology, 1880-1945.

PubMed

Muka, Samantha K

2016-09-01

This paper seeks to contribute to understandings of practice and place in the history of early American neurophysiology by exploring research with jellyfish at marine stations. Jellyfish became a particularly important research tool to experimental physiologists studying neurological subjects at the turn of the twentieth century. But their enthusiasm for the potential of this organism was constrained by its delicacy in captivity. The discovery of hardier species made experimentation at the shore possible and resulted in two epicenters of neurophysiological research on the American East Coast: the Marine Biological Laboratory and the Carnegie Institution's Dry Tortugas Laboratory. Work done in these locations had impacts on a wide range of physiological questions. These centers were short lived-researchers at the MBL eventually focused on the squid giant axon and the Tortugas lab closed after the death of Mayer-but the development of basic requirements and best practices to sustain these organisms paints an important picture of early experimental neurophysiology. Marine organisms and locations have played an integral role in the development of experimental life sciences in America. By understanding the earliest experimental research done at these locations, and the organisms that lured researchers from the campus to the coastline, we can begin to integrate marine stations into the larger historical narrative of American physiology.

Neurophysiological basis of rehabilitation of adolescent idiopathic scoliosis.

PubMed

Smania, Nicola; Picelli, Alessandro; Romano, Michele; Negrini, Stefano

2008-01-01

Knowledge on mechanisms of neurophysiological control of trunk movement and posture could help in the development of rehabilitation programs and brace treatment in adolescent idiopathic scoliosis (AIS). Reviewing up-to-date research on neurophysiology of movement and posture control with the aim of providing basis for new researches in the field of AIS rehabilitation and background understanding for clinicians engaged in management of AIS. Review of literature. We considered several neurophysiological issues relevant for AIS rehabilitation, namely, the peculiar organization of patterns of trunk muscle recruitment, the structure of the neural hardware subserving axial and arm muscle control, and the relevance of cognitive systems allowing mapping of spatial coordinates and building of body schema. We made clear the reason why trunk control is generally carried out by means of very fast, feedforward or feedback driven patterns of muscle activation which are deeply rooted in our neural control system and very difficult to modify by training. We hypothesized that augmented sensory feedback and strength exercises could be an important stage in a rehabilitation program aimed at hindering, or possibly reversing, scoliosis progression. In this context we considered bracing not only as a corrective biomechanical device but also as a tool for continuous sensory stimulation that could help awareness of body misalignment. Future research aimed at developing strategies of trunk postural control learning is essential in the rehabilitation of adolescent idiopathic scoliosis.

History of functional neurosurgery.

PubMed

Iskandar, B J; Nashold, B S

1995-01-01

Whereas in the early days of evil spirits, electric catfish, and phrenology, functional neurosurgery was based on crude observations and dogma, the progress made in neurophysiology at the turn of the century gave the field a strong scientific foundation. Subsequently, the advent of stereotaxis allowed access to deep brain regions and contributed an element of precision. Future directions include the development of frameless stereotaxy; the use of MRI-generated anatomic data, which would circumvent the serious problem of individual variations seen with standard brain atlases; the introduction of various chemicals into brain structures, in an attempt to influence neurochemically mediated disease processes; and finally, the use of the promising techniques of neural transplantation. On hearing of Penfield's intraoperative brain stimulations, Sherrington commented: "It must be great fun to have the physiological preparation speak to you." The idea of therapeutic neurophysiologic interventions is appealing, especially because many disorders show no obvious treatable pathologic cause (e.g., tumor, vascular malformation). As stereotactic technology becomes less cumbersome and more precise, more sophisticated in vivo neurophysiologic preparations become possible. In turn, as our understanding of nervous system physiology grows, our ability to understand pathophysiology and treat disease processes increases.

Neural dynamics of image representation in the primary visual cortex

PubMed Central

Yan, Xiaogang; Khambhati, Ankit; Liu, Lei; Lee, Tai Sing

2013-01-01

Horizontal connections in the primary visual cortex have been hypothesized to play a number of computational roles: association field for contour completion, surface interpolation, surround suppression, and saliency computation. Here, we argue that horizontal connections might also serve a critical role of computing the appropriate codes for image representation. That the early visual cortex or V1 explicitly represents the image we perceive has been a common assumption on computational theories of efficient coding (Olshausen and Field 1996), yet such a framework for understanding the circuitry in V1 has not been seriously entertained in the neurophysiological community. In fact, a number of recent fMRI and neurophysiological studies cast doubt on the neural validity of such an isomorphic representation (Cornelissen et al. 2006, von der Heydt et al. 2003). In this study, we investigated, neurophysiologically, how V1 neurons respond to uniform color surfaces and show that spiking activities of neurons can be decomposed into three components: a bottom-up feedforward input, an articulation of color tuning and a contextual modulation signal that is inversely proportional to the distance away from the bounding contrast border. We demonstrate through computational simulations that the behaviors of a model for image representation are consistent with many aspects of our neural observations. We conclude that the hypothesis of isomorphic representation of images in V1 remains viable and this hypothesis suggests an additional new interpretation of the functional roles of horizontal connections in the primary visual cortex. PMID:22944076

A Framework for Speech Activity Detection Using Adaptive Auditory Receptive Fields.

PubMed

Carlin, Michael A; Elhilali, Mounya

2015-12-01

One of the hallmarks of sound processing in the brain is the ability of the nervous system to adapt to changing behavioral demands and surrounding soundscapes. It can dynamically shift sensory and cognitive resources to focus on relevant sounds. Neurophysiological studies indicate that this ability is supported by adaptively retuning the shapes of cortical spectro-temporal receptive fields (STRFs) to enhance features of target sounds while suppressing those of task-irrelevant distractors. Because an important component of human communication is the ability of a listener to dynamically track speech in noisy environments, the solution obtained by auditory neurophysiology implies a useful adaptation strategy for speech activity detection (SAD). SAD is an important first step in a number of automated speech processing systems, and performance is often reduced in highly noisy environments. In this paper, we describe how task-driven adaptation is induced in an ensemble of neurophysiological STRFs, and show how speech-adapted STRFs reorient themselves to enhance spectro-temporal modulations of speech while suppressing those associated with a variety of nonspeech sounds. We then show how an adapted ensemble of STRFs can better detect speech in unseen noisy environments compared to an unadapted ensemble and a noise-robust baseline. Finally, we use a stimulus reconstruction task to demonstrate how the adapted STRF ensemble better captures the spectrotemporal modulations of attended speech in clean and noisy conditions. Our results suggest that a biologically plausible adaptation framework can be applied to speech processing systems to dynamically adapt feature representations for improving noise robustness.

Rehabilitation robots for the treatment of sensorimotor deficits: a neurophysiological perspective.

PubMed

Gassert, Roger; Dietz, Volker

2018-06-05

The past decades have seen rapid and vast developments of robots for the rehabilitation of sensorimotor deficits after damage to the central nervous system (CNS). Many of these innovations were technology-driven, limiting their clinical application and impact. Yet, rehabilitation robots should be designed on the basis of neurophysiological insights underlying normal and impaired sensorimotor functions, which requires interdisciplinary collaboration and background knowledge.Recovery of sensorimotor function after CNS damage is based on the exploitation of neuroplasticity, with a focus on the rehabilitation of movements needed for self-independence. This requires a physiological limb muscle activation that can be achieved through functional arm/hand and leg movement exercises and the activation of appropriate peripheral receptors. Such considerations have already led to the development of innovative rehabilitation robots with advanced interaction control schemes and the use of integrated sensors to continuously monitor and adapt the support to the actual state of patients, but many challenges remain. For a positive impact on outcome of function, rehabilitation approaches should be based on neurophysiological and clinical insights, keeping in mind that recovery of function is limited. Consequently, the design of rehabilitation robots requires a combination of specialized engineering and neurophysiological knowledge. When appropriately applied, robot-assisted therapy can provide a number of advantages over conventional approaches, including a standardized training environment, adaptable support and the ability to increase therapy intensity and dose, while reducing the physical burden on therapists. Rehabilitation robots are thus an ideal means to complement conventional therapy in the clinic, and bear great potential for continued therapy and assistance at home using simpler devices.This review summarizes the evolution of the field of rehabilitation robotics, as well as the current state of clinical evidence. It highlights fundamental neurophysiological factors influencing the recovery of sensorimotor function after a stroke or spinal cord injury, and discusses their implications for the development of effective rehabilitation robots. It thus provides insights on essential neurophysiological mechanisms to be considered for a successful development and clinical inclusion of robots in rehabilitation.

The Bushbaby Optic Nerve: Fiber Count and Fiber Diameter Spectrum

DTIC Science & Technology

1986-03-01

laminar organization of rece,)tive field properties in the lateral geniculate nucleus of bushbaby (Norton and Casagrande, 1982), the organization of...field properties in lateral geniculate nucleus of bushbaby (Galago cras- sicaudatus). Journal of Neurophysiology. 47(4):715-741. O’Fiaherty, J.J...employed an advanced digitized image analysis system (Carl Zeiss Inc., Videoplan Image Analysis System)* to more accurately and rapidly collect, analyze, and

BrainSnail: A dynamic information display system for the Sciences

PubMed Central

Telefont, Martin; Asaithambi, Asai

2009-01-01

Scientific reference management has become crucial in rapidly expanding fields of biology. Many of the reference management systems currently employed are reference centric and not object/process focused. BrainSnail is a reference management/knowledge representation application that tries to bridge disconnect between subject and reference in the fields of neuropharmacology, neuroanatomy and neurophysiology. BrainSnail has been developed with considering both individual researcher and research group efforts. PMID:19293992

Responses of human sensory characteristics to 532 nm pulse laser stimuli.

PubMed

Kim, Ji-Sun; Oh, Han-Byeol; Kim, A-Hee; Kim, Jun-Sik; Lee, Eun-Suk; Goh, Bong-Jun; Kim, Jae-Young; Jang, Kyungmin; Park, Jong-Rak; Chung, Soon-Cheol; Jun, Jae-Hoon

2016-04-29

Lasers are advantageous in some applications to stimulate a small target area and is used in various fields such as optogenetic, photoimmunological and neurophysiological studies. This study aims to implement a non-contact sense of touch without damaging biological tissues using laser. Various laser parameters were utilized in safety range to induce a sense of touch and investigate the human responses. With heat distribution simulation, the amount of changes in the temperature and the tendency in laser parameters of sensory stimulation were analyzed. The results showed the identified tactile responses in safety range with various laser parameters and temperature distribution for the laser stimulus was obtained through the simulation. This study can be applied to the areas of sensory receptor stimulation, neurophysiology and clinical medicine.

A Physiologic Role for Serotonergic Transmission in Adult Rat Taste Buds

PubMed Central

Jaber, Luc; Zhao, Fang-li; Kolli, Tamara; Herness, Scott

2014-01-01

Of the multiple neurotransmitters and neuropeptides expressed in the mammalian taste bud, serotonin remains both the most studied and least understood. Serotonin is expressed in a subset of taste receptor cells that form synapses with afferent nerve fibers (type III cells) and was once thought to be essential to neurotransmission (now understood as purinergic). However, the discovery of the 5-HT1A serotonin receptor in a subset of taste receptor cells paracrine to type III cell suggested a role in cell-to-cell communication during the processing of taste information. Functional data describing this role are lacking. Using anatomical and neurophysiological techniques, this study proposes a modulatory role for serotonin during the processing of taste information. Double labeling immunocytochemical and single cell RT-PCR technique experiments documented that 5-HT1A-expressing cells co-expressed markers for type II cells, cells which express T1R or T2R receptors and release ATP. These cells did not co-express type III cells markers. Neurophysiological recordings from the chorda tympani nerve, which innervates anterior taste buds, were performed prior to and during intravenous injection of a 5-HT1A receptor antagonist. These experiments revealed that serotonin facilitates processing of taste information for tastants representing sweet, sour, salty, and bitter taste qualities. On the other hand, injection of ondansetron, a 5-HT3 receptor antagonist, was without effect. Collectively, these data support the hypothesis that serotonin is a crucial element in a finely-tuned feedback loop involving the 5-HT1A receptor, ATP, and purinoceptors. It is hypothesized that serotonin facilitates gustatory signals by regulating the release of ATP through ATP-release channels possibly through phosphatidylinositol 4,5-bisphosphate resynthesis. By doing so, 5-HT1A activation prevents desensitization of post-synaptic purinergic receptors expressed on afferent nerve fibers and enhances the afferent signal. Serotonin may thus play a major modulatory role within peripheral taste in shaping the afferent taste signals prior to their transmission across gustatory nerves. PMID:25386961

How the workload impacts on cognitive cooperation: A pilot study.

PubMed

Sciaraffa, Nicolina; Borghini, Gianluca; Arico, Pietro; Di Flumeri, Gianluca; Toppi, Jlenia; Colosimo, Alfredo; Bezerianos, Anastatios; Thakor, Nitish V; Babiloni, Fabio

2017-07-01

Cooperation degradation can be seen as one of the main causes of human errors. Poor cooperation could arise from aberrant mental processes, such as mental overload, that negatively affect the user's performance. Using different levels of difficulty in a cooperative task, we combined behavioural, subjective and neurophysiological data with the aim to i) quantify the mental workload under which the crew was operating, ii) evaluate the degree of their cooperation, and iii) assess the impact of the workload demands on the cooperation levels. The combination of such data showed that high workload demand impacted significantly on the performance, workload perception, and degree of cooperation.

A Neural Theory of Visual Attention: Bridging Cognition and Neurophysiology

ERIC Educational Resources Information Center

Bundesen, Claus; Habekost, Thomas; Kyllingsbaek, Soren

2005-01-01

A neural theory of visual attention (NTVA) is presented. NTVA is a neural interpretation of C. Bundesen's (1990) theory of visual attention (TVA). In NTVA, visual processing capacity is distributed across stimuli by dynamic remapping of receptive fields of cortical cells such that more processing resources (cells) are devoted to behaviorally…

Edge Detection and Geometric Methods in Computer Vision,

DTIC Science & Technology

1985-02-01

enlightening discussion) Derivations or Eqs. 3.29, 3.31, 3.32 (some statistics) Experimental results (pictures)-- not very informative, extensive or useful. lie... neurophysiology and hardware design. If one views 9 the state space as a free vector space on the labels over the field of weights (which we take to be R), then

Hospital Information Systems for Clinical and Research Applications: A Survey of the Issues

DTIC Science & Technology

1983-06-01

potentials for auditory and visual nervous system activity) is being used intensively in the field of neurophysiology (27, 108, 109). In addition, the high...user group: this provides a community of enlightened users who can share ideas and experiences. (NOTE: NCHSR support ended January 1, 1983.) .Masor

Beyond the Bolus: Transgenic Tools for Investigating the Neurophysiology of Learning and Memory

ERIC Educational Resources Information Center

Lykken, Christine; Kentros, Clifford G.

2014-01-01

Understanding the neural mechanisms underlying learning and memory in the entorhinal-hippocampal circuit is a central challenge of systems neuroscience. For more than 40 years, electrophysiological recordings in awake, behaving animals have been used to relate the receptive fields of neurons in this circuit to learning and memory. However, the…

"Learning" and "Acquisition" -- How Real Is the Dichotomy: Some Neurophysical Evidence.

ERIC Educational Resources Information Center

Lueers, Nancy M.

The dichotomy of language acquisition versus language learning is critically examined by comparing the concepts presented in Krashen's Monitor Model and Stevick's Levertov Machine to information from the field of neurophysiology regarding the brain's processes. It is proposed that support exists for the theory that two very different processes…

"Machine" consciousness and "artificial" thought: an operational architectonics model guided approach.

PubMed

Fingelkurts, Andrew A; Fingelkurts, Alexander A; Neves, Carlos F H

2012-01-05

Instead of using low-level neurophysiology mimicking and exploratory programming methods commonly used in the machine consciousness field, the hierarchical operational architectonics (OA) framework of brain and mind functioning proposes an alternative conceptual-theoretical framework as a new direction in the area of model-driven machine (robot) consciousness engineering. The unified brain-mind theoretical OA model explicitly captures (though in an informal way) the basic essence of brain functional architecture, which indeed constitutes a theory of consciousness. The OA describes the neurophysiological basis of the phenomenal level of brain organization. In this context the problem of producing man-made "machine" consciousness and "artificial" thought is a matter of duplicating all levels of the operational architectonics hierarchy (with its inherent rules and mechanisms) found in the brain electromagnetic field. We hope that the conceptual-theoretical framework described in this paper will stimulate the interest of mathematicians and/or computer scientists to abstract and formalize principles of hierarchy of brain operations which are the building blocks for phenomenal consciousness and thought. Copyright © 2010 Elsevier B.V. All rights reserved.

Perisaccadic Updating of Visual Representations and Attentional States: Linking Behavior and Neurophysiology

PubMed Central

Marino, Alexandria C.; Mazer, James A.

2016-01-01

During natural vision, saccadic eye movements lead to frequent retinal image changes that result in different neuronal subpopulations representing the same visual feature across fixations. Despite these potentially disruptive changes to the neural representation, our visual percept is remarkably stable. Visual receptive field remapping, characterized as an anticipatory shift in the position of a neuron’s spatial receptive field immediately before saccades, has been proposed as one possible neural substrate for visual stability. Many of the specific properties of remapping, e.g., the exact direction of remapping relative to the saccade vector and the precise mechanisms by which remapping could instantiate stability, remain a matter of debate. Recent studies have also shown that visual attention, like perception itself, can be sustained across saccades, suggesting that the attentional control system can also compensate for eye movements. Classical remapping could have an attentional component, or there could be a distinct attentional analog of visual remapping. At this time we do not yet fully understand how the stability of attentional representations relates to perisaccadic receptive field shifts. In this review, we develop a vocabulary for discussing perisaccadic shifts in receptive field location and perisaccadic shifts of attentional focus, review and synthesize behavioral and neurophysiological studies of perisaccadic perception and perisaccadic attention, and identify open questions that remain to be experimentally addressed. PMID:26903820

Decrease of motor cortex excitability following exposure to a 20 Hz magnetic field as generated by a rotating permanent magnet.

PubMed

Gallasch, Eugen; Rafolt, Dietmar; Postruznik, Magdalena; Fresnoza, Shane; Christova, Monica

2018-04-19

Rotation of a static magnet over the motor cortex (MC) generates a transcranial alternating magnetic field (tAMF), and a linked alternating electrical field. The aim of this transcranial magnetic stimulation (TMS) study is to investigate whether such fields are able to influence MC excitability, and whether there are parallels to tACS induced effects. Fourteen healthy volunteers received 20 Hz tAMF stimulation over the MC, over the vertex, and 20 Hz tACS over the MC, each with a duration of 15 min. TMS assessments were performed before and after the interventions. Changes in motor evoked potentials (MEP), short interval intra-cortical inhibition (SICI) and intra-cortical facilitation (ICF) were evaluated. The tACS and the tAMF stimulation over the MC affected cortical excitability in a different way. After tAMF stimulation MEP amplitudes and ICF decreased and the effect of SICI increased. After tACS MEP amplitudes increased and there were no effects on SICI and ICF. The recorded single and paired pulse MEPs indicate a general decrease of MC excitability following 15 min of tAMF stimulation. The effects demonstrate that devices based on rotating magnets are potentially suited to become a novel brain stimulation tool in clinical neurophysiology. Copyright © 2018 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Group III/IV locomotor muscle afferents alter motor cortical and corticospinal excitability and promote central fatigue during cycling exercise.

PubMed

Sidhu, Simranjit K; Weavil, Joshua C; Mangum, Tyler S; Jessop, Jacob E; Richardson, Russell S; Morgan, David E; Amann, Markus

2017-01-01

To investigate the influence of group III/IV muscle afferents on the development of central fatigue and corticospinal excitability during exercise. Fourteen males performed cycling-exercise both under control-conditions (CTRL) and with lumbar intrathecal fentanyl (FENT) impairing feedback from leg muscle afferents. Transcranial magnetic- and cervicomedullary stimulation was used to monitor cortical versus spinal excitability. While fentanyl-blockade during non-fatiguing cycling had no effect on motor-evoked potentials (MEPs), cervicomedullary-evoked motor potentials (CMEPs) were 13±3% higher (P<0.05), resulting in a decrease in MEP/CMEP (P<0.05). Although the pre- to post-exercise reduction in resting twitch was greater in FENT vs. CTRL (-53±3% vs. -39±3%; P<0.01), the reduction in voluntary muscle activation was smaller (-2±2% vs. -10±2%; P<0.05). Compared to the start of fatiguing exercise, MEPs and CMEPs were unchanged at exhaustion in CTRL. In contrast, MEPs and MEP/CMEP increased 13±3% and 25±6% in FENT (P<0.05). During non-fatiguing exercise, group III/IV muscle afferents disfacilitate, or inhibit, spinal motoneurons and facilitate motor cortical cells. In contrast, during exhaustive exercise, group III/IV muscle afferents disfacilitate/inhibit the motor cortex and promote central fatigue. Group III/IV muscle afferents influence corticospinal excitability and central fatigue during whole-body exercise in humans. Copyright © 2016 International Federation of Clinical Neurophysiology. All rights reserved.

[Mental Imagery: Neurophysiology and Implications in Psychiatry].

PubMed

Martínez, Nathalie Tamayo

2014-03-01

To provide an explanation about what mental imagery is and some implications in psychiatry. This article is a narrative literature review. There are many terms in which imagery representations are described in different fields of research. They are defined as perceptions in the absence of an external stimulus, and can be created in any sensory modality. Their neurophysiological substrate is almost the same as the one activated during sensory perception. There is no unified theory about its function, but it is possibly the way that our brain uses and manipulates the information to respond to the environment. Mental imagery is an everyday phenomenon, and when it occurs in specific patterns it can be a sign of mental disorders. Copyright © 2014 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

Primate beta oscillations and rhythmic behaviors.

PubMed

Merchant, Hugo; Bartolo, Ramón

2018-03-01

The study of non-human primates in complex behaviors such as rhythm perception and entrainment is critical to understand the neurophysiological basis of human cognition. Next to reviewing the role of beta oscillations in human beat perception, here we discuss the role of primate putaminal oscillatory activity in the control of rhythmic movements that are guided by a sensory metronome or internally gated. The analysis of the local field potentials of the behaving macaques showed that gamma-oscillations reflect local computations associated with stimulus processing of the metronome, whereas beta-activity involves the entrainment of large putaminal circuits, probably in conjunction with other elements of cortico-basal ganglia-thalamo-cortical circuit, during internally driven rhythmic tapping. Thus, this review emphasizes the need of parametric neurophysiological observations in non-human primates that display a well-controlled behavior during high-level cognitive processes.

Incorporating neurophysiological concepts in mathematical thermoregulation models

NASA Astrophysics Data System (ADS)

Kingma, Boris R. M.; Vosselman, M. J.; Frijns, A. J. H.; van Steenhoven, A. A.; van Marken Lichtenbelt, W. D.

2014-01-01

Skin blood flow (SBF) is a key player in human thermoregulation during mild thermal challenges. Various numerical models of SBF regulation exist. However, none explicitly incorporates the neurophysiology of thermal reception. This study tested a new SBF model that is in line with experimental data on thermal reception and the neurophysiological pathways involved in thermoregulatory SBF control. Additionally, a numerical thermoregulation model was used as a platform to test the function of the neurophysiological SBF model for skin temperature simulation. The prediction-error of the SBF-model was quantified by root-mean-squared-residual (RMSR) between simulations and experimental measurement data. Measurement data consisted of SBF (abdomen, forearm, hand), core and skin temperature recordings of young males during three transient thermal challenges (1 development and 2 validation). Additionally, ThermoSEM, a thermoregulation model, was used to simulate body temperatures using the new neurophysiological SBF-model. The RMSR between simulated and measured mean skin temperature was used to validate the model. The neurophysiological model predicted SBF with an accuracy of RMSR < 0.27. Tskin simulation results were within 0.37 °C of the measured mean skin temperature. This study shows that (1) thermal reception and neurophysiological pathways involved in thermoregulatory SBF control can be captured in a mathematical model, and (2) human thermoregulation models can be equipped with SBF control functions that are based on neurophysiology without loss of performance. The neurophysiological approach in modelling thermoregulation is favourable over engineering approaches because it is more in line with the underlying physiology.

Three-dimensional brain reconstruction of in vivo electrode tracks for neuroscience and neural prosthetic applications

PubMed Central

Markovitz, Craig D.; Tang, Tien T.; Edge, David P.; Lim, Hubert H.

2012-01-01

The brain is a densely interconnected network that relies on populations of neurons within and across multiple nuclei to code for features leading to perception and action. However, the neurophysiology field is still dominated by the characterization of individual neurons, rather than simultaneous recordings across multiple regions, without consistent spatial reconstruction of their locations for comparisons across studies. There are sophisticated histological and imaging techniques for performing brain reconstructions. However, what is needed is a method that is relatively easy and inexpensive to implement in a typical neurophysiology lab and provides consistent identification of electrode locations to make it widely used for pooling data across studies and research groups. This paper presents our initial development of such an approach for reconstructing electrode tracks and site locations within the guinea pig inferior colliculus (IC) to identify its functional organization for frequency coding relevant for a new auditory midbrain implant (AMI). Encouragingly, the spatial error associated with different individuals reconstructing electrode tracks for the same midbrain was less than 65 μm, corresponding to an error of ~1.5% relative to the entire IC structure (~4–5 mm diameter sphere). Furthermore, the reconstructed frequency laminae of the IC were consistently aligned across three sampled midbrains, demonstrating the ability to use our method to combine location data across animals. Hopefully, through further improvements in our reconstruction method, it can be used as a standard protocol across neurophysiology labs to characterize neural data not only within the IC but also within other brain regions to help bridge the gap between cellular activity and network function. Clinically, correlating function with location within and across multiple brain regions can guide optimal placement of electrodes for the growing field of neural prosthetics. PMID:22754502

The American Society of Neurophysiological Monitoring position statements project.

PubMed

Morledge, David E; Stecker, Mark

2006-02-01

The American Society of Neurophysiological Monitoring (ASNM) is developing position statements aimed at assisting practitioners and others in making decisions regarding neurophysiological monitoring practice. This paper describes the procedures used in drafting these documents.

A Multimodal, SU-8 - Platinum - Polyimide Microelectrode Array for Chronic In Vivo Neurophysiology

PubMed Central

Márton, Gergely; Orbán, Gábor; Kiss, Marcell; Fiáth, Richárd; Pongrácz, Anita; Ulbert, István

2015-01-01

Utilization of polymers as insulator and bulk materials of microelectrode arrays (MEAs) makes the realization of flexible, biocompatible sensors possible, which are suitable for various neurophysiological experiments such as in vivo detection of local field potential changes on the surface of the neocortex or unit activities within the brain tissue. In this paper the microfabrication of a novel, all-flexible, polymer-based MEA is presented. The device consists of a three dimensional sensor configuration with an implantable depth electrode array and brain surface electrodes, allowing the recording of electrocorticographic (ECoG) signals with laminar ones, simultaneously. In vivo recordings were performed in anesthetized rat brain to test the functionality of the device under both acute and chronic conditions. The ECoG electrodes recorded slow-wave thalamocortical oscillations, while the implanted component provided high quality depth recordings. The implants remained viable for detecting action potentials of individual neurons for at least 15 weeks. PMID:26683306

Fabrication of nanoelectrodes for neurophysiology: cathodic electrophoretic paint insulation and focused ion beam milling

PubMed Central

Qiao, Yi; Chen, Jie; Guo, Xiaoli; Cantrell, Donald; Ruoff, Rodney; Troy, John

2005-01-01

The fabrication and characterization of tungsten nanoelectrodes insulated with cathodic electrophoretic paint is described together with their application within the field of neurophysiology. The tip of a 127 μm diameter tungsten wire was etched down to less than 100 nm and then insulated with cathodic electrophoretic paint. Focused ion beam (FIB) polishing was employed to remove the insulation at the electrode’s apex, leaving a nanoscale sized conductive tip of 100–1000 nm. The nanoelectrodes were examined by scanning electron microscopy (SEM) and their electrochemical properties characterized by steady state linear sweep voltammetry. Electrode impedance at 1 kHz was measured too. The ability of a 700 nm tipped electrode to record well-isolated action potentials extracellularly from single visual neurons in vivo was demonstrated. Such electrodes have the potential to open new populations of neurons to study. PMID:16467926

A Multimodal, SU-8 - Platinum - Polyimide Microelectrode Array for Chronic In Vivo Neurophysiology.

PubMed

Márton, Gergely; Orbán, Gábor; Kiss, Marcell; Fiáth, Richárd; Pongrácz, Anita; Ulbert, István

2015-01-01

Utilization of polymers as insulator and bulk materials of microelectrode arrays (MEAs) makes the realization of flexible, biocompatible sensors possible, which are suitable for various neurophysiological experiments such as in vivo detection of local field potential changes on the surface of the neocortex or unit activities within the brain tissue. In this paper the microfabrication of a novel, all-flexible, polymer-based MEA is presented. The device consists of a three dimensional sensor configuration with an implantable depth electrode array and brain surface electrodes, allowing the recording of electrocorticographic (ECoG) signals with laminar ones, simultaneously. In vivo recordings were performed in anesthetized rat brain to test the functionality of the device under both acute and chronic conditions. The ECoG electrodes recorded slow-wave thalamocortical oscillations, while the implanted component provided high quality depth recordings. The implants remained viable for detecting action potentials of individual neurons for at least 15 weeks.

Evidence from Neurolinguistic Methodologies: Can It Actually Inform Linguistic/Language Acquisition Theories and Translate to Evidence-Based Applications?

ERIC Educational Resources Information Center

Roberts, Leah; González Alonso, Jorge; Pliatsikas, Christos; Rothman, Jason

2018-01-01

This special issue is a testament to the recent burgeoning interest by theoretical linguists, language acquisitionists and teaching practitioners in the neuroscience of language. It offers a highly valuable, state-of-the-art overview of the neurophysiological methods that are currently being applied to questions in the field of second language…

Electroreception in the ratfish (Hydrolagus colliei).

PubMed

Fields, R D; Lange, G D

1980-02-01

Behavioral and neurophysiological experiments and anatomical work indicate that the ampullar structures on the head of fish of the subclass Holocephali are sense organs responsive to weak electric fields and are functionally and structurally homologous to the ampullae of Lorenzini in elasmobranchs. It is concluded that, as in elasmobranchs, these organs are used to detect bioelectric and other natural electric phenomena in the environment.

Neurophysiological Indices of the Effect of Cognates on Vowel Perception in Late Spanish-English Bilinguals

ERIC Educational Resources Information Center

Tessel, Carol A.

2013-01-01

The field of research in bilingualism and second language (L2) acquisition has yielded overwhelming evidence that acquiring a second language later in life will result in less accurate production and perception of consonants and vowels in the second language. These effects, in part, are a result of interference from the already formed phonetic…

Driving working memory with frequency-tuned noninvasive brain stimulation.

PubMed

Albouy, Philippe; Baillet, Sylvain; Zatorre, Robert J

2018-04-29

Frequency-tuned noninvasive brain stimulation is a recent approach in cognitive neuroscience that involves matching the frequency of transcranially applied electromagnetic fields to that of specific oscillatory components of the underlying neurophysiology. The objective of this method is to modulate ongoing/intrinsic brain oscillations, which correspond to rhythmic fluctuations of neural excitability, to causally change behavior. We review the impact of frequency-tuned noninvasive brain stimulation on the research field of human working memory. We argue that this is a powerful method to probe and understand the mechanisms of memory functions, targeting specifically task-related oscillatory dynamics, neuronal representations, and brain networks. We report the main behavioral and neurophysiological outcomes published to date, in particular, how functionally relevant oscillatory signatures in signal power and interregional connectivity yield causal changes of working memory abilities. We also present recent developments of the technique that aim to modulate cross-frequency coupling in polyrhythmic neural activity. Overall, the method has led to significant advances in our understanding of the mechanisms of systems neuroscience, and the role of brain oscillations in cognition and behavior. We also emphasize the translational impact of noninvasive brain stimulation techniques in the development of therapeutic approaches. © 2018 New York Academy of Sciences.

Neurophysiological tools to investigate consumer's gender differences during the observation of TV commercials.

PubMed

Vecchiato, Giovanni; Maglione, Anton Giulio; Cherubino, Patrizia; Wasikowska, Barbara; Wawrzyniak, Agata; Latuszynska, Anna; Latuszynska, Malgorzata; Nermend, Kesra; Graziani, Ilenia; Leucci, Maria Rita; Trettel, Arianna; Babiloni, Fabio

2014-01-01

Neuromarketing is a multidisciplinary field of research whose aim is to investigate the consumers' reaction to advertisements from a neuroscientific perspective. In particular, the neuroscience field is thought to be able to reveal information about consumer preferences which are unobtainable through conventional methods, including submitting questionnaires to large samples of consumers or performing psychological personal or group interviews. In this scenario, we performed an experiment in order to investigate cognitive and emotional changes of cerebral activity evaluated by neurophysiologic indices during the observation of TV commercials. In particular, we recorded the electroencephalographic (EEG), galvanic skin response (GSR), and heart rate (HR) in a group of 28 healthy subjects during the observation of a series of TV advertisements that have been grouped by commercial categories. Comparisons of cerebral indices have been performed to highlight gender differences between commercial categories and scenes of interest of two specific commercials. Findings show how EEG methodologies, along with the measurements of autonomic variables, could be used to obtain hidden information to marketers not obtainable otherwise. Most importantly, it was suggested how these tools could help to analyse the perception of TV advertisements and differentiate their production according to the consumer's gender.

Neurophysiological Tools to Investigate Consumer's Gender Differences during the Observation of TV Commercials

PubMed Central

Maglione, Anton Giulio; Wasikowska, Barbara; Wawrzyniak, Agata; Graziani, Ilenia; Trettel, Arianna

2014-01-01

Neuromarketing is a multidisciplinary field of research whose aim is to investigate the consumers' reaction to advertisements from a neuroscientific perspective. In particular, the neuroscience field is thought to be able to reveal information about consumer preferences which are unobtainable through conventional methods, including submitting questionnaires to large samples of consumers or performing psychological personal or group interviews. In this scenario, we performed an experiment in order to investigate cognitive and emotional changes of cerebral activity evaluated by neurophysiologic indices during the observation of TV commercials. In particular, we recorded the electroencephalographic (EEG), galvanic skin response (GSR), and heart rate (HR) in a group of 28 healthy subjects during the observation of a series of TV advertisements that have been grouped by commercial categories. Comparisons of cerebral indices have been performed to highlight gender differences between commercial categories and scenes of interest of two specific commercials. Findings show how EEG methodologies, along with the measurements of autonomic variables, could be used to obtain hidden information to marketers not obtainable otherwise. Most importantly, it was suggested how these tools could help to analyse the perception of TV advertisements and differentiate their production according to the consumer's gender. PMID:25147579

The Role of 3T Magnetic Resonance Imaging for Targeting the Human Subthalamic Nucleus in Deep Brain Stimulation for Parkinson Disease.

PubMed

Longhi, Michele; Ricciardi, Giuseppe; Tommasi, Giorgio; Nicolato, Antonio; Foroni, Roberto; Bertolasi, Laura; Beltramello, Alberto; Moretto, Giuseppe; Tinazzi, Michele; Gerosa, Massimo

2015-05-01

Chronic stimulation of the human subthalamic nucleus (STN) is gradually becoming accepted as a long-term therapeutic option for patients with advanced Parkinson disease (PD). 3Tesla (T) magnetic resonance imaging (MRI) improves contrast resolution in basal ganglia nuclei containing high levels of iron, because of magnetic susceptibility effects that increase significantly as the magnetic field gets higher. This phenomenon can be used for better visualization of the STN and may reduce the time necessary for detailed microrecording (MER) mapping, increasing surgery efficacy and lowering morbidity. The objective of this retrospective study is to analyze a population of 20 deep brain stimulation (DBS) electrode implanted patients with PD divided into two groups in which different targeting methods were used. Mean age was 56 years (range 37 to 69 years). Mean disease duration was 11.6 years. Mean follow-up was 12 months (range 6 to 36 months). Patients were divided into two groups: Group A contained 6 patients who underwent STN targeting using 1T stereotactic (T1w + T2w) MRI plus STN indirect atlas derived targeting. Group B consisted of 14 patients who underwent STN targeting using 3T nonstereotactic (T2w) MRI fused with 1T T1w stereotactic MRI and STN direct targeting. For statistical analysis, we compared (five different parameters in both (matched) groups: Unified Parkinson's disease rating scale (UPDRS) score reduction (medication off before surgery against stimulation on/medication off after surgery), postoperative drug reduction, duration of surgery, the "central preoperative track" chosen as final implantation track during surgery, and correspondence between the targeted STN and the intraoperative neurophysiologic data. Mean UPDRS III score reduction (medication off/stimulation on versus preoperative medication off) was 69% in Group A and 74% in Group B (p = 0.015, log-rank test) respectively. Postoperatively, antiparkinsonian treatment was reduced by 66% in Group A and 75% in Group B (p = 0.006, log-rank test). The preoperative "central" track (which corresponds to ideal STN targeting) proved to be the most clinically effective in 2/12 leads for Group A versus 21/28 for Group B (p < 0.001).Neurophysiologic data confirmed these results; the hypothetical target was confirmed by MER data in 76% of tracks in Group A, and in 75% of tracks in Group B (p < 0.001, univariate and multivariate analysis). 3T MRI appears to be a useful tool in STN-DBS preoperative targeting. Neurophysiologic testing remains fundamental to determine lead deepness (and prevent clinical side effects. Georg Thieme Verlag KG Stuttgart · New York.

Usefulness of intraoperative electromyographic monitoring of oculomotor and abducens nerves during skull base surgery.

PubMed

Li, Zi-Yi; Li, Ming-Chu; Liang, Jian-Tao; Bao, Yu-Hai; Chen, Ge; Guo, Hong-Chuan; Ling, Feng

2017-10-01

Intraoperative neurophysiologic monitoring of the extraocular cranial nerve (EOCN) is not commonly performed because of technical difficulty and risk, reliability of the result and predictability of the postoperative function of the EOCN. We performed oculomotor nerve (CN III) and abducens nerve (CN VI) intraoperative monitoring in patients with skull base surgery by recording the spontaneous muscle activity (SMA) and compound muscle action potential (CMAP). Two types of needle electrodes of different length were percutaneously inserted into the extraocular muscles with the free-hand technique. We studied the relationships between the SMA and CMAP and postoperative function of CN III and CN VI. A total of 23 patients were included. Nineteen oculomotor nerves and 22 abducens nerves were monitored during surgery, respectively. Neurotonic discharge had a positive predictive value of less than 50% and negative predictive value of more than 80% for postoperative CN III and CN VI dysfunction. The latency of patients with postoperative CN III dysfunction was 2.79 ± 0.13 ms, longer than that with intact CN III function (1.73 ± 0.11 ms). One patient had transient CN VI dysfunction, whose CMAP latency (2.54 ms) was longer than that of intact CN VI function (2.11 ± 0.38 ms). There was no statistically significant difference between patients with paresis and with intact function. The method of intraoperative monitoring of EOCNs described here is safe and useful to record responses of SMA and CMAP. Neurotonic discharge seems to have limited value in predicting the postoperative function of CN III and CN VI. The onset latency of CMAP longer than 2.5 ms after tumor removal is probably relevant to postoperative CN III and CN VI dysfunction. However, a definite quantitative relationship has not been found between the amplitude and stimulation intensity of CMAP and the postoperative outcome of CN III and CN VI.

Functional Neuroanatomy and Neurophysiology of Functional Neurological Disorders (Conversion Disorder).

PubMed

Voon, Valerie; Cavanna, Andrea E; Coburn, Kerry; Sampson, Shirlene; Reeve, Alya; LaFrance, W Curt

2016-01-01

Much is known regarding the physical characteristics, comorbid symptoms, psychological makeup, and neuropsychological performance of patients with functional neurological disorders (FNDs)/conversion disorders. Gross neurostructural deficits do not account for the patients' deficits or symptoms. This review describes the literature focusing on potential neurobiological (i.e. functional neuroanatomic/neurophysiological) findings among individuals with FND, examining neuroimaging and neurophysiological studies of patients with the various forms of motor and sensory FND. In summary, neural networks and neurophysiologic mechanisms may mediate "functional" symptoms, reflecting neurobiological and intrapsychic processes.

Clinical outcome and intraoperative neurophysiology for focal limb dystonic tremor without generalized dystonia treated with deep brain stimulation.

PubMed

Ramirez-Zamora, Adolfo; Kaszuba, Brian; Gee, Lucy; Prusik, Julia; Molho, Eric; Wilock, Meghan; Shin, Damian; Pilitsis, Julie G

2016-11-01

Dystonic tremor (DT) is defined as a postural/kinetic tremor occurring in the body region affected by dystonia. DT is typically characterized by focal tremors with irregular amplitudes and variable frequencies typically below 7Hz. Pharmacological treatment is generally unsuccessful and guidelines for deep brain stimulation (DBS) targeting and indications are scarce. In this article, we present the outcome and neurophysiologic data of two patients with refractory, focal limb DT treated with Globus Pallidus interna (Gpi) DBS and critically review the current literature regarding surgical treatment of DT discussing stereotactic targets and treatment considerations. A search of literature concerning treatment of DT was conducted. Additionally, Gpi DBS was performed in two patients with DT and microelectrode recordings for multi unit analysis (MUAs) and local field potentials (LFPs) were obtained. The mean percentage improvement in tremor severity was 80.5% at 3 years follow up. MUAs and LFPs did not show significant differences in DT patients compared with other forms of dystonia or PD except for higher interspikes bursting indices. LFP recordings in DT demonstrated high power at low frequencies with action (<3.5Hz). Gpi DBS is an effective treatment in patients with focal limb DT without associated generalized dystonia. Intraoperative neurophysiologic findings suggest that DT is part of phenotypic motor manifestations in dystonia. Copyright © 2016 Elsevier B.V. All rights reserved.

Recent developments in the remote radio control of insect flight.

PubMed

Sato, Hirotaka; Maharbiz, Michel M

2010-01-01

The continuing miniaturization of digital circuits and the development of low power radio systems coupled with continuing studies into the neurophysiology and dynamics of insect flight are enabling a new class of implantable interfaces capable of controlling insects in free flight for extended periods. We provide context for these developments, review the state-of-the-art and discuss future directions in this field.

[Ideal subspecialty training in the field of neurology - competence required for the experts: neurophysiology].

PubMed

Kohara, Nobuo

2012-01-01

All neurologists have to make a differential diagnosis of consciousness loss by EEG. The judgment of epilepsy is especially important. Experts of neurology were also required to determine the level and etiology of the acute or chronic weakness or numbness by EMG with nerve conduction study. Hands on seminar and e-learning would be useful to acquire these tools.

Recent Developments in the Remote Radio Control of Insect Flight

PubMed Central

Sato, Hirotaka; Maharbiz, Michel M.

2010-01-01

The continuing miniaturization of digital circuits and the development of low power radio systems coupled with continuing studies into the neurophysiology and dynamics of insect flight are enabling a new class of implantable interfaces capable of controlling insects in free flight for extended periods. We provide context for these developments, review the state-of-the-art and discuss future directions in this field. PMID:21629761

Research Directions in Remote Detection of Covert Tactical Adversarial Intent of Individuals in Asymmetric Operations

DTIC Science & Technology

2010-07-01

To be successful, the research needs to integrate kinesiological , neurophysiological, psychological, and cognitive science, and sociocultural... kinesiological neurophysiological, psychological, and cognitive science and sociocultural anthropology and information science components. Research and...successful, the research needs to integrate kinesiological , neurophysiological, psychological, and cognitive science, and sociocultural

Resting-State Neurophysiological Activity Patterns in Young People with ASD, ADHD, and ASD + ADHD

ERIC Educational Resources Information Center

Shephard, Elizabeth; Tye, Charlotte; Ashwood, Karen L.; Azadi, Bahar; Asherson, Philip; Bolton, Patrick F.; McLoughlin, Grainne

2018-01-01

Altered power of resting-state neurophysiological activity has been associated with autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD), which commonly co-occur. We compared resting-state neurophysiological power in children with ASD, ADHD, co-occurring ASD + ADHD, and typically developing controls. Children with ASD…

Neurophysiological intraoperative monitoring during an optic nerve schwannoma removal.

PubMed

San-Juan, Daniel; Escanio Cortés, Manuel; Tena-Suck, Martha; Orozco Garduño, Adolfo Josué; López Pizano, Jesús Alejandro; Villanueva Domínguez, Jonathan; Fernández Gónzalez-Aragón, Maricarmen; Gómez-Amador, Juan Luis

2017-10-01

This paper reports the case of a patient with optic nerve schwannoma and the first use of neurophysiological intraoperative monitoring of visual evoked potentials during the removal of such tumor with no postoperative visual damage. Schwannomas are benign neoplasms of the peripheral nervous system arising from the neural crest-derived Schwann cells, these tumors are rarely located in the optic nerve and the treatment consists on surgical removal leading to high risk of damage to the visual pathway. Case report of a thirty-year-old woman with an optic nerve schwannoma. The patient underwent surgery for tumor removal on the left optic nerve through a left orbitozygomatic approach with intraoperative monitoring of left II and III cranial nerves. We used Nicolet Endeavour CR IOM (Carefusion, Middleton WI, USA) to performed visual evoked potentials stimulating binocularly with LED flash goggles with the patient´s eyes closed and direct epidural optic nerve stimulation delivering rostral to the tumor a rectangular current pulse. At follow up examinations 7 months later, the left eye visual acuity was 20/60; Ishihara score was 8/8 in both eyes; the right eye photomotor reflex was normal and left eye was mydriatic and arreflectic; optokinetic reflex and ocular conjugate movements were normal. In this case, the epidural direct electrical stimulation of optic nerve provided stable waveforms during optic nerve schwannoma resection without visual loss.

Clinical and neurophysiological investigation of a large family with dominant Charcot-Marie-Tooth type 2 disease with pyramidal signs.

PubMed

Neves, Eduardo Luis de Aquino; Kok, Fernando

2011-06-01

Charcot-Marie-Tooth (CMT) disease is a hereditary neuropathy of motor and sensory impairment with distal predominance. Atrophy and weakness of lower limbs are the first signs of the disease. It can be classified, with the aid of electromyography and nerve conduction studies, as demyelinating (CMT1) or axonal (CMT2). Clinical and neurophysiological investigation of a large multigenerational family with CMT2 with autosomal dominant mode of transmission. Fifty individuals were evaluated and neurophysiological studies performed in 22 patients. Thirty individuals had clinical signs of motor-sensory neuropathy. Babinski sign was present in 14 individuals. Neurophysiological study showed motor-sensory axonal polyneuropathy. The clinical and neurophysiological characteristics of this family does not differ from those observed with other forms of CMT, except for the high prevalence of Babinski sign.

Descartes' visit to the town library, or how Augustinian is Descartes' neurophysiology?

PubMed

Smith, C U

1998-08-01

Rene Descartes was early accused of taking his central philosophical proposition from St Augustine. Did he also take his central neurophysiological concept from the same source? This is the question which this paper sets out to answer. It is concluded that the foundational neurophysiology propounded in L'Homme does indeed show strong and interesting resemblences to Augustine's largely Erasistratean version. Descartes, however, working within the new paradigm of seventeenth-century physical science, introduced a new principle: whereas Augustine's neurophysiology is pervaded throughout by a vital factor, the pneuma, Descartes' theory involved only inanimate material forces. It is concluded, further, that in spite of the interesting similarities between Augustinian and Cartesian neurophysiology there is no evidence for any direct plagiarism. It seems more likely that Augustine's influence was filtered through the Galenical physiologists of Descartes' own time and of the preceding century.

Early event related fields during visually evoked pain anticipation.

PubMed

Gopalakrishnan, Raghavan; Burgess, Richard C; Plow, Ela B; Floden, Darlene P; Machado, Andre G

2016-03-01

Pain experience is not only a function of somatosensory inputs. Rather, it is strongly influenced by cognitive and affective pathways. Pain anticipatory phenomena, an important limitation to rehabilitative efforts in the chronic state, are processed by associative and limbic networks, along with primary sensory cortices. Characterization of neurophysiological correlates of pain anticipation, particularly during very early stages of neural processing is critical for development of therapeutic interventions. Here, we utilized magnetoencephalography to study early event-related fields (ERFs) in healthy subjects exposed to a 3 s visual countdown task that preceded a painful stimulus, a non-painful stimulus or no stimulus. We found that the first countdown cue, but not the last cue, evoked critical ERFs signaling anticipation, attention and alertness to the noxious stimuli. Further, we found that P2 and N2 components were significantly different in response to first-cues that signaled incoming painful stimuli when compared to non-painful or no stimuli. The findings indicate that early ERFs are relevant neural substrates of pain anticipatory phenomena and could be potentially serve as biomarkers. These measures could assist in the development of neurostimulation approaches aimed at curbing the negative effects of pain anticipation during rehabilitation. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

The relationship between knowledge of pain neurophysiology and fear avoidance in people with chronic pain: A point in time, observational study.

PubMed

Fletcher, Claire; Bradnam, Lynley; Barr, Christopher

2016-05-01

Chronic pain is prevalent in the western world; however fear of pain often has a greater impact than the degree of initial injury. The aim of this study was to explore the relationship between knowledge of the neurophysiology of pain and fear avoidance in individuals diagnosed with chronic pain. Twenty-nine people with chronic musculoskeletal pain were recruited and completed questionnaires to determine their understanding of pain neurophysiology and the degree of their fear avoidance beliefs. There was an inverse relationship between knowledge of pain neurophysiology and the level of fear avoidance. Patients with higher pain knowledge reported less fear avoidance and lower perceived disability due to pain. There was no relationship with the educational level or compensable status for either variable. The findings suggest that fear avoidance is positively influenced by neurophysiology of pain education, so that a higher level of pain knowledge is associated with less activity-related fear. The clinical implication is that reducing fear avoidance/kinesiophobia using neurophysiology of pain education in people with chronic pain may provide an effective strategy to help manage fear avoidance and related disability in the chronic pain population in order to improve treatment outcomes.

How challenges in auditory fMRI led to general advancements for the field.

PubMed

Talavage, Thomas M; Hall, Deborah A

2012-08-15

In the early years of fMRI research, the auditory neuroscience community sought to expand its knowledge of the underlying physiology of hearing, while also seeking to come to grips with the inherent acoustic disadvantages of working in the fMRI environment. Early collaborative efforts between prominent auditory research laboratories and prominent fMRI centers led to development of a number of key technical advances that have subsequently been widely used to elucidate principles of auditory neurophysiology. Perhaps the key imaging advance was the simultaneous and parallel development of strategies to use pulse sequences in which the volume acquisitions were "clustered," providing gaps in which stimuli could be presented without direct masking. Such sequences have become widespread in fMRI studies using auditory stimuli and also in a range of translational research domains. This review presents the parallel stories of the people and the auditory neurophysiology research that led to these sequences. Copyright © 2011 Elsevier Inc. All rights reserved.

Neuro-Physiological Psychotherapy (NPP): The development and application of an integrative, wrap-around service and treatment programme for maltreated children placed in adoptive and foster care placements.

PubMed

Vaughan, Jay; McCullough, Elaine; Burnell, Alan

2016-10-01

This article describes the development and application of a wrap-around, multidisciplinary, brain-based, developmental and attachment-focussed intervention for children who have experienced significant trauma in the context of their early life. It outlines the presentation of the children and families who are referred to the service and the model of treatment that they receive. In doing so, it identifies the core components underpinning Neuro-Physiological Psychotherapy (NPP) and links the application of the integrative model to research and practice in the field of neuroscience and attachment and to the use of therapeutic approaches that are beneficial to maltreated children and their adoptive parents. It highlights the need for a neuro-sequential approach that impacts all aspects of the child's life in the effort to redress the impact of developmental trauma with the aim of improving their overall functioning and their ability to develop healthy relationships into the future. © The Author(s) 2016.

Thorough specification of the neurophysiologic processes underlying behavior and of their manifestation in EEG - demonstration with the go/no-go task.

PubMed

Shahaf, Goded; Pratt, Hillel

2013-01-01

In this work we demonstrate the principles of a systematic modeling approach of the neurophysiologic processes underlying a behavioral function. The modeling is based upon a flexible simulation tool, which enables parametric specification of the underlying neurophysiologic characteristics. While the impact of selecting specific parameters is of interest, in this work we focus on the insights, which emerge from rather accepted assumptions regarding neuronal representation. We show that harnessing of even such simple assumptions enables the derivation of significant insights regarding the nature of the neurophysiologic processes underlying behavior. We demonstrate our approach in some detail by modeling the behavioral go/no-go task. We further demonstrate the practical significance of this simplified modeling approach in interpreting experimental data - the manifestation of these processes in the EEG and ERP literature of normal and abnormal (ADHD) function, as well as with comprehensive relevant ERP data analysis. In-fact we show that from the model-based spatiotemporal segregation of the processes, it is possible to derive simple and yet effective and theory-based EEG markers differentiating normal and ADHD subjects. We summarize by claiming that the neurophysiologic processes modeled for the go/no-go task are part of a limited set of neurophysiologic processes which underlie, in a variety of combinations, any behavioral function with measurable operational definition. Such neurophysiologic processes could be sampled directly from EEG on the basis of model-based spatiotemporal segregation.

A portable platform to collect and review behavioral data simultaneously with neurophysiological signals.

PubMed

Tianxiao Jiang; Siddiqui, Hasan; Ray, Shruti; Asman, Priscella; Ozturk, Musa; Ince, Nuri F

2017-07-01

This paper presents a portable platform to collect and review behavioral data simultaneously with neurophysiological signals. The whole system is comprised of four parts: a sensor data acquisition interface, a socket server for real-time data streaming, a Simulink system for real-time processing and an offline data review and analysis toolbox. A low-cost microcontroller is used to acquire data from external sensors such as accelerometer and hand dynamometer. The micro-controller transfers the data either directly through USB or wirelessly through a bluetooth module to a data server written in C++ for MS Windows OS. The data server also interfaces with the digital glove and captures HD video from webcam. The acquired sensor data are streamed under User Datagram Protocol (UDP) to other applications such as Simulink/Matlab for real-time analysis and recording. Neurophysiological signals such as electroencephalography (EEG), electrocorticography (ECoG) and local field potential (LFP) recordings can be collected simultaneously in Simulink and fused with behavioral data. In addition, we developed a customized Matlab Graphical User Interface (GUI) software to review, annotate and analyze the data offline. The software provides a fast, user-friendly data visualization environment with synchronized video playback feature. The software is also capable of reviewing long-term neural recordings. Other featured functions such as fast preprocessing with multithreaded filters, annotation, montage selection, power-spectral density (PSD) estimate, time-frequency map and spatial spectral map are also implemented.

Functional Specialization in the Lower and Upper Visual Fields in Humans: Its Ecological Origins and Neurophysiological Implications

DTIC Science & Technology

1990-01-01

in that the with this hypothesis are the many reports (e.g., Adler - crossed-disparity system does appear to develop first Grinberg & Stark 1978... Rodman et al. 1986) that survives as independent of hemispheric asymmetries and additive to striate lesions critically depends on the superior...Perfomance. IRAAI human brain. No longer can visual cortical physiology Adler -Grinberg, D. & Stark, L. (1978) Eye movements, scanpaths, and dyslexia

Assessing mNIS+7Ionis and international neurologists' proficiency in a familial amyloidotic polyneuropathy trial.

PubMed

Dyck, Peter J; Kincaid, John C; Dyck, P James B; Chaudhry, Vinay; Goyal, Namita A; Alves, Christina; Salhi, Hayet; Wiesman, Janice F; Labeyrie, Celine; Robinson-Papp, Jessica; Cardoso, Márcio; Laura, Matilde; Ruzhansky, Katherine; Cortese, Andrea; Brannagan, Thomas H; Khoury, Julie; Khella, Sami; Waddington-Cruz, Márcia; Ferreira, João; Wang, Annabel K; Pinto, Marcus V; Ayache, Samar S; Benson, Merrill D; Berk, John L; Coelho, Teresa; Polydefkis, Michael; Gorevic, Peter; Adams, David H; Plante-Bordeneuve, Violaine; Whelan, Carol; Merlini, Giampaolo; Heitner, Stephen; Drachman, Brian M; Conceição, Isabel; Klein, Christopher J; Gertz, Morie A; Ackermann, Elizabeth J; Hughes, Steven G; Mauermann, Michelle L; Bergemann, Rito; Lodermeier, Karen A; Davies, Jenny L; Carter, Rickey E; Litchy, William J

2017-11-01

Polyneuropathy signs (Neuropathy Impairment Score, NIS), neurophysiologic tests (m+7 Ionis ), disability, and health scores were assessed in baseline evaluations of 100 patients entered into an oligonucleotide familial amyloidotic polyneuropathy (FAP) trial. We assessed: (1) Proficiency of grading neurologic signs and correlation with neurophysiologic tests, and (2) clinometric performance of modified NIS+7 neurophysiologic tests (mNIS+7 Ionis ) and its subscores and correlation with disability and health scores. The mNIS+7 Ionis sensitively detected, characterized, and broadly scaled diverse polyneuropathy impairments. Polyneuropathy signs (NIS and subscores) correlated with neurophysiology tests, disability, and health scores. Smart Somatotopic Quantitative Sensation Testing of heat as pain 5 provided a needed measure of small fiber involvement not adequately assessed by other tests. Specially trained neurologists accurately assessed neuropathy signs as compared to referenced neurophysiologic tests. The score, mNIS+7 Ionis , broadly detected, characterized, and scaled polyneuropathy abnormality in FAP, which correlated with disability and health scores. Muscle Nerve 56: 901-911, 2017. © 2017 Wiley Periodicals, Inc.

Neurophysiological Influence of Musical Training on Speech Perception

PubMed Central

Shahin, Antoine J.

2011-01-01

Does musical training affect our perception of speech? For example, does learning to play a musical instrument modify the neural circuitry for auditory processing in a way that improves one's ability to perceive speech more clearly in noisy environments? If so, can speech perception in individuals with hearing loss (HL), who struggle in noisy situations, benefit from musical training? While music and speech exhibit some specialization in neural processing, there is evidence suggesting that skills acquired through musical training for specific acoustical processes may transfer to, and thereby improve, speech perception. The neurophysiological mechanisms underlying the influence of musical training on speech processing and the extent of this influence remains a rich area to be explored. A prerequisite for such transfer is the facilitation of greater neurophysiological overlap between speech and music processing following musical training. This review first establishes a neurophysiological link between musical training and speech perception, and subsequently provides further hypotheses on the neurophysiological implications of musical training on speech perception in adverse acoustical environments and in individuals with HL. PMID:21716639

Neurophysiological influence of musical training on speech perception.

PubMed

Shahin, Antoine J

2011-01-01

Does musical training affect our perception of speech? For example, does learning to play a musical instrument modify the neural circuitry for auditory processing in a way that improves one's ability to perceive speech more clearly in noisy environments? If so, can speech perception in individuals with hearing loss (HL), who struggle in noisy situations, benefit from musical training? While music and speech exhibit some specialization in neural processing, there is evidence suggesting that skills acquired through musical training for specific acoustical processes may transfer to, and thereby improve, speech perception. The neurophysiological mechanisms underlying the influence of musical training on speech processing and the extent of this influence remains a rich area to be explored. A prerequisite for such transfer is the facilitation of greater neurophysiological overlap between speech and music processing following musical training. This review first establishes a neurophysiological link between musical training and speech perception, and subsequently provides further hypotheses on the neurophysiological implications of musical training on speech perception in adverse acoustical environments and in individuals with HL.

Using Crickets to Introduce Neurophysiology to Early Undergraduate Students

PubMed Central

Dagda, Ruben K.; Thalhauser, Rachael M.; Dagda, Raul; Marzullo, Timothy C.; Gage, Gregory J.

2013-01-01

Anatomy and physiology instructors often face the daunting task of teaching the principles of neurophysiology as part of a laboratory course with very limited resources. Teaching neurophysiology can be a difficult undertaking as sophisticated electrophysiology and data acquisition equipment is often financially out-of-reach for two-year institutions, and for many preparations, instructors need to be highly skilled in electrophysiology techniques when teaching hands-on laboratories. In the absence of appropriate laboratory tools, many undergraduate students have difficulty understanding concepts related to neurophysiology. The cricket can serve as a reliable invertebrate model to teach the basic concepts of neurophysiology in the educational laboratory. In this manuscript, we describe a series of hands-on, demonstrative, technologically simple, and affordable laboratory activities that will help undergraduate students gain an understanding of the principles of neurophysiology. By using the cerci ganglion and leg preparation, students can quantify extracellular neural activity in response to sensory stimulation, understand the principles of rate coding and somatotopy, perform electrical microstimulation to understand the threshold of sensory stimulation, and do pharmacological manipulation of neuronal activity. We describe the utility of these laboratory activities, provide a convenient protocol for quantifying extracellular recordings, and discuss feedback provided by undergraduate students with regards to the quality of the educational experience after performing the lab activities. PMID:24319394

Elucidating the neurophysiological underpinnings of autism spectrum disorder: new developments.

PubMed

Luckhardt, C; Jarczok, T A; Bender, S

2014-09-01

The study of neurophysiological approaches together with rare and common risk factors for Autism Spectrum Disorder (ASD) allows elucidating the specific underlying neurobiology of ASD. Whereas most neurophysiologically based research in ASD to date has focussed on case-control differences based on the DSM- or ICD-based categorical ASD diagnosis, more recent studies have aimed at studying genetically and/or neurophysiologically defined homogeneous ASD subgroups for specific neuronal biomarkers. This review addresses the neurophysiological investigation of ASD by evoked and event-related potentials, by EEG/MEG connectivity measures such as coherence, and transcranial magnetic stimulation. As an example of classical neurophysiological studies in ASD, we report event-related potential studies which have illustrated which brain areas and processing stages are affected in the visual perception of socially relevant stimuli. However, a paradigm shift has taken place in recent years focussing on how these findings can be tracked down to basic neuronal functions such as deficits in cortico-cortical connectivity and the interaction between brain areas. Disconnectivity, for example, can again be related to genetically induced shifts in the excitation/inhibition balance. Genetic causes of ASD may be grouped by their effects on the brain's system level to identify ASD subgroups which respond differentially to therapeutic interventions.

The contribution of clinical neurophysiology to the comprehension of the tension-type headache mechanisms.

PubMed

Rossi, Paolo; Vollono, Catello; Valeriani, Massimiliano; Sandrini, Giorgio

2011-06-01

So far, clinical neurophysiological studies on tension-type headache (TTH) have been conducted with two main purposes: (1) to establish whether some neurophysiological parameters may act as markers of TTH, and (2) to investigate the physiopathology of TTH. With regard to the first point, the present results are disappointing, since some abnormalities found in TTH patients may be frequently observed also in migraineurs. On the other hand, clinical neurophysiology has played an important role in the debate about the pathogenesis of TTH. Studies on the exteroceptive suppression of the temporalis muscle contraction have detected a dysfunction of the brainstem excitability and of its suprasegmental control. A similar conclusion has been reached by using the trigeminocervical reflexes, whose abnormalities in TTH have suggested a reduced inhibitory activity of brainstem interneurons, reflecting abnormal endogenous pain control mechanisms. It is interesting that the neural excitability abnormality in TTH seems to be a generalized phenomenon, not limited to the cranial districts. Defective DNIC-like mechanisms have indeed been evidenced also in somatic districts by nociceptive flexion reflex studies. Unfortunately, most neurophysiological studies on TTH are marred by serious methodological flaws, which should be avoided in future researches, in order to better clarify the TTH mechanisms. Copyright © 2011 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Tactile responses of hindpaw, forepaw and whisker neurons in the thalamic ventrobasal complex of anesthetized rats

PubMed Central

Aguilar, J; Morales-Botello, M L; Foffani, G

2008-01-01

The majority of studies investigating responses of thalamocortical neurons to tactile stimuli have focused on the whisker representation of the rat thalamus: the ventral–posterior–medial nucleus (VPM). To test whether the basic properties of thalamocortical responses to tactile stimuli could be extended to the entire ventrobasal complex, we recorded single neurons from the whisker, forepaw and hindpaw thalamic representations. We performed a systematic analysis of responses to stereotyped tactile stimuli − 500 ms pulses (i.e. ON–OFF stimuli) or 1 ms pulses (i.e. impulsive stimuli) − under two different anesthetics (pentobarbital or urethane). We obtained the following main results: (i) the tuning of cells to ON vs. OFF stimuli displayed a gradient across neurons, so that two-thirds of cells responded more to ON stimuli and one-third responded more to OFF stimuli; (ii) on average, response magnitudes did not differ between ON and OFF stimuli, whereas latencies of response to OFF stimuli were a few milliseconds longer; (iii) latencies of response to ON and OFF stimuli were highly correlated; (iv) responses to impulsive stimuli and ON stimuli showed a strong correlation, whereas the relationship between the responses to impulsive stimuli and OFF stimuli was subtler; (v) unlike ON responses, OFF responses did not decrease when stimuli were moved from the receptive field center to a close location in the excitatory surround. We obtained the same results for hindpaw, forepaw and whisker neurons. Our results support the view of a neurophysiologically homogeneous ventrobasal complex, in which OFF responses participate in the structure of the spatiotemporal receptive field of thalamocortical neurons for tactile stimuli. PMID:18190520

Clinical utility of EEG in diagnosing and monitoring epilepsy in adults.

PubMed

Tatum, W O; Rubboli, G; Kaplan, P W; Mirsatari, S M; Radhakrishnan, K; Gloss, D; Caboclo, L O; Drislane, F W; Koutroumanidis, M; Schomer, D L; Kasteleijn-Nolst Trenite, D; Cook, Mark; Beniczky, S

2018-05-01

Electroencephalography (EEG) remains an essential diagnostic tool for people with epilepsy (PWE). The International Federation of Clinical Neurophysiology produces new guidelines as an educational service for clinicians to address gaps in knowledge in clinical neurophysiology. The current guideline was prepared in response to gaps present in epilepsy-related neurophysiological assessment and is not intended to replace sound clinical judgement in the care of PWE. Furthermore, addressing specific pathophysiological conditions of the brain that produce epilepsy is of primary importance though is beyond the scope of this guideline. Instead, our goal is to summarize the scientific evidence for the utility of EEG when diagnosing and monitoring PWE. Copyright © 2018 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Attentional enhancement of spatial resolution: linking behavioural and neurophysiological evidence

PubMed Central

Anton-Erxleben, Katharina; Carrasco, Marisa

2014-01-01

Attention allows us to select relevant sensory information for preferential processing. Behaviourally, it improves performance in various visual tasks. One prominent effect of attention is the modulation of performance in tasks that involve the visual system’s spatial resolution. Physiologically, attention modulates neuronal responses and alters the profile and position of receptive fields near the attended location. Here, we develop a hypothesis linking the behavioural and electrophysiological evidence. The proposed framework seeks to explain how these receptive field changes enhance the visual system’s effective spatial resolution and how the same mechanisms may also underlie attentional effects on the representation of spatial information. PMID:23422910

Physiology of man and animals in the Tenth Five-Year Plan: Proceedings of the Thirteenth Congress of the I. P. Pavlov All-Union Physiological Society

NASA Technical Reports Server (NTRS)

Lange, K. A.

1980-01-01

Research in the field of animal and human physiology is reviewed. The following topics on problems of physiological science and related fields of knowledge are discussed: neurophysiology and higher nervous activity, physiology of sensory systems, physiology of visceral systems, evolutionary and ecological physiology, physiological cybernetics, computer application in physiology, information support of physiological research, history and theory of development of physiology. Also discussed were: artificial intelligence, physiological problems of reflex therapy, correlation of structure and function of the brain, adaptation and activity, microcirculation, and physiological studies in nerve and mental diseases.

From perceptive fields to Gestalt.

PubMed

Spillmann, Lothar

2006-01-01

Studies on visual psychophysics and perception conducted in the Freiburg psychophysics laboratory during the last 35 years are reviewed. Many of these were inspired by single-cell neurophysiology in cat and monkey. The aim was to correlate perceptual phenomena and their effects to possible neuronal mechanisms from retina to visual cortex and beyond. Topics discussed include perceptive field organization, figure-ground segregation and grouping, fading and filling-in, and long-range color interaction. While some of these studies succeeded in linking perception to neuronal response patterns, others require further investigation. The task of probing the human brain with perceptual phenomena continues to be a challenge for the future.

Optional real-time display of intraoperative neurophysiological monitoring in the microscopic field of view: avoiding communication failures in the operating room.

PubMed

Stoecklein, Veit M; Faber, Florian; Koch, Mandy; Mattmüller, Rudi; Schaper, Anika; Rudolph, Frank; Tonn, Joerg C; Schichor, Christian

2015-11-01

The use of intraoperative neurophysiological monitoring (IONM) in neurosurgery has improved patient safety and outcomes. However, a pitfall in the use of IONM remains unsolved. Currently, there is no feasible way for surgeons to interpret IONM waves themselves during operations. Instead, they have to rely on verbal feedback from a neurophysiologist. This method is prone to communication failures, which can lead to delayed or false interpretation of the data. Direct visualization of IONM waves is a way to alleviate this problem and make IONM more effective. Microscope-integrated IONM (MI-IONM) was used in 163 cranial and spinal cases. We evaluated the feasibility, system stability and how well the system integrated into the surgical workflow. We used an IONM system that was connected to a surgical microscope. All IONM modalities used at our institution could be visualized as required, superimposed on the surgical field in the eyepiece of the microscope without obstructing the surgeon's field of vision. Use of MI-IONM was safe and reliable. It furthermore provided valuable intraoperative information. The system merely required a short learning curve. Only minor system problems without impact on surgical workflow occurred. MI-IONM proved to be especially useful in surgical cases where careful monitoring of nerve function is required, e.g., cerebellopontine angle surgery. Here, direct assessment of surgical action and IONM wave change was provided to the surgeon, if necessary (on-off control). MI-IONM is a useful extension of conventional IONM that provides optional real-time functional information to the surgeon on demand.

Electroencephalography Predicts Poor and Good Outcomes After Cardiac Arrest: A Two-Center Study.

PubMed

Rossetti, Andrea O; Tovar Quiroga, Diego F; Juan, Elsa; Novy, Jan; White, Roger D; Ben-Hamouda, Nawfel; Britton, Jeffrey W; Oddo, Mauro; Rabinstein, Alejandro A

2017-07-01

The prognostic role of electroencephalography during and after targeted temperature management in postcardiac arrest patients, relatively to other predictors, is incompletely known. We assessed performances of electroencephalography during and after targeted temperature management toward good and poor outcomes, along with other recognized predictors. Cohort study (April 2009 to March 2016). Two academic hospitals (Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland; Mayo Clinic, Rochester, MN). Consecutive comatose adults admitted after cardiac arrest, identified through prospective registries. All patients were managed with targeted temperature management, receiving prespecified standardized clinical, neurophysiologic (particularly, electroencephalography during and after targeted temperature management), and biochemical evaluations. We assessed electroencephalography variables (reactivity, continuity, epileptiform features, and prespecified "benign" or "highly malignant" patterns based on the American Clinical Neurophysiology Society nomenclature) and other clinical, neurophysiologic (somatosensory-evoked potential), and biochemical prognosticators. Good outcome (Cerebral Performance Categories 1 and 2) and mortality predictions at 3 months were calculated. Among 357 patients, early electroencephalography reactivity and continuity and flexor or better motor reaction had greater than 70% positive predictive value for good outcome; reactivity (80.4%; 95% CI, 75.9-84.4%) and motor response (80.1%; 95% CI, 75.6-84.1%) had highest accuracy. Early benign electroencephalography heralded good outcome in 86.2% (95% CI, 79.8-91.1%). False positive rates for mortality were less than 5% for epileptiform or nonreactive early electroencephalography, nonreactive late electroencephalography, absent somatosensory-evoked potential, absent pupillary or corneal reflexes, presence of myoclonus, and neuron-specific enolase greater than 75 µg/L; accuracy was highest for early electroencephalography reactivity (86.6%; 95% CI, 82.6-90.0). Early highly malignant electroencephalography had an false positive rate of 1.5% with accuracy of 85.7% (95% CI, 81.7-89.2%). This study provides class III evidence that electroencephalography reactivity predicts both poor and good outcomes, and motor reaction good outcome after cardiac arrest. Electroencephalography reactivity seems to be the best discriminator between good and poor outcomes. Standardized electroencephalography interpretation seems to predict both conditions during and after targeted temperature management.

Age-Matched Comparison of Elite and Non-elite Military Performers during Free Living and Intense Operational Stress

DTIC Science & Technology

2009-04-08

military domain, Morgan et al. (2007) examined heart rate variability ( HRV ) as a predictor of performance during extreme military training. These scientists...the HRV analyses were performed during classroom phases of training, just prior to the stressful field exercises. These observations, then, may not...defense: fear/ anxiety and defensive distance. Neurosci Biobehav Rev, 28(3), 285-305. 21. Taylor MK, Sausen KP, Mujica-Parodi LR, et al: Neurophysiologic

Evaluation of Neurophysiologic and Systematic Changes during Aeromedical Evacuation and en Route Care of Combat Casualties in a Swine Polytrauma

DTIC Science & Technology

2015-02-01

of Combat Casualties in a Swine Polytrauma PRINCIPAL INVESTIGATOR: Richard McCarron, PhD CONTRACTING ORGANIZATION: Henry M. Jackson Foundation for the...Neurophysiologic and Systematic Changes during Aeromedical Evacuation and en Route Care of Combat Casualties in a Swine Polytrauma 5a. CONTRACT NUMBER...of neurotrauma and polytrauma . We plan to investigate the effects of aero-medical evacuation on neurophysiology and lung function in swine models of

Application of Higuchi's fractal dimension from basic to clinical neurophysiology: A review.

PubMed

Kesić, Srdjan; Spasić, Sladjana Z

2016-09-01

For more than 20 years, Higuchi's fractal dimension (HFD), as a nonlinear method, has occupied an important place in the analysis of biological signals. The use of HFD has evolved from EEG and single neuron activity analysis to the most recent application in automated assessments of different clinical conditions. Our objective is to provide an updated review of the HFD method applied in basic and clinical neurophysiological research. This article summarizes and critically reviews a broad literature and major findings concerning the applications of HFD for measuring the complexity of neuronal activity during different neurophysiological conditions. The source of information used in this review comes from the PubMed, Scopus, Google Scholar and IEEE Xplore Digital Library databases. The review process substantiated the significance, advantages and shortcomings of HFD application within all key areas of basic and clinical neurophysiology. Therefore, the paper discusses HFD application alone, combined with other linear or nonlinear measures, or as a part of automated methods for analyzing neurophysiological signals. The speed, accuracy and cost of applying the HFD method for research and medical diagnosis make it stand out from the widely used linear methods. However, only a combination of HFD with other nonlinear methods ensures reliable and accurate analysis of a wide range of neurophysiological signals. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Standard operating procedures for neurophysiologic assessment of male sexual dysfunction.

PubMed

Giuliano, Francois; Rowland, David L

2013-05-01

Can neurophysiological testing in male patients with sexual dysfunction benefit the decision-making process? The answer remains unclear. To provide standard operating procedures for the neurophysiologic assessment of male sexual dysfunction. Medical literature was reviewed and combined with expert opinion of the authors. Bulbocavernosus reflex latency time, pudendal somatosensory evoked potentials, and sympathetic skin responses have been considered as potential candidates for the diagnosis and assessment of erectile dysfunction (ED). Currently, there is no consensus on a standardized methodology for these neurophysiological investigations in the overall assessment of ED. These procedures are unable to assess the integrity of the efferent parasympathetic proerectile penile innervation; accordingly, none of these assessment procedures is recommended for ED patients. Corpus cavernosum electromyography (CC-EMG) can detect abnormalities in cavernous smooth muscle although these alterations can be attributed both to damage to autonomic penile innervation and to degenerative processes of the cavernous smooth muscle. CC-EMG is still considered experimental. Evidence does not support that men with premature ejaculation (PE) are consistently characterized by penile hypersensitivity; accordingly, penile threshold determination is not recommended to in the diagnosis of PE. Neurophysiological investigation of other components of the penile sensory pathways in PE patients has not provided any definitive contribution to the diagnosis. No neurophysiological assessment procedures yield additional information that consistently aids in the assessment of PE and ED. © 2013 International Society for Sexual Medicine.

Tactile event-related potentials in amyotrophic lateral sclerosis (ALS): Implications for brain-computer interface.

PubMed

Silvoni, S; Konicar, L; Prats-Sedano, M A; Garcia-Cossio, E; Genna, C; Volpato, C; Cavinato, M; Paggiaro, A; Veser, S; De Massari, D; Birbaumer, N

2016-01-01

We investigated neurophysiological brain responses elicited by a tactile event-related potential paradigm in a sample of ALS patients. Underlying cognitive processes and neurophysiological signatures for brain-computer interface (BCI) are addressed. We stimulated the palm of the hand in a group of fourteen ALS patients and a control group of ten healthy participants and recorded electroencephalographic signals in eyes-closed condition. Target and non-target brain responses were analyzed and classified offline. Classification errors served as the basis for neurophysiological brain response sub-grouping. A combined behavioral and quantitative neurophysiological analysis of sub-grouped data showed neither significant between-group differences, nor significant correlations between classification performance and the ALS patients' clinical state. Taking sequential effects of stimuli presentation into account, analyses revealed mean classification errors of 19.4% and 24.3% in healthy participants and ALS patients respectively. Neurophysiological correlates of tactile stimuli presentation are not altered by ALS. Tactile event-related potentials can be used to monitor attention level and task performance in ALS and may constitute a viable basis for future BCIs. Implications for brain-computer interface implementation of the proposed method for patients in critical conditions, such as the late stage of ALS and the (completely) locked-in state, are discussed. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Evidence that transcranial direct current stimulation (tDCS) generates little-to-no reliable neurophysiologic effect beyond MEP amplitude modulation in healthy human subjects: A systematic review.

PubMed

Horvath, Jared Cooney; Forte, Jason D; Carter, Olivia

2015-01-01

Transcranial direct current stimulation (tDCS) is a form of neuromodulation that is increasingly being utilized to examine and modify a number of cognitive and behavioral measures. The theoretical mechanisms by which tDCS generates these changes are predicated upon a rather large neurophysiological literature. However, a robust systematic review of this neurophysiological data has not yet been undertaken. tDCS data in healthy adults (18-50) from every neurophysiological outcome measure reported by at least two different research groups in the literature was collected. When possible, data was pooled and quantitatively analyzed to assess significance. When pooling was not possible, data was qualitatively compared to assess reliability. Of the 30 neurophysiological outcome measures reported by at least two different research groups, tDCS was found to have a reliable effect on only one: MEP amplitude. Interestingly, the magnitude of this effect has been significantly decreasing over the last 14 years. Our systematic review does not support the idea that tDCS has a reliable neurophysiological effect beyond MEP amplitude modulation - though important limitations of this review (and conclusion) are discussed. This work raises questions concerning the mechanistic foundations and general efficacy of this device - the implications of which extend to the steadily increasing tDCS psychological literature. Copyright © 2014 Elsevier Ltd. All rights reserved.

A randomized controlled trial of intensive neurophysiology education in chronic low back pain.

PubMed

Moseley, G Lorimer; Nicholas, Michael K; Hodges, Paul W

2004-01-01

Cognitive-behavioral pain management programs typically achieve improvements in pain cognitions, disability, and physical performance. However, it is not known whether the neurophysiology education component of such programs contributes to these outcomes. In chronic low back pain patients, we investigated the effect of neurophysiology education on cognitions, disability, and physical performance. This study was a blinded randomized controlled trial. Individual education sessions on neurophysiology of pain (experimental group) and back anatomy and physiology (control group) were conducted by trained physical therapist educators. Cognitions were evaluated using the Survey of Pain Attitudes (revised) (SOPA(R)), and the Pain Catastrophizing Scale (PCS). Behavioral measures included the Roland Morris Disability Questionnaire (RMDQ), and 3 physical performance tasks; (1) straight leg raise (SLR), (2) forward bending range, and (3) an abdominal "drawing-in" task, which provides a measure of voluntary activation of the deep abdominal muscles. Methodological checks evaluated non-specific effects of intervention. There was a significant treatment effect on the SOPA(R), PCS, SLR, and forward bending. There was a statistically significant effect on RMDQ; however, the size of this effect was small and probably not clinically meaningful. Education about pain neurophysiology changes pain cognitions and physical performance but is insufficient by itself to obtain a change in perceived disability. The results suggest that pain neurophysiology education, but not back school type education, should be included in a wider pain management approach.

Aging and emotional memory: the co-occurrence of neurophysiological and behavioral positivity effects.

PubMed

Langeslag, Sandra J E; van Strien, Jan W

2009-06-01

The positivity effect is a trend for adults to increasingly process positive and/or decreasingly process negative information compared with other information with advancing age. The positivity effect has been observed with behavioral measures, such as in attention and memory tests, and with measures of neurophysiological activity, such as in amygdala activation and the late positive potential (LPP). In this study, it was investigated whether these behavioral and neurophysiological positivity effects co-occur. The electroencephalogram of younger (19-26 years) and older (65-82 years) adults was recorded while they encoded unpleasant, neutral, and pleasant pictures for retrieval in free and cued recall tests. Positivity effects occurred in the late LPP amplitude (700-1,000 ms) and in the free recall test, with negativity biases in younger adults and no biases in older adults. The occurrence of a valence bias in the LPP was substantially but nonsignificantly correlated with the occurrence of a similar valence bias in memory in the older adults. In conclusion, neurophysiological and behavioral positivity effects appear to co-occur, a finding that awaits expansion using different neurophysiological and behavioral measures.

The Trier Social Stress Test as a paradigm to study how people respond to threat in social interactions

PubMed Central

Frisch, Johanna U.; Häusser, Jan A.; Mojzisch, Andreas

2015-01-01

In our lives, we face countless situations in which we are observed and evaluated by our social interaction partners. Social-evaluative threat is frequently associated with strong neurophysiological stress reactions, in particular, an increase in cortisol levels. Yet, social variables do not only cause stress, but they can also buffer the neurophysiological stress response. Furthermore, social variables can themselves be affected by the threat or the threat-induced neurophysiological stress response. In order to study this complex interplay of social-evaluative threat, social processes and neurophysiological stress responses, a paradigm is needed that (a) reliably induces high levels of social-evaluative threat and (b) is extremely adaptable to the needs of the researcher. The Trier Social Stress Test (TSST) is a well-established paradigm in biopsychology that induces social-evaluative threat in the laboratory by subjecting participants to a mock job-interview. In this review, we aim at demonstrating the potential of the TSST for studying the complex interplay of social-evaluative threat, social processes and neurophysiological stress responses. PMID:25698987

Neurophysiology of the pelvic floor in clinical practice: a systematic literature review

PubMed Central

Bianchi, Francesca; Squintani, Giovanna Maddalena; Osio, Maurizio; Morini, Alberto; Bana, Cristina; Ardolino, Gianluca; Barbieri, Sergio; Bertolasi, Laura; Caramelli, Riccardo; Cogiamanian, Filippo; Currà, Antonio; de Scisciolo, Giuseppe; Foresti, Camillo; Frasca, Vittorio; Frasson, Emma; Inghilleri, Maurizio; Maderna, Luca; Motti, Luisa; Onesti, Emanuela; Romano, Marcello Calogero; Del Carro, Ubaldo

2017-01-01

Summary Neurophysiological testing of the pelvic floor is recognized as an essential tool to identify pathophysiological mechanisms of pelvic floor disorders, support clinical diagnosis, and aid in therapeutic decisions. Nevertheless, the diagnostic value of these tests in specific neurological diseases of the pelvic floor is not completely clarified. Seeking to fill this gap, the members of the Neurophysiology of the Pelvic Floor Study Group of the Italian Clinical Neurophysiology Society performed a systematic review of the literature to gather available evidence for and against the utility of neurophysiological tests. Our findings confirm the utility of some tests in specific clinical conditions [e.g. concentric needle electromyography, evaluation of sacral reflexes and of pudendal somatosensory evoked potentials (pSEPs) in cauda equina and conus medullaris lesions, and evaluation of pSEPs and perineal sympathetic skin response in spinal cord lesions], and support their use in clinical practice. Other tests, particularly those not currently supported by high-level evidence, when employed in individual patients, should be evaluated in the overall clinical context, or otherwise used for research purposes.

Neurophysiology of pain and hypnosis for chronic pain.

PubMed

Dillworth, Tiara; Mendoza, M Elena; Jensen, Mark P

2012-03-01

In the past decade there has been a dramatic increase in (1) understanding the neurophysiological components of the pain experiences, (2) randomized clinical trials testing the efficacy of hypnotic treatments on chronic pain, and (3) laboratory research examining the effects of hypnosis on the neurophysiological processes implicated in pain. Work done in these areas has not only demonstrated the efficacy of hypnosis for treating chronic pain but is beginning to shed light on neurophysiological processes that may play a role in its effectiveness. This paper reviews a selection of published studies from these areas of research, focusing on recent findings that have the most potential to inform both clinical work and research in this area. The paper concludes with research and clinical recommendations for maximizing treatment efficacy based on the research findings that are available.

Magnetic fields in noninvasive brain stimulation.

PubMed

Vidal-Dourado, Marcos; Conforto, Adriana Bastos; Caboclo, Luis Otávio Sales Ferreira; Scaff, Milberto; Guilhoto, Laura Maria de Figueiredo Ferreira; Yacubian, Elza Márcia Targas

2014-04-01

The idea that magnetic fields could be used therapeutically arose 2000 years ago. These therapeutic possibilities were expanded after the discovery of electromagnetic induction by the Englishman Michael Faraday and the American Joseph Henry. In 1896, Arsène d'Arsonval reported his experience with noninvasive brain magnetic stimulation to the scientific French community. In the second half of the 20th century, changing magnetic fields emerged as a noninvasive tool to study the nervous system and to modulate neural function. In 1985, Barker, Jalinous, and Freeston presented transcranial magnetic stimulation, a relatively focal and painless technique. Transcranial magnetic stimulation has been proposed as a clinical neurophysiology tool and as a potential adjuvant treatment for psychiatric and neurologic conditions. This article aims to contextualize the progress of use of magnetic fields in the history of neuroscience and medical sciences, until 1985.

Preliminary evidence of a neurophysiological basis for individual discrimination in filial imprinting.

PubMed

Town, Stephen Michael

2011-12-01

Filial imprinting involves a predisposition for biologically important stimuli and a learning process directing preferences towards a particular stimulus. Learning underlies discrimination between imprinted and unfamiliar individuals and depends upon the IMM (intermediate and medial mesopallium). Here, IMM neurons responded differentially to familiar and unfamiliar conspecifics following socialization and the neurophysiological effects of social experience differed between hemispheres. Such findings may provide a neurophysiological basis for individual discrimination in imprinting. Copyright © 2011 Elsevier B.V. All rights reserved.

Peripheral nervous system involvement in essential cryoglobulinemia and nephropathy.

PubMed

Valli, G; De Vecchi, A; Gaddi, L; Nobile-Orazio, E; Tarantino, A; Barbieri, S

1989-01-01

The clinical and neurophysiological features of 23 patients affected by essential cryoglobulinemia (EC) have been studied. It was possible to perform sural nerve biopsy in 3 cases. Six patients were found to be affected by a peripheral neuropathy, according to the WHO criteria, while in 8 other patients clinical and neurophysiological signs of a milder peripheral nervous system (PNS) involvement were evident. The incidence of PNS involvement seems to be high (60.9%). Neurophysiological and histological studies were indicative of a mainly axonal damage.

Music Evolution in the Laboratory: Cultural Transmission Meets Neurophysiology

PubMed Central

Lumaca, Massimo; Ravignani, Andrea; Baggio, Giosuè

2018-01-01

In recent years, there has been renewed interest in the biological and cultural evolution of music, and specifically in the role played by perceptual and cognitive factors in shaping core features of musical systems, such as melody, harmony, and rhythm. One proposal originates in the language sciences. It holds that aspects of musical systems evolve by adapting gradually, in the course of successive generations, to the structural and functional characteristics of the sensory and memory systems of learners and “users” of music. This hypothesis has found initial support in laboratory experiments on music transmission. In this article, we first review some of the most important theoretical and empirical contributions to the field of music evolution. Next, we identify a major current limitation of these studies, i.e., the lack of direct neural support for the hypothesis of cognitive adaptation. Finally, we discuss a recent experiment in which this issue was addressed by using event-related potentials (ERPs). We suggest that the introduction of neurophysiology in cultural transmission research may provide novel insights on the micro-evolutionary origins of forms of variation observed in cultural systems. PMID:29713263

Probing sensorimotor integration during musical performance.

PubMed

Furuya, Shinichi; Furukawa, Yuta; Uehara, Kazumasa; Oku, Takanori

2018-03-10

An integration of afferent sensory information from the visual, auditory, and proprioceptive systems into execution and update of motor programs plays crucial roles in control and acquisition of skillful sequential movements in musical performance. However, conventional behavioral and neurophysiological techniques that have been applied to study simplistic motor behaviors limit elucidating online sensorimotor integration processes underlying skillful musical performance. Here, we propose two novel techniques that were developed to investigate the roles of auditory and proprioceptive feedback in piano performance. First, a closed-loop noninvasive brain stimulation system that consists of transcranial magnetic stimulation, a motion sensor, and a microcomputer enabled to assess time-varying cortical processes subserving auditory-motor integration during piano playing. Second, a force-field system capable of manipulating the weight of a piano key allowed for characterizing movement adaptation based on the feedback obtained, which can shed light on the formation of an internal representation of the piano. Results of neurophysiological and psychophysics experiments provided evidence validating these systems as effective means for disentangling computational and neural processes of sensorimotor integration in musical performance. © 2018 New York Academy of Sciences.

Music Evolution in the Laboratory: Cultural Transmission Meets Neurophysiology.

PubMed

Lumaca, Massimo; Ravignani, Andrea; Baggio, Giosuè

2018-01-01

In recent years, there has been renewed interest in the biological and cultural evolution of music, and specifically in the role played by perceptual and cognitive factors in shaping core features of musical systems, such as melody, harmony, and rhythm. One proposal originates in the language sciences. It holds that aspects of musical systems evolve by adapting gradually, in the course of successive generations, to the structural and functional characteristics of the sensory and memory systems of learners and "users" of music. This hypothesis has found initial support in laboratory experiments on music transmission. In this article, we first review some of the most important theoretical and empirical contributions to the field of music evolution. Next, we identify a major current limitation of these studies, i.e., the lack of direct neural support for the hypothesis of cognitive adaptation. Finally, we discuss a recent experiment in which this issue was addressed by using event-related potentials (ERPs). We suggest that the introduction of neurophysiology in cultural transmission research may provide novel insights on the micro-evolutionary origins of forms of variation observed in cultural systems.

Quantum Social Science

NASA Astrophysics Data System (ADS)

Haven, Emmanuel; Khrennikov, Andrei

2013-01-01

Preface; Part I. Physics Concepts in Social Science? A Discussion: 1. Classical, statistical and quantum mechanics: all in one; 2. Econophysics: statistical physics and social science; 3. Quantum social science: a non-mathematical motivation; Part II. Mathematics and Physics Preliminaries: 4. Vector calculus and other mathematical preliminaries; 5. Basic elements of quantum mechanics; 6. Basic elements of Bohmian mechanics; Part III. Quantum Probabilistic Effects in Psychology: Basic Questions and Answers: 7. A brief overview; 8. Interference effects in psychology - an introduction; 9. A quantum-like model of decision making; Part IV. Other Quantum Probabilistic Effects in Economics, Finance and Brain Sciences: 10. Financial/economic theory in crisis; 11. Bohmian mechanics in finance and economics; 12. The Bohm-Vigier Model and path simulation; 13. Other applications to economic/financial theory; 14. The neurophysiological sources of quantum-like processing in the brain; Conclusion; Glossary; Index.

Effects of prenatal irradiation with an accelerated heavy-ion beam on postnatal development in rats: II. Further study on neurophysiologic alterations

NASA Astrophysics Data System (ADS)

Wang, B.; Murakami, M.; Eguchi-Kasai, K.; Nojima, K.; Shang, Y.; Tanaka, K.; Watanabe, K.; Fujita, K.; Moreno, S. G.; Coffigny, H.; Hayata, I.

Organogenesis is a highly radiosensitive period, study of prenatal exposure to high LET heavy ion beams on postnatal development is important for clarifying the radiation risk in space and promoting the evidence-based mechanism research. The effects from heavy ion irradiations are not well studied as those for low LET radiations such as X-rays in this field, even the ground-based investigations remain to be addressed. Using the Heavy Ion Medical Accelerator in Chiba (HIMAC) and Wistar rats, postnatal neurophysiological development in offspring was investigated following exposure of pregnant rats to accelerated neon-ion beams with a LET value of about 30 keV/μm at a dose range from 0.1 to 2.0 Gy on the 15th day of gestation. The age for appearance of four physiologic markers and attainment of five neonatal reflexes, and gain in body weight were monitored. Male offspring were evaluated as young adults using two behavioral tests including open field and hole-board dipping tests. The effects of X-rays at 200 kVp measured for the same biological end points were studied for comparison. For most of the endpoints at early age, significant neurophysiological alteration was observed even in offspring receiving 0.1 Gy of accelerated neon ions but not X-rays. All offspring receiving 2.0 Gy of accelerated neon ions died prior to weaning. Offspring prenatally irradiated with neon ions generally showed higher incidences of prenatal death, increased preweaning mortality, markedly delayed accomplishment in physiological markers and reflexes, significantly lower body weight and reduced ratios of main organ weight to body weight, and altered behavior compared to those exposed to X-rays at doses of 0.1 1.5 Gy. These findings indicate that irradiations with neon ions at 0.1 1.5 Gy on day 15 of gestation caused varied developmental alterations in offspring, and efficient dose leading to the detrimental effects seemed to be lower than that of X-rays.

The Psychoanalytic Concept of Jouissance and the Kindling Hypothesis

PubMed Central

Dimitriadis, Yorgos

2017-01-01

This article aims to define the conceptual field of jouissance in Lacanian theory, and put forth the hypothesis of a relationship between certain neurophysiological mechanisms and specific clinical phenomena where jouissance is “kindled” and outside the control of the symbolic process. First, the author briefly introduces Lacan's notion of jouissance and the way it draws on Freud's theorization, and describes the preliminary stages of this conceptual field in Lacan's work. Then, the jouissance related to two other concepts: repetition, with its Freudian and Lacanian nuances, as well as the—exclusively—Lacanian concept of the object petit a. Lacan's later conceptualization of language as jouissance (the notion of lalangue) is then discussed in relation to Freud's early ideas (“Letter 52”) on the different kinds of inscriptions that help form the mental apparatus. Finally, the author tries to formulate a hypothesis regarding specific neurophysiological mechanisms, based on clinical situations where jouissance becomes “kindled” and escapes the control of the symbolic processes through the neurophysiological mechanisms of conditioning, “kindling-sensitization” and “excitotoxicity.” In these cases, jouissance can have a destructive effect on the body and can affect, among others organs, the brain—a process the author has previously described heuristically as the “psychosomatic diseases of the brain.” This would be a special mechanism of automatism that would be triggered under the specific conditions of the fragility of the signifying chain (foreclosure of the Name-of-the-Father or solidification of the signifying chain) in combination with biological factors, including genetic factors. In this process, signifiers are reduced to signals, which in turn may be reduced to stimuli, with a tendency toward self-perpetuation, while affects are reduced to emotions and moods. Thus, conditioning and kindling-sensitization could also be understood in terms of a “semiotic reduction.” Can we therefore consider that certain phenomena of automatism and certain deficits (delusional moods, schizophrenic apathy, etc.) could be seen as psychosomatic disorders of the brain? The phenomena in question might also serve—albeit at random—as a kind of shield to mitigate excessive jouissance. PMID:28983266

[Anaesthetic management of excision of a cervical intraspinal tumor with intraoperative neurophysiologic monitoring in a pregnant woman at 29 weeks].

PubMed

Guerrero-Domínguez, R; González-González, G; Rubio-Romero, R; Federero-Martínez, F; Jiménez, I

2016-05-01

The intraoperative neurophysiological monitoring is a technique used to test and monitor nervous function. This technique has become essential in some neurosurgery interventions, since it avoids neurological injuries during surgery and reduces morbidity. The experience of intraoperative neurophysiological monitoring is limited in some clinical cases due to the low incidence of pregnant women undergoing a surgical procedure. A case is presented of a 29-weeks pregnant woman suffering from a cervical intraspinal tumour with intense pain, which required surgery. The collaboration of a multidisciplinary team composed of anaesthesiologists, neurosurgeons, neurophysiologists and obstetricians, the continuous monitoring of the foetus, the intraoperative neurophysiological monitoring, and maintaining the neurophysiological and utero-placental variables were crucial for the proper development of the surgery. According to our experience and the limited publications in the literature, no damaging effects of this technique were detected at maternal-foetal level. On the contrary, it brings important benefits during the surgery and for the final result. Copyright © 2015 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

A systems neurophysiology approach to voluntary event coding.

PubMed

Petruo, Vanessa A; Stock, Ann-Kathrin; Münchau, Alexander; Beste, Christian

2016-07-15

Mechanisms responsible for the integration of perceptual events and appropriate actions (sensorimotor processes) have been subject to intense research. Different theoretical frameworks have been put forward with the "Theory of Event Coding (TEC)" being one of the most influential. In the current study, we focus on the concept of 'event files' within TEC and examine what sub-processes being dissociable by means of cognitive-neurophysiological methods are involved in voluntary event coding. This was combined with EEG source localization. We also introduce reward manipulations to delineate the neurophysiological sub-processes most relevant for performance variations during event coding. The results show that processes involved in voluntary event coding included predominantly stimulus categorization, feature unbinding and response selection, which were reflected by distinct neurophysiological processes (the P1, N2 and P3 ERPs). On a system's neurophysiological level, voluntary event-file coding is thus related to widely distributed parietal-medial frontal networks. Attentional selection processes (N1 ERP) turned out to be less important. Reward modulated stimulus categorization in parietal regions likely reflecting aspects of perceptual decision making but not in other processes. The perceptual categorization stage appears central for voluntary event-file coding. Copyright © 2016 Elsevier Inc. All rights reserved.

Unraveling the barriers to reconceptualization of the problem in chronic pain: the actual and perceived ability of patients and health professionals to understand the neurophysiology.

PubMed

Moseley, Lorimer

2003-05-01

To identify why reconceptualization of the problem is difficult in chronic pain, this study aimed to evaluate whether (1) health professionals and patients can understand currently accurate information about the neurophysiology of pain and (2) health professionals accurately estimate the ability of patients to understand the neurophysiology of pain. Knowledge tests were completed by 276 patients with chronic pain and 288 professionals either before (untrained) or after (trained) education about the neurophysiology of pain. Professionals estimated typical patient performance on the test. Untrained participants performed poorly (mean +/- standard deviation, 55% +/- 19% and 29% +/- 12% for professionals and patients, respectively), compared to their trained counterparts (78% +/- 21% and 61% +/- 19%, respectively). The estimated patient score (46% +/- 18%) was less than the actual patient score (P <.005). The results suggest that professionals and patients can understand the neurophysiology of pain but professionals underestimate patients' ability to understand. The implications are that (1) a poor knowledge of currently accurate information about pain and (2) the underestimation of patients' ability to understand currently accurate information about pain represent barriers to reconceptualization of the problem in chronic pain within the clinical and lay arenas.

Pathophysiology of pain in postherpetic neuralgia: a clinical and neurophysiological study.

PubMed

Truini, A; Galeotti, F; Haanpaa, M; Zucchi, R; Albanesi, A; Biasiotta, A; Gatti, A; Cruccu, G

2008-12-01

Postherpetic neuralgia is an exceptionally drug-resistant neuropathic pain. To investigate the pathophysiological mechanisms underlying postherpetic neuralgia we clinically investigated sensory disturbances, pains and itching, with an 11-point numerical rating scale in 41 patients with ophthalmic postherpetic neuralgia. In all the patients we recorded the blink reflex, mediated by non-nociceptive myelinated Abeta-fibers, and trigeminal laser evoked potentials (LEPs) related to nociceptive myelinated Adelta- and unmyelinated C-fiber activation. We also sought possible correlations between clinical sensory disturbances and neurophysiological data. Neurophysiological testing yielded significantly abnormal responses on the affected side compared with the normal side (P<0.001). The blink reflex delay correlated with the intensity of paroxysmal pain, whereas the Adelta- and C-LEP amplitude reduction correlated with the intensity of constant pain (P<0.01). Allodynia correlated with none of the neurophysiological data. Our study shows that postherpetic neuralgia impairs all sensory fiber groups. The neurophysiological-clinical correlations suggest that constant pain arises from a marked loss of nociceptive afferents, whereas paroxysmal pain is related to Abeta-fiber demyelination. These findings might be useful for a better understanding of pain mechanisms in postherpetic neuralgia.

Magnetic field effects on electron transfer reactions involving sextet-spin ( S = 5/2) intermediates generated on photoexcitation of a Cr(III)-porphyrin complex

NASA Astrophysics Data System (ADS)

Mori, Yukie; Hoshino, Mikio; Hayashi, Hisaharu

The excited trip-sextet ( 6 T 1 ) state of chloro-(3-methylimidazol)-( meso -tetraphenylporphyrinato) chromium(III) (Cr III P) is quenched by 1,1 '-dibenzyl-4,4 '-bipyridinium (BV 2+ ) in acetonitrile through electron transfer to give 5 (Cr III P .+ ) and 2 BV .+ . The intermediate is a geminate ion pair in the sextet (Sx) state 6 [ 5 (Cr III P .+ ) 2 BV .+ ], which decays through either the escape from a solvent cage to give the free ions or the spin conversion to the quartet (Qa) state followed by back electron transfer. The free ion yield ( ΦFI ) increased with increasing magnetic field from 0 to 4 T and then slightly decreased from 4 T to 10 T. These magnetic field effects are explained as follows. Under low fields where the Zeeman splitting of the spin sublevels is lower than or comparable with the electron spin dipole-dipole interaction within 5 (Cr III P .+ ), this interaction effectively induces the Sx ⇔Qa conversion of [ 5 (Cr III P .+ ) 2 BV + ] to result in low ΦFI values. Under high fields where the Zeeman splitting is larger than the dipole-dipole interaction, the Sx Qa conversion is decreased with increasing field to cause higher ΦFI values. The slight decrease in ΦFI above 4 T may be due to the Δg mechanism.

NEUROPHYSIOLOGICAL EVALUATION OF SENSORY SYSTEMS'

EPA Science Inventory

Exposure to many neurotoxic compounds has been shown to produce a sensory system dysfunction. Neurophysiological assessment of sensory function in humans and animal models often uses techniques known as sensory evoked potentials. Because both humans and animals show analogous res...

Tonic pain and continuous EEG: prediction of subjective pain perception by alpha-1 power during stimulation and at rest.

PubMed

Nir, Rony-Reuven; Sinai, Alon; Moont, Ruth; Harari, Eyal; Yarnitsky, David

2012-03-01

Pain neurophysiology has been chiefly characterized via event-related potentials (ERPs), which are exerted using brief, phase-locked noxious stimuli. Striving for objectively characterizing clinical pain states using more natural, prolonged stimuli, tonic pain has been recently associated with the individual peak frequency of alpha oscillations. This finding encouraged us to explore whether alpha power, reflecting the magnitude of the synchronized activity within this frequency range, will demonstrate a corresponding relationship with subjective perception of tonic pain. Five-minute-long continuous EEG was recorded in 18 healthy volunteers under: (i) resting-state; (ii) innocuous temperature; and (iii) psychophysically-anchored noxious temperature. Numerical pain scores (NPSs) collected during the application of tonic noxious stimuli were tested for correlation with alpha-1 and alpha-2 power. NPSs and alpha power remained stable throughout the recording conditions (Ps⩾0.381). In the noxious condition, alpha-1 power obtained at the bilateral temporal scalp was negatively correlated with NPSs (Ps⩽0.04). Additionally, resting-state alpha-1 power recorded at the bilateral temporal scalp was negatively correlated with NPSs reported during the noxious condition (Ps⩽0.038). Current findings suggest alpha-1 power may serve as a direct, objective and experimentally stable measure of subjective perception of tonic pain. Furthermore, resting-state alpha-1 power might reflect individuals' inherent tonic pain responsiveness. The relevance of alpha-1 power to tonic pain perception may deepen the understanding of the mechanisms underlying the processing of prolonged noxious stimulation. Copyright © 2011 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Resting-State Neurophysiological Activity Patterns in Young People with ASD, ADHD, and ASD + ADHD.

PubMed

Shephard, Elizabeth; Tye, Charlotte; Ashwood, Karen L; Azadi, Bahar; Asherson, Philip; Bolton, Patrick F; McLoughlin, Grainne

2018-01-01

Altered power of resting-state neurophysiological activity has been associated with autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD), which commonly co-occur. We compared resting-state neurophysiological power in children with ASD, ADHD, co-occurring ASD + ADHD, and typically developing controls. Children with ASD (ASD/ASD + ADHD) showed reduced theta and alpha power compared to children without ASD (controls/ADHD). Children with ADHD (ADHD/ASD + ADHD) displayed decreased delta power compared to children without ADHD (ASD/controls). Children with ASD + ADHD largely presented as an additive co-occurrence with deficits of both disorders, although reduced theta compared to ADHD-only and reduced delta compared to controls suggested some unique markers. Identifying specific neurophysiological profiles in ASD and ADHD may assist in characterising more homogeneous subgroups to inform treatment approaches and aetiological investigations.

Qualitative and quantitative aspects of information processing in first psychosis: latent class analyses in patients, at-risk subjects, and controls.

PubMed

van Tricht, Mirjam J; Bour, Lo J; Koelman, Johannes H T M; Derks, Eske M; Braff, David L; de Wilde, Odette M; Boerée, Thijs; Linszen, Don H; de Haan, Lieuwe; Nieman, Dorien H

2015-04-01

We aimed to determine profiles of information processing deficits in the pathway to first psychosis. Sixty-one subjects at ultrahigh risk (UHR) for psychosis were assessed, of whom 18 converted to a first episode of psychosis (FEP) within the follow-up period. Additionally, 47 FEP and 30 control subjects were included. Using 10 neurophysiological parameters associated with information processing, latent class analyses yielded three classes at baseline. Class membership was related to group status. Within the UHR sample, two classes were found. Transition to psychosis was nominally associated with class membership. Neurophysiological profiles were unstable over time, but associations between specific neurophysiological components at baseline and follow-up were found. We conclude that certain constellations of neurophysiological variables aid in the differentiation between controls and patients in the prodrome and after first psychosis. Copyright © 2014 Society for Psychophysiological Research.

Neurophysiological testing in anorectal disorders

PubMed Central

Remes-Troche, Jose M; Rao, Satish SC

2013-01-01

Neurophysiological tests of anorectal function can provide useful information regarding the integrity of neuronal innervation, as well as neuromuscular function. This information can give insights regarding the pathophysiological mechanisms that lead to several disorders of anorectal function, particularly fecal incontinence, pelvic floor disorders and dyssynergic defecation. Currently, several tests are available for the neurophysiological evaluation of anorectal function. These tests are mostly performed on patients referred to tertiary care centers, either following negative evaluations or when there is lack of response to conventional therapy. Judicious use of these tests can reveal significant and new understanding of the underlying mechanism(s) that could pave the way for better management of these disorders. In addition, these techniques are complementary to other modalities of investigation, such as pelvic floor imaging. The most commonly performed neurophysiological tests, along with their indications and clinical utility are discussed. Several novel techniques are evolving that may reveal new information on brain–gut interactions. PMID:19072383

Dysfunction of Rapid Neural Adaptation in Dyslexia.

PubMed

Perrachione, Tyler K; Del Tufo, Stephanie N; Winter, Rebecca; Murtagh, Jack; Cyr, Abigail; Chang, Patricia; Halverson, Kelly; Ghosh, Satrajit S; Christodoulou, Joanna A; Gabrieli, John D E

2016-12-21

Identification of specific neurophysiological dysfunctions resulting in selective reading difficulty (dyslexia) has remained elusive. In addition to impaired reading development, individuals with dyslexia frequently exhibit behavioral deficits in perceptual adaptation. Here, we assessed neurophysiological adaptation to stimulus repetition in adults and children with dyslexia for a wide variety of stimuli, spoken words, written words, visual objects, and faces. For every stimulus type, individuals with dyslexia exhibited significantly diminished neural adaptation compared to controls in stimulus-specific cortical areas. Better reading skills in adults and children with dyslexia were associated with greater repetition-induced neural adaptation. These results highlight a dysfunction of rapid neural adaptation as a core neurophysiological difference in dyslexia that may underlie impaired reading development. Reduced neurophysiological adaptation may relate to prior reports of reduced behavioral adaptation in dyslexia and may reveal a difference in brain functions that ultimately results in a specific reading impairment. Copyright © 2016 Elsevier Inc. All rights reserved.

Systematic theoretical investigation of the zero-field splitting in Gd(III) complexes: Wave function and density functional approaches

NASA Astrophysics Data System (ADS)

Khan, Shehryar; Kubica-Misztal, Aleksandra; Kruk, Danuta; Kowalewski, Jozef; Odelius, Michael

2015-01-01

The zero-field splitting (ZFS) of the electronic ground state in paramagnetic ions is a sensitive probe of the variations in the electronic and molecular structure with an impact on fields ranging from fundamental physical chemistry to medical applications. A detailed analysis of the ZFS in a series of symmetric Gd(III) complexes is presented in order to establish the applicability and accuracy of computational methods using multiconfigurational complete-active-space self-consistent field wave functions and of density functional theory calculations. The various computational schemes are then applied to larger complexes Gd(III)DOTA(H2O)-, Gd(III)DTPA(H2O)2-, and Gd(III)(H2O)83+ in order to analyze how the theoretical results compare to experimentally derived parameters. In contrast to approximations based on density functional theory, the multiconfigurational methods produce results for the ZFS of Gd(III) complexes on the correct order of magnitude.

Customer needs, expectations, and satisfaction with clinical neurophysiology services in Ireland: a case for tele-neurophysiology development.

PubMed

Fitzsimons, M; Ronan, L; Murphy, K; Browne, G; Connolly, S; McMenamin, J; Delanty, N

2004-01-01

Although equitable access to services should be based on need, geographical location of patients and their clinicians can give rise to inequalities in healthcare delivery. Development of tele-medicine services can improve equity of access. The specialty of Clinical Neurophysiology (CN), currently under-developed in Ireland provides an example of such potential. This study aimed to determine the needs, expectations, and satisfaction of CN customers, namely patients and referring clinicians. The goal was to examine geographical impediments to access that might be addressed by the introduction of tele-neurophysiology. Two customer surveys were conducted: CN referring clinicians and CN patients. Thirty-one North Western Health Board (NWHB) consultant clinicians responded to a postal survey. Distance and delays caused by long waiting lists were felt to deter or make CN referral irrelevant. Ninety-seven percent believed the lack of a local service negatively impacts on patient management and 93% would welcome the introduction of a tele-neurophysiology service. The geographical location of patient's residence and/or the location of the referring clinician's practice influenced waiting lists for CN. Fifty-eight (105/182) percent of patients living in a region with a CN service compared to 39% (50/128) of those living in a region with no service received an appointment within one month. In addition to the current insufficient CN service capacity in Ireland, these surveys highlighted geographical inequities. Tele-neurophysiology has the potential to speed-up diagnosis, result in more patients being appropriately investigated and be fairer to patients.

Understanding in an instant: neurophysiological evidence for mechanistic language circuits in the brain.

PubMed

Pulvermüller, Friedemann; Shtyrov, Yury; Hauk, Olaf

2009-08-01

How long does it take the human mind to grasp the idea when hearing or reading a sentence? Neurophysiological methods looking directly at the time course of brain activity indexes of comprehension are critical for finding the answer to this question. As the dominant cognitive approaches, models of serial/cascaded and parallel processing, make conflicting predictions on the time course of psycholinguistic information access, they can be tested using neurophysiological brain activation recorded in MEG and EEG experiments. Seriality and cascading of lexical, semantic and syntactic processes receives support from late (latency approximately 1/2s) sequential neurophysiological responses, especially N400 and P600. However, parallelism is substantiated by early near-simultaneous brain indexes of a range of psycholinguistic processes, up to the level of semantic access and context integration, emerging already 100-250ms after critical stimulus information is present. Crucially, however, there are reliable latency differences of 20-50ms between early cortical area activations reflecting lexical, semantic and syntactic processes, which are left unexplained by current serial and parallel brain models of language. We here offer a mechanistic model grounded in cortical nerve cell circuits that builds upon neuroanatomical and neurophysiological knowledge and explains both near-simultaneous activations and fine-grained delays. A key concept is that of discrete distributed cortical circuits with specific inter-area topographies. The full activation, or ignition, of specifically distributed binding circuits explains the near-simultaneity of early neurophysiological indexes of lexical, syntactic and semantic processing. Activity spreading within circuits determined by between-area conduction delays accounts for comprehension-related regional activation differences in the millisecond range.

Type III Cells in Anterior Taste Fields Are More Immunohistochemically Diverse Than Those of Posterior Taste Fields in Mice.

PubMed

Wilson, Courtney E; Finger, Thomas E; Kinnamon, Sue C

2017-10-31

Activation of Type III cells in mammalian taste buds is implicated in the transduction of acids (sour) and salty stimuli. Several lines of evidence suggest that function of Type III cells in the anterior taste fields may differ from that of Type III cells in posterior taste fields. Underlying anatomy to support this observation is, however, scant. Most existing immunohistochemical data characterizing this cell type focus on circumvallate taste buds in the posterior tongue. Equivalent data from anterior taste fields-fungiform papillae and soft palate-are lacking. Here, we compare Type III cells in four taste fields: fungiform, soft palate, circumvallate, and foliate in terms of reactivity to four canonical markers of Type III cells: polycystic kidney disease 2-like 1 (PKD2L1), synaptosomal associated protein 25 (SNAP25), serotonin (5-HT), and glutamate decarboxylase 67 (GAD67). Our findings indicate that while PKD2L1, 5-HT, and SNAP25 are highly coincident in posterior taste fields, they diverge in anterior taste fields. In particular, a subset of taste cells expresses PKD2L1 without the synaptic markers, and a subset of SNAP25 cells lacks expression of PKD2L1. In posterior taste fields, GAD67-positive cells are a subset of PKD2L1 expressing taste cells, but anterior taste fields also contain a significant population of GAD67-only expressing cells. These differences in expression patterns may underlie the observed functional differences between anterior and posterior taste fields. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The impact of natural aging on computational and neural indices of perceptual decision making: A review.

PubMed

Dully, Jessica; McGovern, David P; O'Connell, Redmond G

2018-02-10

It is well established that natural aging negatively impacts on a wide variety of cognitive functions and research has sought to identify core neural mechanisms that may account for these disparate changes. A central feature of any cognitive task is the requirement to translate sensory information into an appropriate action - a process commonly known as perceptual decision making. While computational, psychophysical, and neurophysiological research has made substantial progress in establishing the key computations and neural mechanisms underpinning decision making, it is only relatively recently that this knowledge has begun to be applied to research on aging. The purpose of this review is to provide an overview of this work which is beginning to offer new insights into the core psychological processes that mediate age-related cognitive decline in adults aged 65 years and over. Mathematical modelling studies have consistently reported that older adults display longer non-decisional processing times and implement more conservative decision policies than their younger counterparts. However, there are limits on what we can learn from behavioural modeling alone and neurophysiological analyses can play an essential role in empirically validating model predictions and in pinpointing the precise neural mechanisms that are impacted by aging. Although few studies to date have explicitly examined correspondences between computational models and neural data with respect to cognitive aging, neurophysiological studies have already highlighted age-related changes at multiple levels of the sensorimotor hierarchy that are likely to be consequential for decision making behaviour. Here, we provide an overview of this literature and suggest some future directions for the field. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Developments in Neuropsychological and Neurophysiological Assessment: An Overview of Progress and Products of the JWGD3 (Joint Working Group on Drug Dependent Degradation) Level I Neuropsychology Task Area Group

DTIC Science & Technology

1986-01-01

995AB.081 IDA303502 11. TITLE (Indclude Security Classafication) Developments in Neuropsychological and Neurophysiological Assessment: An overview of...progress and products of the JWGD3 Level I Neuropsychology Task Area Group 12. PERSONAL AU1TOR(S) Reeves, D.L.; Taube, S.L. 13a. TYPE OF REPORT I13b...Phone: (301) 588-0058 7 Developments in Neuropsychological and Neurophysiological Assessment An Overview of Progress and Products of the JWGD3 Level I

Intraoperative monitoring for intracranial aneurysms: the Michigan experience.

PubMed

Sahaya, Kinshuk; Pandey, Aditya S; Thompson, Byron G; Bush, Brian R; Minecan, Daniela N

2014-12-01

Intraoperative neurophysiological monitoring is routinely used during the repair (endovascular or microsurgical) of intracranial aneurysms at major centers. There is a continued need of data sets from institutions with dedicated intraoperative neurophysiological monitoring services to further define the predictive factors of postoperative neurological deficits. We retrospectively reviewed and analyzed our database of all patients who underwent repair of intracranial aneurysms (endovascular or microsurgical). A total of 406 patients underwent 470 procedures. The changes were noted during monitoring in 3.83% of the cases. Most of the changes were first detected in somatosensory evoked potential (88.89%) followed by brainstem auditory evoked potential (16.67%). Changes were completely reversible in 44.44%, only partly reversible in 22.22%, and irreversible in 33.33% of cases. Intraoperative neurophysiological monitoring changes demonstrated high sensitivity, specificity, and negative predictive value for postoperative neurological deficits. The association between intraoperative neurophysiological monitoring changes and Glasgow outcome scale was significant for reversible changes compared against irreversible and partly reversible changes. Presence of any intraoperative neurophysiological monitoring modality change during repair of intracranial aneurysm may suggest a higher risk for postoperative neurological deficits. Reversibility of the changes is a favorable marker, whereas irreversible changes are predictive of postoperative neurological deficits with deterioration of Glasgow outcome scale on a longer follow-up.

A neurophysiological study of facial numbness in multiple sclerosis: Integration with clinical data and imaging findings.

PubMed

Koutsis, Georgios; Kokotis, Panagiotis; Papagianni, Aikaterini E; Evangelopoulos, Maria-Eleftheria; Kilidireas, Constantinos; Karandreas, Nikolaos

2016-09-01

To integrate neurophysiological findings with clinical and imaging data in a consecutive series of multiple sclerosis (MS) patients developing facial numbness during the course of an MS attack. Nine consecutive patients with MS and recent-onset facial numbness were studied clinically, imaged with routine MRI, and assessed neurophysiologically with trigeminal somatosensory evoked potential (TSEP), blink reflex (BR), masseter reflex (MR), facial nerve conduction, facial muscle and masseter EMG studies. All patients had unilateral facial hypoesthesia on examination and lesions in the ipsilateral pontine tegmentum on MRI. All patients had abnormal TSEPs upon stimulation of the affected side, excepting one that was tested following remission of numbness. BR was the second most sensitive neurophysiological method with 6/9 examinations exhibiting an abnormal R1 component. The MR was abnormal in 3/6 patients, always on the affected side. Facial conduction and EMG studies were normal in all patients but one. Facial numbness was always related to abnormal TSEPs. A concomitant R1 abnormality on BR allowed localization of the responsible pontine lesion, which closely corresponded with MRI findings. We conclude that neurophysiological assessment of MS patients with facial numbness is a sensitive tool, which complements MRI, and can improve lesion localization. Copyright © 2016 Elsevier B.V. All rights reserved.

Pain processing in atypical Parkinsonisms and Parkinson disease: A comparative neurophysiological study.

PubMed

Avenali, Micol; Tassorelli, Cristina; De Icco, Roberto; Perrotta, Armando; Serrao, Mariano; Fresia, Mauro; Pacchetti, Claudio; Sandrini, Giorgio

2017-10-01

Pain is a frequent non-motor feature in Parkinsonism but mechanistic data on the alteration of pain processing are insufficient to understand the possible causes and to define specifically-targeted treatments. we investigated spinal nociception through the neurophysiological measure of the threshold (TR) of nociceptive withdrawal reflex (NWR) and its temporal summation threshold (TST) comparatively in 12 Progressive Supranuclear Palsy (PSP) subjects, 11 Multiple System Atrophy (MSA) patients, 15 Parkinson's disease (PD) subjects and 24 healthy controls (HC). We also investigated the modulatory effect of L-Dopa in these three parkinsonian groups. We found a significant reduction in the TR of NWR and in the TST of NWR in PSP, MSA and PD patients compared with HC. L-Dopa induced an increase in the TR of NWR in the PSP group while TST of NWR increased in both PSP and PD. Our neurophysiological findings identify a facilitation of nociceptive processing in PSP that is broadly similar to that observed in MSA and PD. Specific peculiarities have emerged for PSP. Our data advance the knowledge of the neurophysiology of nociception in the advanced phases of parkinsonian syndromes and on the role of dopaminergic pathways in the control on pain processing. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Sensed presence and mystical experiences are predicted by suggestibility, not by the application of transcranial weak complex magnetic fields.

PubMed

Granqvist, Pehr; Fredrikson, Mats; Unge, Patrik; Hagenfeldt, Andrea; Valind, Sven; Larhammar, Dan; Larsson, Marcus

2005-04-29

Transcranial magnetic stimulation (TMS) with weak (micro Tesla) complex waveform fields have been claimed to evoke the sensed presence of a sentient being in up to 80% in the general population. These findings have had a questionable neurophysiological foundation as the fields are approximately six orders of magnitude weaker than ordinary TMS fields. Also, no independent replication has been reported. To replicate and extend previous findings, we performed a double-blind experiment (N=89), with a sham-field control group. Personality characteristics indicating suggestibility (absorption, signs of abnormal temporal lobe activity, and a "new age"-lifestyle orientation) were used as predictors. Sensed presence, mystical, and other somatosensory experiences previously reported from the magnetic field stimulation were outcome measures. We found no evidence for any effects of the magnetic fields, neither in the entire group, nor in individuals high in suggestibility. Because the personality characteristics significantly predicted outcomes, suggestibility may account for previously reported effects. Our results strongly question the earlier claims of experiential effects of weak magnetic fields.

Analyzing neural responses with vector fields.

PubMed

Buneo, Christopher A

2011-04-15

Analyzing changes in the shape and scale of single cell response fields is a key component of many neurophysiological studies. Typical analyses of shape change involve correlating firing rates between experimental conditions or "cross-correlating" single cell tuning curves by shifting them with respect to one another and correlating the overlapping data. Such shifting results in a loss of data, making interpretation of the resulting correlation coefficients problematic. The problem is particularly acute for two dimensional response fields, which require shifting along two axes. Here, an alternative method for quantifying response field shape and scale based on correlation of vector field representations is introduced. The merits and limitations of the methods are illustrated using both simulated and experimental data. It is shown that vector correlation provides more information on response field changes than scalar correlation without requiring field shifting and concomitant data loss. An extension of this vector field approach is also demonstrated which can be used to identify the manner in which experimental variables are encoded in studies of neural reference frames. Copyright © 2011 Elsevier B.V. All rights reserved.

Detectability of Granger causality for subsampled continuous-time neurophysiological processes.

PubMed

Barnett, Lionel; Seth, Anil K

2017-01-01

Granger causality is well established within the neurosciences for inference of directed functional connectivity from neurophysiological data. These data usually consist of time series which subsample a continuous-time biophysiological process. While it is well known that subsampling can lead to imputation of spurious causal connections where none exist, less is known about the effects of subsampling on the ability to reliably detect causal connections which do exist. We present a theoretical analysis of the effects of subsampling on Granger-causal inference. Neurophysiological processes typically feature signal propagation delays on multiple time scales; accordingly, we base our analysis on a distributed-lag, continuous-time stochastic model, and consider Granger causality in continuous time at finite prediction horizons. Via exact analytical solutions, we identify relationships among sampling frequency, underlying causal time scales and detectability of causalities. We reveal complex interactions between the time scale(s) of neural signal propagation and sampling frequency. We demonstrate that detectability decays exponentially as the sample time interval increases beyond causal delay times, identify detectability "black spots" and "sweet spots", and show that downsampling may potentially improve detectability. We also demonstrate that the invariance of Granger causality under causal, invertible filtering fails at finite prediction horizons, with particular implications for inference of Granger causality from fMRI data. Our analysis emphasises that sampling rates for causal analysis of neurophysiological time series should be informed by domain-specific time scales, and that state-space modelling should be preferred to purely autoregressive modelling. On the basis of a very general model that captures the structure of neurophysiological processes, we are able to help identify confounds, and offer practical insights, for successful detection of causal connectivity from neurophysiological recordings. Copyright © 2016 Elsevier B.V. All rights reserved.

Neural autoantibodies and neurophysiologic abnormalities in patients exposed to molds in water-damaged buildings.

PubMed

Campbell, Andrew W; Thrasher, Jack D; Madison, Roberta A; Vojdani, Aristo; Gray, Michael R; Johnson, Al

2003-08-01

Adverse health effects of fungal bioaerosols on occupants of water-damaged homes and other buildings have been reported. Recently, it has been suggested that mold exposure causes neurological injury. The authors investigated neurological antibodies and neurophysiological abnormalities in patients exposed to molds at home who developed symptoms of peripheral neuropathy (i.e., numbness, tingling, tremors, and muscle weakness in the extremities). Serum samples were collected and analyzed with the enzyme-linked immunosorbent assay (ELISA) technique for antibodies to myelin basic protein, myelin-associated glycoprotein, ganglioside GM1, sulfatide, myelin oligodendrocyte glycoprotein, alpha-B-crystallin, chondroitin sulfate, tubulin, and neurofilament. Antibodies to molds and mycotoxins were also determined with ELISA, as reported previously. Neurophysiologic evaluations for latency, amplitude, and velocity were performed on 4 motor nerves (median, ulnar, peroneal, and tibial), and for latency and amplitude on 3 sensory nerves (median, ulnar, and sural). Patients with documented, measured exposure to molds had elevated titers of antibodies (immunoglobulin [Ig]A, IgM, and IgG) to neural-specific antigens. Nerve conduction studies revealed 4 patient groupings: (1) mixed sensory-motor polyneuropathy (n = 55, abnormal), (2) motor neuropathy (n = 17, abnormal), (3) sensory neuropathy (n = 27, abnormal), and (4) those with symptoms but no neurophysiological abnormalities (n = 20, normal controls). All groups showed significantly increased autoantibody titers for all isotypes (IgA, IgM, and IgG) of antibodies to neural antigens when compared with 500 healthy controls. Groups 1 through 3 also exhibited abnormal neurophysiologic findings. The authors concluded that exposure to molds in water-damaged buildings increased the risk for development of neural autoantibodies, peripheral neuropathy, and neurophysiologic abnormalities in exposed individuals.

On spatial attention and its field size on the repulsion effect

PubMed Central

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

2018-01-01

We investigated the attentional repulsion effect—stimuli appear displaced further away from attended locations—in three experiments: one with exogenous (involuntary) attention, and two with endogenous (voluntary) attention with different attention-field sizes. It has been proposed that differences in attention-field size can account for qualitative differences in neural responses elicited by attended stimuli. We used psychophysical comparative judgments and manipulated either exogenous attention via peripheral cues or endogenous attention via central cues and a demanding rapid serial visual presentation task. We manipulated the attention field size of endogenous attention by presenting streams of letters at two specific locations or at two of many possible locations during each block. We found a robust attentional repulsion effect in all three experiments: with endogenous and exogenous attention and with both attention-field sizes. These findings advance our understanding of the influence of spatial attention on the perception of visual space and help relate this repulsion effect to possible neurophysiological correlates.

Bilateral frontal activation associated with cutaneous stimulation of elixir field: an FMRI study.

PubMed

Chan, Agnes S; Cheung, Mei-Chun; Chan, Yu Leung; Yeung, David K W; Lam, Wan

2006-01-01

Elixir Field, or Dan Tian, is the area where energy is stored and nourished in the body according to traditional Chinese medicine (TCM). Although Dan Tian stimulation is a major concept in Qigong healing and has been practiced for thousands of years, and while there are some recent empirical evidence of its effect, its neurophysiological basis remains unknown. We used functional magnetic resonance imaging (fMRI) to study brain activations associated with external stimulation of the lower Elixir Field in ten normal subjects, and compared the results with the stimulation of their right hands. While right-hand stimulation resulted in left postcentral gyrus activation, stimulation of the lower Elixir Field resulted in bilateral activations including the medial and superior frontal gyrus, middle and superior temporal gyrus, thalamus, insula, and cingulate gyrus. These findings suggest that stimulation of the Elixir Field is not only associated with activation of the sensory motor cortex but also with cortical regions that mediate planning, attention, and memory.

Unusual Enhancement of Magnetization by Pressure in the Antiferro-Quadrupole-Ordered Phase in CeB6

NASA Astrophysics Data System (ADS)

Ikeda, Suguru; Sera, Masafumi; Hane, Shingo; Uwatoko, Yoshiya; Kosaka, Masashi; Kunii, Satoru

2007-06-01

The effect of pressure on CeB6 was investigated by the measurement of the magnetization (M) under pressure, and we obtained the following results. The effect of pressure on M in phase I is very small. By applying pressure, TQ is enhanced, but TN and the critical field from the antiferromagnetic (AFM) phase III to the antiferro-quadrupole (AFQ) phase II (HcIII--II) are suppressed, as previously reported. The magnetization curve in phase III shows the characteristic shoulder at H˜ HcIII--II/2 at ambient pressure. This shoulder becomes much more pronounced by applying pressure. Both HcIII--II and the magnetic field, where a shoulder is seen in the magnetization curve in phase III, are largely suppressed by pressure. In phase II, the M-T curve at a low magnetic field exhibits an unusual concave temperature dependence below TQ down to TN. Thus, we found that the lower the magnetic field, the larger the enhancement of M in both phases III and II. To clarify the origin of the unusual pressure effect of M, we performed a mean-field calculation for the 4-sublattice model using the experimental results of dTQ/dP>0 and dTN/dP<0 and assuming the positive pressure dependence of the Txyz-antiferro-octupole (AFO) interaction. The characteristic features of the pressure effect of M obtained by the experiments could be reproduced well by the mean-field calculation. We found that the origin of the characteristic effect of pressure on CeB6 is the change in the subtle balance between the AFM interaction and the magnetic field-induced-effective FM interaction induced by the coexistence of the Oxy-AFQ and Txyz-AFO interactions under pressure.

Measurement model as a means for studying the process of emotion origination

NASA Astrophysics Data System (ADS)

Taymanov, R.; Baksheeva, Iu; Sapozhnikova, K.; Chunovkina, A.

2016-11-01

In the last edition of the International Vocabulary of Metrology the concept “measurement” was spread outside the field of physical quantities. This fact makes it relevant to analyze the experience of developing the models of multidimensional quantity measurements. The model of measurements of expected emotions caused by musical and other acoustic impacts, is considered. The model relies upon a hypothesis of a nonlinear conversion of acoustic signals to a neurophysiological reaction giving rise to emotion. Methods for checking this hypothesis as well as experimental results are given.

Neurophysiology and neural engineering: a review.

PubMed

Prochazka, Arthur

2017-08-01

Neurophysiology is the branch of physiology concerned with understanding the function of neural systems. Neural engineering (also known as neuroengineering) is a discipline within biomedical engineering that uses engineering techniques to understand, repair, replace, enhance, or otherwise exploit the properties and functions of neural systems. In most cases neural engineering involves the development of an interface between electronic devices and living neural tissue. This review describes the origins of neural engineering, the explosive development of methods and devices commencing in the late 1950s, and the present-day devices that have resulted. The barriers to interfacing electronic devices with living neural tissues are many and varied, and consequently there have been numerous stops and starts along the way. Representative examples are discussed. None of this could have happened without a basic understanding of the relevant neurophysiology. I also consider examples of how neural engineering is repaying the debt to basic neurophysiology with new knowledge and insight. Copyright © 2017 the American Physiological Society.

Inferring multi-scale neural mechanisms with brain network modelling

PubMed Central

Schirner, Michael; McIntosh, Anthony Randal; Jirsa, Viktor; Deco, Gustavo

2018-01-01

The neurophysiological processes underlying non-invasive brain activity measurements are incompletely understood. Here, we developed a connectome-based brain network model that integrates individual structural and functional data with neural population dynamics to support multi-scale neurophysiological inference. Simulated populations were linked by structural connectivity and, as a novelty, driven by electroencephalography (EEG) source activity. Simulations not only predicted subjects' individual resting-state functional magnetic resonance imaging (fMRI) time series and spatial network topologies over 20 minutes of activity, but more importantly, they also revealed precise neurophysiological mechanisms that underlie and link six empirical observations from different scales and modalities: (1) resting-state fMRI oscillations, (2) functional connectivity networks, (3) excitation-inhibition balance, (4, 5) inverse relationships between α-rhythms, spike-firing and fMRI on short and long time scales, and (6) fMRI power-law scaling. These findings underscore the potential of this new modelling framework for general inference and integration of neurophysiological knowledge to complement empirical studies. PMID:29308767

CLINICAL AUTONOMIC NEUROPHYSIOLOGY AND THE MALE SEXUAL RESPONSE: AN OVERVIEW

PubMed Central

Yang, Claire C.; Jiang, Xiaogang

2009-01-01

Introduction Clinical neurophysiology is the study of the human nervous system through the recording of bioelectrical activity. In the realm of male sexual functioning, this includes using electrophysiologic techniques to study the nerves subserving erection, emission, ejaculation, and orgasm. Aim To introduce the reader to the principles of clinical neurophysiology as they relate to the male sexual response, particularly erection. Methods We review the pertinent autonomic neuroanatomy and neurophysiology of reflexes relevant to the male sexual response, as well as summarize the genital electrodiagnostic tests that are being used to interrogate the autonomic innervation pertinent to male sexual functioning. Conclusions The male sexual response is a coordinated series of interactions between the somatic and the autonomic nervous systems. Measurement of the autonomically mediated portions of the sexual reflexes is of great clinical interest, particularly in relation to erection. Advances in clinical electrodiagnostics now allow for consistent recording of evoked and spontaneous intra-penile electrical activity. However, before broad and widespread use of these techniques is possible, more investigations are needed. PMID:19267845

The neurophysiology of pain perception and hypnotic analgesia: implications for clinical practice.

PubMed

Jensen, Mark P

2008-10-01

Although there remains much to be learned, a great deal is now known about the neurophysiological processes involved in the experience of pain. Research confirms that there is no single focal "center" in the brain responsible for the experience of pain. Rather, pain is the end product of a number of integrated networks that involve activity at multiple cortical and subcortical sites. Our current knowledge about the neurophysiological mechanisms of pain has important implications for understanding the mechanisms underlying the effects of hypnotic analgesia treatments, as well as for improving clinical practice. This article is written for the clinician who uses hypnotic interventions for pain management. It begins with an overview of what is known about the neurophysiological basis of pain and hypnotic analgesia, and then discusses how clinicians can use this knowledge for (1) organizing the types of suggestions that can be used when providing hypnotic treatment, and (2) maximizing the efficacy of hypnotic interventions in clients presenting with pain problems.

Biological markers for anxiety disorders, OCD and PTSD: A consensus statement. Part II: Neurochemistry, neurophysiology and neurocognition

PubMed Central

Bandelow, Borwin; Baldwin, David; Abelli, Marianna; Bolea-Alamanac, Blanca; Bourin, Michel; Chamberlain, Samuel R.; Cinosi, Eduardo; Davies, Simon; Domschke, Katharina; Fineberg, Naomi; Grünblatt, Edna; Jarema, Marek; Kim, Yong-Ku; Maron, Eduard; Masdrakis, Vasileios; Mikova, Olya; Nutt, David; Pallanti, Stefano; Pini, Stefano; Ströhle, Andreas; Thibaut, Florence; Vaghix, Matilde M.; Won, Eunsoo; Wedekind, Dirk; Wichniak, Adam; Woolley, Jade; Zwanzger, Peter; Riederer, Peter

2017-01-01

Objective Biomarkers are defined as anatomical, biochemical or physiological traits that are specific to certain disorders or syndromes. The objective of this paper is to summarise the current knowledge of biomarkers for anxiety disorders, obsessive-compulsive disorder (OCD) and posttraumatic stress disorder (PTSD). Methods Findings in biomarker research were reviewed by a task force of international experts in the field, consisting of members of the World Federation of Societies for Biological Psychiatry Task Force on Biological Markers and of the European College of Neuropsychopharmacology Anxiety Disorders Research Network. Results The present article (Part II) summarises findings on potential biomarkers in neurochemistry (neurotransmitters such as serotonin, norepinephrine, dopamine or GABA, neuropeptides such as cholecystokinin, neurokinins, atrial natriuretic peptide, or oxytocin, the HPA axis, neurotrophic factors such as NGF and BDNF, immunology and CO2 hypersensitivity), neurophysiology (EEG, heart rate variability) and neurocognition. The accompanying paper (Part I) focuses on neuroimaging and genetics. Conclusions Although at present, none of the putative biomarkers is sufficient and specific as a diagnostic tool, an abundance of high quality research has accumulated that should improve our understanding of the neurobiological causes of anxiety disorders, OCD and PTSD. PMID:27419272

Social neuroscience and theory of mind.

PubMed

Westby, Carol E

2014-01-01

The role of theory of mind (ToM) in autism spectrum disorders and other communication impairments has been an active area of research in the last 30 years. Advances in neuroimaging in the last 10 years have led to the rise of the field of social neuroscience, which has markedly increased the understanding of the neurophysiological/neuroanatomical and neurochemical nature of ToM functioning and deficits in typically developing individuals and in children and adults with a variety of social and communication impairments. The goal of this paper is to (a) describe the current concepts of ToM based on neuroscience research, and (b) present a framework for the dimensions of ToM that have been identified, which can be used to guide assessment and intervention for persons with deficits in ToM that affect social interactions. This article presents neuroscience research that has documented the neurophysiological/neuroanatomical bases for cognitive and affective ToM and interpersonal and intrapersonal ToM as well as neurochemical and epigenetic influences on ToM. This information provides an important framework for assessing ToM deficits in persons with social and communication impairments and developing interventions that target the specific dimensions of ToM deficits. © 2014 S. Karger AG, Basel.

Nonretinotopic visual processing in the brain.

PubMed

Melcher, David; Morrone, Maria Concetta

2015-01-01

A basic principle in visual neuroscience is the retinotopic organization of neural receptive fields. Here, we review behavioral, neurophysiological, and neuroimaging evidence for nonretinotopic processing of visual stimuli. A number of behavioral studies have shown perception depending on object or external-space coordinate systems, in addition to retinal coordinates. Both single-cell neurophysiology and neuroimaging have provided evidence for the modulation of neural firing by gaze position and processing of visual information based on craniotopic or spatiotopic coordinates. Transient remapping of the spatial and temporal properties of neurons contingent on saccadic eye movements has been demonstrated in visual cortex, as well as frontal and parietal areas involved in saliency/priority maps, and is a good candidate to mediate some of the spatial invariance demonstrated by perception. Recent studies suggest that spatiotopic selectivity depends on a low spatial resolution system of maps that operates over a longer time frame than retinotopic processing and is strongly modulated by high-level cognitive factors such as attention. The interaction of an initial and rapid retinotopic processing stage, tied to new fixations, and a longer lasting but less precise nonretinotopic level of visual representation could underlie the perception of both a detailed and a stable visual world across saccadic eye movements.

Dosimetric comparison of three intensity-modulated radiation therapies for left breast cancer after breast-conserving surgery.

PubMed

Zhang, Huai-Wen; Hu, Bo; Xie, Chen; Wang, Yun-Lai

2018-05-01

This study aimed to evaluate dosimetric differences of intensity-modulated radiation therapy (IMRT) in target and normal tissues after breast-conserving surgery. IMRT five-field plan I, IMRT six-field plan II, and field-in-field-direct machine parameter optimization-IMRT plan III were designed for each of the 50 patients. One-way analysis of variance was performed to compare differences, and P < 0.05 was considered statistically significant. Homogeneity index of plan III is lower than those of plans I and II. No difference was identified in conformity index of targets. Plan I exhibited difference in mean dose (D mean ) for the heart (P < 0.05). Plan I featured smaller irradiation dose volumes in V 5 , V 20 (P < 0.05) of the left lung than II. Plan I exhibited significantly higher V 5 in the right lung than plans II and III (P < 0.05). Under plan I, irradiation dose at V 5 in the right breast is higher than that in plans II and III. Patients in plan III presented less total monitor unit and total treatment time than those in plans I and II (P < 0.05). IMRT six-field plans II, and field-in-field-direct machine parameter optimization-IMRT plans III can reduce doses and volumes to the lungs and heart better while maintaining satisfying conformity index and homogeneity index of target. Nevertheless, plan II neglects target movements caused by respiration. In the same manner, plan III can substantially reduce MU and shorten patient treatment time. Therefore, plan III, which considers target movement caused by respiration, is a more practical radiation mode. © 2018 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

A removable silicone elastomer seal reduces granulation tissue growth and maintains the sterility of recording chambers for primate neurophysiology

PubMed Central

Spitler, Kevin M.; Gothard, Katalin M.

2008-01-01

The maintenance of the sterility of craniotomies for serial acute neurophysiological recordings is exacting and time consuming yet is vital to the health of valuable experimental animals. We have developed a method to seal the craniotomy with surgical grade silicone elastomer (Silastic®) in a hermetically sealed chamber. Under these conditions the tissues in the craniotomy and the inside surface of the chamber remain unpopulated by bacteria. The silicone elastomer sealant retarded the growth of granulation tissue on the dura and reduced the procedures required to maintain ideal conditions for neurophysiological recordings. PMID:18241928

[Neurophysiology of pruritus].

PubMed

Raap, U; Ikoma, A; Kapp, A

2006-05-01

Neurophysiologic studies indicate that pruritus is a distinct sensation with its own neuronal pathways in the peripheral and central nervous system which are different from that of pain. Pruritus is a very disturbing sensation and most common skin-related symptom. Histamine was long considered to be the only mediator of pruritus. However, it has become evident that - besides histamine - a variety of neuromediators such as neurotrophins and neuropeptides as well as their receptors play an important role in pruritus. Neuromediators are produced by mast cells, keratinocytes and eosinophil granulocytes which are in close contact to sensory nerves. The discovery of these neurophysiological interactions opens new and promising therapeutic options for the treatment of pruritus.

Hybrid organic-inorganic connectivity of NdIII(pyrazine-N,N'-dioxide)[CoIII(CN)6]3- coordination chains for creating near-infrared emissive Nd(iii) showing field-induced slow magnetic relaxation.

PubMed

Chorazy, Szymon; Charytanowicz, Tomasz; Wang, Junhao; Ohkoshi, Shin-Ichi; Sieklucka, Barbara

2018-05-29

A near-infrared emissive and magnetically anisotropic Nd(iii) complex is formed within a hybrid organic-inorganic {[NdIII(pzdo)(H2O)4][CoIII(CN)6]}·0.5(pzdo)·4H2O (1) (pzdo = pyrazine-N,N'-dioxide) ladder chain built of coexisting Nd-pzdo-Nd and Nd-NC-Co molecular bridges. 1 reveals two NdIII-centered properties, a field-induced slow magnetic relaxation of a single-ion origin with a thermal energy barrier of ΔE/kB = 51(2) K at Hdc = 1 kOe, and a near-infrared fluorescence sensitized by organic and inorganic linkers.

Backwards and Forwards: Behavioral and Neurophysiological Investigations into Dependency Processing

ERIC Educational Resources Information Center

Witzel, Jeffrey D.

2010-01-01

This dissertation examines the processing of sentences involving long-distance linguistic dependencies, or sentences containing elements that must be linked across intervening words and phrases. Specifically, both behavioral (self-paced reading and eye tracking) and neurophysiological (electroencephalography) methods were used (a) to evaluate the…

Science Education: An Experiment in Facilitating the Learning of Neurophysiology.

ERIC Educational Resources Information Center

Levitan, Herbert

1981-01-01

Summarizes the experiences of a zoology professor attempting to construct a student-centered course in neurophysiology. Various aspects of the organization and conduct of the course are described, including the beginning experience, topics of interest, lecture, laboratory, computer simulation, examinations, student lectures. Evaluation of the…

Neurophysiological Facilitation of Eating Skills in Children with Severe Handicaps.

ERIC Educational Resources Information Center

Sobsey, Richard; Orelove, Fred P.

1984-01-01

Effectiveness of neurophysiological facilitation procedures (exteroceptive and proprioceptive stimulation) was evaluated on lip closure, rotary chewing, and food spilling from the mouth of four severely disabled children (3-12 years old). Some improvements in eating skills were found in each student following facilitation procedures. (CL)

Biomechanical correlates of symptomatic and asymptomatic neurophysiological impairment in high school football.

PubMed

Breedlove, Evan L; Robinson, Meghan; Talavage, Thomas M; Morigaki, Katherine E; Yoruk, Umit; O'Keefe, Kyle; King, Jeff; Leverenz, Larry J; Gilger, Jeffrey W; Nauman, Eric A

2012-04-30

Concussion is a growing public health issue in the United States, and chronic traumatic encephalopathy (CTE) is the chief long-term concern linked to repeated concussions. Recently, attention has shifted toward subconcussive blows and the role they may play in the development of CTE. We recruited a cohort of high school football players for two seasons of observation. Acceleration sensors were placed in the helmets, and all contact activity was monitored. Pre-season computer-based neuropsychological tests and functional magnetic resonance imaging (fMRI) tests were also obtained in order to assess cognitive and neurophysiological health. In-season follow-up scans were then obtained both from individuals who had sustained a clinically-diagnosed concussion and those who had not. These changes were then related through stepwise regression to history of blows recorded throughout the football season up to the date of the scan. In addition to those subjects who had sustained a concussion, a substantial portion of our cohort who did not sustain concussions showed significant neurophysiological changes. Stepwise regression indicated significant relationships between the number of blows sustained by a subject and the ensuing neurophysiological change. Our findings reinforce the hypothesis that the effects of repetitive blows to the head are cumulative and that repeated exposure to subconcussive blows is connected to pathologically altered neurophysiology. Copyright © 2012 Elsevier Ltd. All rights reserved.

Influence of neurophysiological hippotherapy on the transference of the centre of gravity among children with cerebral palsy.

PubMed

Maćków, Anna; Małachowska-Sobieska, Monika; Demczuk-Włodarczyk, Ewa; Sidorowska, Marta; Szklarska, Alicja; Lipowicz, Anna

2014-01-01

The aim of the study was to present the influence of neurophysiological hippotherapy on the transference of the centre of gravity (COG) among children with cerebral palsy (CP). The study involved 19 children aged 4-13 years suffering from CP who demonstrated an asymmetric (A/P) model of compensation. Body balance was studied with the Cosmogamma Balance Platform. An examination on this platform was performed before and after a session of neurophysiological hippotherapy. In order to compare the correlations and differences between the examinations, the results were analysed using Student's T-test for dependent samples at p ≤ 0.05 as the level of statistical significance and descriptive statistics were calculated. The mean value of the body's centre of gravity in the frontal plane (COG X) was 18.33 (mm) during the first examination, changing by 21.84 (mm) after neurophysiological hippotherapy towards deloading of the antigravity lower limb (p ≤ 0.0001). The other stabilographic parameters increased; however, only the change in average speed of antero - posterior COG oscillation was statistically significant (p = 0.0354). 1. One session of neurophysiological hippotherapy induced statistically significant changes in the position of the centre of gravity in the body in the frontal plane and the average speed of COG oscillation in the sagittal plane among CP children demonstrating an asymmetric model of compensation (A/P).

Neurophysiological mechanisms of cortical plasticity impairments in schizophrenia and modulation by the NMDA receptor agonist D-serine

PubMed Central

Kantrowitz, Joshua T.; Epstein, Michael L.; Beggel, Odeta; Rohrig, Stephanie; Lehrfeld, Jonathan M.; Revheim, Nadine; Lehrfeld, Nayla P.; Reep, Jacob; Parker, Emily; Silipo, Gail; Ahissar, Merav; Javitt, Daniel C.

2016-01-01

Schizophrenia is associated with deficits in cortical plasticity that affect sensory brain regions and lead to impaired cognitive performance. Here we examined underlying neural mechanisms of auditory plasticity deficits using combined behavioural and neurophysiological assessment, along with neuropharmacological manipulation targeted at the N-methyl-D-aspartate type glutamate receptor (NMDAR). Cortical plasticity was assessed in a cohort of 40 schizophrenia/schizoaffective patients relative to 42 healthy control subjects using a fixed reference tone auditory plasticity task. In a second cohort (n = 21 schizophrenia/schizoaffective patients, n = 13 healthy controls), event-related potential and event-related time–frequency measures of auditory dysfunction were assessed during administration of the NMDAR agonist d-serine. Mismatch negativity was used as a functional read-out of auditory-level function. Clinical trials registration numbers were NCT01474395/NCT02156908. Schizophrenia/schizoaffective patients showed significantly reduced auditory plasticity versus healthy controls (P = 0.001) that correlated with measures of cognitive, occupational and social dysfunction. In event-related potential/time-frequency analyses, patients showed highly significant reductions in sensory N1 that reflected underlying impairments in θ responses (P < 0.001), along with reduced θ and β-power modulation during retention and motor-preparation intervals. Repeated administration of d-serine led to intercorrelated improvements in (i) auditory plasticity (P < 0.001); (ii) θ-frequency response (P < 0.05); and (iii) mismatch negativity generation to trained versus untrained tones (P = 0.02). Schizophrenia/schizoaffective patients show highly significant deficits in auditory plasticity that contribute to cognitive, occupational and social dysfunction. d-serine studies suggest first that NMDAR dysfunction may contribute to underlying cortical plasticity deficits and, second, that repeated NMDAR agonist administration may enhance cortical plasticity in schizophrenia. PMID:27913408

Pain assessment by continuous EEG: association between subjective perception of tonic pain and peak frequency of alpha oscillations during stimulation and at rest.

PubMed

Nir, Rony-Reuven; Sinai, Alon; Raz, Einat; Sprecher, Elliot; Yarnitsky, David

2010-07-16

Recordings of neurophysiological brain responses to noxious stimuli have been traditionally based on short stimuli, in the order of milliseconds, which induce distinct event-related potentials (ERPs). However, using such stimuli in the experimental setting is disadvantageous as they are too brief to faithfully simulate clinical pain. We aimed at utilizing continuous EEG to investigate the properties of peak alpha frequency (PAF) as an objective cortical measure associated with subjective perception of tonic pain. Five minute long continuous EEG was recorded in 18 healthy volunteers under: (i) resting-state; (ii) innocuous temperature; and (iii) psychophysically-anchored noxious temperature. Numerical pain scores (NPSs) collected during the application of tonic noxious stimuli were tested for correlation with peak frequencies of alpha power-curves derived from central, temporal and frontal electrodes. NPSs and PAFs remained stable throughout the recording conditions (RM-ANOVAs; Ps>0.51). In the noxious condition, PAFs obtained at the bilateral temporal scalp were correlated with NPSs (Ps<0.001). Moreover, resting-state PAFs recorded at the bilateral temporal scalp were correlated with NPSs reported during the noxious condition (Ps<0.01). These psychophysical-neurophysiological relations attest to the properties of PAF as a novel cortical objective measure of subjective perception of tonic pain. Moreover, resting-state PAFs might hold inherent pain modulation attributes, possibly enabling the prediction of individual responsiveness to prolonged pain. The relevance of PAF to the neural processing of tonic pain may indicate its potential to advance pain research as well as clinical pain characterization. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Consensus-based guidelines for Video EEG monitoring in the pre-surgical evaluation of children with epilepsy in the UK.

PubMed

Pressler, Ronit M; Seri, Stefano; Kane, Nick; Martland, Tim; Goyal, Sushma; Iyer, Anand; Warren, Elliott; Notghi, Lesley; Bill, Peter; Thornton, Rachel; Appleton, Richard; Doyle, Sarah; Rushton, Sarah; Worley, Alan; Boyd, Stewart G

2017-08-01

Paediatric Epilepsy surgery in the UK has recently been centralised in order to improve expertise and quality of service available to children. Video EEG monitoring or telemetry is a highly specialised and a crucial component of the pre-surgical evaluation. Although many Epilepsy Monitoring Units work to certain standards, there is no national or international guideline for paediatric video telemetry. Due to lack of evidence we used a modified Delphi process utilizing the clinical and academic expertise of the clinical neurophysiology sub-specialty group of Children's Epilepsy Surgical Service (CESS) centres in England and Wales. This process consisted of the following stages I: Identification of the consensus working group, II: Identification of key areas for guidelines, III: Consensus practice points and IV: Final review. Statements that gained consensus (median score of either 4 or 5 using a five-point Likerttype scale) were included in the guideline. Two rounds of feedback and amendments were undertaken. The consensus guidelines includes the following topics: referral pathways, neurophysiological equipment standards, standards of recording techniques, with specific emphasis on safety of video EEG monitoring both with and without drug withdrawal, a protocol for testing patient's behaviours, data storage and guidelines for writing factual reports and conclusions. All statements developed received a median score of 5 and were adopted by the group. Using a modified Delphi process we were able to develop universally-accepted video EEG guidelines for the UK CESS. Although these recommendations have been specifically developed for the pre-surgical evaluation of children with epilepsy, it is assumed that most components are transferable to any paediatric video EEG monitoring setting. Copyright © 2017 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Disciplinarity and sport science in Europe: A statistical and sociological study of ECSS conference abstracts.

PubMed

Champely, Stéphane; Fargier, Patrick; Camy, Jean

2017-02-01

Abstracts of European College of Sports Science conferences (1995-2014) are studied. The number of abstracts has been increasing regularly (+90 per year). This rise is in recent years largely due to extra-European countries. The magnitude and accumulation of the different topics of discussion are examined. An operational criterion determines four stages of evolution of a topic: social network, cluster, specialty, and discipline. The scientific production can, therefore, be classified as disciplinary or non-disciplinary. The disciplinary part is more important but has been less dynamic recently. The cognitive content of sport science is then explored through a multidimensional scaling of the topics based on the keywords used in the abstracts. Three areas are visible: social sciences and humanities, sports medicine and physiology, and biomechanics and neurophysiology. According to the field theory of Bourdieu ( 1975 ), three scientific habitus are distinguished. The logic of academic disciplinary excellence is the consequence of the autonomy of this scientific field, its closure, peer-review process, and barriers to entry. The distribution of scientific capital and professional capital is unequal across the three areas. Basically, conservation strategies of academic disciplinary excellence are predicted in biomechanics and neurophysiology, subversion strategies of interdisciplinarity based on professional concerns can appear in the sports medicine and physiology area, and critical strategies of interdisciplinarity based on social utility in social sciences and humanities. Moreover, additional tensions within these areas are depicted. Lastly methods based on co-citations of disciplines and boundary objects are proposed to find tangible patterns of multidisciplinarity confirming these strategies.

High-performance III-V MOSFET with nano-stacked high-k gate dielectric and 3D fin-shaped structure.

PubMed

Chen, Szu-Hung; Liao, Wen-Shiang; Yang, Hsin-Chia; Wang, Shea-Jue; Liaw, Yue-Gie; Wang, Hao; Gu, Haoshuang; Wang, Mu-Chun

2012-08-01

A three-dimensional (3D) fin-shaped field-effect transistor structure based on III-V metal-oxide-semiconductor field-effect transistor (MOSFET) fabrication has been demonstrated using a submicron GaAs fin as the high-mobility channel. The fin-shaped channel has a thickness-to-width ratio (TFin/WFin) equal to 1. The nano-stacked high-k Al2O3 dielectric was adopted as a gate insulator in forming a metal-oxide-semiconductor structure to suppress gate leakage. The 3D III-V MOSFET exhibits outstanding gate controllability and shows a high Ion/Ioff ratio > 105 and a low subthreshold swing of 80 mV/decade. Compared to a conventional Schottky gate metal-semiconductor field-effect transistor or planar III-V MOSFETs, the III-V MOSFET in this work exhibits a significant performance improvement and is promising for future development of high-performance n-channel devices based on III-V materials.

High-performance III-V MOSFET with nano-stacked high-k gate dielectric and 3D fin-shaped structure

PubMed Central

2012-01-01

A three-dimensional (3D) fin-shaped field-effect transistor structure based on III-V metal-oxide-semiconductor field-effect transistor (MOSFET) fabrication has been demonstrated using a submicron GaAs fin as the high-mobility channel. The fin-shaped channel has a thickness-to-width ratio (TFin/WFin) equal to 1. The nano-stacked high-k Al2O3 dielectric was adopted as a gate insulator in forming a metal-oxide-semiconductor structure to suppress gate leakage. The 3D III-V MOSFET exhibits outstanding gate controllability and shows a high Ion/Ioff ratio > 105 and a low subthreshold swing of 80 mV/decade. Compared to a conventional Schottky gate metal–semiconductor field-effect transistor or planar III-V MOSFETs, the III-V MOSFET in this work exhibits a significant performance improvement and is promising for future development of high-performance n-channel devices based on III-V materials. PMID:22853458

[Clinical and neurophysiological aspects of severe forms of autism in children].

PubMed

Simashkova, N V; Iakupova, L P; Bashina, V M

2006-01-01

The aim of the study was to elucidate fundamentals for the phenomenon of universality of childhood autism by comparison of clinical and neurophysiological features of its severest forms--children endogenous autism (CEA) and Rett's syndrome (RS). Each group included 20 patients. Both groups were similar by age-at-disease-onset, clinical appearances during the disease course and dynamics of psychopathological syndromes. The theta-rhythm is common for CEA and RS at the disease stage with marked signs of disease acuity, autism, regress and, therefore, may be regarded as a marker of severity and development delay. The universality of autism phenomenon in its severe forms was confirmed both at the clinical and neurophysiological levels.

Fabrication of neurophysiological monitoring systems

NASA Technical Reports Server (NTRS)

Frost, J. D., Jr.

1974-01-01

A system designed to collect electroencephalographic, electro-oculographic, electromyographic, and head motion data is described. The portable instrumentation provides a rapid and simple means by which neurophysiological data can be obtained by the patient in his home and the taped data returned to the laboratory for analysis. The system was designed primarily for the study of sleep.

Overcoming Misconceptions in Neurophysiology Learning: An Approach Using Color-Coded Animations

ERIC Educational Resources Information Center

Guy, Richard

2012-01-01

Anyone who has taught neurophysiology would be aware of recurring concepts that students find difficult to understand. However, a greater problem is the development of misconceptions that may be difficult to change. For example, one common misconception is that action potentials pass directly across chemical synapses. Difficulties may be…

Syntax as a Reflex: Neurophysiological Evidence for Early Automaticity of Grammatical Processing

ERIC Educational Resources Information Center

Pulvermuller, Friedemann; Shtyrov, Yury; Hasting, Anna S.; Carlyon, Robert P.

2008-01-01

It has been a matter of debate whether the specifically human capacity to process syntactic information draws on attentional resources or is automatic. To address this issue, we recorded neurophysiological indicators of syntactic processing to spoken sentences while subjects were distracted to different degrees from language processing. Subjects…

A Study of the Effectiveness of Sensory Integration Therapy on Neuro-Physiological Development

ERIC Educational Resources Information Center

Reynolds, Christopher; Reynolds, Kathleen Sheena

2010-01-01

Background: Sensory integration theory proposes that because there is plasticity within the central nervous system (the brain is moldable) and because the brain consists of systems that are hierarchically organised, it is possible to stimulate and improve neuro-physiological processing and integration and thereby increase learning capacity.…

Neurophysiology and Neuroanatomy of Reflexive and Voluntary Saccades in Non-Human Primates

ERIC Educational Resources Information Center

Johnston, Kevin; Everling, Stefan

2008-01-01

A multitude of cognitive functions can easily be tested by a number of relatively simple saccadic eye movement tasks. This approach has been employed extensively with patient populations to investigate the functional deficits associated with psychiatric disorders. Neurophysiological studies in non-human primates performing the same tasks have…

Brain Oscillations Forever--Neurophysiology in Future Research of Child Psychiatric Problems

ERIC Educational Resources Information Center

Rothenberger, Aribert

2009-01-01

For decades neurophysiology has successfully contributed to research and clinical care in child psychiatry. Recently, methodological progress has led to a revival of interest in brain oscillations (i.e., a band of periodic neuronal frequencies with a wave-duration from milliseconds to several seconds which may code and decode information). These…

Monitoring Brain Activity of Geriatric Learners with Low-Cost Neurophysiological Technology

ERIC Educational Resources Information Center

Romero-Hall, Enilda; Scott, JoAnne

2017-01-01

Cultural stereotypes rooted in both antiquated data and misinterpretation of data have long perpetuated the belief that older adults are unable to learn new concepts because they are doomed to lose brain cells at an alarming rate during their geriatric years. However, advances in neurophysiological technologies that allow researchers to observe…

Neurophysiologic Analysis of the Effects of Interactive Tailored Health Videos on Attention to Health Messages

ERIC Educational Resources Information Center

Lee, Jung A.

2011-01-01

Web-based tailored approaches hold much promise as effective means for delivering health education and improving public health. This study examines the effects of interactive tailored health videos on attention to health messages using neurophysiological changes measured by Electroencephalogram (EEG) and Electrocardiogram (EKG). Sixty-eight…

Neurophysiological symptoms and aspartame: What is the connection?

PubMed

Choudhary, Arbind Kumar; Lee, Yeong Yeh

2018-06-01

Aspartame (α-aspartyl-l-phenylalanine-o-methyl ester), an artificial sweetener, has been linked to behavioral and cognitive problems. Possible neurophysiological symptoms include learning problems, headache, seizure, migraines, irritable moods, anxiety, depression, and insomnia. The consumption of aspartame, unlike dietary protein, can elevate the levels of phenylalanine and aspartic acid in the brain. These compounds can inhibit the synthesis and release of neurotransmitters, dopamine, norepinephrine, and serotonin, which are known regulators of neurophysiological activity. Aspartame acts as a chemical stressor by elevating plasma cortisol levels and causing the production of excess free radicals. High cortisol levels and excess free radicals may increase the brains vulnerability to oxidative stress which may have adverse effects on neurobehavioral health. We reviewed studies linking neurophysiological symptoms to aspartame usage and conclude that aspartame may be responsible for adverse neurobehavioral health outcomes. Aspartame consumption needs to be approached with caution due to the possible effects on neurobehavioral health. Whether aspartame and its metabolites are safe for general consumption is still debatable due to a lack of consistent data. More research evaluating the neurobehavioral effects of aspartame are required.

The Homemade Alternative: Teaching Human Neurophysiology with Instrumentation Made (Almost) from Scratch

PubMed Central

Hauptman, Stephen; Du Bois, Katherine; Johnson, Bruce R.

2012-01-01

Recording human neurophysiological data in the teaching laboratory generally requires expensive instrumentation. From our experience in developing inexpensive equipment used in teaching neurophysiology laboratory exercises, we offer a strategy for the development of affordable and safe recording of human neurophysiological parameters. There are many resources available to guide the design and construction of electronic equipment that will record human biopotentials. An important consideration is subject safety, and the electrical characteristics of any equipment must meet strict galvanic isolation standards. Wireless data gathering offers the most complete isolation from 120VAC current. As an example, we present a homemade electrocardiogram recording circuit using only inexpensive and readily available components. We outline the feasibility of constructing equipment that meets the needs of the student laboratory for good data collection, and we consider the obstacles likely to be encountered in these projects. If students actively participate in the equipment design and construction, the process can also be a teaching tool. Students may gain a deeper understanding of the human neurobiology by making the electronic data acquisition and its presentation more transparent. PMID:23493343

Proposal for a Standard Format for Neurophysiology Data Recording and Exchange.

PubMed

Stead, Matt; Halford, Jonathan J

2016-10-01

The lack of interoperability between information networks is a significant source of cost in health care. Standardized data formats decrease health care cost, improve quality of care, and facilitate biomedical research. There is no common standard digital format for storing clinical neurophysiologic data. This review proposes a new standard file format for neurophysiology data (the bulk of which is video-electroencephalographic data), entitled the Multiscale Electrophysiology Format, version 3 (MEF3), which is designed to address many of the shortcomings of existing formats. MEF3 provides functionality that addresses many of the limitations of current formats. The proposed improvements include (1) hierarchical file structure with improved organization; (2) greater extensibility for big data applications requiring a large number of channels, signal types, and parallel processing; (3) efficient and flexible lossy or lossless data compression; (4) industry standard multilayered data encryption and time obfuscation that permits sharing of human data without the need for deidentification procedures; (5) resistance to file corruption; (6) facilitation of online and offline review and analysis; and (7) provision of full open source documentation. At this time, there is no other neurophysiology format that supports all of these features. MEF3 is currently gaining industry and academic community support. The authors propose the use of the MEF3 as a standard format for neurophysiology recording and data exchange. Collaboration between industry, professional organizations, research communities, and independent standards organizations is needed to move the project forward.

Human skin wetness perception: psychophysical and neurophysiological bases.

PubMed

Filingeri, Davide; Havenith, George

2015-01-01

The ability to perceive thermal changes in the surrounding environment is critical for survival. However, sensing temperature is not the only factor among the cutaneous sensations to contribute to thermoregulatory responses in humans. Sensing skin wetness (i.e. hygrosensation) is also critical both for behavioral and autonomic adaptations. Although much has been done to define the biophysical role of skin wetness in contributing to thermal homeostasis, little is known on the neurophysiological mechanisms underpinning the ability to sense skin wetness. Humans are not provided with skin humidity receptors (i.e., hygroreceptors) and psychophysical studies have identified potential sensory cues (i.e. thermal and mechanosensory) which could contribute to sensing wetness. Recently, a neurophysiological model of human wetness sensitivity has been developed. In helping clarifying the peripheral and central neural mechanisms involved in sensing skin wetness, this model has provided evidence for the existence of a specific human hygrosensation strategy, which is underpinned by perceptual learning via sensory experience. Remarkably, this strategy seems to be shared by other hygroreceptor-lacking animals. However, questions remain on whether these sensory mechanisms are underpinned by specific neuromolecular pathways in humans. Although the first study on human wetness perception dates back to more than 100 years, it is surprising that the neurophysiological bases of such an important sensory feature have only recently started to be unveiled. Hence, to provide an overview of the current knowledge on human hygrosensation, along with potential directions for future research, this review will examine the psychophysical and neurophysiological bases of human skin wetness perception.

Intraoperative neurophysiological monitoring of the cortico-spinal tract in image-guided mini-invasive neurosurgery.

PubMed

Cordella, Roberto; Acerbi, Francesco; Broggi, Morgan; Vailati, Davide; Nazzi, Vittoria; Schiariti, Marco; Tringali, Giovanni; Ferroli, Paolo; Franzini, Angelo; Broggi, Giovanni

2013-06-01

To evaluate the role of intraoperative neurophysiological monitoring in image-guided mini-invasive neurosurgery. Twenty-one patients were operated under general anaesthesia with the aid of multimodal intraoperative neurophysiological monitoring to remove supratentorials tumors closely related to the cortico-spinal tract. Pre-operative assessment included fMRI scans and tractography that were uploaded into the intraoperative neuro-navigation system. Monitoring consisted in simultaneously recording EEG, electrocorticography, transcranial and direct motor evoked potentials (tMEP and dMEP), somatosensory evoked potentials and subcortical stimulation during the whole procedures. The recording of all the electrophysiological signals was possible in all procedures. SSEP guided the positioning of the strip electrode over the motor cortex (N20 phase inversion) that was used to evoke dMEP and monitor the lower limb motor responses; subcortical stimulation to unveil the spatial relationship between the tumors and motor fibers. Four patients had transient worsening of the symptoms, but only two had a long-term worsening, although not severe, of the pre-op clinical status. Intraoperative neurophysiology has a great value in mini-invasive neurosurgery, especially because the motor cortex is not exposed, consequently it cannot be directly mapped. This report describes a valuable scheme making use of as many electrophysiological signals as possible to constantly monitor the motor functions. A useful method to monitor motor functions in mini-invasive neurosurgery was described. Copyright © 2012 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Neurophysiological localisation of ulnar neuropathy at the elbow: Validation of diagnostic criteria developed by a taskforce of the Danish Society of clinical neurophysiology.

PubMed

Pugdahl, K; Beniczky, S; Wanscher, B; Johnsen, B; Qerama, E; Ballegaard, M; Benedek, K; Juhl, A; Ööpik, M; Selmar, P; Sønderborg, J; Terney, D; Fuglsang-Frederiksen, A

2017-11-01

This study validates consensus criteria for localisation of ulnar neuropathy at elbow (UNE) developed by a taskforce of the Danish Society of Clinical Neurophysiology and compares them to the existing criteria from the American Association of Neuromuscular and Electrodiagnostic Medicine (AANEM). The Danish criteria are based on combinations of conduction slowing in the segments of the elbow and forearm expressed in Z-scores, and difference between the segments in m/s. Examining fibres to several muscles and sensory fibres can increase the certainty of the localisation. Diagnostic accuracy for UNE was evaluated on 181 neurophysiological studies of the ulnar nerve from 171 peer-reviewed patients from a mixed patient-group. The diagnostic reference standard was the consensus diagnosis based on all available clinical, laboratory, and electrodiagnostic information reached by a group of experienced Danish neurophysiologists. The Danish criteria had high specificity (98.4%) and positive predictive value (PPV) (95.2%) and fair sensitivity (76.9%). Compared to the AANEM criteria, the Danish criteria had higher specificity (p<0.001) and lower sensitivity (p=0.02). The Danish consensus criteria for UNE are very specific and have high PPV. The Danish criteria for UNE are reliable and well suited for use in different centres as they are based on Z-scores. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Disorder-specific and shared neurophysiological impairments of attention and inhibition in women with attention-deficit/hyperactivity disorder and women with bipolar disorder.

PubMed

Michelini, G; Kitsune, G L; Hosang, G M; Asherson, P; McLoughlin, G; Kuntsi, J

2016-02-01

In adults, attention-deficit/hyperactivity disorder (ADHD) and bipolar disorder (BD) have certain overlapping symptoms, which can lead to uncertainty regarding the boundaries of the two disorders. Despite evidence of cognitive impairments in both disorders separately, such as in attentional and inhibitory processes, data on direct comparisons across ADHD and BD on cognitive-neurophysiological measures are as yet limited. We directly compared cognitive performance and event-related potential measures from a cued continuous performance test in 20 women with ADHD, 20 women with BD (currently euthymic) and 20 control women. The NoGo-N2 was attenuated in women with BD, reflecting reduced conflict monitoring, compared with women with ADHD and controls (both p < 0.05). Both ADHD and BD groups showed a reduced NoGo-P3, reflecting inhibitory control, compared with controls (both p < 0.05). In addition, the contingent negative variation was significantly reduced in the ADHD group (p = 0.05), with a trend in the BD group (p = 0.07), compared with controls. These findings indicate potential disorder-specific (conflict monitoring) and overlapping (inhibitory control, and potentially response preparation) neurophysiological impairments in women with ADHD and women with BD. The identified neurophysiological parameters further our understanding of neurophysiological impairments in women with ADHD and BD, and are candidate biomarkers that may aid in the identification of the diagnostic boundaries of the two disorders.

77 FR 38282 - Final Test Guidelines; OCSPP 850 Series; Notice of Availability

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-27

... conditions. EPA is changing the title of OPPTS 850.4450 ``Aquatic Plants Field Study, Tier III'' test....4300 ``Terrestrial Plants Field Study, Tier III'' test guideline. Public Draft OPPTS 850.4025 ``Target..., OCSPP 850.4300 ``Terrestrial Plants Field Study.'' The target area test guideline covers a special case...

Characterization of neurophysiologic and neurocognitive biomarkers for use in genomic and clinical outcome studies of schizophrenia.

PubMed

Light, Gregory A; Swerdlow, Neal R; Rissling, Anthony J; Radant, Allen; Sugar, Catherine A; Sprock, Joyce; Pela, Marlena; Geyer, Mark A; Braff, David L

2012-01-01

Endophenotypes are quantitative, laboratory-based measures representing intermediate links in the pathways between genetic variation and the clinical expression of a disorder. Ideal endophenotypes exhibit deficits in patients, are stable over time and across shifts in psychopathology, and are suitable for repeat testing. Unfortunately, many leading candidate endophenotypes in schizophrenia have not been fully characterized simultaneously in large cohorts of patients and controls across these properties. The objectives of this study were to characterize the extent to which widely-used neurophysiological and neurocognitive endophenotypes are: 1) associated with schizophrenia, 2) stable over time, independent of state-related changes, and 3) free of potential practice/maturation or differential attrition effects in schizophrenia patients (SZ) and nonpsychiatric comparison subjects (NCS). Stability of clinical and functional measures was also assessed. Participants (SZ n = 341; NCS n = 205) completed a battery of neurophysiological (MMN, P3a, P50 and N100 indices, PPI, startle habituation, antisaccade), neurocognitive (WRAT-3 Reading, LNS-forward, LNS-reorder, WCST-64, CVLT-II). In addition, patients were rated on clinical symptom severity as well as functional capacity and status measures (GAF, UPSA, SOF). 223 subjects (SZ n = 163; NCS n = 58) returned for retesting after 1 year. Most neurophysiological and neurocognitive measures exhibited medium-to-large deficits in schizophrenia, moderate-to-substantial stability across the retest interval, and were independent of fluctuations in clinical status. Clinical symptoms and functional measures also exhibited substantial stability. A Longitudinal Endophenotype Ranking System (LERS) was created to rank neurophysiological and neurocognitive biomarkers according to their effect sizes across endophenotype criteria. The majority of neurophysiological and neurocognitive measures exhibited deficits in patients, stability over a 1-year interval and did not demonstrate practice or time effects supporting their use as endophenotypes in neural substrate and genomic studies. These measures hold promise for informing the "gene-to-phene gap" in schizophrenia research.

Characterization of Neurophysiologic and Neurocognitive Biomarkers for Use in Genomic and Clinical Outcome Studies of Schizophrenia

PubMed Central

Light, Gregory A.; Swerdlow, Neal R.; Rissling, Anthony J.; Radant, Allen; Sugar, Catherine A.; Sprock, Joyce; Pela, Marlena; Geyer, Mark A.; Braff, David L.

2012-01-01

Background Endophenotypes are quantitative, laboratory-based measures representing intermediate links in the pathways between genetic variation and the clinical expression of a disorder. Ideal endophenotypes exhibit deficits in patients, are stable over time and across shifts in psychopathology, and are suitable for repeat testing. Unfortunately, many leading candidate endophenotypes in schizophrenia have not been fully characterized simultaneously in large cohorts of patients and controls across these properties. The objectives of this study were to characterize the extent to which widely-used neurophysiological and neurocognitive endophenotypes are: 1) associated with schizophrenia, 2) stable over time, independent of state-related changes, and 3) free of potential practice/maturation or differential attrition effects in schizophrenia patients (SZ) and nonpsychiatric comparison subjects (NCS). Stability of clinical and functional measures was also assessed. Methods Participants (SZ n = 341; NCS n = 205) completed a battery of neurophysiological (MMN, P3a, P50 and N100 indices, PPI, startle habituation, antisaccade), neurocognitive (WRAT-3 Reading, LNS-forward, LNS-reorder, WCST-64, CVLT-II). In addition, patients were rated on clinical symptom severity as well as functional capacity and status measures (GAF, UPSA, SOF). 223 subjects (SZ n = 163; NCS n = 58) returned for retesting after 1 year. Results Most neurophysiological and neurocognitive measures exhibited medium-to-large deficits in schizophrenia, moderate-to-substantial stability across the retest interval, and were independent of fluctuations in clinical status. Clinical symptoms and functional measures also exhibited substantial stability. A Longitudinal Endophenotype Ranking System (LERS) was created to rank neurophysiological and neurocognitive biomarkers according to their effect sizes across endophenotype criteria. Conclusions The majority of neurophysiological and neurocognitive measures exhibited deficits in patients, stability over a 1-year interval and did not demonstrate practice or time effects supporting their use as endophenotypes in neural substrate and genomic studies. These measures hold promise for informing the “gene-to-phene gap” in schizophrenia research. PMID:22802938

Objective pain diagnostics: clinical neurophysiology.

PubMed

Garcia-Larrea, L

2012-06-01

Neurophysiological techniques help in diagnosis, prognosis and treatment of chronic pain, and are particularly useful to determine its neuropathic origin. According to current standards, the diagnosis of definite neuropathic pain (NP) needs objective confirmation of a lesion or disease of somatosensory systems, which can be provided by neurophysiological testing. Lesions causing NP mostly concern the pain-temperature pathways, and therefore neurophysiological procedures allowing the specific testing of these pathways (i.e., A-delta and C-fibres, spino-thalamo-cortical tracts) are essential for objective diagnosis. Different techniques to stimulate selectively pain-temperature pathways are discussed. Of these, laser-evoked potentials (LEPs) appear as the easiest and most reliable neurophysiological method of assessing nociceptive function, and their coupling with autonomic responses (e.g., galvanic skin response) and psychophysics (quantitative sensory testing - QST) can still enhance their diagnostic yield. Neurophysiological techniques not exploring specifically nociception, such as standard nerve conduction velocities (NCV) and SEPs to non-noxious stimulation, should be associated to the exploration of nociceptive systems, not only because both may be simultaneously affected to different degrees, but also because some specific painful symptoms, such as paroxysmal discharges, may depend on specific alteration of highly myelinated A-beta fibres. The choice of techniques is determined after anamnesis and clinical exam, and tries to answer a number of questions: (a) is the pain-related to injury of somatosensory pathways?; (b) to what extent are different subsystems affected?; (c) are mechanisms and lesion site in accordance with imaging data?; (d) are results of use for diagnostic or therapeutic follow-up? Neuropathic pain (NP) affects more than 15 million people in Western countries, and its belated diagnosis leads to insufficient or delayed therapy. The use of neurofunctional approaches to obtain a "physiological photograph" of somatosensory function is therefore highly relevant, as it yields significant clues about the type and mechanisms of pain, thus prompting rapid and optimised therapy. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Clinical neurophysiology and quantitative sensory testing in the investigation of orofacial pain and sensory function.

PubMed

Jääskeläinen, Satu K

2004-01-01

Chronic orofacial pain represents a diagnostic and treatment challenge for the clinician. Some conditions, such as atypical facial pain, still lack proper diagnostic criteria, and their etiology is not known. The recent development of neurophysiological methods and quantitative sensory testing for the examination of the trigeminal somatosensory system offers several tools for diagnostic and etiological investigation of orofacial pain. This review presents some of these techniques and the results of their application in studies on orofacial pain and sensory dysfunction. Clinical neurophysiological investigation has greater diagnostic accuracy and sensitivity than clinical examination in the detection of the neurogenic abnormalities of either peripheral or central origin that may underlie symptoms of orofacial pain and sensory dysfunction. Neurophysiological testing may also reveal trigeminal pathology when magnetic resonance imaging has failed to detect it, so these methods should be considered complementary to each other in the investigation of orofacial pain patients. The blink reflex, corneal reflex, jaw jerk, sensory neurography of the inferior alveolar nerve, and the recording of trigeminal somatosensory-evoked potentials with near-nerve stimulation have all proved to be sensitive and reliable in the detection of dysfunction of the myelinated sensory fibers of the trigeminal nerve or its central connections within the brainstem. With appropriately small thermodes, thermal quantitative sensory testing is useful for the detection of trigeminal small-fiber dysfunction (Adelta and C). In neuropathic conditions, it is most sensitive to lesions causing axonal injury. By combining different techniques for investigation of the trigeminal system, an accurate topographical diagnosis and profile of sensory fiber pathology can be determined. Neurophysiological and quantitative sensory tests have already highlighted some similarities among various orofacial pain conditions and have shown heterogeneity within clinical diagnostic categories. With the aid of neurophysiological recordings and quantitative sensory testing, it is possible to approach a mechanism-based classification of orofacial pain.

Vision Science and Adaptive Optics, The State of the Field

PubMed Central

Marcos, Susana; Werner, John S.; Burns, Stephen A; Merigan, William H.; Artal, Pablo; Atchison, David A.; Hampson, Karen M.; Legras, Richard; Lundstrom, Linda; Yoon, Geungyoung; Carroll, Joseph; Choi, Stacey S.; Doble, Nathan; Dubis, Adam M.; Dubra, Alfredo; Elsner, Ann; Jonnal, Ravi; Miller, Donald T.; Paques, Michel; Smithson, Hannah E.; Young, Laura K.; Zhang, Yuhua; Campbell, Melanie; Hunter, Jennifer; Metha, Andrew; Palczewska, Grazyna; Schallek, Jesse; Sincich, Lawrence C.

2017-01-01

Adaptive optics is a relatively new field, yet it is spreading rapidly and allows new questions to be asked about how the visual system is organized. The editors of this feature issue have posed a series of question to scientists involved in using adaptive optics in vision science. The questions are focused on three main areas. In the first we investigate the use of adaptive optics for psychophysical measurements of visual system function and for improving the optics of the eye. In the second, we look at the applications and impact of adaptive optics on retinal imaging and its promise for basic and applied research. In the third, we explore how adaptive optics is being used to improve our understanding of the neurophysiology of the visual system. PMID:28212982

Medical Support and Findings of the Skylab Program

NASA Technical Reports Server (NTRS)

Johnston, Richard S.; Dietlein, Lawrence F.

1975-01-01

Specific equipment used in carrying out Skylab medical experiments is outlined and illustrated. Also included are reviews of the techniques, frequency, and protocols of the tests designed to study the long term effects of weightlessness on the human body. In-flight investigations were an evaluation of the cardiovascular system, a study of metabolic activity, investigations in the field of neurophysiology, the determination of changes in body fluids, a precise measurement of total body metabolism, and a study of crew performance by use of a time and motion experiment. Significant data obtained from in-flight and postflight tests are outlined.

Fatigue in industry.

PubMed Central

Grandjean, E

1979-01-01

Physical fatigue is a painful phenomenon which is localised in overstressed muscles. Mental fatigue is a diffuse sensation of weariness; it is a functional state, one of several intermediate conditions between the two extremes of alarm and sleep. A neurophysiological model of fatigue, involving an activating and inhibitory system has been developed. Fatigue in industrial practice has clinical symptoms: psychic instability, fits of depression and increased liability to illness. Indicators of fatigue are work of performance, subjective feelings of fatigue, electroencephalography, flicker-fusion frequency and various psychomotor and mental tests. Several field studies do, to some extent, confirm the above-mentioned concept of fatigue. PMID:40999

[Progress on neuropsychology and event-related potentials in patients with brain trauma].

PubMed

Dong, Ri-xia; Cai, Wei-xiong; Tang, Tao; Huang, Fu-yin

2010-02-01

With the development of information technology, as one of the research frontiers in neurophysiology, event-related potentials (ERP) is concerned increasingly by international scholars, which provides a feasible and objective method for exploring cognitive function. There are many advances in neuropsychology due to new assessment tool for the last years. The basic theories in the field of ERP and neuropsychology were reviewed in this article. The research and development in evaluating cognitive function of patients with syndrome after brain trauma were focused in this review, and the perspectives for the future research of ERP was also explored.

Multivariable nonlinear analysis of foreign exchange rates

NASA Astrophysics Data System (ADS)

Suzuki, Tomoya; Ikeguchi, Tohru; Suzuki, Masuo

2003-05-01

We analyze the multivariable time series of foreign exchange rates. These are price movements that have often been analyzed, and dealing time intervals and spreads between bid and ask prices. Considering dealing time intervals as event timing such as neurons’ firings, we use raster plots (RPs) and peri-stimulus time histograms (PSTHs) which are popular methods in the field of neurophysiology. Introducing special processings to obtaining RPs and PSTHs time histograms for analyzing exchange rates time series, we discover that there exists dynamical interaction among three variables. We also find that adopting multivariables leads to improvements of prediction accuracy.

Neurophysiologic Evaluation of Early Cognitive Development in High-Risk Infants and Toddlers

ERIC Educational Resources Information Center

deRegnier, Raye-Ann

2005-01-01

New knowledge of the perceptual, discriminative, and memory capabilities of very young infants has opened the door to further evaluation of these abilities in infants who have risk factors for cognitive impairments. A neurophysiologic technique that has been very useful in this regard is the recording of event-related potentials (ERPs). The…

Maternal Behavior Predicts Infant Neurophysiological and Behavioral Attention Processes in the First Year

ERIC Educational Resources Information Center

Swingler, Margaret M.; Perry, Nicole B.; Calkins, Susan D.; Bell, Martha Ann

2017-01-01

We apply a biopsychosocial conceptualization to attention development in the 1st year and examine the role of neurophysiological and social processes on the development of early attention processes. We tested whether maternal behavior measured during 2 mother-child interaction tasks when infants (N = 388) were 5 months predicted infant medial…

Risk and Resilience: Early Manipulation of Macaque Social Experience and Persistent Behavioral and Neurophysiological Outcomes

ERIC Educational Resources Information Center

Stevens, Hanna E.; Leckman, James F.; Coplan, Jeremy D.; Suomi, Stephen J.

2009-01-01

A literature review on macaque monkeys finds that peer rearing of young macaques and rearing of young macaques by mothers that are undergoing variable foraging conditions result in emotional and neurophysiological disturbance. Certain genotypes contribute to resilience to this disturbance. The findings have implications to child mental health and…

Understanding in an Instant: Neurophysiological Evidence for Mechanistic Language Circuits in the Brain

ERIC Educational Resources Information Center

Pulvermuller, Friedemann; Shtyrov, Yury; Hauk, Olaf

2009-01-01

How long does it take the human mind to grasp the idea when hearing or reading a sentence? Neurophysiological methods looking directly at the time course of brain activity indexes of comprehension are critical for finding the answer to this question. As the dominant cognitive approaches, models of serial/cascaded and parallel processing, make…

Neuromuscular deficits after peripheral joint injury: a neurophysiological hypothesis.

PubMed

Ward, Sarah; Pearce, Alan J; Pietrosimone, Brian; Bennell, Kim; Clark, Ross; Bryant, Adam L

2015-03-01

In addition to biomechanical disturbances, peripheral joint injuries (PJIs) can also result in chronic neuromuscular alterations due in part to loss of mechanoreceptor-mediated afferent feedback. An emerging perspective is that PJI should be viewed as a neurophysiological dysfunction, not simply a local injury. Neurophysiological and neuroimaging studies have provided some evidence for central nervous system (CNS) reorganization at both the cortical and spinal levels after PJI. The novel hypothesis proposed is that CNS reorganization is the underlying mechanism for persisting neuromuscular deficits after injury, particularly muscle weakness. There is a lack of direct evidence to support this hypothesis, but future studies utilizing force-matching tasks with superimposed transcranial magnetic stimulation may be help clarify this notion. © 2014 Wiley Periodicals, Inc.

[In search for neurophysiological criteria of altered consciousness].

PubMed

Sviderskaia, N E

2002-01-01

Neurophysiological approaches to brain mechanisms of consciousness are discussed. The concept of spatial synchronization of nervous processes developed by M.N. Livanov is applied to neurophysiological analysis of higher brain functions. However, the spatial synchronization of brain potentials is only a condition for information processing and does not represent it as such. This imposes restrictions on conclusions about the neural mechanisms of consciousness. It is more adequate to use the concept of spatial synchronization in views of consciousness as a psychophysiological level along with sub- and superconsciousness in three-level structure of mind according to P.V. Simonov. Forms of consciousness interaction with other levels concern the problem of altered consciousness and may be reflected in various patterns of spatial organization of brain potentials.

Antiferromagnetic coupling between rare earth ions and semiquinones in a series of 1:1 complexes.

PubMed

Caneschi, Andrea; Dei, Andrea; Gatteschi, Dante; Poussereau, Sandrine; Sorace, Lorenzo

2004-04-07

We use the strategy of diamagnetic substitution for obtaining information on the crystal field effects in paramagnetic rare earth ions using the homologous series of compounds with the diamagnetic tropolonato ligand, Ln(Trp)(HBPz(3))(2), and the paramagnetic semiquinone ligand, Ln(DTBSQ)(HBPz(3))(2), (DTBSQ = 3,5-di-tert-butylsemiquinonato, Trp = tropolonate, HBPz(3)= hydrotrispyrazolylborate) for Ln = Sm(iii), Eu(iii), Gd(iii), Tb(iii), Dy(iii), Ho(iii), Er(iii) or Yb(iii). The X-ray crystal structure of a new form of tropolonate derivative is presented, which shows, as expected, a marked similarity with the structure of the semiquinonate derivative. The Ln(Trp)(HBPz(3))(2) derivatives were then used as a reference for the qualitative determination of crystal field effects in the exchange coupled semiquinone derivatives. Through magnetisation and susceptibility measurements this empirical diamagnetic substitution method evidenced for Er(iii), Tb(iii), Dy(iii) and Yb(iii) derivatives a dominating antiferromagnetic coupling. The increased antiferromagnetic contribution compared to other radical-rare earth metal complexes formed by nitronyl nitroxide ligands may be related to the increased donor strength of the semiquinone ligand.

Rhythmic EEG patterns in extremely preterm infants: Classification and association with brain injury and outcome.

PubMed

Weeke, Lauren C; van Ooijen, Inge M; Groenendaal, Floris; van Huffelen, Alexander C; van Haastert, Ingrid C; van Stam, Carolien; Benders, Manon J; Toet, Mona C; Hellström-Westas, Lena; de Vries, Linda S

2017-12-01

Classify rhythmic EEG patterns in extremely preterm infants and relate these to brain injury and outcome. Retrospective analysis of 77 infants born <28 weeks gestational age (GA) who had a 2-channel EEG during the first 72 h after birth. Patterns detected by the BrainZ seizure detection algorithm were categorized: ictal discharges, periodic epileptiform discharges (PEDs) and other waveforms. Brain injury was assessed with sequential cranial ultrasound (cUS) and MRI at term-equivalent age. Neurodevelopmental outcome was assessed with the BSITD-III (2 years) and WPPSI-III-NL (5 years). Rhythmic patterns were observed in 62.3% (ictal 1.3%, PEDs 44%, other waveforms 86.3%) with multiple patterns in 36.4%. Ictal discharges were only observed in one and excluded from further analyses. The EEG location of the other waveforms (p<0.05), but not PEDs (p=0.238), was significantly associated with head position. No relation was found between the median total duration of each pattern and injury on cUS and MRI or cognition at 2 and 5 years. Clear ictal discharges are rare in extremely preterm infants. PEDs are common but their significance is unclear. Rhythmic waveforms related to head position are likely artefacts. Rhythmic EEG patterns may have a different significance in extremely preterm infants. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Differentiated effects of deep brain stimulation and medication on somatosensory processing in Parkinson's disease.

PubMed

Sridharan, Kousik Sarathy; Højlund, Andreas; Johnsen, Erik Lisbjerg; Sunde, Niels Aagaard; Johansen, Lars Gottfried; Beniczky, Sándor; Østergaard, Karen

2017-07-01

Deep brain stimulation (DBS) and dopaminergic medication effectively alleviate the motor symptoms in Parkinson's disease (PD) patients, but their effects on the sensory symptoms of PD are still not well understood. To explore early somatosensory processing in PD, we recorded magnetoencephalography (MEG) from thirteen DBS-treated PD patients and ten healthy controls during median nerve stimulation. PD patients were measured during DBS-treated, untreated and dopaminergic-medicated states. We focused on early cortical somatosensory processing as indexed by N20m, induced gamma augmentation (31-45Hz and 55-100Hz) and induced beta suppression (13-30Hz). PD patients' motor symptoms were assessed by UPDRS-III. Using Bayesian statistics, we found positive evidence for differentiated effects of treatments on the induced gamma augmentation (31-45Hz) with highest gamma in the dopaminergic-medicated state and lowest in the DBS-treated and untreated states. In contrast, UPDRS-III scores showed beneficial effects of both DBS and dopaminergic medication on the patients' motor symptoms. Furthermore, treatments did not affect the amplitude of N20m. Our results suggest differentiated effects of DBS and dopaminergic medication on cortical somatosensory processing in PD patients despite consistent ameliorating effects of both treatments on PD motor symptoms. The differentiated effect suggests differences in the effect mechanisms of the two treatments. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

The amygdala and basal forebrain as a pathway for motivationally guided attention.

PubMed

Peck, Christopher J; Salzman, C Daniel

2014-10-08

Visual stimuli associated with rewards attract spatial attention. Neurophysiological mechanisms that mediate this process must register both the motivational significance and location of visual stimuli. Recent neurophysiological evidence indicates that the amygdala encodes information about both of these parameters. Furthermore, the firing rate of amygdala neurons predicts the allocation of spatial attention. One neural pathway through which the amygdala might influence attention involves the intimate and bidirectional connections between the amygdala and basal forebrain (BF), a brain area long implicated in attention. Neurons in the rhesus monkey amygdala and BF were therefore recorded simultaneously while subjects performed a detection task in which the stimulus-reward associations of visual stimuli modulated spatial attention. Neurons in BF were spatially selective for reward-predictive stimuli, much like the amygdala. The onset of reward-predictive signals in each brain area suggested different routes of processing for reward-predictive stimuli appearing in the ipsilateral and contralateral fields. Moreover, neurons in the amygdala, but not BF, tracked trial-to-trial fluctuations in spatial attention. These results suggest that the amygdala and BF could play distinct yet inter-related roles in influencing attention elicited by reward-predictive stimuli. Copyright © 2014 the authors 0270-6474/14/3413757-11$15.00/0.

Network dynamics of 3D engineered neuronal cultures: a new experimental model for in-vitro electrophysiology.

PubMed

Frega, Monica; Tedesco, Mariateresa; Massobrio, Paolo; Pesce, Mattia; Martinoia, Sergio

2014-06-30

Despite the extensive use of in-vitro models for neuroscientific investigations and notwithstanding the growing field of network electrophysiology, all studies on cultured cells devoted to elucidate neurophysiological mechanisms and computational properties, are based on 2D neuronal networks. These networks are usually grown onto specific rigid substrates (also with embedded electrodes) and lack of most of the constituents of the in-vivo like environment: cell morphology, cell-to-cell interaction and neuritic outgrowth in all directions. Cells in a brain region develop in a 3D space and interact with a complex multi-cellular environment and extracellular matrix. Under this perspective, 3D networks coupled to micro-transducer arrays, represent a new and powerful in-vitro model capable of better emulating in-vivo physiology. In this work, we present a new experimental paradigm constituted by 3D hippocampal networks coupled to Micro-Electrode-Arrays (MEAs) and we show how the features of the recorded network dynamics differ from the corresponding 2D network model. Further development of the proposed 3D in-vitro model by adding embedded functionalized scaffolds might open new prospects for manipulating, stimulating and recording the neuronal activity to elucidate neurophysiological mechanisms and to design bio-hybrid microsystems.

Network dynamics of 3D engineered neuronal cultures: a new experimental model for in-vitro electrophysiology

PubMed Central

Frega, Monica; Tedesco, Mariateresa; Massobrio, Paolo; Pesce, Mattia; Martinoia, Sergio

2014-01-01

Despite the extensive use of in-vitro models for neuroscientific investigations and notwithstanding the growing field of network electrophysiology, all studies on cultured cells devoted to elucidate neurophysiological mechanisms and computational properties, are based on 2D neuronal networks. These networks are usually grown onto specific rigid substrates (also with embedded electrodes) and lack of most of the constituents of the in-vivo like environment: cell morphology, cell-to-cell interaction and neuritic outgrowth in all directions. Cells in a brain region develop in a 3D space and interact with a complex multi-cellular environment and extracellular matrix. Under this perspective, 3D networks coupled to micro-transducer arrays, represent a new and powerful in-vitro model capable of better emulating in-vivo physiology. In this work, we present a new experimental paradigm constituted by 3D hippocampal networks coupled to Micro-Electrode-Arrays (MEAs) and we show how the features of the recorded network dynamics differ from the corresponding 2D network model. Further development of the proposed 3D in-vitro model by adding embedded functionalized scaffolds might open new prospects for manipulating, stimulating and recording the neuronal activity to elucidate neurophysiological mechanisms and to design bio-hybrid microsystems. PMID:24976386

Disentangling How the Brain is “Wired” in Cortical/Cerebral Visual Impairment (CVI)

PubMed Central

Merabet, Lotfi B.; Mayer, D. Luisa; Bauer, Corinna M.; Wright, Darick; Kran, Barry S.

2017-01-01

Cortical/cerebral visual impairment (CVI) results from perinatal injury to visual processing structures and pathways of the brain and is the most common cause of severe visual impairment/blindness in children in developed countries. Children with CVI display a wide range of visual deficits including decreased visual acuity, impaired visual field function, as well as impairments in higher order visual processing and attention. Together, these visual impairments can dramatically impact upon a child’s development and well-being. Given the complex neurological underpinnings of this condition, CVI is often undiagnosed by eye care practitioners. Furthermore, the neurophysiological basis of CVI in relation to observed visual processing deficits remains poorly understood. Here, we present some of the challenges associated with the clinical assessment and management of individuals with CVI. We discuss how advances in brain imaging are likely to help uncover the underlying neurophysiology of this condition. In particular, we demonstrate how structural and functional neuroimaging approaches can help gain insight into abnormalities of white matter connectivity and cortical activation patterns respectively. Establishing a connection between how changes within the brain relate to visual impairments in CVI will be important for developing effective rehabilitative and education strategies for individuals living with this condition. PMID:28941531

Free will: reconciling German civil law with Libet's neurophysiological studies on the readiness potential.

PubMed

Kawohl, Wolfram; Habermeyer, Elmar

2007-01-01

The free will debate widely exceeds the neuroscientific and philosophical fields due to profound implications for legislation, case law and psychiatric expert opinion. Data from Benjamin Libet's experiments on the readiness potential have been used as an argument against personal responsibility and for changes in the law. Due to the explicit use of the term "free will" in German civil law, the psychiatrist as an expert witness is confronted with this debate. In this article we outline the role of this crucial term in German civil law and we describe the neurophysiologic challenge in the form of Libet's experiments, which is led on three levels: the correctness of the data, the impact on the question of whether free will exists and possible consequences for the law. We conclude that the problem of free will cannot be debated on the basis of the data provided by Libet's experiments and that doubts about the existence of a free will must not lead to changes in the law or in psychiatric expert testimony. Therefore, advice for the psychiatrist as an expert witness is offered on the basis of a psychopathological approach that takes into account cognitive and motivational preconditions and the structure of values and personality. Copyright (c) 2007 John Wiley & Sons, Ltd.

Cerebral localization in the nineteenth century--the birth of a science and its modern consequences.

PubMed

Steinberg, David A

2009-07-01

Although many individuals contributed to the development of the science of cerebral localization, its conceptual framework is the work of a single man--John Hughlings Jackson (1835-1911), a Victorian physician practicing in London. Hughlings Jackson's formulation of a neurological science consisted of an axiomatic basis, an experimental methodology, and a clinical neurophysiology. His axiom--that the brain is an exclusively sensorimotor machine--separated neurology from psychiatry and established a rigorous and sophisticated structure for the brain and mind. Hughlings Jackson's experimental method utilized the focal lesion as a probe of brain function and created an evolutionary structure of somatotopic representation to explain clinical neurophysiology. His scientific theory of cerebral localization can be described as a weighted ordinal representation. Hughlings Jackson's theory of weighted ordinal representation forms the scientific basis for modern neurology. Though this science is utilized daily by every neurologist and forms the basis of neuroscience, the consequences of Hughlings Jackson's ideas are still not generally appreciated. For example, they imply the intrinsic inconsistency of some modern fields of neuroscience and neurology. Thus, "cognitive imaging" and the "neurology of art"--two topics of modern interest--are fundamentally oxymoronic according to the science of cerebral localization. Neuroscientists, therefore, still have much to learn from John Hughlings Jackson.

Disentangling How the Brain is "Wired" in Cortical (Cerebral) Visual Impairment.

PubMed

Merabet, Lotfi B; Mayer, D Luisa; Bauer, Corinna M; Wright, Darick; Kran, Barry S

2017-05-01

Cortical (cerebral) visual impairment (CVI) results from perinatal injury to visual processing structures and pathways of the brain and is the most common cause of severe visual impairment or blindness in children in developed countries. Children with CVI display a wide range of visual deficits including decreased visual acuity, impaired visual field function, as well as impairments in higher-order visual processing and attention. Together, these visual impairments can dramatically influence a child's development and well-being. Given the complex neurologic underpinnings of this condition, CVI is often undiagnosed by eye care practitioners. Furthermore, the neurophysiological basis of CVI in relation to observed visual processing deficits remains poorly understood. Here, we present some of the challenges associated with the clinical assessment and management of individuals with CVI. We discuss how advances in brain imaging are likely to help uncover the underlying neurophysiology of this condition. In particular, we demonstrate how structural and functional neuroimaging approaches can help gain insight into abnormalities of white matter connectivity and cortical activation patterns, respectively. Establishing a connection between how changes within the brain relate to visual impairments in CVI will be important for developing effective rehabilitative and education strategies for individuals living with this condition. Copyright © 2017 Elsevier Inc. All rights reserved.

Seizure clusters: characteristics and treatment.

PubMed

Haut, Sheryl R

2015-04-01

Many patients with epilepsy experience 'clusters' or flurries of seizures, also termed acute repetitive seizures (ARS). Seizure clustering has a significant impact on health and quality of life. This review summarizes recent advances in the definition and neurophysiologic understanding of clustering, the epidemiology and risk factors for clustering and both inpatient and outpatient clinical implications. New treatments for seizure clustering/ARS are perhaps the area of greatest recent progress. Efforts have focused on creating a uniform definition of a seizure cluster. In neurophysiologic studies of refractory epilepsy, seizures within a cluster appear to be self-triggering. Clinical progress has been achieved towards a more precise prevalence of clustering, and consensus guidelines for epilepsy monitoring unit safety. The greatest recent advances are in the study of nonintravenous route of benzodiazepines as rescue medications for seizure clusters/ARS. Rectal benzodiazepines have been very effective but barriers to use exist. New data on buccal, intramuscular and intranasal preparations are anticipated to lead to a greater number of approved treatments. Progesterone may be effective for women who experience catamenial clusters. Seizure clustering is common, particularly in the setting of medically refractory epilepsy. Clustering worsens health and quality of life, and the field requires greater focus on clarifying of definition and clinical implications. Progress towards the development of nonintravenous routes of benzodiazepines has the potential to improve care in this area.

Punishment induced behavioural and neurophysiological variability reveals dopamine-dependent selection of kinematic movement parameters

PubMed Central

Galea, Joseph M.; Ruge, Diane; Buijink, Arthur; Bestmann, Sven; Rothwell, John C.

2013-01-01

Action selection describes the high-level process which selects between competing movements. In animals, behavioural variability is critical for the motor exploration required to select the action which optimizes reward and minimizes cost/punishment, and is guided by dopamine (DA). The aim of this study was to test in humans whether low-level movement parameters are affected by punishment and reward in ways similar to high-level action selection. Moreover, we addressed the proposed dependence of behavioural and neurophysiological variability on DA, and whether this may underpin the exploration of kinematic parameters. Participants performed an out-and-back index finger movement and were instructed that monetary reward and punishment were based on its maximal acceleration (MA). In fact, the feedback was not contingent on the participant’s behaviour but pre-determined. Blocks highly-biased towards punishment were associated with increased MA variability relative to blocks with either reward or without feedback. This increase in behavioural variability was positively correlated with neurophysiological variability, as measured by changes in cortico-spinal excitability with transcranial magnetic stimulation over the primary motor cortex. Following the administration of a DA-antagonist, the variability associated with punishment diminished and the correlation between behavioural and neurophysiological variability no longer existed. Similar changes in variability were not observed when participants executed a pre-determined MA, nor did DA influence resting neurophysiological variability. Thus, under conditions of punishment, DA-dependent processes influence the selection of low-level movement parameters. We propose that the enhanced behavioural variability reflects the exploration of kinematic parameters for less punishing, or conversely more rewarding, outcomes. PMID:23447607

Aquatic exercise and pain neurophysiology education versus aquatic exercise alone for patients with chronic low back pain: a randomized controlled trial.

PubMed

Pires, Diogo; Cruz, Eduardo Brazete; Caeiro, Carmen

2015-06-01

The aim of this study was to compare the effectiveness of a combination of aquatic exercise and pain neurophysiology education with aquatic exercise alone in chronic low back pain patients. Single-blind randomized controlled trial. Outpatient clinic. Sixty-two chronic low back pain patients were randomly allocated to receive aquatic exercise and pain neurophysiology education (n = 30) or aquatic exercise alone (n = 32). Twelve sessions of a 6-week aquatic exercise programme preceded by 2 sessions of pain neurophysiology education. Controls received only 12 sessions of the 6-week aquatic exercise programme. The primary outcomes were pain intensity (Visual Analogue Scale) and functional disability (Quebec Back Pain Disability Scale) at the baseline, 6 weeks after the beginning of the aquatic exercise programme and at the 3 months follow-up. Secondary outcome was kinesiophobia (Tampa Scale of Kinesiophobia). Fifty-five participants completed the study. Analysis using mixed-model ANOVA revealed a significant treatment condition interaction on pain intensity at the 3 months follow-up, favoring the education group (mean SD change: -25.4± 26.7 vs -6.6 ± 30.7, P < 0.005). Although participants in the education group were more likely to report perceived functional benefits from treatment at 3 months follow-up (RR=1.63, 95%CI: 1.01-2.63), no significant differences were found in functional disability and kinesiophobia between groups at any time. This study's findings support the provision of pain neurophysiology education as a clinically effective addition to aquatic exercise. © The Author(s) 2014.

Monitoring and predicting cognitive state and performance via physiological correlates of neuronal signals.

PubMed

Russo, Michael B; Stetz, Melba C; Thomas, Maria L

2005-07-01

Judgment, decision making, and situational awareness are higher-order mental abilities critically important to operational cognitive performance. Higher-order mental abilities rely on intact functioning of multiple brain regions, including the prefrontal, thalamus, and parietal areas. Real-time monitoring of individuals for cognitive performance capacity via an approach based on sampling multiple neurophysiologic signals and integrating those signals with performance prediction models potentially provides a method of supporting warfighters' and commanders' decision making and other operationally relevant mental processes and is consistent with the goals of augmented cognition. Cognitive neurophysiological assessments that directly measure brain function and subsequent cognition include positron emission tomography, functional magnetic resonance imaging, mass spectroscopy, near-infrared spectroscopy, magnetoencephalography, and electroencephalography (EEG); however, most direct measures are not practical to use in operational environments. More practical, albeit indirect measures that are generated by, but removed from the actual neural sources, are movement activity, oculometrics, heart rate, and voice stress signals. The goal of the papers in this section is to describe advances in selected direct and indirect cognitive neurophysiologic monitoring techniques as applied for the ultimate purpose of preventing operational performance failures. These papers present data acquired in a wide variety of environments, including laboratory, simulator, and clinical arenas. The papers discuss cognitive neurophysiologic measures such as digital signal processing wrist-mounted actigraphy; oculometrics including blinks, saccadic eye movements, pupillary movements, the pupil light reflex; and high-frequency EEG. These neurophysiological indices are related to cognitive performance as measured through standard test batteries and simulators with conditions including sleep loss, time on task, and aviation flight-induced fatigue.

Factor Structure and Heritability of Endophenotypes in Schizophrenia: Findings from the Consortium on the Genetics of Schizophrenia (COGS-1)

PubMed Central

Seidman, Larry J.; Hellemann, Gerhard; Nuechterlein, Keith H.; Greenwood, Tiffany A.; Braff, David L.; Cadenhead, Kristin S.; Calkins, Monica E.; Freedman, Robert; Gur, Raquel E.; Gur, Ruben C.; Lazzeroni, Laura C.; Light, Gregory A.; Olincy, Ann; Radant, Allen D.; Siever, Larry J.; Silverman, Jeremy M.; Sprock, Joyce; Stone, William S.; Sugar, Catherine; Swerdlow, Neal R.; Tsuang, Debby W.; Tsuang, Ming T.; Turetsky, Bruce I.; Green, Michael F.

2018-01-01

Background Although many endophenotypes for schizophrenia have been studied individually, few studies have examined the extent to which common neurocognitive and neurophysiological measures reflect shared versus unique endophenotypic factors. It may be possible to distill individual endophenotypes into composite measures that reflect dissociable, genetically informative elements. Methods The first phase of the Consortium on the Genetics of Schizophrenia (COGS-1) is a multisite family study that collected neurocognitive and neurophysiological data between 2003–2008. For these analyses, participants included schizophrenia probands (n=83), their nonpsychotic siblings (n=151), and community comparison subjects (n=209) with complete data on a battery of 12 neurocognitive tests (assessing domains of working memory, declarative memory, vigilance, spatial ability, abstract reasoning, facial emotion processing, and motor speed) and 3 neurophysiological tasks reflecting inhibitory processing (P50 gating, prepulse inhibition and antisaccade tasks). Factor analyses were conducted on the measures for each subject group and across the entire sample. Heritability analyses of factors were performed using SOLAR. Results Analyses yielded 5 distinct factors: 1) Episodic Memory, 2) Working Memory, 3) Perceptual Vigilance, 4) Visual Abstraction, and 5) Inhibitory Processing. Neurophysiological measures had low associations with these factors. The factor structure of endophenotypes was largely comparable across probands, siblings and controls. Significant heritability estimates for the factors ranged from 22% (Episodic Memory) to 39% (Visual Abstraction). Conclusions Neurocognitive measures reflect a meaningful amount of shared variance whereas the neurophysiological measures reflect largely unique contributions as endophenotypes for schizophrenia. Composite endophenotype measures may inform our neurobiological and genetic understanding of schizophrenia. PMID:25682549

Factor structure and heritability of endophenotypes in schizophrenia: findings from the Consortium on the Genetics of Schizophrenia (COGS-1).

PubMed

Seidman, Larry J; Hellemann, Gerhard; Nuechterlein, Keith H; Greenwood, Tiffany A; Braff, David L; Cadenhead, Kristin S; Calkins, Monica E; Freedman, Robert; Gur, Raquel E; Gur, Ruben C; Lazzeroni, Laura C; Light, Gregory A; Olincy, Ann; Radant, Allen D; Siever, Larry J; Silverman, Jeremy M; Sprock, Joyce; Stone, William S; Sugar, Catherine; Swerdlow, Neal R; Tsuang, Debby W; Tsuang, Ming T; Turetsky, Bruce I; Green, Michael F

2015-04-01

Although many endophenotypes for schizophrenia have been studied individually, few studies have examined the extent to which common neurocognitive and neurophysiological measures reflect shared versus unique endophenotypic factors. It may be possible to distill individual endophenotypes into composite measures that reflect dissociable, genetically informative elements. The first phase of the Consortium on the Genetics of Schizophrenia (COGS-1) is a multisite family study that collected neurocognitive and neurophysiological data between 2003 and 2008. For these analyses, participants included schizophrenia probands (n=83), their nonpsychotic siblings (n=151), and community comparison subjects (n=209) with complete data on a battery of 12 neurocognitive tests (assessing domains of working memory, declarative memory, vigilance, spatial ability, abstract reasoning, facial emotion processing, and motor speed) and 3 neurophysiological tasks reflecting inhibitory processing (P50 gating, prepulse inhibition and antisaccade tasks). Factor analyses were conducted on the measures for each subject group and across the entire sample. Heritability analyses of factors were performed using SOLAR. Analyses yielded 5 distinct factors: 1) Episodic Memory, 2) Working Memory, 3) Perceptual Vigilance, 4) Visual Abstraction, and 5) Inhibitory Processing. Neurophysiological measures had low associations with these factors. The factor structure of endophenotypes was largely comparable across probands, siblings and controls. Significant heritability estimates for the factors ranged from 22% (Episodic Memory) to 39% (Visual Abstraction). Neurocognitive measures reflect a meaningful amount of shared variance whereas the neurophysiological measures reflect largely unique contributions as endophenotypes for schizophrenia. Composite endophenotype measures may inform our neurobiological and genetic understanding of schizophrenia. Copyright © 2015 Elsevier B.V. All rights reserved.

[The links between neuropsychology and neurophysiology].

PubMed

Stolarska-Weryńska, Urszula; Biedroń, Agnieszka; Kaciński, Marek

2016-01-01

The aim of the study was to establish current scope of knowledge regarding associations between neurophysiological functioning, neuropsychology and psychoterapy. A systematic review was performed including 93 publications from Science Server, which contains the collections of Elsevier, Springer Journals, SCI-Ex/ICM, MEDLINE/PubMed, and SCOPUS. The works have been selected basing on following key words: 'neuropsychology, neurocognitive correlates, electrodermal response, event related potential, EEG, pupillography, electromiography' out of papers published between 2004-2015. Present reports on the use of neurophysiological methods in psychology can be divided into two areas: experimental research and research of the practical use of conditioning techniques and biofeedback in the treatment of somatic disease. Among the experimental research the following have been distinguished: research based on the startle reflex, physiological reaction to novelty, stress, type/amount of cognitive load and physiological correlates of emotion; research on the neurophysiological correlates of mental disorders, mostly mood and anxiety disorders, and neurocognitive correlates: of memory, attention, learning and intelligence. Among papers regarding the use of neurophysiological methods in psychology two types are the most frequent: on the mechanisms of biofeedback, related mainly to neuro- feedback, which is a quickly expanding method of various attention and mental disorders'treatment, and also research of the use of conditioning techniques in the treatment of mental disorders, especially depression and anxiety. A special place among all the above is taken by the research on electrophysiological correlates of psychotherapy, aiming to differentiate between the efficacy of various psychotherapeutic schools (the largest amount of publications regard the efficacy of cognitive-behavioral psychotherapy) in patients of different age groups and different diagnosis.

Neurocognitive dysfunction in children with β thalassemia major: psychometric, neurophysiologic and radiologic evaluation.

PubMed

Elalfy, M S; Aly, R H; Azzam, H; Aboelftouh, K; Shatla, R H; Tarif, M; Abdatty, M; Elsayed, R M

2017-12-01

To evaluate the impact of iron chelating drugs and serum ferritin on the neurocognitive functions of patients with β thalassemia major (β-TM), using psychometric, neurophysiologic and radiologic tests. Eighty children with β-TM were enrolled into the study and were compared to 40 healthy controls. All participants were evaluated by measuring serum ferritin, neurocognitive assessment by Benton Visual Retention Test, Wechsler Intelligence Scale for Children, Wisconsin Card Sort Test, P300 and magnetic resonance spectroscopy (MRS). WISC in our study showed that 40% of cases were borderline mental function as regards total IQ. Neurophysiologic tests were significantly impaired in patients compared to control group, with significant impairment in those receiving desferrioxamine (DFO). P300 amplitude was significantly lower in cases compared to controls (2.24 and 4.66 uv, respectively), recording the shortest amplitude in patients receiving DFO. Altered metabolic markers in the brain were detected by MRS in the form of reduced N-acetylaspartate to creatine ratio in 78.3% of our cases. There were significant correlations between psychometric tests and both neurophysiologic (P300) and radiologic (MRS) tests. β-TM is associated with neurocognitive impairment that can be assessed by psychometric, neurophysiologic and radiologic tests. The role of hemosiderosis and iron chelation therapy on cognitive functioning still need more research. β-TM: beta thalassemia major; DFO: Dysferal; DFP: Deferiprone; DFX: Deferasirox; WISC: Wechsler Intelligence Scale for Children; VIQ: verbal IQ; PIQ: performance IQ; TIQ: total IQ; BVRT: Benton Visual Retention Test; WCST: Wisconsin Card Sort Test; MRS: Magnetic resonant spectroscopy; NAA/Cr ratio: N-acetylaspartate to creatine ratio.

Pre- and postoperative evaluation of patients with lumbosacral disc herniation by neurophysiological and clinical assessment.

PubMed

Wojtysiak, Magdalena; Huber, Juliusz; Wiertel-Krawczuk, Agnieszka; Szymankiewicz-Szukała, Agnieszka; Moskal, Jakub; Janicki, Jacek

2014-10-01

The application of complex neurophysiological examination including motor evoked potentials (MEP) for pre- and postoperative evaluation of patients experiencing acute sciatica. The assessment of sensitivity and specificity of needle electromyography, MEP, and H-reflex examinations. The comparative analysis of preoperative and postoperative neurophysiological examination. In spite of the fact that complex neurophysiological diagnostic tools seem to be important for interpretation of incompatible results of neuroimaging and clinical examination, especially in the patients qualified for surgical treatment, their application has never been completely analyzed and documented. Pre- and postoperative electromyography, electroneurography, F-waves, H-reflex, and MEP examination were performed in 23 patients with confirmed disc-root conflict at lumbosacral spine. Clinical evaluation included examination of sensory perception for L5-S1 dermatomes, muscles strength with Lovett's scale, deep tendon reflexes, pain intensity with visual analogue scale, and straight leg raising test. Sensitivity of electromyography at rest and MEP examination for evaluation of L5-S1 roots injury was 22% to 63% and 31% to 56% whereas specificity was 71% to 83% and 57% to 86%, respectively. H-reflex sensitivity and specificity for evaluation of S1 root injury were 56% and 67%, respectively. A significant improvement of root latency parameter in postoperative MEP studies as compared with preoperative was recorded for L5 (P = 0.039) and S1 root's levels (P = 0.05). The analysis of the results from neurophysiological tests together with neuroimaging and clinical examination allow for a precise preoperative indication of the lumbosacral roots injury and accurate postoperative evaluation of patients experiencing sciatica. 3.

Human skin wetness perception: psychophysical and neurophysiological bases

PubMed Central

Filingeri, Davide; Havenith, George

2015-01-01

The ability to perceive thermal changes in the surrounding environment is critical for survival. However, sensing temperature is not the only factor among the cutaneous sensations to contribute to thermoregulatory responses in humans. Sensing skin wetness (i.e. hygrosensation) is also critical both for behavioral and autonomic adaptations. Although much has been done to define the biophysical role of skin wetness in contributing to thermal homeostasis, little is known on the neurophysiological mechanisms underpinning the ability to sense skin wetness. Humans are not provided with skin humidity receptors (i.e., hygroreceptors) and psychophysical studies have identified potential sensory cues (i.e. thermal and mechanosensory) which could contribute to sensing wetness. Recently, a neurophysiological model of human wetness sensitivity has been developed. In helping clarifying the peripheral and central neural mechanisms involved in sensing skin wetness, this model has provided evidence for the existence of a specific human hygrosensation strategy, which is underpinned by perceptual learning via sensory experience. Remarkably, this strategy seems to be shared by other hygroreceptor-lacking animals. However, questions remain on whether these sensory mechanisms are underpinned by specific neuromolecular pathways in humans. Although the first study on human wetness perception dates back to more than 100 years, it is surprising that the neurophysiological bases of such an important sensory feature have only recently started to be unveiled. Hence, to provide an overview of the current knowledge on human hygrosensation, along with potential directions for future research, this review will examine the psychophysical and neurophysiological bases of human skin wetness perception. PMID:27227008

Amphiphilic complexes of Ho(iii), Dy(iii), Tb(iii) and Eu(iii) for optical and high field magnetic resonance imaging.

PubMed

Harris, Michael; Henoumont, Céline; Peeters, Wannes; Toyouchi, Shuichi; Vander Elst, Luce; Parac-Vogt, Tatjana N

2018-05-29

Lanthanides, holmium(iii), dysprosium(iii), and terbium(iii), were coordinated to an amphiphilic DOTA bis-coumarin derivative and then further assembled with an amphiphilic europium(iii) DTPA bis-coumarin derivative into mono-disperse micelles. The self-assembled micelles were characterized and assessed for their potential as bimodal contrast agents for high field magnetic resonance and optical imaging applications. All micelles showed a high transverse relaxation (r2) of 46, 34, and 30 s-1 mM-1 at 500 MHz and 37 °C for Dy(iii), Ho(iii) and Tb(iii), respectively, which is a result of the high magnetic moment of these lanthanides and the long rotational correlation time of the micelles. The quantum yield in aqueous solution ranged from 1.8% for Tb/Eu to 1.4% for Dy/Eu and 1.0% for the Ho/Eu micelles. Multi-photon excited emission spectroscopy has shown that due to the two-photon absorption of the coumarin chromophore the characteristic Eu(iii) emission could be observed upon excitation at 800 nm, demonstrating the usefulness of the system for in vivo fluorescence imaging applications. To the best of our knowledge, this is the first example reporting the potential of a holmium(iii) chelate as a negative MRI contrast agent.

Neurophysiology and Neuroanatomy of Reflexive and Volitional Saccades as Revealed by Lesion Studies with Neurological Patients and Transcranial Magnetic Stimulation (TMS)

ERIC Educational Resources Information Center

Muri, Rene M.; Nyffeler, Thomas

2008-01-01

This review discusses the neurophysiology and neuroanatomy of the cortical control of reflexive and volitional saccades in humans. The main focus is on classical lesion studies and studies using the interference method of transcranial magnetic stimulation (TMS). To understand the behavioural function of a region, it is essential to assess…

Electrophysiological Signs of Supplementary-Motor-Area Deficits in High-Functioning Autism but Not Asperger Syndrome: An Examination of Internally Cued Movement-Related Potentials

ERIC Educational Resources Information Center

Enticott, Peter G.; Bradshaw, John L.; Iansek, Robert; Tonge, Bruce J.; Rinehart, Nicole J.

2009-01-01

Aims: Motor dysfunction is common to both autism and Asperger syndrome, but the underlying neurophysiological impairments are unclear. Neurophysiological examinations of motor dysfunction can provide information about likely sites of functional impairment and can contribute to the debate about whether autism and Asperger syndrome are variants of…

Virtual Environments for Soldier Training via Editable Demonstrations (VESTED)

DTIC Science & Technology

2011-04-01

demonstrations as visual depictions of task performance, though sound and especially verbal communications involved with the task can also be essential...or any component cue alone (e.g., Janelle, Champenoy, Coombes , & Mousseau, 2003). Neurophysiology. Recent neurophysiological research has...provides insight about how VESTED functions, what features to modify should it yield less than optimal results, and how to encode, communicate and

[Pain disorders in traumatized individuals - neurophysiology and clinical presentation].

PubMed

Egloff, N; Hirschi, A; von Känel, R

2012-01-18

This overview portrays the salient physiological mechanisms being involved in the clinical manifestation of chronic pain in traumatized patients. A «hypermnesia-hyperarousal-model» is purported to support the neurophysiologic plausibility of the trauma-pain-relationship. We discuss seven characteristic clinical pain entities which alone or in combination can be found in patients with a previous psychological trauma.

Memory formation during anaesthesia: plausibility of a neurophysiological basis

PubMed Central

Veselis, R. A.

2015-01-01

As opposed to conscious, personally relevant (explicit) memories that we can recall at will, implicit (unconscious) memories are prototypical of ‘hidden’ memory; memories that exist, but that we do not know we possess. Nevertheless, our behaviour can be affected by these memories; in fact, these memories allow us to function in an ever-changing world. It is still unclear from behavioural studies whether similar memories can be formed during anaesthesia. Thus, a relevant question is whether implicit memory formation is a realistic possibility during anaesthesia, considering the underlying neurophysiology. A different conceptualization of memory taxonomy is presented, the serial parallel independent model of Tulving, which focuses on dynamic information processing with interactions among different memory systems rather than static classification of different types of memories. The neurophysiological basis for subliminal information processing is considered in the context of brain function as embodied in network interactions. Function of sensory cortices and thalamic activity during anaesthesia are reviewed. The role of sensory and perisensory cortices, in particular the auditory cortex, in support of memory function is discussed. Although improbable, with the current knowledge of neurophysiology one cannot rule out the possibility of memory formation during anaesthesia. PMID:25735711

Imaging transcranial direct current stimulation (tDCS) of the prefrontal cortex-correlation or causality in stimulation-mediated effects?

PubMed

Wörsching, Jana; Padberg, Frank; Ertl-Wagner, Birgit; Kumpf, Ulrike; Kirsch, Beatrice; Keeser, Daniel

2016-10-01

Transcranial current stimulation approaches include neurophysiologically distinct non-invasive brain stimulation techniques widely applied in basic, translational and clinical research: transcranial direct current stimulation (tDCS), oscillating transcranial direct current stimulation (otDCS), transcranial alternating current stimulation (tACS) and transcranial random noise stimulation (tRNS). Prefrontal tDCS seems to be an especially promising tool for clinical practice. In order to effectively modulate relevant neural circuits, systematic research on prefrontal tDCS is needed that uses neuroimaging and neurophysiology measures to specifically target and adjust this method to physiological requirements. This review therefore analyses the various neuroimaging methods used in combination with prefrontal tDCS in healthy and psychiatric populations. First, we provide a systematic overview on applications, computational models and studies combining neuroimaging or neurophysiological measures with tDCS. Second, we categorise these studies in terms of their experimental designs and show that many studies do not vary the experimental conditions to the extent required to demonstrate specific relations between tDCS and its behavioural or neurophysiological effects. Finally, to support best-practice tDCS research we provide a methodological framework for orientation among experimental designs. Copyright © 2016 Elsevier Ltd. All rights reserved.

Neurophysiological basis of creativity in healthy elderly people: a multiscale entropy approach.

PubMed

Ueno, Kanji; Takahashi, Tetsuya; Takahashi, Koichi; Mizukami, Kimiko; Tanaka, Yuji; Wada, Yuji

2015-03-01

Creativity, which presumably involves various connections within and across different neural networks, reportedly underpins the mental well-being of older adults. Multiscale entropy (MSE) can characterize the complexity inherent in EEG dynamics with multiple temporal scales. It can therefore provide useful insight into neural networks. Given that background, we sought to clarify the neurophysiological bases of creativity in healthy elderly subjects by assessing EEG complexity with MSE, with emphasis on assessment of neural networks. We recorded resting state EEG of 20 healthy elderly subjects. MSE was calculated for each subject for continuous 20-s epochs. Their relevance to individual creativity was examined concurrently with intellectual function. Higher individual creativity was linked closely to increased EEG complexity across higher temporal scales, but no significant relation was found with intellectual function (IQ score). Considering the general "loss of complexity" theory of aging, our finding of increased EEG complexity in elderly people with heightened creativity supports the idea that creativity is associated with activated neural networks. Results reported here underscore the potential usefulness of MSE analysis for characterizing the neurophysiological bases of elderly people with heightened creativity. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Pain in trigeminal neuralgia: neurophysiology and measurement: a comprehensive review

PubMed Central

Kumar, S; Rastogi, S; Kumar, S; Mahendra, P; Bansal, M; Chandra, L

2013-01-01

Abstract Trigeminal neuralgia (TN) is defined as sudden, usually unilateral, severe, brief, stabbing recurrent episodes of pain within the distribution of one or more branches of the trigeminal nerve. It is the most frequent cranial neuralgia, the incidence being 1 per 1,000,00 persons per year. Pain attacks start abruptly and last several seconds but may persist 1 to 2 minutes. The attacks are initiated by non painful physical stimulation of specific areas (trigger points or zones) that are located ipsilateral to the pain. After each episode, there is usually a refractive period during which stimulation of the trigger zone will not induce the pain. According to the European Federation of Neurological Societies (EFNS) guidelines on neuropathic pain assessment and the American Academy of Neurology (AAN)-EFNS guidelines on TN management the neurophysiological recording of trigeminal reflexes represents the most useful and reliable test for the neurophysiological diagnosis of trigeminal pains. The present article discusses different techniques for investigation of the trigeminal system by which an accurate topographical diagnosis and profile of sensory fiber pathology can be determined. With the aid of neurophysiological recordings and quantitative sensory testing, it is possible to approach a mechanism-based classification of orofacial pain. PMID:24701256

Pain in trigeminal neuralgia: neurophysiology and measurement: a comprehensive review.

PubMed

Kumar, S; Rastogi, S; Kumar, S; Mahendra, P; Bansal, M; Chandra, L

2013-01-01

Trigeminal neuralgia (TN) is defined as sudden, usually unilateral, severe, brief, stabbing recurrent episodes of pain within the distribution of one or more branches of the trigeminal nerve. It is the most frequent cranial neuralgia, the incidence being 1 per 1,000,00 persons per year. Pain attacks start abruptly and last several seconds but may persist 1 to 2 minutes. The attacks are initiated by non painful physical stimulation of specific areas (trigger points or zones) that are located ipsilateral to the pain. After each episode, there is usually a refractive period during which stimulation of the trigger zone will not induce the pain. According to the European Federation of Neurological Societies (EFNS) guidelines on neuropathic pain assessment and the American Academy of Neurology (AAN)-EFNS guidelines on TN management the neurophysiological recording of trigeminal reflexes represents the most useful and reliable test for the neurophysiological diagnosis of trigeminal pains. The present article discusses different techniques for investigation of the trigeminal system by which an accurate topographical diagnosis and profile of sensory fiber pathology can be determined. With the aid of neurophysiological recordings and quantitative sensory testing, it is possible to approach a mechanism-based classification of orofacial pain.

Psychological pain interventions and neurophysiology: implications for a mechanism-based approach.

PubMed

Flor, Herta

2014-01-01

This article provides an illustrative overview of neurophysiological changes related to acute and chronic pain involving structural and functional brain changes, which might be the targets of psychological interventions. A number of psychological pain treatments have been examined with respect to their effects on brain activity, ranging from cognitive- and operant behavioral interventions, meditation and hypnosis, to neuro- and biofeedback, discrimination training, imagery and mirror treatment, as well as virtual reality and placebo applications. These treatments affect both ascending and descending aspects of pain processing and act through brain mechanisms that involve sensorimotor areas as well as those involved in affective-motivational and cognitive-evaluative aspects. The analysis of neurophysiological changes related to effective psychological pain treatment can help to identify subgroups of patients with chronic pain who might profit from different interventions, can aid in predicting treatment outcome, and can assist in identifying responders and nonresponders, thus enhancing the efficacy and efficiency of psychological interventions. Moreover, new treatment targets can be developed and tested. Finally, the use of neurophysiological measures can also aid in motivating patients to participate in psychological interventions and can increase their acceptance in clinical practice. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Neural correlates of math anxiety - an overview and implications.

PubMed

Artemenko, Christina; Daroczy, Gabriella; Nuerk, Hans-Christoph

2015-01-01

Math anxiety is a common phenomenon which can have a negative impact on numerical and arithmetic performance. However, so far little is known about the underlying neurocognitive mechanisms. This mini review provides an overview of studies investigating the neural correlates of math anxiety which provide several hints regarding its influence on math performance: while behavioral studies mostly observe an influence of math anxiety on difficult math tasks, neurophysiological studies show that processing efficiency is already affected in basic number processing. Overall, the neurocognitive literature suggests that (i) math anxiety elicits emotion- and pain-related activation during and before math activities, (ii) that the negative emotional response to math anxiety impairs processing efficiency, and (iii) that math deficits triggered by math anxiety may be compensated for by modulating the cognitive control or emotional regulation network. However, activation differs strongly between studies, depending on tasks, paradigms, and samples. We conclude that neural correlates can help to understand and explore the processes underlying math anxiety, but the data are not very consistent yet.

Neural correlates of math anxiety – an overview and implications

PubMed Central

Artemenko, Christina; Daroczy, Gabriella; Nuerk, Hans-Christoph

2015-01-01

Math anxiety is a common phenomenon which can have a negative impact on numerical and arithmetic performance. However, so far little is known about the underlying neurocognitive mechanisms. This mini review provides an overview of studies investigating the neural correlates of math anxiety which provide several hints regarding its influence on math performance: while behavioral studies mostly observe an influence of math anxiety on difficult math tasks, neurophysiological studies show that processing efficiency is already affected in basic number processing. Overall, the neurocognitive literature suggests that (i) math anxiety elicits emotion- and pain-related activation during and before math activities, (ii) that the negative emotional response to math anxiety impairs processing efficiency, and (iii) that math deficits triggered by math anxiety may be compensated for by modulating the cognitive control or emotional regulation network. However, activation differs strongly between studies, depending on tasks, paradigms, and samples. We conclude that neural correlates can help to understand and explore the processes underlying math anxiety, but the data are not very consistent yet. PMID:26388824

Respiratory motor training and neuromuscular plasticity in patients with chronic obstructive pulmonary disease: A pilot study.

PubMed

Ovechkin, Alexander V; Sayenko, Dimitry G; Ovechkina, Elena N; Aslan, Sevda C; Pitts, Teresa; Folz, Rodney J

2016-07-15

The objective of this study was to examine the feasibility of a full-scale investigation of the neurophysiological mechanisms of COPD-induced respiratory neuromuscular control deficits. Characterization of respiratory single- and multi-muscle activation patterns using surface electromyography (sEMG) were assessed along with functional measures at baseline and following 21±2 (mean±SD) sessions of respiratory motor training (RMT) performed during a one-month period in four patients with GOLD stage II or III COPD. Pre-training, the individuals with COPD showed significantly increased (p<0.05) overall respiratory muscle activity and disorganized multi-muscle activation patterns in association with lowered spirometrical measures and decreased fast- and slow-twitch fiber activity as compared to healthy controls (N=4). Following RMT, functional and respiratory sEMG activation outcomes during quite breathing and forced expiratory efforts were improved suggesting that functional improvements, induced by task-specific RMT, are evidence respiratory neuromuscular networks re-organization. Published by Elsevier B.V.

Imaging the Perivascular Space as a Potential Biomarker of Neurovascular and Neurodegenerative Diseases.

PubMed

Ramirez, Joel; Berezuk, Courtney; McNeely, Alicia A; Gao, Fuqiang; McLaurin, JoAnne; Black, Sandra E

2016-03-01

Although the brain lacks conventional lymphatic vessels found in peripheral tissue, evidence suggests that the space surrounding the vasculature serves a similar role in the clearance of fluid and metabolic waste from the brain. With aging, neurodegeneration, and cerebrovascular disease, these microscopic perivascular spaces can become enlarged, allowing for visualization and quantification on structural MRI. The purpose of this review is to: (i) describe some of the recent pre-clinical findings from basic science that shed light on the potential neurophysiological mechanisms driving glymphatic and perivascular waste clearance, (ii) review some of the pathobiological etiologies that may lead to MRI-visible enlarged perivascular spaces (ePVS), (iii) describe the possible clinical implications of ePVS, (iv) evaluate existing qualitative and quantitative techniques used for measuring ePVS burden, and (v) propose future avenues of research that may improve our understanding of this potential clinical neuroimaging biomarker for fluid and metabolic waste clearance dysfunction in neurodegenerative and neurovascular diseases.

The Glycine Synaptic Receptor: Evidence That Strychnine Binding Is Associated with the Ionic Conductance Mechanism

PubMed Central

Young, Anne B.; Snyder, Solomon H.

1974-01-01

The ability of a series of anions to inhibit [3H]strychnine binding to spinal cord synaptic membranes correlates closely with their neurophysiologic capacity to reverse inhibitory postsynaptic potentials in the mammalian spinal cord. Seven neurophysiologically active anions are also effective inhibitors of [3H]strychnine binding with mean effective doses ranging from 160 to 620 mM. Seven other anions that are ineffective neurophysiologically also fail to alter strychnine binding. Chloride inhibits strychnine binding in a noncompetitive fashion. Hill plots of the displacement of [3H]strychnine by chloride give coefficients of 2.3-2.7. The inhibition of strychnine binding by these anions suggests that strychnine binding is closely associated with the ionic conductance mechanism for chloride in the glycine receptor. PMID:4372600

Pudendal nerve neuromodulation with neurophysiology guidance: a potential treatment option for refractory chronic pelvi-perineal pain.

PubMed

Carmel, Maude; Lebel, Michel; Tu, Le Mai

2010-05-01

Refractory chronic pelvi-perineal pain (RCPPP) is a challenging entity that has devastating consequences for patient's quality of life. Many etiologies have been proposed including pudendal neuralgia. Multiple treatment options are used but the reported results are sub-optimal and temporary. In this article, we present the technique of pudendal nerve neuromodulation with neurophysiology guidance as a treatment option for RCPPP. This technique is a two-step procedure that includes electrode implantation under neurophysiology guidance followed by the implantation of a permanent generator after a successful trial period. We report the cases of three women who underwent this procedure as a last-resort treatment option. After 2 years of follow-up, their symptoms are still significantly improved. No major complication occurred.

Airborne Acoustic Perception by a Jumping Spider.

PubMed

Shamble, Paul S; Menda, Gil; Golden, James R; Nitzany, Eyal I; Walden, Katherine; Beatus, Tsevi; Elias, Damian O; Cohen, Itai; Miles, Ronald N; Hoy, Ronald R

2016-11-07

Jumping spiders (Salticidae) are famous for their visually driven behaviors [1]. Here, however, we present behavioral and neurophysiological evidence that these animals also perceive and respond to airborne acoustic stimuli, even when the distance between the animal and the sound source is relatively large (∼3 m) and with stimulus amplitudes at the position of the spider of ∼65 dB sound pressure level (SPL). Behavioral experiments with the jumping spider Phidippus audax reveal that these animals respond to low-frequency sounds (80 Hz; 65 dB SPL) by freezing-a common anti-predatory behavior characteristic of an acoustic startle response. Neurophysiological recordings from auditory-sensitive neural units in the brains of these jumping spiders showed responses to low-frequency tones (80 Hz at ∼65 dB SPL)-recordings that also represent the first record of acoustically responsive neural units in the jumping spider brain. Responses persisted even when the distances between spider and stimulus source exceeded 3 m and under anechoic conditions. Thus, these spiders appear able to detect airborne sound at distances in the acoustic far-field region, beyond the near-field range often thought to bound acoustic perception in arthropods that lack tympanic ears (e.g., spiders) [2]. Furthermore, direct mechanical stimulation of hairs on the patella of the foreleg was sufficient to generate responses in neural units that also responded to airborne acoustic stimuli-evidence that these hairs likely play a role in the detection of acoustic cues. We suggest that these auditory responses enable the detection of predators and facilitate an acoustic startle response. VIDEO ABSTRACT. Copyright © 2016 Elsevier Ltd. All rights reserved.

Electroencephalographic neurofeedback: Level of evidence in mental and brain disorders and suggestions for good clinical practice.

PubMed

Micoulaud-Franchi, J-A; McGonigal, A; Lopez, R; Daudet, C; Kotwas, I; Bartolomei, F

2015-12-01

The technique of electroencephalographic neurofeedback (EEG NF) emerged in the 1970s and is a technique that measures a subject's EEG signal, processes it in real time, extracts a parameter of interest and presents this information in visual or auditory form. The goal is to effectuate a behavioural modification by modulating brain activity. The EEG NF opens new therapeutic possibilities in the fields of psychiatry and neurology. However, the development of EEG NF in clinical practice requires (i) a good level of evidence of therapeutic efficacy of this technique, (ii) a good practice guide for this technique. Firstly, this article investigates selected trials with the following criteria: study design with controlled, randomized, and open or blind protocol, primary endpoint related to the mental and brain disorders treated and assessed with standardized measurement tools, identifiable EEG neurophysiological targets, underpinned by pathophysiological relevance. Trials were found for: epilepsies, migraine, stroke, chronic insomnia, attentional-deficit/hyperactivity disorder (ADHD), autism spectrum disorder, major depressive disorder, anxiety disorders, addictive disorders, psychotic disorders. Secondly, this article investigates the principles of neurofeedback therapy in line with learning theory. Different underlying therapeutic models are presented didactically between two continua: a continuum between implicit and explicit learning and a continuum between the biomedical model (centred on "the disease") and integrative biopsychosocial model of health (centred on "the illness"). The main relevant learning model is to link neurofeedback therapy with the field of cognitive remediation techniques. The methodological specificity of neurofeedback is to be guided by biologically relevant neurophysiological parameters. Guidelines for good clinical practice of EEG NF concerning technical issues of electrophysiology and of learning are suggested. These require validation by institutional structures for the clinical practice of EEG NF. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Prevalence of Complications in Intraoperative Magnetic Resonance Imaging Combined with Neurophysiologic Monitoring.

PubMed

Sarnthein, Johannes; Lüchinger, Roger; Piccirelli, Marco; Regli, Luca; Bozinov, Oliver

2016-09-01

High-field intraoperative magnetic resonance imaging (ioMRI) is becoming increasingly available in neurosurgery centers, where it has to be combined with intraoperative neurophysiologic monitoring (IONM). IONM needle electrodes remain on the patient during ioMRI and may cause image distortions and burns. We tested magnetic resonance (MR) -heating experimentally and investigated the prevalence of complications. We studied electrodes that are certified for IONM, but not "MR conditional." They consist of copper cables (length, 1.5 m) and needles made of either stainless steel (ferromagnetic) or paramagnetic platinum/iridium alloy. We simulated an ioMRI session with gel and measured the temperature increase with optical fibers. We measured the force that an electrode experiences in the magnetic field. Between 2013 and 2016, we prospectively documented subcutaneous needle electrodes that remained in the patient during intraoperative 3 Tesla ioMRI scans. The in vitro testing of the electrodes produced a maximum heating (ΔT = 3.9°C) and force of 0.026 N. We placed 1237 subcutaneous needles in 57 surgical procedures with combined IONM and ioMRI, where needles remained in place during ioMRI. One patient suffered a skin burn on the shoulder. All other electrodes had no side effects. We have corroborated the history of safe use for electrodes with 1.5 m cable in a 3T MRI scanner and demonstrated their use. Nevertheless, heating cannot be excluded, as it depends on location and cable placement. When leaving electrodes in place during ioMRI, risks and benefits have to be carefully evaluated for each patient. Copyright © 2016 Elsevier Inc. All rights reserved.

German Emergency Care in Neurosurgery and Military Neurology during World War II, 1939-1945.

PubMed

Stahnisch, Frank W

2016-01-01

A critical analysis of the historical involvement of neurology and neurosurgery in military emergency care services enables us to better contextualize and appreciate the development of modern neurology at large. Wartime neurosurgery and civil brain science during the German Nazi period tightly coalesced in examining the specific injury types, which military neurosurgeons such as Wilhelm Toennis, Klaus Joachim Zuelch, and Georg Merrem encountered and treated based on their neurophysiological understanding gained from earlier peacetime research. Collaborative associations with Dr. Toennis in particular proved to be highly beneficial to other military neurologists and neurosurgeons during World War II and beyond. This article also discusses the prewar developments and considers the fate of German neurosurgeons and military neurologists after the war. The envisaged dynamic concepts of fast action, reaction, and recycling, which contemporary physicians had intensively studied in the preceding scientific experiments in their neurophysiological laboratories, had already been introduced into neurological surgery during the interwar period. In retrospect, World War II emergency rescue units greatly strengthened military operations through an active process of 'recycling' indispensable army personnel. Neurosurgical emergency chains thereby introduced another decisive step in the modernization of warfare, in that they increased the momentum of military mobility in the field. Notwithstanding the violence of warfare and the often inhumane ways in which such knowledge in the field of emergency neurology was gained, the protagonists among the group of experts in military neurology and neurosurgery strongly contributed to the postwar clinical neuroscience community in Germany. In differing political pretexts, this became visible in both East Germany and West Germany after the war, while the specific military and political conditions under which this knowledge of emergency medicine was obtained have largely been forgotten. © 2016 S. Karger AG, Basel.

Structural and functional correlates of visual field asymmetry in the human brain by diffusion kurtosis MRI and functional MRI.

PubMed

O'Connell, Caitlin; Ho, Leon C; Murphy, Matthew C; Conner, Ian P; Wollstein, Gadi; Cham, Rakie; Chan, Kevin C

2016-11-09

Human visual performance has been observed to show superiority in localized regions of the visual field across many classes of stimuli. However, the underlying neural mechanisms remain unclear. This study aims to determine whether the visual information processing in the human brain is dependent on the location of stimuli in the visual field and the corresponding neuroarchitecture using blood-oxygenation-level-dependent functional MRI (fMRI) and diffusion kurtosis MRI, respectively, in 15 healthy individuals at 3 T. In fMRI, visual stimulation to the lower hemifield showed stronger brain responses and larger brain activation volumes than the upper hemifield, indicative of the differential sensitivity of the human brain across the visual field. In diffusion kurtosis MRI, the brain regions mapping to the lower visual field showed higher mean kurtosis, but not fractional anisotropy or mean diffusivity compared with the upper visual field. These results suggested the different distributions of microstructural organization across visual field brain representations. There was also a strong positive relationship between diffusion kurtosis and fMRI responses in the lower field brain representations. In summary, this study suggested the structural and functional brain involvements in the asymmetry of visual field responses in humans, and is important to the neurophysiological and psychological understanding of human visual information processing.

Hexaammine Complexes of Cr(III) and Co(III): A Spectral Study.

ERIC Educational Resources Information Center

Brown, D. R.; Pavlis, R. R.

1985-01-01

Procedures are provided for experiments containing complex ions with octahedral symmetry, hexaamminecobalt(III) chloride and hexaamminechromium(III) nitrate, so students can interpret fully the ultra violet/visible spectra of the complex cations in terms of the ligand field parameters, 10 "Dq," the Racah interelectron repulsion parameters, "B,"…

Antifeedant compounds from three species of Apiaceae active against the field slug, Deroceras reticulatum (Muller).

PubMed

Birkett, Michael A; Dodds, Catherine J; Henderson, Ian F; Leake, Lucy D; Pickett, John A; Selby, Martin J; Watson, Peter

2004-03-01

Extracts of volatiles from foliage of three plants in the Apiaceae, Conium maculatum L. (hemlock), Coriandrum sativum L. (coriander), and Petroselinum crispum Mill. (Nym.) (parsley), previously shown to exhibit antifeedant activity in assays with the field slug, Deroceras reticulatum (Muller) (Limacidae: Pulmonata), were studied further to identify the active components. Coupled gas chromatography-mass spectrometry (GC-MS) and neurophysiological assays using tentacle nerve preparations resulted in the identification of 11 active compounds from the three extracts. Wheat flour feeding bioassays were used to determine which of these compounds had the highest antifeedant activity. One of the most active compounds was the alkaloid gamma-coniceine, from C. maculatum. The role of potentially toxic alkaloids as semiochemicals and the potential for using such compounds as crop protection agents to prevent slug feeding damage is discussed.

Binocular Vision

PubMed Central

Blake, Randolph; Wilson, Hugh

2010-01-01

This essay reviews major developments –empirical and theoretical –in the field of binocular vision during the last 25 years. We limit our survey primarily to work on human stereopsis, binocular rivalry and binocular contrast summation, with discussion where relevant of single-unit neurophysiology and human brain imaging. We identify several key controversies that have stimulated important work on these problems. In the case of stereopsis those controversies include position versus phase encoding of disparity, dependence of disparity limits on spatial scale, role of occlusion in binocular depth and surface perception, and motion in 3D. In the case of binocular rivalry, controversies include eye versus stimulus rivalry, role of “top-down” influences on rivalry dynamics, and the interaction of binocular rivalry and stereopsis. Concerning binocular contrast summation, the essay focuses on two representative models that highlight the evolving complexity in this field of study. PMID:20951722

Vision science and adaptive optics, the state of the field.

PubMed

Marcos, Susana; Werner, John S; Burns, Stephen A; Merigan, William H; Artal, Pablo; Atchison, David A; Hampson, Karen M; Legras, Richard; Lundstrom, Linda; Yoon, Geungyoung; Carroll, Joseph; Choi, Stacey S; Doble, Nathan; Dubis, Adam M; Dubra, Alfredo; Elsner, Ann; Jonnal, Ravi; Miller, Donald T; Paques, Michel; Smithson, Hannah E; Young, Laura K; Zhang, Yuhua; Campbell, Melanie; Hunter, Jennifer; Metha, Andrew; Palczewska, Grazyna; Schallek, Jesse; Sincich, Lawrence C

2017-03-01

Adaptive optics is a relatively new field, yet it is spreading rapidly and allows new questions to be asked about how the visual system is organized. The editors of this feature issue have posed a series of question to scientists involved in using adaptive optics in vision science. The questions are focused on three main areas. In the first we investigate the use of adaptive optics for psychophysical measurements of visual system function and for improving the optics of the eye. In the second, we look at the applications and impact of adaptive optics on retinal imaging and its promise for basic and applied research. In the third, we explore how adaptive optics is being used to improve our understanding of the neurophysiology of the visual system. Copyright © 2017 Elsevier Ltd. All rights reserved.

Where have we been? Where are we going?

PubMed

Gildenberg, P L

1997-01-01

The field of human stereotactic and functional neurosurgery is 50 years old. It began with the pioneering work of Spiegel and Wycis, who developed an apparatus to be used in human neurosurgery designed like the Horsley-Clarke apparatus invented for animal experimentation 40 years earlier, but based on targeting by intracerebral landmarks. During the past half century, the field of stereotactic surgery has evolved from a small field involving a handful of scientists to a field dominated by a technology that is permeating all of neurosurgery. A review of the scientific programs and activities of the World Society for Stereotactic and Functional Neurosurgery reflects the changing level of activity in these fields, the waxing and waning of functional neurosurgery that is now vital and active, and the evolution of stereotactic guidance into the field of computer-assisted neurosurgery. Functional neurosurgery involves the application of human neurophysiology to the treatment of various diseases that produce malfunction of the nervous system, and remains the domain of those few neurosurgeons well versed in neurological pathophysiology. Image-based or computerized stereotactic surgery, on the other hand, is used in those procedures common to neurosurgery, and should be available to any operating neurosurgeon.

Neurophysiological findings relevant to echolocation in marine animals

NASA Technical Reports Server (NTRS)

Bullock, T. H.; Ridgway, S. H.

1972-01-01

A review of echolocation mechanisms in marine mammals, chiefly porpoises, is given. Data cover peripheral auditory and central neurophysiological specializations favorable to the analysis of echolocating clicks and their echoes. Conclusions show (1) signals are received from 50 up to at least 135 kHz, (2) sound is received through the mandible skin, and (3) the midbrain sites are insensitive to low frequencies (below 6 kHz).

Benefit of neurophysiologic monitoring for pediatric cardiac surgery.

PubMed

Austin, E H; Edmonds, H L; Auden, S M; Seremet, V; Niznik, G; Sehic, A; Sowell, M K; Cheppo, C D; Corlett, K M

1997-11-01

Pediatric patients undergoing repair of congenital cardiac abnormalities have a significant risk of an adverse neurologic event. Therefore this retrospective cohort study examined the potential benefit of interventions based on intraoperative neurophysiologic monitoring in decreasing both postoperative neurologic sequelae and length of hospital stay as a cost proxy. With informed parental consent approved by the institutional review board, electroencephalography, transcranial Doppler ultrasonic measurement of middle cerebral artery blood flow velocity, and transcranial near-infrared cerebral oximetry were monitored in 250 patients. An interventional algorithm was used to detect and correct specific deficiencies in cerebral perfusion or oxygenation or to increase cerebral tolerance to ischemia or hypoxia. Noteworthy changes in brain perfusion or metabolism were observed in 176 of 250 (70%) patients. Intervention that altered patient management was initially deemed appropriate in 130 of 176 (74%) patients with neurophysiologic changes. Obvious neurologic sequelae (i.e., seizure, movement, vision or speech disorder) occurred in five of 74 (7%) patients without noteworthy change, seven of 130 (6%) patients with intervention, and 12 of 46 (26%) patients without intervention (p = 0.001). Survivors' median length of stay was 6 days in the no-change and intervention groups but 9 days in the no-intervention group. In addition, the percentage of patients in the no-intervention group discharged from the hospital within 1 week (32%) was significantly less than that in either the intervention (51%, p = 0.05) or no-change (58%, p = 0.01) groups. On the basis of an estimated hospital neurologic complication cost of $1500 per day, break-even analysis justified a hospital expenditure for neurophysiologic monitoring of $2142 per case. Interventions based on neurophysiologic monitoring appear to decrease the incidence of postoperative neurologic sequelae and reduce the length of stay. Inasmuch as the break-even cost for neurophysiologic monitoring is more than four times the actual average charge, both patients and hospital may profit from this service. Because this study was not a truly randomized clinical trial, unintentional statistical bias may have occurred and caution is urged in interpreting the magnitude of apparent intergroup outcome differences.

Neurophysiologic Correlates of Post-stroke Mood and Emotional Control

PubMed Central

Doruk, Deniz; Simis, Marcel; Imamura, Marta; Brunoni, André R.; Morales-Quezada, Leon; Anghinah, Renato; Fregni, Felipe; Battistella, Linamara R.

2016-01-01

Objective: Emotional disturbance is a common complication of stroke significantly affecting functional recovery and quality of life. Identifying relevant neurophysiologic markers associated with post-stroke emotional disturbance may lead to a better understanding of this disabling condition, guiding the diagnosis, development of new interventions and the assessments of treatment response. Methods: Thirty-five subjects with chronic stroke were enrolled in this study. The emotion sub-domain of Stroke Impact Scale (SIS-Emotion) was used to assess post-stroke mood and emotional control. The relation between SIS-Emotion and neurophysiologic measures was assessed by using covariance mapping and univariate linear regression. Multivariate analyses were conducted to identify and adjust for potential confounders. Neurophysiologic measures included power asymmetry and coherence assessed by electroencephalography (EEG); and motor threshold, intracortical inhibition (ICI) and intracortical facilitation (ICF) measured by transcranial magnetic stimulation (TMS). Results: Lower scores on SIS-Emotion was associated with (1) frontal EEG power asymmetry in alpha and beta bands, (2) central EEG power asymmetry in alpha and theta bands, and (3) lower inter-hemispheric coherence over frontal and central areas in alpha band. SIS-Emotion also correlated with higher ICF and MT in the unlesioned hemisphere as measured by TMS. Conclusions: To our knowledge, this is the first study using EEG and TMS to index neurophysiologic changes associated with post-stroke mood and emotional control. Our results suggest that inter-hemispheric imbalance measured by EEG power and coherence, as well as an increased ICF in the unlesioned hemisphere measured by TMS might be relevant markers associated with post-stroke mood and emotional control which can guide future studies investigating new diagnostic and treatment modalities in stroke rehabilitation. PMID:27625600

How the nerves reached the muscle: Bernard Katz, Stephen W. Kuffler, and John C. Eccles-Certain implications of exile for the development of twentieth-century neurophysiology.

PubMed

Stahnisch, Frank W

2017-01-01

This article explores the work by Bernard Katz (1911-2003), Stephen W. Kuffler (1913-1980), and John C. Eccles (1903-1997) on the nerve-muscle junction as a milestone in twentieth-century neurophysiology with wider scientific implications. The historical question is approached from two perspectives: (a) an investigation of twentieth-century solutions to a longer physiological dispute and (b) an examination of a new kind of laboratory and academic cooperation. From this vantage point, the work pursued in Sydney by Sir John Carew Eccles' team on the neuromuscular junction is particularly valuable, since it contributed a central functional element to modern physiological understanding regarding the function and structure of the human and animal nervous system. The reflex model of neuromuscular action had already been advanced by neuroanatomists such as Georg Prochaska (1749-1820) in Bohemia since the eighteenth century. It became a major component of neurophysiological theories during the nineteenth century, based on the law associated with the names of François Magendie (1783-1855) in France and Charles Bell (1774-1842) in Britain regarding the functional differences of the sensory and motor spinal nerves. Yet, it was not until the beginning of the twentieth century that both the histological and the neurophysiological understanding of the nerve-muscle connection became entirely understood and the chemical versus electrical transmission further elicited as the mechanisms of inhibition. John C. Eccles, Bernard Katz, and Stephen W. Kuffler helped to provide some of the missing links for modern neurophysiology. The current article explores several of their scientific contributions and investigates how the context of forced migration contributed to these interactions in contingently new ways.

[Mixed depressions: clinical and neurophysiological biomarkers].

PubMed

Micoulaud Franchi, J-A; Geoffroy, P-A; Vion-Dury, J; Balzani, C; Belzeaux, R; Maurel, M; Cermolacce, M; Fakra, E; Azorin, J-M

2013-12-01

Epidemiological studies of major depressive episodes (MDE) highlighted the frequent association of symptoms or signs of mania or hypomania with depressive syndrome. Beyond the strict definition of DSM-IV, epidemiological recognition of a subset of MDE characterized by the presence of symptoms or signs of the opposite polarity is clinically important because it is associated with pejorative prognosis and therapeutic response compared to the subgroup of "typical MDE". The development of DSM-5 took into account the epidemiological data. DSM-5 opted for a more dimensional perspective in implementing the concept of "mixed features" from an "episode" to a "specification" of mood disorder. As outlined in the DSM-5: "Mixed features associated with a major depressive episode have been found to be a significant risk factor for the development of bipolar I and II disorder. As a result, it is clinically useful to note the presence of this specifier for treatment planning and monitoring of response to therapeutic". However, the mixed features are sometimes difficult to identify, and neurophysiological biomarkers would be useful to make a more specific diagnosis. Two neurophysiological models make it possible to better understand MDE with mixed features : i) the emotional regulation model that highlights a tendency to hyper-reactive and unstable emotion response, and ii) the vigilance regulation model that highlights, through EEG recording, a tendency to unstable vigilance. Further research is required to better understand relationships between these two models. These models provide the opportunity of a neurophysiological framework to better understand the mixed features associated with MDE and to identify potential neurophysiological biomarkers to guide therapeutic strategies. Copyright © 2013 L’Encéphale. Published by Elsevier Masson SAS.. All rights reserved.

Neurophysiology training in the Neurology Specialist Education Program in Spain.

PubMed

Rodríguez-Antigüedad, A; Matías-Guiu, J; Hernández-Pérez, M A; Jiménez Hernández, M D; Martín González, M R; Morales Ortiz, A; Delgado, G; Frank, A; López de Silanes, C; Martínez-Vila, E

2011-06-01

The training period in neurophysiology is a substantial part of the Neurology Specialist Program in Spain. The National Neurology Committee (La Comisión Nacional de Neurología (CNN), which is the body reporting to the Ministries of Health and Education, must ensure compliance to the Program. During the first trimester of 2008, the CNN sent a questionnaire, in which there was a question asking about this training period, to each of the managers of the 69 teaching units accredited for neurology training in Spain, for them to answer. Of the 69 questionnaires issued, 49 were received completed, which was a response rate of 71%. The neurophysiology training period of the neurology specialist program in Spain was carried out in the same hospital in 44 teaching unit (90%): the remaining 5 sent their neurology trainees to 4 different hospitals. The Unit that carried out the neurophysiology training period was incorporated into the Neurology Department in 27 (55%) cases, and the formula was mixed in 3 (6%). A total of 69% of tutors were satisfied with the training, but was 90% in the hospitals where the unit was integrated into Neurology, and was 65% where this relationship did not exist. The neurologists in training were informed about EEG in 49% of education units, performed EMG/ENG 57%, and informed about evoked potentials in 35% after their training period. Although the level of satisfaction is high, the level of responsibility assumed by the neurologists in training during their rotation into neurophysiology does not appear to comply to the demands laid out in the training program, particularly in these units not integrated into Neurology Departments. Copyright © 2010 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.

Tinnitus What and Where: An Ecological Framework

PubMed Central

Searchfield, Grant D.

2014-01-01

Tinnitus is an interaction of the environment, cognition, and plasticity. The connection between the individual with tinnitus and their world seldom receives attention in neurophysiological research. As well as changes in cell excitability, an individual’s culture and beliefs, and work and social environs may all influence how tinnitus is perceived. In this review, an ecological framework for current neurophysiological evidence is considered. The model defines tinnitus as the perception of an auditory object in the absence of an acoustic event. It is hypothesized that following deafferentation: adaptive feature extraction, schema, and semantic object formation processes lead to tinnitus in a manner predicted by Adaptation Level Theory (1, 2). Evidence from physiological studies is compared to the tenants of the proposed ecological model. The consideration of diverse events within an ecological context may unite seemingly disparate neurophysiological models. PMID:25566177

Sigmund Freud and the Crick-Koch hypothesis. A footnote to the history of consciousness studies.

PubMed

Smith, D L

1999-06-01

The author describes Crick and Koch's recently developed theory of the neurophysiological basis of consciousness as synchronised neural oscillations. The thesis that neural oscillations provide the neurophysiological basis for consciousness was anticipated by Sigmund Freud in his 1895 'Project for a scientific psychology'. Freud attempted to solve his neuropsychological 'problem of quality' by means of the hypothesis that information concerning conscious sensory qualities is transmitted through the mental apparatus by means of neural 'periods'. Freud believed that information carried by neural oscillations would proliferate across 'contact-barriers' (synapses) without inhibition. Freud's theory thus appears to imply that synchronised neural oscillations are an important component of the neurophysiological basis of consciousness. It is possible that Freud's thesis was developed in response to the experimental research of the American neuroscientist M. M. Garver.

Tinnitus sensitization: a neurophysiological pathway of chronic complex tinnitus.

PubMed

Zenner, Hans P

2006-01-01

A novel neuro- and psychophysiological pathway for central cognition of tinnitus, i.e. tinnitus sensitization, is presented here. As a complement to the neurophysiological pathway for the conditioned reflex according to Jastreboff, which permits therapeutic procedures to bring about an extinction of the tinnitus (e.g. by the acoustic tinnitus retraining therapy), sensitization can be treated with procedures that act at the cognitive level. Since on the one hand therapeutic extinction procedures (e.g. the therapeutic application of sound) are still to be proven effective in controlled studies, while on the other cognitive interventions such as cognitive behavioral therapies have in fact acquired evidence level IIa in prospective studies, it is indeed appropriate to discuss whether the earlier neurophysiological model of a conditioned reflex is sufficient on its own, and whether in fact it needs to be complemented with the sensitization model.

The Postnatal Development of Spinal Sensory Processing

NASA Astrophysics Data System (ADS)

Fitzgerald, Maria; Jennings, Ernest

1999-07-01

The mechanisms by which infants and children process pain should be viewed within the context of a developing sensory nervous system. The study of the neurophysiological properties and connectivity of sensory neurons in the developing spinal cord dorsal horn of the intact postnatal rat has shed light on the way in which the newborn central nervous system analyzes cutaneous innocuous and noxious stimuli. The receptive field properties and evoked activity of newborn dorsal horn cells to single repetitive and persistent innocuous and noxious inputs are developmentally regulated and reflect the maturation of excitatory transmission within the spinal cord. These changes will have an important influence on pain processing in the postnatal period.

Critical validation studies of neurofeedback.

PubMed

Gruzelier, John; Egner, Tobias

2005-01-01

The field of neurofeedback training has proceeded largely without validation. In this article the authors review studies directed at validating sensory motor rhythm, beta and alpha-theta protocols for improving attention, memory, and music performance in healthy participants. Importantly, benefits were demonstrable with cognitive and neurophysiologic measures that were predicted on the basis of regression models of learning to enhance sensory motor rhythm and beta activity. The first evidence of operant control over the alpha-theta ratio is provided, together with remarkable improvements in artistic aspects of music performance equivalent to two class grades in conservatory students. These are initial steps in providing a much needed scientific basis to neurofeedback.

Responses to magnetic stimuli recorded in peripheral nerves in the marine nudibranch mollusk Tritonia diomedea.

PubMed

Pavlova, Galina A; Glantz, Raymon M; Dennis Willows, A O

2011-10-01

Prior behavioral and neurophysiological studies provide evidence that the nudibranch mollusk Tritonia orients to the earth's magnetic field. Earlier studies of electrophysiological responses in certain neurons of the brain to changing ambient magnetic fields suggest that although certain identified brain cells fire impulses when the ambient field is changed, these neuron somata and their central dentritic and axonal processes are themselves not primary magnetic receptors. Here, using semi-intact animal preparations from which the brain was removed, we recorded from peripheral nerve trunks. Using techniques to count spikes in individual nerves and separately also to identify, then count individual axonal spikes in extracellular records, we found both excitatory and inhibitory axonal responses elicited by changes in the direction of ambient earth strength magnetic fields. We found responses in nerves from many locations throughout the body and in axons innervating the body wall and rhinophores. Our results indicate that primary receptors for geomagnetism in Tritonia are not focally concentrated in any particular organ, but appear to be widely dispersed in the peripheral body tissues.

Computing with scale-invariant neural representations

NASA Astrophysics Data System (ADS)

Howard, Marc; Shankar, Karthik

The Weber-Fechner law is perhaps the oldest quantitative relationship in psychology. Consider the problem of the brain representing a function f (x) . Different neurons have receptive fields that support different parts of the range, such that the ith neuron has a receptive field at xi. Weber-Fechner scaling refers to the finding that the width of the receptive field scales with xi as does the difference between the centers of adjacent receptive fields. Weber-Fechner scaling is exponentially resource-conserving. Neurophysiological evidence suggests that neural representations obey Weber-Fechner scaling in the visual system and perhaps other systems as well. We describe an optimality constraint that is solved by Weber-Fechner scaling, providing an information-theoretic rationale for this principle of neural coding. Weber-Fechner scaling can be generated within a mathematical framework using the Laplace transform. Within this framework, simple computations such as translation, correlation and cross-correlation can be accomplished. This framework can in principle be extended to provide a general computational language for brain-inspired cognitive computation on scale-invariant representations. Supported by NSF PHY 1444389 and the BU Initiative for the Physics and Mathematics of Neural Systems,.

Lessons and Perspectives from a 25-Year Bioelectromagnetics Research Program

PubMed Central

Wood, Andrew W.; Lajevardipour, Alireza; McIntosh, Robert L.

2016-01-01

The question of whether electromagnetic fields from electric power or telecommunications systems can be linked unequivocally to health detriments has occupied scientific research endeavors for nearly half a century. For 25 years, the bioelectromagnetic research group at Swinburne University in Melbourne, Australia, has pursued a series of investigations with relevant endpoints, such as neurophysiological and neuropsychological effects, cell calcium level changes, proliferation, and genotoxic effects. Most have shown no significant changes due to fields, however, in some pilot studies significant changes were revealed, but in most cases these were not replicated in follow-up studies. This highlights a feature of this research area, generally; the unambiguous identification of small changes in noisy data where the understanding of possible interaction mechanisms is lacking. On the other hand, mathematical modelling studies, particularly with respect to fields near metallic implants, in workers exposed to fields in harsh environmental conditions and at very high frequencies (THz), continue to add to the expanding knowledge database on the characteristics of the complex electromagnetic environment we live in today. PMID:27669282

Synthesis, structure, luminescent, and magnetic properties of carbonato-bridged Zn(II)2Ln(III)2 complexes [(μ4-CO3)2{Zn(II)L(n)Ln(III)(NO3)}2] (Ln(III) = Gd(III), Tb(III), Dy(III); L(1) = N,N'-bis(3-methoxy-2-oxybenzylidene)-1,3-propanediaminato, L(2) = N,N'-bis(3-ethoxy-2-oxybenzylidene)-1,3-propanediaminato).

PubMed

Ehama, Kiyomi; Ohmichi, Yusuke; Sakamoto, Soichiro; Fujinami, Takeshi; Matsumoto, Naohide; Mochida, Naotaka; Ishida, Takayuki; Sunatsuki, Yukinari; Tsuchimoto, Masanobu; Re, Nazzareno

2013-11-04

Carbonato-bridged Zn(II)2Ln(III)2 complexes [(μ4-CO3)2{Zn(II)L(n)Ln(III)(NO3)}2]·solvent were synthesized through atmospheric CO2 fixation reaction of [Zn(II)L(n)(H2O)2]·xH2O, Ln(III)(NO3)3·6H2O, and triethylamine, where Ln(III) = Gd(III), Tb(III), Dy(III); L(1) = N,N'-bis(3-methoxy-2-oxybenzylidene)-1,3-propanediaminato, L(2) = N,N'-bis(3-ethoxy-2-oxybenzylidene)-1,3-propanediaminato. Each Zn(II)2Ln(III)2 structure possessing an inversion center can be described as two di-μ-phenoxo-bridged {Zn(II)L(n)Ln(III)(NO3)} binuclear units bridged by two carbonato CO3(2-) ions. The Zn(II) ion has square pyramidal coordination geometry with N2O2 donor atoms of L(n) and one oxygen atom of a bridging carbonato ion at the axial site. Ln(III) ion is coordinated by nine oxygen atoms consisting of four from the deprotonated Schiff-base L(n), two from a chelating nitrate, and three from two carbonate groups. The temperature-dependent magnetic susceptibilities in the range 1.9-300 K, field-dependent magnetization from 0 to 5 T at 1.9 K, and alternating current magnetic susceptibilities under the direct current bias fields of 0 and 1000 Oe were measured. The magnetic properties of the Zn(II)2Ln(III)2 complexes are analyzed on the basis of the dicarbonato-bridged binuclear Ln(III)-Ln(III) structure, as the Zn(II) ion with d(10) electronic configuration is diamagnetic. ZnGd1 (L(1)) and ZnGd2 (L(2)) show a ferromagnetic Gd(III)-Gd(III) interaction with J(Gd-Gd) = +0.042 and +0.028 cm(-1), respectively, on the basis of the Hamiltonian H = -2J(Gd-Gd)ŜGd1·ŜGd2. The magnetic data of the Zn(II)2Ln(III)2 complexes (Ln(III) = Tb(III), Dy(III)) were analyzed by a spin Hamiltonian including the crystal field effect on the Ln(III) ions and the Ln(III)-Ln(III) magnetic interaction. The Stark splitting of the ground state was so evaluated, and the energy pattern indicates a strong easy axis (Ising type) anisotropy. Luminescence spectra of Zn(II)2Tb(III)2 complexes were observed, while those of Zn(II)2Dy(III)2 were not detected. The fine structure assignable to the (5)D4 → (7)F6 transition of ZnTb1 and ZnTb2 is in good accord with the energy pattern from the magnetic analysis. The Zn(II)2Ln(III)2 complexes (Ln(III) = Tb(III), Dy(III)) showed an out-of-phase signal with frequency-dependence in alternating current susceptibility, indicative of single molecule magnet. Under a dc bias field of 1000 Oe, the signals become significantly more intense and the energy barrier, Δ/kB, for the magnetic relaxation was estimated from the Arrhenius plot to be 39(1) and 42(8) K for ZnTb1 and ZnTb2, and 52(2) and 67(2) K for ZnDy1 and ZnDy2, respectively.

Mammalian Toxicology Testing: Problem Definition Study, Technology Changes Impact on Testing Requirements.

DTIC Science & Technology

1981-01-01

predicted that "an enlightened attitude towards the use of personal records for research should lead to a far greater proportion of our experience being...damage in animals tested for lifetime exposure. Use of primates will expand for the validation of neurophysiological and psychological tests designed...technicians require further training. Individuals trained in neurophysiological and tissue culture techniques are also in short supply. Behavioral

Synoptic and Taxonomic Analysis of Form Perception Data and Theory.

DTIC Science & Technology

1987-11-01

project, I suggested that we may, in fact, also not be on the right road. Heavily influenced by cellular neurophysiology and conventional computer...reductionistic approach has evolved from one stressing explanations that were patently and exclusively neurophysiological to one reflecting an equal...disappointing developments associated with this new enlightenment , however valid it may be, is that we are now beginning to see some signs of limits or

Biofuels E0, E15, E85 Neurophysiology Data

EPA Pesticide Factsheets

Visual, auditory, somatosensory, and peripheral nerve evoked responses.This dataset is associated with the following publication:Herr , D., D. Freeborn , L. Degn , S.A. Martin, J. Ortenzio, L. Pantlin, C. Hamm , and W. Boyes. Neurophysiological Assessment of Auditory, Peripheral Nerve, Somatosensory, and Visual System Function After Developmental Exposure to Gasoline, E15 and E85 Vapors. NEUROTOXICOLOGY AND TERATOLOGY. Elsevier Science Ltd, New York, NY, USA, 54: 78-88, (2016).

30 CFR 850.13 - Training.

Code of Federal Regulations, 2011 CFR

2011-07-01

...; and (iii) Handling, transportation, and storage; (2) Blast designs, including— (i) Geologic and topographic considerations; (ii) Design of a blast hole, with critical dimensions; (iii) Pattern design, field... records; (9) Schedules; (10) Preblasting surveys, including— (i) Availability, (ii) Coverage, and (iii...

30 CFR 850.13 - Training.

Code of Federal Regulations, 2010 CFR

2010-07-01

...; and (iii) Handling, transportation, and storage; (2) Blast designs, including— (i) Geologic and topographic considerations; (ii) Design of a blast hole, with critical dimensions; (iii) Pattern design, field... records; (9) Schedules; (10) Preblasting surveys, including— (i) Availability, (ii) Coverage, and (iii...

30 CFR 850.13 - Training.

Code of Federal Regulations, 2012 CFR

2012-07-01

...; and (iii) Handling, transportation, and storage; (2) Blast designs, including— (i) Geologic and topographic considerations; (ii) Design of a blast hole, with critical dimensions; (iii) Pattern design, field... records; (9) Schedules; (10) Preblasting surveys, including— (i) Availability, (ii) Coverage, and (iii...

30 CFR 850.13 - Training.

Code of Federal Regulations, 2014 CFR

2014-07-01

...; and (iii) Handling, transportation, and storage; (2) Blast designs, including— (i) Geologic and topographic considerations; (ii) Design of a blast hole, with critical dimensions; (iii) Pattern design, field... records; (9) Schedules; (10) Preblasting surveys, including— (i) Availability, (ii) Coverage, and (iii...

30 CFR 850.13 - Training.

Code of Federal Regulations, 2013 CFR

2013-07-01

...; and (iii) Handling, transportation, and storage; (2) Blast designs, including— (i) Geologic and topographic considerations; (ii) Design of a blast hole, with critical dimensions; (iii) Pattern design, field... records; (9) Schedules; (10) Preblasting surveys, including— (i) Availability, (ii) Coverage, and (iii...

PLDAPS: A Hardware Architecture and Software Toolbox for Neurophysiology Requiring Complex Visual Stimuli and Online Behavioral Control.

PubMed

Eastman, Kyler M; Huk, Alexander C

2012-01-01

Neurophysiological studies in awake, behaving primates (both human and non-human) have focused with increasing scrutiny on the temporal relationship between neural signals and behaviors. Consequently, laboratories are often faced with the problem of developing experimental equipment that can support data recording with high temporal precision and also be flexible enough to accommodate a wide variety of experimental paradigms. To this end, we have developed a MATLAB toolbox that integrates several modern pieces of equipment, but still grants experimenters the flexibility of a high-level programming language. Our toolbox takes advantage of three popular and powerful technologies: the Plexon apparatus for neurophysiological recordings (Plexon, Inc., Dallas, TX, USA), a Datapixx peripheral (Vpixx Technologies, Saint-Bruno, QC, Canada) for control of analog, digital, and video input-output signals, and the Psychtoolbox MATLAB toolbox for stimulus generation (Brainard, 1997; Pelli, 1997; Kleiner et al., 2007). The PLDAPS ("Platypus") system is designed to support the study of the visual systems of awake, behaving primates during multi-electrode neurophysiological recordings, but can be easily applied to other related domains. Despite its wide range of capabilities and support for cutting-edge video displays and neural recording systems, the PLDAPS system is simple enough for someone with basic MATLAB programming skills to design their own experiments.

Measuring neurophysiological signals in aircraft pilots and car drivers for the assessment of mental workload, fatigue and drowsiness.

PubMed

Borghini, Gianluca; Astolfi, Laura; Vecchiato, Giovanni; Mattia, Donatella; Babiloni, Fabio

2014-07-01

This paper reviews published papers related to neurophysiological measurements (electroencephalography: EEG, electrooculography EOG; heart rate: HR) in pilots/drivers during their driving tasks. The aim is to summarise the main neurophysiological findings related to the measurements of pilot/driver's brain activity during drive performance and how particular aspects of this brain activity could be connected with the important concepts of "mental workload", "mental fatigue" or "situational awareness". Review of the literature suggests that exists a coherent sequence of changes for EEG, EOG and HR variables during the transition from normal drive, high mental workload and eventually mental fatigue and drowsiness. In particular, increased EEG power in theta band and a decrease in alpha band occurred in high mental workload. Successively, increased EEG power in theta as well as delta and alpha bands characterise the transition between mental workload and mental fatigue. Drowsiness is also characterised by increased blink rate and decreased HR values. The detection of such mental states is actually performed "offline" with accuracy around 90% but not online. A discussion on the possible future applications of findings provided by these neurophysiological measurements in order to improve the safety of the vehicles will be also presented. Copyright © 2012 Elsevier Ltd. All rights reserved.

Neurophysiological and Behavioral Differences between Older and Younger Adults When Processing Violations of Tonal Structure in Music

PubMed Central

Lagrois, Marie-Élaine; Peretz, Isabelle; Zendel, Benjamin Rich

2018-01-01

Aging is associated with decline in both cognitive and auditory abilities. However, evidence suggests that music perception is relatively spared, despite relying on auditory and cognitive abilities that tend to decline with age. It is therefore likely that older adults engage compensatory mechanisms which should be evident in the underlying functional neurophysiology related to processing music. In other words, the perception of musical structure would be similar or enhanced in older compared to younger adults, while the underlying functional neurophysiology would be different. The present study aimed to compare the electrophysiological brain responses of younger and older adults to melodic incongruities during a passive and active listening task. Older and younger adults had a similar ability to detect an out-of-tune incongruity (i.e., non-chromatic), while the amplitudes of the ERAN and P600 were reduced in older adults compared to younger adults. On the other hand, out-of-key incongruities (i.e., non-diatonic), were better detected by older adults compared to younger adults, while the ERAN and P600 were comparable between the two age groups. This pattern of results indicates that perception of tonal structure is preserved in older adults, despite age-related neurophysiological changes in how melodic violations are processed. PMID:29487498

Neurophysiological and Behavioral Differences between Older and Younger Adults When Processing Violations of Tonal Structure in Music.

PubMed

Lagrois, Marie-Élaine; Peretz, Isabelle; Zendel, Benjamin Rich

2018-01-01

Aging is associated with decline in both cognitive and auditory abilities. However, evidence suggests that music perception is relatively spared, despite relying on auditory and cognitive abilities that tend to decline with age. It is therefore likely that older adults engage compensatory mechanisms which should be evident in the underlying functional neurophysiology related to processing music. In other words, the perception of musical structure would be similar or enhanced in older compared to younger adults, while the underlying functional neurophysiology would be different. The present study aimed to compare the electrophysiological brain responses of younger and older adults to melodic incongruities during a passive and active listening task. Older and younger adults had a similar ability to detect an out-of-tune incongruity (i.e., non-chromatic), while the amplitudes of the ERAN and P600 were reduced in older adults compared to younger adults. On the other hand, out-of-key incongruities (i.e., non-diatonic), were better detected by older adults compared to younger adults, while the ERAN and P600 were comparable between the two age groups. This pattern of results indicates that perception of tonal structure is preserved in older adults, despite age-related neurophysiological changes in how melodic violations are processed.

The localization of facial motor impairment in sporadic Möbius syndrome.

PubMed

Cattaneo, L; Chierici, E; Bianchi, B; Sesenna, E; Pavesi, G

2006-06-27

To investigate the neurophysiologic aspects of facial motor control in patients with sporadic Möbius syndrome defined as nonprogressive congenital facial and abducens palsy. The authors assessed 24 patients with sporadic Möbius syndrome by performing a complete clinical examination and neurophysiologic tests including facial nerve conduction studies, needle electromyography examination of facial muscles, and recording of the blink reflex and of the trigeminofacial inhibitory reflex. Two distinct groups of patients were identified according to neurophysiologic testing. The first group was characterized by increased facial distal motor latencies (DMLs) and poor recruitment of small and polyphasic motor unit action potentials (MUAPs). The second group was characterized by normal facial DMLs and neuropathic MUAPs. It is hypothesized that in the first group, the disorder is due to a rhombencephalic maldevelopment with selective sparing of small-size MUs, and in the second group, the disorder is related to an acquired nervous injury during intrauterine life, with subsequent neurogenic remodeling of MUs. The trigeminofacial reflexes showed that in most subjects of both groups, the functional impairment of facial movements was caused by a nuclear or peripheral site of lesion, with little evidence of brainstem interneuronal involvement. Two different neurophysiologically defined phenotypes can be distinguished in sporadic Möbius syndrome, with different pathogenetic implications.

Regional interdependence and manual therapy directed at the thoracic spine.

PubMed

McDevitt, Amy; Young, Jodi; Mintken, Paul; Cleland, Josh

2015-07-01

Thoracic spine manipulation is commonly used by physical therapists for the management of patients with upper quarter pain syndromes. The theoretical construct for using thoracic manipulation for upper quarter conditions is a mainstay of a regional interdependence (RI) approach. The RI concept is likely much more complex and is perhaps driven by a neurophysiological response including those related to peripheral, spinal cord and supraspinal mechanisms. Recent evidence suggests that thoracic spine manipulation results in neurophysiological changes, which may lead to improved pain and outcomes in individuals with musculoskeletal disorders. The intent of this narrative review is to describe the research supporting the RI concept and its application to the treatment of individuals with neck and/or shoulder pain. Treatment utilizing both thrust and non-thrust thoracic manipulation has been shown to result in improvements in pain, range of motion and disability in patients with upper quarter conditions. Research has yet to determine optimal dosage, techniques or patient populations to which the RI approach should be applied; however, emerging evidence supporting a neurophysiological effect for thoracic spine manipulation may negate the need to fully answer this question. Certainly, there is a need for further research examining both the clinical efficacy and effectiveness of manual therapy interventions utilized in the RI model as well as the neurophysiological effects resulting from this intervention.

Memory formation during anaesthesia: plausibility of a neurophysiological basis.

PubMed

Veselis, R A

2015-07-01

As opposed to conscious, personally relevant (explicit) memories that we can recall at will, implicit (unconscious) memories are prototypical of 'hidden' memory; memories that exist, but that we do not know we possess. Nevertheless, our behaviour can be affected by these memories; in fact, these memories allow us to function in an ever-changing world. It is still unclear from behavioural studies whether similar memories can be formed during anaesthesia. Thus, a relevant question is whether implicit memory formation is a realistic possibility during anaesthesia, considering the underlying neurophysiology. A different conceptualization of memory taxonomy is presented, the serial parallel independent model of Tulving, which focuses on dynamic information processing with interactions among different memory systems rather than static classification of different types of memories. The neurophysiological basis for subliminal information processing is considered in the context of brain function as embodied in network interactions. Function of sensory cortices and thalamic activity during anaesthesia are reviewed. The role of sensory and perisensory cortices, in particular the auditory cortex, in support of memory function is discussed. Although improbable, with the current knowledge of neurophysiology one cannot rule out the possibility of memory formation during anaesthesia. © The Author 2015. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Pain neurophysiology education improves cognitions, pain thresholds, and movement performance in people with chronic whiplash: a pilot study.

PubMed

Van Oosterwijck, Jessica; Nijs, Jo; Meeus, Mira; Truijen, Steven; Craps, Julie; Van den Keybus, Nick; Paul, Lorna

2011-01-01

Chronic whiplash is a debilitating condition characterized by increased sensitivity to painful stimuli, maladaptive illness beliefs, inappropriate attitudes, and movement dysfunctions. Previous work in people with chronic low back pain and chronic fatigue syndrome indicates that pain neurophysiology education is able to improve illness beliefs and attitudes as well as movement performance. This single-case study (A-B-C design) with six patients with chronic whiplash associated disorders (WAD) was aimed at examining whether education about the neurophysiology of pain is accompanied by changes in symptoms, daily functioning, pain beliefs, and behavior. Periods A and C represented assessment periods, while period B consisted of the intervention (pain neurophysiology education). Results showed a significant decrease in kinesiophobia (Tampa Scale for Kinesiophobia), the passive coping strategy of resting (Pain Coping Inventory), self-rated disability (Neck Disability Index), and photophobia (WAD Symptom List). At the same time, significantly increased pain pressure thresholds and improved pain-free movement performance (visual analog scale on Neck Extension Test and Brachial Plexus Provocation Test) were established. Although the current results need to be verified in a randomized, controlled trial, they suggest that education about the physiology of pain is able to increase pain thresholds and improve pain behavior and pain-free movement performance in patients with chronic WAD.

[Towards a new approach of neurophysiology in clinical psychiatry: functional magnetic resonance imaging neurofeedback applied to emotional dysfunctions].

PubMed

Micoulaud-Franchi, J-A; Fakra, E; Cermolacce, M; Vion-Dury, J

2012-04-01

Emotions color in a singular way our everyday life and constitute important determinants of human cognition and behavior. Emotional regulation is an essential process involved in neuropathophysiology and therapeutic efficacy in many psychiatric disorders. Yet, traditional psychiatric therapeutic has focused on symptomatic rather than neurophysiological criteria. Therefore, it was proposed to teach patients to modify their own brain activity directly, in order to obtain a therapeutic effect. These techniques, which are named neurofeedback, were originally developed using electroencephalography. Recent technical advances in fMRI enable real-time acquisition, and open opportunities to its utilization in neurofeedback. This seems particularly interesting in emotion regulation, which, at a neurofunctional level, lies on cortico-limbic pathways that, in great parts, were previously identified by traditional fMRI paradigms. This emotion regulation plays a central role in the etiopathogeny psychiatric, especially depressive and anxious, disorders. It is possible to devise new therapeutic strategies and research approach for addressing directly the neurophysiological processes of emotion regulation by integrating the neurofunctional activities of a subject. These prospects seem to be in line with the neurophenomenology project, which proposes to establish a link between subjective experiences and objective neurophysiological measures. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Field and laboratory evidence for intrinsic biodegradation of vinyl chloride contamination in a Fe(III)-reducing aquifer

USGS Publications Warehouse

Bradley, P.M.; Chapelle, F.H.; Wilson, J.T.

1998-01-01

Intrinsic bioremediation of chlorinated ethenes in anaerobic aquifers previously has not been considered feasible, due, in large part, to 1) the production of vinyl chloride during microbial reductive dechlorination of higher chlorinated contaminants and 2) the apparent poor biodegradability of vinyl chloride under anaerobic conditions. In this study, a combination of field geochemical analyses and laboratory radiotracer ([1,2-14C] vinyl chloride) experiments was utilized to assess the potential for intrinsic biodegradation of vinyl chloride contamination in an Fe(III)-reducing, anaerobic aquifer. Microcosm experiments conducted under Fe(III)-reducing conditions with material from the Fe(III)-reducing, chlorinated-ethene contaminated aquifer demonstrated significant oxidation of [1,2-14C] vinyl chloride to 14CO2 with no detectable production of ethene or other reductive dehalogenation products. Rates of degradation derived from the microcosm experiments (0.9-1.3% d-1) were consistent with field-estimated rates (0.03-0.2% d-1) of apparent vinyl chloride degradation. Field estimates of apparent vinyl chloride biodegradation were calculated using two distinct approaches; 1) a solute dispersion model and 2) a mass balance assessment. These findings demonstrate that degradation under Fe(III) reducing conditions can be an environmentally significant mechanism for intrinsic bioremediation of vinyl chloride in anaerobic ground-water systems.

Field Operations and Enforcement Manual for Air Pollution Control. Volume III: Inspection Procedures for Specific Industries.

ERIC Educational Resources Information Center

Weisburd, Melvin I.

The Field Operations and Enforcement Manual for Air Pollution Control, Volume III, explains in detail the following: inspection procedures for specific sources, kraft pulp mills, animal rendering, steel mill furnaces, coking operations, petroleum refineries, chemical plants, non-ferrous smelting and refining, foundries, cement plants, aluminum…

Magnetic properties of Fe-doped organic-inorganic nanohybrids

NASA Astrophysics Data System (ADS)

Silva, N. J. O.; Amaral, V. S.; Carlos, L. D.; de Zea Bermudez, V.

2003-05-01

We present a magnetic study of Fe-doped diureasils (siloxane-based networks to which poly(ethylene oxide)-based chains are grafted by urea cross linkages doped with Fe(II) or Fe(III) ions. Structural studies show that the Fe(II) ions interact mainly with the organic chain, whereas the incorporation of Fe(III) leads to the formation of iron-based nanoclusters, with radius increasing from 20 to 40 Å. Fe(II)-doped samples behave as simple paramagnets, with μeff=5.32μB. Fe(III)-doped hybrids present antiferromagnetic interactions, with TN increasing with Fe(III) concentration up to 13.6 K for 6% doping. Thermal irreversibility was observed below ˜40 K and is stronger for higher concentrations. The coercive fields (HC) are of the order of 1000 Oe at 5 K. Hysteresis cycles are shifted to negative fields, revealing the presence of exchange anisotropy interactions with exchange fields (HE) of the order of 100 Oe. Both fields decrease rapidly with increasing temperature. We analyze this behavior in terms of the contribution of surface spin disorder to exchange anisotropy.

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; arsenic speciation in natural-water samples using laboratory and field methods

USGS Publications Warehouse

Garbarino, John R.; Bednar, Anthony J.; Burkhardt, Mark R.

2002-01-01

Analytical methods for the determination of arsenite [As(III)], arsenate [As(V)], dimethylarsinate (DMA), monomethylarsonate (MMA), and roxarsone in filtered natural-water samples are described. Various analytical methods can be used for the determination, depending on the arsenic species being determined. Arsenic concentration is determined by using inductively coupled plasma-mass spectrometry (ICP-MS) as an arsenic-specific detector for all methods. Laboratory-speciation methods are described that use an ion chromatographic column to separate the arsenic species; the column length, column packing, and mobile phase are dependent on the species of interest. Regardless of the separation technique, the arsenic species are introduced into plasma by eithe rpneumatic nebulization or arsine generation. Analysis times range from 2 to 8 minutes and method detection limits range from 0.1 to 0.6 microgram-arsenic per liter (ug-As/L), 10 to 60 picograms absolute (for a 100-microliter injection), depending on the arsenic species determined and the analytical method used. A field-generation specciation method also is described that uses a strong anion exchange cartridge to separate As(III) from As(V) in the field. As(III) in the eluate and the As(V) in the cartridge extract are determined by direct nebulization ICP-MS. Methylated arsenic species that also are retained on the cartridge will positively bias As(V) results without further laboratory separations. The method detection limit for field speciation is 0.3 ug-As/L. The distribution of arsenic species must be preserved in the field to eliminate changes caused by photochemical oxidation or metal oxyhydroxide precipitation. Preservation techniques, such as refrigeration, the addition of acides, or the additoin of ethylene-diaminetetraacetic acid (EDTA) and the effects of ambient light were tested. Of the preservatives evaluated, EDTA was found to work best with the laboratory- and field-speciation methods for all sample matrices tested. Storing the samples in opaque polytethylene bottles eliminated the effects of photochemical oxidation. The percentage change in As(III):As(V) ratios for an EDTA-preserved acid mine drainage (AMD) sample and ground-water sample during a 3-month period was -5 percent and +3 percent, respectively. The bias and variability of the methods were evaluated by comparing results for total arsenic and As(III), As(V), DMA, and MMA concentrations in ground water, AMD, and surface water. Seventy-one ground-water, 10 AMD, and 24 surface-water samples were analyzed. Concentrations in ground-water samples reached 720 ug-As/L for As(III) and 1080 ug-As/L for As(V); AMD samples reached 12800 ug-As/L for As(III) and 7050 ug-As/L for As(V); and surface-water samples reached 5 ug-As/L for As(III) and As(V). Inorganic arsenic species distribution in the samples ranged from 0 to 90 percent As(III). DMA and MMA were present only in surface-water samples from agricultural areas where the herbicide monosodium methylarsonate was applied; concentrations never exceeded 6 ug-As/L. Statistical analyses indicated that the difference between As(III) and As(V) concentrations for samples preserved with EDTA in opaque bottles and field-speciation results were analytically insignificant at the 95-percent confidence interval. There was no significant difference among the methods tested for total arsenic concentration. Percentage recovery for field samples spiked at 50 ug-As/L and analyzed by the laboratory-speciation method (n=2) ranged from 82 to 100 percent for As(III), 97 to 102 percent for As(V), 90 to 104 percent for DMA, and 81 to 96 percent for MMA; recoveries for samples spiked at 100 ug-As/L and analyzed by the field-speciation method ranged from 102 to 107 percent for As(III) and 105 to 106 percent for As(V). Laboratory-speciation results for Environment Canada reference material SLRS-2 closely matched reported concentrations. Laboratory-speciation metho

Neurophysiological Pathways to Obesity: Below Awareness and Beyond Individual Control

PubMed Central

Cohen, Deborah A.

2008-01-01

A global obesity epidemic is occurring simultaneously with ongoing increases in the availability and salience of food in the environment. Obesity is increasing across all socioeconomic groups and educational levels and occurs even among individuals with the highest levels of education and expertise in nutrition and related fields. Given these circumstances, it is plausible that excessive food consumption occurs in ways that defy personal insight or are below individual awareness. The current food environment stimulates automatic reflexive responses that enhance the desire to eat and increase caloric intake, making it exceedingly difficult for individuals to resist, especially because they may not be aware of these influences. This article identifies 10 neurophysiological pathways that can lead people to make food choices subconsciously or, in some cases, automatically. These pathways include reflexive and uncontrollable neurohormonal responses to food images, cues, and smells; mirror neurons that cause people to imitate the eating behavior of others without awareness; and limited cognitive capacity to make informed decisions about food. Given that people have limited ability to shape the food environment individually and no ability to control automatic responses to food-related cues that are unconsciously perceived, it is incumbent upon society as a whole to regulate the food environment, including the number and types of food-related cues, portion sizes, food availability, and food advertising. PMID:18586908

Reference-Free Removal of EEG-fMRI Ballistocardiogram Artifacts with Harmonic Regression

PubMed Central

Krishnaswamy, Pavitra; Bonmassar, Giorgio; Poulsen, Catherine; Pierce, Eric T; Purdon, Patrick L.; Brown, Emery N.

2016-01-01

Combining electroencephalogram (EEG) recording and functional magnetic resonance imaging (fMRI) offers the potential for imaging brain activity with high spatial and temporal resolution. This potential remains limited by the significant ballistocardiogram (BCG) artifacts induced in the EEG by cardiac pulsation-related head movement within the magnetic field. We model the BCG artifact using a harmonic basis, pose the artifact removal problem as a local harmonic regression analysis, and develop an efficient maximum likelihood algorithm to estimate and remove BCG artifacts. Our analysis paradigm accounts for time-frequency overlap between the BCG artifacts and neurophysiologic EEG signals, and tracks the spatiotemporal variations in both the artifact and the signal. We evaluate performance on: simulated oscillatory and evoked responses constructed with realistic artifacts; actual anesthesia-induced oscillatory recordings; and actual visual evoked potential recordings. In each case, the local harmonic regression analysis effectively removes the BCG artifacts, and recovers the neurophysiologic EEG signals. We further show that our algorithm outperforms commonly used reference-based and component analysis techniques, particularly in low SNR conditions, the presence of significant time-frequency overlap between the artifact and the signal, and/or large spatiotemporal variations in the BCG. Because our algorithm does not require reference signals and has low computational complexity, it offers a practical tool for removing BCG artifacts from EEG data recorded in combination with fMRI. PMID:26151100

Transcranial magnetic stimulation in developmental stuttering: Relations with previous neurophysiological research and future perspectives.

PubMed

Busan, P; Battaglini, P P; Sommer, M

2017-06-01

Developmental stuttering (DS) is a disruption of the rhythm of speech, and affected people may be unable to execute fluent voluntary speech. There are still questions about the exact causes of DS. Evidence suggests there are differences in the structure and functioning of motor systems used for preparing, executing, and controlling motor acts, especially when they are speech related. Much research has been obtained using neuroimaging methods, ranging from functional magnetic resonance to diffusion tensor imaging and electroencephalography/magnetoencephalography. Studies using transcranial magnetic stimulation (TMS) in DS have been uncommon until recently. This is surprising considering the relationship between the functionality of the motor system and DS, and the wide use of TMS in motor-related disturbances such as Parkinson's Disease, Tourette's Syndrome, and dystonia. Consequently, TMS could shed further light on motor aspects of DS. The present work aims to investigate the use of TMS for understanding DS neural mechanisms by reviewing TMS papers in the DS field. Until now, TMS has contributed to the understanding of the excitatory/inhibitory ratio of DS motor functioning, also helping to better understand and critically review evidence about stuttering mechanisms obtained from different techniques, which allowed the investigation of cortico-basal-thalamo-cortical and white matter/connection dysfunctions. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

A Brain-Machine-Brain Interface for Rewiring of Cortical Circuitry after Traumatic Brain Injury

DTIC Science & Technology

2013-09-01

were requested to provide further evidence, either neurophysiological or neuroanatomical, of enhanced connectivity (no additional studies in new...report. The algorithms developed during the course of the manuscript revision have proved to be very enlightening . During Year 3, we revisited our Year...to our local IACUC and subsequently, to ACURO during Year 4. As a result of the Nature reviews, we focused on a more neurophysiological approach to

The neurophysiology of sexual arousal.

PubMed

Schober, Justine M; Pfaff, Donald

2007-09-01

Our understanding of the process and initiation of sexual arousal is being enhanced by both animal and human studies, inclusive of basic science principles and research on clinical outcomes. Sexual arousal is dependent on neural (sensory and cognitive) factors, hormonal factors, genetic factors and, in the human case, the complex influences of culture and context. Sexual arousal activates the cognitive and physiologic processes that can eventually lead to sexual behavior. Sexual arousal comprises a particular subset of central nervous system arousal functions which depend on primitive, fundamental arousal mechanisms that cause generalized brain activity, but are manifest in a sociosexual context. The neurophysiology of sexual arousal is seen as a bidirectional system universal to all vertebrates. The following review includes known neural and genomic mechanisms of a hormone-dependent circuit for simple sex behavior. New information about hormone effects on causal steps related to sex hormones' nuclear receptor isoforms expressed by hypothalamic neurons continues to enrich our understanding of this neurophysiology.

Severe peripheral neuropathy and elevated plantar pressures causing foot ulceration in pituitary gigantism.

PubMed

Jennings, A M; Robinson, A; Kandler, R H; Betts, R P; Ryder, R E; Cullen, D R

1993-07-01

We report two patients with treated pituitary gigantism and peripheral neuropathy, one of whom has chronic foot ulceration. Detailed neurophysiological assessment was performed on both patients. The patient with foot ulceration had clinical and neurophysiological evidence of severe neuropathy, whereas the patient without ulceration had only neurophysiological abnormalities. The sweating response to acetylcholine was markedly impaired in the feet of both patients, suggesting pedal autonomic denervation. Neither patient had evidence of diabetes mellitus and detailed investigation failed to reveal an alternative cause of peripheral neuropathy. Optical pedobarography revealed abnormally high pressure (> 10 kg/cm2) under the metatarsal heads of both patients, one such area coinciding with the area of ulceration. Thus in pituitary gigantism elevated plantar pressures may contribute to the development of foot ulceration when severe peripheral neuropathy is present. Furthermore, as in diabetes mellitus, impaired sweating may also increase the risk of ulceration as the resultant dry skin may develop fissures.

Assessing fitness-for-duty and predicting performance with cognitive neurophysiological measures

NASA Astrophysics Data System (ADS)

Smith, Michael E.; Gevins, Alan

2005-05-01

Progress is described in developing a novel test of neurocognitive status for fitness-for-duty testing. The Sustained Attention & Memory (SAM) test combines neurophysiologic (EEG) measures of brain activation with performance measures during a psychometric test of sustained attention and working memory, and then gauges changes in neurocognitive status relative to an individual"s normative baseline. In studies of the effects of common psychoactive substances that can affect job performance, including sedating antihistamines, caffeine, alcohol, marijuana, and prescription medications, test sensitivity was greater for the combined neurophysiological and performance measures than for task performance measures by themselves. The neurocognitive effects of overnight sleep deprivation were quite evident, and such effects predicted subsequent performance impairment on a flight simulator task. Sensitivity to diurnal circadian variations was also demonstrated. With further refinement and independent validation, the SAM Test may prove useful for assessing readiness-to-perform in high-asset personnel working in demanding, high risk situations.

Quantitative EEG reflects non-dopaminergic disease severity in Parkinson's disease.

PubMed

Geraedts, Victor J; Marinus, Johan; Gouw, Alida A; Mosch, Arne; Stam, Cornelis J; van Hilten, Jacobus J; Contarino, Maria Fiorella; Tannemaat, Martijn R

2018-05-29

In Parkinson's Disease (PD), measures of non-dopaminergic systems involvement may reflect disease severity and therefore contribute to patient-selection for Deep Brain Stimulation (DBS). There is currently no determinant for non-dopaminergic disease severity. In this exploratory study, we investigated whether quantitative EEG reflects non-dopaminergic disease severity in PD. Sixty-three consecutive PD patients screened for DBS were included (mean age 62.4 ± 7.2 years, 32% females). Relative spectral powers and the Phase-Lag-Index (PLI) reflecting functional connectivity were analysed on routine EEGs. Non-dopaminergic disease severity was quantified using the SENS-PD score and its subdomains; motor-severity was quantified using the MDS-UPDRS III. The SENS-PD composite score correlated with a spectral ratio ((δ + θ)/(α1 + α2 + β) powers) (global spectral ratio Pearson's r = 0.4, 95% Confidence Interval (95%CI) 0.1-0.6), and PLI in the α2 band (10-13 Hz) (r = -0.3, 95%CI -0.5 to -0.1). These correlations seem driven by the subdomains cognition and psychotic symptoms. MDS-UPDRS III was not significantly correlated with EEG parameters. EEG slowing and reduced functional connectivity in the α2 band were associated with non-dopaminergic disease severity in PD. The described EEG parameters may have complementary utility as determinants of non-dopaminergic involvement in PD. Copyright © 2018 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Preservation of water samples for arsenic(III/V) determinations: An evaluation of the literature and new analytical results

USGS Publications Warehouse

McCleskey, R. Blaine; Nordstrom, D. Kirk; Maest, A.S.

2004-01-01

Published literature on preservation procedures for stabilizing aqueous inorganic As(III/V) redox species contains discrepancies. This study critically evaluates published reports on As redox preservation and explains discrepancies in the literature. Synthetic laboratory preservation experiments and time stability experiments were conducted for natural water samples from several field sites. Any field collection procedure that filters out microorganisms, adds a reagent that prevents dissolved Fe and Mn oxidation and precipitation, and isolates the sample from solar radiation will preserve the As(III/V) ratio. Reagents that prevent Fe and Mn oxidation and precipitation include HCl, H 2SO4, and EDTA, although extremely high concentrations of EDTA are necessary for some water samples high in Fe. Photo-catalyzed Fe(III) reduction causes As(III) oxidation; however, storing the sample in the dark prevents photochemical reactions. Furthermore, the presence of Fe(II) or SO 4 inhibits the oxidation of As(III) by Fe(III) because of complexation reactions and competing reactions with free radicals. Consequently, fast abiotic As(III) oxidation reactions observed in the laboratory are not observed in natural water samples for one or more of the following reasons: (1) the As redox species have already stabilized, (2) most natural waters contain very low dissolved Fe(III) concentrations, (3) the As(III) oxidation caused by Fe(III) photoreduction is inhibited by Fe(II) or SO4.

Installation Restoration Program (IRP) Site Investigation Report for IRP Site Number 4. Volume 3. Appendices D-I. 128th Air Refueling Wing, Wisconsin Air National Guard, General Billy Mitchell Field Air National Guard Base, Milwaukee, Wisconsin.

DTIC Science & Technology

1996-03-01

NATIONAL GUARD GENERAL BILLY MITCHELL FIELD AIR NATIONAL GUARD BASE MILWAUKEE, WISCONSIN MARCH 1996 ______ 19960509 134 HQ ANG/CEVR ANDREWS AFB...Report for IRP Site No. 4, Wisconsin Air National Guard, 128th Air Refueling Wing, General Billy Mitchell Field, Milwaukee, Wisconsin - Volume III...Wisconsin Air National Guard, 128th Air Refueling Wing, General Billy Mitchell Field, Milwaukee, Wisconsin, Volume III - Appendices D-I. This is the

Rapid tuning shifts in human auditory cortex enhance speech intelligibility

PubMed Central

Holdgraf, Christopher R.; de Heer, Wendy; Pasley, Brian; Rieger, Jochem; Crone, Nathan; Lin, Jack J.; Knight, Robert T.; Theunissen, Frédéric E.

2016-01-01

Experience shapes our perception of the world on a moment-to-moment basis. This robust perceptual effect of experience parallels a change in the neural representation of stimulus features, though the nature of this representation and its plasticity are not well-understood. Spectrotemporal receptive field (STRF) mapping describes the neural response to acoustic features, and has been used to study contextual effects on auditory receptive fields in animal models. We performed a STRF plasticity analysis on electrophysiological data from recordings obtained directly from the human auditory cortex. Here, we report rapid, automatic plasticity of the spectrotemporal response of recorded neural ensembles, driven by previous experience with acoustic and linguistic information, and with a neurophysiological effect in the sub-second range. This plasticity reflects increased sensitivity to spectrotemporal features, enhancing the extraction of more speech-like features from a degraded stimulus and providing the physiological basis for the observed ‘perceptual enhancement' in understanding speech. PMID:27996965

Human brain networks function in connectome-specific harmonic waves.

PubMed

Atasoy, Selen; Donnelly, Isaac; Pearson, Joel

2016-01-21

A key characteristic of human brain activity is coherent, spatially distributed oscillations forming behaviour-dependent brain networks. However, a fundamental principle underlying these networks remains unknown. Here we report that functional networks of the human brain are predicted by harmonic patterns, ubiquitous throughout nature, steered by the anatomy of the human cerebral cortex, the human connectome. We introduce a new technique extending the Fourier basis to the human connectome. In this new frequency-specific representation of cortical activity, that we call 'connectome harmonics', oscillatory networks of the human brain at rest match harmonic wave patterns of certain frequencies. We demonstrate a neural mechanism behind the self-organization of connectome harmonics with a continuous neural field model of excitatory-inhibitory interactions on the connectome. Remarkably, the critical relation between the neural field patterns and the delicate excitation-inhibition balance fits the neurophysiological changes observed during the loss and recovery of consciousness.

Neurophysiological mechanisms of cortical plasticity impairments in schizophrenia and modulation by the NMDA receptor agonist D-serine.

PubMed

Kantrowitz, Joshua T; Epstein, Michael L; Beggel, Odeta; Rohrig, Stephanie; Lehrfeld, Jonathan M; Revheim, Nadine; Lehrfeld, Nayla P; Reep, Jacob; Parker, Emily; Silipo, Gail; Ahissar, Merav; Javitt, Daniel C

2016-12-01

Schizophrenia is associated with deficits in cortical plasticity that affect sensory brain regions and lead to impaired cognitive performance. Here we examined underlying neural mechanisms of auditory plasticity deficits using combined behavioural and neurophysiological assessment, along with neuropharmacological manipulation targeted at the N-methyl-D-aspartate type glutamate receptor (NMDAR). Cortical plasticity was assessed in a cohort of 40 schizophrenia/schizoaffective patients relative to 42 healthy control subjects using a fixed reference tone auditory plasticity task. In a second cohort (n = 21 schizophrenia/schizoaffective patients, n = 13 healthy controls), event-related potential and event-related time-frequency measures of auditory dysfunction were assessed during administration of the NMDAR agonist d-serine. Mismatch negativity was used as a functional read-out of auditory-level function. Clinical trials registration numbers were NCT01474395/NCT02156908 Schizophrenia/schizoaffective patients showed significantly reduced auditory plasticity versus healthy controls (P = 0.001) that correlated with measures of cognitive, occupational and social dysfunction. In event-related potential/time-frequency analyses, patients showed highly significant reductions in sensory N1 that reflected underlying impairments in θ responses (P < 0.001), along with reduced θ and β-power modulation during retention and motor-preparation intervals. Repeated administration of d-serine led to intercorrelated improvements in (i) auditory plasticity (P < 0.001); (ii) θ-frequency response (P < 0.05); and (iii) mismatch negativity generation to trained versus untrained tones (P = 0.02). Schizophrenia/schizoaffective patients show highly significant deficits in auditory plasticity that contribute to cognitive, occupational and social dysfunction. d-serine studies suggest first that NMDAR dysfunction may contribute to underlying cortical plasticity deficits and, second, that repeated NMDAR agonist administration may enhance cortical plasticity in schizophrenia. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Structural and Functional Correlates of Visual Field Asymmetry in the Human Brain by Diffusion Kurtosis MRI and Functional MRI

PubMed Central

O’Connell, Caitlin; Ho, Leon C.; Murphy, Matthew C.; Conner, Ian P.; Wollstein, Gadi; Cham, Rakie; Chan, Kevin C.

2016-01-01

Human visual performance has been observed to exhibit superiority in localized regions of the visual field across many classes of stimuli. However, the underlying neural mechanisms remain unclear. This study aims to determine if the visual information processing in the human brain is dependent on the location of stimuli in the visual field and the corresponding neuroarchitecture using blood-oxygenation-level-dependent functional MRI (fMRI) and diffusion kurtosis MRI (DKI), respectively in 15 healthy individuals at 3 Tesla. In fMRI, visual stimulation to the lower hemifield showed stronger brain responses and larger brain activation volumes than the upper hemifield, indicative of the differential sensitivity of the human brain across the visual field. In DKI, the brain regions mapping to the lower visual field exhibited higher mean kurtosis but not fractional anisotropy or mean diffusivity when compared to the upper visual field. These results suggested the different distributions of microstructural organization across visual field brain representations. There was also a strong positive relationship between diffusion kurtosis and fMRI responses in the lower field brain representations. In summary, this study suggested the structural and functional brain involvements in the asymmetry of visual field responses in humans, and is important to the neurophysiological and psychological understanding of human visual information processing. PMID:27631541

Magnetoviscoelastic characteristics of superparamagnetic oxides (Fe, Ni) based ferrofluids

NASA Astrophysics Data System (ADS)

Katiyar, Ajay; Dhar, Purbarun; Nandi, Tandra; Das, Sarit K.

2017-08-01

Ferrofluids have been popular among the academic and scientific communities owing to their intelligent physical characteristics under external stimuli and are in fact among the first nanotechnology products to be employed in real world applications. However, studies on the magnetoviscoelastic behavior of concentrated ferrofluids, especially of superparamagnetic oxides of iron and nickel are rare. The present article comprises the formulation of magneto-colloids utilizing the three various metal oxides nanoparticles viz. Iron (II, III) oxide (Fe3O4), Iron (III) oxide (Fe2O3) and Nickel oxide (NiO) in oil. Iron (II, III) oxide based colloids demonstrate high magnetoviscous characteristics over the other oxides based colloids under external magnetic fields. The maximum magnitude of yield stress and viscosity is found to be 3.0 kPa and 2.9 kPa.s, respectively for iron (II, III) oxide based colloids at 2.6 vol% particle concentration and 1.2 T magnetic field. Experimental investigations reveal that the formulated magneto-nanocolloids are stable, even in high magnetic fields and almost reversible when exposed to rising and drop of magnetic fields of the same magnitude. Observations also reveal that the elastic behavior dominates over the viscous behavior with enhanced relaxation and creep characteristics under the magnetic field. The effect of temperature on viscosity and yield stress of magneto-nanocolloids under magnetic fields has also been discussed. Thus, the present findings have potential applications in various fields such as electromagnetic clutch and brakes of automotive, damping, sealing, optics, nanofinishing etc.

The entorhinal cortex of the Megachiroptera: a comparative study of Wahlberg's epauletted fruit bat and the straw-coloured fruit bat.

PubMed

Gatome, Catherine W; Slomianka, Lutz; Mwangi, Dieter K; Lipp, Hans-Peter; Amrein, Irmgard

2010-05-01

This study describes the organisation of the entorhinal cortex of the Megachiroptera, straw-coloured fruit bat and Wahlberg's epauletted fruit bat. Using Nissl and Timm stains, parvalbumin and SMI-32 immunohistochemistry, we identified five fields within the medial (MEA) and lateral (LEA) entorhinal areas. MEA fields E(CL) and E(C) are characterised by a poor differentiation between layers II and III, a distinct layer IV and broad, stratified layers V and VI. LEA fields E(I), E(R) and E(L) are distinguished by cell clusters in layer II, a clear differentiation between layers II and III, a wide columnar layer III and a broad sublayer Va. Clustering in LEA layer II was more typical of the straw-coloured fruit bat. Timm-staining was most intense in layers Ib and II across all fields and layer III of field E(R). Parvalbumin-like staining varied along a medio-lateral gradient with highest immunoreactivity in layers II and III of MEA and more lateral fields of LEA. Sparse SMI-32-like immunoreactivity was seen only in Wahlberg's epauletted fruit bat. Of the neurons in MEA layer II, ovoid stellate cells account for approximately 38%, polygonal stellate cells for approximately 8%, pyramidal cells for approximately 18%, oblique pyramidal cells for approximately 6% and other neurons of variable morphology for approximately 29%. Differences between bats and other species in cellular make-up and cytoarchitecture of layer II may relate to their three-dimensional habitat. Cytoarchitecture of layer V in conjunction with high encephalisation and structural changes in the hippocampus suggest similarities in efferent hippocampal --> entorhinal --> cortical interactions between fruit bats and primates.

Neurophysiological correlates of altered response inhibition in internet gaming disorder and obsessive-compulsive disorder: Perspectives from impulsivity and compulsivity

PubMed Central

Kim, Minah; Lee, Tak Hyung; Choi, Jung-Seok; Kwak, Yoo Bin; Hwang, Wu Jeong; Kim, Taekwan; Lee, Ji Yoon; Lim, Jae-A; Park, Minkyung; Kim, Yeon Jin; Kim, Sung Nyun; Kim, Dai Jin; Kwon, Jun Soo

2017-01-01

Although internet gaming disorder (IGD) and obsessive-compulsive disorder (OCD) represent opposite ends of the impulsivity and compulsivity dimensions, the two disorders share common neurocognitive deficits in response inhibition. However, the similarities and differences in neurophysiological features of altered response inhibition between IGD and OCD have not been investigated sufficiently. In total, 27 patients with IGD, 24 patients with OCD, and 26 healthy control (HC) subjects participated in a Go/NoGo task with electroencephalographic recordings. N2-P3 complexes elicited during Go and NoGo condition were analyzed separately and compared among conditions and groups. NoGo-N2 latency at the central electrode site was delayed in IGD group versus the HC group and correlated positively with the severity of internet game addiction and impulsivity. NoGo-N2 amplitude at the frontal electrode site was smaller in OCD patients than in IGD patients. These findings suggest that prolonged NoGo-N2 latency may serve as a marker of trait impulsivity in IGD and reduced NoGo-N2 amplitude may be a differential neurophysiological feature between OCD from IGD with regard to compulsivity. We report the first differential neurophysiological correlate of the altered response inhibition in IGD and OCD, which may be a candidate biomarker for impulsivity and compulsivity. PMID:28134318

Multimodal neurophysiological and psychometric evaluation among patients with systemic lupus erythematosus

PubMed Central

Shehata, Ghaydaa A; Elserogy, Yasser MB; Ahmad, Hossam Eddin K; Abdel-Kareem, Mohamed I; Al-kabeer, Ashraf M; Rayan, Mohamed M; El-Baky, Mohamed ES Abd

2011-01-01

Objective: To determine some of the neuropsychiatric manifestations of systemic lupus erythematosus (SLE) by applying multimodal neurophysiological and psychometric studies. Patients and methods: Twenty-six SLE patients were evaluated for neurological and psychiatric disorders and compared with 26 healthy controls matched for age, sex, education, and social class. The severity of SLE disease was assessed. Each subject was subjected to the following examinations: laboratory, neurophysiology, magnetic resonance imaging of the brain, transcranial duplex, Modified Mini-mental State Examination, Cognitive Assessment Scale Inventory, Hamilton Depression Scale, and Hamilton Anxiety Scale. Results: The mean age of subjects was 25.9 ± 8.9 years. The most prevalent neurological manifestations were (in order of frequency) anxiety in 17 cases (65.4%), depression in 15 cases (57.7%), headache in 10 cases (38.5%), peripheral neuropathy in 7 cases (26.9%), seizures in 6 cases (23.1%), psychosis in 5 cases (19.2%), dementia in 4 cases (15.4%), radiculopathy in 4 cases (15.4%), myositis in 3 cases (11.5%), and stroke in 2 cases (7.7%). There was a significant affection in amplitude of the ulnar nerve, cognitive function impairment, and electroencephalography changes. There was a significant increased mean velocity and decreased Pulsatility Index of the most studied intracranial vessels in the patients. Conclusion: The use of multimodal neurophysiological, transcranial duplex, and psychometric scales increases the sensitivity for detecting nervous system involvement. PMID:21674025

Neurophysiological correlates of word processing deficits in isolated reading and isolated spelling disorders.

PubMed

Bakos, Sarolta; Landerl, Karin; Bartling, Jürgen; Schulte-Körne, Gerd; Moll, Kristina

2018-03-01

In consistent orthographies, isolated reading disorders (iRD) and isolated spelling disorders (iSD) are nearly as common as combined reading-spelling disorders (cRSD). However, the exact nature of the underlying word processing deficits in isolated versus combined literacy deficits are not well understood yet. We applied a phonological lexical decision task (including words, pseudohomophones, legal and illegal pseudowords) during ERP recording to investigate the neurophysiological correlates of lexical and sublexical word-processing in children with iRD, iSD and cRSD compared to typically developing (TD) 9-year-olds. TD children showed enhanced early sensitivity (N170) for word material and for the violation of orthographic rules compared to the other groups. Lexical orthographic effects (higher LPC amplitude for words than for pseudohomophones) were the same in the TD and iRD groups, although processing took longer in children with iRD. In the iSD and cRSD groups, lexical orthographic effects were evident and stable over time only for correctly spelled words. Orthographic representations were intact in iRD children, but word processing took longer compared to TD. Children with spelling disorders had partly missing orthographic representations. Our study is the first to specify the underlying neurophysiology of word processing deficits associated with isolated literacy deficits. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Regional interdependence and manual therapy directed at the thoracic spine

PubMed Central

McDevitt, Amy; Young, Jodi; Mintken, Paul; Cleland, Josh

2015-01-01

Thoracic spine manipulation is commonly used by physical therapists for the management of patients with upper quarter pain syndromes. The theoretical construct for using thoracic manipulation for upper quarter conditions is a mainstay of a regional interdependence (RI) approach. The RI concept is likely much more complex and is perhaps driven by a neurophysiological response including those related to peripheral, spinal cord and supraspinal mechanisms. Recent evidence suggests that thoracic spine manipulation results in neurophysiological changes, which may lead to improved pain and outcomes in individuals with musculoskeletal disorders. The intent of this narrative review is to describe the research supporting the RI concept and its application to the treatment of individuals with neck and/or shoulder pain. Treatment utilizing both thrust and non-thrust thoracic manipulation has been shown to result in improvements in pain, range of motion and disability in patients with upper quarter conditions. Research has yet to determine optimal dosage, techniques or patient populations to which the RI approach should be applied; however, emerging evidence supporting a neurophysiological effect for thoracic spine manipulation may negate the need to fully answer this question. Certainly, there is a need for further research examining both the clinical efficacy and effectiveness of manual therapy interventions utilized in the RI model as well as the neurophysiological effects resulting from this intervention. PMID:26309384

Automatic detection of rhythmic and periodic patterns in critical care EEG based on American Clinical Neurophysiology Society (ACNS) standardized terminology.

PubMed

Fürbass, F; Hartmann, M M; Halford, J J; Koren, J; Herta, J; Gruber, A; Baumgartner, C; Kluge, T

2015-09-01

Continuous EEG from critical care patients needs to be evaluated time efficiently to maximize the treatment effect. A computational method will be presented that detects rhythmic and periodic patterns according to the critical care EEG terminology (CCET) of the American Clinical Neurophysiology Society (ACNS). The aim is to show that these detected patterns support EEG experts in writing neurophysiological reports. First of all, three case reports exemplify the evaluation procedure using graphically presented detections. Second, 187 hours of EEG from 10 critical care patients were used in a comparative trial study. For each patient the result of a review session using the EEG and the visualized pattern detections was compared to the original neurophysiology report. In three out of five patients with reported seizures, all seizures were reported correctly. In two patients, several subtle clinical seizures with unclear EEG correlation were missed. Lateralized periodic patterns (LPD) were correctly found in 2/2 patients and EEG slowing was correctly found in 7/9 patients. In 8/10 patients, additional EEG features were found including LPDs, EEG slowing, and seizures. The use of automatic pattern detection will assist in review of EEG and increase efficiency. The implementation of bedside surveillance devices using our detection algorithm appears to be feasible and remains to be confirmed in further multicenter studies. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Is appreciation of written education about pain neurophysiology related to changes in illness perceptions and health status in patients with fibromyalgia?

PubMed

van Ittersum, M W; van Wilgen, C P; Groothoff, J W; van der Schans, C P

2011-11-01

To investigate the appreciation of written education about pain neurophysiology in patients with fibromyalgia (FM) and its effects on illness perceptions and perceived health status. A booklet explaining pain neurophysiology was sent to participants with FM. Appreciation was assessed with 10 questions addressing relevance (0-30) and reassurance (0-30). Illness perceptions, catastrophizing and health status were measured with the Revised Illness Perception Questionnaire (IPQ-R), the Pain Catastrophizing Scale (PCS) and the Fibromyalgia Impact Questionnaire (FIQ) at baseline (T0), after a 2-week control period (T1) and 6 weeks after the intervention (T2). Forty-one patients participated. Mean (SD) scores for relevance and reassurance were 21.6 (5.6) and 18.7 (5.7), respectively. Only illness coherence, emotional representations, pain and fatigue changed significantly between T0 and T2. Correlations between appreciation and changes in outcomes ranged between r=0.00 and r=0.34. Although a majority of subjects appreciated the written information, it did not have clinically relevant effects on illness perceptions, catastrophizing or impact of FM on daily life. Written education about pain neurophysiology is inadequate toward changing illness perceptions, catastrophizing or perceived health status of participants with FM; education should be incorporated into a broader multidisciplinary self-management program. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Pressure effect on the long-range order in CeB6

NASA Astrophysics Data System (ADS)

Sera, M.; Ikeda, S.; Iwakubo, H.; Uwatoko, Y.; Hane, S.; Kosaka, M.; Kunii, S.

2006-08-01

The pressure effect of CeB6 was investigated. The pressure dependence of the Néel temperature, TN and the critical field from the antiferro-magnetic phase III to antiferro-quadrupolar phase II, HcIII-II of CeB6 exhibits the unusual pressure dependence that the suppression rate of HcIII-II is much larger than that of TN. In order to explain this unusual result, we have performed the mean field calculation for the 4-sublattice model assuming that the pressure dependence of TN, the antiferro-octupolar and quadrupolar temperatures, Toct and TQ as follows; dTN/dP<0, dToct/dP>dTQ/dP>0 and could explain the unusual pressure dependence of TN and HcIII-II.

Understanding the Mechanism of Magnetic Relaxation in Pentanuclear {MnIVMnIII2LnIII2} Single-Molecule Magnets.

PubMed

Vignesh, Kuduva R; Langley, Stuart K; Moubaraki, Boujemaa; Murray, Keith S; Rajaraman, Gopalan

2018-02-05

A new family of heterometallic pentanuclear complexes of formulas [Mn IV Mn III 2 Ln III 2 O 2 (benz) 4 (mdea) 3 (NO 3 ) 2 (MeOH)] (Ln = Dy (1-Dy), Tb (2-Tb), Gd (3-Gd), Eu (4-Eu), Sm (5-Sm), Nd (6-Nd), Pr (7-Pr); benz(H) = benzoic acid; mdeaH 2 = N-methyldiethanolamine) and [Mn IV Mn III 2 Ln III 2 O 2 (o-tol) 4 (mdea) 3 (NO 3 ) 2 (MeOH)] (Ln = Gd (8-Gd), Eu (9-Eu); o-tol(H) = o-toluic acid) have been isolated and structurally, magnetically, and theoretically characterized. dc magnetic susceptibility measurements reveal dominant antiferromagnetic magnetic interactions for each complex, except for 2-Tb and 3-Gd, which reveal an upturn in the χ M T product at low temperatures. The magnetic interactions between the spin centers in the Gd derivatives, 3-Gd and 8-Gd, which display markedly different χ M T vs T profiles, were found to be due to the interactions of the Gd III -Gd III ions which change from ferromagnetic (3-Gd) to antiferromagnetic (8-Gd) due to structural differences. ac magnetic susceptibility measurements reveal a nonzero out-of-phase component for 1-Dy and 7-Pr, but no maxima were observed above 2 K (H dc = 0 Oe), which suggests single-molecule magnet (SMM) behavior. Out-of-phase signals were observed for complexes 2-Tb, 4-Eu, 8-Gd, and 9-Eu, in the presence of a static dc field (H dc = 2000, 3000 Oe). The anisotropic nature of the lanthanide ions in the benzoate series (1-Dy, 2-Tb, 5-Sm, 6-Nd, and 7-Pr) were thoroughly investigated using ab initio methods. CASSCF calculations predict that the origin of SMM behavior in 1-Dy and 7-Pr and the applied field SMM behavior in 2-Tb does not solely originate from the single-ion anisotropy of the lanthanide ions. To fully understand the relaxation mechanism, we have employed the Lines model to fit the susceptibility data using the POLY_ANISO program, which suggests that the zero-field SMM behavior observed in complexes 1-Dy and 7-Pr is due to weak Mn III/IV -Ln III and Ln III -Ln III couplings and an unfavorable Ln III /Mn III /Mn IV anisotropy. In complexes 4-Eu, 8-Gd, and 9-Eu ab initio calculations indicate that the anisotropy of the Mn III ions solely gives rise to the possibility of SMM behavior. Complex 7-Pr is a Pr(III)-containing complex that displays zero-field SMM behavior, which is rare, and our study suggests the possibility of coupling weak SOC lanthanide metal ions to anisotropic transition-metal ions to derive SMM characteristics; however, enhancing the exchange coupling in {3d-4f} complexes is still a stubborn hurdle in harnessing new generation {3d-4f} SMMs.

A study of solar preflare activity using two-dimensional radio and SMM-XRP observations

NASA Technical Reports Server (NTRS)

Kundu, M. R.; Gopalswamy, N.; Saba, J. L. R.; Schmelz, J. T. S.; Strong, K. T.

1987-01-01

A study of type III activity at meter-decameter wavelengths in the preflare phase of the February 3, 1986 flare is presented, using data obtained with the Clark Lake Multifrequency Radioheliograph. This activity is compared with similar type III burst activity during the impulsive phase, and it is found that there is a displacement of burst sources between the onset and end times of the activity. A comparison of this displacement at three frequencies suggests that the type III emitting electrons gain access progressively to diverging and different field lines relative to the initial field lines. The energetics of the type III emitting electrons are inferred from observations and compared with those of the associated hard X-ray emitting electrons. The soft X-ray data from SMM-XRP show enhanced emission measure, density, and temperature in the region associated with the preflare type III activity.

A study of solar preflare activity using two-dimensional radio and SMM-XRP observations

NASA Astrophysics Data System (ADS)

Kundu, M. R.; Gopalswamy, N.; Saba, J. L. R.; Schmelz, J. T. S.; Strong, K. T.

1987-09-01

The authors present a study of type III activity at meter-decameter wavelengths in the preflare phase of the 1986 February 3 flare using data obtained with the Clark Lake Multifrequency Radioheliograph. They compare this activity with similar type III burst activity during the impulsive phase and find that there is a displacement of burst sources between the onset and end times of the activity. A comparison of this displacement at three frequencies suggests that the type III emitting electrons gain access progressively to diverging and different field lines relative to the initial field lines. The energetics of the type III emitting electrons are inferred from observations and compared with those of the associated hard X-ray emitting electrons. The soft X-ray data from SMM-XRP shows enhanced emission measure, density and temperature in the region associated with the preflare type III activity.

From Structure to Circuits: The Contribution of MEG Connectivity Studies to Functional Neurosurgery.

PubMed

Pang, Elizabeth W; Snead Iii, O C

2016-01-01

New advances in structural neuroimaging have revealed the intricate and extensive connections within the brain, data which have informed a number of ambitious projects such as the mapping of the human connectome. Elucidation of the structural connections of the brain, at both the macro and micro levels, promises new perspectives on brain structure and function that could translate into improved outcomes in functional neurosurgery. The understanding of neuronal structural connectivity afforded by these data now offers a vista on the brain, in both healthy and diseased states, that could not be seen with traditional neuroimaging. Concurrent with these developments in structural imaging, a complementary modality called magnetoencephalography (MEG) has been garnering great attention because it too holds promise for being able to shed light on the intricacies of functional brain connectivity. MEG is based upon the elemental principle of physics that an electrical current generates a magnetic field. Hence, MEG uses highly sensitive biomagnetometers to measure extracranial magnetic fields produced by intracellular neuronal currents. Put simply then, MEG is a measure of neurophysiological activity, which captures the magnetic fields generated by synchronized intraneuronal electrical activity. As such, MEG recordings offer exquisite resolution in the time and oscillatory domain and, as well, when co-registered with magnetic resonance imaging (MRI), offer excellent resolution in the spatial domain. Recent advances in MEG computational and graph theoretical methods have led to studies of connectivity in the time-frequency domain. As such, MEG can elucidate a neurophysiological-based functional circuitry that may enhance what is seen with MRI connectivity studies. In particular, MEG may offer additional insight not possible by MRI when used to study complex eloquent function, where the precise timing and coordination of brain areas is critical. This article will review the traditional use of MEG for functional neurosurgery, describe recent advances in MEG connectivity analyses, and consider the additional benefits that could be gained with the inclusion of MEG connectivity studies. Since MEG has been most widely applied to the study of epilepsy, we will frame this article within the context of epilepsy surgery and functional neurosurgery for epilepsy.

Fibronectin module FN(III)9 adsorption at contrasting solid model surfaces studied by atomistic molecular dynamics.

PubMed

Kubiak-Ossowska, Karina; Mulheran, Paul A; Nowak, Wieslaw

2014-08-21

The mechanism of human fibronectin adhesion synergy region (known as integrin binding region) in repeat 9 (FN(III)9) domain adsorption at pH 7 onto various and contrasting model surfaces has been studied using atomistic molecular dynamics simulations. We use an ionic model to mimic mica surface charge density but without a long-range electric field above the surface, a silica model with a long-range electric field similar to that found experimentally, and an Au {111} model with no partial charges or electric field. A detailed description of the adsorption processes and the contrasts between the various model surfaces is provided. In the case of our model silica surface with a long-range electrostatic field, the adsorption is rapid and primarily driven by electrostatics. Because it is negatively charged (-1e), FN(III)9 readily adsorbs to a positively charged surface. However, due to its partial charge distribution, FN(III)9 can also adsorb to the negatively charged mica model because of the absence of a long-range repulsive electric field. The protein dipole moment dictates its contrasting orientation at these surfaces, and the anchoring residues have opposite charges to the surface. Adsorption on the model Au {111} surface is possible, but less specific, and various protein regions might be involved in the interactions with the surface. Despite strongly influencing the protein mobility, adsorption at these model surfaces does not require wholesale FN(III)9 conformational changes, which suggests that the biological activity of the adsorbed protein might be preserved.

Neurophysiology Summary

NASA Technical Reports Server (NTRS)

Paloski, William H.

2001-01-01

The terrestrial gravitational field serves as an important orientation reference for human perception and movement, being continually monitored by sensory receptors in the skin, muscles, joints, and vestibular otolith organs. Cues from these graviceptors are used by the brain to estimate spatial orientation and to control balance and movement. Changes in these cues associated with the tonic changes in gravity (gravito-inertial force),during the launch and entry phases of space flight missions result in altered perceptions, degraded motor control performance, and in some cases, "motion" sickness during, and for a period of time after, the g-transitions. In response to these transitions, however, physiological and behavioral response mechanisms are triggered to compensate for altered graviceptor cues and/or to adapt to the new sensory environment. Basic research in the neurophysiology discipline is focused on understanding the characteristic features of and the underlying mechanisms for the normal human response to tonic changes in the gravito-inertial force environment. These studies address fundamental questions regarding the role of graviceptors in orientation and movement in the terrestrial environment, as well as the capacity, specificity, and modes for neural plasticity in the sensory-motor and perceptual systems of the brain. At the 2001 workshop basic research studies were presented addressing: neuroanatomical responses to altered gravity environments, the neural mechanisms for resolving the ambiguity between tilting and translational stimuli in otolith organ sensory input, interactions between the vestibular system and the autonomic nervous system , the roles of haptic and visual cues in spatial orientation, mechanisms for training environment-appropriate sensorimotor responses triggered by environment-specific context cues, and studies of sensori-motor control of posture and locomotion in the terrestrial environment with and without recent exposure to space flight. Building on these basic research studies are more applied studies focused on the development of countermeasures to the untoward neurophysiological responses to space flight. At the 2001 workshop, applied research studies were presented addressing issues related to the use of rotational artificial gravity (centripetal acceleration) as a multisystem (bone, muscle, cardiovascular, and, perhaps, neurovestibular) countermeasure. Also presented was a clinical study reporting on a new rating system for clinical evaluation of postflight functional neurological status.

Neural adaptation accounts for the dynamic resizing of peripersonal space: evidence from a psychophysical-computational approach.

PubMed

Noel, Jean-Paul; Blanke, Olaf; Magosso, Elisa; Serino, Andrea

2018-06-01

Interactions between the body and the environment occur within the peripersonal space (PPS), the space immediately surrounding the body. The PPS is encoded by multisensory (audio-tactile, visual-tactile) neurons that possess receptive fields (RFs) anchored on the body and restricted in depth. The extension in depth of PPS neurons' RFs has been documented to change dynamically as a function of the velocity of incoming stimuli, but the underlying neural mechanisms are still unknown. Here, by integrating a psychophysical approach with neural network modeling, we propose a mechanistic explanation behind this inherent dynamic property of PPS. We psychophysically mapped the size of participant's peri-face and peri-trunk space as a function of the velocity of task-irrelevant approaching auditory stimuli. Findings indicated that the peri-trunk space was larger than the peri-face space, and, importantly, as for the neurophysiological delineation of RFs, both of these representations enlarged as the velocity of incoming sound increased. We propose a neural network model to mechanistically interpret these findings: the network includes reciprocal connections between unisensory areas and higher order multisensory neurons, and it implements neural adaptation to persistent stimulation as a mechanism sensitive to stimulus velocity. The network was capable of replicating the behavioral observations of PPS size remapping and relates behavioral proxies of PPS size to neurophysiological measures of multisensory neurons' RF size. We propose that a biologically plausible neural adaptation mechanism embedded within the network encoding for PPS can be responsible for the dynamic alterations in PPS size as a function of the velocity of incoming stimuli. NEW & NOTEWORTHY Interactions between body and environment occur within the peripersonal space (PPS). PPS neurons are highly dynamic, adapting online as a function of body-object interactions. The mechanistic underpinning PPS dynamic properties are unexplained. We demonstrate with a psychophysical approach that PPS enlarges as incoming stimulus velocity increases, efficiently preventing contacts with faster approaching objects. We present a neurocomputational model of multisensory PPS implementing neural adaptation to persistent stimulation to propose a neurophysiological mechanism underlying this effect.

Magnitude and behavior of cross-talk effects in multichannel electrophysiology experiments.

PubMed

Nelson, Matthew J; Valtcheva, Silvana; Venance, Laurent

2017-07-01

Modern neurophysiological experiments frequently involve multiple channels separated by very small distances. A unique methodological concern for multiple-electrode experiments is that of capacitive coupling (cross-talk) between channels. Yet the nature of the cross-talk recording circuit is not well known in the field, and the extent to which it practically affects neurophysiology experiments has never been fully investigated. Here we describe a simple electrical circuit model of simultaneous recording and stimulation with two or more channels and experimentally verify the model using ex vivo brain slice and in vivo whole-brain preparations. In agreement with the model, we find that cross-talk amplitudes increase nearly linearly with the impedance of a recording electrode and are larger for higher frequencies. We demonstrate cross-talk contamination of action potential waveforms from intracellular to extracellular channels, which is observable in part because of the different orders of magnitude between the channels. This contamination is electrode impedance-dependent and matches predictions from the model. We use recently published parameters to simulate cross-talk in high-density multichannel extracellular recordings. Cross-talk effectively spatially smooths current source density (CSD) estimates in these recordings and induces artefactual phase shifts where underlying voltage gradients occur; however, these effects are modest. We show that the effects of cross-talk are unlikely to affect most conclusions inferred from neurophysiology experiments when both originating and receiving electrode record signals of similar magnitudes. We discuss other types of experiments and analyses that may be susceptible to cross-talk, techniques for detecting and experimentally reducing cross-talk, and implications for high-density probe design. NEW & NOTEWORTHY We develop and experimentally verify an electrical circuit model describing cross-talk that necessarily occurs between two channels. Recorded cross-talk increased with electrode impedance and signal frequency. We recorded cross-talk contamination of spike waveforms from intracellular to extracellular channels. We simulated high-density multichannel extracellular recordings and demonstrate spatial smoothing and phase shifts that cross-talk enacts on CSD measurements. However, when channels record similar-magnitude signals, effects are modest and unlikely to affect most conclusions. Copyright © 2017 the American Physiological Society.

Neurophysiological Markers of Emotion Processing in Burnout Syndrome.

PubMed

Golonka, Krystyna; Mojsa-Kaja, Justyna; Popiel, Katarzyna; Marek, Tadeusz; Gawlowska, Magda

2017-01-01

The substantial body of research employing subjective measures indicates that burnout syndrome is associated with cognitive and emotional dysfunctions. The growing amount of neurophysiological and neuroimaging research helps in broadening existing knowledge of the neural mechanisms underlying core burnout components (emotional exhaustion and depersonalization/cynicism) that are inextricably associated with emotional processing. In the presented EEG study, a group of 93 participants (55 women; mean age = 35.8) were selected for the burnout group or the demographically matched control group on the basis of the results of the Maslach Burnout Inventory - General Survey (MBI-GS) and the Areas of Worklife Survey (AWS). Subjects then participated in an EEG experiment using two experimental procedures: a facial recognition task and viewing of passive pictures. The study focuses on analyzing event-related potentials (ERPs): N170, VPP, EPN, and LPP, as indicators of emotional information processing. Our results show that burnout subjects, as compared to the control group, demonstrate significantly weaker response to affect-evoking stimuli, indexed by a decline in VPP amplitude to emotional faces and decreased EPN amplitude in processing emotional scenes. The analysis of N170 and LPP showed no significant between-group difference. The correlation analyses revealed that VPP and EPN, which are ERP components related to emotional processing, are associated with two core burnout symptoms: emotional exhaustion and cynicism. To our knowledge, we are one of the first research groups to use ERPs to demonstrate such a relationship between neurophysiological activity and burnout syndrome in the context of emotional processing. Thus, in conclusion we emphasized that the decreased amplitude of VPP and EPN components in the burnout group may be a neurophysiological manifestation of emotional blunting and may be considered as neurophysiological markers of emotional exhaustion and cynicism. Additionally, we did not observe a decrease in LPP, which may be considered as a marker that significantly differentiates burnout from depression.

Neurophysiological Markers of Emotion Processing in Burnout Syndrome

PubMed Central

Golonka, Krystyna; Mojsa-Kaja, Justyna; Popiel, Katarzyna; Marek, Tadeusz; Gawlowska, Magda

2017-01-01

The substantial body of research employing subjective measures indicates that burnout syndrome is associated with cognitive and emotional dysfunctions. The growing amount of neurophysiological and neuroimaging research helps in broadening existing knowledge of the neural mechanisms underlying core burnout components (emotional exhaustion and depersonalization/cynicism) that are inextricably associated with emotional processing. In the presented EEG study, a group of 93 participants (55 women; mean age = 35.8) were selected for the burnout group or the demographically matched control group on the basis of the results of the Maslach Burnout Inventory – General Survey (MBI-GS) and the Areas of Worklife Survey (AWS). Subjects then participated in an EEG experiment using two experimental procedures: a facial recognition task and viewing of passive pictures. The study focuses on analyzing event-related potentials (ERPs): N170, VPP, EPN, and LPP, as indicators of emotional information processing. Our results show that burnout subjects, as compared to the control group, demonstrate significantly weaker response to affect-evoking stimuli, indexed by a decline in VPP amplitude to emotional faces and decreased EPN amplitude in processing emotional scenes. The analysis of N170 and LPP showed no significant between-group difference. The correlation analyses revealed that VPP and EPN, which are ERP components related to emotional processing, are associated with two core burnout symptoms: emotional exhaustion and cynicism. To our knowledge, we are one of the first research groups to use ERPs to demonstrate such a relationship between neurophysiological activity and burnout syndrome in the context of emotional processing. Thus, in conclusion we emphasized that the decreased amplitude of VPP and EPN components in the burnout group may be a neurophysiological manifestation of emotional blunting and may be considered as neurophysiological markers of emotional exhaustion and cynicism. Additionally, we did not observe a decrease in LPP, which may be considered as a marker that significantly differentiates burnout from depression. PMID:29326619

Auditory-neurophysiological responses to speech during early childhood: Effects of background noise

PubMed Central

White-Schwoch, Travis; Davies, Evan C.; Thompson, Elaine C.; Carr, Kali Woodruff; Nicol, Trent; Bradlow, Ann R.; Kraus, Nina

2015-01-01

Early childhood is a critical period of auditory learning, during which children are constantly mapping sounds to meaning. But learning rarely occurs under ideal listening conditions—children are forced to listen against a relentless din. This background noise degrades the neural coding of these critical sounds, in turn interfering with auditory learning. Despite the importance of robust and reliable auditory processing during early childhood, little is known about the neurophysiology underlying speech processing in children so young. To better understand the physiological constraints these adverse listening scenarios impose on speech sound coding during early childhood, auditory-neurophysiological responses were elicited to a consonant-vowel syllable in quiet and background noise in a cohort of typically-developing preschoolers (ages 3–5 yr). Overall, responses were degraded in noise: they were smaller, less stable across trials, slower, and there was poorer coding of spectral content and the temporal envelope. These effects were exacerbated in response to the consonant transition relative to the vowel, suggesting that the neural coding of spectrotemporally-dynamic speech features is more tenuous in noise than the coding of static features—even in children this young. Neural coding of speech temporal fine structure, however, was more resilient to the addition of background noise than coding of temporal envelope information. Taken together, these results demonstrate that noise places a neurophysiological constraint on speech processing during early childhood by causing a breakdown in neural processing of speech acoustics. These results may explain why some listeners have inordinate difficulties understanding speech in noise. Speech-elicited auditory-neurophysiological responses offer objective insight into listening skills during early childhood by reflecting the integrity of neural coding in quiet and noise; this paper documents typical response properties in this age group. These normative metrics may be useful clinically to evaluate auditory processing difficulties during early childhood. PMID:26113025

Progressive levels of physical dependence to tobacco coincide with changes in the anterior cingulum bundle microstructure.

PubMed

Huang, Wei; DiFranza, Joseph R; Kennedy, David N; Zhang, Nanyin; Ziedonis, Douglas; Ursprung, Sanouri; King, Jean A

2013-01-01

The tobacco withdrawal syndrome indicates the development of neurophysiologic dependence. Clinical evidence indicates that neurophysiologic dependence develops through a set sequence of symptom presentation that can be assessed with a new 3-item survey measure of wanting, craving, and needing tobacco, the Level of Physical Dependence (PD). This study sought to determine if advancing neurophysiologic dependence as measured by the Level of PD correlates with characteristics of white matter structure measured by Fractional Anisotropy (FA). Diffusion-MRI based FA and diffusion tensor imaging probabilistic tractography were used to evaluate 11 smokers and 10 nonsmokers. FA was also examined in relation to two additional measures of dependence severity, the Hooked on Nicotine Checklist (HONC), and the Fagerström Test for Nicotine Dependence (FTND). Among smokers, FA in the left anterior cingulate bundle (ACb) correlated negatively with the Level of PD (r = -0.68, p = 0.02) and HONC scores (r = -0.65, p = 0.03), but the correlation for the FTND did not reach statistical significance (r = -49, p = 0.12). With advancing Levels of PD, the density of streamlines between the ACb and precuneus increased (r = -0.67, p<0.05) and those between the ACb and white matter projecting to the superior-frontal cortex (r = -0.86, p = 0.0006) decreased significantly. The correlations between neural structure and both the clinical Level of PD survey measure and the HONC suggest that the Level of PD and the HONC may reflect the microstructural integrity of white matter, as influenced by tobacco abuse. Given that the Level of PD is measuring a sequence of symptoms of neurophysiologic dependence that develops over time, the correlation between the Level of PD and neural structure suggests that these features might represent neuroplastic changes that develop over time to support the development of neurophysiologic dependence.

Resting State EEG in Children With Learning Disabilities: An Independent Component Analysis Approach.

PubMed

Jäncke, Lutz; Alahmadi, Nsreen

2016-01-01

In this study, the neurophysiological underpinnings of learning disabilities (LD) in children are examined using resting state EEG. We were particularly interested in the neurophysiological differences between children with learning disabilities not otherwise specified (LD-NOS), learning disabilities with verbal disabilities (LD-Verbal), and healthy control (HC) children. We applied 2 different approaches to examine the differences between the different groups. First, we calculated theta/beta and theta/alpha ratios in order to quantify the relationship between slow and fast EEG oscillations. Second, we used a recently developed method for analyzing spectral EEG, namely the group independent component analysis (gICA) model. Using these measures, we identified substantial differences between LD and HC children and between LD-NOS and LD-Verbal children in terms of their spectral EEG profiles. We obtained the following findings: (a) theta/beta and theta/alpha ratios were substantially larger in LD than in HC children, with no difference between LD-NOS and LD-Verbal children; (b) there was substantial slowing of EEG oscillations, especially for gICs located in frontal scalp positions, with LD-NOS children demonstrating the strongest slowing; (c) the estimated intracortical sources of these gICs were mostly located in brain areas involved in the control of executive functions, attention, planning, and language; and (d) the LD-Verbal children demonstrated substantial differences in EEG oscillations compared with LD-NOS children, and these differences were localized in language-related brain areas. The general pattern of atypical neurophysiological activation found in LD children suggests that they suffer from neurophysiological dysfunction in brain areas involved with the control of attention, executive functions, planning, and language functions. LD-Verbal children also demonstrate atypical activation, especially in language-related brain areas. These atypical neurophysiological activation patterns might provide a helpful guide for rehabilitation strategies to treat the deficiencies in these children with LD. © EEG and Clinical Neuroscience Society (ECNS) 2015.

Non ictal onset zone: A window to ictal dynamics.

PubMed

Afra, Pegah; Hanrahan, Sara J; Kellis, Spencer Sterling; House, Paul

2017-01-01

The focal and network concepts of epilepsy present different aspects of electroclinical phenomenon of seizures. Here, we present a 23-year-old man undergoing surgical evaluation with left fronto-temporal electrocorticography (ECoG) and microelectrode-array (MEA) in the middle temporal gyrus (MTG). We compare action-potential (AP) and local field potentials (LFP) recorded from MEA with ECoG. Seizure onset in the mesial-temporal lobe was characterized by changes in the pattern of AP-firing without clear changes in LFP or ECoG in MTG. This suggests simultaneous analysis of neuronal activity in differing spatial scales and frequency ranges provide complementary insights into how focal and network neurophysiological activity contribute to ictal activity.

Chapter 18: the origins of functional brain imaging in humans.

PubMed

Raichle, Marcus E

2010-01-01

Functional brain imaging in humans as we presently know it began when the experimental strategies of cognitive psychology were combined with modern brain imaging techniques, first positron emission tomography (PET) and then functional magnetic resonance imaging (fMRI), to examine how brain function supports mental activities. This marriage of disciplines and techniques galvanized the field of cognitive neuroscience, which has rapidly expanded to include a broad range of the social sciences as well as basic scientists interested in the neurophysiology, cell biology and genetics of the imaging signals. While much of this work has transpired over the past couple of decades, its roots can be traced back more than a century.

Theoretical Crystal-Field Calculations for Rare-Earth Ions in III-V semiconductor Compounds

DTIC Science & Technology

1991-10-01

AD-A243 098 TIC HDL-TM-91-16 1 Ii! 1 I!EiIII ’ii F CT F October 1991 aC7 1991J Theoretical Crystal-Field Calculations for Rare-Earth Ions in III-V...0188). Washngton. DC 20503 1 . AGENCY USE ONLY (Leave bia*) 2. REPORT DATE 3. REPORT TYPE AND DATES COVERED October 1991 Summary, from Jan 91 toJul 91...Laboratories HDL-TM-9 1 -16 2800 Powder Mill Road Adelphi, MD 20783-1197 9. SPONSORNG#AONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSORINGMONITORING

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morioka, A.; Misawa, H.; Obara, T.

Solar micro-type III radio bursts are elements of the so-called type III storms and are characterized by short-lived, continuous, and weak emissions. Their frequency of occurrence with respect to radiation power is quite different from that of ordinary type III bursts, suggesting that the generation process is not flare-related, but due to some recurrent acceleration processes around the active region. We examine the relationship of micro-type III radio bursts with coronal streamers. We also explore the propagation channel of bursts in the outer corona, the acceleration process, and the escape route of electron beams. It is observationally confirmed that micro-typemore » III bursts occur near the edge of coronal streamers. The magnetic field line of the escaping electron beams is tracked on the basis of the frequency drift rate of micro-type III bursts and the electron density distribution model. The results demonstrate that electron beams are trapped along closed dipolar field lines in the outer coronal region, which arise from the interface region between the active region and the coronal hole. A 22 year statistical study reveals that the apex altitude of the magnetic loop ranges from 15 to 50 R{sub S}. The distribution of the apex altitude has a sharp upper limit around 50 R{sub S} suggesting that an unknown but universal condition regulates the upper boundary of the streamer dipolar field.« less

Behavioral neurophysiology: insights into seeing and grasping.

PubMed

Wise, S P; Desimone, R

1988-11-04

One marvels at a batter's ability to hit a baseball traveling at 150 kilometers per hour or a monkey's skill in snatching a flying insect. Indeed, the ability of many animals to reach out, grasp, and manipulate objects is a feat of biological engineering unmatched by even state-of-the-art robots. But how are the objects of our attention chosen and how are the eyes and hands directed to it? Recent progress in behavioral neurophysiology has clarified some of the brain mechanisms at work.

The study of human higher mental functions as they relate to neurophysiological processes and personal characteristics

NASA Astrophysics Data System (ADS)

Runnova, Anastasiya; Zhuravlev, Maxim; Kulanin, Roman; Protasov, Pavel; Hramov, Alexander; Koronovskii, Alexey

2018-02-01

In this paper we study the correlation between the neurophysiological processes and personal characteristics arising in the processes of human higher mental functions. We find that the activity of the brain correlates with the results of psychological tests (according to the Cattell test). Experimental studies and math processing are described for operation design with the registration of human multi-channel EEG data in two phases (the processes of passive wakefulness (background) and special psychological testing (active phase)).

How to Measure Outcomes of Peripheral Nerve Surgery

PubMed Central

Wang, Yirong; Sunitha, Malay; Chung, Kevin C.

2013-01-01

Synopsis Evaluation of outcomes after peripheral nerve surgeries include a number of assessment methods that reflect different aspects of recovery, including reinnervation, tactile gnosis, integrated sensory and motor function, pain and discomfort, neurophysiological and patient- reported outcomes. This review makes a list of measurements addressing these aspects as well as advantage and disadvantage of each tool. Because of complexities of neurophysiology, assessment remains a difficult process, which requires researchers focus on measurements best relevant to specific conditions and research questions. PMID:23895715

How to measure outcomes of peripheral nerve surgery.

PubMed

Wang, Yirong; Sunitha, Malay; Chung, Kevin C

2013-08-01

Evaluation of outcomes after peripheral nerve surgeries include several assessment methods that reflect different aspects of recovery, including reinnervation, tactile gnosis, integrated sensory and motor function, pain and discomfort, and neurophysiologic and patient-reported outcomes. This review lists measurements addressing these aspects as well as the advantages and disadvantages of each tool. Because of complexities of neurophysiology, assessment remains a difficult process, which requires researchers to focus on measurements best relevant to specific conditions and research questions. Copyright © 2013 Elsevier Inc. All rights reserved.

Rapid oxidation of geothermal arsenic(III) in streamwaters of the eastern Sierra Nevada

USGS Publications Warehouse

Wilkie, J.A.; Hering, J.G.

1998-01-01

Arsenic redox cycling was examined in source waters of the Los Angeles Aqueduct, specifically at Hot Creek, a tributary of the Owens River. Elevated arsenic concentrations in Hot Creek result from geothermal inputs. Total arsenic and As(III) concentrations were determined in the creek and in hot spring pools along its banks. Samples were processed in the field using anion-exchange columns to separate inorganic As(III) and As(V) species. Downstream of the geothermal inputs, decreasing contributions of As(III) to total arsenic concentrations indicated rapid in-stream oxidation of As(III) to As(V) with almost complete oxidation occurring within 1200 m. Based on assumed plug flow transport and a flow velocity of about 0.4 m/s, the pseudo- first-order half-life calculated for this reaction was approximately 0.3 h. Conservative transport of total dissolved arsenic was observed over the reach. Pseudo-first-order reaction rates determined for As(III) oxidation in batch studies conducted in the field with aquatic macrophytes and/or macrophyte surface matter were comparable to the in-stream oxidation rate observed along Hot Creek. In batch kinetic studies, oxidation was not observed after sterile filtration or after the addition of antibiotics, which indicates that bacteria attached to submerged macrophytes are mediating the rapid As(III) oxidation reaction.Arsenic redox cycling was examined in source waters of the Los Angeles Aqueduct, specifically at Hot Creek, a tributary of the Owens River. Elevated arsenic concentrations in Hot Creek result from geothermal inputs. Total arsenic and As(III) concentrations were determined in the creek and in hot spring pools along its banks. Samples were processed in the field using anion-exchange columns to separate inorganic As(III) and As(V) species. Downstream of the geothermal inputs, decreasing contributions of As(III) to total arsenic concentrations indicated rapid in-stream oxidation of As(III) to As(V) with almost complete oxidation occurring within 1200 m. Based on assumed plug flow transport and a flow velocity of about 0.4 m/s, the pseudo-first-order half-life calculated for this reaction was approximately 0.3 h. Conservative transport of total dissolved arsenic was observed over the reach. Pseudo-first-order reaction rates determined for As(III) oxidation in batch studies conducted in the field with aquatic macrophytes and/or macrophyte surface matter were comparable to the in-stream oxidation rate observed along Hot Creek. In batch kinetic studies, oxidation was not observed after sterile filtration or after the addition of antibiotics, which indicates that bacteria attached to submerged macrophytes are mediating the rapid As(III) oxidation reaction.

Randomness increases self-reported anxiety and neurophysiological correlates of performance monitoring

PubMed Central

Kay, Aaron C.; Inzlicht, Michael

2015-01-01

Several prominent theories spanning clinical, social and developmental psychology suggest that people are motivated to see the world as a sensible orderly place. These theories presuppose that randomness is aversive because it is associated with unpredictability. If this is the case, thinking that the world is random should lead to increased anxiety and heightened monitoring of one’s actions and their consequences. Here, we conduct experimental tests of both of these ideas. Participants read one of three passages: (i) comprehensible order, (ii) incomprehensible order and (iii) randomness. In Study 1, we examined the effects of these passages on self-reported anxiety. In Study 2, we examined the effects of the same manipulation on the error-related negativity (ERN), an event-related brain potential associated with performance monitoring. We found that messages about randomness increased self-reported anxiety and ERN amplitude relative to comprehensible order, whereas incomprehensible order had intermediate effects. These results lend support to the theoretically important idea that randomness is unsettling because it implies that the world is unpredictable. PMID:25062840

Perception of Upright: Multisensory Convergence and the Role of Temporo-Parietal Cortex

PubMed Central

Kheradmand, Amir; Winnick, Ariel

2017-01-01

We inherently maintain a stable perception of the world despite frequent changes in the head, eye, and body positions. Such “orientation constancy” is a prerequisite for coherent spatial perception and sensorimotor planning. As a multimodal sensory reference, perception of upright represents neural processes that subserve orientation constancy through integration of sensory information encoding the eye, head, and body positions. Although perception of upright is distinct from perception of body orientation, they share similar neural substrates within the cerebral cortical networks involved in perception of spatial orientation. These cortical networks, mainly within the temporo-parietal junction, are crucial for multisensory processing and integration that generate sensory reference frames for coherent perception of self-position and extrapersonal space transformations. In this review, we focus on these neural mechanisms and discuss (i) neurobehavioral aspects of orientation constancy, (ii) sensory models that address the neurophysiology underlying perception of upright, and (iii) the current evidence for the role of cerebral cortex in perception of upright and orientation constancy, including findings from the neurological disorders that affect cortical function. PMID:29118736

Effect of relaxation on working memory and the Bispectral Index of the EEG.

PubMed

Hudetz, Judith A; Hudetz, Anthony G; Reddy, Diane M

2004-08-01

Beneficial effects of relaxation on cardiovascular and immune functions and on memory has been implied but an empirical relationship between task performance and anxiety reduction has not been reported. In this study, we investigated whether guided imagery of relatively short duration would decrease S-Anxiety and electroencephalogram Bispectral Index and improve working memory. 42 participants (age: M=39, SD=11, 14 men, 28 women, university students and VA Medical Center employees, recruited by their professor or by fellow employees) underwent relaxation by 16-min. guided imagery or no treatment (control). Spielberger's State-Trait Anxiety Inventory and the WAIS-III Letter-Number Sequencing Test were administered before and after relaxation. S-Anxiety and BIS Index decreased and the Letter-Number test score increased by 30% after relaxation but not in the control group. This score was higher for participants with low anxiety and BIS Index. There was no significant difference between the groups before treatment. The results suggest that guided imagery of short duration produces relaxation as measured by psychological and neurophysiological indices and improves working memory performance.

Results of TRT after eighteen months: our experience.

PubMed

Baracca, Giovanna N; Forti, Stella; Crocetti, Andrea; Fagnani, Enrico; Scotti, Alberto; Del Bo, Luca; Ambrosetti, Umberto

2007-05-01

The aim of this study was to evaluate the efficacy of TRT in patients suffering from tinnitus. The tinnitus disorder affects about 10-15% of the population and, in one person out of a hundred, it is a disabling disorder. TRT treatment is based on Jastreboff's neurophysiological model. TRT consists of two parts: counselling, and sound therapy by means of dedicated hearing aids and sound generators. It proved to be useful to reduce the symptoms related to tinnitus. Jastreboff's structured interviews were proposed to a sample of 51 patients with tinnitus belonging to the I-II-III-IV classes according to Jastreboff. These patients were treated for 18 months. Sixty-eight percent of patients reported a reduction in the symptoms related to tinnitus, such as sleep disturbance, problems in concentration, and inability to relax. A percentage (64.7%) of patients thought that their quality of life was improved. Patients who had suffered from tinnitus for less than one year achieved significantly better results than patients who had suffered for a longer period of time. TRT is an effective tool in the treatment of tinnitus.

Behavioral and neurosensory responses of the boll weevil,Anthonomus grandis Boh. (Coleoptera: Curculionidae), to fluorinated analogs of aldehyde components of its pheromone.

PubMed

Dickens, J C; Prestwich, G D; Sun, W C

1991-06-01

Competitive field tests with α-fluorinated analogs of compounds III and IV (III-α-F and IV-α-F, respectively) of the boll weevil,Anthonomus grandis Boh., aggregation pheromone showed these compounds, when combined with the other pheromone components [(±)-I and II], to be as attractive as grandlure [(+)-I, II, and III+IV]. Dose-response curves constructed from electroantennograms of male boll weevils to serial stimulus loads of III, IV, III-α-F, IV-α-F, and the corresponding acyl fluorinated analogs (III-acyl-F and IV-acyl-F) showed the α-fiuorinated analogs to be as active as the pheromone components (threshold=0.1 μg), while the acyl fluorinated analogs had a 10-100 x higher threshold (=1-10 μg). Single-neuron recordings showed that IV neurons and II neurons (Dickens, 1990) responded to IV-α-F and III-α-F, respectively, while IV-acyl-F and III-acyl-F were inactive. Since a previous study showed compounds I, II, and IV to be essential for behavioral responses in the field, it seems likely that the activity of the α-fluorinated analogs observed here is due to the stimulation of IV neurons by IV-α-F as indicated in single neuron recordings.

Synthesis, structure, luminescence, and magnetic properties of a single-ion magnet "mer"-[tris(N-[(imidazol-4-yl)-methylidene]-DL-phenylalaninato)terbium(III) and related "fac"-DL-alaninato derivative.

PubMed

Yamauchi, Suguru; Fujinami, Takeshi; Matsumoto, Naohide; Mochida, Naotaka; Ishida, Takayuki; Sunatsuki, Yukinari; Watanabe, Masayuki; Tsuchimoto, Masanobu; Coletti, Cecilia; Re, Nazzareno

2014-06-16

Two Tb(III) complexes with the same N6O3 donor atoms but different coordination geometries, "fac"-[Tb(III)(HL(DL-ala))3]·7H2O (1) and "mer"-[Tb(III)(HL(DL-phe))3]·7H2O (2), were synthesized, where H2L(DL-ala) and H2L(DL-phe) are N-[(imidazol-4-yl)methylidene]-DL-alanine and -DL-phenylalanine, respectively. Each Tb(III) ion is coordinated by three electronically mononegative NNO tridentate ligands to form a coordination geometry of a tricapped trigonal prism. Compound 1 consists of enantiomers "fac"-[Tb(III)(HL(D-ala))3] and "fac"-[Tb(III)(HL(L-ala))3], while 2 consists of "mer"-[Tb(III)(HL(D-phe))2(HL(L-phe))] and "mer"-[Tb(III)(HL(D-phe))(HL(L-phe))2]. Magnetic data were analyzed by a spin Hamiltonian including the crystal field effect on the Tb(III) ion (4f(8), J = 6, S = 3, L = 3, gJ = 3/2, (7)F6). The Stark splitting of the ground state (7)F6 was evaluated from magnetic analysis, and the energy diagram pattern indicated easy-plane and easy-axis (Ising type) magnetic anisotropies for 1 and 2, respectively. Highly efficient luminescences with Φ = 0.50 and 0.61 for 1 and 2, respectively, were observed, and the luminescence fine structure due to the (5)D4 → (7)F6 transition is in good accordance with the energy diagram determined from magnetic analysis. The energy diagram of 1 shows an approximate single-well potential curve, whereas that of 2 shows a double- or quadruple-well potential within the (7)F6 multiplets. Complex 2 displayed an onset of the out-of-phase signal in alternating current (ac) susceptibility at a direct current bias field of 1000 Oe on cooling down to 1.9 K. A slight frequency dependence was recorded around 2 K. On the other hand, 1 did not show any meaningful out-of-phase ac susceptibility. Pulsed-field magnetizations of 1 and 2 were measured below 1.6 K, and only 2 exhibited magnetic hysteresis. This finding agrees well with the energy diagram pattern from crystal field calculation on 1 and 2. DFT calculation allowed us to estimate the negative charge distribution around the Tb(III) ion, giving a rationale to the different magnetic anisotropies of 1 and 2.

Repeatability of automated perimetry: a comparison between standard automated perimetry with stimulus size III and V, matrix, and motion perimetry.

PubMed

Wall, Michael; Woodward, Kimberly R; Doyle, Carrie K; Artes, Paul H

2009-02-01

Standard automated perimetry (SAP) shows a marked increase in variability in damaged areas of the visual field. This study was conducted to test the hypothesis that larger stimuli are associated with more uniform variability, by investigating the retest variability of four perimetry tests: standard automated perimetry size III (SAP III), with the SITA standard strategy; SAP size V (SAP V), with the full-threshold strategy; Matrix (FDT II), and Motion perimetry. One eye each of 120 patients with glaucoma was examined on the same day with these four perimetric tests and retested 1 to 8 weeks later. The decibel scales were adjusted to make the test's scales numerically similar. Retest variability was examined by establishing the distributions of retest threshold estimates, for each threshold level observed at the first test. The 5th and 95th percentiles of the retest distribution were used as point-wise limits of retest variability. Regression analyses were performed to quantify the relationship between visual field sensitivity and variability. With SAP III, the retest variability increased substantially with reducing sensitivity. Corresponding increases with SAP V, Matrix, and Motion perimetry were considerably smaller or absent. With SAP III, sensitivity explained 22% of the retest variability (r(2)), whereas corresponding data for SAP V, Matrix, and Motion perimetry were 12%, 2%, and 2%, respectively. Variability of Matrix and Motion perimetry does not increase as substantially as that of SAP III in damaged areas of the visual field. Increased sampling with the larger stimuli of these techniques is the likely explanation for this finding. These properties may make these stimuli excellent candidates for early detection of visual field progression.

Spectral and Temporal Processing in Rat Posterior Auditory Cortex

PubMed Central

Pandya, Pritesh K.; Rathbun, Daniel L.; Moucha, Raluca; Engineer, Navzer D.; Kilgard, Michael P.

2009-01-01

The rat auditory cortex is divided anatomically into several areas, but little is known about the functional differences in information processing between these areas. To determine the filter properties of rat posterior auditory field (PAF) neurons, we compared neurophysiological responses to simple tones, frequency modulated (FM) sweeps, and amplitude modulated noise and tones with responses of primary auditory cortex (A1) neurons. PAF neurons have excitatory receptive fields that are on average 65% broader than A1 neurons. The broader receptive fields of PAF neurons result in responses to narrow and broadband inputs that are stronger than A1. In contrast to A1, we found little evidence for an orderly topographic gradient in PAF based on frequency. These neurons exhibit latencies that are twice as long as A1. In response to modulated tones and noise, PAF neurons adapt to repeated stimuli at significantly slower rates. Unlike A1, neurons in PAF rarely exhibit facilitation to rapidly repeated sounds. Neurons in PAF do not exhibit strong selectivity for rate or direction of narrowband one octave FM sweeps. These results indicate that PAF, like nonprimary visual fields, processes sensory information on larger spectral and longer temporal scales than primary cortex. PMID:17615251

Neurophysiology of action anticipation in athletes: A systematic review.

PubMed

Smith, Daniel M

2016-01-01

The purpose of this study was to provide a systematic review of action anticipation studies using functional neuroimaging or brain stimulation during a sport-specific anticipation task. A total of 15 studies from 2008 to 2014 were evaluated and are reported in four sections: expert-novice samples, action anticipation tasks, neuroimaging and stimulation techniques, and key findings. Investigators examined a wide range of action anticipation scenarios specific to eight different sports and utilized functional magnetic resonance imaging (fMRI), electroencephalogram (EEG), and transcranial magnetic stimulation (TMS). Expert-novice comparisons were commonly used to investigate differences in action anticipation performance and neurophysiology. Experts tended to outperform novices, and an extensive array of brain structures were reported to be involved differently for experts and novices during action anticipation. However, these neurophysiological findings were generally inconsistent across the studies reviewed. The discussion focuses on strengths and four key limitations. The conclusion posits remaining questions and recommendations for future research. Copyright © 2015 Elsevier Ltd. All rights reserved.

The neurophysiological effects of dry needling in patients with upper trapezius myofascial trigger points: study protocol of a controlled clinical trial

PubMed Central

Abbaszadeh-Amirdehi, Maryam; Ansari, Noureddin Nakhostin; Naghdi, Soofia; Olyaei, Gholamreza; Nourbakhsh, Mohammad Reza

2013-01-01

Introduction Dry needling (DN) is an effective method for the treatment of myofascial trigger points (MTrPs). There is no report on the neurophysiological effects of DN in patients with MTrPs. The aim of the present study will be to assess the immediate neurophysiological efficacy of deep DN in patients with upper trapezius MTrPs. Methods and analysis A prospective, controlled clinical trial was designed to include patients with upper trapezius MTrPs and volunteered healthy participants to receive one session of DN. The primary outcome measures are neuromuscular junction response and sympathetic skin response. The secondary outcomes are pain intensity and pressure pain threshold. Data will be collected at baseline and immediately after intervention. Ethics and dissemination This study protocol has been approved by the Research Council, School of Rehabilitation and the Ethics Committee of Tehran University of Medical Sciences. The results of the study will be disseminated in a peer-reviewed journal and presented at international congresses. PMID:23793673

Expectations affect psychological and neurophysiological benefits even after a single bout of exercise.

PubMed

Mothes, Hendrik; Leukel, Christian; Jo, Han-Gue; Seelig, Harald; Schmidt, Stefan; Fuchs, Reinhard

2017-04-01

The study investigated whether typical psychological, physiological, and neurophysiological changes from a single exercise are affected by one's beliefs and expectations. Seventy-six participants were randomly assigned to four groups and saw different multimedia presentations suggesting that the subsequent exercise (moderate 30 min cycling) would result in more or less health benefits (induced expectations). Additionally, we assessed habitual expectations reflecting previous experience and beliefs regarding exercise benefits. Participants with more positive habitual expectations consistently demonstrated both greater psychological benefits (more enjoyment, mood increase, and anxiety reduction) and greater increase of alpha-2 power, assessed with electroencephalography. Manipulating participants' expectations also resulted in largely greater increases of alpha-2 power, but not in more psychological exercise benefits. On the physiological level, participants decreased their blood pressure after exercising, but this was independent of their expectations. These results indicate that habitual expectations in particular affect exercise-induced psychological and neurophysiological changes in a self-fulfilling manner.

A two-channel action-potential generator for testing neurophysiologic data acquisition/analysis systems.

PubMed

Lisiecki, R S; Voigt, H F

1995-08-01

A 2-channel action-potential generator system was designed for use in testing neurophysiologic data acquisition/analysis systems. The system consists of a personal computer controlling an external hardware unit. This system is capable of generating 2 channels of simulated action potential (AP) waveshapes. The AP waveforms are generated from the linear combination of 2 principal-component template functions. Each channel generates randomly occurring APs with a specified rate ranging from 1 to 200 events per second. The 2 trains may be independent of one another or the second channel may be made to be excited or inhibited by the events from the first channel with user-specified probabilities. A third internal channel may be made to excite or inhibit events in both of the 2 output channels with user-specified rate parameters and probabilities. The system produces voltage waveforms that may be used to test neurophysiologic data acquisition systems for recording from 2 spike trains simultaneously and for testing multispike-train analysis (e.g., cross-correlation) software.

Hyperargininemia: 7-month follow-up under sodium benzoate therapy in an Italian child presenting progressive spastic paraparesis, cognitive decline, and novel mutation in ARG1 gene.

PubMed

Baranello, Giovanni; Alfei, Enrico; Martinelli, Diego; Rizzetto, Manuela; Cazzaniga, Fabiana; Dionisi-Vici, Carlo; Gellera, Cinzia; Castellotti, Barbara

2014-09-01

Hyperargininemia due to mutations in ARG1 gene is an autosomal recessive inborn error of metabolism caused by a defect in the final step of the urea cycle. Common clinical presentation is a variable association of progressive spastic paraparesis, epilepsy, and cognitive deficits. We describe the clinical history of an Italian child presenting progressive spastic paraparesis, carrying a new homozygous missense mutation in the ARG1 gene. A detailed clinical, biochemical, and neurophysiological follow-up after 7 months of sodium benzoate therapy is reported. Laboratory findings, gait abnormalities, spastic paraparesis, and electroencephalographic and neurophysiological abnormalities remained quite stable over the follow-up. Conversely, a mild cognitive deterioration has been detected by means of the neuropsychologic assessment. Further longitudinal studies by means of longer follow-up and using clinical, biochemical, radiological, and neurophysiological assessments are needed in such patients to describe natural history and monitor the effects of treatments. Copyright © 2014 Elsevier Inc. All rights reserved.

[Implementation of intraoperative neurophysiologic monitoring in children and adults in secondary and tertiary health care facilities].

PubMed

Maza-Krzeptowsky, Lilia Cristina De la; Romero-Esquiliano, Gabriela; Ramírez-Segura, Eduardo H; Obieta-Cruz, Enrique De; Vega-Sosa, Alfonso; Cárdenas-Mejía, Alexander; Juan-Orta, Daniel San; Castillo-Herrera, Margot; Aguilar-Castillo, Sergio J; Ávila-Ordóñez, Mario U; Cordero-Guzmán, Luz M; Escobar-Cedillo, Rosa E; Fraire-Martínez, María I; Franco-Lira, Marisela O; González-Jaime, José J; Paz-Navarro, Claudia E; Ramos-Peek, Jaime N; Shkurovich-Bialik, Paul; Silva-Cerecedo, Pedro; Tello-Valdés, C Armando; Zavala-Reina, Álvaro A; López-Rodríguez, Jaime; Sosa-García, Ojino

2018-01-01

Intraoperative neurophysiological monitoring (IONM) is a procedure that uses neurophysiological techniques in order to evaluate the motor and sensitive systems during surgeries that endanger the nervous system. The approach, scope, target population, and clinical questions to be answered were defined. A systematic search of the evidence was conducted step by step; during the first stage, clinical practice guidelines were collected, during the second stage systematic reviews were obtained, and during the third stage, clinical trials and observational studies were procured. The MeSH nomenclature and free related terminology were used, with no language restrictions and a 5-10 years frame. The quality of the evidence was graded using the CEPD and SIGN scales. Obtained using the search algorrhythms of 892 documents. Fifty-eight were chosen to be included in the qualitative synthesis. A meta-analysis was not possible due to the heterogeneity of the studies. Eighteen recommendations were issued and will support the adequate use of the IONM. Copyright: © 2018 Permanyer.

Chronic, Wireless Recordings of Large Scale Brain Activity in Freely Moving Rhesus Monkeys

PubMed Central

Schwarz, David A.; Lebedev, Mikhail A.; Hanson, Timothy L.; Dimitrov, Dragan F.; Lehew, Gary; Meloy, Jim; Rajangam, Sankaranarayani; Subramanian, Vivek; Ifft, Peter J.; Li, Zheng; Ramakrishnan, Arjun; Tate, Andrew; Zhuang, Katie; Nicolelis, Miguel A.L.

2014-01-01

Advances in techniques for recording large-scale brain activity contribute to both the elucidation of neurophysiological principles and the development of brain-machine interfaces (BMIs). Here we describe a neurophysiological paradigm for performing tethered and wireless large-scale recordings based on movable volumetric three-dimensional (3D) multielectrode implants. This approach allowed us to isolate up to 1,800 units per animal and simultaneously record the extracellular activity of close to 500 cortical neurons, distributed across multiple cortical areas, in freely behaving rhesus monkeys. The method is expandable, in principle, to thousands of simultaneously recorded channels. It also allows increased recording longevity (5 consecutive years), and recording of a broad range of behaviors, e.g. social interactions, and BMI paradigms in freely moving primates. We propose that wireless large-scale recordings could have a profound impact on basic primate neurophysiology research, while providing a framework for the development and testing of clinically relevant neuroprostheses. PMID:24776634

The MUSE Hubble Ultra Deep Field Survey. VII. Fe II* emission in star-forming galaxies

NASA Astrophysics Data System (ADS)

Finley, Hayley; Bouché, Nicolas; Contini, Thierry; Paalvast, Mieke; Boogaard, Leindert; Maseda, Michael; Bacon, Roland; Blaizot, Jérémy; Brinchmann, Jarle; Epinat, Benoît; Feltre, Anna; Marino, Raffaella Anna; Muzahid, Sowgat; Richard, Johan; Schaye, Joop; Verhamme, Anne; Weilbacher, Peter M.; Wisotzki, Lutz

2017-11-01

Non-resonant Fe II* (λ2365, λ2396, λ2612, λ2626) emission can potentially trace galactic winds in emission and provide useful constraints to wind models. From the 3.15' × 3.15' mosaic of the Hubble Ultra Deep Field (UDF) obtained with the VLT/MUSE integral field spectrograph, we identify a statistical sample of 40 Fe II* emitters and 50 MgIII (λλ2796,2803) emitters from a sample of 271 [O II]λλ3726,3729 emitters with reliable redshifts from z = 0.85-1.50 down to 2 × 10-18 (3σ) ergs s-1 cm-2 (for [O II]), covering the M⋆ range from 108-1011 M⊙. The Fe II* and Mg II emitters follow the galaxy main sequence, but with a clear dichotomy. Galaxies with masses below 109 M⊙ and star formation rates (SFRs) of ≲ 1 M⊙ yr-1 have MgIII emission without accompanying Fe II* emission, whereas galaxies with masses above 1010 M⊙ and SFRs ≳ 10 M⊙ yr-1 have Fe II* emission without accompanying MgIII emission. Between these two regimes, galaxies have both MgIII and Fe II* emission, typically with MgIII P Cygni profiles. Indeed, the MgIII profile shows a progression along the main sequence from pure emission to P Cygni profiles to strong absorption, due to resonant trapping. Combining the deep MUSE data with HST ancillary information, we find that galaxies with pure MgIII emission profiles have lower SFR surface densities than those with either MgIII P Cygni profiles or Fe II* emission. These spectral signatures produced through continuum scattering and fluorescence, MgIII P Cygni profiles and Fe II* emission, are better candidates for tracing galactic outflows than pure MgIII emission, which may originate from HIII regions. We compare the absorption and emission rest-frame equivalent widths for pairs of FeIII transitions to predictions from outflow models and find that the observations consistently have less total re-emission than absorption, suggesting either dust extinction or non-isotropic outflow geometries.

Multivariate cross-frequency coupling via generalized eigendecomposition

PubMed Central

Cohen, Michael X

2017-01-01

This paper presents a new framework for analyzing cross-frequency coupling in multichannel electrophysiological recordings. The generalized eigendecomposition-based cross-frequency coupling framework (gedCFC) is inspired by source-separation algorithms combined with dynamics of mesoscopic neurophysiological processes. It is unaffected by factors that confound traditional CFC methods—such as non-stationarities, non-sinusoidality, and non-uniform phase angle distributions—attractive properties considering that brain activity is neither stationary nor perfectly sinusoidal. The gedCFC framework opens new opportunities for conceptualizing CFC as network interactions with diverse spatial/topographical distributions. Five specific methods within the gedCFC framework are detailed, these are validated in simulated data and applied in several empirical datasets. gedCFC accurately recovers physiologically plausible CFC patterns embedded in noise that causes traditional CFC methods to perform poorly. The paper also demonstrates that spike-field coherence in multichannel local field potential data can be analyzed using the gedCFC framework, which provides significant advantages over traditional spike-field coherence analyses. Null-hypothesis testing is also discussed. DOI: http://dx.doi.org/10.7554/eLife.21792.001 PMID:28117662

The Effective Dynamic Ranges for Glaucomatous Visual Field Progression With Standard Automated Perimetry and Stimulus Sizes III and V.

PubMed

Wall, Michael; Zamba, Gideon K D; Artes, Paul H

2018-01-01

It has been shown that threshold estimates below approximately 20 dB have little effect on the ability to detect visual field progression in glaucoma. We aimed to compare stimulus size V to stimulus size III, in areas of visual damage, to confirm these findings by using (1) a different dataset, (2) different techniques of progression analysis, and (3) an analysis to evaluate the effect of censoring on mean deviation (MD). In the Iowa Variability in Perimetry Study, 120 glaucoma subjects were tested every 6 months for 4 years with size III SITA Standard and size V Full Threshold. Progression was determined with three complementary techniques: pointwise linear regression (PLR), permutation of PLR, and linear regression of the MD index. All analyses were repeated on "censored'' datasets in which threshold estimates below a given criterion value were set to equal the criterion value. Our analyses confirmed previous observations that threshold estimates below 20 dB contribute much less to visual field progression than estimates above this range. These findings were broadly similar with stimulus sizes III and V. Censoring of threshold values < 20 dB has relatively little impact on the rates of visual field progression in patients with mild to moderate glaucoma. Size V, which has lower retest variability, performs at least as well as size III for longitudinal glaucoma progression analysis and appears to have a larger useful dynamic range owing to the upper sensitivity limit being higher.

Neurophysiological correlates of attention behavior in early infancy: Implications for emotion regulation during early childhood

PubMed Central

Perry, Nicole B.; Swingler, Margaret M.; Calkins, Susan D.; Bell, Martha Ann

2015-01-01

Current theoretical conceptualizations of regulatory development suggest that attention processes and emotion regulation processes share common neurophysiological underpinnings and behavioral antecedents such that emotion regulation abilities may build upon early attentional skills. To further elucidate this proposed relationship, we tested whether early neurophysiological processes measured during an attention task in infancy predicted in-task attention behavior, and whether infant's attention behavior was subsequently associated with their ability to regulate emotion in early childhood (N=388). Results indicated that, greater EEG power change (from baseline to task) at medial frontal locations (F3 and F4) during an attention task at 10 months were associated with concurrent observed behavioral attention. Specifically, greater change in EEG power at the right frontal location (F4) was associated with more attention, and greater EEG power at the left frontal location (F3) was associated with less attention, indicating a potential right hemisphere specialization for attention processes already present in the first year of life. In addition, after controlling for 5-month attention behavior, increased behavioral attention at 10-months was negatively associated with children's observed frustration to emotional challenge at age 3. Finally, the indirect effects from 10-month EEG power change at F3 and F4 to 3-year emotion regulation via infants' 10-month behavioral attention were significant, suggesting that infant's attention behavior is one mechanism through which early neurophysiological activity is related to emotion regulation abilities in childhood. PMID:26381926

Cognitive and physical training for the elderly: evaluating outcome efficacy by means of neurophysiological synchronization.

PubMed

Frantzidis, Christos A; Ladas, Aristea-Kiriaki I; Vivas, Ana B; Tsolaki, Magda; Bamidis, Panagiotis D

2014-07-01

Recent neuroscientific research has demonstrated that both healthy and pathological aging induces alterations in the co-operative capacity of neuronal populations in the brain. Both compensatory and neurodegenerative mechanisms contribute to neurophysiological synchronization patterns, which provide a valuable marker for age-related cognitive decline. In this study, we propose that neuroplasticity-based training may facilitate coherent interaction of distant brain regions and consequently enhance cognitive performance in elderly people. If this is true, this would make neurophysiological synchronization a valid outcome measure to assess the efficacy of non-pharmacological interventions to prevent or delay age-related cognitive decline. The present study aims at providing an objective, synchronization-based tool to assess cognitive and/or physical interventions, adopting the notion of Relative Wavelet Entropy. This mathematical model employs a robust and parameter-free synchronization metric. By using data mining techniques, a distance value was computed for all participants so as to quantify the proximity of their individual profile to the mean group synchronization increase. In support of our hypothesis, results showed a significant increase in synchronization, for four electrode pairs, in the intervention group as compared to the active control group. It is concluded that the novel introduction of neurophysiological synchronization features could be used as a valid and reliable outcome measure; while the distance-based analysis could provide a reliable means of evaluating individual benefits. Copyright © 2014 Elsevier B.V. All rights reserved.

Do isolated packaging variables influence consumers' attention and preferences?

PubMed

García-Madariaga, Jesús; Blasco López, Maria-Francisca; Burgos, Ingrit Moya; Virto, Nuria Recuero

2018-04-25

Developments in neuroscience have provided the opportunity to know unconscious consumer reactions and acknowledge direct measures of cognitive constructs like attention. Given the ever-increasing concern over packaging's contribution to creating a positive first impression, the current research seeks to examine consumers' attention and declarative preferences regarding the three main different packaging attributes as isolated variables: images, texts and colours. The experiment exposed participants (N = 40) to 63 stimuli, which were based on modifications of the three main packaging attributes of three products of three different food categories. This study used electroencephalogram (EEG) and eye-tracking (ET) to measure attention, and a declarative test was employed to examine preference. First, the results presented herein show that the presence of visual elements, either images or texts on packages, increased the participants' level of attention. Second, the results reveal that colour modifications do not have a significant effect on participants' neurophysiological attention levels. Third, the results demonstrated that the neurophysiological effects among the participants do not necessarily coincide with their subjective evaluations of preference. Hence, this study increases awareness of the relevance of combining traditional market research tools that rely on explicit consumer responses with neuroscientific techniques. These findings indicate, first of all, that more research is needed to ascertain the extent to which consumers' neurophysiological outcomes correspond to their declarative preferences and second, that neurophysiological methods should be given more attention in research. Copyright © 2018 Elsevier Inc. All rights reserved.

Neurophysiological Correlates of Attentional Fluctuation in Attention-Deficit/Hyperactivity Disorder.

PubMed

Cheung, Celeste H M; McLoughlin, Gráinne; Brandeis, Daniel; Banaschewski, Tobias; Asherson, Philip; Kuntsi, Jonna

2017-05-01

Cognitive performance in attention-deficit/hyperactivity disorder (ADHD) is characterised, in part, by frequent fluctuations in response speed, resulting in high reaction time variability (RTV). RTV captures a large proportion of the genetic risk in ADHD but, importantly, is malleable, improving significantly in a fast-paced, rewarded task condition. Using the temporal precision offered by event-related potentials (ERPs), we aimed to examine the neurophysiological measures of attention allocation (P3 amplitudes) and preparation (contingent negative variation, CNV), and their associations with the fluctuating RT performance and its improvement in ADHD. 93 participants with ADHD and 174 controls completed the baseline and fast-incentive conditions of a four-choice reaction time task, while EEG was simultaneously recorded. Compared to controls, individuals with ADHD showed both increased RTV and reduced P3 amplitudes during performance on the RT task. In the participants with ADHD, attenuated P3 amplitudes were significantly associated with high RTV, and the increase in P3 amplitudes from a slow baseline to a fast-paced, rewarded condition was significantly associated with the RTV decrease. Yet, the individuals with ADHD did not show the same increase in CNV from baseline to fast-incentive condition as observed in controls. ADHD is associated both with a neurophysiological impairment of attention allocation (P3 amplitudes) and an inability to adjust the preparatory state (CNV) in a changed context. Our findings suggest that both neurophysiological and cognitive performance measures of attention are malleable in ADHD, which are potential targets for non-pharmacological interventions.

Laboratory-induced learned helplessness attenuates approach motivation as indexed by posterior versus frontal theta activity.

PubMed

Reznik, Samantha J; Nusslock, Robin; Pornpattananangkul, Narun; Abramson, Lyn Y; Coan, James A; Harmon-Jones, Eddie

2017-08-01

Research suggests that midline posterior versus frontal electroencephalographic (EEG) theta activity (PFTA) may reflect a novel neurophysiological index of approach motivation. Elevated PFTA has been associated with approach-related tendencies both at rest and during laboratory tasks designed to enhance approach motivation. PFTA is sensitive to changes in dopamine signaling within the fronto-striatal neural circuit, which is centrally involved in approach motivation, reward processing, and goal-directed behavior. To date, however, no studies have examined PFTA during a laboratory task designed to reduce approach motivation or goal-directed behavior. Considerable animal and human research supports the hypothesis put forth by the learned helplessness theory that exposure to uncontrollable aversive stimuli decreases approach motivation by inducing a state of perceived uncontrollability. Accordingly, the present study examined the effect of perceived uncontrollability (i.e., learned helplessness) on PFTA. EEG data were collected from 74 participants (mean age = 19.21 years; 40 females) exposed to either Controllable (n = 26) or Uncontrollable (n = 25) aversive noise bursts, or a No-Noise Condition (n = 23). In line with prediction, individuals exposed to uncontrollable aversive noise bursts displayed a significant decrease in PFTA, reflecting reduced approach motivation, relative to both individuals exposed to controllable noise bursts or the No-Noise Condition. There was no relationship between perceived uncontrollability and frontal EEG alpha asymmetry, another commonly used neurophysiological index of approach motivation. Results have implications for understanding the neurophysiology of approach motivation and establishing PFTA as a neurophysiological index of approach-related tendencies.

Impairment of decision making and disruption of synchrony between basolateral amygdala and anterior cingulate cortex in the maternally separated rat.

PubMed

Cao, Bing; Wang, Jun; Zhang, Xu; Yang, Xiangwei; Poon, David Chun-Hei; Jelfs, Beth; Chan, Rosa H M; Wu, Justin Che-Yuen; Li, Ying

2016-12-01

There is considerable evidence to suggest early life experiences, such as maternal separation (MS), play a role in the prevalence of emotional dysregulation and cognitive impairment. At the same time, optimal decision making requires functional integrity between the amygdala and anterior cingulate cortex (ACC), and any dysfunction of this system is believed to induce decision-making deficits. However, the impact of MS on decision-making behavior and the underlying neurophysiological mechanisms have not been thoroughly studied. As such, we consider the impact of MS on the emotional and cognitive functions of rats by employing the open-field test, elevated plus-maze test, and rat gambling task (RGT). Using multi-channel recordings from freely behaving rats, we assessed the effects of MS on the large scale synchrony between the basolateral amygdala (BLA) and the ACC; while also characterizing the relationship between neural spiking activity and the ongoing oscillations in theta frequency band across the BLA and ACC. The results indicated that the MS rats demonstrated anxiety-like behavior. While the RGT showed a decrease in the percentage of good decision-makers, and an increase in the percentage of poor decision-makers. Electrophysiological data revealed an increase in the total power in the theta band of the LFP in the BLA and a decrease in theta power in the ACC in MS rats. MS was also found to disrupt the spike-field coherence of the ACC single unit spiking activity to the ongoing theta oscillations in the BLA and interrupt the synchrony in the BLA-ACC pathway. We provide specific evidence that MS leads to decision-making deficits that are accompanied by alteration of the theta band LFP in the BLA-ACC circuitries and disruption of the neural network integrity. These observations may help revise fundamental notions regarding neurophysiological biomarkers to treat cognitive impairment induced by early life stress. Copyright © 2016 Elsevier Inc. All rights reserved.

Commentary on: Are we overpathologizing everyday life? A tenable blueprint for behavioral addiction research. Can the emerging domain of behavioral addictions bring a new reflection for the field of addictions, by stressing the issue of the context of addiction development?

PubMed

de Timary, Philippe; Philippot, Pierre

2015-09-01

This paper is a commentary to the article entitled: "Are we overpathologizing everyday life? A tenable blueprint for behavioral addiction research", by Billieux, Schimmenti, Khazaal, Maurage and Heeren (2015). In this manuscript, we commented on two aspects developed by the authors. Billieux et al. (2015) propose that the recent development of propositions of behavioral addiction is driven by an unwise application of an addiction model to excessive behaviors and rests on a confirmatory research strategy that does not question the psychological processes underlying the development of the conduct. They also show that applying a process driven strategy leads to a more appropriate description of the reality of the behavior and conduct, in particular by describing a variety of motivations for the excessive behavior, which is central to understanding the nature of the conduct. We believe that this new approach, which is fruitful to the emerging domain of behavioral addictions, could also apply to the domain of addictions in general. The latter is characterized by the application of a generic biological model, largely influenced by animal models, focusing on neurophysiological determinants of addiction. This approach may have decreased the attention paid to dimensions of addictions that are more specifically human. We will firstly briefly argue on the limitation of this neurophysiological addiction model for the field of excessive behavioral conducts. Secondly, we will argue for an approach centered on the differentiation of motivations and on the adaptive dimension of the behavior when it first developed and on the evocation of a transition where the conduct became independent of its original function. The emerging domain of behavioral addictions, where no animal model has been developed so far, may bring a new reflection that may apply to the domain of addictions in general, with a specific attention to human questions.

The local magnetic properties of [MnIII6 CrIII]3+ and [FeIII6 CrIII]3+ single-molecule magnets deposited on surfaces studied by spin-polarized photoemission and XMCD with circularly polarized synchrotron radiation

NASA Astrophysics Data System (ADS)

Heinzmann, U.; Helmstedt, A.; Dohmeier, N.; Müller, N.; Gryzia, A.; Brechling, A.; Hoeke, V.; Krickemeyer, E.; Glaser, T.; Fonin, M.; Bouvron, S.; Leicht, P.; Tietze, T.; Goering, E.; Kuepper, K.

2014-04-01

It is demonstrated that local magnetic moments of single molecule magnets (SMM) normally studied by XMCD at very low temperatures and high magnetic fields can be measured by means of spin-resolved electron emission in the paramagnetic phase at room temperature by use of circularly polarized radiation.

The 235U Prompt Fission Neutron Spectrum in the BR1 Reactor at SCK•CEN

NASA Astrophysics Data System (ADS)

Wagemans, Jan; Malambu, Edouard; Borms, Luc; Fiorito, Luca

2016-02-01

The BR1 research reactor at SCK•CEN has a spherical cavity in the graphite above the reactor core. In this cavity an accurately characterised Maxwellian thermal neutron field is present. Different converters can be loaded in the cavity in order to obtain other types of neutron (and gamma) irradiation fields. Inside the so-called MARK III converter a fast 235U(n,f) prompt fission neutron field can be obtained. With the support of MCNP calculations, irradiations in MARK III can be directly related to the pure 235U(n,f) prompt fission neutron spectrum. For this purpose MARK III spectrum averaged cross sections for the most relevant fluence dosimetry reactions have been determined. A calibration factor for absolute measurements has been determined applying activation dosimetry following ISO/IEC 17025 standards.

Filling gaps in visual motion for target capture

PubMed Central

Bosco, Gianfranco; Delle Monache, Sergio; Gravano, Silvio; Indovina, Iole; La Scaleia, Barbara; Maffei, Vincenzo; Zago, Myrka; Lacquaniti, Francesco

2015-01-01

A remarkable challenge our brain must face constantly when interacting with the environment is represented by ambiguous and, at times, even missing sensory information. This is particularly compelling for visual information, being the main sensory system we rely upon to gather cues about the external world. It is not uncommon, for example, that objects catching our attention may disappear temporarily from view, occluded by visual obstacles in the foreground. Nevertheless, we are often able to keep our gaze on them throughout the occlusion or even catch them on the fly in the face of the transient lack of visual motion information. This implies that the brain can fill the gaps of missing sensory information by extrapolating the object motion through the occlusion. In recent years, much experimental evidence has been accumulated that both perceptual and motor processes exploit visual motion extrapolation mechanisms. Moreover, neurophysiological and neuroimaging studies have identified brain regions potentially involved in the predictive representation of the occluded target motion. Within this framework, ocular pursuit and manual interceptive behavior have proven to be useful experimental models for investigating visual extrapolation mechanisms. Studies in these fields have pointed out that visual motion extrapolation processes depend on manifold information related to short-term memory representations of the target motion before the occlusion, as well as to longer term representations derived from previous experience with the environment. We will review recent oculomotor and manual interception literature to provide up-to-date views on the neurophysiological underpinnings of visual motion extrapolation. PMID:25755637

A model of curved saccade trajectories: spike rate adaptation in the brainstem as the cause of deviation away.

PubMed

Kruijne, Wouter; Van der Stigchel, Stefan; Meeter, Martijn

2014-03-01

The trajectory of saccades to a target is often affected whenever there is a distractor in the visual field. Distractors can cause a saccade to deviate towards their location or away from it. The oculomotor mechanisms that produce deviation towards distractors have been thoroughly explored in behavioral, neurophysiological and computational studies. The mechanisms underlying deviation away, on the other hand, remain unclear. Behavioral findings suggest a mechanism of spatially focused, top-down inhibition in a saccade map, and deviation away has become a tool to investigate such inhibition. However, this inhibition hypothesis has little neuroanatomical or neurophysiological support, and recent findings go against it. Here, we propose that deviation away results from an unbalanced saccade drive from the brainstem, caused by spike rate adaptation in brainstem long-lead burst neurons. Adaptation to stimulation in the direction of the distractor results in an unbalanced drive away from it. An existing model of the saccade system was extended with this theory. The resulting model simulates a wide range of findings on saccade trajectories, including findings that have classically been interpreted to support inhibition views. Furthermore, the model replicated the effect of saccade latency on deviation away, but predicted this effect would be absent with large (400 ms) distractor-target onset asynchrony. This prediction was confirmed in an experiment, which demonstrates that the theory both explains classical findings on saccade trajectories and predicts new findings. Copyright © 2014 Elsevier Inc. All rights reserved.

Filling gaps in visual motion for target capture.

PubMed

Bosco, Gianfranco; Monache, Sergio Delle; Gravano, Silvio; Indovina, Iole; La Scaleia, Barbara; Maffei, Vincenzo; Zago, Myrka; Lacquaniti, Francesco

2015-01-01

A remarkable challenge our brain must face constantly when interacting with the environment is represented by ambiguous and, at times, even missing sensory information. This is particularly compelling for visual information, being the main sensory system we rely upon to gather cues about the external world. It is not uncommon, for example, that objects catching our attention may disappear temporarily from view, occluded by visual obstacles in the foreground. Nevertheless, we are often able to keep our gaze on them throughout the occlusion or even catch them on the fly in the face of the transient lack of visual motion information. This implies that the brain can fill the gaps of missing sensory information by extrapolating the object motion through the occlusion. In recent years, much experimental evidence has been accumulated that both perceptual and motor processes exploit visual motion extrapolation mechanisms. Moreover, neurophysiological and neuroimaging studies have identified brain regions potentially involved in the predictive representation of the occluded target motion. Within this framework, ocular pursuit and manual interceptive behavior have proven to be useful experimental models for investigating visual extrapolation mechanisms. Studies in these fields have pointed out that visual motion extrapolation processes depend on manifold information related to short-term memory representations of the target motion before the occlusion, as well as to longer term representations derived from previous experience with the environment. We will review recent oculomotor and manual interception literature to provide up-to-date views on the neurophysiological underpinnings of visual motion extrapolation.

Electrophysiological indices of surround suppression in humans

PubMed Central

Vanegas, M. Isabel; Blangero, Annabelle

2014-01-01

Surround suppression is a well-known example of contextual interaction in visual cortical neurophysiology, whereby the neural response to a stimulus presented within a neuron's classical receptive field is suppressed by surrounding stimuli. Human psychophysical reports present an obvious analog to the effects seen at the single-neuron level: stimuli are perceived as lower-contrast when embedded in a surround. Here we report on a visual paradigm that provides relatively direct, straightforward indices of surround suppression in human electrophysiology, enabling us to reproduce several well-known neurophysiological and psychophysical effects, and to conduct new analyses of temporal trends and retinal location effects. Steady-state visual evoked potentials (SSVEP) elicited by flickering “foreground” stimuli were measured in the context of various static surround patterns. Early visual cortex geometry and retinotopic organization were exploited to enhance SSVEP amplitude. The foreground response was strongly suppressed as a monotonic function of surround contrast. Furthermore, suppression was stronger for surrounds of matching orientation than orthogonally-oriented ones, and stronger at peripheral than foveal locations. These patterns were reproduced in psychophysical reports of perceived contrast, and peripheral electrophysiological suppression effects correlated with psychophysical effects across subjects. Temporal analysis of SSVEP amplitude revealed short-term contrast adaptation effects that caused the foreground signal to either fall or grow over time, depending on the relative contrast of the surround, consistent with stronger adaptation of the suppressive drive. This electrophysiology paradigm has clinical potential in indexing not just visual deficits but possibly gain control deficits expressed more widely in the disordered brain. PMID:25411464

Image quality of the cat eye measured during retinal ganglion cell experiments.

PubMed

Bonds, A B; Enroth-Cugell, C; Pinto, L H

1972-01-01

1. The modulation transfer function (MTF) of the dioptrics of fifteen cat eyes was determined. The aerial image, formed by the eye of a standard object (a 0.5-1.0 degrees annulus), was photographed. The transmission of the film negative was measured with a scanning microdensitometer to yield the light distribution within the aerial image. Correcting for the double passage, this experimentally determined light distribution and the known object light distribution were used to obtain the MTF, applying Fourier methods. Each MTF was used to calculate the light distribution within the retinal image of stimuli of various geometry used in experiments on retinal ganglion cells in the same eye.2. When the eye was equipped with an artificial pupil of the same size as that used in the neurophysiological experiments (4.0-4.8 mm diam.) the MTF had fallen to 0.5 at 2.43 c/deg. When the pupil was removed the MTF had fallen to 0.5 at a much lower spatial frequency (1.0 c/deg). This shows that even when one uses an artificial pupil too large to provide optimal image quality there is a vast improvement over using no pupil.3. These image quality measurements were prompted by the need to know the actual stimulus image in experiments on the functional organization of the receptive field, a need exemplified in this paper by a few specific physiological results. The full neurophysiological results appear in the next two papers.

Ferrotoroidic ground state in a heterometallic {CrIIIDyIII6} complex displaying slow magnetic relaxation.

PubMed

Vignesh, Kuduva R; Soncini, Alessandro; Langley, Stuart K; Wernsdorfer, Wolfgang; Murray, Keith S; Rajaraman, Gopalan

2017-10-18

Toroidal quantum states are most promising for building quantum computing and information storage devices, as they are insensitive to homogeneous magnetic fields, but interact with charge and spin currents, allowing this moment to be manipulated purely by electrical means. Coupling molecular toroids into larger toroidal moments via ferrotoroidic interactions can be pivotal not only to enhance ground state toroidicity, but also to develop materials displaying ferrotoroidic ordered phases, which sustain linear magneto-electric coupling and multiferroic behavior. However, engineering ferrotoroidic coupling is known to be a challenging task. Here we have isolated a {Cr III Dy III 6 } complex that exhibits the much sought-after ferrotoroidic ground state with an enhanced toroidal moment, solely arising from intramolecular dipolar interactions. Moreover, a theoretical analysis of the observed sub-Kelvin zero-field hysteretic spin dynamics of {Cr III Dy III 6 } reveals the pivotal role played by ferrotoroidic states in slowing down the magnetic relaxation, in spite of large calculated single-ion quantum tunneling rates.

Rewiring the primary somatosensory cortex in carpal tunnel syndrome with acupuncture

PubMed Central

Maeda, Yumi; Kim, Hyungjun; Kettner, Norman; Kim, Jieun; Cina, Stephen; Malatesta, Cristina; Gerber, Jessica; McManus, Claire; Ong-Sutherland, Rebecca; Mezzacappa, Pia; Libby, Alexandra; Mawla, Ishtiaq; Morse, Leslie R.; Kaptchuk, Ted J.; Audette, Joseph

2017-01-01

Abstract Carpal tunnel syndrome is the most common entrapment neuropathy, affecting the median nerve at the wrist. Acupuncture is a minimally-invasive and conservative therapeutic option, and while rooted in a complex practice ritual, acupuncture overlaps significantly with many conventional peripherally-focused neuromodulatory therapies. However, the neurophysiological mechanisms by which acupuncture impacts accepted subjective/psychological and objective/physiological outcomes are not well understood. Eligible patients (n = 80, 65 female, age: 49.3 ± 8.6 years) were enrolled and randomized into three intervention arms: (i) verum electro-acupuncture ‘local’ to the more affected hand; (ii) verum electro-acupuncture at ‘distal’ body sites, near the ankle contralesional to the more affected hand; and (iii) local sham electro-acupuncture using non-penetrating placebo needles. Acupuncture therapy was provided for 16 sessions over 8 weeks. Boston Carpal Tunnel Syndrome Questionnaire assessed pain and paraesthesia symptoms at baseline, following therapy and at 3-month follow-up. Nerve conduction studies assessing median nerve sensory latency and brain imaging data were acquired at baseline and following therapy. Functional magnetic resonance imaging assessed somatotopy in the primary somatosensory cortex using vibrotactile stimulation over three digits (2, 3 and 5). While all three acupuncture interventions reduced symptom severity, verum (local and distal) acupuncture was superior to sham in producing improvements in neurophysiological outcomes, both local to the wrist (i.e. median sensory nerve conduction latency) and in the brain (i.e. digit 2/3 cortical separation distance). Moreover, greater improvement in second/third interdigit cortical separation distance following verum acupuncture predicted sustained improvements in symptom severity at 3-month follow-up. We further explored potential differential mechanisms of local versus distal acupuncture using diffusion tensor imaging of white matter microstructure adjacent to the primary somatosensory cortex. Compared to healthy adults (n = 34, 28 female, 49.7 ± 9.9 years old), patients with carpal tunnel syndrome demonstrated increased fractional anisotropy in several regions and, for these regions we found that improvement in median nerve latency was associated with reduction of fractional anisotropy near (i) contralesional hand area following verum, but not sham, acupuncture; (ii) ipsilesional hand area following local, but not distal or sham, acupuncture; and (iii) ipsilesional leg area following distal, but not local or sham, acupuncture. As these primary somatosensory cortex subregions are distinctly targeted by local versus distal acupuncture electrostimulation, acupuncture at local versus distal sites may improve median nerve function at the wrist by somatotopically distinct neuroplasticity in the primary somatosensory cortex following therapy. Our study further suggests that improvements in primary somatosensory cortex somatotopy can predict long-term clinical outcomes for carpal tunnel syndrome. PMID:28334999

Strain field determination in III-V heteroepitaxy coupling finite elements with experimental and theoretical techniques at the nanoscale

NASA Astrophysics Data System (ADS)

Florini, Nikoletta; Dimitrakopulos, George P.; Kioseoglou, Joseph; Pelekanos, Nikos T.; Kehagias, Thomas

2017-04-01

We are briefly reviewing the current status of elastic strain field determination in III-V heteroepitaxial nanostructures, linking finite elements (FE) calculations with quantitative nanoscale imaging and atomistic calculation techniques. III-V semiconductor nanostructure systems of various dimensions are evaluated in terms of their importance in photonic and microelectronic devices. As elastic strain distribution inside nano-heterostructures has a significant impact on the alloy composition, and thus their electronic properties, it is important to accurately map its components both at the interface plane and along the growth direction. Therefore, we focus on the determination of the stress-strain fields in III-V heteroepitaxial nanostructures by experimental and theoretical methods with emphasis on the numerical FE method by means of anisotropic continuum elasticity (CE) approximation. Subsequently, we present our contribution to the field by coupling FE simulations on InAs quantum dots (QDs) grown on (211)B GaAs substrate, either uncapped or buried, and GaAs/AlGaAs core-shell nanowires (NWs) grown on (111) Si, with quantitative high-resolution transmission electron microscopy (HRTEM) methods and atomistic molecular dynamics (MD) calculations. Full determination of the elastic strain distribution can be exploited for band gap tailoring of the heterostructures by controlling the content of the active elements, and thus influence the emitted radiation.

25 CFR 163.40 - Indian and Alaska Native forestry education assistance.

Code of Federal Regulations, 2011 CFR

2011-04-01

... forestry-related field which could include courses on indigenous culture; and (iii) To create an... technologies as well as native indigenous forestry technologies; (iii) Involve students in projects and...

25 CFR 163.40 - Indian and Alaska Native forestry education assistance.

Code of Federal Regulations, 2012 CFR

2012-04-01

... forestry-related field which could include courses on indigenous culture; and (iii) To create an... technologies as well as native indigenous forestry technologies; (iii) Involve students in projects and...

25 CFR 163.40 - Indian and Alaska Native forestry education assistance.

Code of Federal Regulations, 2013 CFR

2013-04-01

... forestry-related field which could include courses on indigenous culture; and (iii) To create an... technologies as well as native indigenous forestry technologies; (iii) Involve students in projects and...

25 CFR 163.40 - Indian and Alaska Native forestry education assistance.

Code of Federal Regulations, 2014 CFR

2014-04-01

... forestry-related field which could include courses on indigenous culture; and (iii) To create an... technologies as well as native indigenous forestry technologies; (iii) Involve students in projects and...

Voltammetric determination of arsenic in high iron and manganese groundwaters.

PubMed

Gibbon-Walsh, Kristoff; Salaün, Pascal; Uroic, M Kalle; Feldmann, Joerg; McArthur, John M; van den Berg, Constant M G

2011-09-15

Determination of the speciation of arsenic in groundwaters, using cathodic stripping voltammetry (CSV), is severely hampered by high levels of iron and manganese. Experiments showed that the interference is eliminated by addition of EDTA, making it possible to determine the arsenic speciation on-site by CSV. This work presents the CSV method to determine As(III) in high-iron or -manganese groundwaters in the field with only minor sample treatment. The method was field-tested in West-Bengal (India) on a series of groundwater samples. Total arsenic was subsequently determined after acidification to pH 1 by anodic stripping voltammetry (ASV). Comparative measurements by ICP-MS as reference method for total As, and by HPLC for its speciation, were used to corroborate the field data in stored samples. Most of the arsenic (78±0.02%) was found to occur as inorganic As(III) in the freshly collected waters, in accordance with previous studies. The data shows that the modified on-site CSV method for As(III) is a good measure of water contamination with As. The EDTA was also found to be effective in stabilising the arsenic speciation for longterm sample storage at room temperature. Without sample preservation, in water exposed to air and sunlight, the As(III) was found to become oxidised to As(V), and Fe(II) oxidised to Fe(III), removing the As(V) by adsorption on precipitating Fe(III)-hydroxides within a few hours. Copyright © 2011 Elsevier B.V. All rights reserved.

Physicochemical heterogeneity controls on uranium bioreduction rates at the field scale.

PubMed

Li, Li; Gawande, Nitin; Kowalsky, Michael B; Steefel, Carl I; Hubbard, Susan S

2011-12-01

It has been demonstrated in laboratory systems that U(VI) can be reduced to immobile U(IV) by bacteria in natural environments. The ultimate efficacy of bioreduction at the field scale, however, is often challenging to quantify and depends on site characteristics. In this work, uranium bioreduction rates at the field scale are quantified, for the first time, using an integrated approach. The approach combines field data, inverse and forward hydrological and reactive transport modeling, and quantification of reduction rates at different spatial scales. The approach is used to explore the impact of local scale (tens of centimeters) parameters and processes on field scale (tens of meters) system responses to biostimulation treatments and the controls of physicochemical heterogeneity on bioreduction rates. Using the biostimulation experiments at the Department of Energy Old Rifle site, our results show that the spatial distribution of hydraulic conductivity and solid phase mineral (Fe(III)) play a critical role in determining the field-scale bioreduction rates. Due to the dependence on Fe-reducing bacteria, field-scale U(VI) bioreduction rates were found to be largely controlled by the abundance of Fe(III) minerals at the vicinity of the injection wells and by the presence of preferential flow paths connecting injection wells to down gradient Fe(III) abundant areas.

Carbonato-bridged Ni(II)2Ln(III)2 (Ln(III) = Gd(III), Tb(III), Dy(III)) complexes generated by atmospheric CO2 fixation and their single-molecule-magnet behavior: [(μ4-CO3)2{Ni(II)(3-MeOsaltn)(MeOH or H2O)Ln(III)(NO3)}2]·solvent [3-MeOsaltn = N,N'-bis(3-methoxy-2-oxybenzylidene)-1,3-propanediaminato].

PubMed

Sakamoto, Soichiro; Fujinami, Takeshi; Nishi, Koshiro; Matsumoto, Naohide; Mochida, Naotaka; Ishida, Takayuki; Sunatsuki, Yukinari; Re, Nazzareno

2013-06-17

Atmospheric CO2 fixation of [Ni(II)(3-MeOsaltn)(H2O)2]·2.5H2O [3-MeOsaltn = N,N'-bis(3-methoxy-2-oxybenzylidene)-1,3-propanediaminato], Ln(III)(NO3)3·6H2O, and triethylamine occurred in methanol/acetone, giving a first series of carbonato-bridged Ni(II)2Ln(III)2 complexes [(μ4-CO3)2{Ni(II)(3-MeOsaltn)(MeOH)Ln(III)(NO3)}2] (1Gd, 1Tb, and 1Dy). When the reaction was carried out in acetonitrile/water, it gave a second series of complexes [(μ4-CO3)2{Ni(II)(3-MeOsaltn)(H2O)Ln(III)(NO3)}2]·2CH3CN·2H2O (2Gd, 2Tb, and 2Dy). For both series, each Ni(II)2Ln(III)2 structure can be described as two di-μ-phenoxo-bridged Ni(II)Ln(III) binuclear units bridged by two carbonato CO3(2-) units to form a carbonato-bridged (μ4-CO3)2{Ni(II)2Ln(III)2} structure. The high-spin Ni(II) ion has octahedral coordination geometry, and the Ln(III) ion is coordinated by O9 donor atoms from Ni(II)(3-MeOsaltn), bidentate NO3(-), and one and two oxygen atoms of two CO3(2-) ions. The NO3(-) ion for the first series roughly lie on Ln-O(methoxy) bonds and are tilted toward the outside, while for the second series, the two oxygen atoms roughly lie on one of the Ln-O(phenoxy) bonds due to the intramolecular hydrogen bond. The temperature-dependent magnetic susceptibilities indicated a ferromagnetic interaction between the Ni(II) and Ln(III) ions (Ln(III) = Gd(III), Tb(III), Dy(III)) for all of the complexes, with a distinctly different magnetic behavior between the two series in the lowest-temperature region due to the Ln(III)-Ln(III) magnetic interaction and/or different magnetic anisotropies of the Tb(III) or Dy(III) ion. Alternating-current susceptibility measurements under the 0 and 1000 Oe direct-current (dc) bias fields showed no magnetic relaxation for the Ni(II)2Gd(III)2 complexes but exhibited an out-of-phase signal for Ni(II)2Tb(III)2 and Ni(II)2Dy(III)2, indicative of slow relaxation of magnetization. The energy barriers, Δ/kB, for the spin flipping were estimated from the Arrhenius plot to be 12.2(7) and 6.1(3) K for 1Tb and 2Tb, respectively, and 18.1(6) and 14.5(4) K for 1Dy and 2Dy, respectively, under a dc bias field of 1000 Oe. Compound 1Dy showed relatively slow relaxation of magnetization reorientation even at zero dc applied field with Δ/kB = 6.6(4) K.

Dreams and creative problem-solving.

PubMed

Barrett, Deirdre

2017-10-01

Dreams have produced art, music, novels, films, mathematical proofs, designs for architecture, telescopes, and computers. Dreaming is essentially our brain thinking in another neurophysiologic state-and therefore it is likely to solve some problems on which our waking minds have become stuck. This neurophysiologic state is characterized by high activity in brain areas associated with imagery, so problems requiring vivid visualization are also more likely to get help from dreaming. This article reviews great historical dreams and modern laboratory research to suggest how dreams can aid creativity and problem-solving. © 2017 New York Academy of Sciences.

[A multidiscipline clinical and biological approach to the study of psychotic types of autistic spectrum disorders in children].

PubMed

Simashkova, N V; Iakupova, L P; Kliushnik, T P; Koval'-Zaĭtsev, A A

2013-01-01

The current problem of heterogeneity of psychotic types of autistic spectrum disorders (ASD) is reviewed. The authors present results of a multidiscipline psychopathological, pathopsychological, neurophysiological and immunological examination of 87 patients, aged from 3 to 14 years, with psychotic types of ASD: childhood psychosis (CP) and atypical childhood psychosis (ACP). Significant differences in clinical presentations of CP and ACP that were correlated with pathopsychological, neurophysiological and immunological disorders were found. These findings support different nosological entities of these types of ASD.

SOME THOUGHTS ON NEUROPHYSIOLOGICAL BASIS OF YOGA

PubMed Central

Ramamurthi, B.

1981-01-01

Yoga presents the culmination of efforts made by mankind till now control mind and behaviour. It is living science, practiced in an elementary fashion by many in India. While a few perhaps are there who have attained mastery of this science. The background of the derivation and concept of yoga in India is presented followed by a simple exposition of yogic practices and some possible neurophysiologic explanations. Research in yoga will be rewarding as it gives means of exploring and enlarging the functions of the human brain. PMID:22556457

Focal brainstem gliomas

PubMed Central

Sabbagh, Abdulrahman J.; Alaqeel, Ahmed M.

2015-01-01

Improved neuronavigation guidance as well as intraoperative imaging and neurophysiologic monitoring technologies have enhanced the ability of neurosurgeons to resect focal brainstem gliomas. In contrast, diffuse brainstem gliomas are considered to be inoperable lesions. This article is a continuation of an article that discussed brainstem glioma diagnostics, imaging, and classification. Here, we address open surgical treatment of and approaches to focal, dorsally exophytic, and cervicomedullary brainstem gliomas. Intraoperative neuronavigation, intraoperative neurophysiologic monitoring, as well as intraoperative imaging are discussed as adjunctive measures to help render these procedures safer, more acute, and closer to achieving surgical goals. PMID:25864061

Bringing part of the lab to the field: On-site chromium speciation in seawater by electrodeposition of Cr(III)/Cr(VI) on portable coiled-filament assemblies and measurement in the lab by electrothermal, near-torch vaporization sample introduction and inductively coupled plasma-atomic emission spectrometry

NASA Astrophysics Data System (ADS)

Badiei, Hamid R.; McEnaney, Jennifer; Karanassios, Vassili

2012-12-01

A field-deployable electrochemical approach to preconcentration, matrix clean up and selective electrodeposition of Cr(III) and Cr(III) + Cr(VI) in seawater is described. Using portable, battery-operated electrochemical instrumentation, Cr species in seawater were electrodeposited in the field on portable coiled-filament assemblies made from Re. Assemblies with dried residues of Cr(III) or Cr(III) + Cr(VI) on them were transported to the lab for concentration determination by electrothermal, near-torch vaporization (NTV) sample introduction and inductively coupled plasma-atomic emission spectrometry (ICP-AES). Electrodeposition offers selective species deposition, preconcentration and matrix clean up from seawater samples. For selective deposition, free Cr(VI) was electrodeposited at - 0.3 V and Cr(III) + Cr(VI) at - 1.6 V (both vs Ag/AgCl). Interestingly, at 0 V (vs Ag/AgCl) and in the absence of an electrodeposition potential only Cr(VI) was spontaneously and selectively adsorbed on the coil and reasons for this are given. Due to preconcentration afforded by electrodeposition, the detection limits obtained after a 60 s electrodeposition at the voltages stated above using buffered (pH = 4.7) artificial seawater spiked with either Cr(III) or Cr(VI) were 20 pg/mL for Cr(III) and 10 pg/mL for Cr(VI). For comparison, the detection limit for Cr obtained by pipetting directly on the coil 5 μL of diluted standard solution was 500 pg/mL, thus it was concluded that electrodeposition offered 40 to 60 fold improvements. Matrix clean up is required due to the high salt content of seawater and this was addressed by simply rinsing the coil with 18.2 MΩ water without any loss of Cr species. Reasons for this are provided. The method was validated in the lab using buffered artificial seawater and it was used in the field for the first time by sampling seawater, buffering it and immediately electrodepositing Cr species on portable assemblies on-site. Electrodeposition in the field addressed species transformation during sample pre-treatment. Such transformations occur due to sample acidification and may take place during transport and possibly storage prior to analysis. Thus, electrodeposition in the field is more reflective of Cr species concentration at the environmental conditions (e.g., temperature) at the time of sampling. It also opens up the possibility for shipping to the lab portable assemblies with Cr species on them rather than shipping large volumes of sample to the lab, thus also reducing shipping, handling and storage costs.

Effects of Millimeter-Wave Electromagnetic Radiation on the Experimental Model of Migraine.

PubMed

Sivachenko, I B; Medvedev, D S; Molodtsova, I D; Panteleev, S S; Sokolov, A Yu; Lyubashina, O A

2016-02-01

Effects of millimeter-wave electromagnetic radiation (40 GHz frequency, 0.01 mW power) on the spontaneous fi ring of convergent neurons of the spinal trigeminal nucleus and their responses to electrical stimulation of the dura mater were studied in neurophysiological experiments on rats. Irradiation of the area of cutaneous receptive fields of spinal trigeminal nucleus reversibly inhibited both spontaneous discharges and activity induced by electrical stimulation of the dura mater. The second and third exposures to electromagnetic radiation with an interval of 10 min were ineffective. These results suggest that suppression of neuronal excitability in the spinal trigeminal ganglion can be a mechanism of the anti-migraine effects of electromagnetic radiation observed in clinical practice.

Event-related potentials in homosexual and heterosexual men and women: sex-dimorphic patterns in verbal asymmetries and mental rotation.

PubMed

Wegesin, D J

1998-02-01

To elucidate neurobiological factors related to gender and sexual orientation, event-related brain potentials of 20 heterosexual (HT) men, 20 HT women, 20 homosexual (HM) men, and 20 HM women were examined for neurophysiological differences. Cognitive tasks which typically elicit sex differences were administered. A mental rotation (MR) task assessed spatial ability, and a divided-visual-field lexical-decision/semantic monitoring task (LD/SM) assessed verbal ability and relative degrees of language lateralization. Slow wave activity recorded during MR was greater for HT men than for HT women and gay men. N400 asymmetries recorded during the LD/SM task revealed differences between men and women, but no intrasex differences. Copyright 1998 Academic Press.

The repeatability of mean defect with size III and size V standard automated perimetry.

PubMed

Wall, Michael; Doyle, Carrie K; Zamba, K D; Artes, Paul; Johnson, Chris A

2013-02-15

The mean defect (MD) of the visual field is a global statistical index used to monitor overall visual field change over time. Our goal was to investigate the relationship of MD and its variability for two clinically used strategies (Swedish Interactive Threshold Algorithm [SITA] standard size III and full threshold size V) in glaucoma patients and controls. We tested one eye, at random, for 46 glaucoma patients and 28 ocularly healthy subjects with Humphrey program 24-2 SITA standard for size III and full threshold for size V each five times over a 5-week period. The standard deviation of MD was regressed against the MD for the five repeated tests, and quantile regression was used to show the relationship of variability and MD. A Wilcoxon test was used to compare the standard deviations of the two testing methods following quantile regression. Both types of regression analysis showed increasing variability with increasing visual field damage. Quantile regression showed modestly smaller MD confidence limits. There was a 15% decrease in SD with size V in glaucoma patients (P = 0.10) and a 12% decrease in ocularly healthy subjects (P = 0.08). The repeatability of size V MD appears to be slightly better than size III SITA testing. When using MD to determine visual field progression, a change of 1.5 to 4 decibels (dB) is needed to be outside the normal 95% confidence limits, depending on the size of the stimulus and the amount of visual field damage.

The Effective Dynamic Ranges for Glaucomatous Visual Field Progression With Standard Automated Perimetry and Stimulus Sizes III and V

PubMed Central

Zamba, Gideon K. D.; Artes, Paul H.

2018-01-01

Purpose It has been shown that threshold estimates below approximately 20 dB have little effect on the ability to detect visual field progression in glaucoma. We aimed to compare stimulus size V to stimulus size III, in areas of visual damage, to confirm these findings by using (1) a different dataset, (2) different techniques of progression analysis, and (3) an analysis to evaluate the effect of censoring on mean deviation (MD). Methods In the Iowa Variability in Perimetry Study, 120 glaucoma subjects were tested every 6 months for 4 years with size III SITA Standard and size V Full Threshold. Progression was determined with three complementary techniques: pointwise linear regression (PLR), permutation of PLR, and linear regression of the MD index. All analyses were repeated on “censored'' datasets in which threshold estimates below a given criterion value were set to equal the criterion value. Results Our analyses confirmed previous observations that threshold estimates below 20 dB contribute much less to visual field progression than estimates above this range. These findings were broadly similar with stimulus sizes III and V. Conclusions Censoring of threshold values < 20 dB has relatively little impact on the rates of visual field progression in patients with mild to moderate glaucoma. Size V, which has lower retest variability, performs at least as well as size III for longitudinal glaucoma progression analysis and appears to have a larger useful dynamic range owing to the upper sensitivity limit being higher. PMID:29356822

Yoga Therapy and Polyvagal Theory: The Convergence of Traditional Wisdom and Contemporary Neuroscience for Self-Regulation and Resilience

PubMed Central

Sullivan, Marlysa B.; Erb, Matt; Schmalzl, Laura; Moonaz, Steffany; Noggle Taylor, Jessica; Porges, Stephen W.

2018-01-01

Yoga therapy is a newly emerging, self-regulating complementary and integrative healthcare (CIH) practice. It is growing in its professionalization, recognition and utilization with a demonstrated commitment to setting practice standards, educational and accreditation standards, and promoting research to support its efficacy for various populations and conditions. However, heterogeneity of practice, poor reporting standards, and lack of a broadly accepted understanding of the neurophysiological mechanisms involved in yoga therapy limits the structuring of testable hypotheses and clinical applications. Current proposed frameworks of yoga-based practices focus on the integration of bottom-up neurophysiological and top-down neurocognitive mechanisms. In addition, it has been proposed that phenomenology and first person ethical inquiry can provide a lens through which yoga therapy is viewed as a process that contributes towards eudaimonic well-being in the experience of pain, illness or disability. In this article we build on these frameworks, and propose a model of yoga therapy that converges with Polyvagal Theory (PVT). PVT links the evolution of the autonomic nervous system to the emergence of prosocial behaviors and posits that the neural platforms supporting social behavior are involved in maintaining health, growth and restoration. This explanatory model which connects neurophysiological patterns of autonomic regulation and expression of emotional and social behavior, is increasingly utilized as a framework for understanding human behavior, stress and illness. Specifically, we describe how PVT can be conceptualized as a neurophysiological counterpart to the yogic concept of the gunas, or qualities of nature. Similar to the neural platforms described in PVT, the gunas provide the foundation from which behavioral, emotional and physical attributes emerge. We describe how these two different yet analogous frameworks—one based in neurophysiology and the other in an ancient wisdom tradition—highlight yoga therapy’s promotion of physical, mental and social wellbeing for self-regulation and resilience. This parallel between the neural platforms of PVT and the gunas of yoga is instrumental in creating a translational framework for yoga therapy to align with its philosophical foundations. Consequently, yoga therapy can operate as a distinct practice rather than fitting into an outside model for its utilization in research and clinical contexts. PMID:29535617

Evaluation of TV commercials using neurophysiological responses.

PubMed

Yang, Taeyang; Lee, Do-Young; Kwak, Youngshin; Choi, Jinsook; Kim, Chajoong; Kim, Sung-Phil

2015-04-24

In recent years, neuroscientific knowledge has been applied to marketing as a novel and efficient means to comprehend the cognitive and behavioral aspects of consumers. A number of studies have attempted to evaluate media contents, especially TV commercials using various neuroimaging techniques such as electroencephalography (EEG). Yet neurophysiological examination of detailed cognitive and affective responses in viewers is still required to provide practical information to marketers. Here, this study develops a method to analyze temporal patterns of EEG data and extract affective and cognitive indices such as happiness, surprise, and attention for TV commercial evaluation. Twenty participants participated in the study. We developed the neurophysiological indices for TV commercial evaluation using classification model. Specifically, these model-based indices were customized using individual EEG features. We used a video game for developing the index of attention and four video clips for developing indices of happiness and surprise. Statistical processes including one-way analyses of variance (ANOVA) and the cross validation scheme were used to select EEG features for each index. The EEG features were composed of the combinations of spectral power at selected channels from the cross validation for each individual. The Fisher's linear discriminant classifier (FLDA) was used to estimate each neurophysiological index during viewing four different TV commercials. Post hoc behavioral responses of preference, short-term memory, and recall were measured. Behavioral results showed significant differences for all preference, short-term memory rates, and recall rates between commercials, leading to a 'high-ranked' commercial group and a 'low-ranked' group (P < 0.05). Neural estimation of happiness results revealed a significant difference between the high-ranked and the low-ranked commercials in happiness index (P < 0.01). The order of rankings based on happiness and attention matched well with the order of behavioral response rankings. In the elapsed-time analysis of the highest-ranked commercial, we could point to visual and auditory semantic structures of the commercial that induced increases in the happiness index. Our results demonstrated that the neurophysiological indices developed in this study may provide a useful tool for evaluating TV commercials.

Neurophysiological Aspects and their relationship to clinical and functional impairment in patients with Chronic Obstructive Pulmonary Disease

PubMed Central

de Miranda Rocco, Carolina Chiusoli; Sampaio, Luciana Maria Malosá; Stirbulov, Roberto; Corrêa, João Carlos Ferrari

2011-01-01

OBJECTIVE: The purpose was to assess functional (balance L–L and A–P displacement, sit‐to‐stand test (SST) and Tinetti scale – balance and gait) and neurophysiological aspects (patellar and Achilles reflex and strength) relating these responses to the BODE Index. INTRODUCTION: The neurophysiological alterations found in patients with chronic obstructive pulmonary disease (COPD) are associated with the severity of the disease. There is also involvement of peripheral muscle which, in combination with neurophysiological impairment, may further compromise the functional activity of these patients. METHODS: A cross‐sectional study design was used. Twenty‐two patients with moderate to very severe COPD (>60 years) and 16 age‐matched healthy volunteers served as the control group (CG). The subjects performed spirometry and several measures of static and dynamic balance, monosynaptic reflexes, peripheral muscle strength, SST and the 6‐minute walk test. RESULTS: The individuals with COPD had a reduced reflex response, 36.77±3.23 (p<0.05) and 43.54±6.60 (p<0.05), achieved a lower number repetitions on the SST 19.27±3.88 (p<0.05), exhibited lesser peripheral muscle strength on the femoral quadriceps muscle, 24.98±6.88 (p<0.05) and exhibited deficits in functional balance and gait on the Tinetti scale, 26.86±1.69 (p<0.05), compared with the CG. The BODE Index demonstrated correlations with balance assessment (determined by the Tinetti scale), r = 0.59 (p<0.05) and the sit‐to‐stand test, r = 0.78 (p<0.05). CONCLUSIONS: The individuals with COPD had functional and neurophysiological alterations in comparison with the control group. The BODE Index was correlated with the Tinetti scale and the SST. Both are functional tests, easy to administer, low cost and feasible, especially the SST. These results suggest a worse prognosis; however, more studies are needed to identify the causes of these changes and the repercussions that could result in their activities of daily living. PMID:21437448

Comparison of pain neurophysiology knowledge among health sciences students: a cross-sectional study.

PubMed

Adillón, Cristina; Lozano, Èrik; Salvat, Isabel

2015-10-22

A key tool for use in approaching chronic pain treatment is educating patients to reconceptualize pain. Thus, health professionals are fundamental to the transmission of pain information to patients. Because their understanding of pain is acquired during the educational process, the aim of this study was to compare the knowledge about pain neurophysiology in first and final-year students from three different health science programs at a single University to determine their gain in knowledge using a well-known questionnaire designed to evaluate the understanding of pain. The Neurophysiology of Pain Questionnaire (19 closed-ended questions) was administered to students in their first and final years of study in Medicine, Physiotherapy, or Nutrition. The percentage of correct responses was determined and comparisons of the results were analyzed between the programs as well as between the first and final years of study within each program. For all tests, p-values were two-sided, and results with p-values below 0.05 were considered statistically significant. The participation rate was greater than 51% (n = 285). The mean percentage of correct responses, reported as mean (SD), among the first year students was 42.14 (12.23), without significant statistical differences detected between the programs. The mean percentages of correct responses for students in their final year were as follows: Medicine, 54.38 (13.87); Physiotherapy, 68.92 (16.22); Nutrition, 42.34 (10.11). We found statistically significant differences among all three programs and between the first and final years in Medicine and Physiotherapy. A question-by-question analysis showed that the percentage of correct responses for questions related to the biopsychosocial aspects of pain was higher for students in Physiotherapy than those in Medicine. Students in their final years of Medicine and Physiotherapy programs know more about the neurophysiology of pain than students in their first years of these programs, however there are some questions where first years students have better results. Physiotherapy students have greater knowledge of neurophysiology of pain than Medicine students, especially the biopsychosocial aspects. Even so, their understanding may not be sufficient and does not guarantee an approach to chronic pain that will help patients reconceptualize their pain.

Development of III-Nitride Based THz Inter-Subband Lasers

DTIC Science & Technology

2009-09-30

tested both resonant tunneling diodes and quantum well infrared photodetectors in order to investigate quantum transport in III-Nitrides. Based on the...and tested both resonant tunneling diodes and quantum well infrared photodetectors in order to investigate quantum transport in III- Nitrides. Based...strain on bandstructure and piezo-as well as spontaneous- electric fields. Interband photoluminescence and intersubband absorption measurements were

Timing, timing, timing: Fast decoding of object information from intracranial field potentials in human visual cortex

PubMed Central

Liu, Hesheng; Agam, Yigal; Madsen, Joseph R.; Kreiman, Gabriel

2010-01-01

Summary The difficulty of visual recognition stems from the need to achieve high selectivity while maintaining robustness to object transformations within hundreds of milliseconds. Theories of visual recognition differ in whether the neuronal circuits invoke recurrent feedback connections or not. The timing of neurophysiological responses in visual cortex plays a key role in distinguishing between bottom-up and top-down theories. Here we quantified at millisecond resolution the amount of visual information conveyed by intracranial field potentials from 912 electrodes in 11 human subjects. We could decode object category information from human visual cortex in single trials as early as 100 ms post-stimulus. Decoding performance was robust to depth rotation and scale changes. The results suggest that physiological activity in the temporal lobe can account for key properties of visual recognition. The fast decoding in single trials is compatible with feed-forward theories and provides strong constraints for computational models of human vision. PMID:19409272

Reductionism in the comments and autobiographical accounts of prominent psychologists.

PubMed

Martin, Jack; Dawda, Darek

2002-01-01

Many of the researchers in the field of psychological science use strategies and methods in which human actions and experiences are reduced to behavioral contingencies, statistical regularities, neurophysiological states and processes, and computational functions and models. However, many psychologists talk readily and easily about how their research might assist human agents to solve problems, cope, make decisions, self-regulate, and more generally "make a difference" and "take control." The authors considered informally selected comments by several eminent psychologists, and more formally, 73 autobiographical accounts of prominent psychologists to see what could be learned about the attitudes of these psychologists toward reductionism in their own work and in the field of psychology in general. In interpreting these comments and accounts, the authors posit a gap between many psychologists' contemplation of their work and their actual research practices. The authors also suggest that such a gap may be related to psychologists' educational experiences and their scholarly and professional socialization, as well as to their subdisciplinary attachments and contexts.

Chemical magnetoreception in birds: The radical pair mechanism

PubMed Central

Rodgers, Christopher T.; Hore, P. J.

2009-01-01

Migratory birds travel vast distances each year, finding their way by various means, including a remarkable ability to perceive the Earth's magnetic field. Although it has been known for 40 years that birds possess a magnetic compass, avian magnetoreception is poorly understood at all levels from the primary biophysical detection events, signal transduction pathways and neurophysiology, to the processing of information in the brain. It has been proposed that the primary detector is a specialized ocular photoreceptor that plays host to magnetically sensitive photochemical reactions having radical pairs as fleeting intermediates. Here, we present a physical chemist's perspective on the “radical pair mechanism” of compass magnetoreception in birds. We outline the essential chemical requirements for detecting the direction of an Earth-strength ≈50 μT magnetic field and comment on the likelihood that these might be satisfied in a biologically plausible receptor. Our survey concludes with a discussion of cryptochrome, the photoactive protein that has been put forward as the magnetoreceptor molecule. PMID:19129499

A neural model of motion processing and visual navigation by cortical area MST.

PubMed

Grossberg, S; Mingolla, E; Pack, C

1999-12-01

Cells in the dorsal medial superior temporal cortex (MSTd) process optic flow generated by self-motion during visually guided navigation. A neural model shows how interactions between well-known neural mechanisms (log polar cortical magnification, Gaussian motion-sensitive receptive fields, spatial pooling of motion-sensitive signals and subtractive extraretinal eye movement signals) lead to emergent properties that quantitatively simulate neurophysiological data about MSTd cell properties and psychophysical data about human navigation. Model cells match MSTd neuron responses to optic flow stimuli placed in different parts of the visual field, including position invariance, tuning curves, preferred spiral directions, direction reversals, average response curves and preferred locations for stimulus motion centers. The model shows how the preferred motion direction of the most active MSTd cells can explain human judgments of self-motion direction (heading), without using complex heading templates. The model explains when extraretinal eye movement signals are needed for accurate heading perception, and when retinal input is sufficient, and how heading judgments depend on scene layouts and rotation rates.

Current understanding on the neurophysiology of behavioral thermoregulation

PubMed Central

Almeida, Maria Camila; Vizin, Robson Cristiano Lillo; Carrettiero, Daniel Carneiro

2015-01-01

Temperature influence on the physiology and biochemistry of living organisms has long been recognized, which propels research in the field of thermoregulation. With the cloning and characterization of the transient receptor potential (TRP) ion channels as the principal temperature sensors of the mammalian somatosensory neurons, the understanding, at a molecular level, of thermosensory and thermoregulatory mechanisms became promising. Because thermal environment can be extremely hostile (temperature range on earth's surface is from ∼ −69°C to 58°C), living organisms developed an array of thermoregulatory strategies to guarantee survival, which include both autonomic mechanisms, which aim at increasing or decreasing heat exchange between body, and ambient and behavioral strategies. The knowledge regarding neural mechanisms involved in autonomic thermoregulatory strategies has progressed immensely compared to the knowledge on behavioral thermoregulation. This review aims at collecting the up-to-date knowledge on the neural basis for behavioral thermoregulation in mammals in order to point out perspectives and deployment of this research field. PMID:27227068

Frequency-dependent response of SI RA-class neurons to vibrotactile stimulation of the receptive field.

PubMed

Whitsel, B L; Kelly, E F; Xu, M; Tommerdahl, M; Quibrera, M

2001-01-01

Three types of experiment were carried out on anesthetized monkeys and cats. In the first, spike discharge activity of rapidly adapting (RA) SI neurons was recorded extracellularly during the application of different frequencies of vibrotactile stimulation to the receptive field (RF). The second used the same stimulus conditions to study the response of RA-I (RA) cutaneous mechanoreceptive afferents. The third used optical intrinsic signal (OIS) imaging and extracellular neurophysiological recording methods together, in the same sessions, to evaluate the relationship between the SI optical and RA neuron spike train responses to low- vs high-frequency stimulation of the same skin site. RA afferent entrainment was high at all frequencies of stimulation. In contrast, SI RA neuron entrainment was much lower on average, and was strongly frequency-dependent, declining in near-linear fashion from 6 to 200 Hz. Even at 200 Hz, however, unambiguous frequency-following responses were present in the spike train activity of som

Neurophysiological correlates of attention behavior in early infancy: Implications for emotion regulation during early childhood.

PubMed

Perry, Nicole B; Swingler, Margaret M; Calkins, Susan D; Bell, Martha Ann

2016-02-01

Current theoretical conceptualizations of regulatory development suggest that attention processes and emotion regulation processes share common neurophysiological underpinnings and behavioral antecedents such that emotion regulation abilities may build on early attentional skills. To further elucidate this proposed relationship, we tested whether early neurophysiological processes measured during an attention task in infancy predicted in-task attention behavior and whether infants' attention behavior was subsequently associated with their ability to regulate emotion during early childhood (N=388). Results indicated that greater electroencephalogram (EEG) power change (from baseline to task) at medial frontal locations (F3 and F4) during an attention task at 10months of age was associated with concurrent observed behavioral attention. Specifically, greater change in EEG power at the right frontal location (F4) was associated with more attention and greater EEG power at the left frontal location (F3) was associated with less attention, indicating a potential right hemisphere specialization for attention processes already present during the first year of life. In addition, after controlling for 5-month attention behavior, increased behavioral attention at 10months was negatively associated with children's observed frustration to emotional challenge at 3years of age. Finally, the indirect effects from 10-month EEG power change at F3 and F4 to 3-year emotion regulation via infants' 10-month behavioral attention were significant, suggesting that infants' attention behavior is one mechanism through which early neurophysiological activity is related to emotion regulation abilities during childhood. Copyright © 2015 Elsevier Inc. All rights reserved.

Clinical and neurophysiological changes after targeted intrathecal injections of bone marrow stem cells in a C3 tetraplegic subject.

PubMed

Santamaria, Andrea Jimena; Benavides, Francisco D; DiFede, Darcy L; Khan, Aisha; Pujol, Marietsy V; Dietrich, W Dalton; Marttos, Antonio; Green, Barth A; Hare, Joshua M; Guest, James

2018-05-23

High-level quadriplegia is a devastating condition with limited treatment options. Bone marrow derived stem cells (BMSCs) are reported to have immunomodulatory and neurotrophic effects in spinal cord injury (SCI). We report a subject with complete C2 SCI who received 3 anatomically targeted intrathecal infusions of BMSCs under a single-patient expanded access IND. She underwent intensive physical therapy and was followed for over 2 years. At end-point, her AIS grade improved from A to B and she recovered focal pressure touch sensation over several body areas. We conducted serial neurophysiological testing to monitor changes in residual connectivity. Motor, sensory and autonomic system testing included MEPs, SSEPs, EMG recordings, F waves, galvanic skin responses and tilt-table responses. The quality and magnitude of voluntary EMG activations increased over time but remained below the threshold of clinically obvious movement. Unexpectedly, at 14 months post-injury deep inspiratory maneuvers triggered respiratory-like EMG bursting in the biceps and several other muscles. This finding means that connections between respiratory neurons and motor neurons were newly established, or unmasked. We also report serial analysis of MRI, ISNCSCI, pulmonary function, pain scores, CSF cytokines and bladder assessment. As a single case, the linkage of the clinical and neurophysiological changes to either natural history or to the BMSC infusions cannot be resolved. Nevertheless, such detailed neurophysiological assessment of high cervical SCI patients is rarely performed. Our findings indicate that electrophysiology studies are sensitive to define both residual connectivity and new plasticity.

Current and novel insights into the neurophysiology of migraine and its implications for therapeutics.

PubMed

Akerman, Simon; Romero-Reyes, Marcela; Holland, Philip R

2017-04-01

Migraine headache and its associated symptoms have plagued humans for two millennia. It is manifest throughout the world, and affects more than 1/6 of the global population. It is the most common brain disorder, and is characterized by moderate to severe unilateral headache that is accompanied by vomiting, nausea, photophobia, phonophobia, and other hypersensitive symptoms of the senses. While there is still a clear lack of understanding of its neurophysiology, it is beginning to be understood, and it seems to suggest migraine is a disorder of brain sensory processing, characterized by a generalized neuronal hyperexcitability. The complex symptomatology of migraine indicates that multiple neuronal systems are involved, including brainstem and diencephalic systems, which function abnormally, resulting in premonitory symptoms, ultimately evolving to affect the dural trigeminovascular system, and the pain phase of migraine. The migraineur also seems to be particularly sensitive to fluctuations in homeostasis, such as sleep, feeding and stress, reflecting the abnormality of functioning in these brainstem and diencephalic systems. Implications for therapeutic development have grown out of our understanding of migraine neurophysiology, leading to major drug classes, such as triptans, calcitonin gene-related peptide receptor antagonists, and 5-HT 1F receptor agonists, as well as neuromodulatory approaches, with the promise of more to come. The present review will discuss the current understanding of the neurophysiology of migraine, particularly migraine headache, and novel insights into the complex neural networks responsible for associated neurological symptoms, and how interaction of these networks with migraine pain pathways has implications for the development of novel therapeutics. Copyright © 2016 Elsevier Inc. All rights reserved.

Teaching neurophysiology, neuropharmacology, and experimental design using animal models of psychiatric and neurological disorders.

PubMed

Morsink, Maarten C; Dukers, Danny F

2009-03-01

Animal models have been widely used for studying the physiology and pharmacology of psychiatric and neurological diseases. The concepts of face, construct, and predictive validity are used as indicators to estimate the extent to which the animal model mimics the disease. Currently, we used these three concepts to design a theoretical assignment to integrate the teaching of neurophysiology, neuropharmacology, and experimental design. For this purpose, seven case studies were developed in which animal models for several psychiatric and neurological diseases were described and in which neuroactive drugs used to treat or study these diseases were introduced. Groups of undergraduate students were assigned to one of these case studies and asked to give a classroom presentation in which 1) the disease and underlying pathophysiology are described, 2) face and construct validity of the animal model are discussed, and 3) a pharmacological experiment with the associated neuroactive drug to assess predictive validity is presented. After evaluation of the presentations, we found that the students had gained considerable insight into disease phenomenology, its underlying neurophysiology, and the mechanism of action of the neuroactive drug. Moreover, the assignment was very useful in the teaching of experimental design, allowing an in-depth discussion of experimental control groups and the prediction of outcomes in these groups if the animal model were to display predictive validity. Finally, the highly positive responses in the student evaluation forms indicated that the assignment was of great interest to the students. Hence, the currently developed case studies constitute a very useful tool for teaching neurophysiology, neuropharmacology, and experimental design.

Neurophysiology versus clinical genetics in Rett syndrome: A multicenter study.

PubMed

Halbach, Nicky; Smeets, Eric E; Julu, Peter; Witt-Engerström, Ingegerd; Pini, Giorgio; Bigoni, Stefania; Hansen, Stig; Apartopoulos, Flora; Delamont, Robert; van Roozendaal, Kees; Scusa, Maria F; Borelli, Paolo; Candel, Math; Curfs, Leopold

2016-09-01

Many studies have attempted to establish the genotype-phenotype correlation in Rett syndrome (RTT). Cardiorespiratory measurements provide robust objective data, to correlate with each of the different clinical phenotypes. It has important implications for the management and treatment of this syndrome. The aim of this study was to correlate the genotype with the quantitative cardiorespiratory data obtained by neurophysiological measurement combined with a clinical severity score. This international multicenter study was conducted in four European countries from 1999 to 2012. The study cohort consisted of a group of 132 well-defined RTT females aged between 2 and 43 years with extended clinical, molecular, and neurophysiological assessments. Diagnosis of RTT was based on the consensus criteria for RTT and molecular confirmation. Genotype-phenotype analyses of clinical features and cardiorespiratory data were performed after grouping mutations by the same type and localization or having the same putative biological effect on the MeCP2 protein, and subsequently on eight single recurrent mutations. A less severe phenotype was seen in females with CTS, p.R133C, and p.R294X mutations. Autonomic disturbances were present in all females, and not restricted to nor influenced by one specific group or any single recurrent mutation. The objective information from non-invasive neurophysiological evaluation of the disturbed central autonomic control is of great importance in helping to organize the lifelong care for females with RTT. Further research is needed to provide insights into the pathogenesis of autonomic dysfunction, and to develop evidence-based management in RTT. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Neurophysiological processes and functional neuroanatomical structures underlying proactive effects of emotional conflicts.

PubMed

Schreiter, Marie Luise; Chmielewski, Witold; Beste, Christian

2018-07-01

There is a strong inter-relation of cognitive and emotional processes as evidenced by emotional conflict monitoring processes. In the cognitive domain, proactive effects of conflicts have widely been studied; i.e. effects of conflicts in the n-1 trial on trial n. Yet, the neurophysiological processes and associated functional neuroanatomical structures underlying such proactive effects during emotional conflicts have not been investigated. This is done in the current study combining EEG recordings with signal decomposition methods and source localization approaches. We show that an emotional conflict in the n-1 trial differentially influences processing of positive and negative emotions in trial n, but not the processing of conflicts in trial n. The dual competition framework stresses the importance of dissociable 'perceptual' and 'response selection' or cognitive control levels for interactive effects of cognition and emotion. Only once these coding levels were isolated in the neurophysiological data, processes explaining the behavioral effects were detectable. The data show that there is not only a close correspondence between theoretical propositions of the dual competition framework and neurophysiological processes. Rather, processing levels conceptualized in the framework operate in overlapping time windows, but are implemented via distinct functional neuroanatomical structures; the precuneus (BA31) and the insula (BA13). It seems that decoding of information in the precuneus, as well as the integration of information during response selection in the insula is more difficult when confronted with angry facial emotions whenever cognitive control resources have been highly taxed by previous conflicts. Copyright © 2018 Elsevier Inc. All rights reserved.

Behavioral and Neurophysiological Study of Olfactory Perception and Learning in Honeybees

PubMed Central

Sandoz, Jean Christophe

2011-01-01

The honeybee Apis mellifera has been a central insect model in the study of olfactory perception and learning for more than a century, starting with pioneer work by Karl von Frisch. Research on olfaction in honeybees has greatly benefited from the advent of a range of behavioral and neurophysiological paradigms in the Lab. Here I review major findings about how the honeybee brain detects, processes, and learns odors, based on behavioral, neuroanatomical, and neurophysiological approaches. I first address the behavioral study of olfactory learning, from experiments on free-flying workers visiting artificial flowers to laboratory-based conditioning protocols on restrained individuals. I explain how the study of olfactory learning has allowed understanding the discrimination and generalization ability of the honeybee olfactory system, its capacity to grant special properties to olfactory mixtures as well as to retain individual component information. Next, based on the impressive amount of anatomical and immunochemical studies of the bee brain, I detail our knowledge of olfactory pathways. I then show how functional recordings of odor-evoked activity in the brain allow following the transformation of the olfactory message from the periphery until higher-order central structures. Data from extra- and intracellular electrophysiological approaches as well as from the most recent optical imaging developments are described. Lastly, I discuss results addressing how odor representation changes as a result of experience. This impressive ensemble of behavioral, neuroanatomical, and neurophysiological data available in the bee make it an attractive model for future research aiming to understand olfactory perception and learning in an integrative fashion. PMID:22163215

Evolved Late-Type Star FUV Spectra: Mass Loss and Fluorescence

NASA Technical Reports Server (NTRS)

Harper, Graham M.

2005-01-01

This proposal was for a detailed analysis of the far ultraviolet (FUV) photoionizing radiation that provides crucial input physics for mass loss studies, e.g., observations of the flux below 10448, allow us to constrain the Ca II/Ca III balance and make significant progress beyond previous optical studies on stellar mass loss and circumstellar photochemistry. Our targets selection provided good spectral-type coverage required to help unravel the Ca II/Ca III balance as the mass-loss rates increase by over three orders of magnitude from K5 III to M5 III. We also explored the relationship between the FUV radiation field and other UV diagnostics to allow us to empirically estimate the FUV radiation field for the vast majority of stars which are too faint to be observed with FUSE, and to improve upon their uncertain mass-loss rates.

ACQ4: an open-source software platform for data acquisition and analysis in neurophysiology research.

PubMed

Campagnola, Luke; Kratz, Megan B; Manis, Paul B

2014-01-01

The complexity of modern neurophysiology experiments requires specialized software to coordinate multiple acquisition devices and analyze the collected data. We have developed ACQ4, an open-source software platform for performing data acquisition and analysis in experimental neurophysiology. This software integrates the tasks of acquiring, managing, and analyzing experimental data. ACQ4 has been used primarily for standard patch-clamp electrophysiology, laser scanning photostimulation, multiphoton microscopy, intrinsic imaging, and calcium imaging. The system is highly modular, which facilitates the addition of new devices and functionality. The modules included with ACQ4 provide for rapid construction of acquisition protocols, live video display, and customizable analysis tools. Position-aware data collection allows automated construction of image mosaics and registration of images with 3-dimensional anatomical atlases. ACQ4 uses free and open-source tools including Python, NumPy/SciPy for numerical computation, PyQt for the user interface, and PyQtGraph for scientific graphics. Supported hardware includes cameras, patch clamp amplifiers, scanning mirrors, lasers, shutters, Pockels cells, motorized stages, and more. ACQ4 is available for download at http://www.acq4.org.

A quarter-long exercise that introduces general education students to neurophysiology and scientific writing.

PubMed

Krilowicz, B I; Henter, H; Kamhi-Stein, L

1997-06-01

Providing large numbers of general education students with an introduction to science is a challenge. To meet this challenge, a quarter-long neurophysiology project was developed for use in an introductory biology course. The primary goals of this multistep project were to introduce students to the scientific method, scientific writing, on-line scientific bibliographic databases, and the scientific literature, while improving their academic literacy skills. Students began by collecting data on their own circadian rhythms in autonomic, motor, and cognitive function, reliably demonstrating the predicted circadian changes in heart rate, eye-hand coordination, and adding speed. Students wrote a journal-style article using pooled class data. Students were prepared to write the paper by several methods that were designed to improve academic language skills, including a library training exercise, "modeling" of the writing assignment, and drafting of subsections of the paper. This multistep neurophysiology project represents a significant commitment of time by both students and instructors, but produces a valuable finished product and ideally gives introductory students a positive first experience with science.

Linking psychoanalysis with neuroscience: the concept of ego.

PubMed

Rizzolatti, Giacomo; Semi, Antonio Alberto; Fabbri-Destro, Maddalena

2014-03-01

Through his whole life Marc Jeannerod was fascinated by Freud's thinking. His interest in Freud is witnessed by several of his writings in which he expresses interest in building a bridge between psychoanalysis and cognitive neuroscience. Following Jeannerod's ideas we discuss here a fundamental point of Freud's construction, the concept of ego, from a neurophysiological point of view. We maintain that, in order both to act coherently and to have a basic, first person, understanding of the behavior of others, it is necessary to posit the existence of a neurophysiological "motor" ego similar to the "rider" of the Freudian metaphor. We review then a series of neurophysiological findings showing that the systems underlying the organization of action and conscious perception are both mediated by a cortical motor network formed by parieto-frontal circuits. In conclusion, we show that the activity of this network has strong similarities to that postulated by Freud for the conscious part of ego. We also propose that the default-mode network might represent that part of ego that is mostly involved in unconscious processes. © 2013 Published by Elsevier Ltd.

Functional and structural correlates of magnetic resonance patterns in a new in vitro model of cerebral ischemia by transient occlusion of the medial cerebral artery.

PubMed

Breschi, Gian Luca; Librizzi, Laura; Pastori, Chiara; Zucca, Ileana; Mastropietro, Alfonso; Cattalini, Alessandro; de Curtis, Marco

2010-08-01

Magnetic resonance imaging (MRI) during the acute phase of a stroke contributes to recognize ischemic regions and is potentially useful to predict clinical outcome. Yet, the functional significance of early MRI alterations during brain ischemia is not clearly understood. We achieved an experimental study to interpret MRI signals in a novel model of focal ischemia in the in vitro isolated guinea pig brain. By combining neurophysiological and morphological analysis with MR-imaging, we evaluated the suitability of MR to identify ischemic and peri-ischemic regions. Extracellular recordings demonstrated depolarizations in the ischemic core, but not in adjacent areas, where evoked activity was preserved and brief peri-infarct depolarizations occurred. Diffusion-weighted MRI and immunostaining performed after neurophysiological characterization showed changes restricted to the core region. Diffusion-weighted MR alterations did not include the penumbra region characterized by peri-infarct depolarizations. Therefore, by comparing neurophysiological, imaging and anatomical data, we can conclude that DW-MRI underestimates the extension of the tissue damage involved in brain ischemia.

Synthesis and spectral studies of platinum metal complexes of benzoin thiosemicarbazone

NASA Astrophysics Data System (ADS)

Offiong, Offiong E.

1994-11-01

The platinum metal chelates of benzoin thiosemicarbazone obtained with Ru(III), Rh(III), Ir(III), Pd(II) and Pt(II) were prepared from their corresponding halide salts. The complexes were characterized by elemental analysis, conductance measurement, IR, Raman, 1H-NMR, 13C-NMR and UV-visible spectra studies. Various ligand field parameters and nephelauxetic parameters were also calculated. The mode of bonding and the geometry of the ligand environment around the metal ion have been discussed in the light of the available data obtained. Complexes of Ru(III), Rh(III) and Ir(III) are six-coordinate octahedral, while Pd(II) and Pt(II) halide complexes are four-coordinated with halides bridging.

Evaluation of the exchange interaction and crystal fields in a prototype Dy2 SMM

NASA Astrophysics Data System (ADS)

Zhang, Qing; Sarachik, Myriam; Baker, Michael; Chen, Yizhang; Kent, Andrew; Pineda, Eufemio; McInnes, Eric

In order to gain an understanding of the INS and magnetization data obtained for Dy2, the simplest member of a newly synthesized family of dysprosium-based molecular magnets, we report on calculations of the magnetic behavior of a Dy2 cluster with the formula [hqH2][Dy2(hq)4(NO3)3].MeOH. The molecular complex contains one high symmetry Dy(III) ion and one low symmetry Dy(III) ion. Our calculations suggest that exchange coupling between the two ions controls the behavior of the magnetization at low temperature, while the crystal field of the low symmetry Dy(III) ion controls the behavior at higher temperature. A point charge electrostatic model, based on crystallographic coordinates, provides a starting point for the determination of the crystal field. Parameters in these calculations are adjusted to provide best fits to inelastic neutron scattering data (INS) and low temperature magnetometry: the INS measurements access crystal field energies and low temperature magnetization probes the Dy-Dy exchange interaction. Work supported by ARO W911NF-13-1-1025 (CCNY) and NSF-DMR-1309202 (NYU).

Enrichment of Geobacter species in response to stimulation of Fe(III) reduction in sandy aquifer sediments

USGS Publications Warehouse

Snoeyenbos-West, O.L.; Nevin, K.P.; Anderson, R.T.; Lovely, D.R.

2000-01-01

Engineered stimulation of Fe(III) has been proposed as a strategy to enhance the immobilization of radioactive and toxic metals in metal-contaminated subsurface environments. Therefore, laboratory and field studies were conducted to determine which microbial populations would respond to stimulation of Fe(III) reduction in the sediments of sandy aquifers. In laboratory studies, the addition of either various organic electron donors or electron shuttle compounds stimulated Fe(III) reduction and resulted in Geobacter sequences becoming important constituents of the Bacterial 16S rDNA sequences that could be detected with PCR amplification and denaturing gradient gel electrophoresis (DGGE). Quantification of Geobacteraceae sequences with a PCR most-probable-number technique indicated that the extent to which numbers of Geobacter increased was related to the degree of stimulation of Fe(III) reduction. Geothrix species were also enriched in some instances, but were orders of magnitude less numerous than Geobacter species. Shewanella species were not detected, even when organic compounds known to be electron donors for Shewanella species were used to stimulate Fe(III) reduction in the sediments. Geobacter species were also enriched in two field experiments in which Fe(III) reduction was stimulated with the addition of benzoate or aromatic hydrocarbons. The apparent growth of Geobacter species concurrent with increased Fe(III) reduction suggests that Geobacter species were responsible for much of the Fe(III) reduction in all of the stimulation approaches evaluated in three geographically distinct aquifers. Therefore, strategies for subsurface remediation that involve enhancing the activity of indigenous Fe(III)-reducing populations in aquifers should consider the physiological properties of Geobacter species in their treatment design.

WHERE ARE THE LOW-MASS POPULATION III STARS?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ishiyama, Tomoaki; Sudo, Kae; Yokoi, Shingo

2016-07-20

We study the number and the distribution of low-mass Population III (Pop III) stars in the Milky Way. In our numerical model, hierarchical formation of dark matter minihalos and Milky-Way-sized halos are followed by a high-resolution cosmological simulation. We model the Pop III formation in H{sub 2} cooling minihalos without metal under UV radiation of the Lyman–Werner bands. Assuming a Kroupa initial mass function (IMF) from 0.15 to 1.0 M {sub ⊙} for low-mass Pop III stars, as a working hypothesis, we try to constrain the theoretical models in reverse by current and future observations. We find that the survivorsmore » tend to concentrate on the center of halo and subhalos. We also evaluate the observability of Pop III survivors in the Milky Way and dwarf galaxies, and constraints on the number of Pop III survivors per minihalo. The higher latitude fields require lower sample sizes because of the high number density of stars in the galactic disk, the required sample sizes are comparable in the high- and middle-latitude fields by photometrically selecting low-metallicity stars with optimized narrow-band filters, and the required number of dwarf galaxies to find one Pop III survivor is less than 10 at <100 kpc for the tip of red giant stars. Provided that available observations have not detected any survivors, the formation models of low-mass Pop III stars with more than 10 stars per minihalo are already excluded. Furthermore, we discuss the way to constrain the IMF of Pop III stars at a high mass range of ≳10 M {sub ⊙}.« less

Neurophysiological mechanisms in acceptance and commitment therapy in opioid-addicted patients with chronic pain.

PubMed

Smallwood, Rachel F; Potter, Jennifer S; Robin, Donald A

2016-04-30

Acceptance and Commitment Therapy (ACT) has been effectively utilized to treat both chronic pain and substance use disorder independently. Given these results and the vital need to treat the comorbidity of the two disorders, a pilot ACT treatment was implemented in individuals with comorbid chronic pain and opioid addiction. This pilot study supported using neurophysiology to characterize treatment effects and revealed that, following ACT, participants with this comorbidity exhibited reductions in brain activation due to painful stimulus and in connectivity at rest. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The mirror neuron system and the consequences of its dysfunction.

PubMed

Iacoboni, Marco; Dapretto, Mirella

2006-12-01

The discovery of premotor and parietal cells known as mirror neurons in the macaque brain that fire not only when the animal is in action, but also when it observes others carrying out the same actions provides a plausible neurophysiological mechanism for a variety of important social behaviours, from imitation to empathy. Recent data also show that dysfunction of the mirror neuron system in humans might be a core deficit in autism, a socially isolating condition. Here, we review the neurophysiology of the mirror neuron system and its role in social cognition and discuss the clinical implications of mirror neuron dysfunction.

Decreased sound tolerance: hyperacusis, misophonia, diplacousis, and polyacousis.

PubMed

Jastreboff, Pawel J; Jastreboff, Margaret M

2015-01-01

Definitions, potential mechanisms, and treatments for decreased sound tolerance, hyperacusis, misophonia, and diplacousis are presented with an emphasis on the associated physiologic and neurophysiological processes and principles. A distinction is made between subjects who experience these conditions versus patients who suffer from them. The role of the limbic and autonomic nervous systems and other brain systems involved in cases of bothersome decreased sound tolerance is stressed. The neurophysiological model of tinnitus is outlined with respect to how it may contribute to our understanding of these phenomena and their treatment. © 2015 Elsevier B.V. All rights reserved.

Neuroethics vs neurophysiologically and neuropsychologically uninformed influences in child-rearing, education, emerging hunter-gatherers, and artificial intelligence models of the brain.

PubMed

Pontius, A A

1993-04-01

Potentially negative long-term consequences in four areas are emphasized, if specific neuromaturational, neurophysiological, and neuropsychological facts within a neurodevelopmental and ecological context are neglected in normal functional levels of child development and maturational lag of the frontal lobe system in "Attention Deficit Disorder," in education (reading/writing and arithmetic), in assessment of cognitive functioning in hunter-gatherer populations, specifically modified in the service of their survival, and in constructing computer models of the brain, neglecting consciousness and intentionality as criticized recently by Searle.

Field Potential Oscillations in the Bed Nucleus of the Stria Terminalis Correlate with Compulsion in a Rat Model of Obsessive-Compulsive Disorder.

PubMed

Wu, Hemmings; Tambuyzer, Tim; Nica, Ioana; Deprez, Marjolijn; van Kuyck, Kris; Aerts, Jean-Marie; Van Huffel, Sabine; Nuttin, Bart

2016-09-28

The bed nucleus of the stria terminalis (BNST) is implicated in anxiety and reward processing, both of which are associated with obsessive-compulsive disorder (OCD). Specific neuronal groups in the BNST related to anxiety and reward have been identified, but quantitative data about the information carried by local field potential (LFP) signals in this area during obsession/compulsion are lacking. Here we investigate the BNST LFP in the schedule-induced polydipsia, an animal model of OCD. We implanted electrodes bilaterally in the BNST and random control brain regions in 32 male Wistar rats, and recorded corresponding LFP during compulsive and noncompulsive behavior. We first applied high-frequency (100 Hz) electrical stimulation through the implanted electrodes and analyzed its effects on compulsive behavior. We then performed time-frequency analysis of LFPs and statistically compared the normalized power of δ (1-4 Hz), θ (4-8 Hz), α (8-12 Hz), β (12-30 Hz), and lower γ (30-45 Hz) bands between different groups. Our data showed that the normalized δ, β, and γ powers in the right BNST were specifically correlated with compulsive behaviors. δ and γ oscillations increased and decreased during the initiation phase of compulsion, respectively, whereas β increased after compulsion stopped. Moreover, the effect of BNST electrical stimulation, in terms of suppression of compulsion, was significantly correlated with the percentage change of these bands during compulsion. Our research reveals potential biomarkers and underlying neurophysiological mechanisms of compulsion and warrants further assessment of the use of LFP for closed-loop neuromodulation in OCD. Although specific neuronal groups in the bed nucleus of the stria terminalis (BNST) related to anxiety and reward circuitries have been identified, psychopathological information carried by local field potentials in the BNST has not yet been described. We discovered that normalized powers of the right BNST δ, β, and γ oscillations were highly correlated with compulsion. Specifically, δ and γ oscillations increased and decreased during the initiation phase of compulsion, respectively, whereas β increased after compulsion stopped. Such correlations were not found in other parts of the brain during compulsion, or in the BNST during noncompulsive behavior. Current findings reveal real-time neurophysiological biomarkers of compulsion and warrant further assessment of the use of local field potentials for closed-loop neuromodulation for OCD. Copyright © 2016 the authors 0270-6474/16/3610051-10$15.00/0.

Effect of weak magnetic field on arsenate and arsenite removal from water by zerovalent iron: an XAFS investigation.

PubMed

Sun, Yuankui; Guan, Xiaohong; Wang, Jianmin; Meng, Xiaoguang; Xu, Chunhua; Zhou, Gongming

2014-06-17

In this study, a weak magnetic field (WMF), superimposed with a permanent magnet, was utilized to improve ZVI corrosion and thereby enhance As(V)/As(III) removal by ZVI at pHini 3.0-9.0. The experiment with real arsenic-bearing groundwater revealed that WMF could greatly improve arsenic removal by ZVI even in the presence of various cations and anions. The WMF-induced improvement in As(V)/As(III) removal by ZVI should be primarily associated with accelerated ZVI corrosion, as evidenced by the pH variation, Fe(2+) release, and the formation of corrosion products as characterized with X-ray absorption fine structure spectroscopy. The arsenic species analysis in solution/solid phases at pHini 3.0 revealed that As(III) oxidation to As(V) in aqueous phase preceded its subsequent sequestration by the newly formed iron (hydr)oxides. However, both As(V) adsorption following As(III) oxidation to As(V) in solution and As(III) adsorption preceding its conversion to As(V) in solid phase were observed at pHini 5.0-9.0. The application of WMF accelerated the transformation of As(III) to As(V) in both aqueous and solid phases at pHini 5.0-9.0 and enhanced the oxidation of As(III) to As(V) in solution at pHini 3.0.

Using the Change Manager Model for the Hippocampal System to Predict Connectivity and Neurophysiological Parameters in the Perirhinal Cortex

PubMed Central

Coward, L. Andrew; Gedeon, Tamas D.

2016-01-01

Theoretical arguments demonstrate that practical considerations, including the needs to limit physiological resources and to learn without interference with prior learning, severely constrain the anatomical architecture of the brain. These arguments identify the hippocampal system as the change manager for the cortex, with the role of selecting the most appropriate locations for cortical receptive field changes at each point in time and driving those changes. This role results in the hippocampal system recording the identities of groups of cortical receptive fields that changed at the same time. These types of records can also be used to reactivate the receptive fields active during individual unique past events, providing mechanisms for episodic memory retrieval. Our theoretical arguments identify the perirhinal cortex as one important focal point both for driving changes and for recording and retrieving episodic memories. The retrieval of episodic memories must not drive unnecessary receptive field changes, and this consideration places strong constraints on neuron properties and connectivity within and between the perirhinal cortex and regular cortex. Hence the model predicts a number of such properties and connectivity. Experimental test of these falsifiable predictions would clarify how change is managed in the cortex and how episodic memories are retrieved. PMID:26819594

Decoding the cortical transformations for visually guided reaching in 3D space.

PubMed

Blohm, Gunnar; Keith, Gerald P; Crawford, J Douglas

2009-06-01

To explore the possible cortical mechanisms underlying the 3-dimensional (3D) visuomotor transformation for reaching, we trained a 4-layer feed-forward artificial neural network to compute a reach vector (output) from the visual positions of both the hand and target viewed from different eye and head orientations (inputs). The emergent properties of the intermediate layers reflected several known neurophysiological findings, for example, gain field-like modulations and position-dependent shifting of receptive fields (RFs). We performed a reference frame analysis for each individual network unit, simulating standard electrophysiological experiments, that is, RF mapping (unit input), motor field mapping, and microstimulation effects (unit outputs). At the level of individual units (in both intermediate layers), the 3 different electrophysiological approaches identified different reference frames, demonstrating that these techniques reveal different neuronal properties and suggesting that a comparison across these techniques is required to understand the neural code of physiological networks. This analysis showed fixed input-output relationships within each layer and, more importantly, within each unit. These local reference frame transformation modules provide the basic elements for the global transformation; their parallel contributions are combined in a gain field-like fashion at the population level to implement both the linear and nonlinear elements of the 3D visuomotor transformation.

Emission Patterns of Solar Type III Radio Bursts: Stereoscopic Observations

NASA Technical Reports Server (NTRS)

Thejappa, G.; MacDowall, R.; Bergamo, M.

2012-01-01

Simultaneous observations of solar type III radio bursts obtained by the STEREO A, B, and WIND spacecraft at low frequencies from different vantage points in the ecliptic plane are used to determine their directivity. The heliolongitudes of the sources of these bursts, estimated at different frequencies by assuming that they are located on the Parker spiral magnetic field lines emerging from the associated active regions into the spherically symmetric solar atmosphere, and the heliolongitudes of the spacecraft are used to estimate the viewing angle, which is the angle between the direction of the magnetic field at the source and the line connecting the source to the spacecraft. The normalized peak intensities at each spacecraft Rj = Ij /[Sigma]Ij (the subscript j corresponds to the spacecraft STEREO A, B, and WIND), which are defined as the directivity factors are determined using the time profiles of the type III bursts. It is shown that the distribution of the viewing angles divides the type III bursts into: (1) bursts emitting into a very narrow cone centered around the tangent to the magnetic field with angular width of approximately 2 deg and (2) bursts emitting into a wider cone with angular width spanning from [approx] -100 deg to approximately 100 deg. The plots of the directivity factors versus the viewing angles of the sources from all three spacecraft indicate that the type III emissions are very intense along the tangent to the spiral magnetic field lines at the source, and steadily fall as the viewing angles increase to higher values. The comparison of these emission patterns with the computed distributions of the ray trajectories indicate that the intense bursts visible in a narrow range of angles around the magnetic field directions probably are emitted in the fundamental mode, whereas the relatively weaker bursts visible to a wide range of angles are probably emitted in the harmonic mode.

The range of attraction for light traps catching Culicoides biting midges (Diptera: Ceratopogonidae)

PubMed Central

2013-01-01

Background Culicoides are vectors of e.g. bluetongue virus and Schmallenberg virus in northern Europe. Light trapping is an important tool for detecting the presence and quantifying the abundance of vectors in the field. Until now, few studies have investigated the range of attraction of light traps. Methods Here we test a previously described mathematical model (Model I) and two novel models for the attraction of vectors to light traps (Model II and III). In Model I, Culicoides fly to the nearest trap from within a fixed range of attraction. In Model II Culicoides fly towards areas with greater light intensity, and in Model III Culicoides evaluate light sources in the field of view and fly towards the strongest. Model II and III incorporated the directionally dependent light field created around light traps with fluorescent light tubes. All three models were fitted to light trap collections obtained from two novel experimental setups in the field where traps were placed in different configurations. Results Results showed that overlapping ranges of attraction of neighboring traps extended the shared range of attraction. Model I did not fit data from any of the experimental setups. Model II could only fit data from one of the setups, while Model III fitted data from both experimental setups. Conclusions The model with the best fit, Model III, indicates that Culicoides continuously evaluate the light source direction and intensity. The maximum range of attraction of a single 4W CDC light trap was estimated to be approximately 15.25 meters. The attraction towards light traps is different from the attraction to host animals and thus light trap catches may not represent the vector species and numbers attracted to hosts. PMID:23497628

The range of attraction for light traps catching Culicoides biting midges (Diptera: Ceratopogonidae).

PubMed

Kirkeby, Carsten; Græsbøll, Kaare; Stockmarr, Anders; Christiansen, Lasse E; Bødker, René

2013-03-15

Culicoides are vectors of e.g. bluetongue virus and Schmallenberg virus in northern Europe. Light trapping is an important tool for detecting the presence and quantifying the abundance of vectors in the field. Until now, few studies have investigated the range of attraction of light traps. Here we test a previously described mathematical model (Model I) and two novel models for the attraction of vectors to light traps (Model II and III). In Model I, Culicoides fly to the nearest trap from within a fixed range of attraction. In Model II Culicoides fly towards areas with greater light intensity, and in Model III Culicoides evaluate light sources in the field of view and fly towards the strongest. Model II and III incorporated the directionally dependent light field created around light traps with fluorescent light tubes. All three models were fitted to light trap collections obtained from two novel experimental setups in the field where traps were placed in different configurations. Results showed that overlapping ranges of attraction of neighboring traps extended the shared range of attraction. Model I did not fit data from any of the experimental setups. Model II could only fit data from one of the setups, while Model III fitted data from both experimental setups. The model with the best fit, Model III, indicates that Culicoides continuously evaluate the light source direction and intensity. The maximum range of attraction of a single 4W CDC light trap was estimated to be approximately 15.25 meters. The attraction towards light traps is different from the attraction to host animals and thus light trap catches may not represent the vector species and numbers attracted to hosts.

Enhanced Burst-Suppression and Disruption of Local Field Potential Synchrony in a Mouse Model of Focal Cortical Dysplasia Exhibiting Spike-Wave Seizures.

PubMed

Williams, Anthony J; Zhou, Chen; Sun, Qian-Quan

2016-01-01

Focal cortical dysplasias (FCDs) are a common cause of brain seizures and are often associated with intractable epilepsy. Here we evaluated aberrant brain neurophysiology in an in vivo mouse model of FCD induced by neonatal freeze lesions (FLs) to the right cortical hemisphere (near S1). Linear multi-electrode arrays were used to record extracellular potentials from cortical and subcortical brain regions near the FL in anesthetized mice (5-13 months old) followed by 24 h cortical electroencephalogram (EEG) recordings. Results indicated that FL animals exhibit a high prevalence of spontaneous spike-wave discharges (SWDs), predominately during sleep (EEG), and an increase in the incidence of hyper-excitable burst/suppression activity under general anesthesia (extracellular recordings, 0.5%-3.0% isoflurane). Brief periods of burst activity in the local field potential (LFP) typically presented as an arrhythmic pattern of increased theta-alpha spectral peaks (4-12 Hz) on a background of low-amplitude delta activity (1-4 Hz), were associated with an increase in spontaneous spiking of cortical neurons, and were highly synchronized in control animals across recording sites in both cortical and subcortical layers (average cross-correlation values ranging from +0.73 to +1.0) with minimal phase shift between electrodes. However, in FL animals, cortical vs. subcortical burst activity was strongly out of phase with significantly lower cross-correlation values compared to controls (average values of -0.1 to +0.5, P < 0.05 between groups). In particular, a marked reduction in the level of synchronous burst activity was observed, the closer the recording electrodes were to the malformation (Pearson's Correlation = 0.525, P < 0.05). In a subset of FL animals (3/9), burst activity also included a spike or spike-wave pattern similar to the SWDs observed in unanesthetized animals. In summary, neonatal FLs increased the hyperexcitable pattern of burst activity induced by anesthesia and disrupted field potential synchrony between cortical and subcortical brain regions near the site of the cortical malformation. Monitoring the altered electrophysiology of burst activity under general anesthesia with multi-dimensional micro-electrode arrays may serve to define distinct neurophysiological biomarkers of epileptogenesis in human brain and improve techniques for surgical resection of epileptogenic malformed brain tissue.

Hormonal responses during a prolonged military field exercise with variable exercise intensity.

PubMed

Kyröläinen, Heikki; Karinkanta, Jari; Santtila, Matti; Koski, Harri; Mäntysaari, Matti; Pullinen, Teemu

2008-03-01

The purpose of the present study was to test the hypothesis that the magnitude of hormonal concentration alterations during a prolonged military field exercise with constant energy intake (EI) is influenced by changes in energy deficit (ED) induced by varying the exercise intensity. Basal serum hormone concentrations were measured in a group of healthy young male volunteers (n = 7) during a 20-day field exercise. During the first week of the exercise, the average ED was 4,000 kcal/day (P-I), in the second week only 450 kcal/day (P-II), and in the last week 1,000 kcal/day (P-III). During the first 5 days of the field exercise, significant increases in cortisol (COR, +32%) and growth hormone (GH, +616%) concentrations were observed, while insulin (INS, -70%), total testosterone (TES, -27%), free testosterone (TES(free), -26%) decreased. However, after these initial responses, COR and GH returned to the pre-exercise level by the beginning of P-II. Also TES and TES(free) recovered to the pre-exercise level by the beginning of P-III, and INS by the end of P-III. The concentration of TES (+29%) increased above the pre-exercise level by the beginning of P-III. Serum thyroxin (T(4)) concentration was significantly lesser (-12%) and urine urea concentration significantly higher (+78%) after the field exercise than before it. Therefore, it can be concluded that the lower levels of ED in the second and third phase (ED <1,000 kcal/day) allowed recovery of hormonal changes observed in the first phase with ED much greater than 1,000 kcal/day.

DSM-III field trials: I. Initial interrater diagnostic reliability.

PubMed

Spitzer, R L; Forman, J B; Nee, J

1979-06-01

The interrater agreement for major diagnostic categories in studies using DSM-I and DSM-II was usually only fair or poor. In phase one of the DSM-III field trials the overall kappa coefficient of agreement for axis I diagnoses of 281 adult patients was .78 for joint interviews and .66 for diagnoses made after separate interviews; for axis II--personality disorders and specific developmental disorders--the coefficients of agreement were .61 and .54. The interrater reliability of DSM--III is, in general, higher than that previously achieved and may be due to changes in the classification itself, the separation of axis I from axis II conditions, the systematic description of the various disorders, and the inclusion of diagnostic criteria.

Comprehensive review of neurophysiologic basis and diagnostic interventions in managing chronic spinal pain.

PubMed

Manchikanti, Laxmaiah; Boswell, Mark V; Singh, Vijay; Derby, Richard; Fellows, Bert; Falco, Frank J E; Datta, Sukdeb; Smith, Howard S; Hirsch, Joshua A

2009-01-01

Understanding the neurophysiological basis of chronic spinal pain and diagnostic interventional techniques is crucial in the proper diagnosis and management of chronic spinal pain. Central to the understanding of the structural basis of chronic spinal pain is the provision of physical diagnosis and validation of patient symptomatology. It has been shown that history, physical examination, imaging, and nerve conduction studies in non-radicular or discogenic pain are unable to diagnose the precise cause in 85% of the patients. In contrast, controlled diagnostic blocks have been shown to determine the cause of pain in as many as 85% of the patients. To provide evidence-based clinical practice guidelines for diagnostic interventional techniques. Best evidence synthesis. Strength of evidence was assessed by the U.S. Preventive Services Task Force (USPSTF) criteria utilizing 5 levels of evidence ranging from Level I to III with 3 subcategories in Level II. Diagnostic criteria established by systematic reviews were utilized with controlled diagnostic blocks. Diagnostic criteria included at least 80% pain relief with controlled local anesthetic blocks with the ability to perform multiple maneuvers which were painful prior to the diagnostic blocks for facet joint and sacroiliac joint blocks, whereas for provocation discography, the criteria included concordant pain upon stimulation of the target disc with 2 adjacent discs producing no pain at all. The indicated level of evidence for diagnostic lumbar, cervical, and thoracic facet joint nerve blocks is Level I or II-1. The indicated evidence is Level II-2 for lumbar and cervical discography, whereas it is Level II-3 for thoracic provocation discography. The evidence for diagnostic sacroiliac joint nerve blocks is Level II-2. Level of evidence for selective nerve root blocks for diagnostic purposes is Level II-3. Limitations of this guideline preparation include a continued paucity of literature and conflicts in preparation of systematic reviews and guidelines. These guidelines include the evaluation of evidence for diagnostic interventional procedures in managing chronic spinal pain and recommendations. However, these guidelines do not constitute inflexible treatment recommendations. These guidelines also do not represent a "standard of care."

Tuning of Magnetic Anisotropy in Hexairon(III) Rings by Host-Guest Interactions: An Investigation by High-Field Torque Magnetometry.

PubMed

Cornia; Affronte; Jansen; Abbati; Gatteschi

1999-08-01

Full chemical control of magnetic anisotropy in hexairon(III) rings can be achieved by varying the size of the guest alkali metal ion. Dramatically different anisotropies characterize the Li(I) and Na(I) complexes of [Fe(6)(OMe)(12)(L)(6)] (L=1,3-propanedione derivatives; a schematic representation of the Li(I) complex is shown), as revealed by high-field torque magnetometry-Iron: (g), oxygen: o, carbon: o, Li(+): plus sign in circle.

[Neurosciences and the ravings of the Soviet era. Spanish Republican physicians, a set of privileged witnesses].

PubMed

Marco-Igual, Miguel

2011-08-16

This study analyses the links between the Russian and Soviet neurosciences and their Spanish counterpart, especially with regard to the experiences of the Spanish Republican physicians exiled in the USSR. The Russian neurosciences, which date back to the second half of the 19th century, followed a path that ran parallel to the discipline throughout the rest of Europe and finally displayed signs of being influenced by the German and French schools. Important figures include Alexei Kojevnikov and Vladimir Bekhterev in neurology, Sergei Korsakov in psychiatry, Ivan Pavlov and his disciple Piotr Anojin in neurophysiology, Lev Vygotsky and Alexander Luria in neuropsychology, and Nikolai Burdenko in neurosurgery. When the Bolsheviks came to power, they brought with them a progressive conception of health care, which was modified during the Stalinist era to serve political interests, above all in the case of psychiatry. During the first third of the 20th century, Spanish scientists became interested in Pavlov's reflexology and the Soviets took a similar interest in Spanish histology. Among the 4500 Spanish Republicans who emigrated to the USSR because of the Spanish Civil War, there were several dozen physicians who were privileged witnesses of the madness that shook the science and the health care of that period. Relevant names worth citing here from the field of the neurosciences include Juan Planelles and Ramon Alvarez-Buylla in neurophysiology, Federico Pascual and Florencio Villa Landa in psychiatry, Angel Escobio and Maria Perez in neurology, Julian Fuster in neurosurgery and Manuel Arce in neuroimaging. © 2011 Revista de Neurología

Image quality of the cat eye measured during retinal ganglion cell experiments

PubMed Central

Bonds, A. B.; Enroth-Cugell, Christina; Pinto, L. H.

1972-01-01

1. The modulation transfer function (MTF) of the dioptrics of fifteen cat eyes was determined. The aerial image, formed by the eye of a standard object (a 0·5-1·0° annulus), was photographed. The transmission of the film negative was measured with a scanning microdensitometer to yield the light distribution within the aerial image. Correcting for the double passage, this experimentally determined light distribution and the known object light distribution were used to obtain the MTF, applying Fourier methods. Each MTF was used to calculate the light distribution within the retinal image of stimuli of various geometry used in experiments on retinal ganglion cells in the same eye. 2. When the eye was equipped with an artificial pupil of the same size as that used in the neurophysiological experiments (4·0-4·8 mm diam.) the MTF had fallen to 0·5 at 2·43 c/deg. When the pupil was removed the MTF had fallen to 0·5 at a much lower spatial frequency (1·0 c/deg). This shows that even when one uses an artificial pupil too large to provide optimal image quality there is a vast improvement over using no pupil. 3. These image quality measurements were prompted by the need to know the actual stimulus image in experiments on the functional organization of the receptive field, a need exemplified in this paper by a few specific physiological results. The full neurophysiological results appear in the next two papers. ImagesFig. 3Fig. 4 PMID:5014105

Effect of pain neurophysiology education on physiotherapy students' understanding of chronic pain, clinical recommendations and attitudes towards people with chronic pain: a randomised controlled trial.

PubMed

Colleary, G; O'Sullivan, K; Griffin, D; Ryan, C G; Martin, D J

2017-12-01

To investigate the effect of pain neurophysiology education (PNE) on student physiotherapists': (1) knowledge of chronic pain; (2) attitudes towards patients with chronic pain; and (3) clinical recommendations for patients with chronic pain. Multicentre single-blind randomised controlled trial. One UK and one Irish university. Seventy-two student physiotherapists. Participants received either PNE (intervention) or a control education. Both were delivered in a 70-minute group lecture. (1) The Revised Pain Neurophysiology Quiz to assess knowledge; (2) the Health Care Pain Attitudes and Impairment Relationship Scale (HC-PAIRS) to assess attitudes; and (3) a case vignette to assess the appropriateness of clinical recommendations. Post education, the PNE group had a greater increase in pain neurophysiology knowledge [mean difference 4.0 (95% confidence interval 3.2 to 4.7), P<0.01] and more improved attitudes [-17.5 (95% confidence interval -22.1 to -12.9), P<0.01] compared with the control group. Post education, students in the PNE group were more likely to make appropriate recommendations regarding work (94% vs 56%), exercise (92% vs 56%), activity (94% vs 67%) and bed rest (69% vs 33%) compared with those in the control group (P<0.05). The improvements in knowledge, attitudes and recommendations for pain management show that PNE is a potentially valuable part of the education of physiotherapy students, and could be used on a more widespread basis. There is a need to investigate whether these findings can be replicated in other healthcare professions, and how well these reported changes lead to changes in actual clinical behaviour and the clinical outcomes of patients. Copyright © 2017 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

Differential neurophysiological effects of magnetic seizure therapy (MST) and electroconvulsive shock (ECS) in non-human primates.

PubMed

Cycowicz, Yael M; Luber, Bruce; Spellman, Timothy; Lisanby, Sarah H

2008-07-01

Magnetic seizure therapy (MST) is under development as a means of reducing the side effects of electroconvulsive therapy (ECT) through enhanced control over patterns of seizure induction and spread. We previously reported that chronic treatment with MST resulted in less impairment in cognitive function than electroconvulsive shock (ECS) in a non-human primate model of convulsive therapy. Here we present quantitative analyses of ictal expression and post-ictal suppression following ECS, MST, and anesthesia-alone sham in the same model to test whether differential neurophysiological characteristics of the seizures could be identified. Rhesus monkeys received 4 weeks of daily treatment with ECS, MST, and anesthesia-alone sham in a counterbalanced order separated by a recovery period. Both ECS and MST were given bilaterally at 2.5 x seizure threshold. Neurophysiological characteristics were derived from two scalp EEG electrode recording sites during and immediately following the ictal period, and were compared to sham treatment. EEG power within four frequencies (delta, theta, alpha and beta) was calculated. Our results support earlier findings from intracerebral electrode recordings demonstrating that MST- and ECS- induced seizures elicit differential patterns of EEG activation. Specifically, we found that ECS shows significantly more marked ictal expression, and more intense post-ictal suppression than MST in the theta, alpha, and beta frequency bands (Ps < .05). However, the ECS and MST were indistinguishable in the delta frequency band during both ictal and post-ictal periods. These results demonstrate that magnetic seizure induction can result in seizures that differ in some neurophysiological respects compared with ECS, but that these modalities share some aspects of seizure expression. The clinical significance of these similarities and differences awaits clinical correlation.

Audio-Visual Integration in a Redundant Target Paradigm: A Comparison between Rhesus Macaque and Man

PubMed Central

Bremen, Peter; Massoudi, Rooholla; Van Wanrooij, Marc M.; Van Opstal, A. J.

2017-01-01

The mechanisms underlying multi-sensory interactions are still poorly understood despite considerable progress made since the first neurophysiological recordings of multi-sensory neurons. While the majority of single-cell neurophysiology has been performed in anesthetized or passive-awake laboratory animals, the vast majority of behavioral data stems from studies with human subjects. Interpretation of neurophysiological data implicitly assumes that laboratory animals exhibit perceptual phenomena comparable or identical to those observed in human subjects. To explicitly test this underlying assumption, we here characterized how two rhesus macaques and four humans detect changes in intensity of auditory, visual, and audio-visual stimuli. These intensity changes consisted of a gradual envelope modulation for the sound, and a luminance step for the LED. Subjects had to detect any perceived intensity change as fast as possible. By comparing the monkeys' results with those obtained from the human subjects we found that (1) unimodal reaction times differed across modality, acoustic modulation frequency, and species, (2) the largest facilitation of reaction times with the audio-visual stimuli was observed when stimulus onset asynchronies were such that the unimodal reactions would occur at the same time (response, rather than physical synchrony), and (3) the largest audio-visual reaction-time facilitation was observed when unimodal auditory stimuli were difficult to detect, i.e., at slow unimodal reaction times. We conclude that despite marked unimodal heterogeneity, similar multisensory rules applied to both species. Single-cell neurophysiology in the rhesus macaque may therefore yield valuable insights into the mechanisms governing audio-visual integration that may be informative of the processes taking place in the human brain. PMID:29238295

Audio-Visual Integration in a Redundant Target Paradigm: A Comparison between Rhesus Macaque and Man.

PubMed

Bremen, Peter; Massoudi, Rooholla; Van Wanrooij, Marc M; Van Opstal, A J

2017-01-01

The mechanisms underlying multi-sensory interactions are still poorly understood despite considerable progress made since the first neurophysiological recordings of multi-sensory neurons. While the majority of single-cell neurophysiology has been performed in anesthetized or passive-awake laboratory animals, the vast majority of behavioral data stems from studies with human subjects. Interpretation of neurophysiological data implicitly assumes that laboratory animals exhibit perceptual phenomena comparable or identical to those observed in human subjects. To explicitly test this underlying assumption, we here characterized how two rhesus macaques and four humans detect changes in intensity of auditory, visual, and audio-visual stimuli. These intensity changes consisted of a gradual envelope modulation for the sound, and a luminance step for the LED. Subjects had to detect any perceived intensity change as fast as possible. By comparing the monkeys' results with those obtained from the human subjects we found that (1) unimodal reaction times differed across modality, acoustic modulation frequency, and species, (2) the largest facilitation of reaction times with the audio-visual stimuli was observed when stimulus onset asynchronies were such that the unimodal reactions would occur at the same time (response, rather than physical synchrony), and (3) the largest audio-visual reaction-time facilitation was observed when unimodal auditory stimuli were difficult to detect, i.e., at slow unimodal reaction times. We conclude that despite marked unimodal heterogeneity, similar multisensory rules applied to both species. Single-cell neurophysiology in the rhesus macaque may therefore yield valuable insights into the mechanisms governing audio-visual integration that may be informative of the processes taking place in the human brain.

Visual but not motor processes predict simple visuomotor reaction time of badminton players.

PubMed

Hülsdünker, Thorben; Strüder, Heiko K; Mierau, Andreas

2018-03-01

The athlete's brain exhibits significant functional adaptations that facilitate visuomotor reaction performance. However, it is currently unclear if the same neurophysiological processes that differentiate athletes from non-athletes also determine performance within a homogeneous group of athletes. This information can provide valuable help for athletes and coaches aiming to optimize existing training regimes. Therefore, this study aimed to identify the neurophysiological correlates of visuomotor reaction performance in a group of skilled athletes. In 36 skilled badminton athletes, electroencephalography (EEG) was used to investigate pattern reversal and motion onset visual-evoked potentials (VEPs) as well as visuomotor reaction time (VMRT) during a simple reaction task. Stimulus-locked and response-locked event-related potentials (ERPs) in visual and motor regions as well as the onset of muscle activation (EMG onset) were determined. Correlation and multiple regression analyses identified the neurophysiological parameters predicting EMG onset and VMRT. For pattern reversal stimuli, the P100 latency and age best predicted EMG onset (r = 0.43; p = .003) and VMRT (r = 0.62; p = .001). In the motion onset experiment, EMG onset (r = 0.80; p < .001) and VMRT (r = 0.78; p < .001) were predicted by N2 latency and age. In both conditions, cortical potentials in motor regions were not correlated with EMG onset or VMRT. It is concluded that previously identified neurophysiological parameters differentiating athletes from non-athletes do not necessarily determine performance within a homogeneous group of athletes. Specifically, the speed of visual perception/processing predicts EMG onset and VMRT in skilled badminton players while motor-related processes, although differentiating athletes from non-athletes, are not associated simple with visuomotor reaction performance.

Intrinsic neurophysiological properties of hilar ectopic and normotopic dentate granule cells in human temporal lobe epilepsy and a rat model.

PubMed

Althaus, A L; Sagher, O; Parent, J M; Murphy, G G

2015-02-15

Hilar ectopic dentate granule cells (DGCs) are a salient feature of aberrant plasticity in human temporal lobe epilepsy (TLE) and most rodent models of the disease. Recent evidence from rodent TLE models suggests that hilar ectopic DGCs contribute to hyperexcitability within the epileptic hippocampal network. Here we investigate the intrinsic excitability of DGCs from humans with TLE and the rat pilocarpine TLE model with the objective of comparing the neurophysiology of hilar ectopic DGCs to their normotopic counterparts in the granule cell layer (GCL). We recorded from 36 GCL and 7 hilar DGCs from human TLE tissue. Compared with GCL DGCs, hilar DGCs in patient tissue exhibited lower action potential (AP) firing rates, more depolarized AP threshold, and differed in single AP waveform, consistent with an overall decrease in excitability. To evaluate the intrinsic neurophysiology of hilar ectopic DGCs, we made recordings from retrovirus-birthdated, adult-born DGCs 2-4 mo after pilocarpine-induced status epilepticus or sham treatment in rats. Hilar DGCs from epileptic rats exhibited higher AP firing rates than normotopic DGCs from epileptic or control animals. They also displayed more depolarized resting membrane potential and wider AP waveforms, indicating an overall increase in excitability. The contrasting findings between disease and disease model may reflect differences between the late-stage disease tissue available from human surgical specimens and the earlier disease stage examined in the rat TLE model. These data represent the first neurophysiological characterization of ectopic DGCs from human hippocampus and prospectively birthdated ectopic DGCs in a rodent TLE model. Copyright © 2015 the American Physiological Society.

Risk Factors for Post-treatment Complex Regional Pain Syndrome (CRPS): An Analysis of 647 Cases of CRPS from the Danish Patient Compensation Association.

PubMed

Petersen, Pelle B; Mikkelsen, Kim L; Lauritzen, Jes B; Krogsgaard, Michael R

2018-03-01

Complex regional pain syndrome is a challenging condition that includes a broad spectrum of sensory, autonomic, and motor features predominantly in extremities recovering from a trauma. Few large-scale studies have addressed occurrence of and factors associated with complex regional pain syndrome (CRPS) following orthopedic treatment. The present study aimed to identify factors associated with post-treatment development of CRPS. Using the Danish Patient Compensation Association's database, we identified 647 patients claiming post-treatment CRPS between 1992 and 2015. Age, gender, initial diagnosis, treatment, and amount of compensation were extracted. Multivariate logistic regressions were performed to identify variables associated with approval of the claim. For carpal tunnel syndrome (CTS) patients, we registered whether symptoms were bilateral or unilateral and if neurophysiology prior to treatment was pathologic. The following ratios were found: women:men was 4:1, primary diagnosis to the upper limb:lower limb was 2.5:1, and surgical:nonsurgical treatment was 3:1. Mean age was 47.5 ± 13.7 years, and no intergender difference was detected. Antebrachial fracture (23%) and CTS (9%) were the most common primary conditions. Surgical treatment was associated with approval of the claim (odds ratio 3.5, 95% confidence interval 2.3 to 5.3; P < 0.001). Half of CTS patients had normal neurophysiology prior to surgery; among patients with unilateral symptoms, 71.4% had normal neurophysiology. Female gender, surgical treatment, and treatment to the upper limb were risk factors. Elective surgery accounted for a large number of post-treatment CRPS patients. In CTS patients developing CRPS, normal neurophysiological examination findings were common, and it could be suspected that these patients were suffering from an pre-clinical stage of CRPS, not CTS. © 2017 World Institute of Pain.

Neuroanatomy, neurophysiology, and dysfunction of the female lower urinary tract: a review.

PubMed

Unger, Cécile A; Tunitsky-Bitton, Elena; Muffly, Tyler; Barber, Matthew D

2014-01-01

The 2 major functions of the lower urinary tract are the storage and emptying of urine. These processes are controlled by complex neurophysiologic mechanisms and are subject to injury and disease. When there is disruption of the neurologic control centers, dysfunction of the lower urinary tract may occur. This is sometimes referred to as the "neurogenic bladder." The manifestation of dysfunction depends on the level of injury and severity of disruption. Patients with lesions above the spinal cord often have detrusor overactivity with no disruption in detrusor-sphincter coordination. Patients with well-defined suprasacral spinal cord injuries usually present with intact reflex detrusor activity but have detrusor sphincter dyssynergia, whereas injuries to or below the sacral spinal cord usually lead to persistent detrusor areflexia. A complete gynecologic, urologic, and neurologic examination should be performed when evaluating patients with neurologic lower urinary tract dysfunction. In addition, urodynamic studies and neurophysiologic testing can be used in certain circumstances to help establish diagnosis or to achieve better understanding of a patient's vesicourethral functioning. In the management of neurogenic lower urinary tract dysfunction, the primary goal is improvement of a patient's quality of life. Second to this is the prevention of chronic damage to the bladder and kidneys, which can lead to worsening impairment and symptoms. Treatment is often multifactorial, including behavioral modifications, bladder training programs, and pharmacotherapy. Surgical procedures are often a last resort option for management. An understanding of the basic neurophysiologic mechanisms of the lower urinary tract can guide providers in their evaluation and treatment of patients who present with lower urinary tract disorders. As neurologic diseases progress, voiding function often changes or worsens, necessitating a good understanding of the underlying physiology in question.

The neurophysiology of language processing shapes the evolution of grammar: evidence from case marking.

PubMed

Bickel, Balthasar; Witzlack-Makarevich, Alena; Choudhary, Kamal K; Schlesewsky, Matthias; Bornkessel-Schlesewsky, Ina

2015-01-01

Do principles of language processing in the brain affect the way grammar evolves over time or is language change just a matter of socio-historical contingency? While the balance of evidence has been ambiguous and controversial, we identify here a neurophysiological constraint on the processing of language that has a systematic effect on the evolution of how noun phrases are marked by case (i.e. by such contrasts as between the English base form she and the object form her). In neurophysiological experiments across diverse languages we found that during processing, participants initially interpret the first base-form noun phrase they hear (e.g. she…) as an agent (which would fit a continuation like … greeted him), even when the sentence later requires the interpretation of a patient role (as in … was greeted). We show that this processing principle is also operative in Hindi, a language where initial base-form noun phrases most commonly denote patients because many agents receive a special case marker ("ergative") and are often left out in discourse. This finding suggests that the principle is species-wide and independent of the structural affordances of specific languages. As such, the principle favors the development and maintenance of case-marking systems that equate base-form cases with agents rather than with patients. We confirm this evolutionary bias by statistical analyses of phylogenetic signals in over 600 languages worldwide, controlling for confounding effects from language contact. Our findings suggest that at least one core property of grammar systematically adapts in its evolution to the neurophysiological conditions of the brain, independently of socio-historical factors. This opens up new avenues for understanding how specific properties of grammar have developed in tight interaction with the biological evolution of our species.

New paradigm for understanding in-flight decision making errors: a neurophysiological model leveraging human factors.

PubMed

Souvestre, P A; Landrock, C K; Blaber, A P

2008-08-01

Human factors centered aviation accident analyses report that skill based errors are known to be cause of 80% of all accidents, decision making related errors 30% and perceptual errors 6%1. In-flight decision making error is a long time recognized major avenue leading to incidents and accidents. Through the past three decades, tremendous and costly efforts have been developed to attempt to clarify causation, roles and responsibility as well as to elaborate various preventative and curative countermeasures blending state of the art biomedical, technological advances and psychophysiological training strategies. In-flight related statistics have not been shown significantly changed and a significant number of issues remain not yet resolved. Fine Postural System and its corollary, Postural Deficiency Syndrome (PDS), both defined in the 1980's, are respectively neurophysiological and medical diagnostic models that reflect central neural sensory-motor and cognitive controls regulatory status. They are successfully used in complex neurotraumatology and related rehabilitation for over two decades. Analysis of clinical data taken over a ten-year period from acute and chronic post-traumatic PDS patients shows a strong correlation between symptoms commonly exhibited before, along side, or even after error, and sensory-motor or PDS related symptoms. Examples are given on how PDS related central sensory-motor control dysfunction can be correctly identified and monitored via a neurophysiological ocular-vestibular-postural monitoring system. The data presented provides strong evidence that a specific biomedical assessment methodology can lead to a better understanding of in-flight adaptive neurophysiological, cognitive and perceptual dysfunctional status that could induce in flight-errors. How relevant human factors can be identified and leveraged to maintain optimal performance will be addressed.

Time-linked concurrence of sleep bruxism, periodic limb movements, and EEG arousals in sleep bruxers and healthy controls.

PubMed

van der Zaag, Jacques; Naeije, Machiel; Wicks, Darrel J; Hamburger, Hans L; Lobbezoo, Frank

2014-01-01

Sleep bruxism (SB) and periodic limb movements during sleep (PLMS) may have a common underlying neurophysiologic mechanism, especially in relation to the occurrence of sleep-related electroencephalographic (EEG) arousals. To test this hypothesis, three research questions were assessed. First, it was assessed whether PLMS events occur more frequently in SB patients than in individuals without SB. Second, the question was put forward whether the combined presence of SB and PLMS events is more common than that of isolated SB or PLMS events in a group of SB patients. Third, as to further unravel the possible role of EEG arousals in the underlying neurophysiologic mechanism of SB and PLMS, it was assessed in a group of SB patients whether combined SB/PLMS events with associated EEG arousals are more common than those without associated EEG arousals. Positive answers to these questions could suggest a common neurophysiological basis for both movement disorders. Seventeen SB patients and 11 healthy controls were polysomnographically studied. SB, PLMS, and EEG arousals were scored. An association was noted when the occurrence was within a 3-s association zone. The PLMS index was higher in SB patients than in healthy controls (P < 0.001). Within the group of SB patients, the combined SB/PLMS index was higher than the isolated SB index (P < 0.001) and the isolated PLMS index (P = 0.018). Similarly, the combined SB/PLMS index with EEG arousal was higher than the combined SB/PLMS index without EEG arousal in SB patients (P < 0.001). The results of this study indicate that SB, PLMS, and EEG arousals commonly concur during sleep in a time-linked manner. SB and PLMS probably have a common underlying neurophysiological mechanism.

Seasonal distribution and demographical characteristics of carpal tunnel syndrome in 1039 patients.

PubMed

Gomes, Irênio; Becker, Jefferson; Ehlers, João Arthur; Kapczinski, Flávio; Nora, Daniel Bocchese

2004-09-01

To describe the demographic characteristics of gender, age, and presence of repetitive movements, intake of alcohol and non-steroid anti-inflammatories (NSAI), medical specialties that referred patients to nerve conduction studies and electromyography (NCS-EMG), school attainment, and seasonal distribution in patients with a neurophysiological diagnosis of carpal tunnel syndrome (CTS) in the State of Rio Grande do Sul, Brazil. A series of 1039 patients (1549 hands) with neurophysiologically defined CTS was studied. Patients were referred for NCS-EMG in 3 universities and 2 private services, from August 2001 to January 2003. All patients completed a questionnaire containing demographic information. The diagnosis of CTS was established following a pre-established protocol, with defined diagnostic criteria. Around one fourth of patients had already performed NCS-EMG; the greatest frequency of CTS was observed in women (5.6:1) and in patients above the age of 40. Most patients reported performing repetitive movements in their daily routine (69.7%); 12.9% reported use of NSAI and 14.9% regular intake of alcoholic beverages. A greater frequency of CTS was observed in the months of July and August, when compared to the other months of the year. Around 2/3 of the study population had completed at least secondary school. Most requests of nerve conduction studies did not provide a diagnostic hypothesis (59.9%) and neurophysiologic studies were requested mostly by traumatology/orthopedics (71.1%). We have concluded that, in our environment, CTS shows some demographical characteristics that are similar to what the literature describes. Also, we have found that most of our sample concluded at least secondary school, and was referred to neurophysiologic studies by orthopedists. To be pointed out is the seasonal distribution of CTS, which demonstrates a significant association with winter months.

Theory and practice of chaplain's spiritual care process: A psychiatrist's experiences of chaplaincy and conceptualizing trans-personal model of mindfulness

PubMed Central

Parameshwaran, Ramakrishnan

2015-01-01

Background: Of various spiritual care methods, mindfulness meditation has found consistent application in clinical intervention and research. “Listening presence,” a chaplain's model of mindfulness and its trans-personal application in spiritual care is least understood and studied. Aim: The aim was to develop a conceptualized understanding of chaplain's spiritual care process based on neuro-physiological principles of mindfulness and interpersonal empathy. Materials and Methods: Current understandings on neuro-physiological mechanisms of mindfulness-based interventions (MBI) and interpersonal empathy such as theory of mind and mirror neuron system are used to build a theoretical framework for chaplain's spiritual care process. Practical application of this theoretical model is illustrated using a carefully recorded clinical interaction, in verbatim, between chaplain and his patient. Qualitative findings from this verbatim are systematically analyzed using neuro-physiological principles. Results and Discussion: Chaplain's deep listening skills to experience patient's pain and suffering, awareness of his emotions/memories triggered by patient's story and ability to set aside personal emotions, and judgmental thoughts formed intra-personal mindfulness. Chaplain's insights on and ability to remain mindfully aware of possible emotions/thoughts in the patient, and facilitating patient to return and re-return to become aware of internal emotions/thoughts helps the patient develop own intra-personal mindfulness leading to self-healing. This form of care involving chaplain's mindfulness of emotions/thoughts of another individual, that is, patient, may be conceptualized as trans-personal model of MBI. Conclusion: Chaplain's approach may be a legitimate form of psychological therapy that includes inter and intra-personal mindfulness. Neuro-physiological mechanisms of empathy that underlie Chaplain's spiritual care process may establish it as an evidence-based clinical method of care. PMID:25657453

Cognitive requirements of competing neuro-behavioral decision systems: some implications of temporal horizon for managerial behavior in organizations

PubMed Central

Foxall, Gordon R.

2014-01-01

Interpretation of managerial activity in terms of neuroscience is typically concerned with extreme behaviors such as corporate fraud or reckless investment (Peterson, 2007; Wargo et al., 2010a). This paper is concerned to map out the neurophysiological and cognitive mechanisms at work across the spectrum of managerial behaviors encountered in more day-to-day contexts. It proposes that the competing neuro-behavioral decisions systems (CNBDS) hypothesis (Bickel et al., 2012b) captures well the range of managerial behaviors that can be characterized as hyper- or hypo-activity in either the limbically-based impulsive system or the frontal-cortically based executive system with the corresponding level of activity encountered in the alternative brain region. This pattern of neurophysiological responding also features in the Somatic Marker Hypothesis (Damasio, 1994) and in Reinforcement Sensitivity Theory (RST; Gray and McNaughton, 2000; McNaughton and Corr, 2004), which usefully extend the thesis, for example in the direction of personality. In discussing these theories, the paper has three purposes: to clarify the role of cognitive explanation in neuro-behavioral decision theory, to propose picoeconomics (Ainslie, 1992) as the cognitive component of competing neuro-behavioral decision systems theory and to suggest solutions to the problems of imbalanced neurophysiological activity in managerial behavior. The first is accomplished through discussion of the role of picoeconomics in neuro-behavioral decision theory; the second, by consideration of adaptive-innovative cognitive styles (Kirton, 2003) in the construction of managerial teams, a theme that can now be investigated by a dedicated research program that incorporates psychometric analysis of personality types and cognitive styles involved in managerial decision-making and the underlying neurophysiological bases of such decision-making. PMID:24744719

Addressing Neuroplastic Changes in Distributed Areas of the Nervous System Associated With Chronic Musculoskeletal Disorders.

PubMed

Pelletier, René; Higgins, Johanne; Bourbonnais, Daniel

2015-11-01

Present interventions utilized in musculoskeletal rehabilitation are guided, in large part, by a biomedical model where peripheral structural injury is believed to be the sole driver of the disorder. There are, however, neurophysiological changes across different areas of the peripheral and central nervous systems, including peripheral receptors, dorsal horn of the spinal cord, brain stem, sensorimotor cortical areas, and the mesolimbic and prefrontal areas associated with chronic musculoskeletal disorders, including chronic low back pain, osteoarthritis, and tendon injuries. These neurophysiological changes appear not only to be a consequence of peripheral structural injury but also to play a part in the pathophysiology of chronic musculoskeletal disorders. Neurophysiological changes are consistent with a biopsychosocial formulation reflecting the underlying mechanisms associated with sensory and motor findings, psychological traits, and perceptual changes associated with chronic musculoskeletal conditions. These changes, therefore, have important implications in the clinical manifestation, pathophysiology, and treatment of chronic musculoskeletal disorders. Musculoskeletal rehabilitation professionals have at their disposal tools to address these neuroplastic changes, including top-down cognitive-based interventions (eg, education, cognitive-behavioral therapy, mindfulness meditation, motor imagery) and bottom-up physical interventions (eg, motor learning, peripheral sensory stimulation, manual therapy) that induce neuroplastic changes across distributed areas of the nervous system and affect outcomes in patients with chronic musculoskeletal disorders. Furthermore, novel approaches such as the use of transcranial direct current stimulation and repetitive transcranial magnetic stimulation may be utilized to help renormalize neurological function. Comprehensive treatment addressing peripheral structural injury as well as neurophysiological changes occurring across distributed areas of the nervous system may help to improve outcomes in patients with chronic musculoskeletal disorders. © 2015 American Physical Therapy Association.

Congenital myasthenic syndrome with episodic apnoea: clinical, neurophysiological and genetic features in the long-term follow-up of 19 patients.

PubMed

McMacken, Grace; Whittaker, Roger G; Evangelista, Teresinha; Abicht, Angela; Dusl, Marina; Lochmüller, Hanns

2018-01-01

Congenital myasthenic syndrome with episodic apnoea (CMS-EA) is a rare but potentially treatable cause of apparent life-threatening events in infancy. The underlying mechanisms for sudden and recurrent episodes of respiratory arrest in these patients are unclear. Whilst CMS-EA is most commonly caused by mutations in CHAT, the list of associated genotypes is expanding. We reviewed clinical information from 19 patients with CMS-EA, including patients with mutations in CHAT, SLC5A7 and RAPSN, and patients lacking a genetic diagnosis. Lack of genetic diagnosis was more common in CMS-EA than in CMS without EA (56% n = 18, compared to 7% n = 97). Most patients manifested intermittent apnoea in the first 4 months of life (74%, n = 14). A degree of clinical improvement with medication was observed in most patients (74%, n = 14), but the majority of cases also showed a tendency towards complete remission of apnoeic events with age (mean age of resolution 2 years 5 months). Signs of impaired neuromuscular transmission were detected on neurophysiology studies in 79% (n = 15) of cases, but in six cases, this was only apparent following specific neurophysiological testing protocols (prolonged high-frequency stimulation). A relatively large proportion of CMS-EA remains genetically undiagnosed, which suggests the existence of novel causative CMS genes which remain uncharacterised. In light of the potential for recurrent life-threatening apnoeas in early life and the positive response to therapy, early diagnostic consideration of CMS-EA is critical, but without specific neurophysiology tests, it may go overlooked.

ETV REPORT - PHYSICAL REMOVAL OF CRYPTOSPORIDIUM OOCYSTS AND GIARDIA CYSTS IN DRINKING WATER, LEOPOLD MEMBRANE SYSTEMS ULTRABAR ULTRAFILTRATION SYSTEM WITH 60 INCH MARK III ELEMENT AT PITTSBURG, PA - NSF/00/10/EPADW395

EPA Science Inventory

Verification testing of the Leopold Ultrabar Mark III Ultrafiltration Systems was conducted from February 3-March9, 1999. The performance claim evaluated during field testing of the Leopold Ultrabar Mark III Ultrafiltration system was that the system is capable of a minimum 3 log...

Synthesis, properties and applications of 2D layered MIIIXVI (M = Ga, In; X = S, Se, Te) materials.

PubMed

Xu, Kai; Yin, Lei; Huang, Yun; Shifa, Tofik Ahmed; Chu, Junwei; Wang, Feng; Cheng, Ruiqing; Wang, Zhenxing; He, Jun

2016-09-29

Group III-VI compounds M III X VI (M = Ga, In; X = S, Se, Te) are one class of important 2D layered materials and are currently attracting increasing interest due to their unique electronic and optoelectronic properties and their great potential applications in various other fields. Similar to 2D layered transition metal dichalcogenides (TMDs), M III X VI also have the significant merits of ultrathin thickness, ultrahigh surface-to-volume ratio, and high compatibility with flexible devices. More impressively, in contrast with TMDCs, M III X VI demonstrate many superior properties, such as direct band gap electronic structure, high carrier mobility, rare p-type electronic behaviors, high charge density, and so on. These unique characteristics cause high-performance device applications in electronics, optoelectronics, and optics. In this review, we aim to provide a summary of the state-of-the-art of research activities in 2D layered M III X VI materials. The scope of the review covers the synthesis and properties of 2D layered M III X VI materials and their van der Waals heterostructures. We especially focus on the applications in electronics and optoelectronics. Moreover, the review concludes with some perspectives on future developments in this field.

Neurophysiology and Neuroanatomy of Reflexive and Volitional Saccades: Evidence from Studies of Humans

PubMed Central

McDowell, Jennifer E.; Dyckman, Kara A.; Austin, Benjamin; Clementz, Brett A.

2008-01-01

This review provides a summary of the contributions made by human functional neuroimaging studies to the understanding of neural correlates of saccadic control. The generation of simple visually-guided saccades (redirections of gaze to a visual stimulus or prosaccades) and more complex volitional saccades require similar basic neural circuitry with additional neural regions supporting requisite higher level processes. The saccadic system has been studied extensively in non-human primates (e.g. single unit recordings) and humans (e.g. lesions and neuroimaging). Considerable knowledge of this system’s functional neuroanatomy makes it useful for investigating models of cognitive control. The network involved in prosaccade generation (by definition exogenously-driven) includes subcortical (striatum, thalamus, superior colliculus, and cerebellar vermis) and cortical structures (primary visual, extrastriate, and parietal cortices, and frontal and supplementary eye fields). Activation in these regions is also observed during endogenously-driven voluntary saccades (e.g. antisaccades, ocular motor delayed response or memory saccades, predictive tracking tasks and anticipatory saccades, and saccade sequencing), all of which require complex cognitive processes like inhibition and working memory. These additional requirements are supported by changes in neural activity in basic saccade circuitry and by recruitment of additional neural regions (such as prefrontal and anterior cingulate cortices). Activity in visual cortex is modulated as a function of task demands and may predict the type of saccade to be generated, perhaps via top-down control mechanisms. Neuroimaging studies suggest two foci of activation within FEF - medial and lateral - which may correspond to volitional and reflexive demands, respectively. Future research on saccade control could usefully (i) delineate important anatomical subdivisions that underlie functional differences, (ii) evaluate functional connectivity of anatomical regions supporting saccade generation using methods such as ICA and structural equation modeling, (iii) investigate how context affects behavior and brain activity, and (iv) use multi-modal neuroimaging to maximize spatial and temporal resolution. PMID:18835656

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

Attentional control of associative learning--a possible role of the central cholinergic system.

PubMed

Pauli, Wolfgang M; O'Reilly, Randall C

2008-04-02

How does attention interact with learning? Kruschke [Kruschke, J.K. (2001). Toward a unified Model of Attention in Associative Learning. J. Math. Psychol. 45, 812-863.] proposed a model (EXIT) that captures Mackintosh's [Mackintosh, N.J. (1975). A theory of attention: Variations in the associability of stimuli with reinforcement. Psychological Review, 82(4), 276-298.] framework for attentional modulation of associative learning. We developed a computational model that showed analogous interactions between selective attention and associative learning, but is significantly simplified and, in contrast to EXIT, is motivated by neurophysiological findings. Competition among input representations in the internal representation layer, which increases the contrast between stimuli, is critical for simulating these interactions in human behavior. Furthermore, this competition is modulated in a way that might be consistent with the phasic activation of the central cholinergic system, which modulates activity in sensory cortices. Specifically, phasic increases in acetylcholine can cause increased excitability of both pyramidal excitatory neurons in cortical layers II/III and cortical GABAergic inhibitory interneurons targeting the same pyramidal neurons. These effects result in increased attentional contrast in our model. This model thus represents an initial attempt to link human attentional learning data with underlying neural substrates.

Attentional control of associative learning—A possible role of the central cholinergic system

PubMed Central

Pauli, Wolfgang M.; O'Reilly, Randall C.

2010-01-01

How does attention interact with learning? Kruschke [Kruschke, J.K. (2001). Toward a unified Model of Attention in Associative Learning. J. Math. Psychol. 45, 812–863.] proposed a model (EXIT) that captures Mackintosh's [Mackintosh, N.J. (1975). A theory of attention: Variations in the associability of stimuli with reinforcement. Psychological Review, 82(4), 276–298.] framework for attentional modulation of associative learning. We developed a computational model that showed analogous interactions between selective attention and associative learning, but is significantly simplified and, in contrast to EXIT, is motivated by neurophysiological findings. Competition among input representations in the internal representation layer, which increases the contrast between stimuli, is critical for simulating these interactions in human behavior. Furthermore, this competition is modulated in a way that might be consistent with the phasic activation of the central cholinergic system, which modulates activity in sensory cortices. Specifically, phasic increases in acetylcholine can cause increased excitability of both pyramidal excitatory neurons in cortical layers II/III and cortical GABAergic inhibitory interneurons targeting the same pyramidal neurons. These effects result in increased attentional contrast in our model. This model thus represents an initial attempt to link human attentional learning data with underlying neural substrates. PMID:17870060

The uncertainty processing theory of motivation.

PubMed

Anselme, Patrick

2010-04-02

Most theories describe motivation using basic terminology (drive, 'wanting', goal, pleasure, etc.) that fails to inform well about the psychological mechanisms controlling its expression. This leads to a conception of motivation as a mere psychological state 'emerging' from neurophysiological substrates. However, the involvement of motivation in a large number of behavioural parameters (triggering, intensity, duration, and directedness) and cognitive abilities (learning, memory, decision, etc.) suggest that it should be viewed as an information processing system. The uncertainty processing theory (UPT) presented here suggests that motivation is the set of cognitive processes allowing organisms to extract information from the environment by reducing uncertainty about the occurrence of psychologically significant events. This processing of information is shown to naturally result in the highlighting of specific stimuli. The UPT attempts to solve three major problems: (i) how motivations can affect behaviour and cognition so widely, (ii) how motivational specificity for objects and events can result from nonspecific neuropharmacological causal factors (such as mesolimbic dopamine), and (iii) how motivational interactions can be conceived in psychological terms, irrespective of their biological correlates. The UPT is in keeping with the conceptual tradition of the incentive salience hypothesis while trying to overcome the shortcomings inherent to this view. Copyright 2009 Elsevier B.V. All rights reserved.

Unsymmetric (μ-oxido)/(μ-pyrazolato) and Symmetric (μ-pyrazolato)2 Bridged Diosmium Frameworks: Electronic Structure and Magnetic Properties.

PubMed

Das, Ankita; Ghosh, Prabir; Priego, José Luis; Jiménez-Aparicio, Reyes; Lahiri, Goutam Kumar

2016-09-06

The present article deals with the structurally characterized unsymmetric oxido/pyrazolato-bridged [(bpy)2Os(III)(μ-oxido)(μ-pz)Os(III)(bpy)2](ClO4)3 ([1](ClO4)3) and symmetric dipyrazolato-bridged [(bpy)2Os(II)(μ-pz)2Os(II)(bpy)2](ClO4)2 ([2](ClO4)2) (pz = pyrazolato, bpy = 2,2'-bipyridine) complexes with the Os···Os separations of 3.484 and 4.172 Å, respectively. The anti-ferromagnetically coupled Os(III) centers [E(S = 1)-E(BS(1,1) S = 0) = 322.504 cm(-1)] in 1(3+) and diamagnetic (S = 0) 2(2+) exhibit well-resolved (1)H NMR resonances. [1](ClO4)3 shows temperature- and magnetic field-dependent paramagnetism at low magnetic field and diamagnetism at high magnetic field. 1(3+) and 2(2+) display successive metal-based oxidation processes involving the intermediate mixed-valent states and isovalent congeners: Os(IV)Os(IV) (1(5+))→Os(III)Os(IV) (1(4+))⇌Os(III)Os(III) (1(3+))⇌Os(III)Os(II) (1(2+)) and Os(III)Os(III) (2(4+))→Os(II)Os(III) (2(3+))⇌Os(II)Os(II) (2(2+)) as well as bpy-centered reductions. The effect of π donor O(2-) and σ/π-donating pz(-) in 1(3+) and 2(2+), respectively, leads to varying oxidation state of the metal ions in the isolated complexes: Os(III)Os(III) versus Os(II)Os(II). UV-visible-near-IR-electron paramagnetic resonance spectro-electrochemistry and density functional theory (DFT)/time-dependent DFT calculations collectively reveal overlapping of the metal- and ligand (pz, O, bpy)-based frontier orbitals in the delocalized mixed-valent states in 1(4+) and 1(2+) with comproportionation constant (Kc) value > 1 × 10(14) as well as in isovalent 1(3+), resulting in mixed metal/ligand to metal/ligand near-IR transitions in all the three states. The mixed-valent Os(II)Os(III) state in 2(3+) exhibits high Kc value of 1 × 10(22) corresponding to a strong electrochemical coupling situation. However, closeness of the bandwidth (Δν1/2, 4861 cm(-1)) of broad and weak intervalence charge transfer transition of 2(3+) at 1360 nm (ε/M(-1) cm(-1): 490) with the calculated Δν1/2 of 4121 cm(-1) based on the Hush formula as well as spin-density distributions of Os1: 0.811/0.799, Os2: 0.045/0042, and pz: 0.162/0.173 in meso and rac diastereomeric forms, respectively, attribute its localized class II state.

Assessment of long-term wastewater irrigation impacts on the soil geochemical properties and the bioaccumulation of heavy metals to the agricultural products.

PubMed

Christou, Anastasis; Eliadou, Elena; Michael, Costas; Hapeshi, Evroula; Fatta-Kassinos, Despo

2014-08-01

An extensive field survey was employed for assessing the impacts of long-term wastewater irrigation of forage crops and orange orchards in three suburban agricultural areas in Cyprus (areas I, II, and III), as compared to rainfed agriculture, on the soil geochemical properties and the bioaccumulation of heavy metals (Zn, Ni, Mn, Cu, Co) to the agricultural products. Both ryegrass fields and orange orchards in areas I and II were continuously wastewater irrigated for 10 years, whereas clover fields in area III for 0.5, 4, and 8 years. The results revealed that wastewater reuse for irrigation caused a slight increase in soil salinity and Cl(-) content in areas I and II, and a remarkable increase, having strong correlation with the period in which wastewater irrigation was practiced, in area III. Soil salinization in area III was due to the high electrical conductivity (EC) of the wastewater applied for irrigation, attributed to the influx of seawater to the sewage collection network in area III. In addition, the wastewater irrigation practice resulted in a slight decrease of the soil pH values in area III, while a subtle impact was identified regarding the CaCO3, Fe, and heavy metal content in the three areas surveyed. The heavy metal content quantified in the forage plants' above-ground parts was below the critical levels of phytotoxicity and the maximum acceptable concentration in dairy feed, whereas heavy metals quantified in orange fruit pulp were below the maximum permissible levels (MPLs). Heavy metal phytoavailability was confined due to soil properties (high pH and clay content), as evidenced by the calculated low transfer factor (TF).

Pentacoordinate and Hexacoordinate Mn(III) Complexes of Tetradentate Schiff-Base Ligands Containing Tetracyanidoplatinate(II) Bridges and Revealing Uniaxial Magnetic Anisotropy.

PubMed

Nemec, Ivan; Herchel, Radovan; Trávníček, Zdeněk

2016-12-08

Crystal structures and magnetic properties of polymeric and trinuclear heterobimetallic Mn III ···Pt II ···Mn III coordination compounds, prepared from the Ba[Pt(CN)₄] and [Mn(L4A/B)(Cl)] ( 1a / b ) precursor complexes, are reported. The polymeric complex [{Mn(L4A)}₂{μ⁴-Pt(CN)₄}] n ( 2a ), where H₂L4A = N , N '-ethylene-bis(salicylideneiminate), comprises the {Mn(L4A)} moieties covalently connected through the [Pt(CN)₄] 2- bridges, thus forming a square-grid polymeric structure with the hexacoordinate Mn III atoms. The trinuclear complex [{Mn(L4B)}₂{μ-Pt(CN)₄}] ( 2b ), where H₂L4B = N , N '-benzene-bis(4-aminodiethylene-salicylideneiminate), consists of two [{Mn(L4B)} moieties, involving pentacoordinate Mn III atoms, bridged through the tetracyanidoplatinate (II) bridges to which they are coordinated in a trans fashion. Both complexes possess uniaxial type of magnetic anisotropy, with D (the axial parameter of zero-field splitting) = -3.7(1) in 2a and -2.2(1) cm -1 in 2b . Furthermore, the parameters of magnetic anisotropy 2a and 2b were also thoroughly studied by theoretical complete active space self-consistent field (CASSCF) methods, which revealed that the former is much more sensitive to the ligand field strength of the axial ligands.

Dynamic nuclear polarization of (1)H, (13)C, and (59)Co in a tris(ethylenediamine)cobalt(III) crystalline lattice doped with Cr(III).

PubMed

Corzilius, Björn; Michaelis, Vladimir K; Penzel, Susanne A; Ravera, Enrico; Smith, Albert A; Luchinat, Claudio; Griffin, Robert G

2014-08-20

The study of inorganic crystalline materials by solid-state NMR spectroscopy is often complicated by the low sensitivity of heavy nuclei. However, these materials often contain or can be prepared with paramagnetic dopants without significantly affecting the structure of the crystalline host. Dynamic nuclear polarization (DNP) is generally capable of enhancing NMR signals by transferring the magnetization of unpaired electrons to the nuclei. Therefore, the NMR sensitivity in these paramagnetically doped crystals might be increased by DNP. In this paper we demonstrate the possibility of efficient DNP transfer in polycrystalline samples of [Co(en)3Cl3]2·NaCl·6H2O (en = ethylenediamine, C2H8N2) doped with Cr(III) in varying concentrations between 0.1 and 3 mol %. We demonstrate that (1)H, (13)C, and (59)Co can be polarized by irradiation of Cr(III) with 140 GHz microwaves at a magnetic field of 5 T. We further explain our findings on the basis of electron paramagnetic resonance spectroscopy of the Cr(III) site and analysis of its temperature-dependent zero-field splitting, as well as the dependence of the DNP enhancement factor on the external magnetic field and microwave power. This first demonstration of DNP transfer from one paramagnetic metal ion to its diamagnetic host metal ion will pave the way for future applications of DNP in paramagnetically doped materials or metalloproteins.

Dynamic Nuclear Polarization of 1H, 13C, and 59Co in a Tris(ethylenediamine)cobalt(III) Crystalline Lattice Doped with Cr(III)

PubMed Central

2015-01-01

The study of inorganic crystalline materials by solid-state NMR spectroscopy is often complicated by the low sensitivity of heavy nuclei. However, these materials often contain or can be prepared with paramagnetic dopants without significantly affecting the structure of the crystalline host. Dynamic nuclear polarization (DNP) is generally capable of enhancing NMR signals by transferring the magnetization of unpaired electrons to the nuclei. Therefore, the NMR sensitivity in these paramagnetically doped crystals might be increased by DNP. In this paper we demonstrate the possibility of efficient DNP transfer in polycrystalline samples of [Co(en)3Cl3]2·NaCl·6H2O (en = ethylenediamine, C2H8N2) doped with Cr(III) in varying concentrations between 0.1 and 3 mol %. We demonstrate that 1H, 13C, and 59Co can be polarized by irradiation of Cr(III) with 140 GHz microwaves at a magnetic field of 5 T. We further explain our findings on the basis of electron paramagnetic resonance spectroscopy of the Cr(III) site and analysis of its temperature-dependent zero-field splitting, as well as the dependence of the DNP enhancement factor on the external magnetic field and microwave power. This first demonstration of DNP transfer from one paramagnetic metal ion to its diamagnetic host metal ion will pave the way for future applications of DNP in paramagnetically doped materials or metalloproteins. PMID:25069794

Impurity ion flow and temperature measured in a detached divertor with externally applied non-axisymmetric fields on DIII-D

DOE PAGES

Briesemeister, A. R.; Isler, R. C.; Allen, S. L.; ...

2014-11-15

In this study, externally applied non-axisymmetric magnetic fields are shown to have little effect on the impurity ion flow velocity and temperature as measured by the multichord divertor spectrometer in the DIII-D divertor for both attached and detached conditions. These experiments were performed in H-mode plasmas with the grad-B drift toward the target plates, with and without n = 3 resonant magnetic perturbations (RMPs). The flow velocity in the divertor is shown to change by as much as 30% when deuterium gas puffing is used to create detachment of the divertor plasma. No measurable changes in the C III flowmore » were observed in response to the RMP fields for the conditions used in this work. Images of the C III emission are used along with divertor Thomson scattering to show that the local electron and C III temperatures are equilibrated for the conditions shown.« less

Acting without seeing: eye movements reveal visual processing without awareness.

PubMed

Spering, Miriam; Carrasco, Marisa

2015-04-01

Visual perception and eye movements are considered to be tightly linked. Diverse fields, ranging from developmental psychology to computer science, utilize eye tracking to measure visual perception. However, this prevailing view has been challenged by recent behavioral studies. Here, we review converging evidence revealing dissociations between the contents of perceptual awareness and different types of eye movement. Such dissociations reveal situations in which eye movements are sensitive to particular visual features that fail to modulate perceptual reports. We also discuss neurophysiological, neuroimaging, and clinical studies supporting the role of subcortical pathways for visual processing without awareness. Our review links awareness to perceptual-eye movement dissociations and furthers our understanding of the brain pathways underlying vision and movement with and without awareness. Copyright © 2015 Elsevier Ltd. All rights reserved.

From neuro-functional to neuro-computational models. Comment on "The quartet theory of human emotions: An integrative and neurofunctional model" by S. Koelsch et al.

NASA Astrophysics Data System (ADS)

Briesemeister, Benny B.

2015-06-01

Historically, there has been a strong opposition between psychological theories of human emotion that suggest a limited number of distinct functional categories, such as anger, fear, happiness and so forth (e.g. [1]), and theories that suggest processing along affective dimensions, such as valence and arousal (e.g. [2]). Only few current models acknowledge that both of these perspectives seem to be legitimate [3], and at their core, even fewer models connect these insights with knowledge about neurophysiology [4]. In this regard, the Quartet Theory of Human Emotions (QTHE) [5] makes a very important and useful contribution to the field of emotion research - but in my opinion, there is still at least one more step to go.

The effects of violent media content on aggression.

PubMed

Bender, Patrick K; Plante, Courtney; Gentile, Douglas A

2018-02-01

Decades of research have shown that violent media exposure is one risk factor for aggression. This review presents findings from recent cross-sectional, experimental, and longitudinal studies, demonstrating the triangulation of evidence within the field. Importantly, this review also illustrates how media violence research has started to move away from merely establishing the existence of media effects and instead has begun to investigate the mechanisms underlying these effects and their limitations. Such studies range from investigations into cross-cultural differences to neurophysiological effects, and the interplay between media, individual, and contextual factors. Although violent media effects have been well-established for some time, they are not monolithic, and recent findings continue to shed light on the nuances and complexities of such effects. Copyright © 2017 Elsevier Ltd. All rights reserved.

Attention Deficit Hyperactivity Disorder

PubMed Central

Matthews, Marguerite; Nigg, Joel T.

2014-01-01

Over the last two decades, there have been numerous technical and methodological advances available to clinicians and researchers to better understand attention deficit hyperactivity disorder (ADHD) and its etiology. Despite the growing body of literature investigating the disorder’s pathophysiology, ADHD remains a complex psychiatric disorder to characterize. This chapter will briefly review the literature on ADHD, with a focus on its history, the current genetic insights, neurophysiologic theories, and the use of neuroimaging to further understand the etiology. We address some of the major concerns that remain unclear about ADHD, including subtype instability, heterogeneity, and the underlying neural correlates that define the disorder. We highlight that the field of ADHD is rapidly evolving; the descriptions provided here will hopefully provide a sturdy foundation for which to build and improve our understanding of the disorder. PMID:24214656

On the origins of anticipation as an evolutionary framework: functional systems perspective

NASA Astrophysics Data System (ADS)

Kurismaa, Andres

2015-08-01

This paper discusses the problem of anticipation from an evolutionary and systems-theoretical perspective, developed in the context of Russian/Soviet evolutionary biological and neurophysiological schools in the early and mid-twentieth century. On this background, an outline is given of the epigenetic interpretation of anticipatory capacities formulated and substantiated by the eminent Russian neurophysiologist academician Peter K. Anokhin in the framework of functional systems theory. It is considered that several key positions of this theory are well confirmed by recent evidence on anticipation as an evolutionarily basic adaptive capacity, possibly inherent to the organization of life. In the field of neuroscience, the theory of functional systems may potentially facilitate future studies at the intersection of learning, development and evolution by representing an integrative approach to the problem of anticipation.

Daydreaming, Thought Blocking and Strudels in the Taskless, Resting Human Brain's Magnetic Fields

NASA Astrophysics Data System (ADS)

Mandell, Arnold J.; Selz, Karen A.; Aven, John; Holroyd, Tom; Coppola, Richard

2011-04-01

The incidence, i(S), and duration, l(S), of transient, intermittent, hierarchical vorticities, strudels, S, in magnetic flux fluctuations, were computed from MEG records. from 91 task-free resting subjects. The MEG's i(S) and l(S) manifested characteristic times and entropic sensitivity resembling those reported in psychological studies of daydreaming and task-unrelated thoughts, TUTs. Transient reduction or absences of strudels can be found in patients with syndromes characterized by thought blocking. Positive ergodic single orbit measures of expansiveness and mixing predict i(S) and l(S). An analogy with the relationship between intermittent pontine-geniculate-occipital waves and dreaming is made to strudels with daydreaming. Both can be interpreted as neurophysiological correlates of the spontaneous intrusions into consciousness of the never idle unconscious mind.

Invertebrate neuroscience and CephsInAction at the Mediterranean Society for Neuroscience Meeting Cagliari 2015.

PubMed

Holden-Dye, Lindy; Fiorito, Graziano; Ponte, Giovanna

2015-12-01

Invertebrate neuroscience, and in particular cephalopod research, is well represented in the Mediterranean region. Therefore, the recent meeting of the Mediterranean Society for Neuroscience in Santa Margherita di Pula, Sardinia (12-15 June 2015) provided an excellent opportunity for invertebrate contributions. Furthermore, the Chair of an EU COST Action for cephalopod research (FA1301; www.cephsinaction.org ), Giovanna Ponte, together with Graziano Fiorito from the Stazione Zoologica, Naples, aligned a meeting of research groups working in the field of cephalopod neurophysiology from across Europe to coincide with the neuroscience meeting. This provided an exciting forum for exchange of ideas. Here we provide brief highlights of both events and an explanation of the activities of the COST Action for the broader invertebrate neuroscience community.

Neuronal and oscillatory activity during reward processing in the human ventral striatum.

PubMed

Lega, Bradley C; Kahana, Michael J; Jaggi, Jurg; Baltuch, Gordon H; Zaghloul, Kareem

2011-11-16

Accumulated evidence from animal studies implicates the ventral striatum in the processing of reward information. Recently, deep brain stimulation (DBS) surgery has enabled researchers to analyze neurophysiological recordings from humans engaged in reward tasks. We present data recorded from the human ventral striatum during deep brain stimulation surgery as a participant played a video game coupled to the receipt of visual reward images. To our knowledge, we identify the first instances of reward-sensitive single unit activity in the human ventral striatum. Local field potential data suggest that alpha oscillations are sensitive to positive feedback, whereas beta oscillations exhibit significantly higher power during unrewarded trials. We report evidence of alpha-gamma cross-frequency coupling that differentiates between positive and negative feedback. © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Acting without seeing: Eye movements reveal visual processing without awareness Miriam Spering & Marisa Carrasco

PubMed Central

Spering, Miriam; Carrasco, Marisa

2015-01-01

Visual perception and eye movements are considered to be tightly linked. Diverse fields, ranging from developmental psychology to computer science, utilize eye tracking to measure visual perception. However, this prevailing view has been challenged by recent behavioral studies. We review converging evidence revealing dissociations between the contents of perceptual awareness and different types of eye movements. Such dissociations reveal situations in which eye movements are sensitive to particular visual features that fail to modulate perceptual reports. We also discuss neurophysiological, neuroimaging and clinical studies supporting the role of subcortical pathways for visual processing without awareness. Our review links awareness to perceptual-eye movement dissociations and furthers our understanding of the brain pathways underlying vision and movement with and without awareness. PMID:25765322

Memory as Perception of the Past: Compressed Time inMind and Brain.

PubMed

Howard, Marc W

2018-02-01

In the visual system retinal space is compressed such that acuity decreases further from the fovea. Different forms of memory may rely on a compressed representation of time, manifested as decreased accuracy for events that happened further in the past. Neurophysiologically, "time cells" show receptive fields in time. Analogous to the compression of visual space, time cells show less acuity for events further in the past. Behavioral evidence suggests memory can be accessed by scanning a compressed temporal representation, analogous to visual search. This suggests a common computational language for visual attention and memory retrieval. In this view, time functions like a scaffolding that organizes memories in much the same way that retinal space functions like a scaffolding for visual perception. Copyright © 2017 Elsevier Ltd. All rights reserved.

Subthalamic nucleus deep brain stimulation for Parkinson's disease: evidence for effectiveness and limitations from 12 years' experience.

PubMed

Chan, Anne Y Y; Yeung, Jonas H M; Mok, Vincent C T; Ip, Vincent H L; Wong, Adrian; Kuo, S H; Chan, Danny T M; Zhu, X L; Wong, Edith; Lau, Claire K Y; Wong, Rosanna K M; Tang, Venus; Lau, Christine; Poon, W S

2014-12-01

To present the result and experience of subthalamic nucleus deep brain stimulation for Parkinson's disease. Case series. Prince of Wales Hospital, Hong Kong. A cohort of patients with Parkinson's disease received subthalamic nucleus deep brain stimulation from September 1998 to January 2010. Patient assessment data before and after the operation were collected prospectively. Forty-one patients (21 male and 20 female) with Parkinson's disease underwent bilateral subthalamic nucleus deep brain stimulation and were followed up for a median interval of 12 months. For the whole group, the mean improvements of Unified Parkinson's Disease Rating Scale (UPDRS) parts II and III were 32.5% and 31.5%, respectively (P<0.001). Throughout the years, a multidisciplinary team was gradually built. The deep brain stimulation protocol evolved and was substantiated by updated patient selection criteria and outcome assessment, integrated imaging and neurophysiological targeting, refinement of surgical technique as well as the accumulation of experience in deep brain stimulation programming. Most of the structural improvement occurred before mid-2005. Patients receiving the operation before June 2005 (19 cases) and after (22 cases) were compared; the improvements in UPDRS part III were 13.2% and 55.2%, respectively (P<0.001). There were three operative complications (one lead migration, one cerebral haematoma, and one infection) in the group operated on before 2005. There was no operative mortality. The functional state of Parkinson's disease patients with motor disabilities refractory to best medical treatment improved significantly after subthalamic nucleus deep brain stimulation. A dedicated multidisciplinary team building, refined protocol for patient selection and assessment, improvement of targeting methods, meticulous surgical technique, and experience in programming are the key factors contributing to the improved outcome.

A solid-state hybrid density functional theory study of Prussian blue analogues and related chlorides at pressure

NASA Astrophysics Data System (ADS)

Middlemiss, Derek S.; Lawton, Lorreta M.; Wilson, Chick C.

2008-08-01

The variations with pressure in the structural, electronic and magnetic properties of a series of Prussian blue analogues (PBAs) KIMII[CrIII(CN)6] (M = VII, MnII and NiII) and associated isomorphous chlorides KIMIICrIIICl6 are investigated within a series of solid-state hybrid density functional calculations. The sensitivity of the computed properties to the choice of Hamiltonian is tested by application of functionals containing 35%, 65% and 100% admixtures of Fock exchange. Magnetic coupling constants (J) are obtained at a range of cell volumes (V), with fits of the Bloch relationship (J \\propto V^{-\\varepsilon } , ɛ typically 3-4) yielding exponents ɛ in the ranges 5.16-6.34, 8.48-12.07 and 4.00-4.51 for the antiferromagnetic (AF) VIICrIII-, ferrimagnetic (FI) MnIICrIII- and ferromagnetic (FO) NiIICrIII PBAs, respectively; and 3.33-4.99, 1.86-3.09 and 1.65-3.28 for the AF VIICrIII-, FO MnIICrIII- and FO NiIICrIII chlorides, respectively. The MnIICrIII PBA range encloses the high values ɛ~9-10 obtained in a recent joint experimental and theoretical study, and it is suggested that this strong magnetostructural effect arises due to the presence of competing AF and FO interactions in this material. Estimates of the spin ordering temperatures derived from the combination of the 35%-functional couplings with a mean field approach are in good agreement with experiment in the VIICrIII and NiIICrIII PBAs, but are too low in the MnIICrIII system. The variations with pressure in the structural parameters, charges and spin moments are also detailed, the PBA and chloride energy-volume data yielding bulk moduli in the ranges 39-53 and 36-50 GPa, respectively. Finally, the energies governing CN- ligand isomerization are estimated and successfully interpreted in terms of a simple crystal field stabilization model.

The reliability of axis II of DSM-III.

PubMed

Mellsop, G; Varghese, F; Joshua, S; Hicks, A

1982-10-01

The reliability of the diagnoses of axis II of DSM-III was examined by measuring the levels of agreement among three psychiatrists who independently examined the same patients in everyday clinical settings. The kappa coefficient levels were lower than those reported from the field trials.

PRESERVATION OF SULFIDIC WATERS CONTAINING DISSOLVED AS (III)

EPA Science Inventory

Field samples for arsenic analyses are commonly preserved by acidification with hydrochloric or nitric acid. In some suboxic samples, appreciable concentrations of H2S and HS- are observed due to the microbial respiration of sulfate-reducing bacteria. If both As(III) and sulfid...

System III variations in apparent distance of Io plasma torus from Jupiter

NASA Technical Reports Server (NTRS)

Dessler, A. J.; Sandel, B. R.

1992-01-01

System III variations in apparent distance of the Io plasma torus from Jupiter are examined on the basis of data obtained from UVS scans across Jupiter's satellite system. The displacement of the dawn and dusk ansae are found to be unexpectedly complex. The displacements are unequal and both ansae are in motion with the motion of the approaching ansa being the lesser of the two. The radial motions, as measured from either the center of Jupiter or the offset-tilted dipole, are of unequal magnitude and have the System III periodicity. It is concluded that the cross-tail electric field that causes these torus motions is concentrated on the dusk ansa, varied with the System III period, and shows magnetic-anomaly phase control. It is found that the dawn-dust asymmetry in brightness is not explained simply by the cross-tail electric field. It is concluded that there is a heating mechanism that causes the dusk side of the Io plasma torus to be brighter than the dawn side.

FIELD EVALUATION OF LOW-EMISSION COAL BURNER TECHNOLOGY ON UTILITY BOILERS VOLUME III. FIELD EVALUATIONS

EPA Science Inventory

The report gives results of field tests conducted to determine the emission characteristics of a Babcock and Wilcox Circular burner and Dual Register burner (DRB). The field tests were performed at two utility boilers, generally comparable in design and size except for the burner...

47 CFR 73.686 - Field strength measurements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... earth radius, of the largest available scale. (c) Collection of field strength data to determine... through the measurement area. (iii) Antenna elevation. When field strength is being measured for a one....686 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO...

47 CFR 73.686 - Field strength measurements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... earth radius, of the largest available scale. (c) Collection of field strength data to determine... through the measurement area. (iii) Antenna elevation. When field strength is being measured for a one....686 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO...

47 CFR 73.686 - Field strength measurements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... earth radius, of the largest available scale. (c) Collection of field strength data to determine... through the measurement area. (iii) Antenna elevation. When field strength is being measured for a one....686 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO...

47 CFR 73.686 - Field strength measurements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... earth radius, of the largest available scale. (c) Collection of field strength data to determine... through the measurement area. (iii) Antenna elevation. When field strength is being measured for a one....686 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO...

Sweat testing to evaluate autonomic function

PubMed Central

Illigens, Ben M.W.; Gibbons, Christopher H.

2011-01-01

Sudomotor dysfunction is one of the earliest detectable neurophysiologic abnormalities in distal small fiber neuropathy. Traditional neurophysiologic measurements of sudomotor function include thermoregulatory sweat testing (TST), quantitative sudomotor axon reflex testing (QSART), silicone impressions, the sympathetic skin response (SSR), and the recent addition of quantitative direct and indirect axon reflex testing (QDIRT). These testing techniques, when used in combination, can detect and localized pre- and postganglionic lesions, can provide early diagnosis of sudomotor dysfunction and can monitor disease progression or disease recovery. In this article, we review the common tests available for assessment of sudomotor function, detail the testing methodology, review the limitations and provide examples of test results. PMID:18989618

Conceptual Coordination Bridges Information Processing and Neurophysiology

NASA Technical Reports Server (NTRS)

Clancey, William J.; Norrig, Peter (Technical Monitor)

2000-01-01

Information processing theories of memory and skills can be reformulated in terms of how categories are physically and temporally related, a process called conceptual coordination. Dreaming can then be understood as a story understanding process in which two mechanisms found in everyday comprehension are missing: conceiving sequences (chunking categories in time as a categorization) and coordinating across modalities (e.g., relating the sound of a word and the image of its meaning). On this basis, we can readily identify isomorphisms between dream phenomenology and neurophysiology, and explain the function of dreaming as facilitating future coordination of sequential, cross-modal categorization (i.e., REM sleep lowers activation thresholds, "unlearning").

Neurophysiology of arthritis pain.

PubMed

McDougall, Jason J; Linton, Patrick

2012-12-01

Arthritis pain is a complex phenomenon involving intricate neurophysiological processing at all levels of the pain pathway. The treatment options available to alleviate joint pain are fairly limited and most arthritis patients report only modest pain relief with current treatments. A better understanding of the neural mechanisms responsible for musculoskeletal pain and the identification of new targets will help in the development of future pharmacological therapies. This article reviews some of the latest research into factors which contribute to joint pain and covers areas such as cannabinoids, proteinase activated receptors, sodium channels, cytokines and transient receptor potential channels. The emerging hypothesis that osteoarthritis may have a neuropathic component is also discussed.

Neurophysiological evidence for the influence of past experience on figure-ground perception.

PubMed

Trujillo, Logan T; Allen, John J B; Schnyer, David M; Peterson, Mary A

2010-02-10

A fundamental aspect of perceptual organization entails segregating visual input into shaped figures presented against shapeless backgrounds; an outcome termed "figure-ground perception" or "shape assignment." The present study examined how early in processing past experience exerts an influence on shape assignment. Event-related potential (ERP) measures of brain activity were recorded while observers viewed silhouettes of novel objects that differed in whether or not a familiar shape was suggested on the outside-the groundside-of their bounding edges (experimental versus control silhouettes, respectively). Observers perceived both types of silhouettes as novel shapes and were unaware of the familiar shape suggested on the groundside of experimental silhouettes. Nevertheless, we expected that the familiar shape would be implicitly identified early in processing and would compete for figural status with the novel shape on the inside. Early (106-156 ms) ERPs were larger for experimental silhouettes than for control silhouettes lacking familiarity cues. The early ERP difference occurred during a time interval within which edge-segmentation-dependent response differences have been observed in previous neurophysiological investigations of figure-ground perception. These results provide the first neurophysiological evidence for an influence of past experience during the earliest stages of shape assignment.

[The neurodynamic core of consciousness and neural Darwinism].

PubMed

Ibáñez, A

In the last decades, the scientific study of consciousness in the scope of the cognitive neurosciences can be considered one of the greatest challenges of contemporary science. The Gerald Edelman theory of consciousness is one of the most promising and controversial perspectives. This theory stands out by its approach to topics usually rejected by other neurophysiologic theories of consciousness, as the case of the neurophysiologic explanation of qualia. The goal of this paper is to review the dynamic core theory of consciousness, presenting the main features of the theory, analyzing the explanation strategies, their empirical extensions, and elaborating some critical considerations about the possibility of the neuroscientific study of qualia. The central and additional theoretical components are analyzed, emphasizing its ontological, restrictive and explanatory assumptions. The properties of conscious phenomena and their cerebral correlates as advanced by the theory are described, and finally its experiments and empirical extensions are examined. The explanatory strategies of the theory are analyzed, based on conceptual isomorphism between the phenomenological properties and the neurophysiological and mathematical measures. Some criticisms could be raised about the limitations of the dynamic core theory, especially regarding its account of the so-called 'hard problem' of consciousness or qualia.

The neuroscience of learning.

PubMed

Collins, John W

2007-10-01

Significant advances have been made in understanding the neurophysiological basis of learning, including the discovery of mirror neurons and the role of cyclic adenosine monophosphate (cAMP) responsive element binding (CREB) protein in learning. Mirror neurons help us visually compare an observed activity with a remembered action in our memory, an ability that helps us imitate and learn through watching. Long-term potentiation, the Hebb rule, and CREB protein are associated with the formation of long-term memories. Conversely, protein phosphatase 1 and glucocorticoids are neurophysiological phenomena that limit what can be learned and cause forgetfulness. Gardner's theory of multiple intelligences contends that different areas of the brain are responsible for different competencies that we all possess to varying degrees. These multiple intelligences can be used as strategies for improved learning. Repeating material, using mnemonics, and avoiding overwhelming stress are other strategies for improving learning. Imaging studies have shown that practice with resultant learning results in significantly less use of brain areas, indicating that the brain becomes more efficient. Experts have advantages over novices, including increased cognitive processing efficiency. Nurses are in a unique position to use their understanding of neurophysiological principles to implement better educational strategies to provide quality education to patients and others.

What do we really know about newborn infant pain?

PubMed

Fitzgerald, Maria

2015-12-01

What is the topic of this review? Pain in infancy. What advances does it highlight? New neurophysiological research on pain processing in the human infant brain. Increased awareness of pain in the newborn has led to the development of numerous assessment tools for use in neonatal intensive care units. Here, I argue that we still know too little about the neurophysiological basis for infant pain to interpret data from clinical observational measures. With increased understanding of how the neural activity and CNS connections that underlie pain behaviour and perception develop in the newborn will come better measurement and treatment of their pain. This review focuses upon two interconnected nociceptive circuits, the spinal cord dorsal horn and the somatosensory cortex in the brain, to highlight what we know and what we do not know about infant pain. The effectiveness of oral sucrose, widely used in clinical practice to relieve infant pain, is discussed as a specific example of what we do not know. This 'hot topic review' highlights the importance of new laboratory-based neurophysiological research for the treatment of newborn infant pain. © 2015 The Authors. Experimental Physiology © 2015 The Physiological Society.

Exploring Neuro-Physiological Correlates of Drivers' Mental Fatigue Caused by Sleep Deprivation Using Simultaneous EEG, ECG, and fNIRS Data

PubMed Central

Ahn, Sangtae; Nguyen, Thien; Jang, Hyojung; Kim, Jae G.; Jun, Sung C.

2016-01-01

Investigations of the neuro-physiological correlates of mental loads, or states, have attracted significant attention recently, as it is particularly important to evaluate mental fatigue in drivers operating a motor vehicle. In this research, we collected multimodal EEG/ECG/EOG and fNIRS data simultaneously to develop algorithms to explore neuro-physiological correlates of drivers' mental states. Each subject performed simulated driving under two different conditions (well-rested and sleep-deprived) on different days. During the experiment, we used 68 electrodes for EEG/ECG/EOG and 8 channels for fNIRS recordings. We extracted the prominent features of each modality to distinguish between the well-rested and sleep-deprived conditions, and all multimodal features, except EOG, were combined to quantify mental fatigue during driving. Finally, a novel driving condition level (DCL) was proposed that distinguished clearly between the features of well-rested and sleep-deprived conditions. This proposed DCL measure may be applicable to real-time monitoring of the mental states of vehicle drivers. Further, the combination of methods based on each classifier yielded substantial improvements in the classification accuracy between these two conditions. PMID:27242483

Nascent body ego: metapsychological and neurophysiological aspects.

PubMed

Lehtonen, Johannes; Partanen, Juhani; Purhonen, Maija; Valkonen-Korhonen, Minna; Kononen, Mervi; Saarikoski, Seppo; Launiala, Kari

2006-10-01

For Freud, body ego was the organizing basis of the structural theory. He defined it as a psychic projection of the body surface. Isakower's and Lewin's classical findings suggest that the body surface experiences of nursing provide the infant with sensory-affective stimulation that initiates a projection of sensory processes towards the psychic realm. During nursing, somato-sensory, gustatory and olfactory modalities merge with a primitive somatic affect of satiation, whereas auditory modality is involved more indirectly and visual contact more gradually. Repeated regularly, such nascent experiences are likely to play a part in the organization of the primitive protosymbolic mental experience. In support of this hypothesis, the authors review findings from a neurophysiological study of infants before, during and after nursing. Nursing is associated with a significant amplitude change in the newborn electroencephalogram (EEG), which wanes before the age of 3 months, and is transformed at the age of 6 months into rhythmic 3-5 Hz hedonic theta-activity. Sucking requires active physiological work, which is shown in a regular rise in heart rate. The hypothesis of a sensory-affective organization of the nascent body ego, enhanced by nursing and active sucking, seems concordant with neurophysiological phenomena related to nursing.

Reduced mismatch negativity in mild cognitive impairment: associations with neuropsychological performance.

PubMed

Mowszowski, Loren; Hermens, Daniel F; Diamond, Keri; Norrie, Louisa; Hickie, Ian B; Lewis, Simon J G; Naismith, Sharon L

2012-01-01

Mild cognitive impairment (MCI) refers to a transitory state between healthy aging and dementia. Biomarkers are needed to facilitate early identification of MCI and predict progression to dementia. One potential neurophysiological biomarker, mismatch negativity (MMN), is an event-related potential reflecting fundamental, pre-attentive cognitive processes. MMN is reduced in normal aging and dementia and in neuropsychiatric samples and is associated with verbal memory deficits and poor executive functioning. This study aimed to investigate auditory MMN and its relationship to neuropsychological performance in MCI. Twenty-eight MCI participants and fourteen controls, aged ≥50 years, underwent neurophysiological and neuropsychological assessment, and completed questionnaires pertaining to disability. Relative to controls, the MCI group demonstrated reduced temporal MMN amplitude (p < 0.01). Reduced right temporal MMN was significantly associated with poorer verbal learning (r = 0.496; p < 0.01) and reduced left temporal MMN was significantly associated with increased self-reported disability (r = -0.419; p < 0.05). These results indicate that patients with MCI exhibit altered pre-attentive information processing, which in turn is associated with memory and psychosocial deficits. These findings overall suggest that MMN may be a viable neurophysiological biomarker of underlying disease in this 'at risk' group.

Dynamic publication model for neurophysiology databases.

PubMed

Gardner, D; Abato, M; Knuth, K H; DeBellis, R; Erde, S M

2001-08-29

We have implemented a pair of database projects, one serving cortical electrophysiology and the other invertebrate neurones and recordings. The design for each combines aspects of two proven schemes for information interchange. The journal article metaphor determined the type, scope, organization and quantity of data to comprise each submission. Sequence databases encouraged intuitive tools for data viewing, capture, and direct submission by authors. Neurophysiology required transcending these models with new datatypes. Time-series, histogram and bivariate datatypes, including illustration-like wrappers, were selected by their utility to the community of investigators. As interpretation of neurophysiological recordings depends on context supplied by metadata attributes, searches are via visual interfaces to sets of controlled-vocabulary metadata trees. Neurones, for example, can be specified by metadata describing functional and anatomical characteristics. Permanence is advanced by data model and data formats largely independent of contemporary technology or implementation, including Java and the XML standard. All user tools, including dynamic data viewers that serve as a virtual oscilloscope, are Java-based, free, multiplatform, and distributed by our application servers to any contemporary networked computer. Copyright is retained by submitters; viewer displays are dynamic and do not violate copyright of related journal figures. Panels of neurophysiologists view and test schemas and tools, enhancing community support.

ACQ4: an open-source software platform for data acquisition and analysis in neurophysiology research

PubMed Central

Campagnola, Luke; Kratz, Megan B.; Manis, Paul B.

2014-01-01

The complexity of modern neurophysiology experiments requires specialized software to coordinate multiple acquisition devices and analyze the collected data. We have developed ACQ4, an open-source software platform for performing data acquisition and analysis in experimental neurophysiology. This software integrates the tasks of acquiring, managing, and analyzing experimental data. ACQ4 has been used primarily for standard patch-clamp electrophysiology, laser scanning photostimulation, multiphoton microscopy, intrinsic imaging, and calcium imaging. The system is highly modular, which facilitates the addition of new devices and functionality. The modules included with ACQ4 provide for rapid construction of acquisition protocols, live video display, and customizable analysis tools. Position-aware data collection allows automated construction of image mosaics and registration of images with 3-dimensional anatomical atlases. ACQ4 uses free and open-source tools including Python, NumPy/SciPy for numerical computation, PyQt for the user interface, and PyQtGraph for scientific graphics. Supported hardware includes cameras, patch clamp amplifiers, scanning mirrors, lasers, shutters, Pockels cells, motorized stages, and more. ACQ4 is available for download at http://www.acq4.org. PMID:24523692

The biophysical bases of will-less behaviors

PubMed Central

Perez Velazquez, José L.

2012-01-01

Are there distinctions at the neurophysiological level that correlate with voluntary and involuntary actions? Whereas the wide variety of involuntary behaviors (and here mostly the deviant or pathological ones will be considered) will necessarily be represented at some biophysical level in nervous system activity–for after all those cellular activity patterns manifest themselves as behaviors and thus there will be a multiplicity of them–there could be some general tendencies to be discerned amongst that assortment. Collecting observations derived from neurophysiological activity associated with several pathological conditions characterized by presenting will-less actions such as Parkinson's disease, seizures, alien hand syndrome and tics, it is proposed that a general neurophysiologic tendency of brain activity that correlates with involuntary actions is higher than normal synchrony in specific brain cell networks, depending upon the behavior in question. Wilful, considered normal behavior, depends on precise coordination of the collective activity in cell ensembles that may be lost, or diminished, when there are tendencies toward more than normal or aberrant synchronization of cellular activity. Hence, rapid fluctuations in synchrony is associated with normal actions and cognition while less variability in brain recordings particularly with regards to synchronization could be a signature of unconscious and deviant behaviors in general. PMID:23109920

Pain, dissociation and subliminal self-representations.

PubMed

Bob, Petr

2008-03-01

According to recent evidence, neurophysiological processes coupled to pain are closely related to the mechanisms of consciousness. This evidence is in accordance with findings that changes in states of consciousness during hypnosis or traumatic dissociation strongly affect conscious perception and experience of pain, and markedly influence brain functions. Past research indicates that painful experience may induce dissociated state and information about the experience may be stored or processed unconsciously. Reported findings suggest common neurophysiological mechanisms of pain and dissociation and point to a hypothesis of dissociation as a defense mechanism against psychological and physical pain that substantially influences functions of consciousness. The hypothesis is also supported by findings that information can be represented in the mind/brain without the subject's awareness. The findings of unconsciously present information suggest possible binding between conscious contents and self-functions that constitute self-representational dimensions of consciousness. The self-representation means that certain inner states of own body are interpreted as mental and somatic identity, while other bodily signals, currently not accessible to the dominant interpreter's access are dissociated and may be defined as subliminal self-representations. In conclusion, the neurophysiological aspects of consciousness and its integrative role in the therapy of painful traumatic memories are discussed.

Cells, circuits, and choices: social influences on perceptual decision making.

PubMed

Mojzisch, Andreas; Krug, Kristine

2008-12-01

Making decisions is an integral part of everyday life. Social psychologists have demonstrated in many studies that humans' decisions are frequently and strongly influenced by the opinions of others--even in simple perceptual decisions, where, for example, participants have to judge what an image looks like. However, because the effect of other people's opinions on decision making has remained largely unaddressed by the neuroimaging and neurophysiology literature, we are only beginning to understand how social influence is integrated into the decision-making process. We put forward the thesis that by probing the neurophysiology of social influence with perceptual decision-making tasks similar to those used in the seminal work of Asch (1952, 1956), this gap could be remedied. Perceptual paradigms are already widely used to probe neuronal mechanisms of decision making in nonhuman primates. There is also increasing evidence about how nonhuman primates' behavior is influenced by observing conspecifics. The high spatial and temporal resolution of neurophysiological recordings in awake monkeys could provide insight into where and how social influence modulates decision making, and thus should enable us to develop detailed functional models of the neural mechanisms that support the integration of social influence into the decision-making process.

New Tunneling Features in Polar III-Nitride Resonant Tunneling Diodes

NASA Astrophysics Data System (ADS)

Encomendero, Jimy; Faria, Faiza Afroz; Islam, S. M.; Protasenko, Vladimir; Rouvimov, Sergei; Sensale-Rodriguez, Berardi; Fay, Patrick; Jena, Debdeep; Xing, Huili Grace

2017-10-01

For the past two decades, repeatable resonant tunneling transport of electrons in III-nitride double barrier heterostructures has remained elusive at room temperature. In this work we theoretically and experimentally study III-nitride double-barrier resonant tunneling diodes (RTDs), the quantum transport characteristics of which exhibit new features that are unexplainable using existing semiconductor theory. The repeatable and robust resonant transport in our devices enables us to track the origin of these features to the broken inversion symmetry in the uniaxial crystal structure, which generates built-in spontaneous and piezoelectric polarization fields. Resonant tunneling transport enabled by the ground state as well as by the first excited state is demonstrated for the first time over a wide temperature window in planar III-nitride RTDs. An analytical transport model for polar resonant tunneling heterostructures is introduced for the first time, showing a good quantitative agreement with experimental data. From this model we realize that tunneling transport is an extremely sensitive measure of the built-in polarization fields. Since such electric fields play a crucial role in the design of electronic and photonic devices, but are difficult to measure, our work provides a completely new method to accurately determine their magnitude for the entire class of polar heterostructures.

Effect of Ligand Field Tuning on the SMM Behavior for Three Related Alkoxide-Bridged Dysprosium Dimers.

PubMed

Peng, Yan; Mereacre, Valeriu; Baniodeh, Amer; Lan, Yanhua; Schlageter, Martin; Kostakis, George E; Powell, Annie K

2016-01-04

The synthesis and characterization of three Dy2 compounds, [Dy2(HL1)2(NO3)4] (1), [Dy2(L2)2(NO3)4] (2), and [Dy2(HL3)2(NO3)4] (3), formed using related tripodal ligands with a central tertiary amine bearing picolyl and alkoxy arms, 2-[(2-hydroxy-ethyl)-pyridin-2-ylmethylamino]-ethanol (H2L1), 2-(bis-pyridin-2-ylmethylamino)-ethanol (HL2), and 2-(bis-pyridin-2-ylmethylamino)-propane-1,3-diol (H2L3), are reported. The compounds are rare examples of alkoxide-bridged {Dy2} complexes and display capped square antiprism coordination geometry around each Dy(III) ion. Changes in the ligand field environment around the Dy(III) ions brought about through variations in the ligand donors can be gauged from the magnetic properties, with compounds 1 and 2 showing antiparallel coupling between the Dy(III) ions and 3 showing parallel coupling. Furthermore, slow relaxation of the magnetization typical of SMM behavior could be observed for compounds 2 and 3, suggesting that small variations in the ligand field can have a significant influence on the slow relaxation processes responsible for SMM behavior of Dy(III)-based systems.

Positions of type II fundamental and harmonic sources in the 30-100 MHZ range

NASA Technical Reports Server (NTRS)

Sawant, H. S.; Gergely, T. E.; Kundu, M. R.

1982-01-01

An excellent example of a type III-V burst followed by a type II burst with fundamental and harmonic bands was observed on June 18, 1979 at the Clark Lake Radio Observatory. The observations are described in detail and their implications are discussed with regard to the problem of directionality with respect to the magnetic field lines of the collisionless MHD shock wave generated at the start of the flash phase. It is found that the positions of type III and type II (F) bursts at a number of frequencies are essentially the same, which implies that the shock responsible for the type II radiation follows the path of the type III exciter, that is, the shock propagates along the open field lines.

A DFT based ligand field model for magnetic exchange coupling in transition metal dimer complexes:. (ii) application to magnetic systems with more than one unpaired electron per site

NASA Astrophysics Data System (ADS)

Atanasov, M.; Daul, C. A.

2003-11-01

The DFT based ligand field model for magnetic exchange coupling proposed recently, has been extended to systems containing more than one unpaired electron per site. The guidelines for this extension are described using a model example - the complex (NH 3) 3Cr III(OH) 3Cr III (NH 3) 33+. The exchange Hamiltonian, H ex=-J 12S1S2 has been simplified using symmetry principles, i.e. utilizing the D 3h(C 3v) Cr III - dimer(site) symmetry. Both antiferro- and ferromagnetic exchange coupling constants are found to yield important contributions to the value of the (negative, antiferromagnetic) exchange coupling constant in good agreement with experiment.

Antibiotic resistance marker genes as environmental pollutants in GMO-pristine agricultural soils in Austria.

PubMed

Woegerbauer, Markus; Zeinzinger, Josef; Gottsberger, Richard Alexander; Pascher, Kathrin; Hufnagl, Peter; Indra, Alexander; Fuchs, Reinhard; Hofrichter, Johannes; Kopacka, Ian; Korschineck, Irina; Schleicher, Corina; Schwarz, Michael; Steinwider, Johann; Springer, Burkhard; Allerberger, Franz; Nielsen, Kaare M; Fuchs, Klemens

2015-11-01

Antibiotic resistance genes may be considered as environmental pollutants if anthropogenic emission and manipulations increase their prevalence above usually occurring background levels. The prevalence of aph(3')-IIa/nptII and aph(3')-IIIa/nptIII - frequent marker genes in plant biotechnology conferring resistance to certain aminoglycosides - was determined in Austrian soils from 100 maize and potato fields not yet exposed to but eligible for GMO crop cultivation. Total soil DNA extracts were analysed by nptII/nptIII-specific TaqMan real time PCR. Of all fields 6% were positive for nptII (median: 150 copies/g soil; range: 31-856) and 85% for nptIII (1190 copies/g soil; 13-61600). The copy-number deduced prevalence of nptIII carriers was 14-fold higher compared to nptII. Of the cultivable kanamycin-resistant soil bacteria 1.8% (95% confidence interval: 0-3.3%) were positive for nptIII, none for nptII (0-0.8%). The nptII-load of the studied soils was low rendering nptII a typical candidate as environmental pollutant upon anthropogenic release into these ecosystems. Copyright © 2015 Elsevier Ltd. All rights reserved.

Structural study of Na2O-B2O3-SiO2 glasses from molecular simulations using a polarizable force field.

PubMed

Pacaud, Fabien; Delaye, Jean-Marc; Charpentier, Thibault; Cormier, Laurent; Salanne, Mathieu

2017-10-28

Sodium borosilicate glasses Na 2 O-B 2 O 3 -SiO 2 (NBS) are complex systems from a structural point of view. Three main building units are present: tetrahedral SiO 4 and BO 4 (B IV ) and triangular BO 3 (B III ). One of the salient features of these compounds is the change of the B III /B IV ratio with the alkali concentration, which is very difficult to capture in force fields-based molecular dynamics simulations. In this work, we develop a polarizable force field that is able to reproduce the boron coordination and more generally the structure of several NBS systems in the glass and in the melt. The parameters of the potential are fitted from density functional theory calculations only, in contrast with the existing empirical potentials for NBS systems. This ensures a strong improvement on the transferability of the parameters from one composition to another. Using this new force field, the structure of NBS systems is validated against neutron diffraction and nuclear magnetic resonance experiments. A special focus is given to the distribution of B III /B IV with respect to the composition and the temperature.

Modular Carbon and Gold Nanoparticles for High Field MR Imaging and Theranostics

NASA Astrophysics Data System (ADS)

Rammohan, Nikhil

The ability to track labeled cancer cells in vivo would allow researchers to study their distribution, growth and metastatic potential within the intact organism. Magnetic Resonance (MR) imaging is invaluable for tracking cancer cells in vivo as it benefits from high spatial resolution and absence of ionizing radiation. However, many MR contrast agents (CAs) required to label cells either do not significantly accumulate in cells or are not biologically compatible for translational studies. Accordingly, we have developed carbon- and gold-nanoparticles coupled to gadolinium(III) [Gd(III)] chelates for T1-weighted MR imaging that demonstrated remarkable properties for cell tracking in vitro and in vivo.. We created nanodiamond-Gd(III) aggregates (NDG) by peptide coupling Gd(III) chelates to aminated nanodiamonds. NDG had high relaxivity independent of field strength (unprecedented for Gd(III)-nanoparticle conjugates), and demonstrated a 300-fold increase in cellular delivery of Gd(III) compared to clinical Gd(III) chelates. Further, we were able to monitor the tumor growth of NDG-labeled flank tumors by T1-weighted MRI for 26 days in vivo, longer than reported for other MR CAs or nuclear agents. Further, theranostic nanodiamond-gadolinium(III)-doxorubicin (ND-Gd-Dox) aggregates were generated by conjugating doxorubicin (ND-Gd-Dox), which enabled efficient cancer chemotherapy in breast cancer cells. Further, we synthesized Gd(III)-gold nanoconjugates (Gd AuNPs) with varied chelate structure and nanoparticle-chelate linker length. Significantly enhanced cell labeling was demonstrated compared to previous gadolinium-gold-DNA nanoconstructs. Differences in Gd(III) loading, surface packing and cell uptake were observed between four different Gd AuNP formulations suggesting that linker length and surface charge play an important role in cell labeling. The best performing Gd AuNPs afforded 23.6 +/- 3.6 fmol of Gd(III) per cell at an incubation concentration of 27.5 microM. This efficiency of Gd(III) payload delivery (Gd(III)/cell normalized to dose) exceeds that of previously Gd(III)-Au conjugates and most other Gd(III)-nanoparticle formulations. Finally, Gd AuNPs were the first MR CAs of any type to effectively image the pancreas in vivo. . In summary, both Gd AuNPs and NDG support future MR-mediated cell tracking and theranostic applications in whole-animal models.

14 CFR 1259.101 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... definitions shall apply: (a) Field related to space means any academic discipline or field of study (including the physical, natural and biological sciences, and engineering, space technology, education, economics... activities in the fields related to space: (i) Research; (ii) Training; or (iii) Advisory services. (j) Space...

Gd(III)-Gd(III) EPR distance measurements--the range of accessible distances and the impact of zero field splitting.

PubMed

Dalaloyan, Arina; Qi, Mian; Ruthstein, Sharon; Vega, Shimon; Godt, Adelheid; Feintuch, Akiva; Goldfarb, Daniella

2015-07-28

Gd(III) complexes have emerged as spin labels for distance determination in biomolecules through double-electron-electron resonance (DEER) measurements at high fields. For data analysis, the standard approach developed for a pair of weakly coupled spins with S = 1/2 was applied, ignoring the actual properties of Gd(III) ions, i.e. S = 7/2 and ZFS (zero field splitting) ≠ 0. The present study reports on a careful investigation on the consequences of this approach, together with the range of distances accessible by DEER with Gd(III) complexes as spin labels. The experiments were performed on a series of specifically designed and synthesized Gd-rulers (Gd-PyMTA-spacer-Gd-PyMTA) covering Gd-Gd distances of 2-8 nm. These were dissolved in D2O-glycerol-d8 (0.03-0.10 mM solutions) which is the solvent used for the corresponding experiments on biomolecules. Q- and W-band DEER measurements, followed by data analysis using the standard data analysis approach, used for S = 1/2 pairs gave the distance-distribution curves, of which the absolute maxima agreed very well with the expected distances. However, in the case of the short distances of 2.1 and 2.9 nm, the distance distributions revealed additional peaks. These are a consequence of neglecting the pseudo-secular term in the dipolar Hamiltonian during the data analysis, as is outlined in a theoretical treatment. At distances of 3.4 nm and above, disregarding the pseudo-secular term leads to a broadening of a maximum of 0.4 nm of the distance-distribution curves at half height. Overall, the distances of up to 8.3 nm were determined, and the long evolution time of 16 μs at 10 K indicates that a distance of up to 9.4 nm can be accessed. A large distribution of the ZFS parameter, D, as is found for most Gd(III) complexes in a frozen solution, is crucial for the application of Gd(III) complexes as spin labels for distance determination via Gd(III)-Gd(III) DEER, especially for short distances. The larger ZFS of Gd-PyMTA, in comparison to that of Gd-DOTA, makes Gd-PyMTA a better label for short distances.

Investor Outlook: Focus on Upcoming LCA2 Gene Therapy Phase III Results.

PubMed

Schimmer, Joshua; Breazzano, Steven

2015-09-01

Investor interest in gene therapy has increased substantially over the past few years, and the next major catalyst for the field is likely to be Spark Therapeutics's phase III trial for the treatment of visual impairment caused by RPE65 gene mutations (often referred to as Leber congenital amaurosis type 2, or LCA2, but may include other retinal disorders). Analysis of the approach from the basic genetics, underlying visual mechanisms, clinical data, and commercialization considerations helps frame investor expectations and the potential implications for the broader field.

IN-FIELD PRESERVATION OF ARSENIC SPECIES IN DRINKING WATER USING EDTA

EPA Science Inventory

The two predominant inorganic arsenic species found in drinking waters are As(III) and As(V). As(III) is commonly associated with ground waters while As(V) is associated with surface waters. The efficiency of arsenic removal from a drinking water supply is dependent on the oxid...