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Sample records for derived cumulative somatosensory

  1. Somatosensory deficits.

    Science.gov (United States)

    Klingner, Carsten M; Witte, Otto W

    2018-01-01

    The analysis and interpretation of somatosensory information are performed by a complex network of brain areas located mainly in the parietal cortex. Somatosensory deficits are therefore a common impairment following lesions of the parietal lobe. This chapter summarizes the clinical presentation, examination, prognosis, and therapy of sensory deficits, along with current knowledge about the anatomy and function of the somatosensory system. We start by reviewing how somatosensory signals are transmitted to and processed by the parietal lobe, along with the anatomic and functional features of the somatosensory system. In this context, we highlight the importance of the thalamus for processing somatosensory information in the parietal lobe. We discuss typical patterns of somatosensory deficits, their clinical examination, and how they can be differentiated through a careful neurologic examination that allows the investigator to deduce the location and size of the underlying lesion. In the context of adaption and rehabilitation of somatosensory functions, we delineate the importance of somatosensory information for motor performance and the prognostic evaluation of somatosensory deficits. Finally, we review current rehabilitation approaches for directing cortical reorganization in the appropriate direction and highlight some challenging questions that are unexplored in the field. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. An approach for deriving growth equations for quantities exhibiting cumulative growth based on stochastic interpretation

    Science.gov (United States)

    Moriguchi, Kai

    2018-01-01

    Existing growth equations have been derived by hypothesizing the growth rate as self-referencing. Although that hypothesis is appropriate for quantities with growth directly restricted to themselves, it requires the solution of differential equations that are difficult to be derived. However, for quantities of growth that are indirectly related to themselves, and for quantities that exhibit cumulative growth, such as growth of diameter or volume of trees with lignification, ordinary growth models with assumptions that include self-referencing or implied catabolism terms might not be appropriate. For such quantities, the author proposes an approach for derivation of growth models based on stochastic and microscopic interpretation. Results show that ordinary growth models can be interpreted from the perspective. The approach enables one to derive growth functions without solving differential equations. Based on that approach, growth functions are derived by integrating cumulative distribution functions. Three growth functions are generated using reasonable probability distributions. The fitness of the generated growth functions for real diameter growth data was compared with that of generalized ordinary growth models. Results show that the presented approach has high ability to generate growth models that fit data much better than ordinary growth models for a given number of parameters.

  3. Somatosensory maps.

    Science.gov (United States)

    Harding-Forrester, Samuel; Feldman, Daniel E

    2018-01-01

    Somatosensory areas containing topographic maps of the body surface are a major feature of parietal cortex. In primates, parietal cortex contains four somatosensory areas, each with its own map, with the primary cutaneous map in area 3b. Rodents have at least three parietal somatosensory areas. Maps are not isomorphic to the body surface, but magnify behaviorally important skin regions, which include the hands and face in primates, and the whiskers in rodents. Within each map, intracortical circuits process tactile information, mediate spatial integration, and support active sensation. Maps may also contain fine-scale representations of touch submodalities, or direction of tactile motion. Functional representations are more overlapping than suggested by textbook depictions of map topography. The whisker map in rodent somatosensory cortex is a canonic system for studying cortical microcircuits, sensory coding, and map plasticity. Somatosensory maps are plastic throughout life in response to altered use or injury. This chapter reviews basic principles and recent findings in primate, human, and rodent somatosensory maps. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Potential Health Risks Posed by Plant-Derived Cumulative Neurotoxic Bufadienolides in South Africa

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    Christo Botha

    2016-03-01

    Full Text Available Bufadienolide-type cardiac glycosides have a worldwide distribution and are mainly synthesized by plants, but there are also animal sources. In South Africa, members of three genera of the Crassulaceae (Cotyledon, Tylecodon and Kalanchoe cause a unique chronic form of cardiac glycoside poisoning, predominantly in small stock. This paretic/paralytic condition is referred to as “krimpsiekte”, cotyledonosis or “nenta”. “Krimpsiekte” is a plant poisoning only reported from South Africa and is regarded as the most important plant poisoning of small stock in the semi-arid Little Karoo and southern fringes of the Great Karoo. The toxicosis is caused by cumulative bufadienolides which have neurotoxic properties. Four types of cumulative neurotoxic bufadienolides, namely cotyledoside, and the tyledosides, orbicusides and lanceotoxins, have been isolated. Based on the structure activity relationships and certain toxicokinetic parameters possible reasons for their accumulation are presented. Consumption of edible tissues from animals that have ingested these plants poses a potential risk to humans.

  5. Cumulate xenoliths from St. Vincent, Lesser Antilles Island Arc: a window into upper crustal differentiation of mantle-derived basalts

    Science.gov (United States)

    Tollan, P. M. E.; Bindeman, I.; Blundy, J. D.

    2012-02-01

    In order to shed light on upper crustal differentiation of mantle-derived basaltic magmas in a subduction zone setting, we have determined the mineral chemistry and oxygen and hydrogen isotope composition of individual cumulus minerals in plutonic blocks from St. Vincent, Lesser Antilles. Plutonic rock types display great variation in mineralogy, from olivine-gabbros to troctolites and hornblendites, with a corresponding variety of cumulate textures. Mineral compositions differ from those in erupted basaltic lavas from St. Vincent and in published high-pressure (4-10 kb) experimental run products of a St. Vincent high-Mg basalt in having higher An plagioclase coexisting with lower Fo olivine. The oxygen isotope compositions (δ18O) of cumulus olivine (4.89-5.18‰), plagioclase (5.84-6.28‰), clinopyroxene (5.17-5.47‰) and hornblende (5.48-5.61‰) and hydrogen isotope composition of hornblende (δD = -35.5 to -49.9‰) are all consistent with closed system magmatic differentiation of a mantle-derived basaltic melt. We employed a number of modelling exercises to constrain the origin of the chemical and isotopic compositions reported. δ18OOlivine is up to 0.2‰ higher than modelled values for closed system fractional crystallisation of a primary melt. We attribute this to isotopic disequilibria between cumulus minerals crystallising at different temperatures, with equilibration retarded by slow oxygen diffusion in olivine during prolonged crustal storage. We used melt inclusion and plagioclase compositions to determine parental magmatic water contents (water saturated, 4.6 ± 0.5 wt% H2O) and crystallisation pressures (173 ± 50 MPa). Applying these values to previously reported basaltic and basaltic andesite lava compositions, we can reproduce the cumulus plagioclase and olivine compositions and their associated trend. We conclude that differentiation of primitive hydrous basalts on St. Vincent involves crystallisation of olivine and Cr-rich spinel at depth

  6. Somatosensory abnormalities in knee OA.

    Science.gov (United States)

    Wylde, Vikki; Palmer, Shea; Learmonth, Ian D; Dieppe, Paul

    2012-03-01

    The aim of this study was to use quantitative sensory testing (QST) to explore the range and prevalence of somatosensory abnormalities demonstrated by patients with advanced knee OA. One hundred and seven knee OA patients and 50 age- and sex-matched healthy participants attended a 1-h QST session. Testing was performed on the medial side of the knee and the pain-free forearm. Light-touch thresholds were assessed using von Frey filaments, pressure pain thresholds using a digital pressure algometer, and thermal sensation and pain thresholds using a Thermotest MSA. Significant differences in median threshold values from knee OA patients and healthy participants were identified using Mann-Whitney U-tests. The z-score transformations were used to determine the prevalence of the different somatosensory abnormalities in knee OA patients. Testing identified 70% of knee OA patients as having at least one somatosensory abnormality. Comparison of median threshold values between knee OA patients and healthy participants revealed that patients had localized thermal and tactile hypoaesthesia and pressure hyperalgesia at the osteoarthritic knee. Tactile hypoaesthesia and pressure hyperalgesia were also present at the pain-free forearm. The most prevalent somatosensory abnormalities were tactile hypoaesthesia and pressure hyperalgesia, evident in between 20 and 34% of patients. This study found that OA patients demonstrate an array of somatosensory abnormalities, of which the most prevalent were tactile hypoaesthesia and pressure hyperalgesia. Further research is now needed to establish the clinical implications of these somatosensory abnormalities.

  7. Multichannel recording of tibial-nerve somatosensory evoked potentials

    NARCIS (Netherlands)

    de Wassenberg, W. J. G. van; Kruizinga, W. J.; van der Hoeven, J. H.; Leenders, K. L.; Maurits, N. M.

    2008-01-01

    Study aims. -The topography of the peaks of tibial.-nerve somatosensory evoked potential (SEP) varies among healthy subjects, most likely because of differences in position and orientation of their cortical generator(s). Therefore, amplitude estimation with a standard one- or two-channel derivation

  8. Discriminability of Single and Multichannel Intracortical Microstimulation within Somatosensory Cortex

    Directory of Open Access Journals (Sweden)

    Cynthia Kay Overstreet

    2016-12-01

    Full Text Available The addition of tactile and proprioceptive feedback to neuroprosthetic limbs is expected to significantly improve the control of these devices. Intracortical microstimulation (ICMS of somatosensory cortex is a promising method of delivering this sensory feedback. To date, the main focus of somatosensory ICMS studies has been to deliver discriminable signals, corresponding to varying intensity, to a single location in cortex. However, multiple independent and simultaneous streams of sensory information will need to be encoded by ICMS to provide functionally relevant feedback for a neuroprosthetic limb (e.g. encoding contact events and pressure on multiple digits.In this study, we evaluated the ability of an awake, behaving non-human primate (Macaca mulatta to discriminate ICMS stimuli delivered on multiple electrodes spaced within somatosensory cortex. We delivered serial stimulation on single electrodes to evaluate the discriminability of sensations corresponding to ICMS of distinct cortical locations. Additionally, we delivered trains of multichannel stimulation, derived from a tactile sensor, synchronously across multiple electrodes. Our results indicate that discrimination of multiple ICMS stimuli is a challenging task, but that discriminable sensory percepts can be elicited by both single and multichannel ICMS on electrodes spaced within somatosensory cortex.

  9. Postictal inhibition of the somatosensory cortex

    DEFF Research Database (Denmark)

    Beniczky, Sándor; Jovanovic, Marina; Atkins, Mary Doreen

    2011-01-01

    of the cortical component of the somatosensory evoked potential following stimulation of the left tibial nerve was reduced immediately after the seizure. Our findings suggest that the excitability of the sensory cortex is transiently reduced following a seizure involving the somatosensory area....

  10. Cumulative radiation effect

    International Nuclear Information System (INIS)

    Kirk, J.; Gray, W.M.; Watson, E.R.

    1977-01-01

    In five previous papers, the concept of Cumulative Radiation Effect (CRE) has been presented as a scale of accumulative sub-tolerance radiation damage, with a unique value of the CRE describing a specific level of radiation effect. Simple nomographic and tabular methods for the solution of practical problems in radiotherapy are now described. An essential feature of solving a CRE problem is firstly to present it in a concise and readily appreciated form, and, to do this, nomenclature has been introduced to describe schedules and regimes as compactly as possible. Simple algebraic equations have been derived to describe the CRE achieved by multi-schedule regimes. In these equations, the equivalence conditions existing at the junctions between schedules are not explicit and the equations are based on the CREs of the constituent schedules assessed individually without reference to their context in the regime as a whole. This independent evaluation of CREs for each schedule has resulted in a considerable simplification in the calculation of complex problems. The calculations are further simplified by the use of suitable tables and nomograms, so that the mathematics involved is reduced to simple arithmetical operations which require at the most the use of a slide rule but can be done by hand. The order of procedure in the presentation and calculation of CRE problems can be summarised in an evaluation procedure sheet. The resulting simple methods for solving practical problems of any complexity on the CRE-system are demonstrated by a number of examples. (author)

  11. Observing motor learning produces somatosensory change.

    Science.gov (United States)

    Bernardi, Nicolò F; Darainy, Mohammad; Bricolo, Emanuela; Ostry, David J

    2013-10-01

    Observing the actions of others has been shown to affect motor learning, but does it have effects on sensory systems as well? It has been recently shown that motor learning that involves actual physical practice is also associated with plasticity in the somatosensory system. Here, we assessed the idea that observational learning likewise changes somatosensory function. We evaluated changes in somatosensory function after human subjects watched videos depicting motor learning. Subjects first observed video recordings of reaching movements either in a clockwise or counterclockwise force field. They were then trained in an actual force-field task that involved a counterclockwise load. Measures of somatosensory function were obtained before and after visual observation and also following force-field learning. Consistent with previous reports, video observation promoted motor learning. We also found that somatosensory function was altered following observational learning, both in direction and in magnitude, in a manner similar to that which occurs when motor learning is achieved through actual physical practice. Observation of the same sequence of movements in a randomized order did not result in somatosensory perceptual change. Observational learning and real physical practice appear to tap into the same capacity for sensory change in that subjects that showed a greater change following observational learning showed a reliably smaller change following physical motor learning. We conclude that effects of observing motor learning extend beyond the boundaries of traditional motor circuits, to include somatosensory representations.

  12. Normalization in human somatosensory cortex.

    Science.gov (United States)

    Brouwer, Gijs Joost; Arnedo, Vanessa; Offen, Shani; Heeger, David J; Grant, Arthur C

    2015-11-01

    Functional magnetic resonance imaging (fMRI) was used to measure activity in human somatosensory cortex and to test for cross-digit suppression. Subjects received stimulation (vibration of varying amplitudes) to the right thumb (target) with or without concurrent stimulation of the right middle finger (mask). Subjects were less sensitive to target stimulation (psychophysical detection thresholds were higher) when target and mask digits were stimulated concurrently compared with when the target was stimulated in isolation. fMRI voxels in a region of the left postcentral gyrus each responded when either digit was stimulated. A regression model (called a forward model) was used to separate the fMRI measurements from these voxels into two hypothetical channels, each of which responded selectively to only one of the two digits. For the channel tuned to the target digit, responses in the left postcentral gyrus increased with target stimulus amplitude but were suppressed by concurrent stimulation to the mask digit, evident as a shift in the gain of the response functions. For the channel tuned to the mask digit, a constant baseline response was evoked for all target amplitudes when the mask was absent and responses decreased with increasing target amplitude when the mask was concurrently presented. A computational model based on divisive normalization provided a good fit to the measurements for both mask-absent and target + mask stimulation. We conclude that the normalization model can explain cross-digit suppression in human somatosensory cortex, supporting the hypothesis that normalization is a canonical neural computation. Copyright © 2015 the American Physiological Society.

  13. Somatosensory processing of the tongue in humans

    Directory of Open Access Journals (Sweden)

    Kiwako Sakamoto

    2010-11-01

    Full Text Available We review research on somatosensory (tactile processing of the tongue based on data obtained using non-invasive neurophysiological and neuroimaging methods. Technical difficulties in stimulating the tongue, due to the noise elicited by the stimulator, the fixation of the stimulator, and the vomiting reflex, have necessitated the development of specialized devices. In this article, we show the brain activity relating to somatosensory processing of the tongue evoked by such devices. More recently, the postero-lateral part of the tongue has been stimulated, and the brain response compared with that on stimulation of the antero-lateral part of the tongue. It is likely that a difference existed in somatosensory processing of the tongue, particularly around primary somatosensory cortex (SI, Brodmann area 40 (BA 40, and the anterior cingulate cortex (ACC.

  14. Boosted Regression Trees Outperforms Support Vector Machines in Predicting (Regional) Yields of Winter Wheat from Single and Cumulated Dekadal Spot-VGT Derived Normalized Difference Vegetation Indices

    Science.gov (United States)

    Stas, Michiel; Dong, Qinghan; Heremans, Stien; Zhang, Beier; Van Orshoven, Jos

    2016-08-01

    This paper compares two machine learning techniques to predict regional winter wheat yields. The models, based on Boosted Regression Trees (BRT) and Support Vector Machines (SVM), are constructed of Normalized Difference Vegetation Indices (NDVI) derived from low resolution SPOT VEGETATION satellite imagery. Three types of NDVI-related predictors were used: Single NDVI, Incremental NDVI and Targeted NDVI. BRT and SVM were first used to select features with high relevance for predicting the yield. Although the exact selections differed between the prefectures, certain periods with high influence scores for multiple prefectures could be identified. The same period of high influence stretching from March to June was detected by both machine learning methods. After feature selection, BRT and SVM models were applied to the subset of selected features for actual yield forecasting. Whereas both machine learning methods returned very low prediction errors, BRT seems to slightly but consistently outperform SVM.

  15. Effect of Somatosensory Impairments on Balance Control

    Directory of Open Access Journals (Sweden)

    Alireza Hassanpour

    2012-10-01

    Full Text Available Background and Aim: The somatosensory system is one of the most effective systems in balance control. It consists of peripheral and central components. Knowing the role of these components in balance control assists the developing of effective rehabilitation protocols. In some diseases peripheral components and in others central components are impaired. This paper reviews the effect of impairment of peripheral and central components of the somatosensory system on balance control.Methods: In this study publication about somatosensory impairments from 1983 through 2011 in PubMed, Scopus, ProQuest, Google Scholar, Iran Medex, Iran Doc and Magiran were reviewed. Medical subject headings terms and keywords related to balance, somatosensory, somatosensory loss, and sensory integration/processing were used to perform the searches.Conclusion: Somatosensory impairments either with peripheral or central origin, can cause problems in balance control. However, these problems are not considered in some patients. In these impairments, balance training is recommended to be used alongside other routine treatments in the patients' rehabilitation programs.

  16. Somatosensory deficits after stroke: a scoping review.

    Science.gov (United States)

    Kessner, Simon S; Bingel, Ulrike; Thomalla, Götz

    2016-04-01

    In the past years, there have been increasing research activities focusing on somatosensory symptoms following stroke. However, as compared to the large number of clinical and neuroimaging studies on motor symptoms, the number of studies tracing somatosensory symptoms after stroke and their recovery is rather small. It is an ongoing discussion, to which extent somatosensory deficits after stroke influence patient's long-term outcome in motor and sensory performance and functional independence in activities of daily living. Modern brain imaging techniques allow for studying the impact of stroke lesion localization and size on acute and persisting clinical impairment. Here, we review the literature on somatosensory symptoms after stroke. We summarize epidemiological information on frequency and characteristics of somatosensory symptoms affecting all parts of the body in the acute and chronic stage of stroke. We further give an overview of brain imaging studies of stroke affecting the somatosensory system. Finally, we identify open questions which need to be addressed in future research and summarize the implications for clinical practice.

  17. Barrier function and natural moisturizing factor levels after cumulative exposure to a fruit-derived organic acid and a detergent: different outcomes in atopic and healthy skin and relevance for occupational contact dermatitis in the food industry.

    Science.gov (United States)

    Angelova-Fischer, Irena; Hoek, Anne-Karin; Dapic, Irena; Jakasa, Ivone; Kezic, Sanja; Fischer, Tobias W; Zillikens, Detlef

    2015-12-01

    Fruit-derived organic compounds and detergents are relevant exposure factors for occupational contact dermatitis in the food industry. Although individuals with atopic dermatitis (AD) are at risk for development of occupational contact dermatitis, there have been no controlled studies on the effects of repeated exposure to multiple irritants, relevant for the food industry, in atopic skin. The aim of the study was to investigate the outcomes of repeated exposure to a fruit-derived organic acid and a detergent in AD compared to healthy volunteers. The volunteers were exposed to 2.0% acetic acid (AcA) and/or 0.5% sodium lauryl sulfate (SLS) in controlled tandem repeated irritation test. The outcomes were assessed by measurements of erythema, transepidermal water loss (TEWL) and natural moisturizing factor (NMF) levels. In the AD volunteers, repeated AcA exposure led to barrier disruption and significant TEWL increase; no significant differences after the same exposure in the healthy controls were found. Repeated exposure to SLS and the irritant tandems enhanced the reactions and resulted in a significantly higher increase in TEWL in the AD compared to the control group. Cumulative irritant exposure reduced the NMF levels in both groups. Differences in the severity of irritant-induced barrier impairment in atopic individuals contribute to the risk for occupational contact dermatitis in result of multiple exposures to food-derived irritants and detergents. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Convergence across tactile afferent types in primary and secondary somatosensory cortices.

    Directory of Open Access Journals (Sweden)

    Andrew W Carter

    Full Text Available Integration of information by convergence of inputs onto sensory cortical neurons is a requisite for processing higher-order stimulus features. Convergence across defined peripheral input classes has generally been thought to occur at levels beyond the primary sensory cortex, however recent work has shown that this does not hold for the convergence of slowly-adapting and rapidly-adapting inputs in primary somatosensory cortex. We have used a new analysis method for multi-unit recordings, to show convergence of inputs deriving from the rapidly-adapting and Pacinian channels in a proportion of neurons in both primary and secondary somatosensory cortex in the anaesthetised cat. We have validated this method using single-unit recordings. The secondary somatosensory cortex has a greater proportion of sites that show convergence of this type than primary somatosensory cortex. These findings support the hypothesis that the more complex features processed in higher cortical areas require a greater degree of convergence across input classes, but also shows that this convergence is apparent in the primary somatosensory cortex.

  19. Cumulative Paired φ-Entropy

    Directory of Open Access Journals (Sweden)

    Ingo Klein

    2016-07-01

    Full Text Available A new kind of entropy will be introduced which generalizes both the differential entropy and the cumulative (residual entropy. The generalization is twofold. First, we simultaneously define the entropy for cumulative distribution functions (cdfs and survivor functions (sfs, instead of defining it separately for densities, cdfs, or sfs. Secondly, we consider a general “entropy generating function” φ, the same way Burbea et al. (IEEE Trans. Inf. Theory 1982, 28, 489–495 and Liese et al. (Convex Statistical Distances; Teubner-Verlag, 1987 did in the context of φ-divergences. Combining the ideas of φ-entropy and cumulative entropy leads to the new “cumulative paired φ-entropy” ( C P E φ . This new entropy has already been discussed in at least four scientific disciplines, be it with certain modifications or simplifications. In the fuzzy set theory, for example, cumulative paired φ-entropies were defined for membership functions, whereas in uncertainty and reliability theories some variations of C P E φ were recently considered as measures of information. With a single exception, the discussions in the scientific disciplines appear to be held independently of each other. We consider C P E φ for continuous cdfs and show that C P E φ is rather a measure of dispersion than a measure of information. In the first place, this will be demonstrated by deriving an upper bound which is determined by the standard deviation and by solving the maximum entropy problem under the restriction of a fixed variance. Next, this paper specifically shows that C P E φ satisfies the axioms of a dispersion measure. The corresponding dispersion functional can easily be estimated by an L-estimator, containing all its known asymptotic properties. C P E φ is the basis for several related concepts like mutual φ-information, φ-correlation, and φ-regression, which generalize Gini correlation and Gini regression. In addition, linear rank tests for scale that

  20. Somatosensory profile of patients with haemophilia.

    Science.gov (United States)

    Krüger, S; Boettger, M K; Hilberg, T

    2018-01-01

    Patients with haemophilia (PwH) suffer from an enhanced pain sensitivity due to repetitive joint bleedings. A comprehensive, quantitative examination of the somatosensory system has not been performed in this population to date. Thirty patients with moderate or severe haemophilia A or B and 30 healthy controls were examined by means of Quantitative Sensory Testing to assess the function of the somatosensory system. Detection (DT) and pain thresholds (PT) were determined, amounting to a total of 13 parameters. Both knee joints and the hand as reference were examined in order to assess both joint-specific as well as general changes in the somatosensory profile. Analysing DT and PT, a significant main effect was found for group × stimulus interaction (P ≤ .001). Post hoc tests revealed significant differences in DT between PwH and controls for thermal stimuli across both knees (cold DT: P somatosensory profile in PwH. Our results reveal initial evidence of a combination of peripheral sensitization, indicated by decreased pressure PT and mechanical DT at the knee joints, as well as general changes of the somatosensory system, shown by reduced thermal DT at affected sites and remote from these. Therefore, both mechanisms have to be considered regarding the pain management in PwH. © 2017 John Wiley & Sons Ltd.

  1. The Body Model Theory of Somatosensory Cortex.

    Science.gov (United States)

    Brecht, Michael

    2017-06-07

    I outline a microcircuit theory of somatosensory cortex as a body model serving both for body representation and "body simulation." A modular model of innervated and non-innervated body parts resides in somatosensory cortical layer 4. This body model is continuously updated and compares to an avatar (an animatable puppet) rather than a mere sensory map. Superficial layers provide context and store sensory memories, whereas layer 5 provides motor output and stores motor memories. I predict that layer-6-to-layer-4 inputs initiate body simulations allowing rehearsal and risk assessment of difficult actions, such as jumps. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Somatosensory evoked response: application in neurology

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    Carlos A. M. Guerreiro

    1982-03-01

    Full Text Available One technique used for short-latency somatosensory evoked response (SER is described. SER following nerve stimulation is a unique non-invasive, clinical test used to evaluate the somatosensory pathways. It tests the physiological function of the median nerve, the brachial plexus, the C6-7 cervical roots, cervical spinal cord, the cuneate nuclei, the medial lemniscus, the thalamus, and the contralateral sensory cortex. It has been shown to be a reliable and useful clinical test partiicularly in multiple sclerosis and comatose patients. The promising technique of SER following peroneal nerve stimulation is mentioned.

  3. CUMBIN - CUMULATIVE BINOMIAL PROGRAMS

    Science.gov (United States)

    Bowerman, P. N.

    1994-01-01

    The cumulative binomial program, CUMBIN, is one of a set of three programs which calculate cumulative binomial probability distributions for arbitrary inputs. The three programs, CUMBIN, NEWTONP (NPO-17556), and CROSSER (NPO-17557), can be used independently of one another. CUMBIN can be used by statisticians and users of statistical procedures, test planners, designers, and numerical analysts. The program has been used for reliability/availability calculations. CUMBIN calculates the probability that a system of n components has at least k operating if the probability that any one operating is p and the components are independent. Equivalently, this is the reliability of a k-out-of-n system having independent components with common reliability p. CUMBIN can evaluate the incomplete beta distribution for two positive integer arguments. CUMBIN can also evaluate the cumulative F distribution and the negative binomial distribution, and can determine the sample size in a test design. CUMBIN is designed to work well with all integer values 0 < k <= n. To run the program, the user simply runs the executable version and inputs the information requested by the program. The program is not designed to weed out incorrect inputs, so the user must take care to make sure the inputs are correct. Once all input has been entered, the program calculates and lists the result. The CUMBIN program is written in C. It was developed on an IBM AT with a numeric co-processor using Microsoft C 5.0. Because the source code is written using standard C structures and functions, it should compile correctly with most C compilers. The program format is interactive. It has been implemented under DOS 3.2 and has a memory requirement of 26K. CUMBIN was developed in 1988.

  4. Somatosensory Neurotoxicity: Agents and Assessment Methodology**

    Science.gov (United States)

    The somatosensory system is comprised of a variety of sensory receptors located in the skin, muscle tendons, and visceral organs that are innervated by myelinated and nonmyelinated axons of the peripheral nervous system. These peripheral sensory nerve fibers in tum communicate so...

  5. Somatosensory Neurotoxicity: Agents and Assessment Methodology

    Science.gov (United States)

    The somatosensory system is comprised of a variety of sensory receptors located in the skin, muscle tendons, and visceral organs that are innervated by myelinated and nonmyelinated axons of the peripheral nervous system. These peripheral sensory nerve fibers in turn communicate s...

  6. Somatosensory evoked potentials in children with autism

    African Journals Online (AJOL)

    Hanan Galal Azouz

    2013-09-07

    Sep 7, 2013 ... by the brain. Rates of sensory processing dysfunction may be as high as 90% in individuals with Autism Spectrum Dis- order.9–12. Somatosensory perception plays a central role in the early stages of human ..... dance with previous studies of SSEP on autistic children.18,23. Regarding the peak latency of ...

  7. Somatosensory evoked potentials in children with autism

    Directory of Open Access Journals (Sweden)

    Hanan Galal Azouz

    2014-06-01

    Conclusions: Children with autism have abnormal SSEP changes and were significantly related to the presence of sensory abnormalities, indicating central cortical dysfunction of somatosensory area. On the other hand, these abnormal SSEP changes were not related to the severity of autism.

  8. Somatosensory Neurotoxicity: Agents and Assessment Methodology.

    Science.gov (United States)

    The somatosensory system is comprised of a variety of sensory receptors located in the skin, muscle tendons, and visceral organs that are innervated by myelinated and nonmyelinated axons of the peripheral nervous system. These peripheral sensory nerve fibers in tum communicate so...

  9. Somatosensory evoked potentials in children with autism

    OpenAIRE

    Hanan Galal Azouz; Mona Khalil; Hayam Moustafa Abd El Ghani; Hatim Mohamed Hamed

    2014-01-01

    Introduction: Autism is a neurodevelopmental disorder in the category of pervasive developmental disorders (PDD), which is characterized by widespread abnormalities of social interactions, communication, and severely restricted interests and highly repetitive behavior. Children with autism show sensory and perceptual abnormalities. They have either hyposensitivity or hypersensitivity to sensory, auditory, and visual stimuli. Objectives: The aim of this work was to study somatosensory evoke...

  10. CROSSER - CUMULATIVE BINOMIAL PROGRAMS

    Science.gov (United States)

    Bowerman, P. N.

    1994-01-01

    The cumulative binomial program, CROSSER, is one of a set of three programs which calculate cumulative binomial probability distributions for arbitrary inputs. The three programs, CROSSER, CUMBIN (NPO-17555), and NEWTONP (NPO-17556), can be used independently of one another. CROSSER can be used by statisticians and users of statistical procedures, test planners, designers, and numerical analysts. The program has been used for reliability/availability calculations. CROSSER calculates the point at which the reliability of a k-out-of-n system equals the common reliability of the n components. It is designed to work well with all integer values 0 < k <= n. To run the program, the user simply runs the executable version and inputs the information requested by the program. The program is not designed to weed out incorrect inputs, so the user must take care to make sure the inputs are correct. Once all input has been entered, the program calculates and lists the result. It also lists the number of iterations of Newton's method required to calculate the answer within the given error. The CROSSER program is written in C. It was developed on an IBM AT with a numeric co-processor using Microsoft C 5.0. Because the source code is written using standard C structures and functions, it should compile correctly with most C compilers. The program format is interactive. It has been implemented under DOS 3.2 and has a memory requirement of 26K. CROSSER was developed in 1988.

  11. A Framework for Treating Cumulative Trauma with Art Therapy

    Science.gov (United States)

    Naff, Kristina

    2014-01-01

    Cumulative trauma is relatively undocumented in art therapy practice, although there is growing evidence that art therapy provides distinct benefits for resolving various traumas. This qualitative study proposes an art therapy treatment framework for cumulative trauma derived from semi-structured interviews with three art therapists and artistic…

  12. Cumulative environmental effects. Summary

    International Nuclear Information System (INIS)

    2012-01-01

    This report presents a compilation of knowledge about the state of the environment and human activity in the Norwegian part of the North Sea and Skagerrak. The report gives an overview of pressures and impacts on the environment from normal activity and in the event of accidents. This is used to assess the cumulative environmental effects, which factors have most impact and where the impacts are greatest, and to indicate which problems are expected to be most serious in the future. The report is intended to provide relevant information that can be used in the management of the marine area in the future. It also provides input for the identification of environmental targets and management measures for the North Sea and Skagerrak.(Author)

  13. Cumulative environmental effects. Summary

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    This report presents a compilation of knowledge about the state of the environment and human activity in the Norwegian part of the North Sea and Skagerrak. The report gives an overview of pressures and impacts on the environment from normal activity and in the event of accidents. This is used to assess the cumulative environmental effects, which factors have most impact and where the impacts are greatest, and to indicate which problems are expected to be most serious in the future. The report is intended to provide relevant information that can be used in the management of the marine area in the future. It also provides input for the identification of environmental targets and management measures for the North Sea and Skagerrak.(Author)

  14. NEWTONP - CUMULATIVE BINOMIAL PROGRAMS

    Science.gov (United States)

    Bowerman, P. N.

    1994-01-01

    The cumulative binomial program, NEWTONP, is one of a set of three programs which calculate cumulative binomial probability distributions for arbitrary inputs. The three programs, NEWTONP, CUMBIN (NPO-17555), and CROSSER (NPO-17557), can be used independently of one another. NEWTONP can be used by statisticians and users of statistical procedures, test planners, designers, and numerical analysts. The program has been used for reliability/availability calculations. NEWTONP calculates the probably p required to yield a given system reliability V for a k-out-of-n system. It can also be used to determine the Clopper-Pearson confidence limits (either one-sided or two-sided) for the parameter p of a Bernoulli distribution. NEWTONP can determine Bayesian probability limits for a proportion (if the beta prior has positive integer parameters). It can determine the percentiles of incomplete beta distributions with positive integer parameters. It can also determine the percentiles of F distributions and the midian plotting positions in probability plotting. NEWTONP is designed to work well with all integer values 0 < k <= n. To run the program, the user simply runs the executable version and inputs the information requested by the program. NEWTONP is not designed to weed out incorrect inputs, so the user must take care to make sure the inputs are correct. Once all input has been entered, the program calculates and lists the result. It also lists the number of iterations of Newton's method required to calculate the answer within the given error. The NEWTONP program is written in C. It was developed on an IBM AT with a numeric co-processor using Microsoft C 5.0. Because the source code is written using standard C structures and functions, it should compile correctly with most C compilers. The program format is interactive. It has been implemented under DOS 3.2 and has a memory requirement of 26K. NEWTONP was developed in 1988.

  15. Temporal factors affecting somatosensory-auditory interactions in speech processing

    Directory of Open Access Journals (Sweden)

    Takayuki eIto

    2014-11-01

    Full Text Available Speech perception is known to rely on both auditory and visual information. However, sound specific somatosensory input has been shown also to influence speech perceptual processing (Ito et al., 2009. In the present study we addressed further the relationship between somatosensory information and speech perceptual processing by addressing the hypothesis that the temporal relationship between orofacial movement and sound processing contributes to somatosensory-auditory interaction in speech perception. We examined the changes in event-related potentials in response to multisensory synchronous (simultaneous and asynchronous (90 ms lag and lead somatosensory and auditory stimulation compared to individual unisensory auditory and somatosensory stimulation alone. We used a robotic device to apply facial skin somatosensory deformations that were similar in timing and duration to those experienced in speech production. Following synchronous multisensory stimulation the amplitude of the event-related potential was reliably different from the two unisensory potentials. More importantly, the magnitude of the event-related potential difference varied as a function of the relative timing of the somatosensory-auditory stimulation. Event-related activity change due to stimulus timing was seen between 160-220 ms following somatosensory onset, mostly around the parietal area. The results demonstrate a dynamic modulation of somatosensory-auditory convergence and suggest the contribution of somatosensory information for speech processing process is dependent on the specific temporal order of sensory inputs in speech production.

  16. [Maturation of cerebral somatosensory evoked potentials].

    Science.gov (United States)

    Cadilhac, J; Zhu, Y; Georgesco, M; Echenne, B; Rodiere, M

    1985-07-01

    Cerebral somatosensory evoked potentials (SEPs) were elicited by stimulation of the median nerve and/or posterior tibial nerve in 117 children of 1 day to 16 years old. A major negative wave (N) was consistently recorded from the parietal region of the scalp when the arm was stimulated. The peak latency, the onset latency, the rising time and the duration of H wave are closely correlated with age and body length. The latencies are shortest in the subjects of 1-3 years old. SEPs to lower extremity stimulation were inconstant in the infants before the age of one. The major positive wave (P) has a variable topographic distribution along the middle line, over the scalp. The latencies are also very variable in the different subjects of the same age as well as in the same subject with different locations of active electrode. Among the parameters studied as for N wave, only the rising time of P wave is significantly correlated with age. The latencies of P wave have the shortest value in the subjects of 1-3 years old. The comparison of SEPs to upper and to lower limb stimulations shows that there is no relationship between them in respect to their morphology and amplitude. The minimum value of the latencies of N and P waves was observed at the same age but the difference between the peak latencies of P and N waves in the same subject increases considerably after 2 years of age and reaches the adult value after 5 years of age. These resultats indicate that the maturation of the peripheral somatosensory pathways proceeds at a higher rate than that of the central somatosensory pathways, that the maturation of the somatosensory pathways of the upper limb precedes that of the lower limb, and that the rising time of N or P waves is a good index of cortical maturation. The clinical utility of these SEPs in pediatrics is discussed.

  17. Somatosensory and acoustic brain stem reflex myoclonus.

    OpenAIRE

    Shibasaki, H; Kakigi, R; Oda, K; Masukawa, S

    1988-01-01

    A patient with brain stem reflex myoclonus due to a massive midbrain infarct was studied electrophysiologically. Myoclonic jerks were elicited at variable latencies by tapping anywhere on the body or by acoustic stimuli, and mainly involved flexor muscles of upper extremities. The existence of convergence of somatosensory and acoustic inputs in the brain stem was suggested. This myoclonus seemed to be mediated by a mechanism similar to the spino-bulbo-spinal reflex.

  18. Tinnitus: Maladaptive auditory-somatosensory plasticity.

    Science.gov (United States)

    Wu, Calvin; Stefanescu, Roxana A; Martel, David T; Shore, Susan E

    2016-04-01

    Tinnitus, the phantom perception of sound, is physiologically characterized by an increase in spontaneous neural activity in the central auditory system. However, as tinnitus is often associated with hearing impairment, it is unclear how a decrease of afferent drive can result in central hyperactivity. In this review, we first assess methods for tinnitus induction and objective measures of the tinnitus percept in animal models. From animal studies, we discuss evidence that tinnitus originates in the cochlear nucleus (CN), and hypothesize mechanisms whereby hyperactivity may develop in the CN after peripheral auditory nerve damage. We elaborate how this process is likely mediated by plasticity of auditory-somatosensory integration in the CN: the circuitry in normal circumstances maintains a balance of auditory and somatosensory activities, and loss of auditory inputs alters the balance of auditory somatosensory integration in a stimulus timing dependent manner, which propels the circuit towards hyperactivity. Understanding the mechanisms underlying tinnitus generation is essential for its prevention and treatment. This article is part of a Special Issue entitled . Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Somatosensory tinnitus: Current evidence and future perspectives.

    Science.gov (United States)

    Ralli, Massimo; Greco, Antonio; Turchetta, Rosaria; Altissimi, Giancarlo; de Vincentiis, Marco; Cianfrone, Giancarlo

    2017-06-01

    In some individuals, tinnitus can be modulated by specific maneuvers of the temporomandibular joint, head and neck, eyes, and limbs. Neuroplasticity seems to play a central role in this capacity for modulation, suggesting that abnormal interactions between the sensory modalities, sensorimotor systems, and neurocognitive and neuroemotional networks may contribute to the development of somatosensory tinnitus. Current evidence supports a link between somatic disorders and higher modulation of tinnitus, especially in patients with a normal hearing threshold. Patients with tinnitus who have somatic disorders seems to have a higher chance of modulating their tinnitus with somatic maneuvers; consistent improvements in tinnitus symptoms have been observed in patients with temporomandibular joint disease following targeted therapy for temporomandibular disorders. Somatosensory tinnitus is often overlooked by otolaryngologists and not fully investigated during the diagnostic process. Somatic disorders, when identified and treated, can be a valid therapeutic target for tinnitus; however, somatic screening of subjects for somatosensory tinnitus is imperative for correct selection of patients who would benefit from a multidisciplinary somatic approach.

  20. Mnemonic neuronal activity in somatosensory cortex.

    Science.gov (United States)

    Zhou, Y D; Fuster, J M

    1996-09-17

    Single-unit activity was recorded from the hand areas of the somatosensory cortex of monkeys trained to perform a haptic delayed matching to sample task with objects of identical dimensions but different surface features. During the memory retention period of the task (delay), many units showed sustained firing frequency change, either excitation or inhibition. In some cases, firing during that period was significantly higher after one sample object than after another. These observations indicate the participation of somatosensory neurons not only in the perception but in the short-term memory of tactile stimuli. Neurons most directly implicated in tactile memory are (i) those with object-selective delay activity, (ii) those with nondifferential delay activity but without activity related to preparation for movement, and (iii) those with delay activity in the haptic-haptic delayed matching task but no such activity in a control visuo-haptic delayed matching task. The results indicate that cells in early stages of cortical somatosensory processing participate in haptic short-term memory.

  1. Somatosensory processes subserving perception and action.

    Science.gov (United States)

    Dijkerman, H Chris; de Haan, Edward H F

    2007-04-01

    The functions of the somatosensory system are multiple. We use tactile input to localize and experience the various qualities of touch, and proprioceptive information to determine the position of different parts of the body with respect to each other, which provides fundamental information for action. Further, tactile exploration of the characteristics of external objects can result in conscious perceptual experience and stimulus or object recognition. Neuroanatomical studies suggest parallel processing as well as serial processing within the cerebral somatosensory system that reflect these separate functions, with one processing stream terminating in the posterior parietal cortex (PPC), and the other terminating in the insula. We suggest that, analogously to the organisation of the visual system, somatosensory processing for the guidance of action can be dissociated from the processing that leads to perception and memory. In addition, we find a second division between tactile information processing about external targets in service of object recognition and tactile information processing related to the body itself. We suggest the posterior parietal cortex subserves both perception and action, whereas the insula principally subserves perceptual recognition and learning.

  2. Magnetoencephalographic Imaging of Auditory and Somatosensory Cortical Responses in Children with Autism and Sensory Processing Dysfunction.

    Science.gov (United States)

    Demopoulos, Carly; Yu, Nina; Tripp, Jennifer; Mota, Nayara; Brandes-Aitken, Anne N; Desai, Shivani S; Hill, Susanna S; Antovich, Ashley D; Harris, Julia; Honma, Susanne; Mizuiri, Danielle; Nagarajan, Srikantan S; Marco, Elysa J

    2017-01-01

    This study compared magnetoencephalographic (MEG) imaging-derived indices of auditory and somatosensory cortical processing in children aged 8-12 years with autism spectrum disorder (ASD; N = 18), those with sensory processing dysfunction (SPD; N = 13) who do not meet ASD criteria, and typically developing control (TDC; N = 19) participants. The magnitude of responses to both auditory and tactile stimulation was comparable across all three groups; however, the M200 latency response from the left auditory cortex was significantly delayed in the ASD group relative to both the TDC and SPD groups, whereas the somatosensory response of the ASD group was only delayed relative to TDC participants. The SPD group did not significantly differ from either group in terms of somatosensory latency, suggesting that participants with SPD may have an intermediate phenotype between ASD and TDC with regard to somatosensory processing. For the ASD group, correlation analyses indicated that the left M200 latency delay was significantly associated with performance on the WISC-IV Verbal Comprehension Index as well as the DSTP Acoustic-Linguistic index. Further, these cortical auditory response delays were not associated with somatosensory cortical response delays or cognitive processing speed in the ASD group, suggesting that auditory delays in ASD are domain specific rather than associated with generalized processing delays. The specificity of these auditory delays to the ASD group, in addition to their correlation with verbal abilities, suggests that auditory sensory dysfunction may be implicated in communication symptoms in ASD, motivating further research aimed at understanding the impact of sensory dysfunction on the developing brain.

  3. Magnetoencephalographic Imaging of Auditory and Somatosensory Cortical Responses in Children with Autism and Sensory Processing Dysfunction

    Directory of Open Access Journals (Sweden)

    Carly Demopoulos

    2017-05-01

    Full Text Available This study compared magnetoencephalographic (MEG imaging-derived indices of auditory and somatosensory cortical processing in children aged 8–12 years with autism spectrum disorder (ASD; N = 18, those with sensory processing dysfunction (SPD; N = 13 who do not meet ASD criteria, and typically developing control (TDC; N = 19 participants. The magnitude of responses to both auditory and tactile stimulation was comparable across all three groups; however, the M200 latency response from the left auditory cortex was significantly delayed in the ASD group relative to both the TDC and SPD groups, whereas the somatosensory response of the ASD group was only delayed relative to TDC participants. The SPD group did not significantly differ from either group in terms of somatosensory latency, suggesting that participants with SPD may have an intermediate phenotype between ASD and TDC with regard to somatosensory processing. For the ASD group, correlation analyses indicated that the left M200 latency delay was significantly associated with performance on the WISC-IV Verbal Comprehension Index as well as the DSTP Acoustic-Linguistic index. Further, these cortical auditory response delays were not associated with somatosensory cortical response delays or cognitive processing speed in the ASD group, suggesting that auditory delays in ASD are domain specific rather than associated with generalized processing delays. The specificity of these auditory delays to the ASD group, in addition to their correlation with verbal abilities, suggests that auditory sensory dysfunction may be implicated in communication symptoms in ASD, motivating further research aimed at understanding the impact of sensory dysfunction on the developing brain.

  4. Cumulative radiation effect

    International Nuclear Information System (INIS)

    Kirk, J.; Cain, O.; Gray, W.M.

    1977-01-01

    Cumulative Radiation Effect (CRE) represents a scale of accumulative sub-tolerance radiation damage, with a unique value of the CRE describing a specific level of radiation effect. Computer calculations have been used to simplify the evaluation of problems associated with the applications of the CRE-system in radiotherapy. In a general appraisal of the applications of computers to the CRE-system, the various problems encountered in clinical radiotherapy have been categorised into those involving the evaluation of a CRE at a point in tissue and those involving the calculation of CRE distributions. As a general guide, the computer techniques adopted at the Glasgow Institute of Radiotherapeutics for the solution of CRE problems are presented, and consist basically of a package of three interactive programs for point CRE calculations and a Fortran program which calculates CRE distributions for iso-effect treatment planning. Many examples are given to demonstrate the applications of these programs, and special emphasis has been laid on the problem of treating a point in tissue with different doses per fraction on alternate treatment days. The wide range of possible clinical applications of the CRE-system has been outlined and described under the categories of routine clinical applications, retrospective and prospective surveys of patient treatment, and experimental and theoretical research. Some of these applications such as the results of surveys and studies of time optimisation of treatment schedules could have far-reaching consequences and lead to significant improvements in treatment and cure rates with the minimum damage to normal tissue. (author)

  5. Epidural motor cortex stimulation suppresses somatosensory evoked potentials in the primary somatosensory cortex of the rat.

    Science.gov (United States)

    Chiou, Ruei-Jen; Lee, Hsiao-Yun; Chang, Chen-Wei; Lin, Kuan-Hung; Kuo, Chung-Chih

    2012-06-29

    Motor cortex stimulation (MCS) is a promising clinical procedure to help alleviate chronic pain. Animal models demonstrated that MCS is effective in lessening nocifensive behaviors. The present study explored the effects of MCS on cortical somatosensory evoked potentials (SEPs) recorded at the primary somatosensory cortex (SI) of the rat. SEPs were evoked by electrical stimulation applied to the contralateral forepaws. Effects of different intensities, frequencies, and durations of MCS were tested. MCS at ≥2V suppressed SEPs of the ipsilateral SI. Suppression lasted 120 min at an intensity of 5 V. The optimal frequency was 50 Hz, and the duration was 30s. In contrast, MCS did not affect SEPs recorded on the contralateral SI. Cortical stimulation out of the motor cortex did not induce a decrease in the ipsilateral SEPs. We also investigated involvement of the endogenous opioid system in this inhibition of SEPs induced by MCS. The opioid antagonist, naloxone (0.5 mg/kg), was administered 30 min before MCS. Application of naloxone completely prevented the inhibitory effect of MCS on ipsilateral SEPs. These results demonstrate that MCS blocked the transmission of somatosensory information to the primary somatosensory cortex, and this interference was mediated by the endogenous opioid system. This inhibitory effect on sensory transmission induced by MCS may reflect its antinociceptive effect. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Somatosensory evoked potentials in children with autism | Azouz ...

    African Journals Online (AJOL)

    They have either hyposensitivity or hypersensitivity to sensory, auditory, and visual stimuli. Objectives: The aimof thisworkwas to study somatosensory evoked potential (SSEPs) changesamong children with autism, and their relation to somatosensory manifestations and severity of autism. Subjects: Thirty children with ...

  7. Behavioral demonstration of a somatosensory neuroprosthesis.

    Science.gov (United States)

    Berg, J A; Dammann, J F; Tenore, F V; Tabot, G A; Boback, J L; Manfredi, L R; Peterson, M L; Katyal, K D; Johannes, M S; Makhlin, A; Wilcox, R; Franklin, R K; Vogelstein, R J; Hatsopoulos, N G; Bensmaia, S J

    2013-05-01

    Tactile sensation is critical for effective object manipulation, but current prosthetic upper limbs make no provision for delivering somesthetic feedback to the user. For individuals who require use of prosthetic limbs, this lack of feedback transforms a mundane task into one that requires extreme concentration and effort. Although vibrotactile motors and sensory substitution devices can be used to convey gross sensations, a direct neural interface is required to provide detailed and intuitive sensory feedback. In light of this, we describe the implementation of a somatosensory prosthesis with which we elicit, through intracortical microstimulation (ICMS), percepts whose magnitude is graded according to the force exerted on the prosthetic finger. Specifically, the prosthesis consists of a sensorized finger, the force output of which is converted into a regime of ICMS delivered to primary somatosensory cortex through chronically implanted multi-electrode arrays. We show that the performance of animals (Rhesus macaques) on a tactile task is equivalent whether stimuli are delivered to the native finger or to the prosthetic finger.

  8. Early determination of somatosensory cortex in the human brain.

    Science.gov (United States)

    Juenger, Hendrik; de Haan, Bianca; Krägeloh-Mann, Ingeborg; Staudt, Martin; Karnath, Hans-Otto

    2011-08-01

    The developing brain possesses a high potential for neuroplasticity. Yet, this remarkable potential of (re-)organization is not a general principle. It seems to vary among different functional systems. Here, we show that distinct brain structures involved in somatosensory processing are already prenatally determined so that a pre- or perinatally acquired (congenital) brain damage of such structures results in a persistent somatosensory deficit. Eleven patients with hemiparesis due to congenital cortico-subcortical unilateral stroke who showed versus not showed a somatosensory deficit were contrasted with magnetic resonance imaging lesion-behavior mapping. The brain areas which were typically damaged in patients with a somatosensory deficit but typically spared in patients without a somatosensory deficit were located in the primary and secondary somatosensory cortex (S1, S2) as well as the inferior parietal cortex directly neighboring S1 and S2. The results argue for an early functional determination of primary and secondary somatosensory cortex, without substantial capacities for (re-)organization. They demonstrate that cortical damage of these areas cannot be compensated by shifting the functional representation to undamaged parts of the cortex.

  9. Vestibular-somatosensory interactions: effects of passive whole-body rotation on somatosensory detection.

    Directory of Open Access Journals (Sweden)

    Elisa Raffaella Ferrè

    Full Text Available Vestibular signals are strongly integrated with information from several other sensory modalities. For example, vestibular stimulation was reported to improve tactile detection. However, this improvement could reflect either a multimodal interaction or an indirect interaction driven by vestibular effects on spatial attention and orienting. Here we investigate whether natural vestibular activation induced by passive whole-body rotation influences tactile detection. In particular, we assessed the ability to detect faint tactile stimuli to the fingertips of the left and right hand during spatially congruent or incongruent rotations. We found that passive whole-body rotations significantly enhanced sensitivity to faint shocks, without affecting response bias. Critically, this enhancement of somatosensory sensitivity did not depend on the spatial congruency between the direction of rotation and the hand stimulated. Thus, our results support a multimodal interaction, likely in brain areas receiving both vestibular and somatosensory signals.

  10. Consolidation of human somatosensory memory during motor learning.

    Science.gov (United States)

    Cuppone, Anna Vera; Semprini, Marianna; Konczak, Jürgen

    2018-03-13

    Sensorimotor learning is a bidirectional process associated with concurrent neuroplastic changes in the motor and somatosensory system. While motor memory consolidation and retention have been extensively studied during skill acquisition, little is known about the formation and consolidation of somatosensory memory associated with motor learning. Using a robotic exoskeleton, we tracked markers of somatosensory and motor learning while healthy participants trained to make goal-directed wrist reaching movements over five days and evaluated retention for up to 10 days after practice. Markers of somatosensory learning were changes in wrist position sense bias (systematic error) and precision (random error). The main results are as follows: First, somatosensory (proprioceptive) memory consolidation shows signs of cost savings with repeated sensorimotor training - the same feature is known for motor memory formation. Moreover, somatosensory learning generalized to untrained workspace. Second, somatosensory learning over days can be characterized as an early improvement in sensory precision and a later improvement in sensory bias. Third, the time course of learning gains in position sense acuity coincided with improvements in spatial movement accuracy. Finally, the gains of somatosensory learning were retained for several days. Improvements in position sense bias were still visible up to 3 days after the end of practice for the trained workspace positions, but decayed faster in the untrained workspace. Improvements in position sense precision were retained for up to 10 days and were workspace independent. The findings are consistent with the view that an internal model of somatosensory joint space is formed during motor learning. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Clinical application of somatosensory amplification in psychosomatic medicine

    Directory of Open Access Journals (Sweden)

    Nakao Mutsuhiro

    2007-10-01

    Full Text Available Abstract Many patients with somatoform disorders are frequently encountered in psychosomatic clinics as well as in primary care clinics. To assess such patients objectively, the concept of somatosensory amplification may be useful. Somatosensory amplification refers to the tendency to experience a somatic sensation as intense, noxious, and disturbing. It may have a role in a variety of medical conditions characterized by somatic symptoms that are disproportionate to demonstrable organ pathology. It may also explain some of the variability in somatic symptomatology found among different patients with the same serious medical disorder. It has been assessed with a self-report questionnaire, the Somatosensory Amplification Scale. This instrument was developed in a clinical setting in the U.S., and the reliability and validity of the Japanese and Turkish versions have been confirmed as well. Many studies have attempted to clarify the specific role of somatosensory amplification as a pathogenic mechanism in somatization. It has been reported that somatosensory amplification does not correlate with heightened sensitivity to bodily sensations and that emotional reactivity exerts its influence on somatization via a negatively biased reporting style. According to our recent electroencephalographic study, somatosensory amplification appears to reflect some aspects of long-latency cognitive processing rather than short-latency interoceptive sensitivity. The concept of somatosensory amplification can be useful as an indicator of somatization in the therapy of a broad range of disorders, from impaired self-awareness to various psychiatric disorders. It also provides useful information for choosing appropriate pharmacological or psychological therapy. While somatosensory amplification has a role in the presentation of somatic symptoms, it is closely associated with other factors, namely, anxiety, depression, and alexithymia that may also influence the same

  12. Clinical application of somatosensory amplification in psychosomatic medicine

    Science.gov (United States)

    Nakao, Mutsuhiro; Barsky, Arthur J

    2007-01-01

    Many patients with somatoform disorders are frequently encountered in psychosomatic clinics as well as in primary care clinics. To assess such patients objectively, the concept of somatosensory amplification may be useful. Somatosensory amplification refers to the tendency to experience a somatic sensation as intense, noxious, and disturbing. It may have a role in a variety of medical conditions characterized by somatic symptoms that are disproportionate to demonstrable organ pathology. It may also explain some of the variability in somatic symptomatology found among different patients with the same serious medical disorder. It has been assessed with a self-report questionnaire, the Somatosensory Amplification Scale. This instrument was developed in a clinical setting in the U.S., and the reliability and validity of the Japanese and Turkish versions have been confirmed as well. Many studies have attempted to clarify the specific role of somatosensory amplification as a pathogenic mechanism in somatization. It has been reported that somatosensory amplification does not correlate with heightened sensitivity to bodily sensations and that emotional reactivity exerts its influence on somatization via a negatively biased reporting style. According to our recent electroencephalographic study, somatosensory amplification appears to reflect some aspects of long-latency cognitive processing rather than short-latency interoceptive sensitivity. The concept of somatosensory amplification can be useful as an indicator of somatization in the therapy of a broad range of disorders, from impaired self-awareness to various psychiatric disorders. It also provides useful information for choosing appropriate pharmacological or psychological therapy. While somatosensory amplification has a role in the presentation of somatic symptoms, it is closely associated with other factors, namely, anxiety, depression, and alexithymia that may also influence the same. The specific role of

  13. Risk factors affecting somatosensory function after sagittal split osteotomy

    DEFF Research Database (Denmark)

    Thygesen, Torben Henrik; Jensen, Allan Bardow; Helleberg, M

    2008-01-01

    Purpose The aim of this study was to evaluate potential individual and intraoperative risk factors associated with bilateral sagittal split osteotomy (BSSO) and to correlate the findings with postoperative changes in somatosensory function. Patients and Methods A total of 18 men and 29 women (mean...... correlations were noted between preoperative values for somatosensory function and changes in these variables after BSSO. Patients with low sensory thresholds before BSSO experienced more impairment than those patients with higher preoperative sensory thresholds. Conclusion These findings imply...... that somatosensory function after BSSO is dependent on both intraoperative risk factors and preoperative sensation levels....

  14. Primary somatosensory cortex hand representation dynamically modulated by motor output.

    Science.gov (United States)

    McGeoch, Paul D; Brang, David; Huang, Mingxiong; Ramachandran, V S

    2015-02-01

    The brain's primary motor and primary somatosensory cortices are generally viewed as functionally distinct entities. Here we show by means of magnetoencephalography with a phantom-limb patient, that movement of the phantom hand leads to a change in the response of the primary somatosensory cortex to tactile stimulation. This change correlates with the described conscious perception and suggests a greater degree of functional unification between the primary motor and somatosensory cortices than is currently realized. We suggest that this may reflect the evolution of this part of the human brain, which is thought to have occurred from an undifferentiated sensorimotor cortex.

  15. Making sense out of spinal cord somatosensory development

    Science.gov (United States)

    Seal, Rebecca P.

    2016-01-01

    The spinal cord integrates and relays somatosensory input, leading to complex motor responses. Research over the past couple of decades has identified transcription factor networks that function during development to define and instruct the generation of diverse neuronal populations within the spinal cord. A number of studies have now started to connect these developmentally defined populations with their roles in somatosensory circuits. Here, we review our current understanding of how neuronal diversity in the dorsal spinal cord is generated and we discuss the logic underlying how these neurons form the basis of somatosensory circuits. PMID:27702783

  16. [The effect of cigarettes on somatosensory potentials].

    Science.gov (United States)

    León, F E; Suwazono, S; Arimura, K; Osame, M

    1998-01-01

    The physiological and pathological effects of cigarettes on the nervous system have been widely studied, but none of the investigations carried out has enabled us to determine the degree to which nicotine may affect the central pathways of somatosensorial evoked potentials in humans. Following parameters established internationally for investigation of the effects of nicotine on the nervous system, we find that the N18 wave obtained by stimulation of the median nerve before smoking completely disappears after smoking for 3 minutes and reappears 10 minutes after smoking has stopped. Therefore, we conclude that the action of nicotine on these evoked potentials is mainly subcortical, and for this reason it is essential to investigate the toxicological history before carrying out any clinical or neurophysiological study, since this might affect the results obtained.

  17. Somatosensory Substrates of Flight Control in Bats

    Directory of Open Access Journals (Sweden)

    Kara L. Marshall

    2015-05-01

    Full Text Available Flight maneuvers require rapid sensory integration to generate adaptive motor output. Bats achieve remarkable agility with modified forelimbs that serve as airfoils while retaining capacity for object manipulation. Wing sensory inputs provide behaviorally relevant information to guide flight; however, components of wing sensory-motor circuits have not been analyzed. Here, we elucidate the organization of wing innervation in an insectivore, the big brown bat, Eptesicus fuscus. We demonstrate that wing sensory innervation differs from other vertebrate forelimbs, revealing a peripheral basis for the atypical topographic organization reported for bat somatosensory nuclei. Furthermore, the wing is innervated by an unusual complement of sensory neurons poised to report airflow and touch. Finally, we report that cortical neurons encode tactile and airflow inputs with sparse activity patterns. Together, our findings identify neural substrates of somatosensation in the bat wing and imply that evolutionary pressures giving rise to mammalian flight led to unusual sensorimotor projections.

  18. Mechanosensor Channels in Mammalian Somatosensory Neurons

    Directory of Open Access Journals (Sweden)

    Patrick Delmas

    2007-09-01

    Full Text Available Mechanoreceptive sensory neurons innervating the skin, skeletal muscles andviscera signal both innocuous and noxious information necessary for proprioception, touchand pain. These neurons are responsible for the transduction of mechanical stimuli intoaction potentials that propagate to the central nervous system. The ability of these cells todetect mechanical stimuli impinging on them relies on the presence of mechanosensitivechannels that transduce the external mechanical forces into electrical and chemical signals.Although a great deal of information regarding the molecular and biophysical properties ofmechanosensitive channels in prokaryotes has been accumulated over the past two decades,less is known about the mechanosensitive channels necessary for proprioception and thesenses of touch and pain. This review summarizes the most pertinent data onmechanosensitive channels of mammalian somatosensory neurons, focusing on theirproperties, pharmacology and putative identity.

  19. Somatosensory discrimination deficits following pediatric cerebral malaria.

    Science.gov (United States)

    Dugbartey, A T; Spellacy, F J; Dugbartey, M T

    1998-09-01

    Pathologic studies of central nervous system damage in human falciparum malaria indicate primary localization in the cerebral white matter. We report a sensory-perceptual investigation of 20 Ghanaian children with a recent history of cerebral malaria who were age-, gender-, and education-matched with 20 healthy control subjects. Somatosensory examinations failed to show any evidence of hemianesthesia, pseudohemianesthesia, or extinction to double simultaneous tactile stimulation. While unilateral upper limb testing revealed intact unimanual tactile roughness discrimination, bimanual tactile discrimination, however, was significantly impaired in the cerebral malaria group. A strong negative correlation (r = -0.72) between coma duration and the bimanual tactile roughness discrimination test was also found. An inefficiency in the integrity of callosal fibers appear to account for our findings, although alternative subcortical mechanisms known to be involved in information transfer across the cerebral hemispheres may be compromised as well.

  20. Wick polynomials and time-evolution of cumulants

    Science.gov (United States)

    Lukkarinen, Jani; Marcozzi, Matteo

    2016-08-01

    We show how Wick polynomials of random variables can be defined combinatorially as the unique choice, which removes all "internal contractions" from the related cumulant expansions, also in a non-Gaussian case. We discuss how an expansion in terms of the Wick polynomials can be used for derivation of a hierarchy of equations for the time-evolution of cumulants. These methods are then applied to simplify the formal derivation of the Boltzmann-Peierls equation in the kinetic scaling limit of the discrete nonlinear Schödinger equation (DNLS) with suitable random initial data. We also present a reformulation of the standard perturbation expansion using cumulants, which could simplify the problem of a rigorous derivation of the Boltzmann-Peierls equation by separating the analysis of the solutions to the Boltzmann-Peierls equation from the analysis of the corrections. This latter scheme is general and not tied to the DNLS evolution equations.

  1. Reorganization of the Human Somatosensory Cortex in Hand Dystonia

    Directory of Open Access Journals (Sweden)

    Maria Jose Catalan

    2012-05-01

    Full Text Available Background and Purpose: Abnormalities of finger representations in the somatosensory cortex have been identified in patients with focal hand dystonia. Measuring blood flow with positron emission tomography (PET can be use to demonstrate functional localization of receptive fields. Methods: A vibratory stimulus was applied to the right thumb and little finger of six healthy volunteers and six patients with focal hand dystonia to map their receptive fields using H215O PET. Results: The cortical finger representations in the primary somatosensory cortex were closer to each other in patients than in normal subjects. No abnormalities were found in secondary somatosensory cortex, but the somatotopy there is less well distinguished. Conclusions: These data confirm prior electrophysiological and functional neuroimaging observations showing abnormalities of finger representations in somatosensory cortex of patients with focal hand dystonia.

  2. Influence of dopaminergically mediated reward on somatosensory decision-making.

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    Burkhard Pleger

    2009-07-01

    Full Text Available Reward-related dopaminergic influences on learning and overt behaviour are well established, but any influence on sensory decision-making is largely unknown. We used functional magnetic resonance imaging (fMRI while participants judged electric somatosensory stimuli on one hand or other, before being rewarded for correct performance at trial end via a visual signal, at one of four anticipated financial levels. Prior to the procedure, participants received either placebo (saline, a dopamine agonist (levodopa, or an antagonist (haloperidol.higher anticipated reward improved tactile decisions. Visually signalled reward reactivated primary somatosensory cortex for the judged hand, more strongly for higher reward. After receiving a higher reward on one trial, somatosensory activations and decisions were enhanced on the next trial. These behavioural and neural effects were all enhanced by levodopa and attenuated by haloperidol, indicating dopaminergic dependency. Dopaminergic reward-related influences extend even to early somatosensory cortex and sensory decision-making.

  3. Dissociating vestibular and somatosensory contributions to spatial orientation

    NARCIS (Netherlands)

    Alberts, B.B.G.T.; Selen, L.P.J.; Bertolini, G.; Straumann, D.; Medendorp, W.P.; Tarnutzer, A.A.

    2016-01-01

    Inferring object orientation in the surroundings heavily depends on our internal sense of direction of gravity. Previous research showed that this sense is based on the integration of multiple information sources, including visual, vestibular (otolithic) and somatosensory signals. The individual

  4. An Intelligent Decision System for Intraoperative Somatosensory Evoked Potential Monitoring.

    Science.gov (United States)

    Fan, Bi; Li, Han-Xiong; Hu, Yong

    2016-02-01

    Somatosensory evoked potential (SEP) is a useful, noninvasive technique widely used for spinal cord monitoring during surgery. One of the main indicators of a spinal cord injury is the drop in amplitude of the SEP signal in comparison to the nominal baseline that is assumed to be constant during the surgery. However, in practice, the real-time baseline is not constant and may vary during the operation due to nonsurgical factors, such as blood pressure, anaesthesia, etc. Thus, a false warning is often generated if the nominal baseline is used for SEP monitoring. In current practice, human experts must be used to prevent this false warning. However, these well-trained human experts are expensive and may not be reliable and consistent due to various reasons like fatigue and emotion. In this paper, an intelligent decision system is proposed to improve SEP monitoring. First, the least squares support vector regression and multi-support vector regression models are trained to construct the dynamic baseline from historical data. Then a control chart is applied to detect abnormalities during surgery. The effectiveness of the intelligent decision system is evaluated by comparing its performance against the nominal baseline model by using the real experimental datasets derived from clinical conditions.

  5. Dynamical activities of primary somatosensory cortices studied by magnetoencephalography

    Science.gov (United States)

    Kishida, Kuniharu

    2009-11-01

    A blind identification method of transfer functions in feedback systems is introduced for examination of dynamical activities of cortices by magnetoencephalography study. Somatosensory activities are examined in 5 Hz periodical median nerve stimulus. In the present paper, we will try two careful preprocessing procedures for the identification method to obtain impulse responses between primary somatosensory cortices. Time series data of the somatosensory evoked field are obtained by using a blind source separation of the T/k type (fractional) decorrelation method. Time series data of current dipoles of primary somatosensory cortices are transformed from the time series data of the somatosensory evoked field by the inverse problem. Fluctuations of current dipoles of them are obtained after elimination of deterministic periodical evoked waveforms. An identification method based on feedback system theory is used for estimation of transfer functions in a feedback model from obtained fluctuations of currents dipoles of primary somatosensory cortices. Dynamical activities between them are presented by Bode diagrams of transfer functions and their impulse responses: the time delay of about 30 ms via corpus callosum is found in the impulse response of identified transfer function.

  6. Somatosensory shift of postural control in dizzy patients.

    Science.gov (United States)

    Okumura, Tomoko; Horii, Arata; Kitahara, Tadashi; Imai, Takao; Uno, Atsuhiko; Osaki, Yasuhiro; Inohara, Hidenori

    2015-09-01

    Postural control is dependent on the visual system in normal conditions. Shift from visual to somatosensory dependence in dizzy patients suggests that utilizing the stable visual references is recommended for the rehabilitation of dizzy patients. To investigate which of the visual or somatosensory system is mainly used for substitution of the impaired spatial orientation in dizzy patients. We recruited 189 consecutive patients with or without dizziness and vestibular dysfunction. Dizzy patients were divided into three groups: acute, episodic, and chronic dizziness. Vestibular function was assessed by caloric test, traditional head impulse test, and head shaking nystagmus. Visual or somatosensory dependence of spatial orientation was assessed by posturography on a solid surface or on foam in eyes open or closed condition. The foam ratio (posturography with/without foam) when eyes were closed was indicative of somatosensory dependence of postural control, whereas the Romberg ratio on foam showed visual dependence. (Romberg ratio on foam)/(foam ratio with eyes closed) was calculated and used as an index of the visual/somatosensory dependence of postural control. The visual/somatosensory ratio of postural control was significantly lower in dizzy patients as well as patients with vestibular dysfunction, however, no differences were found between acute, episodic, and chronic dizziness.

  7. Molecular and cellular limits to somatosensory specificity

    Directory of Open Access Journals (Sweden)

    Viana Félix

    2008-04-01

    Full Text Available Abstract Animals detect environmental changes through sensory neural mechanisms that enable them to differentiate the quality, intensity and temporal characteristics of stimuli. The 'doctrine of specific nervous energies' postulates that the different sensory modalities experienced by humans result of the activation of specific nervous pathways. Identification of functional classes of sensory receptors provided scientific support to the concept that somatosensory modalities (touch, pain, temperature, kinesthesis are subserved by separate populations of sensory receptor neurons specialized in detecting innocuous and injurious stimuli of different quality (mechanical forces, temperature, chemical compounds. The identification of receptor proteins activated by different physicochemical stimuli, in particular ion channels of the Transient Receptor Potential (TRP superfamily, has put forward the concept that specificity of peripheral sensory receptor neurons is determined by their expression of a particular "molecular sensor" that confers to each functional type its selectivity to respond with a discharge of nerve impulses to stimuli of a given quality. Nonetheless, recent experimental data suggest that the various molecular sensors proposed as specific transducer molecules for stimuli of different quality are not as neatly associated with the distinct functional types of sensory receptors as originally proposed. First, many ion channel molecules initially associated to the transduction of only one particular form of energy are also activated by stimuli of different quality, implying a limited degree of specificity in their transducing capacities. Second, molecular sensors associated with a stimulus quality and hence to a sensory receptor type and ultimately to a sensory modality may be concomitantly expressed in sensory receptor neurons functionally defined as specific for another stimulus quality. Finally, activation of voltage gated channels

  8. Relationship between somatosensory deficit and brain somatosensory system after early brain lesion: A morphometric study.

    Science.gov (United States)

    Perivier, Maximilien; Delion, Matthieu; Chinier, Eva; Loustau, Sebastien; Nguyen, Sylvie; Ter Minassian, Aram; Richard, Isabelle; Dinomais, Mickael

    2016-05-01

    Cerebral Palsy (CP) is a group of permanent motor disorders due to non-progressive damage to the developing brain. Poor tactile discrimination is common in children with unilateral CP. Previous findings suggest the crucial role of structural integrity of the primary (S1) and secondary (S2) somatosensory areas located in the ipsilesional hemisphere for somatosensory function processing. However, no focus on the relationship between structural characteristics of ipsilesional S1 and S2 and tactile discrimination function in paretic hands has been proposed. Using structural MRI and a two-point discrimination assessment (2 PD), we explore this potential link in a group of 21 children (mean age 13 years and 7 months) with unilateral CP secondary to a periventricular white matter injury (PWMI) or middle cerebral artery infarct (MCA). For our whole sample there was a significant negative correlation between the 2 PD and the gray matter volume in the ipsilesional S2 (rho = -0.50 95% confidence interval [-0.76, -0.08], one-tailed p-value = 0.0109) and in the ipsilesional S1 (rho = -0.57, 95% confidence interval [-0.81, -0.19], one-tailed p-value = 0.0032). When studying these relationships with regard to the lesion types, we found these correlations were non-significant in the patients with PWMI but stronger in patients with MCA. According to our results, the degree of sensory impairment is related to the spared gray matter volume in ipsilesional S1 and S2 and is marked after an MCA stroke. Our work contributes to a better understanding of why some patients with CP have variable somatosensory deficit following an early brain lesion. Copyright © 2015 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

  9. Electro-cumulation CNF project

    CERN Document Server

    Grishin, V G

    2000-01-01

    bound or free ion current within solid substances; non-plain symmetry; cumulation of the ion interaction. Experimental result: an Ice SuperPolarization. Cold nuclear fusion ? At http://www.shortway.to/to2084 . Keywords: ion, current, solid, symmetry, cumulation, cold nuclear fusion, polarization, depolarization, ionic conductor, superionic conductor, ice, crystal, strain, V-center, V-centre, doped crystal, interstitial impurity, intrinsic color center, high pressure technology, Bridgman, experiment, crowdion, dielectric, proton, layer, defect, lattice, dynamics, electromigration, mobility, muon catalysis, concentration, doping, dopant, conductivity, pycnonuclear reaction, permittivity, dielectric constant, point defects, interstitials, polarizability, imperfection, defect centers, glass, epitaxy, sodium hydroxide, metallic substrate, crystallization, point, tip, susceptibility, ferroelectric, ordering, force, correlation, collective, shift, distortion, coalescence, crowdions, electrolysis.

  10. Pathophysiology of somatosensory abnormalities in Parkinson disease.

    Science.gov (United States)

    Conte, Antonella; Khan, Nashaba; Defazio, Giovanni; Rothwell, John C; Berardelli, Alfredo

    2013-12-01

    Changes in sensory function that have been described in patients with Parkinson disease (PD) can be either 'pure' disorders of conscious perception such as elevations in sensory threshold, or disorders of sensorimotor integration, in which the interaction between sensory input and motor output is altered. In this article, we review the extensive evidence for disrupted tactile, nociceptive, thermal and proprioceptive sensations in PD, as well as the influences exerted on these sensations by dopaminergic therapy and deep brain stimulation. We argue that abnormal spatial and temporal processing of sensory information produces incorrect signals for the preparation and execution of voluntary movement. Sensory deficits are likely to be a consequence of the dopaminergic denervation of the basal ganglia that is the hallmark of PD. A possible mechanism to account for somatosensory deficits is one in which disease-related dopaminergic denervation leads to a loss of response specificity, resulting in transmission of noisier and less-differentiated information to cortical regions. Changes in pain perception might have a different explanation, possibly involving disease-related effects outside the basal ganglia, including involvement of peripheral pain receptors, as well as structures such as the periaqueductal grey matter and non-dopaminergic neurotransmitter systems.

  11. Frequency specific modulation of human somatosensory cortex

    Directory of Open Access Journals (Sweden)

    Matteo eFeurra

    2011-02-01

    Full Text Available Oscillatory neuronal activities are commonly observed in response to sensory stimulation. However, their functional roles are still the subject of debate. One way to probe the roles of oscillatory neural activities is to deliver alternating current to the cortex at biologically relevant frequencies and examine whether such stimulation influences perception and cognition. In this study, we tested whether transcranial alternating current stimulation (tACS over the primary somatosensory cortex (SI could elicit tactile sensations in humans in a frequency dependent manner. We tested the effectiveness of tACS over SI at frequency bands ranging from 2 to 70 Hz. Our results show that stimulation in alpha (10-14 Hz and high gamma (52-70 Hz frequency range produces a tactile sensation in the contralateral hand. A weaker effect was also observed for beta (16-20 Hz stimulation. These findings highlight the frequency-dependency of effective tACS over SI with the effective frequencies corresponding to those observed in previous EEG/MEG studies of tactile perception. Our present study suggests that tACS could be used as a powerful online stimulation technique to reveal the causal roles of oscillatory brain activities.

  12. Critical Factors for Inducing Curved Somatosensory Saccades

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    Tamami Nakano

    2011-10-01

    Full Text Available We are able to make a saccade toward a tactile stimuli to one hand, but trajectories of many saccades curved markedly when the arms were crossed (Groh & Sparks, 2006. However, it remains unknown why some curved and others did not. We therefore examined critical factors for inducing the curved somatosensory saccades. Participants made a saccade as soon as possible from a central fixation point toward a tactile stimulus delivered to one of the two hands, and switched between arms-crossed and arms-uncrossed postures every 6 trials. Trajectories were generally straight when the arms were uncrossed, but all participants made curved saccades when the arms were crossed (12–64%. We found that the probability of curved saccades depended critically on the onset latency: the probability was less than 5% when the latency was larger than 250 ms, but the probability increased up to 70–80% when the onset latency was 160 ms. This relationship was shared across participants. The results suggest that a touch in the arms-crossed posture was always mapped to the wrong hand in the initial phase up to 160 ms, and then remapped to the correct hand during the next 100 ms by some fundamental neural mechanisms shared across participants.

  13. Functional Plasticity in Somatosensory Cortex Supports Motor Learning by Observing.

    Science.gov (United States)

    McGregor, Heather R; Cashaback, Joshua G A; Gribble, Paul L

    2016-04-04

    An influential idea in neuroscience is that the sensory-motor system is activated when observing the actions of others [1, 2]. This idea has recently been extended to motor learning, in which observation results in sensory-motor plasticity and behavioral changes in both motor and somatosensory domains [3-9]. However, it is unclear how the brain maps visual information onto motor circuits for learning. Here we test the idea that the somatosensory system, and specifically primary somatosensory cortex (S1), plays a role in motor learning by observing. In experiment 1, we applied stimulation to the median nerve to occupy the somatosensory system with unrelated inputs while participants observed a tutor learning to reach in a force field. Stimulation disrupted motor learning by observing in a limb-specific manner. Stimulation delivered to the right arm (the same arm used by the tutor) disrupted learning, whereas left arm stimulation did not. This is consistent with the idea that a somatosensory representation of the observed effector must be available during observation for learning to occur. In experiment 2, we assessed S1 cortical processing before and after observation by measuring somatosensory evoked potentials (SEPs) associated with median nerve stimulation. SEP amplitudes increased only for participants who observed learning. Moreover, SEPs increased more for participants who exhibited greater motor learning following observation. Taken together, these findings support the idea that motor learning by observing relies on functional plasticity in S1. We propose that visual signals about the movements of others are mapped onto motor circuits for learning via the somatosensory system. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Congruency of body-related information induces somatosensory reorganization.

    Science.gov (United States)

    Cardini, Flavia; Longo, Matthew R

    2016-04-01

    Chronic pain and impaired tactile sensitivity are frequently associated with "blurred" representations in the somatosensory cortex. The factors that produce such somatosensory blurring, however, remain poorly understood. We manipulated visuo-tactile congruence to investigate its role in promoting somatosensory reorganization. To this aim we used the mirror box illusion that produced in participants the subjective feeling of looking directly at their left hand, though they were seeing the reflection of their right hand. Simultaneous touches were applied to the middle or ring finger of each hand. In one session, the same fingers were touched (for example both middle fingers), producing a congruent percept; in the other session different fingers were touched, producing an incongruent percept. In the somatosensory system, suppressive interactions between adjacent stimuli are an index of intracortical inhibitory function. After each congruent and incongruent session, we recorded somatosensory evoked potential (SEPs) elicited by electrocutaneous stimulation of the left ring and middle fingers, either individually or simultaneously. A somatosensory suppression index (SSI) was calculated as the difference in amplitude between the sum of potentials evoked by the two individually stimulated fingers and the potentials evoked by simultaneous stimulation of both fingers. This SSI can be taken as an index of the strength of inhibitory interactions and consequently can provide a measure of how distinct the representations of the two fingers are. Results showed stronger SSI in the P100 component after congruent than incongruent stimulation, suggesting the key role of congruent sensory information about the body in inducing somatosensory reorganization. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Pathophysiology, Diagnosis and Treatment of Somatosensory Tinnitus: A Scoping Review

    Directory of Open Access Journals (Sweden)

    Haúla F. Haider

    2017-04-01

    Full Text Available Somatosensory tinnitus is a generally agreed subtype of tinnitus that is associated with activation of the somatosensory, somatomotor, and visual-motor systems. A key characteristic of somatosensory tinnitus is that is modulated by physical contact or movement. Although it seems common, its pathophysiology, assessment and treatment are not well defined. We present a scoping review on the pathophysiology, diagnosis, and treatment of somatosensory tinnitus, and identify priority directions for further research.Methods: Literature searches were conducted in Google Scholar, PubMed, and EMBASE databases. Additional broad hand searches were conducted with the additional terms etiology, diagnose, treatment.Results: Most evidence on the pathophysiology of somatosensory tinnitus suggests that somatic modulations are the result of altered or cross-modal synaptic activity within the dorsal cochlear nucleus or between the auditory nervous system and other sensory subsystems of central nervous system (e.g., visual or tactile. Presentations of somatosensory tinnitus are varied and evidence for the various approaches to treatment promising but limited.Discussion and Conclusions: Despite the apparent prevalence of somatosensory tinnitus its underlying neural processes are still not well understood. Necessary involvement of multidisciplinary teams in its diagnosis and treatment has led to a large heterogeneity of approaches whereby tinnitus improvement is often only a secondary effect. Hence there are no evidence-based clinical guidelines, and patient care is empirical rather than research-evidence-based. Somatic testing should receive further attention considering the breath of evidence on the ability of patients to modulate their tinnitus through manouvers. Specific questions for further research and review are indicated.

  16. Barrier function and natural moisturizing factor levels after cumulative exposure to a fruit-derived organic acid and a detergent: different outcomes in atopic and healthy skin and relevance for occupational contact dermatitis in the food industry

    NARCIS (Netherlands)

    Angelova-Fischer, Irena; Hoek, Anne-Karin; Dapic, Irena; Jakasa, Ivone; Kezic, Sanja; Fischer, Tobias W.; Zillikens, Detlef

    2015-01-01

    Fruit-derived organic compounds and detergents are relevant exposure factors for occupational contact dermatitis in the food industry. Although individuals with atopic dermatitis (AD) are at risk for development of occupational contact dermatitis, there have been no controlled studies on the effects

  17. Cumulative prospect theory and mean variance analysis. A rigorous comparison

    OpenAIRE

    Hens, Thorsten; Mayer, Janos

    2012-01-01

    We compare asset allocations derived for cumulative prospect theory(CPT) based on two different methods: Maximizing CPT along the mean–variance efficient frontier and maximizing it without that restriction. We find that with normally distributed returns the difference is negligible. However, using standard asset allocation data of pension funds the difference is considerable. Moreover, with derivatives like call options the restriction to the mean-variance efficient frontier results in a siza...

  18. Interhemispheric interactions between the human primary somatosensory cortices.

    Directory of Open Access Journals (Sweden)

    Patrick Ragert

    Full Text Available In the somatosensory domain it is still unclear at which processing stage information reaches the opposite hemispheres. Due to dense transcallosal connections, the secondary somatosensory cortex (S2 has been proposed to be the key candidate for interhemispheric information transfer. However, recent animal studies showed that the primary somatosensory cortex (S1 might as well account for interhemispheric information transfer. Using paired median nerve somatosensory evoked potential recordings in humans we tested the hypothesis that interhemispheric inhibitory interactions in the somatosensory system occur already in an early cortical processing stage such as S1. Conditioning right S1 by electrical median nerve (MN stimulation of the left MN (CS resulted in a significant reduction of the N20 response in the target (left S1 relative to a test stimulus (TS to the right MN alone when the interstimulus interval between CS and TS was between 20 and 25 ms. No such changes were observed for later cortical components such as the N20/P25, N30, P40 and N60 amplitude. Additionally, the subcortically generated P14 response in left S1 was also not affected. These results document the existence of interhemispheric inhibitory interactions between S1 in human subjects in the critical time interval of 20-25 ms after median nerve stimulation.

  19. Reduced functional connectivity of somatosensory network in writer's cramp patients.

    Science.gov (United States)

    Cheng, Chia-Hsiung; Tseng, Yi-Jhan; Chen, Rou-Shayn; Lin, Yung-Yang

    2016-03-01

    The involvement of motor cortex and sensorimotor integration in patients with writer's cramp (WC) has been well documented. However, the exact neurophysiological profile within the somatosensory system, including primary somatosensory cortex (SI), contralateral (SIIc), and ipsilateral (SIIi) secondary somatosensory areas remains less understood. This study investigated the neuromagnetic cortical activities of median nerve stimulation in 10 patients with WC and 10 healthy controls (HC). To comprehensively explore all the aspects of somatosensory functioning, we analyzed our data with the minimum norm estimate (MNE), the time-frequency approach with evoked and induced activities, and functional connectivity between SI and SIIc (SI-SIIc), SI and SIIi (SI-SIIi), and SIIc and SIIi (SIIc-SIIi) from theta to gamma oscillations. No significant between-group differences were found in the MNE cortical amplitudes of SI, SIIc, and SIIi. Power strengths of evoked gamma oscillation and induced beta synchronization were also equivalent between WC and HC groups. However, we found significantly reduced theta coherence of SI-SIIi, alpha coherence of SI-SIIi and SIIc-SIIi, as well as beta coherence of SIIc-SIIi in patients with WC. Our results suggest the involvement of somatosensory abnormalities, primarily with the form of functional connectivity, in patients with WC.

  20. Somatosensory system hyperexcitability in alternating hemiplegia of childhood.

    Science.gov (United States)

    Vollono, C; Rinalduzzi, S; Miliucci, R; Vigevano, F; Valeriani, M

    2014-12-01

    Alternating hemiplegia of childhood (AHC) is a rare neurological disease characterized by recurrent paroxysmal attacks of hemiplegia. The aim of the study was to assess the recovery cycle of the somatosensory evoked potentials (SEPs) in a group of AHC patients. Seven AHC patients and 10 control age-matched subjects (CS) were recruited. Right and left median nerve SEPs were recorded. The somatosensory system excitability was assessed by calculating the SEP changes after paired electrical stimuli. All patients were studied during the interictal phase, whilst four patients were studied also during the ictal phase. In AHC patients during the interictal phase, the amplitudes of the cervical N13 and of the cortical N20, P24 and N30 responses showed a faster recovery than in CS. In AHC patients during the ictal phase, the cortical N20 recovery cycle was prolonged compared with the interictal phase. A shortened SEP recovery cycle in AHC during the interictal phase suggests multilevel somatosensory system hyperexcitability in AHC. A partial recovery of this phenomenon during the ictal phase possibly reflects a functional reset of the somatosensory system. Overall, there is a disinhibition of the somatosensory system in AHC, a functional change of brain function associated with a possible involvement of the Na(+) /K(+) channels. This abnormality and its partial recovery during the attacks might be linked to the pathophysiological and genetic mechanisms of the disease. © 2014 EAN.

  1. Pudendal somatosensory evoked potentials in normal women

    Directory of Open Access Journals (Sweden)

    Geraldo A. Cavalcanti

    2007-12-01

    Full Text Available OBJECTIVE: Somatosensory evoked potential (SSEP is an electrophysiological test used to evaluate sensory innervations in peripheral and central neuropathies. Pudendal SSEP has been studied in dysfunctions related to the lower urinary tract and pelvic floor. Although some authors have already described technical details pertaining to the method, the standardization and the influence of physiological variables in normative values have not yet been established, especially for women. The aim of the study was to describe normal values of the pudendal SSEP and to compare technical details with those described by other authors. MATERIALS AND METHODS: The clitoral sensory threshold and pudendal SSEP latency was accomplished in 38 normal volunteers. The results obtained from stimulation performed on each side of the clitoris were compared to ages, body mass index (BMI and number of pregnancies. RESULTS: The values of clitoral sensory threshold and P1 latency with clitoral left stimulation were respectively, 3.64 ± 1.01 mA and 37.68 ± 2.60 ms. Results obtained with clitoral right stimulation were 3.84 ± 1.53 mA and 37.42 ± 3.12 ms, respectively. There were no correlations between clitoral sensory threshold and P1 latency with age, BMI or height of the volunteers. A significant difference was found in P1 latency between nulliparous women and volunteers who had been previously submitted to cesarean section. CONCLUSIONS: The SSEP latency represents an accessible and reproducible method to investigate the afferent pathways from the genitourinary tract. These results could be used as normative values in studies involving genitourinary neuropathies in order to better clarify voiding and sexual dysfunctions in females.

  2. The Algebra of the Cumulative Percent Operation.

    Science.gov (United States)

    Berry, Andrew J.

    2002-01-01

    Discusses how to help students avoid some pervasive reasoning errors in solving cumulative percent problems. Discusses the meaning of ."%+b%." the additive inverse of ."%." and other useful applications. Emphasizes the operational aspect of the cumulative percent concept. (KHR)

  3. Adaptive strategies for cumulative cultural learning.

    Science.gov (United States)

    Ehn, Micael; Laland, Kevin

    2012-05-21

    The demographic and ecological success of our species is frequently attributed to our capacity for cumulative culture. However, it is not yet known how humans combine social and asocial learning to generate effective strategies for learning in a cumulative cultural context. Here we explore how cumulative culture influences the relative merits of various pure and conditional learning strategies, including pure asocial and social learning, critical social learning, conditional social learning and individual refiner strategies. We replicate the Rogers' paradox in the cumulative setting. However, our analysis suggests that strategies that resolved Rogers' paradox in a non-cumulative setting may not necessarily evolve in a cumulative setting, thus different strategies will optimize cumulative and non-cumulative cultural learning. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Impaired somatosensory discrimination of shape in Parkinson's disease : Association with caudate nucleus dopaminergic function

    NARCIS (Netherlands)

    Weder, BJ; Leenders, KL; Vontobel, P; Nienhusmeier, M; Keel, A; Zaunbauer, W; Vonesch, T; Ludin, HP

    1999-01-01

    Tactile discrimination of macrogeometric objects in a two-alternative forced-choice procedure represents a demanding task involving somatosensory pathways and higher cognitive processing. The objects for somatosensory discrimination, i.e., rectangular parallelepipeds differing only in oblongness,

  5. Impairing somatosensory working memory using rTMS.

    Science.gov (United States)

    Auksztulewicz, Ryszard; Spitzer, Bernhard; Goltz, Dominique; Blankenburg, Felix

    2011-09-01

    Numerous studies in animals and humans have related central aspects of somatosensory working memory function to neural activity in the inferior frontal gyrus (IFG). However, as previous studies have almost exclusively used correlational analyses, the question whether sustained neural activity in the IFG is causally involved in successful maintenance of somatosensory information remains unanswered. We used an online repetitive transcranial magnetic stimulation (rTMS) protocol to disrupt neuronal activity in the IFG while participants were maintaining tactile information throughout the delay for later comparison against a probe stimulus. rTMS impaired participants' performance in the working memory task, but not in a physically matched perceptual control task. Targeting the IFG in either hemisphere led to comparable working memory impairment. Our results show that the neural activity in the IFG plays a causal role in successful maintenance of somatosensory information. © 2011 The Authors. European Journal of Neuroscience © 2011 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

  6. A paradox of cumulative culture.

    Science.gov (United States)

    Kobayashi, Yutaka; Wakano, Joe Yuichiro; Ohtsuki, Hisashi

    2015-08-21

    Culture can grow cumulatively if socially learnt behaviors are improved by individual learning before being passed on to the next generation. Previous authors showed that this kind of learning strategy is unlikely to be evolutionarily stable in the presence of a trade-off between learning and reproduction. This is because culture is a public good that is freely exploited by any member of the population in their model (cultural social dilemma). In this paper, we investigate the effect of vertical transmission (transmission from parents to offspring), which decreases the publicness of culture, on the evolution of cumulative culture in both infinite and finite population models. In the infinite population model, we confirm that culture accumulates largely as long as transmission is purely vertical. It turns out, however, that introduction of even slight oblique transmission drastically reduces the equilibrium level of culture. Even more surprisingly, if the population size is finite, culture hardly accumulates even under purely vertical transmission. This occurs because stochastic extinction due to random genetic drift prevents a learning strategy from accumulating enough culture. Overall, our theoretical results suggest that introducing vertical transmission alone does not really help solve the cultural social dilemma problem. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Diagnosis and management of somatosensory tinnitus: review article.

    Science.gov (United States)

    Sanchez, Tanit Ganz; Rocha, Carina Bezerra

    2011-01-01

    Tinnitus is the perception of sound in the absence of an acoustic external stimulus. It affects 10-17% of the world's population and it a complex symptom with multiple causes, which is influenced by pathways other than the auditory one. Recently, it has been observed that tinnitus may be provoked or modulated by stimulation arising from the somatosensorial system, as well as from the somatomotor and visual-motor systems. This specific subgroup -somatosensory tinnitus - is present in 65% of cases, even though it tends to be underdiagnosed. As a consequence, it is necessary to establish evaluation protocols and specific treatments focusing on both the auditory pathway and the musculoskeletal system.

  8. Auditory-somatosensory temporal sensitivity improves when the somatosensory event is caused by voluntary body movement

    Directory of Open Access Journals (Sweden)

    Norimichi Kitagawa

    2016-12-01

    Full Text Available When we actively interact with the environment, it is crucial that we perceive a precise temporal relationship between our own actions and sensory effects to guide our body movements.Thus, we hypothesized that voluntary movements improve perceptual sensitivity to the temporal disparity between auditory and movement-related somatosensory events compared to when they are delivered passively to sensory receptors. In the voluntary condition, participants voluntarily tapped a button, and a noise burst was presented at various onset asynchronies relative to the button press. The participants made either 'sound-first' or 'touch-first' responses. We found that the performance of temporal order judgment (TOJ in the voluntary condition (as indexed by the just noticeable difference was significantly better (M=42.5 ms ±3.8 s.e.m than that when their finger was passively stimulated (passive condition: M=66.8 ms ±6.3 s.e.m. We further examined whether the performance improvement with voluntary action can be attributed to the prediction of the timing of the stimulation from sensory cues (sensory-based prediction, kinesthetic cues contained in voluntary action, and/or to the prediction of stimulation timing from the efference copy of the motor command (motor-based prediction. When the participant’s finger was moved passively to press the button (involuntary condition and when three noise bursts were presented before the target burst with regular intervals (predictable condition, the TOJ performance was not improved from that in the passive condition. These results suggest that the improvement in sensitivity to temporal disparity between somatosensory and auditory events caused by the voluntary action cannot be attributed to sensory-based prediction and kinesthetic cues. Rather, the prediction from the efference copy of the motor command would be crucial for improving the temporal sensitivity.

  9. Primary somatosensory cortex discriminates affective significance in social touch

    NARCIS (Netherlands)

    Gazzola, Valeria; Spezio, Michael L.; Etzel, Joset A.; Castelli, Fulvia; Adolphs, Ralph; Keysers, Christian

    2012-01-01

    Another person's caress is one of the most powerful of all emotional social signals. How much the primary somatosensory cortices (SIs) participate in processing the pleasantness of such social touch remains unclear. Although ample empirical evidence supports the role of the insula in affective

  10. Neural mechanisms of selective attention in the somatosensory system

    Science.gov (United States)

    Hysaj, Kristjana; Niebur, Ernst

    2016-01-01

    Selective attention allows organisms to extract behaviorally relevant information while ignoring distracting stimuli that compete for the limited resources of their central nervous systems. Attention is highly flexible, and it can be harnessed to select information based on sensory modality, within-modality feature(s), spatial location, object identity, and/or temporal properties. In this review, we discuss the body of work devoted to understanding mechanisms of selective attention in the somatosensory system. In particular, we describe the effects of attention on tactile behavior and corresponding neural activity in somatosensory cortex. Our focus is on neural mechanisms that select tactile stimuli based on their location on the body (somatotopic-based attention) or their sensory feature (feature-based attention). We highlight parallels between selection mechanisms in touch and other sensory systems and discuss several putative neural coding schemes employed by cortical populations to signal the behavioral relevance of sensory inputs. Specifically, we contrast the advantages and disadvantages of using a gain vs. spike-spike correlation code for representing attended sensory stimuli. We favor a neural network model of tactile attention that is composed of frontal, parietal, and subcortical areas that controls somatosensory cells encoding the relevant stimulus features to enable preferential processing throughout the somatosensory hierarchy. Our review is based on data from noninvasive electrophysiological and imaging data in humans as well as single-unit recordings in nonhuman primates. PMID:27334956

  11. Neural correlates of human somatosensory integration in tinnitus

    NARCIS (Netherlands)

    Lanting, C. P.; de Kleine, E.; Eppinga, R. N.; van Dijk, P.

    2010-01-01

    Possible neural correlates of somatosensory modulation of tinnitus were assessed. Functional magnetic resonance imaging (fMRI) was used to investigate differences in neural activity between subjects that can modulate their tinnitus by jaw protrusion and normal hearing controls. We measured responses

  12. Preserved somatosensory discrimination predicts consciousness recovery in unresponsive wakefulness syndrome.

    Science.gov (United States)

    Spataro, Rossella; Heilinger, Alexander; Allison, Brendan; De Cicco, Domenico; Marchese, Santino; Gregoretti, Cesare; La Bella, Vincenzo; Guger, Christoph

    2018-03-12

    To assess somatosensory discrimination and command following using a vibrotactile P300-based Brain-Computer Interface (BCI) in Unresponsive Wakefulness Syndrome (UWS), and investigate the predictive role of this cognitive process on the clinical outcomes. Thirteen UWS patients and six healthy controls each participated in two experimental runs in which they were instructed to count vibrotactile stimuli delivered to the left or right wrist. A BCI determined each subject's task performance based on EEG measures. All of the patients were followed up six months after the BCI assessment, and correlations analysis between accuracy rates and clinical outcome were investigated. Four UWS patients demonstrated clear EEG-based indices of task following in one or both paradigms, which did not correlate with clinical factors. The efficacy of somatosensory discrimination strongly correlated (VT2: R = 0.89, p = 0.0000002, VT3: R = 0.81, p = 0.002) with the clinical outcome at 6-months. The BCI system also yielded the expected results with healthy controls. Neurophysiological correlates of somatosensory discrimination can be detected in clinically unresponsive patients and are associated with recovery of behavioural responsiveness at six months. Quantitative measurements of somatosensory discrimination may increase the diagnostic accuracy of persons with DOCs and provide useful prognostic information. Copyright © 2018 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

  13. Working memory of somatosensory stimuli: an fMRI study.

    Science.gov (United States)

    Savini, Nicoletta; Brunetti, Marcella; Babiloni, Claudio; Ferretti, Antonio

    2012-12-01

    In a previous study, we have shown that passive recognition of tactile geometrical shapes (i.e. no exploratory movement) engages prefrontal and premotor areas in addition to somatosensory regions (Savini et al., 2010). In the present study we tested the hypothesis that these regions are involved not only in the perception but also during working memory of such somatic information. We performed functional magnetic resonance imaging (fMRI) during the execution of N-BACK tasks, with 2D geometrical shapes blindly pressed on the subjects' right hand palm. Three conditions with increasing memory load (0-BACK, 1-BACK, 2-BACK) were used. Results showed that primary somatosensory area (SI), secondary somatosensory area (SII) and bilateral Insula were active in all conditions, confirming their importance in coding somatosensory stimuli. Activation of fronto-parietal circuit in supplementary motor area (SMA), right superior parietal lobe (rSPL), bilateral middle frontal gyrus, left inferior frontal gyrus, and right superior frontal sulcus was significantly larger during 1-BACK and 2-BACK than 0-BACK. Left superior parietal lobe and right frontal eye field showed a higher activation during the 2-BACK than 0-BACK. Finally, SMA and rSPL were characterized by a statistically significant higher activation during 2-BACK than 1-BACK, revealing their sensitivity to the memory load. These results suggest that working memory of tactile geometrical shapes (no exploratory movement) involves a complex circuit of modal and supramodal fronto-parietal areas. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Neural mechanisms of selective attention in the somatosensory system.

    Science.gov (United States)

    Gomez-Ramirez, Manuel; Hysaj, Kristjana; Niebur, Ernst

    2016-09-01

    Selective attention allows organisms to extract behaviorally relevant information while ignoring distracting stimuli that compete for the limited resources of their central nervous systems. Attention is highly flexible, and it can be harnessed to select information based on sensory modality, within-modality feature(s), spatial location, object identity, and/or temporal properties. In this review, we discuss the body of work devoted to understanding mechanisms of selective attention in the somatosensory system. In particular, we describe the effects of attention on tactile behavior and corresponding neural activity in somatosensory cortex. Our focus is on neural mechanisms that select tactile stimuli based on their location on the body (somatotopic-based attention) or their sensory feature (feature-based attention). We highlight parallels between selection mechanisms in touch and other sensory systems and discuss several putative neural coding schemes employed by cortical populations to signal the behavioral relevance of sensory inputs. Specifically, we contrast the advantages and disadvantages of using a gain vs. spike-spike correlation code for representing attended sensory stimuli. We favor a neural network model of tactile attention that is composed of frontal, parietal, and subcortical areas that controls somatosensory cells encoding the relevant stimulus features to enable preferential processing throughout the somatosensory hierarchy. Our review is based on data from noninvasive electrophysiological and imaging data in humans as well as single-unit recordings in nonhuman primates. Copyright © 2016 the American Physiological Society.

  15. Somatosensory temporal discrimination is prolonged during migraine attacks.

    Science.gov (United States)

    Boran, H Evren; Cengiz, Bülent; Bolay, Hayrunnisa

    2016-01-01

    Symptoms and signs of sensorial disturbances are characteristic features of a migraine headache. Somatosensory temporal discrimination measures the temporal threshold to perceive two separate somaesthetic stimuli as clearly distinct. This study aimed to evaluate somaesthetic perception in migraine patients by measuring the somatosensory temporal discrimination thresholds. The study included 12 migraine patients without aura and 12 volunteers without headache. Somatosensory temporal discrimination threshold (STDT) values were measured in the face (V3) and hands (C7) during a lateralized headache attack and the headache-free interictal period. The disease duration, pain intensity, phonophobia, photophobia, nausea, vomiting, and brush allodynia were also recorded during the migraine attack. STDT values were within normal limits and not different between the control group and the interictal period in migraine patients. Compared to the headache-free period, STDT values during the attack were significantly prolonged in the contralateral hand (C7) (155.7 ± 84.2 vs 40.6 ± 16.1 ms [P face (V3) (65.5 ± 35.4 vs 37.6 ± 22.2 ms [P = .006]) and ipsilateral face (V3) (104.1 ± 44.5 vs 37.5 ± 21.4 ms [P face were significantly increased compared to that of the ipsilateral hand and contralateral face (155.7 ± 84.2 ms vs 88.6 ± 5.1.3 ms [P = .001], 104.1 ± 44.5 ms vs 65.5 ± 35.4 ms [P = 0.001]). No allodynia was detected in the areas that were tested for somatosensory temporal discrimination. The visual analog scale scores were correlated with the somatosensory temporal discrimination thresholds of the contralateral hand (r = 0.602, P = .038), whereas no correlation was detected between the somatosensory temporal discrimination thresholds and disease duration, brush allodynia in the forehead, phonophobia, photophobia, nausea and vomiting. The study demonstrates for the first time that somatosensory temporal

  16. Functional architecture of the somatosensory homunculus detected by electrostimulation.

    Science.gov (United States)

    Roux, Franck-Emmanuel; Djidjeli, Imène; Durand, Jean-Baptiste

    2017-12-29

    We performed a prospective electrostimulation study, based on 50 operated intact patients, to acquire accurate MNI coordinates of the functional areas of the somatosensory homunculus. In the contralateral BA1, the hand representation displayed not only medial-to-lateral, little-finger-to-thumb, but also rostral-to-caudal discrete somatotopy, with the tip of each finger located more caudally than the proximal phalanx. The analysis of the MNI body coordinates showed rare inter-individual variations in the medial-to-lateral somatotopic organization in these patients with rather different intensity thresholds needed to elicit sensations in different body parts. We found some similarities but also substantial differences with the previous, seminal works of Penfield and his colleagues. We propose a new drawing of the human somatosensory homunculus according to MNI space. In this prospective electrostimulation study, based on 50 operated patients with no sensory deficit and no brain lesion in the postcentral gyrus, we acquired coordinates in the standard MNI space of the functional areas of the somatosensory homunculus. The 3D brain volume of each patient was normalized to that space to obtain the MNI coordinates of the stimulation site locations. For 647 sites stimulated on Brodmann Area 1 (and 1025 in gyri nearby), 258 positive points for somatosensory response (40%) were found in the postcentral gyrus. In the contralateral BA1, the hand representation displayed not only medial-to-lateral and little-finger-to-thumb somatotopy, but also rostral-to-caudal discrete somatotopy, with the tip of each finger located more caudally than the proximal phalanx. We detected a medial-to-lateral, tip-to-base tongue organization but no rostral-to-caudal functional organization. The analysis of the MNI body coordinates showed rare inter-individual variations in the medial-to-lateral somatotopic organization in these patients with intact somatosensory cortex. Positive stimulations were

  17. Structure of a single whisker representation in layer 2 of mouse somatosensory cortex.

    Science.gov (United States)

    Clancy, Kelly B; Schnepel, Philipp; Rao, Antara T; Feldman, Daniel E

    2015-03-04

    Layer (L)2 is a major output of primary sensory cortex that exhibits very sparse spiking, but the structure of sensory representation in L2 is not well understood. We combined two-photon calcium imaging with deflection of many whiskers to map whisker receptive fields, characterize sparse coding, and quantitatively define the point representation in L2 of mouse somatosensory cortex. Neurons within a column-sized imaging field showed surprisingly heterogeneous, salt-and-pepper tuning to many different whiskers. Single whisker deflection elicited low-probability spikes in highly distributed, shifting neural ensembles spanning multiple cortical columns. Whisker-evoked response probability correlated strongly with spontaneous firing rate, but weakly with tuning properties, indicating a spectrum of inherent responsiveness across pyramidal cells. L2 neurons projecting to motor and secondary somatosensory cortex differed in whisker tuning and responsiveness, and carried different amounts of information about columnar whisker deflection. From these data, we derive a quantitative, fine-scale picture of the distributed point representation in L2. Copyright © 2015 the authors 0270-6474/15/353946-13$15.00/0.

  18. Change in Functional Arm Use Is Associated With Somatosensory Skills After Sensory Retraining Poststroke.

    Science.gov (United States)

    Turville, Megan; Carey, Leeanne M; Matyas, Thomas A; Blennerhassett, Jannette

    We investigated changes in functional arm use after retraining for stroke-related somatosensory loss and identified whether such changes are associated with somatosensory discrimination skills. Data were pooled (N = 80) from two randomized controlled trials of somatosensory retraining. We used the Motor Activity Log to measure perceived amount of arm use in daily activities and the Action Research Arm Test to measure performance capacity. Somatosensory discrimination skills were measured using standardized modality-specific measures. Participants' arm use improved after somatosensory retraining (z = -6.80, p arm use was weakly associated with somatosensation (tactile, β = 0.31, p .05; object recognition, β = 0.13, p arm use was related to a small amount of variance in somatosensory outcomes. Stroke survivors' functional arm use can increase after somatosensory retraining, with change varying among survivors. Copyright © 2017 by the American Occupational Therapy Association, Inc.

  19. Bilateral representations of touch in the primary somatosensory cortex.

    Science.gov (United States)

    Tamè, Luigi; Braun, Christoph; Holmes, Nicholas P; Farnè, Alessandro; Pavani, Francesco

    2016-01-01

    According to current textbook knowledge, the primary somatosensory cortex (SI) supports unilateral tactile representations, whereas structures beyond SI, in particular the secondary somatosensory cortex (SII), support bilateral tactile representations. However, dexterous and well-coordinated bimanual motor tasks require early integration of bilateral tactile information. Sequential processing, first of unilateral and subsequently of bilateral sensory information, might not be sufficient to accomplish these tasks. This view of sequential processing in the somatosensory system might therefore be questioned, at least for demanding bimanual tasks. Evidence from the last 15 years is forcing a revision of this textbook notion. Studies in animals and humans indicate that SI is more than a simple relay for unilateral sensory information and, together with SII, contributes to the integration of somatosensory inputs from both sides of the body. Here, we review a series of recent works from our own and other laboratories in favour of interactions between tactile stimuli on the two sides of the body at early stages of processing. We focus on tactile processing, although a similar logic may also apply to other aspects of somatosensation. We begin by describing the basic anatomy and physiology of interhemispheric transfer, drawing on neurophysiological studies in animals and behavioural studies in humans that showed tactile interactions between body sides, both in healthy and in brain-damaged individuals. Then we describe the neural substrates of bilateral interactions in somatosensation as revealed by neurophysiological work in animals and neuroimaging studies in humans (i.e., functional magnetic resonance imaging, magnetoencephalography, and transcranial magnetic stimulation). Finally, we conclude with considerations on the dilemma of how efficiently integrating bilateral sensory information at early processing stages can coexist with more lateralized representations of

  20. A new psychometric questionnaire for reporting of somatosensory percepts

    Science.gov (United States)

    Kim, L. H.; McLeod, R. S.; Kiss, Z. H. T.

    2018-02-01

    Objective. There have been remarkable advances over the past decade in neural prostheses to restore lost motor function. However, restoration of somatosensory feedback, which is essential for fine motor control and user acceptance, has lagged behind. With an increasing interest in using electrical stimulation to restore somatosensory sensations within the peripheral (PNS) and central nervous systems (CNS), it is critical to characterize the percepts evoked by electrical stimulation in a standardized manner with a validated psychometric questionnaire. This will allow comparison of results from applications at various nervous system levels in multiple settings. Approach. We compiled a summary of published reports of somatosensory percepts that were elicited by electrical stimulation in humans and used these to develop a new psychometric questionnaire. Results. This new questionnaire was able to characterize subjective evoked sensations with good test-retest reliability (Spearman’s correlation coefficients ranging 0.716  ⩽  ρ  ⩽  1.000, p  ⩽  0.005) in 13 subjects receiving stimulation through neural implants in both the CNS and PNS. Furthermore, the new questionnaire captured more descriptors (M  =  2.65, SD  =  0.91) that would have been missed by being categorized as ‘other sensations’, using a previous questionnaire (M  =  1.40, SD  =  0.77, t(12)  =  -10.24, p  <  0.001). Lastly, the new questionnaire was able to capture different descriptors within subjects using different patterns of electrical stimulation (Wilk’s Lambda  =  0.42, F(3, 10)  =  4.58, p  =  0.029). Significance. This new somatosensory psychometric questionnaire will aid in establishing consistency and standardization of reporting in future studies of somatosensory neural prostheses.

  1. Spatiotemporal integration of tactile information in human somatosensory cortex

    Directory of Open Access Journals (Sweden)

    Zumer Johanna M

    2007-03-01

    Full Text Available Abstract Background Our goal was to examine the spatiotemporal integration of tactile information in the hand representation of human primary somatosensory cortex (anterior parietal somatosensory areas 3b and 1, secondary somatosensory cortex (S2, and the parietal ventral area (PV, using high-resolution whole-head magnetoencephalography (MEG. To examine representational overlap and adaptation in bilateral somatosensory cortices, we used an oddball paradigm to characterize the representation of the index finger (D2; deviant stimulus as a function of the location of the standard stimulus in both right- and left-handed subjects. Results We found that responses to deviant stimuli presented in the context of standard stimuli with an interstimulus interval (ISI of 0.33s were significantly and bilaterally attenuated compared to deviant stimulation alone in S2/PV, but not in anterior parietal cortex. This attenuation was dependent upon the distance between the deviant and standard stimuli: greater attenuation was found when the standard was immediately adjacent to the deviant (D3 and D2 respectively, with attenuation decreasing for non-adjacent fingers (D4 and opposite D2. We also found that cutaneous mechanical stimulation consistently elicited not only a strong early contralateral cortical response but also a weak ipsilateral response in anterior parietal cortex. This ipsilateral response appeared an average of 10.7 ± 6.1 ms later than the early contralateral response. In addition, no hemispheric differences either in response amplitude, response latencies or oddball responses were found, independent of handedness. Conclusion Our findings are consistent with the large receptive fields and long neuronal recovery cycles that have been described in S2/PV, and suggest that this expression of spatiotemporal integration underlies the complex functions associated with this region. The early ipsilateral response suggests that anterior parietal fields also

  2. Somatosensory abnormalities in atypical odontalgia: A case-control study.

    Science.gov (United States)

    List, Thomas; Leijon, Göran; Svensson, Peter

    2008-10-15

    Somatosensory function in patients with persistent idiopathic types of orofacial pain like atypical odontalgia (AO) is not well described. This study tested the hypothesis that AO patients have significantly more somatosensory abnormalities than age- and sex-matched controls. Forty-six AO patients and 35 controls participated. Inclusion criteria for AO were pain in a region where a tooth had been endodontically or surgically treated, persistent pain >6 months, and lack of clinical and radiological findings. The examination included qualitative tests and a battery of intraoral quantitative sensory testing (QST). Most AO patients (85%) had qualitative somatosensory abnormality compared with few controls (14%). The most common qualitative abnormalities in AO patients were found with pin-prick 67.4%, cold 47.8%, and touch 46.5% compared with 11.4%, 8.6%, and 2.9%, respectively, in the control group (P<0.001). Between-group differences were seen for many intraoral QST: mechanical detection threshold, mechanical pain threshold (pinprick), dynamic mechanical allodynia (brush), dynamic mechanical allodynia (vibration), wind-up ratio, and pressure pain threshold (P<0.01). In the trigeminal area, between-group differences in thermal thresholds were nonsignificant while differences in cold detection at the thenar eminence were significant. Individual somatosensory profiles revealed complex patterns with hyper- and hyposensitivity to intraoral QST. Between-group differences in pressure pain thresholds (P<0.02) were observed at the thenar eminence. In conclusion, significant abnormalities in intraoral somatosensory function were observed in AO, which may reflect peripheral and central sensitization of trigeminal pathways. More generalized sensitization of the nociceptive system may also be part of AO pathophysiology.

  3. Somatosensory Profiles but Not Numbers of Somatosensory Abnormalities of Neuropathic Pain Patients Correspond with Neuropathic Pain Grading

    NARCIS (Netherlands)

    Konopka, Karl-Heinz; Harbers, Marten; Houghton, Andrea; Kortekaas, Rudie; van Vliet, Andre; Timmerman, Wia; den Boer, Johan A.; Struys, Michel M. R. F.; van Wijhe, Marten

    2012-01-01

    Due to the lack of a specific diagnostic tool for neuropathic pain, a grading system to categorize pain as 'definite', 'probable', 'possible' and 'unlikely' neuropathic was proposed. Somatosensory abnormalities are common in neuropathic pain and it has been suggested that a greater number of

  4. Impact of transcranial direct current stimulation on somatosensory transfer learning: when the secondary somatosensory cortex comes into play.

    Science.gov (United States)

    Hirtz, Raphael; Weiss, Thomas; Huonker, Ralph; Witte, Otto W

    2018-04-03

    Transfer learning is an immanent feature of perceptual learning. Yet, despite the increasingly widespread application of transcranial direct current stimulation (tDCS) to study learning, transfer effects in response to tDCS have not been studied. Therefore, the present study investigated the transfer of tactile acuity evoked by repeatedly applied anodal tDCS over the left primary somatosensory cortex (S1) over the course of five days from the dominant (right) to the non-dominant (left) index finger (IF). There was a complete transfer of improvement of the right IF to its contralateral homologue by follow-up four weeks later. Changes in tactile acuity of the left IF in the tDCS anodal condition were accompanied by a significant longitudinal change in functional connectivity between the left S1 and the right secondary somatosensory cortex (S2) assessed at day five of tDCS delivery and four week later. Moreover, we observed a close link between tactile acuity and (changes of) functional connectivity of the right S2 in the tDCS anodal condition identifying the S2 as neural correlate to mediate the transfer of tDCS effects in the somatosensory domain. These findings provide unprecedented evidence of transfer effects evoked by tDCS, implicate the S2 in somatosensory transfer learning and provide evidence in support of models of perceptual learning allocating learning to the reweighting of connections between different levels of processing. Copyright © 2018. Published by Elsevier B.V.

  5. A Photographic View of Cumulative Distribution Functions

    Science.gov (United States)

    Jernigan, Robert W.

    2008-01-01

    This article shows a concrete and easy recognizable view of a cumulative distribution function(cdf). Photograph views of the search tabs on dictionaries are used to increase students' understanding and facility with the concept of a cumulative distribution function. Projects for student investigations are also given. This motivation and view helps…

  6. Cumulative Student Loan Debt in Minnesota, 2015

    Science.gov (United States)

    Williams-Wyche, Shaun

    2016-01-01

    To better understand student debt in Minnesota, the Minnesota Office of Higher Education (the Office) gathers information on cumulative student loan debt from Minnesota degree-granting institutions. These data detail the number of students with loans by institution, the cumulative student loan debt incurred at that institution, and the percentage…

  7. System-Reliability Cumulative-Binomial Program

    Science.gov (United States)

    Scheuer, Ernest M.; Bowerman, Paul N.

    1989-01-01

    Cumulative-binomial computer program, NEWTONP, one of set of three programs, calculates cumulative binomial probability distributions for arbitrary inputs. NEWTONP, CUMBIN (NPO-17555), and CROSSER (NPO-17557), used independently of one another. Program finds probability required to yield given system reliability. Used by statisticians and users of statistical procedures, test planners, designers, and numerical analysts. Program written in C.

  8. Common-Reliability Cumulative-Binomial Program

    Science.gov (United States)

    Scheuer, Ernest, M.; Bowerman, Paul N.

    1989-01-01

    Cumulative-binomial computer program, CROSSER, one of set of three programs, calculates cumulative binomial probability distributions for arbitrary inputs. CROSSER, CUMBIN (NPO-17555), and NEWTONP (NPO-17556), used independently of one another. Point of equality between reliability of system and common reliability of components found. Used by statisticians and users of statistical procedures, test planners, designers, and numerical analysts. Program written in C.

  9. Cumulative human impacts on marine predators

    DEFF Research Database (Denmark)

    Maxwell, Sara M; Hazen, Elliott L; Bograd, Steven J

    2013-01-01

    Stressors associated with human activities interact in complex ways to affect marine ecosystems, yet we lack spatially explicit assessments of cumulative impacts on ecologically and economically key components such as marine predators. Here we develop a metric of cumulative utilization and impact...

  10. Diagnosis and management of somatosensory tinnitus: review article

    Directory of Open Access Journals (Sweden)

    Tanit Ganz Sanchez

    2011-01-01

    Full Text Available Tinnitus is the perception of sound in the absence of an acoustic external stimulus. It affects 10-17% of the world's population and it a complex symptom with multiple causes, which is influenced by pathways other than the auditory one. Recently, it has been observed that tinnitus may be provoked or modulated by stimulation arising from the somatosensorial system, as well as from the somatomotor and visual-motor systems. This specific subgroup -somatosensory tinnitus - is present in 65% of cases, even though it tends to be underdiagnosed. As a consequence, it is necessary to establish evaluation protocols and specific treatments focusing on both the auditory pathway and the musculoskeletal system.

  11. Discrimination of Finger Area of Somatosensory Cortex by NIRS

    Science.gov (United States)

    Xu, Mingdi; Hayami, Takehito; Iramina, Keiji

    We carried out a near-infrared spectroscopy (NIRS) study to observe the hemodynamic responses associated with cortical activation in the primary somatosensory cortex (SI) by finger electrical stimulation. We examined whether NIRS can assist in investigating the somatotopic arrangement of fingers on the SI hand area. We found that although relatively low in spatial resolution, NIRS can to some extent help to discriminate the representations of thumb and ring finger on the SI hand area.

  12. Somatosensory Contribution to the Initial Stages of Human Motor Learning.

    Science.gov (United States)

    Bernardi, Nicolò F; Darainy, Mohammad; Ostry, David J

    2015-10-21

    The early stages of motor skill acquisition are often marked by uncertainty about the sensory and motor goals of the task, as is the case in learning to speak or learning the feel of a good tennis serve. Here we present an experimental model of this early learning process, in which targets are acquired by exploration and reinforcement rather than sensory error. We use this model to investigate the relative contribution of motor and sensory factors to human motor learning. Participants make active reaching movements or matched passive movements to an unseen target using a robot arm. We find that learning through passive movements paired with reinforcement is comparable with learning associated with active movement, both in terms of magnitude and durability, with improvements due to training still observable at a 1 week retest. Motor learning is also accompanied by changes in somatosensory perceptual acuity. No stable changes in motor performance are observed for participants that train, actively or passively, in the absence of reinforcement, or for participants who are given explicit information about target position in the absence of somatosensory experience. These findings indicate that the somatosensory system dominates learning in the early stages of motor skill acquisition. The research focuses on the initial stages of human motor learning, introducing a new experimental model that closely approximates the key features of motor learning outside of the laboratory. The finding indicates that it is the somatosensory system rather than the motor system that dominates learning in the early stages of motor skill acquisition. This is important given that most of our computational models of motor learning are based on the idea that learning is motoric in origin. This is also a valuable finding for rehabilitation of patients with limited mobility as it shows that reinforcement in conjunction with passive movement results in benefits to motor learning that are as great

  13. Vibration and muscle contraction affect somatosensory evoked potentials

    OpenAIRE

    Cohen, LG; Starr, A

    1985-01-01

    We recorded potentials evoked by specific somatosensory stimuli over peripheral nerve, spinal cord, and cerebral cortex. Vibration attenuated spinal and cerebral potentials evoked by mixed nerve and muscle spindle stimulation; in one subject that was tested, there was no effect on cutaneous input. Presynaptic inhibition of Ia input in the spinal cord and muscle spindle receptor occupancy are probably the responsible mechanisms. In contrast, muscle contraction attenuated cerebral potentials to...

  14. Quantitative methods for somatosensory evaluation in atypical odontalgia

    OpenAIRE

    PORPORATTI,André Luís; COSTA,Yuri Martins; STUGINSKI-BARBOSA,Juliana; BONJARDIM,Leonardo Rigoldi; CONTI,Paulo César Rodrigues; SVENSSON,Peter

    2015-01-01

    A systematic review was conducted to identify reliable somatosensory evaluation methods for atypical odontalgia (AO) patients. The computerized search included the main databases (MEDLINE, EMBASE, and Cochrane Library). The studies included used the following quantitative sensory testing (QST) methods: mechanical detection threshold (MDT), mechanical pain threshold (MPT) (pinprick), pressure pain threshold (PPT), dynamic mechanical allodynia with a cotton swab (DMA1) or a brush (DMA2), warm d...

  15. Thickening of the somatosensory cortex in migraine without aura.

    Science.gov (United States)

    Kim, Ji Hyun; Kim, Jung Bin; Suh, Sang-il; Seo, Woo-Keun; Oh, Kyungmi; Koh, Seong-Beom

    2014-12-01

    We aimed to explore cortical thickness abnormalities in a homogeneous group of patients with migraine without aura and to delineate possible relationships between cortical thickness changes and clinical variables. Fifty-six female migraine patients without aura and T2-visible white matter hyperintensities and 34 female controls were scanned on a 3T magnetic resonance imager. Cortical thickness was estimated and compared between patients and controls using a whole-brain vertex-by-vertex analysis. Correlation analysis was conducted between cortical thickness of significant clusters and clinical variables. Compared to controls, migraine patients had cortical thickening in left rostral middle frontal gyrus and bilateral post-central gyri. Region-of-interest analysis revealed cortical thickening of bilateral post-central gyri in migraine patients relative to controls. The average thickness of bilateral post-central gyri positively correlated with disease duration as well as estimated lifetime headache frequency. We have provided evidence for interictal cortical abnormalities of thickened prefrontal cortex and somatosensory cortex in female migraine patients without aura. Our findings of greater thickening of the somatosensory cortex in relation to increasing disease duration and increasing headache frequency suggest that repeated migraine attacks over time may lead to structural changes of the somatosensory cortex through increased noxious afferent input within the trigemino-thalamo-cortical pathway in migraine. © International Headache Society 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  16. Four-dimensional maps of the human somatosensory system.

    Science.gov (United States)

    Avanzini, Pietro; Abdollahi, Rouhollah O; Sartori, Ivana; Caruana, Fausto; Pelliccia, Veronica; Casaceli, Giuseppe; Mai, Roberto; Lo Russo, Giorgio; Rizzolatti, Giacomo; Orban, Guy A

    2016-03-29

    A fine-grained description of the spatiotemporal dynamics of human brain activity is a major goal of neuroscientific research. Limitations in spatial and temporal resolution of available noninvasive recording and imaging techniques have hindered so far the acquisition of precise, comprehensive four-dimensional maps of human neural activity. The present study combines anatomical and functional data from intracerebral recordings of nearly 100 patients, to generate highly resolved four-dimensional maps of human cortical processing of nonpainful somatosensory stimuli. These maps indicate that the human somatosensory system devoted to the hand encompasses a widespread network covering more than 10% of the cortical surface of both hemispheres. This network includes phasic components, centered on primary somatosensory cortex and neighboring motor, premotor, and inferior parietal regions, and tonic components, centered on opercular and insular areas, and involving human parietal rostroventral area and ventral medial-superior-temporal area. The technique described opens new avenues for investigating the neural basis of all levels of cortical processing in humans.

  17. Somatosensory mismatch response in young and elderly adults

    Directory of Open Access Journals (Sweden)

    Juho M. Strömmer

    2014-10-01

    Full Text Available Aging is associated with cognitive decline and alterations in early perceptual processes. Studies in the auditory and visual modalities have shown that the mismatch negativity (or the mismatch response, MMR, an event-related potential (ERP elicited by a deviant stimulus in a background of homogenous events, diminishes with aging and cognitive decline. However, the effects of aging on the somatosensory MMR are not known. In the current study, we recorded ERPs to electrical pulses to different fingers of the left hand in a passive oddball experiment in young (22–36 years and elderly (66–95 years adults engaged in a visual task. The MMR was found to deviants as compared to standards at two latency ranges: 180–220 ms and 250–290 ms post-stimulus onset. At 180–220 ms, within the young, the MMR was found at medial electrode sites, whereas aged did not show any amplitude difference between the stimulus types at the same latency range. At 250–290 ms, the MMR was evident with attenuated amplitude and narrowed scalp distribution among aged (Fz compared to young (fronto-centrally and lateral parietal sites. Hence, the results reveal that the somatosensory change detection mechanism is altered in aging. The somatosensory MMR can be used as a reliable measure of age-related changes in sensory-cognitive functions.

  18. Airway somatosensory deficits and dysphagia in Parkinson's disease.

    Science.gov (United States)

    Hammer, Michael J; Murphy, Caitlin A; Abrams, Trisha M

    2013-01-01

    Individuals with Parkinson's disease (PD) often experience substantial impairment of swallow control, and are typically unaware of the presence or severity of their impairments suggesting that these individuals may also experience airway sensory deficits. However, the degree to which impaired swallow function in PD may relate to airway sensory deficits has yet to be formally tested. The purpose of this study was to examine whether airway sensory function is associated with swallow impairment in PD. Eighteen PD participants and 18 healthy controls participated in this study and underwent endoscopic assessment of airway somatosensory function, endoscopic assessment of swallow function, and clinical ratings of swallow and disease severity. PD participants exhibited abnormal airway somatosensory function and greater swallow impairment compared with healthy controls. Swallow and sensory deficits in PD were correlated with disease severity. Moreover, PD participants reported similar self-rated swallow function as healthy controls, and swallow deficits were correlated with sensory function suggesting an association between impaired sensory function and poor self-awareness of swallow deficits in PD. These results suggest that control of swallow is influenced by airway somatosensory function, that swallow-related deficits in PD are related to abnormal somatosensation, and that swallow and airway sensory function may degrade as a function of disease severity. Therefore, the basal ganglia and related neural networks may play an important role to integrate airway sensory input for swallow-related motor control. Furthermore, the airway deficits observed in PD suggest a disintegration of swallow-related sensory and motor control.

  19. Reward facilitates tactile judgments and modulates hemodynamic responses in human primary somatosensory cortex

    OpenAIRE

    Pleger, B; Blankenburg, F; Ruff, Christian C; Driver, J; Dolan, R J

    2008-01-01

    Reinforcing effects of reward on action are well established, but possible effects on sensory function are less well explored. Here, using functional magnetic resonance imaging, we assessed whether reward can influence somatosensory judgments and modulate activity in human somatosensory cortex. Participants discriminated electrical somatosensory stimuli on an index finger with correct performance rewarded financially at trial end, at one of four different anticipated levels. Higher rewards im...

  20. The effect of anodal transcranial direct current stimulation over the primary motor or somatosensory cortices on somatosensory evoked magnetic fields.

    Science.gov (United States)

    Sugawara, Kazuhiro; Onishi, Hideaki; Yamashiro, Koya; Kojima, Sho; Miyaguchi, Shota; Kirimoto, Hikari; Tsubaki, Atsuhiro; Tamaki, Hiroyuki; Shirozu, Hiroshi; Kameyama, Shigeki

    2015-01-01

    The purpose of this study was to investigate the effect of anodal transcranial direct-current stimulation (tDCS) applied over the primary motor (M1) or the primary somatosensory (S1) cortices on somatosensory evoked magnetic fields (SEFs) following median nerve stimulation. Anodal tDCS was applied for 15min on the left motor or somatosensory cortices at 1mA. SEFs were recorded following right median nerve stimulation using a magnetoencephalography (MEG) system before and after the application of tDCS. SEFs was measured and compared before and after tDCS was applied over M1 or S1. The source strengths for the P35m and P60m increased after tDCS was applied over M1 and that for the P60m increased after tDCS was applied over S1. The mean equivalent current dipole (ECD) location for the P35m was located significantly anterior to that of the N20m, but only during post 1 (10-20min after tDCS was applied over M1). Our results indicated that the anodal tDCS applied over M1 affected the P35m and P60m sources on SEF components, while that applied over S1 influenced the P60m source. We demonstrated anodal tDCS applied over M1 or S1 can modulate somatosensory processing and components of SEFs, confirming the hypothesis for locally distinct generators of the P35m and P60m sources. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  1. SOMATOSENSORY EVOKED POTENTIALS IN DIABETES MELLITUS TYPE - 2

    Directory of Open Access Journals (Sweden)

    Rekha

    2015-10-01

    Full Text Available Diabetes mellitus is the most common metabolic disorder affecting majority of population. It is estimated that over 400 million people throughout the world have diabetes. It has progressed to be a pandemic from an epidemic causing morbidity and mortality in the population. Among the many complications of diabetes, diabetic neuropathies contribute majorly to the morbidity associated with the disease. Axonal conduction is affected by elevated levels of protein kinase c causing neuronal ischemia; decreased ce llular myoinositol affecting sodium potassium ATPase pump leads to decreased nerve conduction; Somatosensory E voked P otentials (SSEPs reflect the activity of somatosensory pathways mediated through the dorsal columns of the spinal cord and the specific so matosensory cortex. Recording of Somatosensory Evoked Potentials in diabetics is done to assess the sensory involvement of spinal cord. Presence of SEPs provides clear evidence for axonal continuity and by using different stimulation sites, the rate of reg eneration can be determined. Both onset and peak latencies of all SEP components are prolonged in patients with diabetes. Present study is done to compare somatosensory evoked potentials in diabetics and normal subjects. MATERIALS AND METHOD S: The present study was undertaken at the Upgraded Department of Physiology, Osmania Medical College, Koti, Hyderabad. The study was conducted on subjects, both male and female in the age group of 45 to 55 years, suffering from type II diabetes excluding other neurologi cal disorders. Non - invasive method of estimation of nerve conduction studies using SFEMG/EP — Electromyography or evoked potential system (Nicolet systems — USA using surface electrodes with automated computerized monitor attached with printer is used. RESUL TS : ANOVA showed statistically significant N9 latency (right & left sides. Latencies of all the components of SSEPs were more significant than amplitudes in Diabetic

  2. A New Animal Model for Developing a Somatosensory Neural Interface for Prosthetic Limbs

    National Research Council Canada - National Science Library

    Weber, Douglas J

    2008-01-01

    ...). To the effectiveness of afferent microstimulation, we recorded evoked neural activity in the somatosensory cortex during microstimulation with patterns that varied in 1) amplitude (stimulus current), 2) location...

  3. Age-dependent modulation of the somatosensory network upon eye closure.

    Science.gov (United States)

    Brodoehl, Stefan; Klingner, Carsten; Witte, Otto W

    2016-02-01

    Eye closure even in complete darkness can improve somatosensory perception by switching the brain to a uni-sensory processing mode. This causes an increased information flow between the thalamus and the somatosensory cortex while decreasing modulation by the visual cortex. Previous work suggests that these modulations are age-dependent and that the benefit in somatosensory performance due to eye closing diminishes with age. The cause of this age-dependency and to what extent somatosensory processing is involved remains unclear. Therefore, we intended to characterize the underlying age-dependent modifications in the interaction and connectivity of different sensory networks caused by eye closure. We performed functional MR-imaging with tactile stimulation of the right hand under the conditions of opened and closed eyes in healthy young and elderly participants. Conditional Granger causality analysis was performed to assess the somatosensory and visual networks, including the thalamus. Independent of age, eye closure improved the information transfer from the thalamus to and within the somatosensory cortex. However, beyond that, we found an age-dependent recruitment strategy. Whereas young participants were characterized by an optimized information flow within the relays of the somatosensory network, elderly participants revealed a stronger modulatory influence of the visual network upon the somatosensory cortex. Our results demonstrate that the modulation of the somatosensory and visual networks by eye closure diminishes with age and that the dominance of the visual system is more pronounced in the aging brain. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Cumulative cultural learning: Development and diversity.

    Science.gov (United States)

    Legare, Cristine H

    2017-07-24

    The complexity and variability of human culture is unmatched by any other species. Humans live in culturally constructed niches filled with artifacts, skills, beliefs, and practices that have been inherited, accumulated, and modified over generations. A causal account of the complexity of human culture must explain its distinguishing characteristics: It is cumulative and highly variable within and across populations. I propose that the psychological adaptations supporting cumulative cultural transmission are universal but are sufficiently flexible to support the acquisition of highly variable behavioral repertoires. This paper describes variation in the transmission practices (teaching) and acquisition strategies (imitation) that support cumulative cultural learning in childhood. Examining flexibility and variation in caregiver socialization and children's learning extends our understanding of evolution in living systems by providing insight into the psychological foundations of cumulative cultural transmission-the cornerstone of human cultural diversity.

  5. About the cumulants of periodic signals

    Science.gov (United States)

    Barrau, Axel; El Badaoui, Mohammed

    2018-01-01

    This note studies cumulants of time series. These functions originating from the probability theory being commonly used as features of deterministic signals, their classical properties are examined in this modified framework. We show additivity of cumulants, ensured in the case of independent random variables, requires here a different hypothesis. Practical applications are proposed, in particular an analysis of the failure of the JADE algorithm to separate some specific periodic signals.

  6. Calculating Cumulative Binomial-Distribution Probabilities

    Science.gov (United States)

    Scheuer, Ernest M.; Bowerman, Paul N.

    1989-01-01

    Cumulative-binomial computer program, CUMBIN, one of set of three programs, calculates cumulative binomial probability distributions for arbitrary inputs. CUMBIN, NEWTONP (NPO-17556), and CROSSER (NPO-17557), used independently of one another. Reliabilities and availabilities of k-out-of-n systems analyzed. Used by statisticians and users of statistical procedures, test planners, designers, and numerical analysts. Used for calculations of reliability and availability. Program written in C.

  7. Origin of path independence between cumulative CO2 emissions and global warming

    Science.gov (United States)

    Seshadri, Ashwin K.

    2017-11-01

    Observations and GCMs exhibit approximate proportionality between cumulative carbon dioxide (CO2) emissions and global warming. Here we identify sufficient conditions for the relationship between cumulative CO2 emissions and global warming to be independent of the path of CO2 emissions; referred to as "path independence". Our starting point is a closed form expression for global warming in a two-box energy balance model (EBM), which depends explicitly on cumulative emissions, airborne fraction and time. Path independence requires that this function can be approximated as depending on cumulative emissions alone. We show that path independence arises from weak constraints, occurring if the timescale for changes in cumulative emissions (equal to ratio between cumulative emissions and emissions rate) is small compared to the timescale for changes in airborne fraction (which depends on CO2 uptake), and also small relative to a derived climate model parameter called the damping-timescale, which is related to the rate at which deep-ocean warming affects global warming. Effects of uncertainties in the climate model and carbon cycle are examined. Large deep-ocean heat capacity in the Earth system is not necessary for path independence, which appears resilient to climate modeling uncertainties. However long time-constants in the Earth system carbon cycle are essential, ensuring that airborne fraction changes slowly with timescale much longer than the timescale for changes in cumulative emissions. Therefore path independence between cumulative emissions and warming cannot arise for short-lived greenhouse gases.

  8. Cumulative effects assessment: Does scale matter?

    International Nuclear Information System (INIS)

    Therivel, Riki; Ross, Bill

    2007-01-01

    Cumulative effects assessment (CEA) is (or should be) an integral part of environmental assessment at both the project and the more strategic level. CEA helps to link the different scales of environmental assessment in that it focuses on how a given receptor is affected by the totality of plans, projects and activities, rather than on the effects of a particular plan or project. This article reviews how CEAs consider, and could consider, scale issues: spatial extent, level of detail, and temporal issues. It is based on an analysis of Canadian project-level CEAs and UK strategic-level CEAs. Based on a review of literature and, especially, case studies with which the authors are familiar, it concludes that scale issues are poorly considered at both levels, with particular problems being unclear or non-existing cumulative effects scoping methodologies; poor consideration of past or likely future human activities beyond the plan or project in question; attempts to apportion 'blame' for cumulative effects; and, at the plan level, limited management of cumulative effects caused particularly by the absence of consent regimes. Scale issues are important in most of these problems. However both strategic-level and project-level CEA have much potential for managing cumulative effects through better siting and phasing of development, demand reduction and other behavioural changes, and particularly through setting development consent rules for projects. The lack of strategic resource-based thresholds constrains the robust management of strategic-level cumulative effects

  9. Cumulative cultural evolution: the role of teaching.

    Science.gov (United States)

    Castro, Laureano; Toro, Miguel A

    2014-04-21

    In humans, cultural transmission occurs usually by cumulative inheritance, generating complex adaptive behavioral features. Cumulative culture requires key psychological processes (fundamentally imitation and teaching) that are absent or impoverished in non-human primates. In this paper we analyze the role that teaching has played in human cumulative cultural evolution. We assume that a system of cumulative culture generates increasingly adaptive behaviors, that are also more complex and difficult to imitate. Our thesis is that, as cultural traits become more complex, cumulative cultural transmission requires teaching to ensure accurate transmission from one generation to the next. In an increasingly complex cultural environment, we consider that individuals commit errors in imitation. We develop a model of cumulative cultural evolution in a changing environment and show that these errors hamper the process of cultural accumulation. We also show that a system of teaching between parents and offspring that increases the fidelity of imitation unblocks the accumulation and becomes adaptive whenever the gain in fitness compensates the cost of teaching. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Single-trial detection for intraoperative somatosensory evoked potentials monitoring.

    Science.gov (United States)

    Hu, L; Zhang, Z G; Liu, H T; Luk, K D K; Hu, Y

    2015-12-01

    Abnormalities of somatosensory evoked potentials (SEPs) provide effective evidence for impairment of the somatosensory system, so that SEPs have been widely used in both clinical diagnosis and intraoperative neurophysiological monitoring. However, due to their low signal-to-noise ratio (SNR), SEPs are generally measured using ensemble averaging across hundreds of trials, thus unavoidably producing a tardiness of SEPs to the potential damages caused by surgical maneuvers and a loss of dynamical information of cortical processing related to somatosensory inputs. Here, we aimed to enhance the SNR of single-trial SEPs using Kalman filtering and time-frequency multiple linear regression (TF-MLR) and measure their single-trial parameters, both in the time domain and in the time-frequency domain. We first showed that, Kalman filtering and TF-MLR can effectively capture the single-trial SEP responses and provide accurate estimates of single-trial SEP parameters in the time domain and time-frequency domain, respectively. Furthermore, we identified significant correlations between the stimulus intensity and a set of indicative single-trial SEP parameters, including the correlation coefficient (between each single-trial SEPs and their average), P37 amplitude, N45 amplitude, P37-N45 amplitude, and phase value (at the zero-crossing points between P37 and N45). Finally, based on each indicative single-trial SEP parameter, we investigated the minimum number of trials required on a single-trial basis to suggest the existence of SEP responses, thus providing important information for fast SEP extraction in intraoperative monitoring.

  11. A BCI System Based on Somatosensory Attentional Orientation.

    Science.gov (United States)

    Yao, Lin; Sheng, Xinjun; Zhang, Dingguo; Jiang, Ning; Farina, Dario; Zhu, Xiangyang

    2017-01-01

    We propose and test a novel brain-computer interface (BCI) based on imagined tactile sensation. During an imagined tactile sensation, referred to as somatosensory attentional orientation (SAO), the subject shifts and maintains somatosensory attention on a body part, e.g., left or right hand. The SAO can be detected from EEG recordings for establishing a communication channel. To test for the hypothesis that SAO on different body parts can be discriminated from EEG, 14 subjects were assigned to a group who received an actual sensory stimulation (STE-Group), and 18 subjects were assigned to the SAO only group (SAO-Group). In single trials, the STE-Group received tactile stimulation first (both wrists simultaneously stimulated), and then maintained the attention on the selected body part (without stimulation). The same group also performed the SAO task first and then received the tactile stimulation. Conversely, the SAO-Group performed SAO without any stimulation, neither before nor after the SAO. In both the STE-Group and SAO-Group, it was possible to identify the SAO-related oscillatory activation that corresponded to a contralateral event-related desynchronization (ERD) stronger than the ipsilateral ERD. Discriminative information, represented as R 2 , was found mainly on the somatosensory area of the cortex. In the STE-Group, the average classification accuracy of SAO was 83.6%, and it was comparable with tactile BCI based on selective sensation (paired-t test, P > 0.05 ). In the SAO-Group the average online performance was 75.7%. For this group, after frequency band selection the offline performance reached 82.5% on average, with ≥ 80% for 12 subjects and ≥ 95% for four subjects. Complementary to tactile sensation, the SAO does not require sensory stimulation, with the advantage of being completely independent from the stimulus.

  12. Idiopathic restless legs syndrome: abnormalities in central somatosensory processing.

    Science.gov (United States)

    Schattschneider, Jörn; Bode, Andre; Wasner, Gunnar; Binder, Andreas; Deuschl, Günther; Baron, Ralf

    2004-08-01

    Neurophysiological studies have shown an impairment of temperature perception in secondary and idiopathic restless legs syndrome (RLS). It is unclear whether these deficits are caused by peripheral nerve fibre damage or by central impairment of somatosensory processing. The aim of the present study was (1) to determine the frequency of thermal hypaesthesia in a large population of secondary and idiopathic RLS patients; (2) to differentiate between a peripheral and central disturbance of somatosensory processing and (3) to correlate these findings with the clinical manifestation of the disease. From the results of clinical examination, nerve conduction studies and blood samples the patients were divided into secondary and idiopathic RLS groups. The severity of RLS symptoms was assessed by standardized questionnaires. Quantitative sensory testing (QST) assessing temperature perception was performed in all patients. The peripheral function of small nerve fibres was evaluated by the quantitative nociceptor axon reflex test (QNART). 22 secondary and 20 idiopathic RLS patients participated in the study. Impairment of temperature perception (QST) was found in 72% of the secondary RLS patients and in 55% of idiopathic RLS patients. The peripheral C-fibre function (QNART) was normal in idiopathic RLS patients. In contrast it was significantly impaired in secondary RLS patients compared with idiopathic RLS patients and age matched controls. There was no correlation between the results obtained in QST and clinical scores. Impairment of temperature perception is present in a high percentage of RLS patients. In secondary RLS the sensory deficits are at least in part caused by small fibre neuropathy. In idiopathic RLS a functional impairment of central somatosensory processing is present.

  13. Brain motor functional changes after somatosensory discrimination training.

    Science.gov (United States)

    Sarasso, Elisabetta; Agosta, Federica; Temporiti, Federico; Adamo, Paola; Piccolo, Fabio; Copetti, Massimiliano; Gatti, Roberto; Filippi, Massimo

    2017-08-31

    Somatosensory discrimination training may modulate cognitive processes, such as movement planning and monitoring, which can be useful during active movements. The aim of the study was to assess the effect of somatosensory discrimination training on brain functional activity using functional magnetic resonance imaging (fMRI) during motor and sensory tasks in healthy subjects. Thirty-nine healthy young subjects were randomized into two groups: the experimental group underwent somatosensory discrimination training consisting of shape, surface and two-point distance discrimination; and the control group performed a simple object manipulation. At baseline and after 2 weeks of training, subjects underwent sensorimotor evaluations and fMRI tasks consisting of right-hand tactile stimulation, manipulation of a simple object, and complex right-hand motor sequence execution. Right-hand dexterity improved in both groups, but only the experimental group showed improvements in all manual dexterity tests. After training, the experimental group showed: decreased activation of the ipsilateral sensorimotor areas during the tactile stimulation task; increased activation of the contralateral postcentral gyrus and thalamus bilaterally during the manipulation task; and a reduced recruitment of the ipsilateral pre/postcentral gyri and an increased activation of the basal ganglia and cerebellum contralaterally during the complex right-hand motor task. In healthy subjects, sensory discrimination training was associated with lateralization of brain activity in sensorimotor areas during sensory and motor tasks. Further studies are needed to investigate the usefulness of this training in motor rehabilitation of patients with focal lesions in the central nervous system.

  14. Multilevel cortical processing of somatosensory novelty: a magnetoencephalography study

    Directory of Open Access Journals (Sweden)

    Gilles eNaeije

    2016-06-01

    Full Text Available Using magnetoencephalography (MEG, this study investigates the spatio-temporal dynamics of the multilevel cortical processing of somatosensory change detection. Neuromagnetic signals of sixteen healthy adult subjects (7 females and 9 males, mean age 29 +/-3 y were recorded using whole-scalp-covering MEG while they underwent an oddball paradigm based on simple standard (right index fingertip tactile stimulation and deviant (simultaneous right index fingertip and middle phalanx tactile stimulation stimuli gathered into sequences to create and then deviate from stimulus patterns at multiple (local versus global levels of complexity. Five healthy adult subjects (3 females and 2 males, mean age 31,6 +/-2 y also underwent a similar oddball paradigm in which standard and deviant stimuli were flipped.Local deviations led to a somatosensory mismatch response peaking at 55-130 ms post-stimulus onset with a cortical generator located at the contralateral secondary somatosensory cortex. The mismatch response was independent of the deviant stimuli physical characteristics. Global deviants led to a P300 response with cortical sources located bilaterally at temporo-parietal junction (TPJ and supplementary motor area (SMA. The posterior parietal cortex (PPC and the SMA were found to generate a contingent magnetic variation (CMV attributed to top-down expectations. Amplitude of mismatch responses were modulated by top-down expectations and correlated with both the magnitude of the CMV and the P300 amplitude at the right TPJ. These results provide novel empirical evidence for a unified sensory novelty detection system in the human brain by linking detection of salient sensory stimuli in personal and extra-personal spaces to a common framework of multilevel cortical processing.

  15. Multilevel Cortical Processing of Somatosensory Novelty: A Magnetoencephalography Study.

    Science.gov (United States)

    Naeije, Gilles; Vaulet, Thibaut; Wens, Vincent; Marty, Brice; Goldman, Serge; De Tiège, Xavier

    2016-01-01

    Using magnetoencephalography (MEG), this study investigates the spatio-temporal dynamics of the multilevel cortical processing of somatosensory change detection. Neuromagnetic signals of 16 healthy adult subjects (7 females and 9 males, mean age 29 ± 3 years) were recorded using whole-scalp-covering MEG while they underwent an oddball paradigm based on simple standard (right index fingertip tactile stimulation) and deviant (simultaneous right index fingertip and middle phalanx tactile stimulation) stimuli gathered into sequences to create and then deviate from stimulus patterns at multiple (local vs. global) levels of complexity. Five healthy adult subjects (3 females and 2 males, mean age 31, 6 ± 2 years) also underwent a similar oddball paradigm in which standard and deviant stimuli were flipped. Local deviations led to a somatosensory mismatch response peaking at 55-130 ms post-stimulus onset with a cortical generator located at the contralateral secondary somatosensory (cSII) cortex. The mismatch response was independent of the deviant stimuli physical characteristics. Global deviants led to a P300 response with cortical sources located bilaterally at temporo-parietal junction (TPJ) and supplementary motor area (SMA). The posterior parietal cortex (PPC) and the SMA were found to generate a contingent magnetic variation (CMV) attributed to top-down expectations. Amplitude of mismatch responses were modulated by top-down expectations and correlated with both the magnitude of the CMV and the P300 amplitude at the right TPJ. These results provide novel empirical evidence for a unified sensory novelty detection system in the human brain by linking detection of salient sensory stimuli in personal and extra-personal spaces to a common framework of multilevel cortical processing.

  16. On weighted cumulative residual Tsallis entropy and its dynamic version

    Science.gov (United States)

    Khammar, A. H.; Jahanshahi, S. M. A.

    2018-02-01

    Recently, Sati and Gupta (2015) have introduced a generalized cumulative residual entropy based on the non-additive Tsallis entropy. The cumulative residual entropy, introduced by Rao et al. (2004) is a generalized measure of uncertainty which is applied in reliability and image alignment and non-additive measures of entropy. This entropy finds justifications in many physical, biological and chemical phenomena. In this paper, we derive the weighted form of this measure and call it Weighted Cumulative Residual Tsallis Entropy (WCRTE). Being a "length-biased" shift-dependent information measure, WCRTE is related to the differential information in which higher weight is assigned to large values of observed random variables. Based on the dynamic version of this new information measure, we propose ageing classes and it is shown that it can uniquely determine the survival function and Rayleigh distribution. Several properties, including linear transformations, bounds and related results to stochastic orders are obtained for these measures. Also, we identify classes of distributions in which some well-known distributions are maximum dynamic version of WCRTE. The empirical WCRTE is finally proposed to estimate the new information measure.

  17. An evaluation of the somatosensory profile of hemiparetic individuals

    Directory of Open Access Journals (Sweden)

    R.S. Mota

    2010-01-01

    Full Text Available The purpose of this study was to evaluate the somatosensory profile of 18 hemiparetic spastic victims of stroke with and without blocking vision. Maximal isometric contraction test was used for flexor and extensor muscles of the hip and knee, and flexor plantar muscles. The number of cycles per minute on stationary bike was also measured with eyes opened and closed. Significant differences were found suggesting the existence of miscommunication between sensory-motor neural mechanisms responsible for voluntary motor actions in these individuals.

  18. Pulsed ultrasound differentially stimulates somatosensory circuits in humans as indicated by EEG and FMRI.

    Directory of Open Access Journals (Sweden)

    Wynn Legon

    Full Text Available Peripheral somatosensory circuits are known to respond to diverse stimulus modalities. The energy modalities capable of eliciting somatosensory responses traditionally belong to mechanical, thermal, electromagnetic, and photonic domains. Ultrasound (US applied to the periphery has also been reported to evoke diverse somatosensations. These observations however have been based primarily on subjective reports and lack neurophysiological descriptions. To investigate the effects of peripherally applied US on human somatosensory brain circuit activity we recorded evoked potentials using electroencephalography and conducted functional magnetic resonance imaging of blood oxygen level-dependent (BOLD responses to fingertip stimulation with pulsed US. We found a pulsed US waveform designed to elicit a mild vibration sensation reliably triggered evoked potentials having distinct waveform morphologies including a large double-peaked vertex potential. Fingertip stimulation with this pulsed US waveform also led to the appearance of BOLD signals in brain regions responsible for somatosensory discrimination including the primary somatosensory cortex and parietal operculum, as well as brain regions involved in hierarchical somatosensory processing, such as the insula, anterior middle cingulate cortex, and supramarginal gyrus. By changing the energy profile of the pulsed US stimulus waveform we observed pulsed US can differentially activate somatosensory circuits and alter subjective reports that are concomitant with changes in evoked potential morphology and BOLD response patterns. Based on these observations we conclude pulsed US can functionally stimulate different somatosensory fibers and receptors, which may permit new approaches to the study and diagnosis of peripheral nerve injury, dysfunction, and disease.

  19. Structural and functional changes in the somatosensory cortex in euthymic females with bipolar disorder.

    Science.gov (United States)

    Minuzzi, Luciano; Syan, Sabrina K; Smith, Mara; Hall, Alexander; Hall, Geoffrey Bc; Frey, Benicio N

    2017-12-01

    Current evidence from neuroimaging data suggests possible dysfunction of the fronto-striatal-limbic circuits in individuals with bipolar disorder. Somatosensory cortical function has been implicated in emotional recognition, risk-taking and affective responses through sensory modalities. This study investigates anatomy and function of the somatosensory cortex in euthymic bipolar women. In total, 68 right-handed euthymic women (bipolar disorder = 32 and healthy controls = 36) between 16 and 45 years of age underwent high-resolution anatomical and functional magnetic resonance imaging during the mid-follicular menstrual phase. The somatosensory cortex was used as a seed region for resting-state functional connectivity analysis. Voxel-based morphometry was used to evaluate somatosensory cortical gray matter volume between groups. We found increased resting-state functional connectivity between the somatosensory cortex and insular cortex, inferior prefrontal gyrus and frontal orbital cortex in euthymic bipolar disorder subjects compared to healthy controls. Voxel-based morphometry analysis showed decreased gray matter in the left somatosensory cortex in the bipolar disorder group. Whole-brain voxel-based morphometry analysis controlled by age did not reveal any additional significant difference between groups. This study is the first to date to evaluate anatomy and function of the somatosensory cortex in a well-characterized sample of euthymic bipolar disorder females. Anatomical and functional changes in the somatosensory cortex in this population might contribute to the pathophysiology of bipolar disorder.

  20. Somatosensory evoked potentials and dynamic postural assessment in adolescent idiopathic scoliosis

    Directory of Open Access Journals (Sweden)

    Dalia Mohamed Ezz El Mikkawy

    2016-01-01

    Conclusion The study demonstrates abnormal somatosensory and postural function in patients with AIS, and a significant inter-relationship between the scoliotic angle, the somatosensory system, and posture. Thus, optimum assessment and treatment of neurological pathway and balance are important in these patients.

  1. Predicting Cumulative Incidence Probability: Marginal and Cause-Specific Modelling

    DEFF Research Database (Denmark)

    Scheike, Thomas H.; Zhang, Mei-Jie

    2005-01-01

    cumulative incidence probability; cause-specific hazards; subdistribution hazard; binomial modelling......cumulative incidence probability; cause-specific hazards; subdistribution hazard; binomial modelling...

  2. Predicting Cumulative Incidence Probability by Direct Binomial Regression

    DEFF Research Database (Denmark)

    Scheike, Thomas H.; Zhang, Mei-Jie

    Binomial modelling; cumulative incidence probability; cause-specific hazards; subdistribution hazard......Binomial modelling; cumulative incidence probability; cause-specific hazards; subdistribution hazard...

  3. Intraoral somatosensory abnormalities in patients with atypical odontalgia – a controlled multicenter quantitative sensory testing study

    Science.gov (United States)

    Baad-Hansen, Lene; Pigg, Maria; Ivanovic, Susanne El’Masry; Faris, Hanan; List, Thomas; Drangsholt, Mark; Svensson, Peter

    2013-01-01

    Intraoral somatosensory sensitivity in patients with atypical odontalgia (AO) has not been investigated systematically according to the most recent guidelines. The aims of this study were to: 1. Examine intraoral somatosensory disturbances in AO patients using healthy subjects as reference and 2. Evaluate the percent agreement between intraoral quantitative sensory testing (QST) and qualitative sensory testing (QualST). Forty-seven AO patients and 69 healthy controls were included at Universities of Washington, Malmö and Aarhus. In AO patients, intraoral somatosensory testing was performed on the painful site, the corresponding contralateral site and at thenar. In healthy subjects, intraoral somatosensory testing was performed bilaterally on the upper premolar gingiva and at thenar. Thirteen QST and 3 QualST parameters were evaluated at each site, z-scores were computed for AO patients based on the healthy reference material and LossGain scores were created. 87.3% of AO patients had QST abnormalities compared with controls. The most frequent somatosensory abnormalities in AO patients were somatosensory gain with regard to painful mechanical and cold stimuli and somatosensory loss with regard to cold detection and mechanical detection. The most frequent LossGain code was L0G2 (no somatosensory loss with gain of mechanical somatosensory function)(31.9% of AO patients). Percent agreement between corresponding QST and QualST measures of thermal and mechanical sensitivity ranged between 55.6 and 70.4% in AO patients and between 71.1 and 92.1% in controls. In conclusion, intraoral somatosensory abnormalities were commonly detected in AO patients and agreement between quantitative and qualitative sensory testing was good to excellent. PMID:23725780

  4. Intraoral somatosensory abnormalities in patients with atypical odontalgia--a controlled multicenter quantitative sensory testing study.

    Science.gov (United States)

    Baad-Hansen, Lene; Pigg, Maria; Ivanovic, Susanne Eímasry; Faris, Hanan; List, Thomas; Drangsholt, Mark; Svensson, Peter

    2013-08-01

    Intraoral somatosensory sensitivity in patients with atypical odontalgia (AO) has not been investigated systematically according to the most recent guidelines. The aims of this study were to examine intraoral somatosensory disturbances in AO patients using healthy subjects as reference, and to evaluate the percent agreement between intraoral quantitative sensory testing (QST) and qualitative sensory testing (QualST). Forty-seven AO patients and 69 healthy control subjects were included at Universities of Washington, Malmö, and Aarhus. In AO patients, intraoral somatosensory testing was performed on the painful site, the corresponding contralateral site, and at thenar. In healthy subjects, intraoral somatosensory testing was performed bilaterally on the upper premolar gingiva and at thenar. Thirteen QST and 3 QualST parameters were evaluated at each site, z-scores were computed for AO patients based on the healthy reference material, and LossGain scores were created. Compared with control subjects, 87.3% of AO patients had QST abnormalities. The most frequent somatosensory abnormalities in AO patients were somatosensory gain with regard to painful mechanical and cold stimuli and somatosensory loss with regard to cold detection and mechanical detection. The most frequent LossGain code was L0G2 (no somatosensory loss with gain of mechanical somatosensory function) (31.9% of AO patients). Percent agreement between corresponding QST and QualST measures of thermal and mechanical sensitivity ranged between 55.6% and 70.4% in AO patients and between 71.1% and 92.1% in control subjects. In conclusion, intraoral somatosensory abnormalities were commonly detected in AO patients, and agreement between quantitative and qualitative sensory testing was good to excellent. Copyright © 2013 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  5. Perspectives on cumulative risks and impacts.

    Science.gov (United States)

    Faust, John B

    2010-01-01

    Cumulative risks and impacts have taken on different meanings in different regulatory and programmatic contexts at federal and state government levels. Traditional risk assessment methodologies, with considerable limitations, can provide a framework for the evaluation of cumulative risks from chemicals. Under an environmental justice program in California, cumulative impacts are defined to include exposures, public health effects, or environmental effects in a geographic area from the emission or discharge of environmental pollution from all sources, through all media. Furthermore, the evaluation of these effects should take into account sensitive populations and socioeconomic factors where possible and to the extent data are available. Key aspects to this potential approach include the consideration of exposures (versus risk), socioeconomic factors, the geographic or community-level assessment scale, and the inclusion of not only health effects but also environmental effects as contributors to impact. Assessments of this type extend the boundaries of the types of information that toxicologists generally provide for risk management decisions.

  6. Neuroanatomical correlates and somatosensorial disturbances in body dysmorphic disorder.

    Science.gov (United States)

    Yaryura-Tobias, Jose A; Neziroglu, Fugen; Torres-Gallegos, Melissa

    2002-06-01

    Body dysmorphic disorder (BDD) is a condition characterized by an intense preoccupation with an imagined or slight defect in physical appearance. Although there is a general consensus that psychosocial factors play a major role in the development of BDD, there is some evidence suggesting that an organic somatosensorial disturbance may also exist in this condition. Several psychiatric and neurological disorders, including the interparietal syndrome, Gertsman's syndrome, inferoparietal syndrome, phantom limb syndrome, genital retraction syndrome, panencephalitis, cerebrovascular syndromes, and pharyngeal streptococcia affecting the basal ganglia, can present with somatosensorial disturbances similar to BDD. The cerebral pathology in all these disorders appears to be localized in the parietal-occipital region, indicating that cerebral involvement may also be associated with BDD. An interdependence exists between cerebral regions through integrated neural networks that enable efficient processing of information. Disturbances in these association pathways can lead to an imbalance in the extensive cerebral loops. Therefore, it is possible that a defect in information-processing may play a role in the pathogenesis of BDD.

  7. Decoding Visual Object Categories in Early Somatosensory Cortex

    Science.gov (United States)

    Smith, Fraser W.; Goodale, Melvyn A.

    2015-01-01

    Neurons, even in the earliest sensory areas of cortex, are subject to a great deal of contextual influence from both within and across modality connections. In the present work, we investigated whether the earliest regions of somatosensory cortex (S1 and S2) would contain content-specific information about visual object categories. We reasoned that this might be possible due to the associations formed through experience that link different sensory aspects of a given object. Participants were presented with visual images of different object categories in 2 fMRI experiments. Multivariate pattern analysis revealed reliable decoding of familiar visual object category in bilateral S1 (i.e., postcentral gyri) and right S2. We further show that this decoding is observed for familiar but not unfamiliar visual objects in S1. In addition, whole-brain searchlight decoding analyses revealed several areas in the parietal lobe that could mediate the observed context effects between vision and somatosensation. These results demonstrate that even the first cortical stages of somatosensory processing carry information about the category of visually presented familiar objects. PMID:24122136

  8. Brain micromotion around implants in the rodent somatosensory cortex

    Science.gov (United States)

    Gilletti, Aaron; Muthuswamy, Jit

    2006-09-01

    The magnitude of brain tissue micromotion relative to stationary brain implants and its impact on the viability and function of the surrounding brain tissue due to mechanical stresses is poorly understood. The central goal of this study is to characterize surface micromotion in the somatosensory cortex against stationary cylindrical implants. We used a differential variable reluctance transducer (DVRT) in adult rats (n = 6) to monitor micromotion normal to the somatosensory cortex surface. Experiments were performed both in the presence and in the absence of dura mater and displacement measurements were made at three different locations within craniotomies of two different sizes. In anesthetized rats, pulsatile surface micromotion was observed to be in the order of 10-30 µm due to pressure changes during respiration and 2-4 µm due to vascular pulsatility. Brain displacement values due to respiration were significantly lower in the presence of the dura compared to those without the dura. In addition, large inward displacements of brain tissue between 10-60 µm were observed in n = 3 animals immediately following the administration of anesthesia. Such significant micromotion can impact a wide variety of acute and chronic procedures involving any brain implants, precise neurosurgery or imaging and therefore has to be factored in the design of such procedures.

  9. Reappraisal of the somatosensory homunculus and its discontinuities.

    Science.gov (United States)

    Parpia, Pasha

    2011-12-01

    Neuroscience folklore has it that somatotopy in human primary somatosensory cortex (SI) has two significant discontinuities: the hands and face map onto adjacent regions in SI, as do the feet and genitalia. It has been proposed that these conjunctions in SI result from coincident sources of stimulation in the fetal position, where the hands frequently touch the face, and the feet the genitalia. Computer modeling using a Hebbian variant of the self-organizing Kohonen net is consistent with this proposal. However, recent work reveals that the genital representation in SI for cutaneous sensations (as opposed to tumescence) is continuous with that of the lower trunk and thigh. This result, in conjunction with reports of separate face innervation and its earlier onset of sensory function, compared to that of the rest of the body, allows a reappraisal of homuncular organization. It is proposed that the somatosensory homunculus comprises two distinct somatotopic regions: the face representation and that of the rest of the body. Principles of self-organization do not account satisfactorily for the overall homuncular map. These results may serve to alert computational modelers that intrinsic developmental factors can override simple rules of plasticity.

  10. Functional connectivity for somatosensory and motor cortex in spastic diplegia.

    Science.gov (United States)

    Burton, Harold; Dixit, Sachin; Litkowski, Patricia; Wingert, Jason R

    2009-12-01

    Functional connectivity (fcMRI) was analyzed in individuals with spastic diplegia and age-matched controls. Pearson correlations (r-values) were computed between resting state spontaneous activity in selected seed regions (sROI) and each voxel throughout the brain. Seed ROI were centered on foci activated by tactile stimulation of the second fingertip in somatosensory and parietal dorsal attention regions. The group with diplegia showed significantly expanded networks for the somatomotor but not dorsal attention areas. These expanded networks overran nearly all topological representations in somatosensory and motor areas despite a sROI in a fingertip focus. A possible underlying cause for altered fcMRI in the group with dipegia, and generally sensorimotor deficits in spastic diplegia, is that prenatal third trimester white-matter injury leads to localized damage to subplate neurons. We hypothesize that intracortical connections become dominant in spastic diplegia through successful competition with diminished or absent thalamocortical inputs. Similar to the effects of subplate ablations on ocular dominance columns (Kanold and Shatz, Neuron 2006;51:627-638), a spike timing-dependent plasticity model is proposed to explain a shift towards intracortical inputs.

  11. A cognitive neuroprosthetic that uses cortical stimulation for somatosensory feedback

    Science.gov (United States)

    Klaes, Christian; Shi, Ying; Kellis, Spencer; Minxha, Juri; Revechkis, Boris; Andersen, Richard A.

    2014-10-01

    Objective. Present day cortical brain-machine interfaces (BMIs) have made impressive advances using decoded brain signals to control extracorporeal devices. Although BMIs are used in a closed-loop fashion, sensory feedback typically is visual only. However medical case studies have shown that the loss of somesthesis in a limb greatly reduces the agility of the limb even when visual feedback is available. Approach. To overcome this limitation, this study tested a closed-loop BMI that utilizes intracortical microstimulation to provide ‘tactile’ sensation to a non-human primate. Main result. Using stimulation electrodes in Brodmann area 1 of somatosensory cortex (BA1) and recording electrodes in the anterior intraparietal area, the parietal reach region and dorsal area 5 (area 5d), it was found that this form of feedback can be used in BMI tasks. Significance. Providing somatosensory feedback has the poyential to greatly improve the performance of cognitive neuroprostheses especially for fine control and object manipulation. Adding stimulation to a BMI system could therefore improve the quality of life for severely paralyzed patients.

  12. Focal dystonia in musicians: Linking motor symptoms to somatosensory dysfunction

    Directory of Open Access Journals (Sweden)

    Juergen eKonczak

    2013-06-01

    Full Text Available Musician’s dystonia (MD is a neurological motor disorder characterized by involuntary contractions of those muscles involved in the play of a musical instrument. It is task-specific and initially only impairs the voluntary control of highly practiced musical motor skills. MD can lead to a severe decrement in a musician’s ability to perform. While the etiology and the neurological pathomechanism of the disease remain unknown, it is known that MD like others forms of focal dystonia is associated with somatosensory deficits, specifically a decreased precision of tactile and proprioceptive perception. The sensory component of the disease becomes also evident by the patients’ use sensory tricks such as touching dystonic muscles to alleviate motor symptoms. The central premise of this paper is that the motor symptoms of MD have a somatosensory origin and are not fully explained as a problem of motor execution. We outline how altered proprioceptive feedback ultimately leads to a loss of voluntary motor control and propose two scenarios that explain why sensory tricks are effective. Sensory tricks are effective, because the sensorimotor system either recruits neural resources normally involved in tactile-proprioceptive (sensory integration, or utilizes a fully functioning motor efference copy mechanism to align experienced with expected sensory feedback. We argue that an enhanced understanding of how a primary sensory deficit interacts with mechanisms of sensorimotor integration in musician’s dystonia provides helpful insights for the design of more effective behavioral therapies.

  13. Maintenance and manipulation of somatosensory information in ventrolateral prefrontal cortex.

    Science.gov (United States)

    Spitzer, Bernhard; Goltz, Dominique; Wacker, Evelin; Auksztulewicz, Ryszard; Blankenburg, Felix

    2014-05-01

    Neuroimaging studies of working memory (WM) suggest that prefrontal cortex may assist sustained maintenance, but also internal manipulation, of stimulus representations in lower-level areas. A different line of research in the somatosensory domain indicates that neuronal activity in ventrolateral prefrontal cortex (VLPFC) may also represent specific memory contents in itself, however leaving open to what extent top-down control on lower-level areas is exerted, or how internal manipulation processes are implemented. We used functional imaging and connectivity analysis to study static maintenance and internal manipulation of tactile working memory contents after physically identical stimulation conditions, in human subjects. While both tasks recruited similar subareas in the inferior frontal gyrus (IFG) in VLPFC, static maintenance of the tactile information was additionally characterized by increased functional coupling between IFG and primary somatosensory cortex. Independently, during internal manipulation, a quantitative representation of the task-relevant information was evident in IFG itself, even in the absence of physical stimulation. Together, these findings demonstrate the functional diversity of activity within VLPFC according to different working memory demands, and underline the role of IFG as a core region in sensory WM processing. Copyright © 2013 Wiley Periodicals, Inc.

  14. Neural correlates of somatosensory processing in patients with neglect.

    Science.gov (United States)

    Hassa, Thomas; Schoenfeld, Mircea Ariel; Dettmers, Christian; Stoppel, Christian Michael; Weiller, Cornelius; Lange, Rüdiger

    2011-01-01

    Recent evidence from neuroimaging studies using visual tasks suggests that the right superior parietal cortex plays a pivotal role for the recovery of neglect. Importantly, neglect-related deficits are not limited to the visual system and have a rather multimodal nature. We employed somatosensory stimulation in patients with neglect in order to analyze activity changes in networks that are presumably associated with this condition. Eleven chronic neglect patients with right hemispherical stroke were investigated with a fMRI paradigm in which the affected and unaffected hand were passively moved. Brain activation was correlated with the performance in clinical neglect tests. Significant positive correlations with brain activation were found for the lesion duration, the performance in bells and letter cancellation tests and the line bisection test. These activated areas formed a distributed pattern in the right superior parietal cortex. The results suggest a shared representation of visual and somatosensory networks in the right superior parietal cortex in patients with right hemispherical strokes and neglect. The spatial pattern of activity in the superior parietal cortex points out to a different representation of changes related to lesion duration and neglect.

  15. Origins of choice-related activity in mouse somatosensory cortex

    Science.gov (United States)

    Yang, Hongdian; Kwon, Sung E.; Severson, Kyle S.; O’Connor, Daniel H.

    2015-01-01

    During perceptual decisions about faint or ambiguous sensory stimuli, even identical stimuli can produce different choices. Spike trains from sensory cortex neurons can predict trial-to-trial variability in choice. Choice-related spiking is widely studied to link cortical activity to perception, but its origins remain unclear. Using imaging and electrophysiology, we found that mouse primary somatosensory cortex neurons showed robust choice-related activity during a tactile detection task. Spike trains from primary mechanoreceptive neurons did not predict choices about identical stimuli. Spike trains from thalamic relay neurons showed highly transient, weak choice-related activity. Intracellular recordings in cortex revealed a prolonged choice-related depolarization in most neurons that was not accounted for by feedforward thalamic input. Top-down axons projecting from secondary to primary somatosensory cortex signaled choice. An intracellular measure of stimulus sensitivity determined which neurons converted choice-related depolarization into spiking. Our results reveal how choice-related spiking emerges across neural circuits and within single neurons. PMID:26642088

  16. Cumulative Culture and Future Thinking: Is Mental Time Travel a Prerequisite to Cumulative Cultural Evolution?

    Science.gov (United States)

    Vale, G. L.; Flynn, E. G.; Kendal, R. L.

    2012-01-01

    Cumulative culture denotes the, arguably, human capacity to build on the cultural behaviors of one's predecessors, allowing increases in cultural complexity to occur such that many of our cultural artifacts, products and technologies have progressed beyond what a single individual could invent alone. This process of cumulative cultural evolution…

  17. QSAR modeling of cumulative environmental end-points for the prioritization of hazardous chemicals.

    Science.gov (United States)

    Gramatica, Paola; Papa, Ester; Sangion, Alessandro

    2018-01-24

    The hazard of chemicals in the environment is inherently related to the molecular structure and derives simultaneously from various chemical properties/activities/reactivities. Models based on Quantitative Structure Activity Relationships (QSARs) are useful to screen, rank and prioritize chemicals that may have an adverse impact on humans and the environment. This paper reviews a selection of QSAR models (based on theoretical molecular descriptors) developed for cumulative multivariate endpoints, which were derived by mathematical combination of multiple effects and properties. The cumulative end-points provide an integrated holistic point of view to address environmentally relevant properties of chemicals.

  18. Is cumulated pyrethroid exposure associated with prediabetes?

    DEFF Research Database (Denmark)

    Hansen, Martin Rune; Jørs, Erik; Lander, Flemming

    2014-01-01

    Pyrethroids are a class of insecticides used widely for vector control programs. Acute pyrethroid poisoning is rare, but well documented, whereas effects of cumulative exposure are insufficiently described, including possible negative effect on glucose regulation. The objective of this study was ...

  19. Psychometric properties of the Cumulated Ambulation Score

    DEFF Research Database (Denmark)

    Ferriero, Giorgio; Kristensen, Morten T; Invernizzi, Marco

    2018-01-01

    . EVIDENCE ACQUISITION: A literature search was conducted on research articles published between 2006 and June 2016 in journals indexed by MEDLINE and Scopus databases using as search item: "Cumulated Ambulation Score"[All Fields], and selecting studies that presented a psychometric analysis of the scale...

  20. A mineral and cumulate perspective to magma differentiation at Nisyros volcano, Aegean arc

    Science.gov (United States)

    Klaver, Martijn; Matveev, Sergei; Berndt, Jasper; Lissenberg, C. Johan; Vroon, Pieter Z.

    2017-12-01

    Lavas and pyroclastic products of Nisyros volcano (Aegean arc, Greece) host a wide variety of phenocryst and cumulate assemblages that offer a unique window into the earliest stages of magma differentiation. This study presents a detailed petrographic study of lavas, enclaves and cumulates spanning the entire volcanic history of Nisyros to elucidate at which levels in the crust magmas stall and differentiate. We present a new division for the volcanic products into two suites based on field occurrence and petrographic features: a low-porphyricity andesite and a high-porphyricity (rhyo)dacite (HPRD) suite. Cumulate fragments are exclusively found in the HPRD suite and are predominantly derived from upper crustal reservoirs where they crystallised under hydrous conditions from melts that underwent prior differentiation. Rarer cumulate fragments range from (amphibole-)wehrlites to plagioclase-hornblendites and these appear to be derived from the lower crust (0.5-0.8 GPa). The suppressed stability of plagioclase and early saturation of amphibole in these cumulates are indicative of high-pressure crystallisation from primitive hydrous melts (≥ 3 wt% H2O). Clinopyroxene in these cumulates has Al2O3 contents up to 9 wt% due to the absence of crystallising plagioclase, and is subsequently consumed in a peritectic reaction to form primitive, Al-rich amphibole (Mg# > 73, 12-15 wt% Al2O3). The composition of these peritectic amphiboles is distinct from trace element-enriched interstitial amphibole in shallower cumulates. Phenocryst compositions and assemblages in both suites differ markedly from the cumulates. Phenocrysts, therefore, reflect shallow crystallisation and do not record magma differentiation in the deep arc crust.

  1. Neuromagnetic correlates of adaptive plasticity across the hand-face border in human primary somatosensory cortex.

    Science.gov (United States)

    Muret, Dollyane; Daligault, Sébastien; Dinse, Hubert R; Delpuech, Claude; Mattout, Jérémie; Reilly, Karen T; Farnè, Alessandro

    2016-04-01

    It is well established that permanent or transient reduction of somatosensory inputs, following hand deafferentation or anesthesia, induces plastic changes across the hand-face border, supposedly responsible for some altered perceptual phenomena such as tactile sensations being referred from the face to the phantom hand. It is also known that transient increase of hand somatosensory inputs, via repetitive somatosensory stimulation (RSS) at a fingertip, induces local somatosensory discriminative improvement accompanied by cortical representational changes in the primary somatosensory cortex (SI). We recently demonstrated that RSS at the tip of the right index finger induces similar training-independent perceptual learning across the hand-face border, improving somatosensory perception at the lips (Muret D, Dinse HR, Macchione S, Urquizar C, Farnè A, Reilly KT.Curr Biol24: R736-R737, 2014). Whether neural plastic changes across the hand-face border accompany such remote and adaptive perceptual plasticity remains unknown. Here we used magnetoencephalography to investigate the electrophysiological correlates underlying RSS-induced behavioral changes across the hand-face border. The results highlight significant changes in dipole location after RSS both for the stimulated finger and for the lips. These findings reveal plastic changes that cross the hand-face border after an increase, instead of a decrease, in somatosensory inputs. Copyright © 2016 the American Physiological Society.

  2. Preserved somatosensory conduction in a patient with complete cervical spinal cord injury.

    Science.gov (United States)

    Awad, Amar; Levi, Richard; Lindgren, Lenita; Hultling, Claes; Westling, Göran; Nyberg, Lars; Eriksson, Johan

    2015-05-01

    Neurophysiological investigation has shown that patients with clinically complete spinal cord injury can have residual motor sparing ("motor discomplete"). In the current study somatosensory conduction was assessed in a patient with clinically complete spinal cord injury and a novel methodology for assessing such preservation is described, in this case indicating "sensory discomplete" spinal cord injury. Blood oxygenation level-dependent functional magnetic resonance imaging (BOLD fMRI) was used to examine the somatosensory system in a healthy subject and in a subject with a clinically complete cervical spinal cord injury, by applying tactile stimulation above and below the level of spinal cord injury, with and without visual feedback. In the participant with spinal cord injury, somatosensory stimulation below the neurological level of the lesion gave rise to BOLD signal changes in the corresponding areas of the somatosensory cortex. Visual feedback of the stimulation strongly modulated the somatosensory BOLD signal, implying that cortico-cortical rather than spino-cortical connections can drive activity in the somatosensory cortex. Critically, BOLD signal change was also evident when the visual feedback of the stimulation was removed, thus demonstrating sensory discomplete spinal cord injury. Given the existence of sensory discomplete spinal cord injury, preserved but hitherto undetected somatosensory conduction might contribute to the unexplained variability related to, for example, the propensity to develop decubitus ulcers and neuropathic pain among patients with clinically complete spinal cord injury.

  3. Distinct vestibular effects on early and late somatosensory cortical processing in humans.

    Science.gov (United States)

    Pfeiffer, Christian; van Elk, Michiel; Bernasconi, Fosco; Blanke, Olaf

    2016-01-15

    In non-human primates several brain areas contain neurons that respond to both vestibular and somatosensory stimulation. In humans, vestibular stimulation activates several somatosensory brain regions and improves tactile perception. However, less is known about the spatio-temporal dynamics of such vestibular-somatosensory interactions in the human brain. To address this issue, we recorded high-density electroencephalography during left median nerve electrical stimulation to obtain Somatosensory Evoked Potentials (SEPs). We analyzed SEPs during vestibular activation following sudden decelerations from constant-velocity (90°/s and 60°/s) earth-vertical axis yaw rotations and SEPs during a non-vestibular control period. SEP analysis revealed two distinct temporal effects of vestibular activation: An early effect (28-32ms post-stimulus) characterized by vestibular suppression of SEP response strength that depended on rotation velocity and a later effect (97-112ms post-stimulus) characterized by vestibular modulation of SEP topographical pattern that was rotation velocity-independent. Source estimation localized these vestibular effects, during both time periods, to activation differences in a distributed cortical network including the right postcentral gyrus, right insula, left precuneus, and bilateral secondary somatosensory cortex. These results suggest that vestibular-somatosensory interactions in humans depend on processing in specific time periods in somatosensory and vestibular cortical regions. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Intrainsular connectivity and somatosensory responsiveness in young children with ASD.

    Science.gov (United States)

    Failla, Michelle D; Peters, Brittany R; Karbasforoushan, Haleh; Foss-Feig, Jennifer H; Schauder, Kimberly B; Heflin, Brynna H; Cascio, Carissa J

    2017-01-01

    The human somatosensory system comprises dissociable paths for discriminative and affective touch, reflected in separate peripheral afferent populations and distinct cortical targets. Differences in behavioral and neural responses to affective touch may have an important developmental role in early social experiences, which are relevant for autism spectrum disorder (ASD). Using probabilistic tractography, we compared the structural integrity of white matter pathways for discriminative and affective touch in young children with ASD and their typically developing (TD) peers. We examined two tracts: (1) a tract linking the thalamus with the primary somatosensory cortex, which carries discriminative tactile information, and (2) a tract linking the posterior insula-the cortical projection target of unmyelinated tactile afferents mediating affective touch-with the anterior insula, which integrates sensory and visceral inputs to interpret emotional salience of sensory stimuli. We investigated associations between tract integrity and performance on a standardized observational assessment measuring tactile discrimination and affective responses to touch. Both the thalamocortical and intrainsular tracts showed reduced integrity (higher mean diffusivity) in the ASD group compared to those in the TD group. Consistent with the previous findings, the ASD group exhibited impaired tactile discriminative ability, more tactile defensiveness, and more sensory seeking (e.g., enthusiastic play or repetitive engagement with a specific tactile stimulus). There was a significant relation between intrainsular tract integrity and tactile seeking. The direction of this relation differed between groups: higher intrainsular mean diffusivity (MD) (reflecting decreased tract integrity) was associated with increased tactile seeking in the TD group but with decreased tactile seeking in the ASD group. In the TD group, decreased tactile defensiveness was also associated with higher intrainsular MD

  5. Voxel-based lesion-symptom mapping of stroke lesions underlying somatosensory deficits

    Science.gov (United States)

    Meyer, Sarah; Kessner, Simon S.; Cheng, Bastian; Bönstrup, Marlene; Schulz, Robert; Hummel, Friedhelm C.; De Bruyn, Nele; Peeters, Andre; Van Pesch, Vincent; Duprez, Thierry; Sunaert, Stefan; Schrooten, Maarten; Feys, Hilde; Gerloff, Christian; Thomalla, Götz; Thijs, Vincent; Verheyden, Geert

    2015-01-01

    The aim of this study was to investigate the relationship between stroke lesion location and the resulting somatosensory deficit. We studied exteroceptive and proprioceptive somatosensory symptoms and stroke lesions in 38 patients with first-ever acute stroke. The Erasmus modified Nottingham Sensory Assessment was used to clinically evaluate somatosensory functioning in the arm and hand within the first week after stroke onset. Additionally, more objective measures such as the perceptual threshold of touch and somatosensory evoked potentials were recorded. Non-parametric voxel-based lesion-symptom mapping was performed to investigate lesion contribution to different somatosensory deficits in the upper limb. Additionally, structural connectivity of brain areas that demonstrated the strongest association with somatosensory symptoms was determined, using probabilistic fiber tracking based on diffusion tensor imaging data from a healthy age-matched sample. Voxels with a significant association to somatosensory deficits were clustered in two core brain regions: the central parietal white matter, also referred to as the sensory component of the superior thalamic radiation, and the parietal operculum close to the insular cortex, representing the secondary somatosensory cortex. Our objective recordings confirmed findings from clinical assessments. Probabilistic tracking connected the first region to thalamus, internal capsule, brain stem, postcentral gyrus, cerebellum, and frontal pathways, while the second region demonstrated structural connections to thalamus, insular and primary somatosensory cortex. This study reveals that stroke lesions in the sensory fibers of the superior thalamocortical radiation and the parietal operculum are significantly associated with multiple exteroceptive and proprioceptive deficits in the arm and hand. PMID:26900565

  6. Somatosensory Impairments in the Upper Limb Poststroke: Distribution and Association With Motor Function and Visuospatial Neglect.

    Science.gov (United States)

    Meyer, Sarah; De Bruyn, Nele; Lafosse, Christophe; Van Dijk, Margaretha; Michielsen, Marc; Thijs, Liselot; Truyens, Veronik; Oostra, Kristine; Krumlinde-Sundholm, Lena; Peeters, Andre; Thijs, Vincent; Feys, Hilde; Verheyden, Geert

    2016-09-01

    A thorough understanding of the presence of different upper-limb somatosensory deficits poststroke and the relation with motor performance remains unclear. Additionally, knowledge about the relation between somatosensory deficits and visuospatial neglect is limited. To investigate the distribution of upper-limb somatosensory impairments and the association with unimanual and bimanual motor outcomes and visuospatial neglect. A cross-sectional observational study was conducted, including 122 patients within 6 months after stroke (median = 82 days; interquartile range = 57-133 days). Somatosensory measurement included the Erasmus MC modification of the (revised) Nottingham Sensory Assessment (Em-NSA), Perceptual Threshold of Touch (PTT), thumb finding test, 2-point discrimination, and stereognosis subscale of the NSA. Upper-limb motor assessment comprised the Fugl-Meyer assessment, motricity index, Action Research Arm Test, and Adult-Assisting Hand Assessment Stroke. Screening for visuospatial neglect was performed using the Star Cancellation Test. Upper-limb somatosensory impairments were common, with prevalence rates ranging from 21% to 54%. Low to moderate Spearman ρ correlations were found between somatosensory and motor deficits (r = 0.22-0.61), with the strongest associations for PTT (r = 0.56-0.61) and stereognosis (r = 0.51-0.60). Visuospatial neglect was present in 27 patients (22%). Between-group analysis revealed somatosensory deficits that occurred significantly more often and more severely in patients with visuospatial neglect (P visuospatial neglect (r = 0.44-0.78) compared with patients without neglect (r = 0.08-0.59). Somatosensory impairments are common in subacute patients poststroke and are related to motor outcome. Visuospatial neglect was associated with more severe upper-limb somatosensory impairments. © The Author(s) 2015.

  7. Family background of modern health worries, somatosensory amplification, and health anxiety: A questionnaire study.

    Science.gov (United States)

    Köteles, Ferenc; Freyler, Anett; Kökönyei, Gyöngyi; Bárdos, György

    2015-12-01

    In the development of somatosensory amplification, health anxiety, and modern health worries, environmental factors seem more important than genetic background. Parental attitudes might represent a major source of learning. In total, 186 adolescents and their parents completed a questionnaire assessing modern health worries, somatosensory amplification, health anxiety, and somatic symptoms. Adolescents' modern health worries, somatosensory amplification, and health anxiety were positively related to respective parental characteristics in regression analyses even after controlling for sociodemographic variables and somatic symptoms. Parental beliefs may play a role in the development of these characteristics. © The Author(s) 2014.

  8. Your hand movements in my somatosensory cortex: a visuo-kinesthetic function in human area 2.

    Science.gov (United States)

    Oouchida, Yutaka; Okada, Tomohisa; Nakashima, Tokuro; Matsumura, Michikazu; Sadato, Norihiro; Naito, Eiichi

    2004-09-15

    Does viewing someone's actions activate a viewer's somatosensory cortex? We tested if visual information of limb movements activated limb sections in somatosensory areas that are normally engaged in kinesthetic processing of the limb. We showed, with functional magnetic resonance imaging in 17 right-handed healthy subjects, that passive observation of flexion-extension movements of an experimenter's right hand activated the observer's contralateral hand section of area 2 which is involved in kinesthetic processing of right hand movements. This could be interpreted as a pragmatic function of the brain that permits visual information to reach the somatosensory area, and suggests human area 2 has an association function between kinesthesia and vision.

  9. Electrical Circuit Modeling for Somatosensory Evoked Fields in Magnetoencephalogram

    Science.gov (United States)

    Ishihara, Shinichi; Tanaka, Keita; Uchikawa, Yoshinori; Kobayashi, Koichiro

    We measured somatosensory evoked fields (SEFs) by applying on electric stimulus to the right finger (medium nerve and ulnar nerve) and the right ankle (posterior tibial nerve) with a 39-channel SQUID system, which can measure magnetic-field components perpendicular (Br) and tangential to the scalp (Bθ, Bφ) simultaneously. To investigate the relationship between phase lag and stimulus repetition frequency (SRF), the delay time of a component synchronized with the SRFs was calculated by convoluting the reference signal and the measured SEF. The phase lag was linear to SRF for at least three different ranges of the SRFs in each SEF data. We simulated the SEF responses based on the results of phase-lag characteristics and determined the parameters for modeling. To quantitatively characterize the component of SEF, we proposed electric circuit model for the characteristics of phase-lag of the SEF with stimuli frequency.

  10. Motor and somatosensory conversion disorder: a functional unawareness syndrome?

    Science.gov (United States)

    Perez, David L; Barsky, Arthur J; Daffner, Kirk; Silbersweig, David A

    2012-01-01

    Although conversion disorder is closely connected to the origins of neurology and psychiatry, it remains poorly understood. In this article, the authors discuss neural and clinical parallels between lesional unawareness disorders and unilateral motor and somatosensory conversion disorder, emphasizing functional neuroimaging/disease correlates. Authors suggest that a functional-unawareness neurobiological framework, mediated by right hemisphere-lateralized, large-scale brain network dysfunction, may play a significant role in the neurobiology of conversion disorder. The perigenual anterior cingulate and the posterior parietal cortices are detailed as important in disease pathophysiology. Further investigations will refine the functional-unawareness concept, clarify the role of affective circuits, and delineate the process through which functional neurologic symptoms emerge.

  11. Listening to another sense: somatosensory integration in the auditory system.

    Science.gov (United States)

    Wu, Calvin; Stefanescu, Roxana A; Martel, David T; Shore, Susan E

    2015-07-01

    Conventionally, sensory systems are viewed as separate entities, each with its own physiological process serving a different purpose. However, many functions require integrative inputs from multiple sensory systems and sensory intersection and convergence occur throughout the central nervous system. The neural processes for hearing perception undergo significant modulation by the two other major sensory systems, vision and somatosensation. This synthesis occurs at every level of the ascending auditory pathway: the cochlear nucleus, inferior colliculus, medial geniculate body and the auditory cortex. In this review, we explore the process of multisensory integration from (1) anatomical (inputs and connections), (2) physiological (cellular responses), (3) functional and (4) pathological aspects. We focus on the convergence between auditory and somatosensory inputs in each ascending auditory station. This review highlights the intricacy of sensory processing and offers a multisensory perspective regarding the understanding of sensory disorders.

  12. Children with autism show reduced somatosensory response: an MEG study.

    Science.gov (United States)

    Marco, Elysa J; Khatibi, Kasra; Hill, Susanna S; Siegel, Bryna; Arroyo, Monica S; Dowling, Anne F; Neuhaus, John M; Sherr, Elliott H; Hinkley, Leighton N B; Nagarajan, Srikantan S

    2012-10-01

    The neural underpinnings of sensory processing differences in autism remain poorly understood. This prospective magnetoencephalography (MEG) study investigates whether children with autism show atypical cortical activity in the primary somatosensory cortex (S1) in comparison with matched controls. Tactile stimuli were clearly detectable, and painless taps were applied to the distal phalanx of the second (D2) and third (D3) fingers of the right and left hands. Three tactile paradigms were administered: an oddball paradigm (standard taps to D3 at an interstimulus interval (ISI) of 0.33 and deviant taps to D2 with ISI ranging from 1.32 s to 1.64 s); a slow-rate paradigm (D2) with an ISI matching the deviant taps in the oddball paradigm; and a fast-rate paradigm (D2) with an ISI matching the standard taps in the oddball. Study subjects were boys (age 7-11 years) with and without autism disorder. Sensory behavior was quantified using the Sensory Profile questionnaire. Boys with autism exhibited smaller amplitude left hemisphere S1 response to slow and deviant stimuli during the right-hand paradigms. In post-hoc analysis, tactile behavior directly correlated with the amplitude of cortical response. Consequently, the children were re-categorized by degree of parent-report tactile sensitivity. This regrouping created a more robust distinction between the groups with amplitude diminution in the left and right hemispheres and latency prolongation in the right hemisphere in the deviant and slow-rate paradigms for the affected children. This study suggests that children with autism have early differences in somatosensory processing, which likely influence later stages of cortical activity from integration to motor response. © 2012 International Society for Autism Research, Wiley Periodicals, Inc.

  13. Atypical visual and somatosensory adaptation in schizophrenia-spectrum disorders

    Science.gov (United States)

    Andrade, G N; Butler, J S; Peters, G A; Molholm, S; Foxe, J J

    2016-01-01

    Neurophysiological investigations in patients with schizophrenia consistently show early sensory processing deficits in the visual system. Importantly, comparable sensory deficits have also been established in healthy first-degree biological relatives of patients with schizophrenia and in first-episode drug-naive patients. The clear implication is that these measures are endophenotypic, related to the underlying genetic liability for schizophrenia. However, there is significant overlap between patient response distributions and those of healthy individuals without affected first-degree relatives. Here we sought to develop more sensitive measures of sensory dysfunction in this population, with an eye to establishing endophenotypic markers with better predictive capabilities. We used a sensory adaptation paradigm in which electrophysiological responses to basic visual and somatosensory stimuli presented at different rates (ranging from 250 to 2550 ms interstimulus intervals, in blocked presentations) were compared. Our main hypothesis was that adaptation would be substantially diminished in schizophrenia, and that this would be especially prevalent in the visual system. High-density event-related potential recordings showed amplitude reductions in sensory adaptation in patients with schizophrenia (N=15 Experiment 1, N=12 Experiment 2) compared with age-matched healthy controls (N=15 Experiment 1, N=12 Experiment 2), and this was seen for both sensory modalities. At the individual participant level, reduced adaptation was more robust for visual compared with somatosensory stimulation. These results point to significant impairments in short-term sensory plasticity across sensory modalities in schizophrenia. These simple-to-execute measures may prove valuable as candidate endophenotypes and will bear follow-up in future work. PMID:27163205

  14. Estimation of cumulative exposures to naphtha at an automobile fuel-injector manufacturing plant.

    Science.gov (United States)

    Rocskay, A Z; Robins, T G; Echeverria, D; Schork, M A; Seixas, N S; White, R F; Proctor, S P

    1993-09-01

    As part of an epidemiologic study of neuropsychological and renal effects of occupational exposure to organic solvents, estimates of cumulative exposure to naphtha were derived for workers at an automobile fuel-injector manufacturing plant. The approach to exposure estimation was relatively unusual in three respects: (1) a marked association between indoor naphtha air concentration and outdoor temperature was modeled and applied to detailed historical temperature data to calculate cumulative exposure estimates; (2) the large number of investigator-generated air samples allowed the use of analyses of variance to compare alternative job-grouping schemes; and (3) the young age of the plant and few process changes allowed for historical exposure estimates with a high degree of confidence. The derived estimates of cumulative exposure appear to offer a firm basis for epidemiologic analyses of exposure-health outcome relationships.

  15. Structural Vibration Monitoring Using Cumulative Spectral Analysis

    Directory of Open Access Journals (Sweden)

    Satoru Goto

    2013-01-01

    Full Text Available This paper describes a resonance decay estimation for structural health monitoring in the presence of nonstationary vibrations. In structural health monitoring, the structure's frequency response and resonant decay characteristics are very important for understanding how the structure changes. Cumulative spectral analysis (CSA estimates the frequency decay by using the impulse response. However, measuring the impulse response of buildings is impractical due to the need to shake the building itself. In a previous study, we reported on system damping monitoring using cumulative harmonic analysis (CHA, which is based on CSA. The current study describes scale model experiments on estimating the hidden resonance decay under non-stationary noise conditions by using CSA for structural condition monitoring.

  16. Power Reactor Docket Information. Annual cumulation (citations)

    International Nuclear Information System (INIS)

    1977-12-01

    An annual cumulation of the citations to the documentation associated with civilian nuclear power plants is presented. This material is that which is submitted to the U.S. Nuclear Regulatory Commission in support of applications for construction and operating licenses. Citations are listed by Docket number in accession number sequence. The Table of Contents is arranged both by Docket number and by nuclear power plant name

  17. Cumulative and Averaging Fission of Beliefs

    OpenAIRE

    Josang, Audun

    2007-01-01

    Belief fusion is the principle of combining separate beliefs or bodies of evidence originating from different sources. Depending on the situation to be modelled, different belief fusion methods can be applied. Cumulative and averaging belief fusion is defined for fusing opinions in subjective logic, and for fusing belief functions in general. The principle of fission is the opposite of fusion, namely to eliminate the contribution of a specific belief from an already fused belief, with the pur...

  18. Higher order cumulants in colorless partonic plasma

    Energy Technology Data Exchange (ETDEWEB)

    Cherif, S. [Sciences and Technologies Department, University of Ghardaia, Ghardaia, Algiers (Algeria); Laboratoire de Physique et de Mathématiques Appliquées (LPMA), ENS-Kouba (Bachir El-Ibrahimi), Algiers (Algeria); Ahmed, M. A. A. [Department of Physics, College of Science, Taibah University Al-Madinah Al-Mounawwarah KSA (Saudi Arabia); Department of Physics, Taiz University in Turba, Taiz (Yemen); Laboratoire de Physique et de Mathématiques Appliquées (LPMA), ENS-Kouba (Bachir El-Ibrahimi), Algiers (Algeria); Ladrem, M., E-mail: mladrem@yahoo.fr [Department of Physics, College of Science, Taibah University Al-Madinah Al-Mounawwarah KSA (Saudi Arabia); Laboratoire de Physique et de Mathématiques Appliquées (LPMA), ENS-Kouba (Bachir El-Ibrahimi), Algiers (Algeria)

    2016-06-10

    Any physical system considered to study the QCD deconfinement phase transition certainly has a finite volume, so the finite size effects are inevitably present. This renders the location of the phase transition and the determination of its order as an extremely difficult task, even in the simplest known cases. In order to identify and locate the colorless QCD deconfinement transition point in finite volume T{sub 0}(V), a new approach based on the finite-size cumulant expansion of the order parameter and the ℒ{sub m,n}-Method is used. We have shown that both cumulants of higher order and their ratios, associated to the thermodynamical fluctuations of the order parameter, in QCD deconfinement phase transition behave in a particular enough way revealing pronounced oscillations in the transition region. The sign structure and the oscillatory behavior of these in the vicinity of the deconfinement phase transition point might be a sensitive probe and may allow one to elucidate their relation to the QCD phase transition point. In the context of our model, we have shown that the finite volume transition point is always associated to the appearance of a particular point in whole higher order cumulants under consideration.

  19. Expansive Soil Crack Depth under Cumulative Damage

    Directory of Open Access Journals (Sweden)

    Bei-xiao Shi

    2014-01-01

    Full Text Available The crack developing depth is a key problem to slope stability of the expansive soil and its project governance and the crack appears under the roles of dry-wet cycle and gradually develops. It is believed from the analysis that, because of its own cohesion, the expansive soil will have a certain amount of deformation under pulling stress but without cracks. The soil body will crack only when the deformation exceeds the ultimate tensile strain that causes cracks. And it is also believed that, due to the combined effect of various environmental factors, particularly changes of the internal water content, the inherent basic physical properties of expansive soil are weakened, and irreversible cumulative damages are eventually formed, resulting in the development of expansive soil cracks in depth. Starting from the perspective of volumetric strain that is caused by water loss, considering the influences of water loss rate and dry-wet cycle on crack developing depth, the crack developing depth calculation model which considers the water loss rate and the cumulative damages is established. Both the proposal of water loss rate and the application of cumulative damage theory to the expansive soil crack development problems try to avoid difficulties in matrix suction measurement, which will surely play a good role in promoting and improving the research of unsaturated expansive soil.

  20. Higher order cumulants in colorless partonic plasma

    International Nuclear Information System (INIS)

    Cherif, S.; Ahmed, M. A. A.; Ladrem, M.

    2016-01-01

    Any physical system considered to study the QCD deconfinement phase transition certainly has a finite volume, so the finite size effects are inevitably present. This renders the location of the phase transition and the determination of its order as an extremely difficult task, even in the simplest known cases. In order to identify and locate the colorless QCD deconfinement transition point in finite volume T 0 (V), a new approach based on the finite-size cumulant expansion of the order parameter and the ℒ m,n -Method is used. We have shown that both cumulants of higher order and their ratios, associated to the thermodynamical fluctuations of the order parameter, in QCD deconfinement phase transition behave in a particular enough way revealing pronounced oscillations in the transition region. The sign structure and the oscillatory behavior of these in the vicinity of the deconfinement phase transition point might be a sensitive probe and may allow one to elucidate their relation to the QCD phase transition point. In the context of our model, we have shown that the finite volume transition point is always associated to the appearance of a particular point in whole higher order cumulants under consideration.

  1. Somatosensory amplification mediates sex differences in psychological distress among cardioverter-defibrillator patients

    DEFF Research Database (Denmark)

    Versteeg, Henneke; Baumert, Jens; Kolb, Christof

    2010-01-01

    The present study examined whether female patients with an implantable cardioverter defibrillator (ICD) report more psychological distress than male patients, and whether somatosensory amplification mediates this relationship. Design: Consecutive ICD patients (N = 241; 33% women) participating...

  2. Spatial and temporal assessment of orofacial somatosensory sensitivity: a methodological study

    DEFF Research Database (Denmark)

    Thygesen, Torben; Nørholt, Sven Erik; Jensen, John

    2007-01-01

    AIMS: To evaluate the sensitivity and reproducibility of a multimodal psychophysical technique for the assessment of both spatial and temporal changes in somatosensory function after an infraorbital nerve block. METHODS: Sixteen healthy volunteers with a mean (+/- SD) age of 22.5 +/- 3.4 years...... of somatosensory function was carried out before the injection (baseline) and after 30 and 60 minutes on both the anesthetized and contralateral (control) side. In addition, the applicability of the psychophysical techniques was tested in pilot experiments in 2 patients before maxillary osteotomy and 3 months...... matrices allowed a spatial description of somatosensory sensitivity. This method may be valuable for studies on changes in somatosensory sensitivity following trauma or orthognathic surgery on the maxilla....

  3. Interfacing the somatosensory system to restore touch and proprioception: essential considerations.

    Science.gov (United States)

    Weber, Douglas J; Friesen, Rebecca; Miller, Lee E

    2012-01-01

    State-of-the-art upper extremity prostheses include anthropomorphic hands with dexterity that approximates that of a human. To be fully useful, these devices will require an advanced somatosensory neural interface to convey tactile and proprioceptive feedback to the user. To this end, microstimulation methods are being developed using microelectrode arrays implanted at various locations along the somatosensory neuraxis, from peripheral nerves to primary somatosensory cortex. There is presently no consensus as to the best approach, although results from animal and human studies lend support for each. The purpose of this review is to outline practical considerations for the design of a somatosensory interface based on present knowledge of the anatomy and physiology, prior attempts to elicit somatic sensations using electrical stimulation, and lessons learned from successful sensory neuroprostheses such as the cochlear implant.

  4. Somatosensory and auditory processing in opioid-exposed newborns with neonatal abstinence syndrome: a magnetoencephalographic approach.

    Science.gov (United States)

    Kivistö, K; Nevalainen, P; Lauronen, L; Tupola, S; Pihko, E; Kivitie-Kallio, S

    2015-01-01

    Opioid exposure during pregnancy is a potential risk factor for the developing central nervous system of the fetus. We studied evoked responses in buprenorphine-exposed newborns who displayed neonatal abstinence syndrome (NAS) to elucidate the possible alterations in functioning of the somatosensory and auditory systems. We compared somatosensory (SEFs) and auditory evoked magnetic fields (AEFs), recorded with magnetoencephalography (MEG), of 11 prenatally buprenorphine-exposed newborns with those of 12 healthy newborns. Peak latencies, source strength and location of SEFs or AEFs were recorded. AEFs were present in all buprenorphine-exposed newborns without significant differences from those of healthy newborns. In contrast, though no group level differences in SEFs existed, at individual level the response deviated from the typical neonatal morphology in four buprenorphine-exposed newborns. Although buprenorphine exposure during pregnancy does not seem to cause constant deficiencies in somatosensory or auditory processing, in some newborns the typical development of somatosensory networks may be - at least transiently - disrupted.

  5. Somatosensory cortices are required for the acquisition of morphine-induced conditioned place preference.

    Directory of Open Access Journals (Sweden)

    Zhiqiang Meng

    Full Text Available BACKGROUND: Sensory system information is thought to play an important role in drug addiction related responses. However, how somatic sensory information participates in the drug related behaviors is still unclear. Many studies demonstrated that drug addiction represents a pathological usurpation of neural mechanisms of learning and memory that normally relate to the pursuit of rewards. Thus, elucidate the role of somatic sensory in drug related learning and memory is of particular importance to understand the neurobiological mechanisms of drug addiction. PRINCIPAL FINDINGS: In the present study, we investigated the role of somatosensory system in reward-related associative learning using the conditioned place preference model. Lesions were made in somatosensory cortices either before or after conditioning training. We found that lesion of somatosensory cortices before, rather than after morphine conditioning impaired the acquisition of place preference. CONCLUSION: These results demonstrate that somatosensory cortices are necessary for the acquisition but not retention of morphine induced place preference.

  6. Modern health worries, subjective somatic symptoms, somatosensory amplification, and health anxiety in adolescents.

    Science.gov (United States)

    Freyler, Anett; Kohegyi, Zita; Köteles, Ferenc; Kökönyei, Gyöngyi; Bárdos, György

    2013-06-01

    The cross-sectional study aimed at the psychometric evaluation of the Modern Health Worries Scale in adolescents and the exploration of the relationship among modern health worries, somatosensory amplification, health anxiety, and somatic symptoms. A total of 480 secondary school students (aged between 14 and 19 years) completed a set of questionnaires. Four-factor structure of the scale was confirmed by confirmatory factor analysis. Modern health worries were connected to somatosensory amplification and health anxiety, and somatosensory amplification and health anxiety were partial mediators of the connection between modern health worries and somatic symptoms. Perceived vulnerability (conceptualized as somatosensory amplification and health anxiety) appears to build a "social-cognitive-emotional bridge" between symptoms and modern health worries.

  7. Direct and crossed effects of somatosensory stimulation on neuronal excitability and motor performance in humans

    NARCIS (Netherlands)

    Veldman, M. P.; Maffiuletti, N. A.; Hallett, M.; Zijdewind, I.; Hortobagyi, T.

    2014-01-01

    This analytic review reports how prolonged periods of somatosensory electric stimulation (SES) with repetitive transcutaneous nerve stimulation can have 'direct' and 'crossed' effects on brain activation, corticospinal excitability, and motor performance. A review of 26 studies involving 315 healthy

  8. A reduced somatosensory gating response in individuals with multiple sclerosis is related to walking impairment.

    Science.gov (United States)

    Arpin, David J; Gehringer, James E; Wilson, Tony W; Kurz, Max J

    2017-10-01

    When identical stimuli are presented in rapid temporal succession, neural responses to the second stimulation are often weaker than those observed for the first. This phenomenon is termed sensory gating and is believed to be an adaptive feature that helps prevent higher-order cortical centers from being flooded with unnecessary information. Recently, sensory gating in the somatosensory system has been linked to deficits in tactile discrimination. Additionally, studies have linked poor tactile discrimination with impaired walking and balance in individuals with multiple sclerosis (MS). In this study, we examine the neural basis of somatosensory gating in patients with MS and healthy controls and assess the relationship between somatosensory gating and walking performance. We used magnetoencephalography to record neural responses to paired-pulse electrical stimulation applied to the right posterior tibial nerve. All participants also walked across a digital mat, which recorded their spatiotemporal gait kinematics. Our results showed the amplitude of the response to the second stimulation was sharply reduced only in controls, resulting in a significantly reduced somatosensory gating in the patients with MS. No group differences were observed in the amplitude of the response to the first stimulation nor the latency of the neural response to either the first or second stimulation. Interestingly, the altered somatosensory gating responses were correlated with aberrant spatiotemporal gait kinematics in the patients with MS. These results suggest that inhibitory GABA circuits may be altered in patients with MS, which impacts somatosensory gating and contributes to the motor performance deficits seen in these patients. NEW & NOTEWORTHY We aimed to determine whether somatosensory gating in patients with multiple sclerosis (MS) differed compared with healthy controls and whether a relationship exists between somatosensory gating and walking performance. We found reduced

  9. Cumulative risk assessment of the exposure to organophosphorus and carbamate insecticides in the dutch diet

    NARCIS (Netherlands)

    Boon, P.E.; Voet, van der H.; Raaij, van M.T.M.; Klaveren, van J.D.

    2008-01-01

    We report the acute cumulative exposure to organophosphorus insecticides (OPs) and carbamates in the Dutch population and young children (1-6 years) via the diet. Residue data were derived from Dutch monitoring programmes performed during 2003-2005, and food consumption levels from the Dutch

  10. Cumulant expansions for measuring water exchange using diffusion MRI

    Science.gov (United States)

    Ning, Lipeng; Nilsson, Markus; Lasič, Samo; Westin, Carl-Fredrik; Rathi, Yogesh

    2018-02-01

    The rate of water exchange across cell membranes is a parameter of biological interest and can be measured by diffusion magnetic resonance imaging (dMRI). In this work, we investigate a stochastic model for the diffusion-and-exchange of water molecules. This model provides a general solution for the temporal evolution of dMRI signal using any type of gradient waveform, thereby generalizing the signal expressions for the Kärger model. Moreover, we also derive a general nth order cumulant expansion of the dMRI signal accounting for water exchange, which has not been explored in earlier studies. Based on this analytical expression, we compute the cumulant expansion for dMRI signals for the special case of single diffusion encoding (SDE) and double diffusion encoding (DDE) sequences. Our results provide a theoretical guideline on optimizing experimental parameters for SDE and DDE sequences, respectively. Moreover, we show that DDE signals are more sensitive to water exchange at short-time scale but provide less attenuation at long-time scale than SDE signals. Our theoretical analysis is also validated using Monte Carlo simulations on synthetic structures.

  11. Subjective somatosensory experiences disclosed by focused attention: cortical-hippocampal-insular and amygdala contributions.

    Directory of Open Access Journals (Sweden)

    Clemens C C Bauer

    Full Text Available In order to explore the neurobiological foundations of qualitative subjective experiences, the present study was designed to correlate objective third-person brain fMRI measures with subjective first-person identification and scaling of local, subtle, and specific somatosensory sensations, obtained directly after the imaging procedure. Thus, thirty-four volunteers were instructed to focus and sustain their attention to either provoked or spontaneous sensations of each thumb during the fMRI procedure. By means of a Likert scale applied immediately afterwards, the participants recalled and evaluated the intensity of their attention and identified specific somatosensory sensations (e.g. pulsation, vibration, heat. Using the subject's subjective scores as covariates to model both attention intensity and general somatosensory experiences regressors, the whole-brain random effect analyses revealed activations in the frontopolar prefrontal cortex (BA10, primary somatosensory cortex (BA1, premotor cortex (BA 6, precuneus (BA 7, temporopolar cortex (BA 38, inferior parietal lobe (BA 39, hippocampus, insula and amygdala. Furthermore, BA10 showed differential activity, with ventral BA10 correlating exclusively with attention (r(32 = 0.54, p = 0.0013 and dorsal BA10 correlating exclusively with somatosensory sensation (r(32 = 0.46, p = 0.007. All other reported brain areas showed significant positive correlations solely with subjective somatosensory experiences reports. These results provide evidence that the frontopolar prefrontal cortex has dissociable functions depending on specific cognitive demands; i.e. the dorsal portion of the frontopolar prefrontal cortex in conjunction with primary somatosensory cortex, temporopolar cortex, inferior parietal lobe, hippocampus, insula and amygdala are involved in the processing of spontaneous general subjective somatosensory experiences disclosed by focused and sustained attention.

  12. Pre-stimulus alpha oscillations over somatosensory cortex predict tactile misperceptions.

    Science.gov (United States)

    Craddock, Matt; Poliakoff, Ellen; El-Deredy, Wael; Klepousniotou, Ekaterini; Lloyd, Donna M

    2017-02-01

    Fluctuations of pre-stimulus oscillatory activity in the somatosensory alpha band (8-14Hz) observed using human EEG and MEG have been shown to influence the detection of supra- and peri-threshold somatosensory stimuli. However, some reports of touch occur even without a stimulus. We investigated the possibility that pre-stimulus alpha oscillations might also influence these false reports of touch - known as tactile misperceptions. We recorded EEG while participants performed the Somatic Signal Detection Task (SSDT), in which participants must detect brief, peri-threshold somatosensory targets. We found that pre-stimulus oscillatory power in the somatosensory alpha range exhibited a negative linear relationship with reporting of touch at electrode clusters over both contralateral and ipsilateral somatosensory regions. As pre-stimulus alpha power increased, the probability of reporting a touch declined; as it decreased, the probability of reporting a touch increased. This relationship was stronger on trials without a somatosensory stimulus than on trials with a somatosensory stimulus, although was present for both trial types. Spatio-temporal cluster-based permutation analysis also found that pre-stimulus alpha was lower on trials when touch was reported - irrespective of whether it was present - over contralateral and ipsilateral somatosensory cortices, as well as left frontocentral areas. We argue that alpha power may reflect changes in response criterion rather than sensitivity alone. Low alpha power relates to a low barrier to reporting a touch even when one is not present, while high alpha power is linked to less frequent reporting of touch overall. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. [Neurophysiological investigations of information processing in the somato-sensory system].

    Science.gov (United States)

    Kunesch, E

    2009-08-01

    The ability of the human hand to perform complex sensorimotor tasks such as tactile exploration and grasping is based on 1. exact encoding of somatosensory information by cutaneous mechanoreceptors, 2. elaborated processing of afferent signals in somatosensory relay stations and cortex fields, 3. rapid and effective interaction of sensory feedback with motor programs, and 4. different modes of sensory control, which can be switched over. (c) Georg Thieme Verlag KG Stuttgart-New York.

  14. Visual-Somatosensory Integration in Older Adults: Links to Sensory Functioning.

    Science.gov (United States)

    Dumas, Kristina; Holtzer, Roee; Mahoney, Jeannette R

    Research investigating multisensory integration (MSI) processes in aging is scarce, but converging evidence for larger behavioral MSI effects in older compared to younger adults exists. The current study employed a three-prong approach to determine whether inherent age-related sensory processing declines were associated with larger (i.e., worse) visual-somatosensory (VS) reaction time (RT) facilitation effects. Non-demented older adults ( n = 156 ; mean age = 77 years; 55% female) without any medical or psychiatric conditions were included. Participants were instructed to make speeded foot-pedal responses as soon as they detected visual, somatosensory, or VS stimulation. Visual acuity was assessed using the Snellen test while somatosensory sensitivity was determined using vibration thresholds. The aims of the current study were to: (1) replicate a reliable MSI effect; (2) investigate the effect of unisensory functioning on VS RT facilitation; and (3) determine whether sensory functioning combination groups manifested differential MSI effects. Results revealed a significant VS RT facilitation effect that was influenced by somatosensory sensitivity but not visual acuity. That is, older adults with poor somatosensory sensitivity demonstrated significantly larger MSI effects than those with intact somatosensory sensitivity. Additionally, a significant interaction between stimulus condition and sensory functioning group suggested that the group with poor visual acuity and poor somatosensory functioning demonstrated the largest MSI effect compared to the other groups. In summary, the current study reveals that worse somatosensory functioning is associated with larger MSI effects in older adults. To our knowledge, this is first study to identify potential mechanisms behind increased RT facilitation in aging.

  15. [Analysis of pudendal nerve somatosensory evoked potentials in the diagnosis of neurogenic impotence].

    Science.gov (United States)

    Salinas Casado, J; Chamorro, M V; Samblas García, R; Esteban Fuertes, M; Aristizábal Agudelo, J M; Delgado Martín, J A; Blázquez Izquierdo, J; Resel Estévez, L

    1997-06-01

    To determine the utility of the somatosensorial evoked potentials of the pudental nerve in the diagnosis of neurogenic impotence. 129 patients with impotence were evaluated by physical examination and neuroandrologic profile. The neuroandrologic profile was assessed by bulbocavernous electromyography, determination of S2-S4 evoked potentials, analysis of the somatosensorial potentials of the pudendal nerve, cavernous smooth muscle electromyography (SPACE), sympathetic skin response and cystometry. The patients with a neurologic lesion presented a significantly longer latency time of the somatosensorial potentials than those with no neurologic lesion. The sensitivity of the somatosensorial potentials was 63% and the specificity was 98%. The sensitivity could be enhanced without significantly lowering specificity by taking 49 msec as the upper limit of normal values in latency time. The determination of the voluntary anal control in the diagnosis of neurogenic impotence was found to have a high specificity (93%), but a low sensitivity (42%). The determination of the somatosensorial potentials, unlike other techniques, could allow diagnosis of lesions of the suprasacral inneveration in the evaluation of neurogenic impotence. The evoked somatosensorial potentials of the pudendal nerve and physical examination have the inconvenience of their low sensitivity in regard to the diagnosis of neurogenic lesion in impotence, mainly because some conditions only affect the peripheral autonomic innervation and the somatic element is spared.

  16. Static Magnetic Field Stimulation over Parietal Cortex Enhances Somatosensory Detection in Humans.

    Science.gov (United States)

    Carrasco-López, Carmen; Soto-León, Vanesa; Céspedes, Virginia; Profice, Paolo; Strange, Bryan A; Foffani, Guglielmo; Oliviero, Antonio

    2017-04-05

    The role of neuronal oscillations in human somatosensory perception is currently unclear. To address this, here we use noninvasive brain stimulation to artificially modulate cortical network dynamics in the context of neurophysiological and behavioral recordings. We demonstrate that transcranial static magnetic field stimulation (tSMS) over the somatosensory parietal cortex increases oscillatory power specifically in the alpha range, without significantly affecting bottom-up thalamocortical inputs indexed by the early cortical component of somatosensory evoked potentials. Critically, we next show that parietal tSMS enhances the detection of near-threshold somatosensory stimuli. Interestingly, this behavioral improvement reflects a decrease of habituation to somatosensation. Our data therefore provide causal evidence that somatosensory perception depends on parietal alpha activity. SIGNIFICANCE STATEMENT Artificially increasing alpha power by placing a powerful magnetic field over the somatosensory cortex overcomes the natural decline in detection probability of a repeated near-threshold sensory stimulus. Copyright © 2017 the authors 0270-6474/17/373840-08$15.00/0.

  17. Human perception of electrical stimulation on the surface of somatosensory cortex.

    Science.gov (United States)

    Hiremath, Shivayogi V; Tyler-Kabara, Elizabeth C; Wheeler, Jesse J; Moran, Daniel W; Gaunt, Robert A; Collinger, Jennifer L; Foldes, Stephen T; Weber, Douglas J; Chen, Weidong; Boninger, Michael L; Wang, Wei

    2017-01-01

    Recent advancement in electrocorticography (ECoG)-based brain-computer interface technology has sparked a new interest in providing somatosensory feedback using ECoG electrodes, i.e., cortical surface electrodes. We conducted a 28-day study of cortical surface stimulation in an individual with arm paralysis due to brachial plexus injury to examine the sensation produced by electrical stimulation of the somatosensory cortex. A high-density ECoG grid was implanted over the somatosensory and motor cortices. Stimulation through cortical surface electrodes over the somatosensory cortex successfully elicited arm and hand sensations in our participant with chronic paralysis. There were three key findings. First, the intensity of perceived sensation increased monotonically with both pulse amplitude and pulse frequency. Second, changing pulse width changed the type of sensation based on qualitative description provided by the human participant. Third, the participant could distinguish between stimulation applied to two neighboring cortical surface electrodes, 4.5 mm center-to-center distance, for three out of seven electrode pairs tested. Taken together, we found that it was possible to modulate sensation intensity, sensation type, and evoke sensations across a range of locations from the fingers to the upper arm using different stimulation electrodes even in an individual with chronic impairment of somatosensory function. These three features are essential to provide effective somatosensory feedback for neuroprosthetic applications.

  18. Development of Human Somatosensory Cortical Functions - What have We Learned from Magnetoencephalography: A Review.

    Science.gov (United States)

    Nevalainen, Päivi; Lauronen, Leena; Pihko, Elina

    2014-01-01

    The mysteries of early development of cortical processing in humans have started to unravel with the help of new non-invasive brain research tools like multichannel magnetoencephalography (MEG). In this review, we evaluate, within a wider neuroscientific and clinical context, the value of MEG in studying normal and disturbed functional development of the human somatosensory system. The combination of excellent temporal resolution and good localization accuracy provided by MEG has, in the case of somatosensory studies, enabled the differentiation of activation patterns from the newborn's primary (SI) and secondary somatosensory (SII) areas. Furthermore, MEG has shown that the functioning of both SI and SII in newborns has particular immature features in comparison with adults. In extremely preterm infants, the neonatal MEG response from SII also seems to potentially predict developmental outcome: those lacking SII responses at term show worse motor performance at age 2 years than those with normal SII responses at term. In older children with unilateral early brain lesions, bilateral alterations in somatosensory cortical activation detected in MEG imply that the impact of a localized insult may have an unexpectedly wide effect on cortical somatosensory networks. The achievements over the last decade show that MEG provides a unique approach for studying the development of the somatosensory system and its disturbances in childhood. MEG well complements other neuroimaging methods in studies of cortical processes in the developing brain.

  19. Transcranial magnetic stimulation techniques to study the somatosensory system: research applications.

    Science.gov (United States)

    Staines, W Richard; Bolton, David A E

    2013-01-01

    The introduction of brain stimulation research techniques such as transcranial magnetic stimulation (TMS) has greatly advanced the understanding of the somatosensory system in humans. Over the last several years, several studies have focused on applying TMS in a variety of contexts to alter transiently the excitability of the somatosensory cortex or regions that project to it and exert some control over its activity in specific behavioral contexts. Specific foci that are discussed in this chapter are methods of repetitive TMS, including theta-burst protocols, delivered to the primary somatosensory cortex that have been shown to affect behavioral indices of somatic sensation such as tactile perception. Similar stimulation techniques can also be applied to distant areas that interact with and modulate activity in somatosensory cortex (i.e., attentional or motor networks). For example, suppression of the dorsolateral prefrontal cortex modifies the attention-modulation of somatosensory information in modality-specific cortices. Overall this chapter is focused on understanding the interaction of activity in systems that function with the somatosensory system in behavioral contexts. These include systems such as those that control attention, whether sustained or selective between sensory modalities, or those that control movement based on targets present in other sensory systems. © 2013 Elsevier B.V. All rights reserved.

  20. Somatosensory system deficits in schizophrenia revealed by MEG during a median-nerve oddball task.

    Science.gov (United States)

    Huang, Ming-Xiong; Lee, Roland R; Gaa, Kathleen M; Song, Tao; Harrington, Deborah L; Loh, Cathy; Theilmann, Rebecca J; Edgar, J Christopher; Miller, Gregory A; Canive, Jose M; Granholm, Eric

    2010-03-01

    Although impairments related to somatosensory perception are common in schizophrenia, they have rarely been examined in functional imaging studies. In the present study, magnetoencephalography (MEG) was used to identify neural networks that support attention to somatosensory stimuli in healthy adults and abnormalities in these networks in patient with schizophrenia. A median-nerve oddball task was used to probe attention to somatosensory stimuli, and an advanced, high-resolution MEG source-imaging method was applied to assess activity throughout the brain. In nineteen healthy subjects, attention-related activation was seen in a sensorimotor network involving primary somatosensory (S1), secondary somatosensory (S2), primary motor (M1), pre-motor (PMA), and paracentral lobule (PCL) areas. A frontal-parietal-temporal "attention network", containing dorsal- and ventral-lateral prefrontal cortex (DLPFC and VLPFC), orbitofrontal cortex (OFC), anterior cingulate cortex (ACC), superior parietal lobule (SPL), inferior parietal lobule (IPL)/supramarginal gyrus (SMG), and temporal lobe areas, was also activated. Seventeen individuals with schizophrenia showed early attention-related hyperactivations in S1 and M1 but hypo-activation in S1, S2, M1, and PMA at later latency in the sensorimotor network. Within this attention network, hypoactivation was found in SPL, DLPFC, orbitofrontal cortex, and the dorsal aspect of ACC. Hyperactivation was seen in SMG/IPL, frontal pole, and the ventral aspect of ACC in patients. These findings link attention-related somatosensory deficits to dysfunction in both sensorimotor and frontal-parietal-temporal networks in schizophrenia.

  1. Sensory preference in speech production revealed by simultaneous alteration of auditory and somatosensory feedback

    Science.gov (United States)

    Lametti, Daniel R.; Nasir, Sazzad M.; Ostry, David J.

    2012-01-01

    The idea that humans learn and maintain accurate speech by carefully monitoring auditory feedback is widely held. But this view neglects the fact that auditory feedback is highly correlated with somatosensory feedback during speech production. Somatosensory feedback from speech movements could be a primary means by which cortical speech areas monitor the accuracy of produced speech. We tested this idea by placing the somatosensory and auditory systems in competition during speech motor learning. To do this, we combined two speech learning paradigms to simultaneously alter somatosensory and auditory feedback in real-time as subjects spoke. Somatosensory feedback was manipulated by using a robotic device that altered the motion path of the jaw. Auditory feedback was manipulated by changing the frequency of the first formant of the vowel sound and playing back the modified utterance to the subject through headphones. The amount of compensation for each perturbation was used as a measure of sensory reliance. All subjects were observed to correct for at least one of the perturbations, but auditory feedback was not dominant. Indeed, some subjects showed a stable preference for either somatosensory or auditory feedback during speech. PMID:22764242

  2. Development of Human Somatosensory Cortical Functions – What have We Learned from Magnetoencephalography: A Review

    Science.gov (United States)

    Nevalainen, Päivi; Lauronen, Leena; Pihko, Elina

    2014-01-01

    The mysteries of early development of cortical processing in humans have started to unravel with the help of new non-invasive brain research tools like multichannel magnetoencephalography (MEG). In this review, we evaluate, within a wider neuroscientific and clinical context, the value of MEG in studying normal and disturbed functional development of the human somatosensory system. The combination of excellent temporal resolution and good localization accuracy provided by MEG has, in the case of somatosensory studies, enabled the differentiation of activation patterns from the newborn’s primary (SI) and secondary somatosensory (SII) areas. Furthermore, MEG has shown that the functioning of both SI and SII in newborns has particular immature features in comparison with adults. In extremely preterm infants, the neonatal MEG response from SII also seems to potentially predict developmental outcome: those lacking SII responses at term show worse motor performance at age 2 years than those with normal SII responses at term. In older children with unilateral early brain lesions, bilateral alterations in somatosensory cortical activation detected in MEG imply that the impact of a localized insult may have an unexpectedly wide effect on cortical somatosensory networks. The achievements over the last decade show that MEG provides a unique approach for studying the development of the somatosensory system and its disturbances in childhood. MEG well complements other neuroimaging methods in studies of cortical processes in the developing brain. PMID:24672468

  3. Human perception of electrical stimulation on the surface of somatosensory cortex.

    Directory of Open Access Journals (Sweden)

    Shivayogi V Hiremath

    Full Text Available Recent advancement in electrocorticography (ECoG-based brain-computer interface technology has sparked a new interest in providing somatosensory feedback using ECoG electrodes, i.e., cortical surface electrodes. We conducted a 28-day study of cortical surface stimulation in an individual with arm paralysis due to brachial plexus injury to examine the sensation produced by electrical stimulation of the somatosensory cortex. A high-density ECoG grid was implanted over the somatosensory and motor cortices. Stimulation through cortical surface electrodes over the somatosensory cortex successfully elicited arm and hand sensations in our participant with chronic paralysis. There were three key findings. First, the intensity of perceived sensation increased monotonically with both pulse amplitude and pulse frequency. Second, changing pulse width changed the type of sensation based on qualitative description provided by the human participant. Third, the participant could distinguish between stimulation applied to two neighboring cortical surface electrodes, 4.5 mm center-to-center distance, for three out of seven electrode pairs tested. Taken together, we found that it was possible to modulate sensation intensity, sensation type, and evoke sensations across a range of locations from the fingers to the upper arm using different stimulation electrodes even in an individual with chronic impairment of somatosensory function. These three features are essential to provide effective somatosensory feedback for neuroprosthetic applications.

  4. Reduction of pain sensitivity after somatosensory therapy in adults with cerebral palsy

    Directory of Open Access Journals (Sweden)

    Inmaculada eRiquelme

    2013-06-01

    Full Text Available Objective. Pain and deficits in somatosensory processing seem to play a relevant role in cerebral palsy (CP. Rehabilitation techniques based on neuroplasticity mechanisms may induce powerful changes in the organization of the primary somatosensory cortex and have been proved to reduce levels of pain and discomfort in neurological pathologies. However, little is known about the efficacy of such interventions for pain sensitivity in CP individuals. Methods. Adults with cerebral palsy participated in the study and were randomly assigned to the intervention (n=17 or the control group (n=20. The intervention group received a somatosensory therapy including 4 types of exercises (touch, proprioception, vibration, and stereognosis. All participants were asked to continue their standardized motor therapy during the study period. Several somatosensory (pain and touch thresholds, stereognosis, propioception, texture recognition and motor parameters (fine motor skills were assessed before, immediately after and three months after the therapy (follow-up. Results. Participants of the intervention group showed a significant reduction on pain sensitivity after treatment and at follow-up after three months, whereas participants in the control group displayed increasing pain sensitivity over time. No improvements were found on touch sensitivity, proprioception, texture recognition or fine motor skills. Conclusions. Data suggest the possibility that somatosensory therapy was effective in eliciting changes in central somatosensory processing. This hypothesis may have implications for future neuromodulatory treatment of pain complaints in children and adults with cerebral palsy.

  5. Experience-induced plasticity of cutaneous maps in the primary somatosensory cortex of adult monkeys and rats.

    Science.gov (United States)

    Xerri, C; Coq, J O; Merzenich, M M; Jenkins, W M

    1996-01-01

    In a first study, the representations of skin surfaces of the hand in the primary somatosensory cortex, area 3b, were reconstructed in owl monkeys and squirrel monkeys trained to pick up food pellets from small, shallow wells, a task which required skilled use of the digits. Training sessions included limited manual exercise over a total period of a few hours of practice. From an early clumsy performance in which many retrieval attempts were required for each successful pellet retrieval, the monkeys exhibited a gradual improvement. Typically, the animals used various combinations of digits before developing a successful retrieval strategy. As the behavior came to be stereotyped, monkeys consistently engaged surfaces of the distal phalanges of one or two digits in the palpation and capture of food pellets from the smallest wells. Microelectrode mapping of the hand surfaces revealed that the glabrous skin of the fingertips predominantly involved in the dexterity task was represented over topographically expanded cortical sectors. Furthermore, cutaneous receptive fields which covered the most frequently stimulated digital tip surfaces were less than half as large as were those representing the corresponding surfaces of control digits. In a second series of experiments, Long-Evans rats were assigned to environments promoting differential tactile experience (standard, enriched, and impoverished) for 80 to 115 days from the time of weaning. A fourth group of young adult rat experienced a severe restriction of forepaw exploratory movement for either 7 or 15 days. Cortical maps derived in the primary somatosensory cortex showed that environmental enrichment induced a substantial enlargement of the cutaneous forepaw representation, and improved its spatial resolution (smaller glabrous receptive fields). In contrast, tactile impoverishment resulted in a degradation of the forepaw representation that was characterized by larger cutaneous receptive fields and the emergence of

  6. Factorized cumulant expansion approximation method for turbulence with reacting and mixing chemical elements of type A + B → Product

    International Nuclear Information System (INIS)

    Meshram, M C

    2013-01-01

    The Lewis–Kraichnan space–time version of Hopf functional formalism is considered for the investigation of turbulence with reacting and mixing chemical elements of type A + B → Product. The equations of motion are written in Fourier space. We first define the characteristic functional (or the moments generating functional) for the joint probability distribution of the velocity vector of the flow field and the reactants’ concentration scalar fields and translate the equations of motion in terms of the differential equations for the characteristic functional. These differential equations for the characteristic functional are further written in terms of the second characteristic functional (or the cumulant generating functional). This helps us in obtaining the equations for various order cumulants. We note from these equations for cumulants the characteristic difficulty of the theory of turbulence that the (n + 1)th order cumulant C (n+1) occurs in the equation for the dynamics of nth order cumulant C n . We use the factorized cumulant expansion approximation method for the present investigation. Under this approximation an arbitrary nth order cumulant C n is expressed in terms of the lower-order cumulants C (2) , C (3) and C (n−1) and thus we obtain a closed but untruncated system of equations for the cumulants. On using the factorized fourth-cumulant approximation method a closed set of equations for the reactants’ energy spectrum functions and the reactants’ energy transfer functions are derived. These equations are solved numerically and the similarity laws of the solutions are derived analytically. The statistical quantities such as the reactants’ energy, the reactants’ enstrophy, the reactants’ scale of segregations and so on are calculated numerically and the statistical laws of these quantities are discussed. Also, the scope of this tool for investigation of turbulent phenomena not covered in the present study is discussed. (paper)

  7. Preserved cumulative semantic interference despite amnesia

    Directory of Open Access Journals (Sweden)

    Gary Michael Oppenheim

    2015-05-01

    As predicted by Oppenheim et al’s (2010 implicit incremental learning account, WRP’s BCN RTs demonstrated strong (and significant repetition priming and semantic blocking effects (Figure 1. Similar to typical results from neurally intact undergraduates, WRP took longer to name pictures presented in semantically homogeneous blocks than in heterogeneous blocks, an effect that increased with each cycle. This result challenges accounts that ascribe cumulative semantic interference in this task to explicit memory mechanisms, instead suggesting that the effect has the sort of implicit learning bases that are typically spared in hippocampal amnesia.

  8. Long and Short Term Cumulative Structural Priming Effects

    OpenAIRE

    Kaschak, Michael P.; Kutta, Timothy J.; Coyle, Jacqueline M.

    2012-01-01

    We present six experiments that examine cumulative structural priming effects (i.e., structural priming effects that accumulate across many utterances). Of particular interest is whether (1) cumulative priming effects transfer across language production tasks and (2) the transfer of cumulative priming effects across tasks persists over the course of a week. Our data suggest that cumulative structural priming effects do transfer across language production tasks (e.g., from written stem complet...

  9. Original and cumulative prospect theory: a discussion of empirical differences

    NARCIS (Netherlands)

    Wakker, P.P.; Fennema, H.

    1997-01-01

    This note discusses differences between prospect theory and cumulative prospect theory. It shows that cumulative prospect theory is not merely a formal correction of some theoretical problems in prospect theory, but it also gives different predictions. Experiments are described that favor cumulative

  10. Chapter 19. Cumulative watershed effects and watershed analysis

    Science.gov (United States)

    Leslie M. Reid

    1998-01-01

    Cumulative watershed effects are environmental changes that are affected by more than.one land-use activity and that are influenced by.processes involving the generation or transport.of water. Almost all environmental changes are.cumulative effects, and almost all land-use.activities contribute to cumulative effects

  11. Third-order cumulants based method for continuous-time errors-in-variables system identification by fractional models

    International Nuclear Information System (INIS)

    Chetoui, Manel; Malti, Rachid; Thomassin, Magalie; Aoun, Mohamed; Najar, Slah; Abdelkrim, Naceur

    2011-01-01

    This paper deals with continuous-time system identification using fractional models in a noisy input/output context. The third-order cumulants based least squares method (tocls) is extended here to fractional models. The derivatives of the third-order cumulants are computed using a new fractional state variable filter. A numerical example is used to demonstrate the performance of the proposed method called ftocls (fractional third-order cumulants based least squares). The effect of the signal-to-noise ratio and the hyperparameter is studied.

  12. Cumulative Environmental Management Association : Wood Buffalo Region

    International Nuclear Information System (INIS)

    Friesen, B.

    2001-01-01

    The recently announced oil sands development of the Wood Buffalo Region in Alberta was the focus of this power point presentation. Both mining and in situ development is expected to total $26 billion and 2.6 million barrels per day of bitumen production. This paper described the economic, social and environmental challenges facing the resource development of this region. In addition to the proposed oil sands projects, this region will accommodate the needs of conventional oil and gas production, forestry, building of pipelines and power lines, municipal development, recreation, tourism, mining exploration and open cast mining. The Cumulative Environmental Management Association (CEMA) was inaugurated as a non-profit association in April 2000, and includes 41 members from all sectors. Its major role is to ensure a sustainable ecosystem and to avoid any cumulative impacts on wildlife. Other work underway includes the study of soil and plant species diversity, and the effects of air emissions on human health, wildlife and vegetation. The bioaccumulation of heavy metals and their impacts on surface water and fish is also under consideration to ensure the quality and quantity of surface water and ground water. 3 figs

  13. Cumulative effects of job characteristics on health.

    Science.gov (United States)

    Fletcher, Jason M; Sindelar, Jody L; Yamaguchi, Shintaro

    2011-05-01

    We examine whether the job characteristics of physical demands and environmental conditions affect individual's health. Five-year cumulative measures of these job characteristics are used to reflect findings in the biological and physiological literature that indicate that cumulative exposure to hazards and stresses harms health. To create our analytic sample, we merge job characteristics from the Dictionary of Occupational Titles with the PSID data set. We control for early and also lagged health measures and a set of pre-determined characteristics to try to address concerns that individuals self-select into jobs. Our results indicate that individuals who work in jobs with the 'worst' conditions experience declines in their health, though this effect varies by demographic group. We also find some evidence that job characteristics are more detrimental to the health of females and older workers. Finally, we report suggestive evidence that earned income, a job characteristic, partially cushions the health impact of physical demands and harsh environmental conditions for workers. These results are robust to inclusion of occupation fixed effects. Copyright © 2010 John Wiley & Sons, Ltd.

  14. Neuronal activity in somatosensory cortex related to tactile exploration

    Science.gov (United States)

    Fortier-Poisson, Pascal

    2015-01-01

    The very light contact forces (∼0.60 N) applied by the fingertips during tactile exploration reveal a clearly optimized sensorimotor strategy. To investigate the cortical mechanisms involved with this behavior, we recorded 230 neurons in the somatosensory cortex (S1), as two monkeys scanned different surfaces with the fingertips in search of a tactile target without visual feedback. During the exploration, the monkeys, like humans, carefully controlled the finger forces. High-friction surfaces offering greater tangential shear force resistance to the skin were associated with decreased normal contact forces. The activity of one group of neurons was modulated with either the normal or tangential force, with little or no influence from the orthogonal force component. A second group responded to kinetic friction or the ratio of tangential to normal forces rather than responding to a specific parameter, such as force magnitude or direction. A third group of S1 neurons appeared to respond to particular vectors of normal and tangential force on the skin. Although 45 neurons correlated with scanning speed, 32 were also modulated by finger forces, suggesting that forces on the finger should be considered as the primary parameter encoding the skin compliance and that finger speed is a secondary parameter that co-varies with finger forces. Neurons (102) were also tested with different textures, and the activity of 62 of these increased or decreased in relation to the surface friction. PMID:26467519

  15. Sensory adaptation to electrical stimulation of the somatosensory nerves.

    Science.gov (United States)

    Graczyk, Emily Lauren; Delhaye, Benoit; Schiefer, Matthew A; Bensmaia, Sliman J; Tyler, Dustin J

    2018-03-19

    Sensory systems adapt their sensitivity to ambient stimulation levels to improve their responsiveness to changes in stimulation. The sense of touch is also subject to adaptation, as evidenced by the desensitization produced by prolonged vibratory stimulation of the skin. Electrical stimulation of nerves elicits tactile sensations that can convey feedback for bionic limbs. In this study, we investigate whether artificial touch is also subject to adaptation, despite the fact that the peripheral mechanotransducers are bypassed. Approach: Using well-established psychophysical paradigms, we characterize the time course and magnitude of sensory adaptation caused by extended electrical stimulation of the residual somatosensory nerves in three human amputees implanted with cuff electrodes. Main results: We find that electrical stimulation of the nerve also induces perceptual adaptation that recovers after cessation of the stimulus. The time course and magnitude of electrically-induced adaptation are equivalent to their mechanically-induced counterparts. Significance: We conclude that, in natural touch, the process of mechanotransduction is not required for adaptation, and artificial touch naturally experiences adaptation-induced adjustments of the dynamic range of sensations. Further, as it does for native hands, adaptation confers to bionic hands enhanced sensitivity to changes in stimulation and thus a more natural sensory experience. . Creative Commons Attribution license.

  16. Neuronal adaptation in the somatosensory system of rodents.

    Science.gov (United States)

    Lampl, I; Katz, Y

    2017-02-20

    The sensory systems in animals constantly monitor the environment and process salient and relevant features while subtracting background activity. This process requires continuous recalibration of neuronal gain based on recent history. Adaptation has been postulated to be the key mechanism by which neurons rapidly tune their response curves to represent the entire dynamic range of external inputs. Rodents heavily rely on their vibrissa system while gathering information about their surroundings using whisking. Neuronal adaptation is observed in all stages of sensory processing, from the whisker follicle through the brainstem and thalamus up to the barrel cortex. In this review, we discuss the intrinsic, synaptic and network mechanisms of adaptation such as short-term synaptic depression, inhibitory suppression, balance between excitation and inhibition as well as the role of cascading adaptation. Furthermore, we describe recent findings about the different intensity dependent adaptation properties in the two major somatosensory pathways and their possible implications about coding. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  17. Studying somatosensory function in Parkinson’s disease using Magnetoencephalography

    DEFF Research Database (Denmark)

    Sridharan, Kousik Sarathy; Johnsen, Erik Lisbjerg; Beniczky, Sándor

    Background Deep  brain stimulation  (DBS)  of subthalamic  nucleus  (STN) significantly alleviates cardinal  motor  symptoms and improves quality of life in Parkinson’s disease (PD)(1).Specifically,  PD  patients have  problems  with sensory  processing,  sensorimotor integration  and  kinesthetic...... awareness. Somatosensory  evoked fields  (SEF) is  an effective tool to study  thesensory perception  and  cortical processing(2). Methods SixPD patients were recruited from the population of STN DBS treated patients atAarhus University Hospital . A clinical interview  including  mini -mental...... processing in PD patients(5). References [1]Just H, Ostergaard K. Health-related quality of life in patientswith advanced Parkinson’s disease treated with deep brain stimulation of thesubthalamic nuclei. Mov. Disord. [Internet]. 2002 May [cited 2013 Nov8];17(3):539–45. [2]Abbruzzese G, Berardelli A...

  18. Ontogeny of somatostatin receptors in the rat somatosensory cortex

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, B.J.; Leroux, P.; Bodenant, C.; Vaudry, H. (Groupe de Recherche en Endocrinologie Moleculaire, CNRS URA 650, Unite Affiliee a l' INSERM, Mont-Saint-Aignan, (France))

    1991-03-08

    The distribution and density of SRIF receptors (SRIF-R) were studied during development in the rat somatosensory cortex by in vitro autoradiography with monoiodinated (Tyr0-DTrp8)S14. In 16-day-old fetuses (E16), intense labeling was evident in the intermediate zone of the cortex while low concentrations of SRIF-R were detected in the marginal and ventricular zones. The highest density of SRIF-R was measured in the intermediate zone at E18. At this stage, labeling was also intense in the internal part of the developing cortical plate; in contrast, the concentration of binding sites associated with the marginal and ventricular zones remained relatively low. Profound modifications in the distribution of SRIF-R appeared at birth. In particular, a transient reduction of receptor density occurred in the cortical plate. During the first postnatal week, the density of receptors measured in the intermediate zone decreased gradually; conversely, high levels of SRIF-R were observed in the developing cortical layers (II to VI). At postpartum day 13 (P13), a stage which just precedes completion of cell migration in the parietal cortex, the most intensely labeled regions were layers V-VI and future layers II-III. From P13 to adulthood, the concentrations of SRIF-R decreased in all cortical layers (I to VI) and the pattern of distribution of receptors at P21 was similar to that observed in the adults.

  19. [Normative aspects of somatosensory evoked P300 components].

    Science.gov (United States)

    Louzã Neto, M R; Maurer, K; Neuhauser, B

    1989-06-01

    Using a somatosensory version of the oddball-paradigma the influence of age and gender on the P300-component and the comparison of the potential after stimulation of the right and left median nerve was studied in 30 healthy right handed volunteers (age: 20-35 years). Latency, amplitude, area and duration of the P300-potential were analysed. No relationship between age, gender and the P300-parameters were observed. The amplitude and the area of the potential obtained from the F3 electrode were greater after stimulation of the right median nerve compared to the potential after stimulation of the left median nerve. All other results were not significantly different. Strong positive correlations between the results after stimulation of the right and left median nerve were observed. These results showed that by a young group of volunteers age and gender did not influence the P300-component. Although the P300-Parameters had a between-subject variability, their mean remained constant over the study, their correlation coefficients were strong positive and the side of stimulation did not influence them (except for the electrode F3).

  20. Axonal dynamics of excitatory and inhibitory neurons in somatosensory cortex.

    Directory of Open Access Journals (Sweden)

    Sally A Marik

    2010-06-01

    Full Text Available Cortical topography can be remapped as a consequence of sensory deprivation, suggesting that cortical circuits are continually modified by experience. To see the effect of altered sensory experience on specific components of cortical circuits, we imaged neurons, labeled with a genetically modified adeno-associated virus, in the intact mouse somatosensory cortex before and after whisker plucking. Following whisker plucking we observed massive and rapid reorganization of the axons of both excitatory and inhibitory neurons, accompanied by a transient increase in bouton density. For horizontally projecting axons of excitatory neurons there was a net increase in axonal projections from the non-deprived whisker barrel columns into the deprived barrel columns. The axon collaterals of inhibitory neurons located in the deprived whisker barrel columns retracted in the vicinity of their somata and sprouted long-range projections beyond their normal reach towards the non-deprived whisker barrel columns. These results suggest that alterations in the balance of excitation and inhibition in deprived and non-deprived barrel columns underlie the topographic remapping associated with sensory deprivation.

  1. Quantitative methods for somatosensory evaluation in atypical odontalgia.

    Science.gov (United States)

    Porporatti, André Luís; Costa, Yuri Martins; Stuginski-Barbosa, Juliana; Bonjardim, Leonardo Rigoldi; Conti, Paulo César Rodrigues; Svensson, Peter

    2015-01-01

    A systematic review was conducted to identify reliable somatosensory evaluation methods for atypical odontalgia (AO) patients. The computerized search included the main databases (MEDLINE, EMBASE, and Cochrane Library). The studies included used the following quantitative sensory testing (QST) methods: mechanical detection threshold (MDT), mechanical pain threshold (MPT) (pinprick), pressure pain threshold (PPT), dynamic mechanical allodynia with a cotton swab (DMA1) or a brush (DMA2), warm detection threshold (WDT), cold detection threshold (CDT), heat pain threshold (HPT), cold pain detection (CPT), and/or wind-up ratio (WUR). The publications meeting the inclusion criteria revealed that only mechanical allodynia tests (DMA1, DMA2, and WUR) were significantly higher and pain threshold tests to heat stimulation (HPT) were significantly lower in the affected side, compared with the contralateral side, in AO patients; however, for MDT, MPT, PPT, CDT, and WDT, the results were not significant. These data support the presence of central sensitization features, such as allodynia and temporal summation. In contrast, considerable inconsistencies between studies were found when AO patients were compared with healthy subjects. In clinical settings, the most reliable evaluation method for AO in patients with persistent idiopathic facial pain would be intraindividual assessments using HPT or mechanical allodynia tests.

  2. Quantitative methods for somatosensory evaluation in atypical odontalgia

    Directory of Open Access Journals (Sweden)

    André Luís PORPORATTI

    2015-01-01

    Full Text Available A systematic review was conducted to identify reliable somatosensory evaluation methods for atypical odontalgia (AO patients. The computerized search included the main databases (MEDLINE, EMBASE, and Cochrane Library. The studies included used the following quantitative sensory testing (QST methods: mechanical detection threshold (MDT, mechanical pain threshold (MPT (pinprick, pressure pain threshold (PPT, dynamic mechanical allodynia with a cotton swab (DMA1 or a brush (DMA2, warm detection threshold (WDT, cold detection threshold (CDT, heat pain threshold (HPT, cold pain detection (CPT, and/or wind-up ratio (WUR. The publications meeting the inclusion criteria revealed that only mechanical allodynia tests (DMA1, DMA2, and WUR were significantly higher and pain threshold tests to heat stimulation (HPT were significantly lower in the affected side, compared with the contralateral side, in AO patients; however, for MDT, MPT, PPT, CDT, and WDT, the results were not significant. These data support the presence of central sensitization features, such as allodynia and temporal summation. In contrast, considerable inconsistencies between studies were found when AO patients were compared with healthy subjects. In clinical settings, the most reliable evaluation method for AO in patients with persistent idiopathic facial pain would be intraindividual assessments using HPT or mechanical allodynia tests.

  3. Development of somatosensory-evoked potentials in foetal sheep: effects of betamethasone.

    Science.gov (United States)

    Anegroaie, P; Frasch, M G; Rupprecht, S; Antonow-Schlorke, I; Müller, T; Schubert, H; Witte, O W; Schwab, M

    2017-05-01

    Antenatal glucocorticoids are used to accelerate foetal lung maturation in babies threatened with premature labour. We examined the influence of glucocorticoids on functional and structural maturation of the central somatosensory pathway in foetal sheep. Somatosensory-evoked potentials (SEP) reflect processing of somatosensory stimuli. SEP latencies are determined by afferent stimuli transmission while SEP amplitudes reveal cerebral processing. After chronic instrumentation of foetal sheep, mothers received saline (n = 9) or three courses of betamethasone (human equivalent dose of 2 × 110 μg kg -1 betamethasone i.m. 24 h apart, n = 12) at 0.7, 0.75 and 0.8 of gestational age. Trigeminal SEP were evoked prior to, 4 and 24 h after each injection and at 0.8 of gestational age before brains were histologically processed. Somatosensory-evoked potentials were already detectable at 0.7 of gestation age. The early and late responses N20 and N200 were the only reproducible peaks over the entire study period. With advancing gestational age, SEP latencies decreased but amplitudes remained unchanged. Acutely, betamethasone did not affect SEP latencies and amplitudes 4 and 24 h following administration. Chronically, betamethasone delayed developmental decrease in the N200 but not N20 latency by 2 weeks without affecting amplitudes. In parallel, betamethasone decreased subcortical white matter myelination but did not affect network formation and synaptic density in the somatosensory cortex. Somatosensory stimuli are already processed by the foetal cerebral cortex at the beginning of the third trimester. Subsequent developmental decrease in SEP latencies suggests ongoing maturation of afferent sensory transmission. Antenatal glucocorticoids affect structural and functional development of the somatosensory system with specific effects at subcortical level. © 2016 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

  4. Effects of observing normal and abnormal goal-directed hand movements on somatosensory cortical activation.

    Science.gov (United States)

    Cheng, Chia-Hsiung

    2018-01-01

    Existing evidence indicates the importance of observing correct, normal actions on the motor cortical activities. However, the exact neurophysiological mechanisms, particularly in the somatosensory system, remain unclear. This study aimed to elucidate the effects of observing normal and abnormal hand movements on the contralateral primary somatosensory (cSI), contralateral (cSII) and ipsilateral (iSII) secondary somatosensory activities. Experiment I was designed to investigate the effects of motor outputs on the somatosensory processing, in which subjects were instructed to relax or manipulate a small cube. Experiment II was tailored to examine the somatosensory responses to the observation of normal (Normal) and abnormal (Abnormal) hand movements. The subjects received electrical stimulation to right median nerve and magnetoencephalography (MEG) recordings during the whole experimental period. Regional cortical activation and functional connectivity were analyzed. Compared to the resting condition, a reduction in cSI and an enhancement of SII activation was found when subjects manipulated a cube, suggesting the motor outputs have an influence on the somatosensory responses. Further investigation of the effects of observing different hand movements showed that cSII activity was significantly stronger in the Normal than Abnormal condition. Moreover, compared with Abnormal condition, a higher cortical coherence of cSI-iSII at theta bands and cSII-iSII at beta bands was found in Normal condition. Conclusively, the present results suggest stronger activation and enhanced functional connectivity within the somatosensory system during the observation of normal than abnormal hand movements. These findings also highlight the importance of viewing normal, correct hands movements in the stroke rehabilitation. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  5. Pain from Dental Implant Placement, Inflammatory Pulpitis Pain, and Neuropathic Pain Present Different Somatosensory Profiles.

    Science.gov (United States)

    Porporatti, André Luís; Bonjardim, Leonardo Rigoldi; Stuginski-Barbosa, Juliana; Bonfante, Estevam Augusto; Costa, Yuri Martins; Rodrigues Conti, Paulo César

    2017-01-01

    To address the two following questions: (1) What kind of somatosensory abnormalities may be characterized in patients receiving dental implants (IMP), in ongoing inflammatory dental pulpitis (IP) patients, and in neuropathic pain (atypical odontalgia [AO]) patients? and (2) What sort of sensory and neural changes may result from dental implant placement surgery and pulpectomy? A total of 60 subjects were divided into three groups: the IMP (n = 20), IP (n = 20), and AO groups (n = 20). Quantitative sensory testing (QST) was performed preoperatively (baseline) for all three groups and postoperatively at 1 month and 3 months after dental implant placement or pulpectomy (in the IMP group and IP group, respectively). Statistical analyses were completed with one-way and two-way analysis of variance and z score transformations (α = 5%). The main findings of this study indicated that: (1) Elevations in mechanical detection threshold (MDT) and in current perception threshold (CPT) related to C-fiber activation, indicating a loss of function, were found at baseline in IP patients; (2) Somatosensory abnormalities such as allodynia, reduced MDT and mechanical pain threshold (MPT), and impaired pain modulation were found in AO patients; (3) No somatosensory alterations after implant placement were found in the IMP group; and (4) Somatosensory alterations in the form of reduction in the CPT related to C-fiber activation were reported 3 months after pulpectomy in the IP group. This study showed that somatosensory abnormalities were evident in AO and IP patients, and somatosensory alterations were seen in IP patients even 3 months after pulpectomy. However, no somatosensory alterations were seen after implant placement.

  6. Ion cumulation by conical cathode electrolysis.

    CERN Document Server

    Grishin, V G

    2002-01-01

    Results of solid-state sodium stearate electrolysis with conical and cylindrical cathodes is presented here. Both electric measurement and conical samples destruction can be explained if a stress developing inside the conical sample is much bigger than in the cylindrical case and there is its unlimited amplification along cone slopes. OTHER KEYWORDS: ion, current, solid, symmetry, cumulation, polarization, depolarization, ionic conductor,superionic conductor, ice, crystal, strain, V-center, V-centre, doped crystal, interstitial impurity, intrinsic color center, high pressure technology, Bridgman, anvil, experiment, crowdion, dielectric, proton, layer, defect, lattice, dynamics, electromigration, mobility, muon catalysis, concentration, doping, dopant, conductivity, pycnonuclear reaction, permittivity, dielectric constant, point defects, interstitials, polarizability, imperfection, defect centers, glass, epitaxy, sodium hydroxide, metallic substrate, crystallization, point, tip, susceptibility, ferroelectric, ...

  7. Sensory gating, inhibition control and gamma oscillations in the human somatosensory cortex.

    Science.gov (United States)

    Cheng, Chia-Hsiung; Chan, Pei-Ying S; Niddam, David M; Tsai, Shang-Yueh; Hsu, Shih-Chieh; Liu, Chia-Yih

    2016-02-04

    Inhibiting the responses to irrelevant stimuli is an essential component of human cognitive function. Pre-attentive auditory sensory gating (SG), an attenuated neural activation to the second identical stimulus, has been found to be related to the performance of higher-hierarchical brain function. However, it remains unclear whether other cortical regions, such as somatosensory cortex, also possess similar characteristics, or if such a relationship is modality-specific. This study used magnetoencephalography to record neuromagnetic responses to paired-pulse electrical stimulation to median nerve in 22 healthy participants. Somatosensory SG ratio and cortical brain oscillations were obtained and compared with the behavioral performance of inhibition control, as evaluated by somatosensory and auditory Go-Nogo tasks. The results showed that somatosensory P35m SG ratio correlated with behavioral performance of inhibition control. Such relationship was also established in relation to the auditory Go-Nogo task. Finally, a higher frequency value of evoked gamma oscillations was found to relate to a better somatosensory SG ability. In conclusion, our data provided an empirical link between automatic cortical inhibition and behavioral performance of attentive inhibition control. This study invites further research on the relationships among gamma oscillations, neurophysiological indices, and behavioral performance in clinical populations in terms of SG or cortical inhibition.

  8. Illusory and veridical mapping of tactile objects in the primary somatosensory and posterior parietal cortex.

    Science.gov (United States)

    Bufalari, Ilaria; Di Russo, Francesco; Aglioti, Salvatore Maria

    2014-07-01

    While several behavioral and neuroscience studies have explored visual, auditory, and cross-modal illusions, information about the phenomenology and neural correlates of somatosensory illusions is meager. By combining psychophysics and somatosensory evoked potentials, we explored in healthy humans the neural correlates of 2 compelling tactuo-proprioceptive illusions, namely Aristotle (1 object touching the contact area between 2 crossed fingers is perceived as 2 lateral objects) and Reverse illusions (2 lateral objects are perceived as 1 between crossed-fingers object). These illusions likely occur because of the tactuo-proprioceptive conflict induced by fingers being crossed in a non-natural posture. We found that different regions in the somatosensory stream exhibit different proneness to the illusions. Early electroencephalographic somatosensory activity (at 20 ms) originating in the primary somatosensory cortex (S1) reflects the phenomenal rather than the physical properties of the stimuli. Notably, later activity (around 200 ms) originating in the posterior parietal cortex is higher when subjects resist the illusions. Thus, while S1 activity is related to illusory perception, PPC acts as a conflict resolver that recodes tactile events from somatotopic to spatiotopic frames of reference and ultimately enables veridical perception. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  9. Pulse-train Stimulation of Primary Somatosensory Cortex Blocks Pain Perception in Tail Clip Test.

    Science.gov (United States)

    Lee, Soohyun; Hwang, Eunjin; Lee, Dongmyeong; Choi, Jee Hyun

    2017-04-01

    Human studies of brain stimulation have demonstrated modulatory effects on the perception of pain. However, whether the primary somatosensory cortical activity is associated with antinociceptive responses remains unknown. Therefore, we examined the antinociceptive effects of neuronal activity evoked by optogenetic stimulation of primary somatosensory cortex. Optogenetic transgenic mice were subjected to continuous or pulse-train optogenetic stimulation of the primary somatosensory cortex at frequencies of 15, 30, and 40 Hz, during a tail clip test. Reaction time was measured using a digital high-speed video camera. Pulse-train optogenetic stimulation of primary somatosensory cortex showed a delayed pain response with respect to a tail clip, whereas no significant change in reaction time was observed with continuous stimulation. In response to the pulse-train stimulation, video monitoring and local field potential recording revealed associated paw movement and sensorimotor rhythms, respectively. Our results show that optogenetic stimulation of primary somatosensory cortex at beta and gamma frequencies blocks transmission of pain signals in tail clip test.

  10. Somatosensory evoked potentials in attention deficit/hyperactivity disorder and tic disorder.

    Science.gov (United States)

    Miyazaki, Masahito; Fujii, Emiko; Saijo, Takahiko; Mori, Kenji; Kagami, Shoji

    2007-06-01

    Both attention deficit/hyperactivity disorder (ADHD) and chronic tic disorder (TD) are hyperkinetic disorders. These disorders often coexist with each other and frequently have sensory components. Therefore, we hypothesized that they might have a common pathophysiology involving the somatosensory system, especially hyper-excitabilities of primary somatosensory area. To evaluate sensory system excitability, we examined somatosensory evoked potentials (SEP) elicited by median nerve stimulation in 18 children with ADHD and 18 children with TD. Three children with ADHD and 8 children with TD showed giant SEP and the peak-to-peak amplitude for N20-P25 was also significantly greater than that obtained from normally developing children (PADHD and PADHD (PADHD and TD, its severity, especially in the left-hemisphere, differs (i.e. TD has left-ward hyper-excitability). The possibility remains that hyper-excitability of the primary somatosensory area is a reason why these disorders often coexist with each other and left-ward hyper-excitability of the primary somatosensory area is a unique feature of TD described for the first time.

  11. Visual and somatosensory information about object shape control manipulative fingertip forces.

    Science.gov (United States)

    Jenmalm, P; Johansson, R S

    1997-06-01

    We investigated the importance of visual versus somatosensory information for the adaptation of the fingertip forces to object shape when humans used the tips of the right index finger and thumb to lift a test object. The angle of the two flat grip surfaces in relation to the vertical plane was changed between trials from -40 to 30 degrees. At 0 degrees the two surfaces were parallel, and at positive and negative angles the object tapered upward and downward, respectively. Subjects automatically adapted the balance between the horizontal grip force and the vertical lift force to the object shape and thereby maintained a rather constant safety margin against frictional slips, despite the huge variation in finger force requirements. Subjects used visual cues to adapt force to object shape parametrically in anticipation of the force requirements imposed once the object was contacted. In the absence of somatosensory information from the digits, sighted subjects still adapted the force coordination to object shape, but without vision and somatosensory inputs the performance was severely impaired. With normal digital sensibility, subjects adapted the force coordination to object shape even without vision. Shape cues obtained by somatosensory mechanisms were expressed in the motor output about 0. 1 sec after contact. Before this point in time, memory of force coordination used in the previous trial controlled the force output. We conclude that both visual and somatosensory inputs can be used in conjunction with sensorimotor memories to adapt the force output to object shape automatically for grasp stability.

  12. Cumulative causation, market transition, and emigration from China.

    Science.gov (United States)

    Liang, Zai; Chunyu, Miao David; Zhuang, Guotu; Ye, Wenzhen

    2008-11-01

    This article reports findings from a recent survey of international migration from China's Fujian Province to the United States. Using the ethnosurvey approach developed in the Mexican Migration Project, the authors conducted surveys in migrant-sending communities in China as well as in destination communities in New York City. Hypotheses are derived from the international migration literature and the market transition debate. The results are generally consistent with hypotheses derived from cumulative causation of migration; however, geographical location creates some differences in migration patterns to the United States. In China as in Mexico, the existence of migration networks increases the propensity of migration for others in the community. In contrast to the Mexican case, among Chinese immigrants, having a previously migrated household member increases the propensity of other household members to migrate only after the debt for previous migration is paid off. In step with market transition theory, the authors also find that political power influences the migration experience from the coastal Fujian Province.

  13. Aging of the somatosensory system: a translational perspective.

    Science.gov (United States)

    Shaffer, Scott W; Harrison, Anne L

    2007-02-01

    Balance in the elderly population is a major concern given the often catastrophic and disabling consequences of fall-related injuries. Structural and functional declines of the somatosensory system occur with aging and potentially contribute to postural instability in older adults. The objectives of this article are: (1) to discuss the evidence regarding age-related anatomical and physiological changes that occur in the peripheral proprioceptive and cutaneous systems, (2) to relate the basic science research to the current evidence regarding clinical changes associated with normal aging, and (3) to review the evidence regarding age-related proprioceptive and cutaneous clinical changes and relate it to research examining balance performance in older adults. The article is organized by an examination of the receptors responsible for activating afferent pathways (muscle spindle, golgi tendon organ, and articular and cutaneous receptors) and the corresponding sensory afferent fibers and neurons. It integrates basic science laboratory findings with clinical evidence suggesting that advanced aging results in a decline in cutaneous sensation and proprioception. The potential relationship between postural instability and sensory impairments in older adults also is discussed. Current laboratory and clinical evidence suggests that aging results in: (1) diverse and nonuniform declines in the morphology and physiological function of the various sensory structures examined, (2) preferential loss of distal large myelinated sensory fibers and receptors, and (3) impaired distal lower-extremity proprioception, vibration and discriminative touch, and balance. These findings provide foundational knowledge that emphasizes the importance of using reliable and valid sensory testing protocols for older adults and the need for further research that clarifies the relationship between sensory impairment and balance.

  14. Using constellation pharmacology to define comprehensively a somatosensory neuronal subclass

    Science.gov (United States)

    Teichert, Russell W.; Memon, Tosifa; Aman, Joseph W.; Olivera, Baldomero M.

    2014-01-01

    Change is intrinsic to nervous systems; change is required for learning and conditioning and occurs with disease progression, normal development, and aging. To better understand mammalian nervous systems and effectively treat nervous-system disorders, it is essential to track changes in relevant individual neurons. A critical challenge is to identify and characterize the specific cell types involved and the molecular-level changes that occur in each. Using an experimental strategy called constellation pharmacology, we demonstrate that we can define a specific somatosensory neuronal subclass, cold thermosensors, across different species and track changes in these neurons as a function of development. Cold thermosensors are uniformly responsive to menthol and innocuous cool temperature (17 °C), indicating that they express TRPM8 channels. A subset of cold thermosensors expressed α7 nicotinic acetylcholine receptors (nAChRs) but not other nAChR subtypes. Differences in temperature threshold of cold thermosensors correlated with functional expression of voltage-gated K channels Kv1.1/1.2: Relatively higher expression of KV1.1/1.2 channels resulted in a higher threshold response to cold temperature. Other signaling components varied during development and between species. In cold thermosensors of neonatal mice and rats, ATP receptors were functionally expressed, but the expression disappeared with development. This developmental change occurred earlier in low-threshold than high-threshold cold thermosensors. Most rat cold thermosensors expressed TRPA1 channels, whereas mouse cold thermosensors did not. The broad implications of this study are that it is now feasible to track changes in receptor and ion-channel expression in individual neuronal subclasses as a function of development, learning, disease, or aging. PMID:24469798

  15. Sensitivity to microstimulation of somatosensory cortex distributed over multiple electrodes

    Directory of Open Access Journals (Sweden)

    Sungshin eKim

    2015-04-01

    Full Text Available Meaningful and repeatable tactile sensations can be evoked by electrically stimulating primary somatosensory cortex. Intracortical microstimulation (ICMS may thus be a viable approach to restore the sense of touch in individuals who have lost it, for example tetraplegic patients. One of the potential limitations of this approach, however, is that high levels of current can damage the neuronal tissue if the resulting current densities are too high. The limited range of safe ICMS amplitudes thus limits the dynamic range of ICMS-evoked sensations. One way to get around this limitation would be to distribute the ICMS over multiple electrodes in the hopes of intensifying the resulting percept without increasing the current density experienced by the neuronal tissue. Here, we test whether stimulating through multiple electrodes is a viable solution to increase the dynamic range of ICMS-elicited sensations without increasing the peak current density. To this end, we compare the ability of non-human primates to detect ICMS delivered through one versus multiple electrodes. We also compare their ability to discriminate pulse trains differing in amplitude when these are delivered through one or more electrodes. We find that increasing the number of electrodes through which ICMS is delivered only has a marginal effect on detectability or discriminability despite the fact that 2-4 times more current is delivered overall. Furthermore, the impact of multielectrode stimulation (or lack thereof is found whether pulses are delivered synchronously or asynchronously, whether the leading phase of the pulses is cathodic or anodic, and regardless of the spatial configuration of the electrode groups.

  16. LTP-like changes induced by paired associative stimulation of the primary somatosensory cortex in humans : source analysis and associated changes in behaviour

    NARCIS (Netherlands)

    Litvak, V.; Zeller, D.; Oostenveld, R.; Maris, E.G.G.; Cohen, A.; Schramm, A.; Gentner, R.; Zaaroor, M.; Pratt, H.; Classen, J.

    2007-01-01

    Paired associative stimulation (PAS), which combines repetitive peripheral nerve stimulation with transcranial magnetic stimulation (TMS), may induce neuroplastic changes in somatosensory cortex (S1), possibly by long-term potentiation-like mechanisms. We used multichannel median nerve somatosensory

  17. Beta 2-adrenergic receptors are colocalized and coregulated with whisker barrels in rat somatosensory cortex

    Energy Technology Data Exchange (ETDEWEB)

    Vos, P.; Kaufmann, D.; Hand, P.J.; Wolfe, B.B. (Univ. of Pennsylvania, Philadelphia (USA))

    1990-07-01

    Autoradiography has been used to visualize independently the subtypes of beta-adrenergic receptors in rat somatosensory cortex. Beta 2-adrenergic receptors, but not beta 1-adrenergic receptors colocalize with whisker barrels in this tissue. Thus, each whisker sends a specific multisynaptic pathway to the somatosensory cortex that can be histochemically visualized and only one subtype of beta-adrenergic receptor is specifically associated with this cortical representation. Additionally, neonatal lesion of any or all of the whisker follicles results in loss of the corresponding barrel(s) as shown by histochemical markers. This loss is paralleled by a similar loss in the organization of beta 2-adrenergic receptors in the somatosensory cortex. Other results indicate that these beta 2-adrenergic receptors are not involved in moment-to-moment signal transmission in this pathway and, additionally, are not involved in a gross way in the development of whisker-barrel array.

  18. A mutant with bilateral whisker to barrel inputs unveils somatosensory mapping rules in the cerebral cortex.

    Science.gov (United States)

    Renier, Nicolas; Dominici, Chloé; Erzurumlu, Reha S; Kratochwil, Claudius F; Rijli, Filippo M; Gaspar, Patricia; Chédotal, Alain

    2017-03-28

    In mammals, tactile information is mapped topographically onto the contralateral side of the brain in the primary somatosensory cortex (S1). In this study, we describe Robo3 mouse mutants in which a sizeable fraction of the trigemino-thalamic inputs project ipsilaterally rather than contralaterally. The resulting mixture of crossed and uncrossed sensory inputs creates bilateral whisker maps in the thalamus and cortex. Surprisingly, these maps are segregated resulting in duplication of whisker representations and doubling of the number of barrels without changes in the size of S1. Sensory deprivation shows competitive interactions between the ipsi/contralateral whisker maps. This study reveals that the somatosensory system can form a somatotopic map to integrate bilateral sensory inputs, but organizes the maps in a different way from that in the visual or auditory systems. Therefore, while molecular pre-patterning constrains their orientation and position, preservation of the continuity of inputs defines the layout of the somatosensory maps.

  19. Novel assessment of cortical response to somatosensory stimuli in children with hemiparetic cerebral palsy.

    Science.gov (United States)

    Maitre, Nathalie L; Barnett, Zachary P; Key, Alexandra P F

    2012-10-01

    The brain's response to somatosensory stimuli is essential to experience-driven learning in children. It was hypothesized that advances in event-related potential technology could quantify the response to touch in somatosensory cortices and characterize the responses of hemiparetic children. In this prospective study of 8 children (5-8 years old) with hemiparetic cerebral palsy, both event-related potential responses to sham or air puff trials and standard functional assessments were used. Event-related potential technology consistently measured signals reflecting activity in the primary and secondary somatosensory cortices as well as complex cognitive processing of touch. Participants showed typical early responses but less efficient perceptual processes. Significant differences between affected and unaffected extremities correlated with sensorimotor testing, stereognosis, and 2-point discrimination (r > 0.800 and P = .001 for all). For the first time, a novel event-related potential paradigm shows that hemiparetic children have slower and less efficient tactile cortical perception in their affected extremities.

  20. Multimodal interactions between proprioceptive and cutaneous signals in primary somatosensory cortex

    Science.gov (United States)

    Kim, Sung Soo; Gomez-Ramirez, Manuel; Thakur, Pramodsingh H.; Hsiao, Steven S.

    2015-01-01

    The classical view of somatosensory processing holds that proprioceptive and cutaneous inputs are conveyed to cortex through segregated channels, initially synapsing in modality-specific areas 3a (proprioception) and 3b (cutaneous) of primary somatosensory cortex (SI). These areas relay their signals to areas 1 and 2 where multimodal convergence first emerges. However, proprioceptive and cutaneous maps have traditionally been characterized using unreliable stimulation tools. Here, we employed a mechanical stimulator that reliably positioned animals' hands in different postures and presented tactile stimuli with superb precision. Single-unit recordings in SI revealed that most neurons responded to cutaneous and proprioceptive stimuli, including cells in areas 3a and 3b. Multimodal responses were characterized by linear and nonlinear effects that emerged during early (∼20ms) and latter (>100ms) stages of stimulus processing, respectively. These data are incompatible with the modality specificity model in SI, and provide evidence for distinct mechanisms of multimodal processing in the somatosensory system. PMID:25864632

  1. Unilaterally applied stimuli in a frequency discrimination task are represented bilaterally in primary somatosensory cortex.

    Science.gov (United States)

    Tan, H-R M; Wühle, A; Braun, C

    2004-11-30

    Psychophysical studies have shown that there is somatotopically organized interaction in tasks involving somatosensory memory. In order to test the hypothesis that the ipsilateral somatosensory cortex contributes to the psychophysically demonstrated interaction, neuromagnetic steady-state responses induced by vibro-tactile stimuli were investigated in a frequency discrimination task. Subjects were requested to indicate whether two stimuli (first and test stimulus) presented subsequently at the index finger of one hand differed with respect to frequency. An interference stimulus interpolated between both stimuli was applied at the little or the index finger of either the left or right hand. Results show that in the present memory task, bilateral activation was found mainly for the test stimulus although stimuli were applied uni-laterally. As revealed by dipole analysis, sources ipsilateral to the side of stimulation were predominantly located in primary somatosensory cortex.

  2. More than a feeling: The bidirectional convergence of semantic visual object and somatosensory processing.

    Science.gov (United States)

    Ekstrand, Chelsea; Neudorf, Josh; Lorentz, Eric; Gould, Layla; Mickleborough, Marla; Borowsky, Ron

    2017-11-01

    Prevalent theories of semantic processing assert that the sensorimotor system plays a functional role in the semantic processing of manipulable objects. While motor execution has been shown to impact object processing, involvement of the somatosensory system has remained relatively unexplored. Therefore, we developed two novel priming paradigms. In Experiment 1, participants received a vibratory hand prime (on half the trials) prior to viewing a picture of either an object interacted primarily with the hand (e.g., a cup) or the foot (e.g., a soccer ball) and reported how they would interact with it. In Experiment 2, the same objects became the prime and participants were required to identify whether the vibratory stimulation occurred to their hand or foot. In both experiments, somatosensory priming effects arose for the hand objects, while foot objects showed no priming benefits. These results suggest that object semantic knowledge bidirectionally converges with the somatosensory system. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Effects of colour exposure on auditory and somatosensory perception--hints for cross-modal plasticity.

    Science.gov (United States)

    Landgrebe, Michael; Nyuyki, Kewir; Frank, Elmar; Steffens, Thomas; Hauser, Simone; Eichhammer, Peter; Hajak, Goran; Langguth, Berthold

    2008-08-01

    It is well known that colour exposure can influence emotions, behaviour and perception. To get further insight into these complex synesthetic phenomena, the effect of colour stimulation on auditory and somatosensory perception was systematically investigated. 14 healthy male volunteers with normal colour vision rated the loudness of auditory stimuli with a standardized scale during exposure to white, red and green light. Furthermore temperature perception was assessed during exposure of the different colours using a thermal sensory analyser. Colour exposure significantly altered auditory and somatosensory perception. Red light enhanced loudness perception and decreased cold pain thresholds, while green light stimulation reduced loudness perception and increased detection and pain thresholds for warm stimuli. This data give further evidence for cross-modal plasticity in human perception. Colour stimulation influences auditory and somatosensory perception and may therefore have potential as a new treatment strategy of phantom perceptions such as tinnitus or chronic pain.

  4. The Influence of Eye Closure on Somatosensory Discrimination: A Trade-off Between Simple Perception and Discrimination.

    Science.gov (United States)

    Götz, Theresa; Hanke, David; Huonker, Ralph; Weiss, Thomas; Klingner, Carsten; Brodoehl, Stefan; Baumbach, Philipp; Witte, Otto W

    2017-06-01

    We often close our eyes to improve perception. Recent results have shown a decrease of perception thresholds accompanied by an increase in somatosensory activity after eye closure. However, does somatosensory spatial discrimination also benefit from eye closure? We previously showed that spatial discrimination is accompanied by a reduction of somatosensory activity. Using magnetoencephalography, we analyzed the magnitude of primary somatosensory (somatosensory P50m) and primary auditory activity (auditory P50m) during a one-back discrimination task in 21 healthy volunteers. In complete darkness, participants were requested to pay attention to either the somatosensory or auditory stimulation and asked to open or close their eyes every 6.5 min. Somatosensory P50m was reduced during a task requiring the distinguishing of stimulus location changes at the distal phalanges of different fingers. The somatosensory P50m was further reduced and detection performance was higher during eyes open. A similar reduction was found for the auditory P50m during a task requiring the distinguishing of changing tones. The function of eye closure is more than controlling visual input. It might be advantageous for perception because it is an effective way to reduce interference from other modalities, but disadvantageous for spatial discrimination because it requires at least one top-down processing stage. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  5. Multimodal and widespread somatosensory abnormalities in persistent shoulder pain in the first 6 months after stroke: an exploratory study

    NARCIS (Netherlands)

    Roosink, M.; van Dongen, R.T.; Buitenweg, J.R.; Renzenbrink, G.J.; Geurts, A.C.H.; IJzerman, M.J.

    2012-01-01

    Roosink M, Van Dongen RT, Buitenweg JR, Renzenbrink GJ, Geurts AC, IJzerman MJ. Multimodal and widespread somatosensory abnormalities in persistent shoulder pain in the first 6 months after stroke: an exploratory study. OBJECTIVE: To explore the role of multimodal and widespread somatosensory

  6. Human primary somatosensory cortex is differentially involved in vibrotaction and nociception.

    Science.gov (United States)

    Lenoir, Cédric; Huang, Gan; Vandermeeren, Yves; Hatem, Samar Marie; Mouraux, André

    2017-07-01

    The role of the primary somatosensory cortex (S1) in vibrotaction is well established. In contrast, its involvement in nociception is still debated. Here we test whether S1 is similarly involved in the processing of nonnociceptive and nociceptive somatosensory input in humans by comparing the aftereffects of high-definition transcranial direct current stimulation (HD-tDCS) of S1 on the event-related potentials (ERPs) elicited by nonnociceptive and nociceptive somatosensory stimuli delivered to the ipsilateral and contralateral hands. Cathodal HD-tDCS significantly affected the responses to nonnociceptive somatosensory stimuli delivered to the contralateral hand: both early-latency ERPs from within S1 (N20 wave elicited by transcutaneous electrical stimulation of median nerve) and late-latency ERPs elicited outside S1 (N120 wave elicited by short-lasting mechanical vibrations delivered to index fingertip, thought to originate from bilateral operculo-insular and cingulate cortices). These results support the notion that S1 constitutes an obligatory relay for the cortical processing of nonnociceptive tactile input originating from the contralateral hemibody. Contrasting with this asymmetric effect of HD-tDCS on the responses to nonnociceptive somatosensory input, HD-tDCS over the sensorimotor cortex led to a bilateral and symmetric reduction of the magnitude of the N240 wave of nociceptive laser-evoked potentials elicited by stimulation of the hand dorsum. Taken together, our results demonstrate in humans a differential involvement of S1 in vibrotaction and nociception. NEW & NOTEWORTHY Whereas the role of the primary somatosensory cortex (S1) in vibrotaction is well established, its involvement in nociception remains strongly debated. By assessing, in healthy volunteers, the effect of high-definition transcranial direct current stimulation over S1, we demonstrate a differential involvement of S1 in vibrotaction and nociception. Copyright © 2017 the American

  7. Effects of repetitive transcranial magnetic stimulation on the somatosensory cortex during prism adaptation.

    Science.gov (United States)

    Yoon, Hee-Chul; Lee, Kyung-Hyun; Huh, Dong-Chan; Lee, Ji-Hang; Lee, Dong-Hyun

    2014-04-01

    Although the behavioral characteristics and the neural correlates of prism adaptation processes have been studied extensively, the underlying mechanism is yet to be investigated. Recently, somatosensory suppression was heralded as a mechanism for the sensory re-alignment process accompanying the adaptation. Somatosensory suppression should facilitate the re-alignment process in the proprioceptive system. The shift in the proprioceptive system takes place mostly during a concurrent visual feedback (CVF) condition; during a terminal visual feedback (TVF) condition, the visual system experiences significant adaptation (visual shift), so somatosensory suppression should have minimal functional consequences under TVF. To test this hypothesis, a repetitive transcranial magnetic stimulation (rTMS) was applied to the primary somatosensory cortex as an artificial somatosensory suppression right after the reaching initiation in CVF and TVF conditions, and changes in adaptation were observed. Because somatosensory suppression is already in effect during CVF, rTMS would cause no significant changes. During TVF with rTMS, however, significantly different patterns of adaptation could be expected when compared to a sham rTMS condition. Young adults (N = 12) participated in 4 sessions (CVF/ TVF, real/sham rTMS); visual proprioceptive, and total shifts were measured. Movement time and curvature of the reaching movement were measured during the adaptation phase. Results showed that while the total shift was unchanged, the proprioceptive shift increased and the visual shift decreased in the TVF condition when rTMS was delivered. However, the total, proprioceptive, and visual shifts were not influenced by rTMS in the CVF condition. Suppression of proprioception induced by the rTMS could be one of the requisites for successful proprioceptive shift during prism adaptation.

  8. A mixed modality paradigm for recording somatosensory and auditory P50 gating

    DEFF Research Database (Denmark)

    Arnfred, S M; He, Chen; Eder, D N

    2001-01-01

    Significant somatosensory evoked potential (SEP) P50 gating has previously been found in young healthy men by the use of identical paired stimuli. In this study, the exploration of the gating paradigm was extended with the addition of a mixed modality paradigm where three different pairs of ident......Significant somatosensory evoked potential (SEP) P50 gating has previously been found in young healthy men by the use of identical paired stimuli. In this study, the exploration of the gating paradigm was extended with the addition of a mixed modality paradigm where three different pairs...

  9. Cortical contributions to sensory gating in the ipsilateral somatosensory cortex during voluntary activity.

    Science.gov (United States)

    Lei, Yuming; Perez, Monica A

    2017-09-15

    It has long been known that the somatosensory cortex gates sensory inputs from the contralateral side of the body. Here, we examined the contribution of the ipsilateral somatosensory cortex (iS1) to sensory gating during index finger voluntary activity. The amplitude of the P25/N33, but not other somatosensory evoked potential (SSEP) components, was reduced during voluntary activity compared with rest. Interhemispheric inhibition between S1s and intracortical inhibition in the S1 modulated the amplitude of the P25/N33. Note that changes in interhemispheric inhibition between S1s correlated with changes in cortical circuits in the ipsilateral motor cortex. Our findings suggest that cortical circuits, probably from somatosensory and motor cortex, contribute to sensory gating in the iS1 during voluntary activity in humans. An important principle in the organization of the somatosensory cortex is that it processes afferent information from the contralateral side of the body. The role of the ipsilateral somatosensory cortex (iS1) in sensory gating in humans remains largely unknown. Using electroencephalographic (EEG) recordings over the iS1 and electrical stimulation of the ulnar nerve at the wrist, we examined somatosensory evoked potentials (SSEPs; P14/N20, N20/P25 and P25/N33 components) and paired-pulse SSEPs between S1s (interhemispheric inhibition) and within (intracortical inhibition) the iS1 at rest and during tonic index finger voluntary activity. We found that the amplitude of the P25/N33, but not other SSEP components, was reduced during voluntary activity compared with rest. Interhemispheric inhibition increased the amplitude of the P25/N33 and intracortical inhibition reduced the amplitude of the P25/N33, suggesting a cortical origin for this effect. The P25/N33 receives inputs from the motor cortex, so we also examined the contribution of distinct sets of cortical interneurons by testing the effect of ulnar nerve stimulation on motor-evoked potentials

  10. Meaning and magnitude of the reduced density matrix cumulants

    Science.gov (United States)

    Hanauer, Matthias; Köhn, Andreas

    2012-06-01

    Within the framework of a generalized normal ordering (GNO), invented by Mukherjee [1], the reduced density matrix cumulants of the (multiconfigurational) reference wave function play a central role, as they arise directly from the contraction rules. The extended Wick theorem allows contractions of an arbitrary number of active annihilators and creators through a cumulant of corresponding rank. Because the cumulant rank truncates naturally only at the number of active spin orbitals, practical applications of the GNO concept seem to rely on a fast convergence of the cumulant series, allowing one to neglect cumulants with high rank. By computing cumulant norms for selected systems (and up to rank 16), we demonstrate that the cumulants decay approximately exponentially with increasing rank for single reference cases, while the convergence is generally slower for multireference cases. When strong left-right correlation is present as in the singlet state of a dissociated N2 molecule, even the cumulant with maximum rank, λ12 ≈ -1.5 for a CAS(6, 6), is not negligible per se. Besides reporting numerical results, the authors reformulate the theory of reduced density matrices and their cumulants using a notation that is particularly easy to handle, highlighting the close connection to conventional statistics. From this statistical approach, a simple interpretation of reduced density matrices and cumulants follows, according to which an n-body cumulant is a measure for the correlation between the occupation numbers of n spin orbitals. This interpretation is also valid for cumulants with ranks exceeding the number of electrons in the system.

  11. 7 CFR 42.132 - Determining cumulative sum values.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Determining cumulative sum values. 42.132 Section 42... Determining cumulative sum values. (a) The parameters for the on-line cumulative sum sampling plans for AQL's... 3 1 2.5 3 1 2 1 (b) At the beginning of the basic inspection period, the CuSum value is set equal to...

  12. Improving cumulative effects assessment in Alberta: Regional strategic assessment

    International Nuclear Information System (INIS)

    Johnson, Dallas; Lalonde, Kim; McEachern, Menzie; Kenney, John; Mendoza, Gustavo; Buffin, Andrew; Rich, Kate

    2011-01-01

    The Government of Alberta, Canada is developing a regulatory framework to better manage cumulative environmental effects from development in the province. A key component of this effort is regional planning, which will lay the primary foundation for cumulative effects management into the future. Alberta Environment has considered the information needs of regional planning and has concluded that Regional Strategic Assessment may offer significant advantages if integrated into the planning process, including the overall improvement of cumulative environmental effects assessment in the province.

  13. Standardization of the cumulative absolute velocity

    International Nuclear Information System (INIS)

    O'Hara, T.F.; Jacobson, J.P.

    1991-12-01

    EPRI NP-5930, ''A Criterion for Determining Exceedance of the Operating Basis Earthquake,'' was published in July 1988. As defined in that report, the Operating Basis Earthquake (OBE) is exceeded when both a response spectrum parameter and a second damage parameter, referred to as the Cumulative Absolute Velocity (CAV), are exceeded. In the review process of the above report, it was noted that the calculation of CAV could be confounded by time history records of long duration containing low (nondamaging) acceleration. Therefore, it is necessary to standardize the method of calculating CAV to account for record length. This standardized methodology allows consistent comparisons between future CAV calculations and the adjusted CAV threshold value based upon applying the standardized methodology to the data set presented in EPRI NP-5930. The recommended method to standardize the CAV calculation is to window its calculation on a second-by-second basis for a given time history. If the absolute acceleration exceeds 0.025g at any time during each one second interval, the earthquake records used in EPRI NP-5930 have been reanalyzed and the adjusted threshold of damage for CAV was found to be 0.16g-set

  14. Children neglected: Where cumulative risk theory fails.

    Science.gov (United States)

    O'Hara, Mandy; Legano, Lori; Homel, Peter; Walker-Descartes, Ingrid; Rojas, Mary; Laraque, Danielle

    2015-07-01

    Neglected children, by far the majority of children maltreated, experience an environment most deficient in cognitive stimulation and language exchange. When physical abuse co-occurs with neglect, there is more stimulation through negative parent-child interaction, which may lead to better cognitive outcomes, contrary to Cumulative Risk Theory. The purpose of the current study was to assess whether children only neglected perform worse on cognitive tasks than children neglected and physically abused. Utilizing LONGSCAN archived data, 271 children only neglected and 101 children neglected and physically abused in the first four years of life were compared. The two groups were assessed at age 6 on the WPPSI-R vocabulary and block design subtests, correlates of cognitive intelligence. Regression analyses were performed, controlling for additional predictors of poor cognitive outcome, including socioeconomic variables and caregiver depression. Children only neglected scored significantly worse than children neglected and abused on the WPPSI-R vocabulary subtest (p=0.03). The groups did not differ on the block design subtest (p=0.4). This study shows that for neglected children, additional abuse may not additively accumulate risk when considering intelligence outcomes. Children experiencing only neglect may need to be referred for services that address cognitive development, with emphasis on the linguistic environment, in order to best support the developmental challenges of neglected children. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Mission Availability for Bounded-Cumulative-Downtime System

    Science.gov (United States)

    Zhou, Yu; Kou, Gang; Ergu, Daji; Peng, Yi

    2013-01-01

    In this research, a mathematics model is proposed to describe the mission availability for bounded-cumulative-downtime system. In the proposed model, the cumulative downtime and cumulative uptime are considered as constraints simultaneously. The mission availability can be defined as the probability that all repairs do not exceed the bounded cumulative downtime constraint of such system before the cumulative uptime has accrued. There are two mutually exclusive cases associated with the probability. One case is the system has not failed, where the probability can be described by system reliability. The other case is the system has failed and the cumulative downtime does not exceed the constraint before the cumulative uptime has accrued. The mathematic description of the probability under the second case is very complex. And the cumulative downtime in a mission can be set as a random variable, whose cumulative distribution means the probability that the failure system can be restored to the operating state. Giving the dependence in the scheduled mission, a mission availability model with closed form expression under this assumption is proposed. Numerical simulations are presented to illustrate the effectiveness of the proposed model. The results indicate that the relative errors are acceptable and the proposed model is effective. Furthermore, three important applications of the proposed mission availability model are discussed. PMID:23843940

  16. Cumulative prospect theory and second order stochastic dominance criteria: an application to mutual funds performance

    OpenAIRE

    Giuseppe De Nadai; Paolo Pianca

    2007-01-01

    In this note using the rules of stochastic dominance of the second order and the recent cumulative prospect theory for classified, according to their performance, a set of common funds. The criteria used are closely linked to the preferences of decision maker and refer to either hypothesis of aversion and of seeking to risk both hypothesis on the sign of derived second of the function which characterizes the losses and gains.

  17. Cervicogenic somatosensory tinnitus: An indication for manual therapy? Part 1: Theoretical concept

    NARCIS (Netherlands)

    Oostendorp, R.A.B.; Bakker, I.; Elvers, H.; Mikolajewska, E.; Michiels, S.; Hertogh, W. de; Samwel, H.

    2016-01-01

    Tinnitus can be evoked or modulated by input from the somatosensory and somatomotor systems. This means that the loudness or intensity of tinnitus can be changed by sensory or motor stimuli such as muscle contractions, mechanical pressure on myofascial trigger points, transcutaneous electrical

  18. Predictability of painful stimulation modulates the somatosensory-evoked potential in the rat

    NARCIS (Netherlands)

    Schaap, M.W.H.; van Oostrom, H.; Doornenbal, A.; Baars, A.M.; Arndt, S.S.; Hellebrekers, L.J.

    2013-01-01

    Abstract Somatosensory-evoked potentials (SEPs) are used in humans and animals to increase knowledge about nociception and pain. Since the SEP in humans increases when noxious stimuli are administered unpredictably, predictability potentially influences the SEP in animals as well. To assess the

  19. Effect of surgery on sensory threshold and somatosensory evoked potentials after skin stimulation

    DEFF Research Database (Denmark)

    Lund, C; Hansen, O B; Kehlet, H

    1990-01-01

    We have studied the effect of surgical injury on cutaneous sensitivity and somatosensory evoked potentials (SSEP) to dermatomal electrical stimulation in 10 patients undergoing hysterectomy. Forty-eight hours after surgery, sensory threshold increased from 2.2 (SEM 0.3) mA to 4.4 (1.1) mA (P less...

  20. cTBS delivered to the left somatosensory cortex changes its functional connectivity during rest

    NARCIS (Netherlands)

    Valchev, Nikola; Curcic-Blake, Branisalava; Renken, Remco J.; Avenanti, Alessio; Keysers, Christian; Gazzola, Valeria; Maurits, Natasha M.

    2015-01-01

    The primary somatosensory cortex (SI) plays a critical role in somatosensation as well as in action performance and social cognition. Although the SI has been a major target of experimental and clinical research using non-invasive transcranial magnetic stimulation (TMS), to date information on the

  1. Volumetric localization of somatosensory cortex in children using synthetic aperture magnetometry

    Energy Technology Data Exchange (ETDEWEB)

    Xiang, Jing [Department of Diagnostic Imaging, The Hospital for Sick Children, 555 University Avenue, Toronto, ON (Canada); Research Institute, Hospital for Sick Children, 555 University Avenue, Toronto, ON (Canada); Holowka, Stephanie; Chuang, Sylvester [Department of Diagnostic Imaging, The Hospital for Sick Children, 555 University Avenue, Toronto, ON (Canada); Sharma, Rohit; Hunjan, Amrita; Otsubo, Hiroshi [Department of Neurology, Hospital for Sick Children, 555 University Avenue, Toronto, ON (Canada)

    2003-05-01

    Magnetic signal from the human brain can be measured noninvasively by using magnetoencephalography (MEG). This study was designed to localize and reconstruct the neuromagnetic activity in the somatosensory cortex in children Twenty children were studied using a 151-channel MEG system with electrical stimulation applied to median nerves. Data were analyzed using synthetic aperture magnetometry (SAM). A clear deflection (M1) was clearly identified in 18 children (90%, 18/20). Two frequency bands, 30-60 Hz and 60-120 Hz, were found to be related to somatosensory cortex. Magnetic activity was localized in the posterior bank of the central sulcus in 16 children. The extent of the reconstructed neuromagnetic activity of the left hemisphere was significantly larger than that of the right hemisphere (P<0.01). Somatosensory cortex was accurately localized by using SAM. The extent of the reconstructed neuromagnetic activity suggested that the left hemisphere was the dominant side in the somatosensory system in children. We postulate that the volumetric characteristics of the reconstructed neuromagnetic activity are able to indicate the functionality of the brain. (orig.)

  2. Plasticity-Inducing TMS Protocols to Investigate Somatosensory Control of Hand Function

    Directory of Open Access Journals (Sweden)

    M. Jacobs

    2012-01-01

    Full Text Available Hand function depends on sensory feedback to direct an appropriate motor response. There is clear evidence that somatosensory cortices modulate motor behaviour and physiology within primary motor cortex. However, this information is mainly from research in animals and the bridge to human hand control is needed. Emerging evidence in humans supports the notion that somatosensory cortices modulate motor behaviour, physiology and sensory perception. Transcranial magnetic stimulation (TMS allows for the investigation of primary and higher-order somatosensory cortices and their role in control of hand movement in humans. This review provides a summary of several TMS protocols in the investigation of hand control via the somatosensory cortices. TMS plasticity inducing protocols reviewed include paired associative stimulation, repetitive TMS, theta-burst stimulation as well as other techniques that aim to modulate cortical excitability in sensorimotor cortices. Although the discussed techniques may modulate cortical excitability, careful consideration of experimental design is needed to isolate factors that may interfere with desired results of the plasticity-inducing protocol, specifically events that may lead to metaplasticity within the targeted cortex.

  3. A Somatosensory Latency between the Thalamus and Cortex also Correlates with Level of Intelligence.

    Science.gov (United States)

    Reed, T. Edward; Jensen, Arthur R.

    1993-01-01

    Results for sensory thalamocortical latency (3 somatosensory evoked potentials) for 205 college students agree with data that correlate a more extensive visual evoked potential latency with intelligence quotient. Findings suggest that the correlation occurs because the latency indexes cortical nerve conduction velocity. (SLD)

  4. Functional Magnetic Resonance Imaging Connectivity Analyses Reveal Efference-Copy to Primary Somatosensory Area, BA2

    NARCIS (Netherlands)

    Cui, Fang; Arnstein, Dan; Thomas, Rajat Mani; Maurits, Natasha M.; Keysers, Christian; Gazzola, Valeria

    2014-01-01

    Some theories of motor control suggest efference-copies of motor commands reach somatosensory cortices. Here we used functional magnetic resonance imaging to test these models. We varied the amount of efference-copy signal by making participants squeeze a soft material either actively or passively.

  5. Functional magnetic resonance imaging connectivity analyses reveal efference-copy to primary somatosensory area, BA2

    NARCIS (Netherlands)

    Cui, Fang; Arnstein, Dan; Thomas, Rajat Mani; Maurits, Natasha M; Keysers, C.; Gazzola, Valeria

    2014-01-01

    Some theories of motor control suggest efference-copies of motor commands reach somatosensory cortices. Here we used functional magnetic resonance imaging to test these models. We varied the amount of efference-copy signal by making participants squeeze a soft material either actively or passively.

  6. Rhythmic Spontaneous Activity Mediates the Age-Related Decline in Somatosensory Function.

    Science.gov (United States)

    Spooner, Rachel K; Wiesman, Alex I; Proskovec, Amy L; Heinrichs-Graham, Elizabeth; Wilson, Tony W

    2018-01-12

    Sensory gating is a neurophysiological process whereby the response to a second stimulus in a pair of identical stimuli is attenuated, and it is thought to reflect the capacity of the CNS to preserve neural resources for behaviorally relevant stimuli. Such gating is observed across multiple sensory modalities and is modulated by age, but the mechanisms involved are not understood. In this study, we examined somatosensory gating in 68 healthy adults using magnetoencephalography (MEG) and advanced oscillatory and time-domain analysis methods. MEG data underwent source reconstruction and peak voxel time series data were extracted to evaluate the dynamics of somatosensory gating, and the impact of spontaneous neural activity immediately preceding the stimulation. We found that gating declined with increasing age and that older adults had significantly reduced gating relative to younger adults, suggesting impaired local inhibitory function. Most importantly, older adults had significantly elevated spontaneous activity preceding the stimulation, and this effect fully mediated the impact of aging on sensory gating. In conclusion, gating in the somatosensory system declines with advancing age and this effect is directly tied to increased spontaneous neural activity in the primary somatosensory cortices, which is likely secondary to age-related declines in local GABA inhibitory function. © The Author(s) 2018. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  7. Somatosensory functioning and experienced pain in ADHD-families : A pilot study

    NARCIS (Netherlands)

    Scherder, Erik J. A.; Rommelse, Nanda N. J.; Broring, Tinka; Faraone, Stephen V.; Sergeant, Joseph A.

    2008-01-01

    Background: An issue somewhat overlooked in children with Attention Deficit/Hyperactivity Disorder (ADHD) is somatosensory functioning. Some studies show a deficit in the processing of tactile and kinesthetic stimuli, but more research is needed to confirm these findings. A related topic, namely the

  8. Functional roles of rhythmic neuronal activity in the human visual and somatosensory system

    NARCIS (Netherlands)

    Bauer, M.

    2008-01-01

    The main aim of this thesis was to investigate the functional role of synchronised oscillations in sensory systems of the human brain. In the first study we found high-frequency gamma-oscillations in the somatosensory system in response to mechanical tactile stimulation. These stimulus-related

  9. Left Lateralized Enhancement of Orofacial Somatosensory Processing Due to Speech Sounds

    Science.gov (United States)

    Ito, Takayuki; Johns, Alexis R.; Ostry, David J.

    2013-01-01

    Purpose: Somatosensory information associated with speech articulatory movements affects the perception of speech sounds and vice versa, suggesting an intimate linkage between speech production and perception systems. However, it is unclear which cortical processes are involved in the interaction between speech sounds and orofacial somatosensory…

  10. Decoding covert somatosensory attention by a BCI system calibrated with tactile sensation.

    Science.gov (United States)

    Yao, Lin; Sheng, Xinjun; Mrachacz-Kersting, Natalie; Zhu, Xiangyang; Farina, Dario; Jiang, Ning

    2017-10-12

    We propose a novel calibration strategy to facilitate the decoding of covert somatosensory attention by exploring the oscillatory dynamics induced by tactile sensation. It was hypothesized that the similarity of the oscillatory pattern between stimulation sensation (SS, real sensation) and somatosensory attentional orientation (SAO) provides a way to decode covert somatic attention. Subjects were instructed to sense the tactile stimulation, which was applied to the left (SS-L) or the right (SS-R) wrist. The BCI system was calibrated with the sensation data and then applied for online SAO decoding. Both SS and SAO showed oscillatory activation concentrated on the contralateral somatosensory hemisphere. Offline analysis showed that the proposed calibration method led to greater accuracy than the traditional calibration method based on SAO only. This is confirmed by online experiments, where the online accuracy on 15 subjects was %, with 12 subjects >70% and 4 subject >90%. By integrating the stimulus-induced oscillatory dynamics from sensory cortex, covert somatosensory attention can be reliably decoded by a BCI system calibrated with tactile sensation. Indeed, real tactile sensation is more consistent during calibration than SAO. This brain-computer interfacing approach may find application for stroke and completely locked-in patients with preserved somatic sensation.

  11. Age-Related Reduced Somatosensory Gating Is Associated with Altered Alpha Frequency Desynchronization

    Science.gov (United States)

    Cheng, Chia-Hsiung; Chan, Pei-Ying S.; Lin, Yung-Yang

    2015-01-01

    Sensory gating (SG), referring to an attenuated neural response to the second identical stimulus, is considered as preattentive processing in the central nervous system to filter redundant sensory inputs. Insufficient somatosensory SG has been found in the aged adults, particularly in the secondary somatosensory cortex (SII). However, it remains unclear which variables leading to the age-related somatosensory SG decline. There has been evidence showing a relationship between brain oscillations and cortical evoked excitability. Thus, this study used whole-head magnetoencephalography to record responses to paired-pulse electrical stimulation to the left median nerve in healthy young and elderly participants to test whether insufficient stimulus 1- (S1-) induced event-related desynchronization (ERD) contributes to a less-suppressed stimulus 2- (S2-) evoked response. Our analysis revealed that the minimum norm estimates showed age-related reduction of SG in the bilateral SII regions. Spectral power analysis showed that the elderly demonstrated significantly reduced alpha ERD in the contralateral SII (SIIc). Moreover, it was striking to note that lower S1-induced alpha ERD was associated with higher S2-evoked amplitudes in the SIIc among the aged adults. Conclusively, our findings suggest that age-related decline of somatosensory SG is partially attributed to the altered S1-induced oscillatory activity. PMID:26417458

  12. Frequency Domain Characterization of the Somatosensory Steady State Response in Electroencephalography

    NARCIS (Netherlands)

    Vlaar, Martijn P.; van der Helm, Frans C.T.; Schouten, Alfred C.

    2015-01-01

    A continuous somatosensory stimulation evokes a steady state response in the cortex, which can be measured using electroencephalography. We applied mechanical multisine stimulation of the wrist to investigate the properties of the steady state response in the frequency domain. Our results show a

  13. Age-Related Reduced Somatosensory Gating Is Associated with Altered Alpha Frequency Desynchronization

    Directory of Open Access Journals (Sweden)

    Chia-Hsiung Cheng

    2015-01-01

    Full Text Available Sensory gating (SG, referring to an attenuated neural response to the second identical stimulus, is considered as preattentive processing in the central nervous system to filter redundant sensory inputs. Insufficient somatosensory SG has been found in the aged adults, particularly in the secondary somatosensory cortex (SII. However, it remains unclear which variables leading to the age-related somatosensory SG decline. There has been evidence showing a relationship between brain oscillations and cortical evoked excitability. Thus, this study used whole-head magnetoencephalography to record responses to paired-pulse electrical stimulation to the left median nerve in healthy young and elderly participants to test whether insufficient stimulus 1- (S1- induced event-related desynchronization (ERD contributes to a less-suppressed stimulus 2- (S2- evoked response. Our analysis revealed that the minimum norm estimates showed age-related reduction of SG in the bilateral SII regions. Spectral power analysis showed that the elderly demonstrated significantly reduced alpha ERD in the contralateral SII (SIIc. Moreover, it was striking to note that lower S1-induced alpha ERD was associated with higher S2-evoked amplitudes in the SIIc among the aged adults. Conclusively, our findings suggest that age-related decline of somatosensory SG is partially attributed to the altered S1-induced oscillatory activity.

  14. Electrophysiological Evidence for a Sensory Recruitment Model of Somatosensory Working Memory.

    Science.gov (United States)

    Katus, Tobias; Grubert, Anna; Eimer, Martin

    2015-12-01

    Sensory recruitment models of working memory assume that information storage is mediated by the same cortical areas that are responsible for the perceptual processing of sensory signals. To test this assumption, we measured somatosensory event-related brain potentials (ERPs) during a tactile delayed match-to-sample task. Participants memorized a tactile sample set at one task-relevant hand to compare it with a subsequent test set on the same hand. During the retention period, a sustained negativity (tactile contralateral delay activity, tCDA) was elicited over primary somatosensory cortex contralateral to the relevant hand. The amplitude of this component increased with memory load and was sensitive to individual limitations in memory capacity, suggesting that the tCDA reflects the maintenance of tactile information in somatosensory working memory. The tCDA was preceded by a transient negativity (N2cc component) with a similar contralateral scalp distribution, which is likely to reflect selection of task-relevant tactile stimuli at the encoding stage. The temporal sequence of N2cc and tCDA components mirrors previous observations from ERP studies of working memory in vision. The finding that the sustained somatosensory delay period activity varies as a function of memory load supports a sensory recruitment model for spatial working memory in touch. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  15. Effect of epidural 0.25% bupivacaine on somatosensory evoked potentials to dermatomal stimulation

    DEFF Research Database (Denmark)

    Lund, C; Hansen, O B; Kehlet, H

    1989-01-01

    The effect of lumbar epidural analgesia with similar volumes (about 25 ml) of 0.25% and 0.5% bupivacaine on early (less than 0.5 seconds) somatosensory evoked potentials (SEPs) to electrical stimulation of the S1, L1, and T10 dermatomes was examined in two groups of ten patients. Level of sensory...

  16. Effects of etidocaine administered epidurally on changes in somatosensory evoked potentials after dermatomal stimulation

    DEFF Research Database (Denmark)

    Lund, C; Hansen, O B; Kehlet, H

    1991-01-01

    The effect of lumbar epidural anesthesia with similar volumes (approximately 20 ml) of 1% and 1.5% etidocaine on early (less than 0.5 seconds) somatosensory evoked potentials (SEPs) to electrical stimulation of the S1, L1, and T10 dermatomes was examined in two groups of ten patients...

  17. The Role of Attention in Somatosensory Processing: A Multi-Trait, Multi-Method Analysis

    Science.gov (United States)

    Wodka, Ericka L.; Puts, Nicolaas A. J.; Mahone, E. Mark; Edden, Richard A. E.; Tommerdahl, Mark; Mostofsky, Stewart H.

    2016-01-01

    Sensory processing abnormalities in autism have largely been described by parent report. This study used a multi-method (parent-report and measurement), multi-trait (tactile sensitivity and attention) design to evaluate somatosensory processing in ASD. Results showed multiple significant within-method (e.g., parent report of different…

  18. Dermatomal Organization of SI Leg Representation in Humans: Revising the Somatosensory Homunculus.

    Science.gov (United States)

    Dietrich, Caroline; Blume, Kathrin R; Franz, Marcel; Huonker, Ralph; Carl, Maria; Preißler, Sandra; Hofmann, Gunther O; Miltner, Wolfgang H R; Weiss, Thomas

    2017-09-01

    Penfield and Rasmussen's homunculus is the valid map of the neural body representation of nearly each textbook of biology, physiology, and neuroscience. The somatosensory homunculus places the foot representation on the mesial surface of the postcentral gyrus followed by the representations of the lower leg and the thigh in superio-lateral direction. However, this strong homuncular organization contradicts the "dermatomal" organization of spinal nerves. We used somatosensory-evoked magnetic fields and source analysis to study the leg's neural representation in the primary somatosensory cortex (SI). We show that the representation of the back of the thigh is located inferior to the foot's representation in SI whereas the front of the thigh is located laterally to the foot's representation. This observation indicates that the localization of the leg in SI rather follows the dermatomal organization of spinal nerves than the typical map of neighboring body parts as depicted in Penfield and Rasmussen's illustration of the somatosensory homunculus. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  19. Somatosensory impairment and its association with balance limitation in people with multiple sclerosis.

    Science.gov (United States)

    Jamali, Akram; Sadeghi-Demneh, Ebrahim; Fereshtenajad, Niloufar; Hillier, Susan

    2017-09-01

    Somatosensory impairments are common in multiple sclerosis. However, little data are available to characterize the nature and frequency of these problems in people with multiple sclerosis. To investigate the frequency of somatosensory impairments and identify any association with balance limitations in people with multiple sclerosis. The design was a prospective cross-sectional study, involving 82 people with multiple sclerosis and 30 healthy controls. Tactile and proprioceptive sensory acuity were measured using the Rivermead Assessment of Somatosensory Performance. Vibration duration was assessed using a tuning fork. Duration for the Timed Up and Go Test and reaching distance of the Functional Reach Test were measured to assess balance limitations. The normative range of sensory modalities was defined using cut-off points in the healthy participants. The multivariate linear regression was used to identify the significant predictors of balance in people with multiple sclerosis. Proprioceptive impairments (66.7%) were more common than tactile (60.8%) and vibration impairments (44.9%). Somatosensory impairments were more frequent in the lower limb (78.2%) than the upper limb (64.1%). All sensory modalities were significantly associated with the Timed Up and Go and Functional Reach tests (pmultiple sclerosis. These impairments are independent predictors of balance limitation. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Cross-modal refinement of visual performance after brief somatosensory deprivation in adult mice.

    Science.gov (United States)

    Teichert, Manuel; Isstas, Marcel; Wenig, Steven; Setz, Christoph; Lehmann, Konrad; Bolz, Jürgen

    2018-01-01

    It is well established that the congenital lack of one sensory modality enhances functionality in the spared senses. However, whether a late onset deprivation of one sense leads to such alterations is largely unknown. Here, we investigated whether a somatosensory deprivation induced by bilateral whisker removal affects visual acuity and contrast sensitivity in fully adult mice. Using the visual cortex-dependent visual water task, we found that a brief somatosensory deprivation markedly improved behavioral visual acuity and contrast sensitivity by about 40%. Determining these attributes of vision using periodic optical imaging of intrinsic signals in the same mice revealed that visual cortex responses elicited by weak visual stimuli were massively increased after somatosensory deprivation. Strikingly, comparison of visual acuity and contrast sensitivity values determined by the visual water task and intrinsic signal imaging revealed that these measurements were almost identical, even at the level of individual animals. In summary, our results suggest that a brief manipulation of somatosensory experience profoundly boosts visual cortex-dependent vision in adults. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  1. Stroking or Buzzing? : A Comparison of Somatosensory Touch Stimuli Using 7 Tesla fMRI

    NARCIS (Netherlands)

    Van der Zwaag, W.; Gruetter, Rolf; Martuzzi, Roberto

    2015-01-01

    Studying body representations in the brain helps us to understand how we humans relate to our own bodies. The in vivo mapping of the somatosensory cortex, where these representations are found, is greatly facilitated by the high spatial resolution and high sensitivity to brain activation available

  2. Evaluation of a post-analysis method for cumulative dose distribution in stereotactic body radiotherapy

    International Nuclear Information System (INIS)

    Imae, Toshikazu; Takenaka, Shigeharu; Saotome, Naoya

    2016-01-01

    The purpose of this study was to evaluate a post-analysis method for cumulative dose distribution in stereotactic body radiotherapy (SBRT) using volumetric modulated arc therapy (VMAT). VMAT is capable of acquiring respiratory signals derived from projection images and machine parameters based on machine logs during VMAT delivery. Dose distributions were reconstructed from the respiratory signals and machine parameters in the condition where respiratory signals were without division, divided into 4 and 10 phases. The dose distribution of each respiratory phase was calculated on the planned four-dimensional CT (4DCT). Summation of the dose distributions was carried out using deformable image registration (DIR), and cumulative dose distributions were compared with those of the corresponding plans. Without division, dose differences between cumulative distribution and plan were not significant. In the condition Where respiratory signals were divided, dose differences were observed over dose in cranial region and under dose in caudal region of planning target volume (PTV). Differences between 4 and 10 phases were not significant. The present method Was feasible for evaluating cumulative dose distribution in VMAT-SBRT using 4DCT and DIR. (author)

  3. A bivariate optimal replacement policy with cumulative repair cost ...

    Indian Academy of Sciences (India)

    Min-Tsai Lai

    Shock model; cumulative damage model; cumulative repair cost limit; preventive maintenance model. 1. Introduction. Most production systems are repaired or replaced when they have already failed. However, they may require much time and high expenses to repair a failed system, so maintaining a system to prevent ...

  4. 42 CFR 457.560 - Cumulative cost-sharing maximum.

    Science.gov (United States)

    2010-10-01

    ... State Plan Requirements: Enrollee Financial Responsibilities § 457.560 Cumulative cost-sharing maximum... similar cost-sharing charges that, in the aggregate, exceed 5 percent of a family's total income for the... 42 Public Health 4 2010-10-01 2010-10-01 false Cumulative cost-sharing maximum. 457.560 Section...

  5. Editorial The importance of cumulative meta-analyses and ...

    African Journals Online (AJOL)

    for research. Furthermore, ignoring clinical trial evidence of benefit is unethical and negatively impacts on public health. Cumulative meta-analyses have contributed substantially to ... a cumulative meta-analysis of the use of oral beta blockers for ... survival benefit, with only 3 522 patients randomised.1,2 However, clinical ...

  6. Forest Practice Rules and cumulative watershed impacts in California

    Science.gov (United States)

    L. M. Reid

    1999-01-01

    Response to the following questions, "As currently implemented, are existing California forest practice rules effective in preventing cumulative watershed impacts, including flooding?" and "What kind of measures might improve the effectiveness of forest practices rules for avoiding forestry-related cumulative watershed impacts

  7. Basic properties of somatosensory-evoked responses in the dorsal hippocampus of the rat

    Science.gov (United States)

    Bellistri, Elisa; Aguilar, Juan; Brotons-Mas, Jorge R; Foffani, Guglielmo; de la Prida, Liset Menendez

    2013-01-01

    The hippocampus is a pivotal structure for episodic memory function. This ability relies on the possibility of integrating different features of sensory stimuli with the spatio-temporal context in which they occur. While recent studies now suggest that somatosensory information is already processed by the hippocampus, the basic mechanisms still remain unexplored. Here, we used electrical stimulation of the paws, the whisker pad or the medial lemniscus to probe the somatosensory pathway to the hippocampus in the anaesthetized rat, and multisite electrodes, in combination with tetrode and intracellular recordings, to look at the properties of somatosensory hippocampal responses. We found that peripheral and lemniscal stimulation elicited small local field potential responses in the dorsal hippocampus about 35–40 ms post-stimulus. Current source density analysis established the local nature of these responses, revealing associated synaptic sinks that were consistently confined to the molecular layer (ML) of the dentate gyrus (DG), with less regular activation of the CA1 stratum lacunosum moleculare (SLM). A delayed (40–45 ms), potentially active, current source that outlasted the SLM sink was present in about 50% cases around the CA1 pyramidal cell layer. Somatosensory stimulation resulted in multi-unit firing increases in the majority of DG responses (79%), whereas multi-unit firing suppression was observed in the majority of CA1 responses (62%). Tetrode and intracellular recordings of individual cells confirmed different firing modulation in the DG and the CA1 region, and verified the active nature of both the early ML sink and delayed somatic CA1 source. Hippocampal responses to somatosensory stimuli were dependent on fluctuations in the strength and composition of synaptic inputs due to changes of the ongoing local (hippocampal) and distant (cortical) state. We conclude that somatosensory signals reach the hippocampus mainly from layer II entorhinal cortex to

  8. Involvement of human primary somatosensory cortex in vibrotactile detection depends on task demand.

    Science.gov (United States)

    Tamè, Luigi; Holmes, Nicholas P

    2016-09-01

    Detecting and discriminating sensory stimuli are fundamental functions of the nervous system. Electrophysiological and lesion studies suggest that macaque primary somatosensory cortex (SI) is critically involved in discriminating between stimuli, but is not required simply for detecting stimuli. By contrast, transcranial magnetic stimulation (TMS) studies in humans have shown near-complete disruption of somatosensory detection when a single pulse of TMS is delivered over SI. To address this discrepancy, we measured the sensitivity and decision criteria of participants detecting vibrotactile stimuli with individually-tailored fMRI-guided TMS over SI, over a control site not activated by vibrotactile stimuli (inferior parietal lobule, IPL), or away from the head (a no TMS condition). In a one-interval detection task, TMS increased participants' likelihood of reporting 'no' target present regardless of site, but TMS over SI also decreased detection sensitivity, and prevented improvement in tactile sensitivity over time. We then measured tactile thresholds in a series of two-interval forced-choice (2IFC) detection and discrimination tasks with lower dependence on response criteria and short-term memory load. We found that thresholds for detecting stimuli were comparable with TMS over SI and IPL, but TMS over SI specifically and significantly impaired frequency discrimination. We conclude that, in accordance with macaque studies, human SI is required for discriminating between tactile stimuli and for maintaining stimulus representations over time, or under high task demand, but may not be required for simple tactile detection. Studies on monkeys have suggested that the primary somatosensory cortex is responsible for discriminating between different vibrations on the fingertips, but not just for detecting these vibrations. However, similar studies in humans suggest that the somatosensory cortex is required both for detecting and discriminating between tactile stimuli. We

  9. Basic properties of somatosensory-evoked responses in the dorsal hippocampus of the rat.

    Science.gov (United States)

    Bellistri, Elisa; Aguilar, Juan; Brotons-Mas, Jorge R; Foffani, Guglielmo; de la Prida, Liset Menendez

    2013-05-15

    The hippocampus is a pivotal structure for episodic memory function. This ability relies on the possibility of integrating different features of sensory stimuli with the spatio-temporal context in which they occur. While recent studies now suggest that somatosensory information is already processed by the hippocampus, the basic mechanisms still remain unexplored. Here, we used electrical stimulation of the paws, the whisker pad or the medial lemniscus to probe the somatosensory pathway to the hippocampus in the anaesthetized rat, and multisite electrodes, in combination with tetrode and intracellular recordings, to look at the properties of somatosensory hippocampal responses. We found that peripheral and lemniscal stimulation elicited small local field potential responses in the dorsal hippocampus about 35-40 ms post-stimulus. Current source density analysis established the local nature of these responses, revealing associated synaptic sinks that were consistently confined to the molecular layer (ML) of the dentate gyrus (DG), with less regular activation of the CA1 stratum lacunosum moleculare (SLM). A delayed (40-45 ms), potentially active, current source that outlasted the SLM sink was present in about 50% cases around the CA1 pyramidal cell layer. Somatosensory stimulation resulted in multi-unit firing increases in the majority of DG responses (79%), whereas multi-unit firing suppression was observed in the majority of CA1 responses (62%). Tetrode and intracellular recordings of individual cells confirmed different firing modulation in the DG and the CA1 region, and verified the active nature of both the early ML sink and delayed somatic CA1 source. Hippocampal responses to somatosensory stimuli were dependent on fluctuations in the strength and composition of synaptic inputs due to changes of the ongoing local (hippocampal) and distant (cortical) state. We conclude that somatosensory signals reach the hippocampus mainly from layer II entorhinal cortex to

  10. High cumulants of conserved charges and their statistical uncertainties

    Science.gov (United States)

    Li-Zhu, Chen; Ye-Yin, Zhao; Xue, Pan; Zhi-Ming, Li; Yuan-Fang, Wu

    2017-10-01

    We study the influence of measured high cumulants of conserved charges on their associated statistical uncertainties in relativistic heavy-ion collisions. With a given number of events, the measured cumulants randomly fluctuate with an approximately normal distribution, while the estimated statistical uncertainties are found to be correlated with corresponding values of the obtained cumulants. Generally, with a given number of events, the larger the cumulants we measure, the larger the statistical uncertainties that are estimated. The error-weighted averaged cumulants are dependent on statistics. Despite this effect, however, it is found that the three sigma rule of thumb is still applicable when the statistics are above one million. Supported by NSFC (11405088, 11521064, 11647093), Major State Basic Research Development Program of China (2014CB845402) and Ministry of Science and Technology (MoST) (2016YFE0104800)

  11. Inhibitory rTMS applied on somatosensory cortex in Wilson's disease patients with hand dystonia.

    Science.gov (United States)

    Lozeron, Pierre; Poujois, Aurélia; Meppiel, Elodie; Masmoudi, Sana; Magnan, Thierry Peron; Vicaut, Eric; Houdart, Emmanuel; Guichard, Jean-Pierre; Trocello, Jean-Marc; Woimant, France; Kubis, Nathalie

    2017-10-01

    Hand dystonia is a common complication of Wilson's disease (WD), responsible for handwriting difficulties and disability. Alteration of sensorimotor integration and overactivity of the somatosensory cortex have been demonstrated in dystonia. This study investigated the immediate after effect of an inhibitory repetitive transcranial magnetic stimulation (rTMS) applied over the somatosensory cortex on the writing function in WD patients with hand dystonia. We performed a pilot prospective randomized double-blind sham-controlled crossover rTMS study. A 20-min 1-Hz rTMS session, stereotaxically guided, was applied over the left somatosensory cortex in 13 WD patients with right dystonic writer's cramp. After 3 days, each patient was crossed-over to the alternative treatment. Patients were clinically evaluated before and immediately after each rTMS session with the Unified Wilson's Disease rating scale (UWDRS), the Writers' Cramp Rating Scale (WCRS), a specifically designed scale for handwriting difficulties in Wilson's disease patients (FAR, flow, accuracy, and rhythmicity evaluation), and a visual analog scale (VAS) for handwriting discomfort. No significant change in UWDRS, WCRS, VAS, or FAR scores was observed in patients treated with somatosensory inhibitory rTMS compared to the sham protocol. The FAR negatively correlated with UWDRS (r = -0.6; P = 0.02), but not with the WCRS score, disease duration, MRI diffusion lesions, or with atrophy scores. In our experimental conditions, a single inhibitory rTMS session applied over somatosensory cortex did not improve dystonic writer cramp in WD patients.

  12. Functional deficits in carpal tunnel syndrome reflect reorganization of primary somatosensory cortex.

    Science.gov (United States)

    Maeda, Yumi; Kettner, Norman; Holden, Jameson; Lee, Jeungchan; Kim, Jieun; Cina, Stephen; Malatesta, Cristina; Gerber, Jessica; McManus, Claire; Im, Jaehyun; Libby, Alexandra; Mezzacappa, Pia; Morse, Leslie R; Park, Kyungmo; Audette, Joseph; Tommerdahl, Mark; Napadow, Vitaly

    2014-06-01

    Carpal tunnel syndrome, a median nerve entrapment neuropathy, is characterized by sensorimotor deficits. Recent reports have shown that this syndrome is also characterized by functional and structural neuroplasticity in the primary somatosensory cortex of the brain. However, the linkage between this neuroplasticity and the functional deficits in carpal tunnel syndrome is unknown. Sixty-three subjects with carpal tunnel syndrome aged 20-60 years and 28 age- and sex-matched healthy control subjects were evaluated with event-related functional magnetic resonance imaging at 3 T while vibrotactile stimulation was delivered to median nerve innervated (second and third) and ulnar nerve innervated (fifth) digits. For each subject, the interdigit cortical separation distance for each digit's contralateral primary somatosensory cortex representation was assessed. We also evaluated fine motor skill performance using a previously validated psychomotor performance test (maximum voluntary contraction and visuomotor pinch/release testing) and tactile discrimination capacity using a four-finger forced choice response test. These biobehavioural and clinical metrics were evaluated and correlated with the second/third interdigit cortical separation distance. Compared with healthy control subjects, subjects with carpal tunnel syndrome demonstrated reduced second/third interdigit cortical separation distance (P somatosensory cortex, corroborating our previous preliminary multi-modal neuroimaging findings. For psychomotor performance testing, subjects with carpal tunnel syndrome demonstrated reduced maximum voluntary contraction pinch strength (P somatosensory cortex was associated with worse symptomatology (particularly paraesthesia), reduced fine motor skill performance, and worse sensory discrimination accuracy for median nerve innervated digits. In conclusion, primary somatosensory cortex neuroplasticity for median nerve innervated digits in carpal tunnel syndrome is indeed

  13. Expectation violation and attention to pain jointly modulate neural gain in somatosensory cortex.

    Science.gov (United States)

    Fardo, Francesca; Auksztulewicz, Ryszard; Allen, Micah; Dietz, Martin J; Roepstorff, Andreas; Friston, Karl J

    2017-06-01

    The neural processing and experience of pain are influenced by both expectations and attention. For example, the amplitude of event-related pain responses is enhanced by both novel and unexpected pain, and by moving the focus of attention towards a painful stimulus. Under predictive coding, this congruence can be explained by appeal to a precision-weighting mechanism, which mediates bottom-up and top-down attentional processes by modulating the influence of feedforward and feedback signals throughout the cortical hierarchy. The influence of expectation and attention on pain processing can be mapped onto changes in effective connectivity between or within specific neuronal populations, using a canonical microcircuit (CMC) model of hierarchical processing. We thus implemented a CMC within dynamic causal modelling for magnetoencephalography in human subjects, to investigate how expectation violation and attention to pain modulate intrinsic (within-source) and extrinsic (between-source) connectivity in the somatosensory hierarchy. This enabled us to establish whether both expectancy and attentional processes are mediated by a similar precision-encoding mechanism within a network of somatosensory, frontal and parietal sources. We found that both unexpected and attended pain modulated the gain of superficial pyramidal cells in primary and secondary somatosensory cortex. This modulation occurred in the context of increased lateralized recurrent connectivity between somatosensory and fronto-parietal sources, driven by unexpected painful occurrences. Finally, the strength of effective connectivity parameters in S1, S2 and IFG predicted individual differences in subjective pain modulation ratings. Our findings suggest that neuromodulatory gain control in the somatosensory hierarchy underlies the influence of both expectation violation and attention on cortical processing and pain perception. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  14. Influence of body position on cortical pain-related somatosensory processing: an ERP study.

    Directory of Open Access Journals (Sweden)

    Chiara Spironelli

    Full Text Available BACKGROUND: Despite the consistent information available on the physiological changes induced by head down bed rest, a condition which simulates space microgravity, our knowledge on the possible perceptual-cortical alterations is still poor. The present study investigated the effects of 2-h head-down bed rest on subjective and cortical responses elicited by electrical, pain-related somatosensory stimulation. METHODOLOGY/PRINCIPAL FINDINGS: Twenty male subjects were randomly assigned to two groups, head-down bed rest (BR or sitting control condition. Starting from individual electrical thresholds, Somatosensory Evoked Potentials were elicited by electrical stimuli administered randomly to the left wrist and divided into four conditions: control painless condition, electrical pain threshold, 30% above pain threshold, 30% below pain threshold. Subjective pain ratings collected during the EEG session showed significantly reduced pain perception in BR compared to Control group. Statistical analysis on four electrode clusters and sLORETA source analysis revealed, in sitting controls, a P1 component (40-50 ms in the right somatosensory cortex, whereas it was bilateral and differently located in BR group. Controls' N1 (80-90 ms had widespread right hemisphere activation, involving also anterior cingulate, whereas BR group showed primary somatosensory cortex activation. The P2 (190-220 ms was larger in left-central locations of Controls compared with BR group. CONCLUSIONS/SIGNIFICANCE: Head-down bed rest was associated to an overall decrease of pain sensitivity and an altered pain network also outside the primary somatosensory cortex. Results have implications not only for astronauts' health and spaceflight risks, but also for the clinical aspects of pain detection in bedridden patients at risk of fatal undetected complications.

  15. Rehabilitation: Periodic somatosensory stimulation increases arterial baroreflex sensitivity in chronic heart failure patients.

    Science.gov (United States)

    Gademan, Maaike G J; Sun, Yiping; Han, Liming; Valk, Vanessa J; Schalij, Martin J; van Exel, Henk J; Lucas, Carolien M H B; Maan, Arie C; Verwey, Harriette F; van de Vooren, Hedde; Pinna, Gian D; Maestri, Roberto; La Rovere, Maria Teresa; van der Wall, Ernst E; Swenne, Cees A

    2011-10-20

    One of the beneficial effects of exercise training in chronic heart failure (CHF) is an improvement in baroreflex sensitivity (BRS), a prognostic index in CHF. In our hypothesis-generating study we propose that at least part of this effect is mediated by neural afferent information, and more specifically, by exercise-induced somatosensory nerve traffic. To compare the effects of periodic electrical somatosensory stimulation on BRS in patients with CHF with the effects of exercise training and with usual care. We compared in stable CHF patients the effect of transcutaneous electrical nerve stimulation (TENS, N = 23, LVEF 30 ± 9%) with the effects of bicycle exercise training (EXTR, N = 20, LVEF 32 ± 7%). To mimic exercise-associated somatosensory ergoreceptor stimulation, we applied periodic (2/s, marching pace) burst TENS to both feet. TENS and EXTR sessions were held during two successive days. BRS, measured prior to the first intervention session and one day after the second intervention session, increased by 28% from 3.07 ± 2.06 to 4.24 ± 2.61 ms/mmHg in the TENS group, but did not change in the EXTR group (baseline: 3.37 ± 2.53 ms/mmHg; effect: 3.26 ± 2.54 ms/mmHg) (P(TENS vs EXTR) = 0.02). Heart rate and systolic blood pressure did not change in either group. We demonstrated that periodic somatosensory input alone is sufficient and efficient in increasing BRS in CHF patients. This concept constitutes a basis for studies towards more effective exercise training regimens in the diseased/impaired, in whom training aimed at BRS improvement should possibly focus more on the somatosensory aspect. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  16. Longhi Games, Internal Reservoirs, and Cumulate Porosity

    Science.gov (United States)

    Morse, S. A.

    2009-05-01

    Fe in plagioclase at an early age, T-rollers (or not) on the Di-Trid boundary in Fo-Di-Sil, the mantle solidus, origins of anorthosites, esoteric uses of Schreinemakers rules and many more topics are all fresh and pleasant memories of John Longhi's prolific and creative work. The Fram-Longhi experimental effect of pressure on plagioclase partitioning with liquid in mafic rocks became essential to an understanding of multiphase Rayleigh fractionation of plagioclase in big layered intrusions. Only by using the pressure effect could I find a good equation through the data for the Kiglapait intrusion, and that result among others required the existence with probability 1.0 of an internal reservoir (Morse, JPet 2008). Knowledge of cumulate porosity is a crucial key to the understanding of layered igneous rocks. We seek both the initial (inverse packing fraction) and residual porosity to find the time and process path from sedimentation to solidification. In the Kiglapait Lower Zone we have a robust estimate of mean residual porosity from the modes of the excluded phases augite, oxides, sulfide, and apatite. To this we apply the maximum variance of plagioclase composition (the An range) to find an algorithm that extends through the Upper Zone and to other intrusions. Of great importance is that all these measurements were made in grain mounts concentrated from typically about 200 g of core or hand specimen, hence the represented sample volume is thousands of times greater than for a thin section. The resulting distribution and scatter of the An range is novel and remarkable. It is V-shaped in the logarithmic representation of stratigraphic height, running from about 20 mole % at both ends (base to top of the Layered Series) to near-zero at 99 PCS. The intercept of the porosity-An range relation gives An range = 3.5 % at zero residual porosity. Petrographic analysis reveals that for PCS less than 95 and greater than 99.9, the An range is intrinsic, i.e. pre-cumulus, for

  17. An analysis of cumulative risks based on biomonitoring data for six phthalates using the Maximum Cumulative Ratio

    Science.gov (United States)

    The Maximum Cumulative Ratio (MCR) quantifies the degree to which a single chemical drives the cumulative risk of an individual exposed to multiple chemicals. Phthalates are a class of chemicals with ubiquitous exposures in the general population that have the potential to cause ...

  18. Cumulants in perturbation expansions for non-equilibrium field theory

    International Nuclear Information System (INIS)

    Fauser, R.

    1995-11-01

    The formulation of perturbation expansions for a quantum field theory of strongly interacting systems in a general non-equilibrium state is discussed. Non-vanishing initial correlations are included in the formulation of the perturbation expansion in terms of cumulants. The cumulants are shown to be the suitable candidate for summing up the perturbation expansion. Also a linked-cluster theorem for the perturbation series with cumulants is presented. Finally a generating functional of the perturbation series with initial correlations is studied. We apply the methods to a simple model of a fermion-boson system. (orig.)

  19. A quantile-based study of cumulative residual Tsallis entropy measures

    Science.gov (United States)

    Sunoj, S. M.; Krishnan, Aswathy S.; Sankaran, P. G.

    2018-03-01

    In the present paper we introduce a quantile-based cumulative residual Tsallis entropy (CRTE) and quantile-based CRTE for order statistics. Unlike the cumulative residual Tsallis entropy measures in the distribution function approach due to Sati and Gupta (2015) and Rajesh and Sunoj (2016) respectively, the corresponding quantile versions possess some unique properties. In many applied works there do not have any tractable distribution functions while the quantile function exists and in such cases the proposed measures become more useful in measuring uncertainty of random variables. We obtain some characterizations for distributions based on the quantile versions of CRTE and derive certain bounds. We also study various properties of quantile-based CRTE for order statistics.

  20. The primary somatosensory cortex and the insula contribute differently to the processing of transient and sustained nociceptive and non-nociceptive somatosensory inputs.

    Science.gov (United States)

    Hu, Li; Zhang, Li; Chen, Rui; Yu, Hongbo; Li, Hong; Mouraux, André

    2015-11-01

    Transient nociceptive stimuli elicit consistent brain responses in the primary and secondary somatosensory cortices (S1, S2), the insula and the anterior and mid-cingulate cortex (ACC/MCC). However, the functional significance of these responses, especially their relationship with sustained pain perception, remains largely unknown. Here, using functional magnetic resonance imaging, we characterize the differential involvement of these brain regions in the processing of sustained nociceptive and non-nociceptive somatosensory input. By comparing the spatial patterns of activity elicited by transient (0.5 ms) and long-lasting (15 and 30 s) stimuli selectively activating nociceptive or non-nociceptive afferents, we found that the contralateral S1 responded more strongly to the onset of non-nociceptive stimulation as compared to the onset of nociceptive stimulation and the sustained phases of nociceptive and non-nociceptive stimulation. Similarly, the anterior insula responded more strongly to the onset of nociceptive stimulation as compared to the onset of non-nociceptive stimulation and the sustained phases of nociceptive and non-nociceptive stimulation. This suggests that S1 is specifically sensitive to changes in incoming non-nociceptive input, whereas the anterior insula is specifically sensitive to changes in incoming nociceptive input. Second, we found that the MCC responded more strongly to the onsets as compared to the sustained phases of both nociceptive and non-nociceptive stimulation, suggesting that it could be involved in the detection of change regardless of sensory modality. Finally, the posterior insula and S2 responded maximally during the sustained phase of non-nociceptive stimulation but not nociceptive stimulation, suggesting that these regions are preferentially involved in processing non-nociceptive somatosensory input. © 2015 Wiley Periodicals, Inc.

  1. The somatosensory link in fibromyalgia: functional connectivity of the primary somatosensory cortex is altered by sustained pain and is associated with clinical/autonomic dysfunction.

    Science.gov (United States)

    Kim, Jieun; Loggia, Marco L; Cahalan, Christine M; Harris, Richard E; Beissner, Florian; Garcia, Ronald G; Kim, Hyungjun; Wasan, Ajay D; Edwards, Robert R; Napadow, Vitaly

    2015-05-01

    Fibromyalgia (FM) is a chronic functional pain syndrome characterized by widespread pain, significant pain catastrophizing, sympathovagal dysfunction, and amplified temporal summation for evoked pain. While several studies have demonstrated altered resting brain connectivity in FM, studies have not specifically probed the somatosensory system and its role in both somatic and nonsomatic FM symptoms. Our objective was to evaluate resting primary somatosensory cortex (S1) connectivity and to explore how sustained, evoked deep tissue pain modulates this connectivity. We acquired functional magnetic resonance imaging and electrocardiography data on FM patients and healthy controls during rest (the rest phase) and during sustained mechanical pressure-induced pain over the lower leg (the pain phase). Functional connectivity associated with different S1 subregions was calculated, while S1(leg) connectivity (representation of the leg in the primary somatosensory cortex) was contrasted between the rest phase and the pain phase and was correlated with clinically relevant measures in FM. During the rest phase, FM patients showed decreased connectivity between multiple ipsilateral and cross-hemispheric S1 subregions, which was correlated with clinical pain severity. Compared to the rest phase, the pain phase produced increased S1(leg) connectivity to the bilateral anterior insula in FM patients, but not in healthy controls. Moreover, in FM patients, sustained pain-altered S1(leg) connectivity to the anterior insula was correlated with clinical/behavioral pain measures and autonomic responses. Our study demonstrates that both somatic and nonsomatic dysfunction in FM, including clinical pain, pain catastrophizing, autonomic dysfunction, and amplified temporal summation, are closely linked with the degree to which evoked deep tissue pain alters S1 connectivity to salience/affective pain-processing regions. Additionally, diminished connectivity between S1 subregions during the rest

  2. Spatial segregation of somato-sensory and pain activations in the human operculo-insular cortex.

    Science.gov (United States)

    Mazzola, Laure; Faillenot, Isabelle; Barral, Fabrice-Guy; Mauguière, François; Peyron, Roland

    2012-03-01

    The role of operculo-insular region in the processing of somato-sensory inputs, painful or not, is now well established. However, available maps from previous literature show a substantial overlap of cortical areas activated by these stimuli, and the region referred to as the "secondary somatosensory area (SII)" is widely distributed in the parietal operculum. Differentiating SII from posterior insula cortex, which is anatomically contiguous, is not easy, explaining why the "operculo-insular" label has been introduced to describe activations by somatosensory stimuli in this cortical region. Based on the recent cyto-architectural parcellation of the human insular/SII cortices (Eickhoff et al., 2006, Kurth et al., 2010), the present study investigates with functional MRI (fMRI), whether these structural subdivisions could subserve distinct aspects of discriminative somato-sensory functions, including pain. Responses to five types of stimuli applied on the left hand of 25 healthy volunteers were considered: i) tactile stimuli; ii) passive movements; iii) innocuous cold stimuli; iv) non-noxious warm and v) heat pain. Our results show different patterns of activation depending on the type of somato-sensory stimulation. The posterior part of SII (OP1 area), contralateral to stimuli, was the only sub-region activated by all type of stimuli and might therefore be considered as a common cortical target for different types of somato-sensory inputs. Proprioceptive stimulation by passive finger movements activated the posterior part of SII (OP1 sub-region) bilaterally and the contralateral median part of insula (PreCG and MSG). Innocuous cooling activated the contralateral posterior part of SII (OP1) and the dorsal posterior and median part of insula (OP2, PostCG). Pain stimuli induced the most widespread and intense activation that was bilateral in SII (OP1, OP4) and distributed to all sub-regions of contralateral insula (except OP2) and to the anterior part of the

  3. Effects of age on negative BOLD signal changes in the primary somatosensory cortex.

    Science.gov (United States)

    Gröschel, Sonja; Sohns, Jan Martin; Schmidt-Samoa, Carsten; Baudewig, Jürgen; Becker, Lars; Dechent, Peter; Kastrup, Andreas

    2013-05-01

    In addition to a contralateral activation of the primary and secondary somatosensory cortices, peripheral sensory stimulation has been shown to elicit responses in the ipsilateral primary somatosensory cortex (SI). In particular, evidence is accumulating that processes of interhemispheric inhibition as depicted by negative blood oxygenation level dependent (BOLD) signal changes are part of somatosensory processes. The aim of the study was to analyze age-related differences in patterns of cerebral activation in the somatosensory system in general and processes of interhemispheric inhibition in particular. For this, a functional magnetic resonance imaging (fMRI) study was performed including 14 younger (mean age 23.3±0.9years) and 13 healthy older participants (mean age 73.2±8.3years). All subjects were scanned during peripheral electrical median nerve stimulation (40Hz) to obtain BOLD responses in the somatosensory system. Moreover, the individual current perception threshold (CPT) as a quantitative measure of sensory function was determined in a separate psychophysical testing. Significant increases in BOLD signal across the entire group could be measured within the contralateral SI, in the bilateral secondary somatosensory cortex (SII), the contralateral supplementary motor area and the insula. Negative BOLD signal changes were delineated in ipsilateral SI/MI as well as in the ipsilateral thalamus and basal ganglia. After comparing the two groups, only the cortical deactivation in ipsilateral SI in the early stimulation phase as well as the activation in contralateral SI and SII in the late stimulation block remained as statistically significant differences between the two groups. The psychophysical experiments yielded a significant age-dependent effect of CPT change with less difference in the older group which is in line with the significantly smaller alterations in maximal BOLD signal change in the contra- and ipsilateral SI found between the two groups

  4. Ehlers-Danlos Syndrome, Hypermobility Type: Impact of Somatosensory Orthoses on Postural Control (A Pilot Study

    Directory of Open Access Journals (Sweden)

    Emma G. Dupuy

    2017-06-01

    Full Text Available Elhers-Danlos syndrome (EDS is the clinical manifestation of connective tissue disorders, and comprises several clinical forms with no specific symptoms and selective medical examinations which result in a delay in diagnosis of about 10 years. The EDS hypermobility type (hEDS is characterized by generalized joint hypermobility, variable skin hyperextensibility and impaired proprioception. Since somatosensory processing and multisensory integration are crucial for both perception and action, we put forth the hypothesis that somatosensory deficits in hEDS patients may lead, among other clinical symptoms, to misperception of verticality and postural instability. Therefore, the purpose of this study was twofold: (i to assess the impact of somatosensory deficit on subjective visual vertical (SVV and postural stability; and (ii to quantify the effect of wearing somatosensory orthoses (i.e., compressive garments and insoles on postural stability. Six hEDS patients and six age- and gender-matched controls underwent a SVV (sitting, standing, lying on the right side evaluation and a postural control evaluation on a force platform (Synapsys, with or without visual information (eyes open (EO/eyes closed (EC. These two latter conditions performed either without orthoses, or with compression garments (CG, or insoles, or both. Results showed that patients did not exhibit a substantial perceived tilt of the visual vertical in the direction of the body tilt (Aubert effect as did the control subjects. Interestingly, such differential effects were only apparent when the rod was initially positioned to the left of the vertical axis (opposite the longitudinal body axis. In addition, patients showed greater postural instability (sway area than the controls. The removal of vision exacerbated this instability, especially in the mediolateral (ML direction. The wearing of orthoses improved postural stability, especially in the eyes-closed condition, with a particularly

  5. Ehlers-Danlos Syndrome, Hypermobility Type: Impact of Somatosensory Orthoses on Postural Control (A Pilot Study)

    Science.gov (United States)

    Dupuy, Emma G.; Leconte, Pascale; Vlamynck, Elodie; Sultan, Audrey; Chesneau, Christophe; Denise, Pierre; Besnard, Stéphane; Bienvenu, Boris; Decker, Leslie M.

    2017-01-01

    Elhers-Danlos syndrome (EDS) is the clinical manifestation of connective tissue disorders, and comprises several clinical forms with no specific symptoms and selective medical examinations which result in a delay in diagnosis of about 10 years. The EDS hypermobility type (hEDS) is characterized by generalized joint hypermobility, variable skin hyperextensibility and impaired proprioception. Since somatosensory processing and multisensory integration are crucial for both perception and action, we put forth the hypothesis that somatosensory deficits in hEDS patients may lead, among other clinical symptoms, to misperception of verticality and postural instability. Therefore, the purpose of this study was twofold: (i) to assess the impact of somatosensory deficit on subjective visual vertical (SVV) and postural stability; and (ii) to quantify the effect of wearing somatosensory orthoses (i.e., compressive garments and insoles) on postural stability. Six hEDS patients and six age- and gender-matched controls underwent a SVV (sitting, standing, lying on the right side) evaluation and a postural control evaluation on a force platform (Synapsys), with or without visual information (eyes open (EO)/eyes closed (EC)). These two latter conditions performed either without orthoses, or with compression garments (CG), or insoles, or both. Results showed that patients did not exhibit a substantial perceived tilt of the visual vertical in the direction of the body tilt (Aubert effect) as did the control subjects. Interestingly, such differential effects were only apparent when the rod was initially positioned to the left of the vertical axis (opposite the longitudinal body axis). In addition, patients showed greater postural instability (sway area) than the controls. The removal of vision exacerbated this instability, especially in the mediolateral (ML) direction. The wearing of orthoses improved postural stability, especially in the eyes-closed condition, with a particularly

  6. Individuals with a vestibular-related disorder use a somatosensory-dominant strategy for postural orientation after inclined stance.

    Science.gov (United States)

    Chong, R; Berl, B; Cook, B; Turner, P; Walker, K

    2017-06-01

    The visual, somatosensory, and vestibular systems are critical for establishing a sensorimotor set for postural control and orientation. The goal of this study was to assess how individuals with a vestibular-related disorder keep their balance following prolonged stance on an inclined surface. We hypothesize that subjects will show greater reliance on the somatosensory system than age-matched controls as inferred by the presence of a forward postural lean aftereffect following the inclined stance (i.e., a positive response). The results revealed an underlying somatosensory-dominant strategy for postural control in the vestibular group: 100% of the subjects tested positive compared to 58% in the control group (P=.006). Individuals with a vestibular-related disorder use a somatosensory-dominant strategy for postural orientation following prolonged inclined stance. The implications for the management of this population are discussed. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Determinants of mobility and self-care in older people with stroke: importance of somatosensory and perceptual functions.

    Science.gov (United States)

    Welmer, Anna-Karin; von Arbin, Magnus; Murray, Veronica; Holmqvist, Lotta Widén; Sommerfeld, Disa K

    2007-12-01

    Somatosensory as well as mental impairments are easily overlooked after acute stroke. Furthermore, their associations with activity limitations are not fully understood. The purpose of this study was to examine this association and whether the assessment of somatosensory functions will provide information on perceptual functions after acute stroke. In 115 subjects who were > or =65 years of age, the following parameters were assessed 5 days after stroke: somatosensory (touch and proprioceptive), perceptual, and cognitive functions; depressive symptoms; mobility; and self-care. Multivariate analyses showed that normal proprioceptive function was significantly associated with better mobility. Normal perceptual and touch functions were significantly associated with better self-care. Subjects with normal proprioceptive function were 8.6 times as likely to have normal perceptual function as subjects with proprioceptive impairment. Somatosensory and perceptual functions were significantly associated with subjects' activity levels. Normal proprioceptive function also might indicate normal perceptual function.

  8. Cortical somatosensory-evoked potentials during spine surgery in patients with neuromuscular and idiopathic scoliosis under propofol-remifentanil anaesthesia

    NARCIS (Netherlands)

    Hermanns, H.; Lipfert, P.; Meier, S.; Jetzek-Zader, M.; Krauspe, R.; Stevens, M. F.

    2007-01-01

    BACKGROUND: Intraoperative monitoring of the spinal cord via cortical somatosensory-evoked potentials (SSEP) is a routine during spinal surgery. However, especially in neuromuscular scoliosis, the reliability of cortical SSEP has been questioned. Therefore, we compared the feasibility of cortical

  9. Metaphorically Feeling: Comprehending Textural Metaphors Activates Somatosensory Cortex

    Science.gov (United States)

    Lacey, Simon; Stilla, Randall; Sathian, K.

    2012-01-01

    Conceptual metaphor theory suggests that knowledge is structured around metaphorical mappings derived from physical experience. Segregated processing of object properties in sensory cortex allows testing of the hypothesis that metaphor processing recruits activity in domain-specific sensory cortex. Using functional magnetic resonance imaging…

  10. The strychnine-like action of curare and related compounds on the somatosensory evoked response of the rat cortex

    Science.gov (United States)

    Bhargava, V. K.; Meldrum, B. S.

    1969-01-01

    1. Drugs were applied to the cerebral cortex of rats anaesthetized with pentobarbitone and changes measured in the somatosensory primary evoked response. 2. Computer-derived averages of thirty-two consecutive responses yielded stable and consistent measurements of the potential changes comprising the evoked response, and comparable records from the opposite (non-drug treated) cortex provided an essential control for systemic actions of the drug. 3. The modifications produced by curare and strychnine were indistinguishable. The first positive wave (peak latency 7 msec) was unaltered; the second positive wave (peak latency 11·5 msec) was variably enhanced, and the first and second negative waves (peak latencies 16 and 40 msec) were replaced by a much larger negative wave (peak latency 22 msec). 4. The time of onset of the effect on the negative waves and the maximal amplitude attained by the abnormal negative wave were related to the log concentration of the drug used. Curare is approximately 10 times more potent than strychnine. 5. Toxiferine I, di-allylnortoxiferine and atropine also produced this effect but were less potent than strychnine. 6. Succinylcholine, dihydro-β-erythroidine and gallamine triethiodide did not produce this effect (in concentrations up to 10-3M). 7. The observations are consistent with an action of curare and strychnine on an intracortical cholinergic inhibitory system, but other possibilities including a “non-specific excitatory action” cannot be excluded. PMID:5824927

  11. Cumulative radiation exposure in children with cystic fibrosis.

    LENUS (Irish Health Repository)

    O'Reilly, R

    2010-02-01

    This retrospective study calculated the cumulative radiation dose for children with cystic fibrosis (CF) attending a tertiary CF centre. Information on 77 children with a mean age of 9.5 years, a follow up time of 658 person years and 1757 studies including 1485 chest radiographs, 215 abdominal radiographs and 57 computed tomography (CT) scans, of which 51 were thoracic CT scans, were analysed. The average cumulative radiation dose was 6.2 (0.04-25) mSv per CF patient. Cumulative radiation dose increased with increasing age and number of CT scans and was greater in children who presented with meconium ileus. No correlation was identified between cumulative radiation dose and either lung function or patient microbiology cultures. Radiation carries a risk of malignancy and children are particularly susceptible. Every effort must be made to avoid unnecessary radiation exposure in these patients whose life expectancy is increasing.

  12. Cumulative Environmental Impacts: Science and Policy to Protect Communities.

    Science.gov (United States)

    Solomon, Gina M; Morello-Frosch, Rachel; Zeise, Lauren; Faust, John B

    2016-01-01

    Many communities are located near multiple sources of pollution, including current and former industrial sites, major roadways, and agricultural operations. Populations in such locations are predominantly low-income, with a large percentage of minorities and non-English speakers. These communities face challenges that can affect the health of their residents, including limited access to health care, a shortage of grocery stores, poor housing quality, and a lack of parks and open spaces. Environmental exposures may interact with social stressors, thereby worsening health outcomes. Age, genetic characteristics, and preexisting health conditions increase the risk of adverse health effects from exposure to pollutants. There are existing approaches for characterizing cumulative exposures, cumulative risks, and cumulative health impacts. Although such approaches have merit, they also have significant constraints. New developments in exposure monitoring, mapping, toxicology, and epidemiology, especially when informed by community participation, have the potential to advance the science on cumulative impacts and to improve decision making.

  13. Characterization of pore volume of cumulative water injection distribution

    Directory of Open Access Journals (Sweden)

    Guoqing Feng

    2015-06-01

    Full Text Available Pore volume of Cumulative water injection is one of the factors for evaluating water flood effect in a water flood oil field. In previous study, there were limited lab studies for evaluating oil displacement efficiency. A method to characterize the distribution of pore volume of cumulative water injection is proposed in this paper, and it is verified by a five-spot water flooding streamline simulation model. The logarithmic relation between pore volume of cumulative water injection and water saturation is established by regression. An inflection point and limit point of cumulative water injection pore volume are identified. Current simulation model indicates inflection point appears after 2–5 pore volume (PV injection, and limit point appears after 15–25 PV injection. Both inflection and limit point vary in different regions of reservoir.

  14. Online Scheduling in Manufacturing A Cumulative Delay Approach

    CERN Document Server

    Suwa, Haruhiko

    2013-01-01

    Online scheduling is recognized as the crucial decision-making process of production control at a phase of “being in production" according to the released shop floor schedule. Online scheduling can be also considered as one of key enablers to realize prompt capable-to-promise as well as available-to-promise to customers along with reducing production lead times under recent globalized competitive markets. Online Scheduling in Manufacturing introduces new approaches to online scheduling based on a concept of cumulative delay. The cumulative delay is regarded as consolidated information of uncertainties under a dynamic environment in manufacturing and can be collected constantly without much effort at any points in time during a schedule execution. In this approach, the cumulative delay of the schedule has the important role of a criterion for making a decision whether or not a schedule revision is carried out. The cumulative delay approach to trigger schedule revisions has the following capabilities for the ...

  15. Pesticide Cumulative Risk Assessment: Framework for Screening Analysis

    Science.gov (United States)

    This document provides guidance on how to screen groups of pesticides for cumulative evaluation using a two-step approach: begin with evaluation of available toxicological information and, if necessary, follow up with a risk-based screening approach.

  16. Peer tutors as learning and teaching partners: a cumulative ...

    African Journals Online (AJOL)

    ... paper explores the kinds of development in tutors' thinking and action that are possible when training and development is theoretically informed, coherent, and oriented towards improving practice. Keywords: academic development, academic literacies, cumulative learning, higher education, peer tutoring, writing centres.

  17. Some Characterization Results on Dynamic Cumulative Residual Tsallis Entropy

    Directory of Open Access Journals (Sweden)

    Madan Mohan Sati

    2015-01-01

    Full Text Available We propose a generalized cumulative residual information measure based on Tsallis entropy and its dynamic version. We study the characterizations of the proposed information measure and define new classes of life distributions based on this measure. Some applications are provided in relation to weighted and equilibrium probability models. Finally the empirical cumulative Tsallis entropy is proposed to estimate the new information measure.

  18. Cumulative query method for influenza surveillance using search engine data.

    Science.gov (United States)

    Seo, Dong-Woo; Jo, Min-Woo; Sohn, Chang Hwan; Shin, Soo-Yong; Lee, JaeHo; Yu, Maengsoo; Kim, Won Young; Lim, Kyoung Soo; Lee, Sang-Il

    2014-12-16

    Internet search queries have become an important data source in syndromic surveillance system. However, there is currently no syndromic surveillance system using Internet search query data in South Korea. The objective of this study was to examine correlations between our cumulative query method and national influenza surveillance data. Our study was based on the local search engine, Daum (approximately 25% market share), and influenza-like illness (ILI) data from the Korea Centers for Disease Control and Prevention. A quota sampling survey was conducted with 200 participants to obtain popular queries. We divided the study period into two sets: Set 1 (the 2009/10 epidemiological year for development set 1 and 2010/11 for validation set 1) and Set 2 (2010/11 for development Set 2 and 2011/12 for validation Set 2). Pearson's correlation coefficients were calculated between the Daum data and the ILI data for the development set. We selected the combined queries for which the correlation coefficients were .7 or higher and listed them in descending order. Then, we created a cumulative query method n representing the number of cumulative combined queries in descending order of the correlation coefficient. In validation set 1, 13 cumulative query methods were applied, and 8 had higher correlation coefficients (min=.916, max=.943) than that of the highest single combined query. Further, 11 of 13 cumulative query methods had an r value of ≥.7, but 4 of 13 combined queries had an r value of ≥.7. In validation set 2, 8 of 15 cumulative query methods showed higher correlation coefficients (min=.975, max=.987) than that of the highest single combined query. All 15 cumulative query methods had an r value of ≥.7, but 6 of 15 combined queries had an r value of ≥.7. Cumulative query method showed relatively higher correlation with national influenza surveillance data than combined queries in the development and validation set.

  19. Steps and pips in the history of the cumulative recorder.

    OpenAIRE

    Lattal, Kennon A

    2004-01-01

    From its inception in the 1930s until very recent times, the cumulative recorder was the most widely used measurement instrument in the experimental analysis of behavior. It was an essential instrument in the discovery and analysis of schedules of reinforcement, providing the first real-time analysis of operant response rates and patterns. This review traces the evolution of the cumulative recorder from Skinner's early modified kymographs through various models developed by Skinner and his co...

  20. High frequency somatosensory stimulation increases sensori-motor inhibition and leads to perceptual improvement in healthy subjects.

    Science.gov (United States)

    Rocchi, Lorenzo; Erro, Roberto; Antelmi, Elena; Berardelli, Alfredo; Tinazzi, Michele; Liguori, Rocco; Bhatia, Kailash; Rothwell, John

    2017-06-01

    High frequency repetitive somatosensory stimulation (HF-RSS), which is a patterned electric stimulation applied to the skin through surface electrodes, improves two-point discrimination, somatosensory temporal discrimination threshold (STDT) and motor performance in humans. However, the mechanisms which underlie these changes are still unknown. In particular, we hypothesize that refinement of inhibition might be responsible for the improvement in spatial and temporal perception. Fifteen healthy subjects underwent 45min of HF-RSS. Before and after the intervention several measures of inhibition in the primary somatosensory area (S1), such as paired-pulse somatosensory evoked potentials (pp-SEP), high-frequency oscillations (HFO), and STDT were tested, as well as tactile spatial acuity and short intracortical inhibition (SICI). HF-RSS increased inhibition in S1 tested by pp-SEP and HFO; these changes were correlated with improvement in STDT. HF-RSS also enhanced bumps detection, while there was no change in grating orientation test. Finally there was an increase in SICI, suggesting widespread changes in cortical sensorimotor interactions. These findings suggest that HF-RSS can improve spatial and temporal tactile abilities by increasing the effectiveness of inhibitory interactions in the somatosensory system. Moreover, HF-RSS induces changes in cortical sensorimotor interaction. HF-RSS is a repetitive electric stimulation technique able to modify the effectiveness of inhibitory circuitry in the somatosensory system and primary motor cortex. Copyright © 2017 International Federation of Clinical Neurophysiology. All rights reserved.

  1. Phantom acupuncture: dissociating somatosensory and cognitive/affective components of acupuncture stimulation with a novel form of placebo acupuncture.

    Directory of Open Access Journals (Sweden)

    Jeungchan Lee

    Full Text Available In a clinical setting, acupuncture treatment consists of multiple components including somatosensory stimulation, treatment context, and attention to needle-based procedures. In order to dissociate somatosensory versus contextual and attentional aspects of acupuncture, we devised a novel form of placebo acupuncture, a visual manipulation dubbed phantom acupuncture, which reproduces the acupuncture needling ritual without somatosensory tactile stimulation. Subjects (N = 20 received both real (REAL and phantom (PHNT acupuncture. Subjects were retrospectively classified into two groups based on PHNT credibility (PHNTc, who found phantom acupuncture credible; and PHNTnc, who did not. Autonomic and psychophysical responses were monitored. We found that PHNT can be delivered in a credible manner. Acupuncture needling, a complex, ritualistic somatosensory intervention, induces sympathetic activation (phasic skin conductance [SC] response, which may be specific to the somatosensory component of acupuncture. In contrast, contextual effects, such as needling credibility, are instead associated with a shift toward relative cardiovagal activation (decreased heart rate during needling and sympathetic inhibition (decreased SC and parasympathetic activation (decreased pupil size following acupuncture needling. Visual stimulation characterizing the needling ritual is an important factor for phasic autonomic responses to acupuncture and may undelie the needling orienting response. Our study suggests that phantom acupuncture can be a viable sham control for acupuncture as it completely excludes the somatosensory component of real needling while maintaining the credibility of the acupuncture treatment context in many subjects.

  2. Childhood Cumulative Risk Exposure and Adult Amygdala Volume and Function.

    Science.gov (United States)

    Evans, Gary W; Swain, James E; King, Anthony P; Wang, Xin; Javanbakht, Arash; Ho, S Shaun; Angstadt, Michael; Phan, K Luan; Xie, Hong; Liberzon, Israel

    2016-06-01

    Considerable work indicates that early cumulative risk exposure is aversive to human development, but very little research has examined the neurological underpinnings of these robust findings. This study investigates amygdala volume and reactivity to facial stimuli among adults (mean 23.7 years of age, n = 54) as a function of cumulative risk exposure during childhood (9 and 13 years of age). In addition, we test to determine whether expected cumulative risk elevations in amygdala volume would mediate functional reactivity of the amygdala during socioemotional processing. Risks included substandard housing quality, noise, crowding, family turmoil, child separation from family, and violence. Total and left hemisphere adult amygdala volumes were positively related to cumulative risk exposure during childhood. The links between childhood cumulative risk exposure and elevated amygdala responses to emotionally neutral facial stimuli in adulthood were mediated by the corresponding amygdala volumes. Cumulative risk exposure in later adolescence (17 years of age), however, was unrelated to subsequent adult amygdala volume or function. Physical and socioemotional risk exposures early in life appear to alter amygdala development, rendering adults more reactive to ambiguous stimuli such as neutral faces. These stress-related differences in childhood amygdala development might contribute to the well-documented psychological distress as a function of early risk exposure. © 2015 Wiley Periodicals, Inc.

  3. Assessment of somatosensory indicators of polyneuropathy in patients with eating disorders.

    Science.gov (United States)

    Pauls, A M; Lautenbacher, S; Strian, F; Pirke, K M; Krieg, J C

    1991-01-01

    The somatosensory functions of small-diameter nerve fibres were tested on the lower and upper extremities in nine patients with anorexia nervosa, ten patients with bulimia nervosa and ten control subjects, by analysing warmth, cold, and pain thresholds. To test large-diameter nerve fibres, the vibration threshold was also measured. Both patient groups had markedly elevated pain thresholds compared with the control subjects. In contrast, warmth and cold thresholds were only suggestively elevated while vibration thresholds were not at all increased in the patients. A distal-proximal pattern of somatosensory deficits, suggestive of peripheral polyneuropathy, was not observed. Hence, a peripheral polyneuropathy affecting small or large afferent fibres as a consequence of an eating disorder seems to be a rare event.

  4. Somatosensory evoked potentials (S.E.P.) in slow pathological compression of the spinal cord.

    Science.gov (United States)

    Rossini, P M; Greco, F; David, P; Pisano, L; De Palma, L; Tonali, P

    1979-12-01

    Somatosensory evoked potentials (S.E.P.) were used to examine twelve patients who had slow compressive lesions of the spinal cord (ten cases of spondylotic myelopathy, one neurinoma, one metastasis of a vertebral body). 73 per cent of the recordings were found to be abnormally reduced in amplitude, and/or showed prolonged latency times aa regards the primary and secondary complex. Patients with a clinical lesion of the dorsal column showed a clear reduction in amplitude in the recordings (sometimes coupled with slowed latency), especially in the primary complex. Patients with symptoms indicative of an injury to the ventrolateral region of the spinal cord showed tracings with alterations most of all related to the secondary complex. In 76 per cent of cases, the somatosensory evoked potentials were in accordance with the level of the compression, the degree of invalidity, and the clinical picture.

  5. [Multi-sensory interaction in tinnitus: visual evoked potentials and somatosensory stimulation].

    Science.gov (United States)

    Herráiz, C; Hernández-Calvín, F J; Plaza, G; Toledano, A; De los Santos, G

    2003-05-01

    Anomalous cross-modal interactions along the audiovestibular, visual and soma-tosensorial pathways could be the responsible for aberrant signals, clinically expressed as phantom perceptions. This results in tinnitus that can be modified by gaze movements or somatosensorial stimulation through skin, orofacial (jaw) and cervical movements. This phenomenon has also been described in some patients with acute unilateral deafferentation of the auditory peripheral system as a result of surgery to remove a tumour in the posterior fossal. Neuroimaging preliminary studies (PET, f-MRI) describe multisensorial interactions and cortical reorganisation processes in chronic tinnitus. Treatment approaches are still unknown although counselling regarding the benignity of the process and the high percentage of habituation to the symptom is the most effective framework. We present our experience in four cases.

  6. A functional MRI study of somatotopic representation of somatosensory stimulation in the cerebellum

    Energy Technology Data Exchange (ETDEWEB)

    Takanashi, M.; Abe, K.; Yanagihara, T.; Sakoda, S. [Dept. of Neurology D4, Osaka Univ. Graduate School of Medicine, Suita City, Osaka (Japan); Tanaka, H.; Hirabuki, N.; Nakamura, H.; Fujita, N. [Dept. of Radiology, Osaka Univ. Graduate School of Medicine, Suita City, Osaka (Japan)

    2003-03-01

    Somatotopic representation in the cerebral cortex of somatosensory stimulation has been widely reported, but that in the cerebellum has not. We investigated the latter in the human cerebellum by functional MRI (fMRI). Using a 1.5 tesla imager, we obtained multislice blood oxygen level-dependent fMRI with single-shot gradient-echo echoplanar imaging in seven right-handed volunteers during electrical stimulation of the left index finger and big toe. In the anterior and posterior cerebellum, activated pixels for the index finger were separate from those for the toe. This suggests that somatosensory stimulation of different parts of the body may involve distinct areas of in the cerebellum as well as the cerebral cortex. (orig.)

  7. Perceptual learning with tactile stimuli in rodents: Shaping the somatosensory system.

    Science.gov (United States)

    Pacchiarini, Nicole; Fox, Kevin; Honey, R C

    2017-06-01

    The animal kingdom contains species with a wide variety of sensory systems that have been selected to function in different environmental niches, but that are also subject to modification by experience during an organism's lifetime. The modification of such systems by experience is often called perceptual learning. In rodents, the classic example of perceptual learning is the observation that simple preexposure to two visual stimuli facilitates a subsequent (reinforced) discrimination between them. However, until recently very little behavioral research had investigated perceptual learning with tactile stimuli in rodents, in marked contrast to the wealth of information about plasticity in the rodent somatosensory system. Here we present a selective review of behavioral analyses of perceptual learning with tactile stimuli, alongside evidence concerning the potential bases of such effects within the somatosensory system.

  8. Sense, memory, and decision-making in the somatosensory cortical network.

    Science.gov (United States)

    Romo, Ranulfo; Lemus, Luis; de Lafuente, Victor

    2012-12-01

    The brain constructs representations of objects and concepts based in sensory information combined with experience. This mental process, that we call perception, is the result of a chain of events consisting of phenomena such as detection, memory, discrimination, categorization and decision-making. Although the phenomenon of perception is not necessarily dependent on a given sensory modality (e.g. visual perception, auditory, tactile), single sensory models are indispensable for studying the neural mechanisms that generate it. The somatosensory system is a suitable model for studying the manner in which presentation of a single physical variable (e.g. vibration) triggers a perceptual process. Here, we discuss some recent studies in the somatosensory system that in our view, constitute a breakthrough to understanding decision making. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Modality-Based Organization of Ascending Somatosensory Axons in the Direct Dorsal Column Pathway

    Science.gov (United States)

    Niu, Jingwen; Ding, Long; Li, Jian J.; Kim, Hyukmin; Liu, Jiakun; Li, Haipeng; Moberly, Andrew; Badea, Tudor C.; Duncan, Ian D.; Son, Young-Jin; Scherer, Steven S.

    2013-01-01

    The long-standing doctrine regarding the functional organization of the direct dorsal column (DDC) pathway is the “somatotopic map” model, which suggests that somatosensory afferents are primarily organized by receptive field instead of modality. Using modality-specific genetic tracing, here we show that ascending mechanosensory and proprioceptive axons, two main types of the DDC afferents, are largely segregated into a medial–lateral pattern in the mouse dorsal column and medulla. In addition, we found that this modality-based organization is likely to be conserved in other mammalian species, including human. Furthermore, we identified key morphological differences between these two types of afferents, which explains how modality segregation is formed and why a rough “somatotopic map” was previously detected. Collectively, our results establish a new functional organization model for the mammalian direct dorsal column pathway and provide insight into how somatotopic and modality-based organization coexist in the central somatosensory pathway. PMID:24198362

  10. Reorganization of the somatosensory cortex in hemiplegic cerebral palsy associated with impaired sensory tracts

    Directory of Open Access Journals (Sweden)

    Christos Papadelis

    2018-01-01

    Full Text Available Functional neuroimaging studies argue that sensory deficits in hemiplegic cerebral palsy (HCP are related to deviant somatosensory processing in the ipsilesional primary somatosensory cortex (S1. A separate body of structural neuroimaging literature argues that these deficits are due to structural damage of the ascending sensory tracts (AST. The relationship between the functional and structural integrity of the somatosensory system and the sensory performance is largely unknown in HCP. To address this relationship, we combined findings from magnetoencephalography (MEG and probabilistic diffusion tractography (PDT in 10 children with HCP and 13 typically developing (TD children. With MEG, we mapped the functionally active regions in the contralateral S1 during tactile stimulation of the thumb, middle, and little fingers of both hands. Using these MEG-defined functional active regions as regions of interest for PDT, we estimated the diffusion parameters of the AST. Somatosensory function was assessed via two-point discrimination tests. Our MEG data showed: (i an abnormal somatotopic organization in all children with HCP in either one or both of their hemispheres; (ii longer Euclidean distances between the digit maps in the S1 of children with HCP compared to TD children; (iii suppressed gamma responses at early latencies for both hemispheres of children with HCP; and (iv a positive correlation between the Euclidean distances and the sensory tests for the more affected hemisphere of children with HCP. Our MEG-guided PDT data showed: (i higher mean and radian diffusivity of the AST in children with HCP; (ii a positive correlation between the axial diffusivity of the AST with the sensory tests for the more affected hemisphere; and (iii a negative correlation between the gamma power change and the AD of the AST for the MA hemisphere. Our findings associate for the first time bilateral cortical functional reorganization in the S1 of HCP children with

  11. [Exploration of the optic and somatosensory pathways with cerebral evoked potentials].

    Science.gov (United States)

    Ghezzi, A; Zibetti, A

    1981-06-16

    Visual and somatosensorial evoked potentials are the electrical response, recorded on the scalp, that follows the presentation of visual and sensorial stimuli. After briefly mentioning the technical premises enabling evoked responses to be obtained from EEC activity, some cases are reported (demyelining, degenerative, compressive, ischaemic, anoxic pathology) where visual or sensory evoked potentials presented changes, proof of the usefulness of these techniques for the purposes of clinical documentation or for diagnosis in different fields of DNS pathology.

  12. Cross-sectional imaging of functional activation in the rat somatosensory cortex with optical coherence tomography

    Science.gov (United States)

    Aguirre, A. D.; Chen, Y.; Ruvinskaya, L.; Devor, A.; Boas, D. A.; Fujimoto, J. G.

    2005-08-01

    Simultaneous optical coherence tomography (OCT) and video microscopy were performed on the rat somatosensory cortex through a thinned skull during forepaw stimulation. Fractional change measurements in OCT images reveal a functional signal timecourse similar to well understood hemodynamic signal timecourses measured with video microscopy. The precise etiology of the observed OCT functional signal is still under investigation, but these results suggest that OCT can provide high-resolution cross-sectional images of functional neuro-vascular activation.

  13. Reorganization of the somatosensory cortex in hemiplegic cerebral palsy associated with impaired sensory tracts.

    Science.gov (United States)

    Papadelis, Christos; Butler, Erin E; Rubenstein, Madelyn; Sun, Limin; Zollei, Lilla; Nimec, Donna; Snyder, Brian; Grant, Patricia Ellen

    2018-01-01

    Functional neuroimaging studies argue that sensory deficits in hemiplegic cerebral palsy (HCP) are related to deviant somatosensory processing in the ipsilesional primary somatosensory cortex (S1). A separate body of structural neuroimaging literature argues that these deficits are due to structural damage of the ascending sensory tracts (AST). The relationship between the functional and structural integrity of the somatosensory system and the sensory performance is largely unknown in HCP. To address this relationship, we combined findings from magnetoencephalography (MEG) and probabilistic diffusion tractography (PDT) in 10 children with HCP and 13 typically developing (TD) children. With MEG, we mapped the functionally active regions in the contralateral S1 during tactile stimulation of the thumb, middle, and little fingers of both hands. Using these MEG-defined functional active regions as regions of interest for PDT, we estimated the diffusion parameters of the AST. Somatosensory function was assessed via two-point discrimination tests. Our MEG data showed: (i) an abnormal somatotopic organization in all children with HCP in either one or both of their hemispheres; (ii) longer Euclidean distances between the digit maps in the S1 of children with HCP compared to TD children; (iii) suppressed gamma responses at early latencies for both hemispheres of children with HCP; and (iv) a positive correlation between the Euclidean distances and the sensory tests for the more affected hemisphere of children with HCP. Our MEG-guided PDT data showed: (i) higher mean and radian diffusivity of the AST in children with HCP; (ii) a positive correlation between the axial diffusivity of the AST with the sensory tests for the more affected hemisphere; and (iii) a negative correlation between the gamma power change and the AD of the AST for the MA hemisphere. Our findings associate for the first time bilateral cortical functional reorganization in the S1 of HCP children with

  14. Premotor cortex modulates somatosensory cortex during voluntary movements without proprioceptive feedback

    DEFF Research Database (Denmark)

    Christensen, Mark Schram; Lundbye-Jensen, Jesper; Geertsen, Svend Sparre

    2007-01-01

    Movement perception relies on sensory feedback, but the involvement of efference copies remains unclear. We investigated movements without proprioceptive feedback using ischemic nerve block during fMRI in healthy humans, and found preserved activation of the primary somatosensory cortex....... This activation was associated with increased interaction with premotor cortex during voluntary movements, which demonstrates that perception of movements relies in part on predictions of sensory consequences of voluntary movements that are mediated by the premotor cortex....

  15. Vestibular-Somatosensory Convergence in Head Movement Control During Locomotion after Long-Duration Space Flight

    Science.gov (United States)

    Mulavara, Ajitkumar; Ruttley, Tara; Cohen, Helen; Peters, Brian; Miller, Chris; Brady, Rachel; Merkle, Lauren; Bloomberg, Jacob

    2010-01-01

    Exposure to the microgravity conditions of space flight induces adaptive modification in the control of vestibular-mediated reflexive head movement during locomotion after space flight. Space flight causes astronauts to be exposed to somatosensory adaptation in both the vestibular and body load-sensing (BLS) systems. The goal of these studies was to examine the contributions of vestibular and BLS-mediated somatosensory influences on head movement control during locomotion after long-duration space flight. Subjects were asked to walk on a treadmill driven at 1.8 m/s while performing a visual acuity task. Data were collected using the same testing protocol from three independent subject groups; 1) normal subjects before and after exposure to 30 minutes of 40% bodyweight unloaded treadmill walking, 2) bilateral labyrinthine deficient (LD) patients and 3) astronauts who performed the protocol before and after long duration space flight. Motion data from head and trunk segmental motion data were obtained to calculate the angular head pitch (HP) movements during walking trials while subjects performed the visual task, to estimate the contributions of vestibular reflexive mechanisms in HP movements. Results showed that exposure to unloaded locomotion caused a significant increase in HP movements, whereas in the LD patients the HP movements were significantly decreased. Astronaut subjects results showed a heterogeneous response of both increases and decreases in the amplitude of HP movement. We infer that BLS-mediated somatosensory input centrally modulates vestibular input and can adaptively modify head-movement control during locomotion. Thus, space flight may cause a central adaptation mediated by the converging vestibular and body load-sensing somatosensory systems.

  16. Children with cerebral palsy have uncharacteristic somatosensory cortical oscillations after stimulation of the hand mechanoreceptors.

    Science.gov (United States)

    Kurz, M J; Becker, K M; Heinrichs-Graham, E; Wilson, T W

    2015-10-01

    Numerous clinical investigations have reported that children with cerebral palsy (CP) have tactile discrimination deficits that likely limit their ability to plan and manipulate objects. Despite this clinical awareness, we still have a substantial knowledge gap in our understanding of the neurological basis for these tactile discrimination deficits. Previously, we have shown that children with CP have aberrant theta-alpha (4-14 Hz) oscillations in the somatosensory cortices following tactile stimulation of the foot. In this investigation, we evaluated if these aberrant theta-alpha oscillations also extend to the hand. Magnetoencephalography was used to evaluate event-related changes in the theta-alpha and beta (18-34 Hz) somatosensory cortical oscillations in groups of children with CP and typically developing (TD) children following tactile stimulation of their hands. Our results showed that the somatosensory theta-alpha oscillations were relatively intact in children with CP, which is in contrast to our previous results for foot tactile stimulations. We suspect that these inter-study differences may be related to the higher probability that the neural tracts serving the lower extremities are damaged in children with CP, compared to those serving the upper extremities. This inference is plausible since the participating children with CP had Manual Ability Classification System (MACS) levels between I and II. In contrast to the theta-alpha results, children with CP did exhibit a sharp increase in beta activity during the same time period, which was not observed in TD children. This suggests that children with CP still have deficits in the computational aspect of somatosensory processing. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  17. Activity and topographic changes in the somatosensory system in embouchure dystonia.

    Science.gov (United States)

    Mantel, Tobias; Dresel, Christian; Altenmüller, Eckart; Zimmer, Claus; Noe, Jonas; Haslinger, Bernhard

    2016-11-01

    Embouchure dystonia is a highly disabling focal task-specific dystonia affecting professional brass players. This study was designed to analyze activity changes along with topographic representations in primary and nonprimary centers for somatosensory processing in patients with embouchure dystonia. We used event-related functional magnetic resonance imaging with automized tactile stimulation of dystonic (upper lip) and nondystonic (forehead and dorsal hand) body regions in 15 professional brass players with and without embouchure dystonia. Statistical analyses included whole-brain between-group comparisons of stimulation-induced activation and region-of-interest-based single patient analyses of topographic activation characteristics. Affected musicians revealed increased stimulation-induced activity in contralateral primary and bilateral secondary somatosensory representations of dystonic and nondystonic body regions as well as in the cerebellum ipsilateral to the left dystonic upper lip. Changes of somatotopic organization with altered intracortical distances and between-group differences of the centers of representations were found in the right primary and the bilateral secondary somatosensory cortex and in the left cerebellum. Positional variability of dystonic and nondystonic body regions was reduced with an emphasis on face representations. The present findings are supportive of the concept of an abnormal processing of somatosensory information in embouchure dystonia affecting multiple domains. The underlying neurophysiological mechanisms (eg, changes in inhibition, maladaptive plasticity, changes in baseline activity) remain unclear. The involvement of nondystonic body areas can be viewed in the context of possible compensation or an endophenotypic predisposition. © 2016 International Parkinson and Movement Disorder Society. © 2016 International Parkinson and Movement Disorder Society.

  18. Distributed functions of detection and discrimination of vibrotactile stimuli in the hierarchical human somatosensory system.

    Science.gov (United States)

    Kim, Junsuk; Müller, Klaus-Robert; Chung, Yoon Gi; Chung, Soon-Cheol; Park, Jang-Yeon; Bülthoff, Heinrich H; Kim, Sung-Phil

    2014-01-01

    According to the hierarchical view of human somatosensory network, somatic sensory information is relayed from the thalamus to primary somatosensory cortex (S1), and then distributed to adjacent cortical regions to perform further perceptual and cognitive functions. Although a number of neuroimaging studies have examined neuronal activity correlated with tactile stimuli, comparatively less attention has been devoted toward understanding how vibrotactile stimulus information is processed in the hierarchical somatosensory cortical network. To explore the hierarchical perspective of tactile information processing, we studied two cases: (a) discrimination between the locations of finger stimulation; and (b) detection of stimulation against no stimulation on individual fingers, using both standard general linear model (GLM) and searchlight multi-voxel pattern analysis (MVPA) techniques. These two cases were studied on the same data set resulting from a passive vibrotactile stimulation experiment. Our results showed that vibrotactile stimulus locations on fingers could be discriminated from measurements of human functional magnetic resonance imaging (fMRI). In particular, it was in case (a) we observed activity in contralateral posterior parietal cortex (PPC) and supramarginal gyrus (SMG) but not in S1, while in case; (b) we found significant cortical activations in S1 but not in PPC and SMG. These discrepant observations suggest the functional specialization with regard to vibrotactile stimulus locations, especially, the hierarchical information processing in the human somatosensory cortical areas. Our findings moreover support the general understanding that S1 is the main sensory receptive area for the sense of touch, and adjacent cortical regions (i.e., PPC and SMG) are in charge of a higher level of processing and may thus contribute most for the successful classification between stimulated finger locations.

  19. Inhibition of somatosensory-evoked cortical responses by a weak leading stimulus.

    Science.gov (United States)

    Nakagawa, Kei; Inui, Koji; Yuge, Louis; Kakigi, Ryusuke

    2014-11-01

    We previously demonstrated that auditory-evoked cortical responses were suppressed by a weak leading stimulus in a manner similar to the prepulse inhibition (PPI) of startle reflexes. The purpose of the present study was to investigate whether a similar phenomenon was present in the somatosensory system, and also whether this suppression reflected an inhibitory process. We recorded somatosensory-evoked magnetic fields following stimulation of the median nerve and evaluated the extent by which they were suppressed by inserting leading stimuli at an intensity of 2.5-, 1.5-, 1.1-, or 0.9-fold the sensory threshold (ST) in healthy participants (Experiment 1). The results obtained demonstrated that activity in the secondary somatosensory cortex in the hemisphere contralateral to the stimulated side (cSII) was significantly suppressed by a weak leading stimulus with the intensity larger than 1.1-fold ST. This result implied that the somatosensory system had an inhibitory process similar to that of PPI. We then presented two successive leading stimuli before the test stimulus, and compared the extent of suppression between the test stimulus-evoked responses and those obtained with the second prepulse alone and with two prepulses (first and second) (Experiment 2). When two prepulses were preceded, cSII responses to the second prepulse were suppressed by the first prepulse, whereas the ability of the second prepulse to suppress the test stimulus remained unchanged. These results suggested the presence of at least two individual pathways; response-generating and inhibitory pathways. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Effects of visual information regarding tactile stimulation on the somatosensory cortical activation: a functional MRI study.

    Science.gov (United States)

    Kwon, Hyeok Gyu; Jang, Sung Ho; Lee, Mi Young

    2017-07-01

    Many studies have investigated the evidence for tactile and visual interactive responses to activation of various brain regions. However, few studies have reported on the effects of visuo-tactile multisensory integration on the amount of brain activation on the somatosensory cortical regions. The aim of this study was to examine whether coincidental information obtained by tactile stimulation can affect the somatosensory cortical activation using functional MRI. Ten right-handed healthy subjects were recruited for this study. Two tasks (tactile stimulation and visuotactile stimulation) were performed using a block paradigm during fMRI scanning. In the tactile stimulation task, in subjects with eyes closed, tactile stimulation was applied on the dorsum of the right hand, corresponding to the proximal to distal directions, using a rubber brush. In the visuotactile stimulation task, tactile stimulation was applied to observe the attached mirror in the MRI chamber reflecting their hands being touched with the brush. In the result of SPM group analysis, we found brain activation on the somatosensory cortical area. Tactile stimulation task induced brain activations in the left primary sensory-motor cortex (SM1) and secondary somatosensory cortex (S2). In the visuo-tactile stimulation task, brain activations were observed in the both SM1, both S2, and right posterior parietal cortex. In all tasks, the peak activation was detected in the contralateral SM1. We examined the effects of visuo-tactile multisensory integration on the SM1 and found that visual information during tactile stimulation could enhance activations on SM1 compared to the tactile unisensory stimulation.

  1. Effects of prenatal nicotine exposure on the morphogenesis of somatosensory cortex.

    Science.gov (United States)

    Roy, T S; Sabherwal, U

    1994-01-01

    Human reports as well as animal studies have recorded accelerated motor activity, learning, and memory deficits in offsprings of mothers exposed to nicotine during pregnancy. Morphological correlation of these neurobehavioural defects has not been done to date. Here, the cerebral cortex has been evaluated after prenatal nicotine exposure. Groups of pregnant rats were injected IP with nicotine at 2.5 mg/kg/day dosage from gestational day (GD) 6 to term. Morphology of the somatosensory cortex was analysed and compared with that of the control group up to postnatal day (PND) 40. A significant reduction in body weight and brain weight on PND 10 and 20, respectively was observed in nicotine exposed group as compared to age matched controls. Morphometric analysis of the somatosensory cortex showed a reduction in cortical thickness up to PND 20 and decreased cell size at PND 10, 20, and 40 in nicotine-exposed brains. Neuronal density of Layer 5 of somatosensory cortex was greater at PND 20 and 40 in the experimental group. Golgi staining of large pyramidal neurons of Layer 5 showed significantly decreased dendritic branching and increased dendritic spine density in the experimental group at all ages studied. Irregular arrangement of cisternae of rough endoplasmic reticulum, paucity of free ribosomes, and frequent cytoplasmic vacuoles were noted by electron microscopy in many neurons up to PND 40. A large number of electron dense cells were observed in nicotine exposed brains at all the time intervals studied. The morphological features of somatosensory cortex observed after prenatal nicotine administration suggest that the drug delays neuronal maturation and affects intracytoplasmic membrane systems.

  2. Effect of extradural morphine on somatosensory evoked potentials to dermatomal stimulation

    DEFF Research Database (Denmark)

    Lund, C; Selmar, P; Hansen, O B

    1987-01-01

    The effect of the extradural (L2-3) administration of morphine 6 mg on early (less than 0.5 s) somatosensory evoked cortical potentials (SEP) to electrical stimulation of the L1- and S1-dermatomes was examined in eight patients. Extradural morphine did not influence SEP amplitude. SEP latency did...... not change, except for a minor increase in the latencies of the onset and the P2 components following S1 stimulation....

  3. Decreased Somatosensory Activity to Non-threatening Touch in Combat Veterans with Posttraumatic Stress Disorder

    OpenAIRE

    Badura-Brack, Amy S.; Becker, Katherine M.; McDermott, Timothy J.; Ryan, Tara J.; Becker, Madelyn M.; Hearley, Allison R.; Heinrichs-Graham, Elizabeth; Wilson, Tony W.

    2015-01-01

    Posttraumatic stress disorder (PTSD) is a severe psychiatric disorder prevalent in combat veterans. Previous neuroimaging studies have demonstrated that patients with PTSD exhibit abnormal responses to non-threatening visual and auditory stimuli, but have not examined somatosensory processing. Thirty male combat veterans, 16 with PTSD and 14 without, completed a tactile stimulation task during a 306-sensor magnetoencephalography (MEG) recording. Significant oscillatory neural responses were i...

  4. Distributed functions of detection and discrimination of vibrotactile stimuli in the hierarchical human somatosensory system

    Directory of Open Access Journals (Sweden)

    Junsuk eKim

    2015-01-01

    Full Text Available According to the hierarchical view of human somatosensory network, somatic sensory information is relayed from the thalamus to primary somatosensory cortex (S1, and then distributed to adjacent cortical regions to perform further perceptual and cognitive functions. Although a number of neuroimaging studies have examined neuronal activity correlated with tactile stimuli, comparatively less attention has been devoted toward understanding how vibrotactile stimulus information is processed in the hierarchical somatosensory cortical network. To explore the hierarchical perspective of tactile information processing, we studied two cases: (a discrimination between the locations of finger stimulation, and (b detection of stimulation against no stimulation on individual fingers, using both standard general linear model (GLM and searchlight multi-voxel pattern analysis (MVPA techniques. These two cases were studied on the same data set resulting from a passive vibrotactile stimulation experiment. Our results showed that vibrotactile stimulus locations on fingers could be discriminated from measurements of human functional magnetic resonance imaging (fMRI. In particular, it was in case (a where we observed activity in contralateral posterior parietal cortex (PPC and supramarginal gyrus (SMG but not in S1, while in case (b we found significant cortical activations in S1 but not in PPC and SMG. These discrepant observations suggest the functional specialization with regard to vibrotactile stimulus locations, especially, the hierarchical information processing in the human somatosensory cortical areas. Our findings moreover support the general understanding that S1 is the main sensory receptive area for the sense of touch, and adjacent cortical regions (i.e., PPC and SMG are in charge of a higher level of processing and may thus contribute most for the successful classification between stimulated finger locations.

  5. Effects of visual information regarding tactile stimulation on the somatosensory cortical activation: a functional MRI study

    Directory of Open Access Journals (Sweden)

    Hyeok Gyu Kwon

    2017-01-01

    Full Text Available Many studies have investigated the evidence for tactile and visual interactive responses to activation of various brain regions. However, few studies have reported on the effects of visuo-tactile multisensory integration on the amount of brain activation on the somatosensory cortical regions. The aim of this study was to examine whether coincidental information obtained by tactile stimulation can affect the somatosensory cortical activation using functional MRI. Ten right-handed healthy subjects were recruited for this study. Two tasks (tactile stimulation and visuotactile stimulation were performed using a block paradigm during fMRI scanning. In the tactile stimulation task, in subjects with eyes closed, tactile stimulation was applied on the dorsum of the right hand, corresponding to the proximal to distal directions, using a rubber brush. In the visuotactile stimulation task, tactile stimulation was applied to observe the attached mirror in the MRI chamber reflecting their hands being touched with the brush. In the result of SPM group analysis, we found brain activation on the somatosensory cortical area. Tactile stimulation task induced brain activations in the left primary sensory-motor cortex (SM1 and secondary somatosensory cortex (S2. In the visuo-tactile stimulation task, brain activations were observed in the both SM1, both S2, and right posterior parietal cortex. In all tasks, the peak activation was detected in the contralateral SM1. We examined the effects of visuo-tactile multisensory integration on the SM1 and found that visual information during tactile stimulation could enhance activations on SM1 compared to the tactile unisensory stimulation.

  6. The Amphiolite Layers In The Cumulate Gabbros, (Northern-Turkey)

    Science.gov (United States)

    Özkan, Mutlu; Faruk Çelik, Ömer; Altıntaş, İsmail Emir; Sherlock, Sarah; Chelle-Michou, Cyril; Marzoli, Andrea; Ulianov, Alexey; Melih Çörtük, Rahmi; Topuz, Gültekin

    2016-04-01

    The Early-Middle Jurassic SSZ type dismembered ophiolite sequence, which is remnants of the Tethyan oceanic lithosphere, crop out in the accretionary complex around Tokat-Çamlıbel region (Northern Turkey). The main lithology of the ophiolite sequence are cumulate gabbros, isotropic gabbros and basalts. The amphibolite layers, which their thickness are up to 2 m, are observed in the cumulate gabbros. In this study, we aim to discuss a possible formation mechanism of the amphibolitic rocks in the cumulate gabbros, based on the field, mineralogical, geochemical and geochronological data. The cumulate gabbros (olivine-gabbro, gabbro-norite and gabbro) have generally well developed magmatic layers and they show cumulate texture. They are cross cut by pegmatite gabbros, dolerites and plagiogranite dikes. In terms of the mechanism of formation, the amphibolite layers in the cumulate gabbros are different from dolerite, pegmatite gabbro and plagiogranite dikes crosscutting the cumulate gabbros. Although the cumulate gabbros, the mafic and felsic dikes have not undergone any metamorphism (except the hydrothermal metamorphism), the amphibolite layers show well developed foliation and banded structure. Moreover, field and petrographic observations showed that the amphibolitic rocks were highly subjected to shearing. The amphibolitic rocks are mainly composed of magnesio-hornblende + plagioclase (andesine), ± biotite and opaque minerals and they exhibit nematoblastic texture. The amphibolite layers in the cumulate gabbros are crosscut by the plagiogranite dikes. The plagiogranites consist mainly of quartz, plagioclase, biotite and opaque minerals and they show granular texture. Undulose extinction and sub-grain formation in quartz minerals indicate to the presence of deformation phase affecting the plagiogranite dikes. LA-ICP-MS dating on zircon from plagiogranite dikes which is cross-cutting of the amphibolite layers, yielded Middle Jurassic ages. 40Ar/39Ar dating of

  7. Auditory-somatosensory bimodal stimulation desynchronizes brain circuitry to reduce tinnitus in guinea pigs and humans.

    Science.gov (United States)

    Marks, Kendra L; Martel, David T; Wu, Calvin; Basura, Gregory J; Roberts, Larry E; Schvartz-Leyzac, Kara C; Shore, Susan E

    2018-01-03

    The dorsal cochlear nucleus is the first site of multisensory convergence in mammalian auditory pathways. Principal output neurons, the fusiform cells, integrate auditory nerve inputs from the cochlea with somatosensory inputs from the head and neck. In previous work, we developed a guinea pig model of tinnitus induced by noise exposure and showed that the fusiform cells in these animals exhibited increased spontaneous activity and cross-unit synchrony, which are physiological correlates of tinnitus. We delivered repeated bimodal auditory-somatosensory stimulation to the dorsal cochlear nucleus of guinea pigs with tinnitus, choosing a stimulus interval known to induce long-term depression (LTD). Twenty minutes per day of LTD-inducing bimodal (but not unimodal) stimulation reduced physiological and behavioral evidence of tinnitus in the guinea pigs after 25 days. Next, we applied the same bimodal treatment to 20 human subjects with tinnitus using a double-blinded, sham-controlled, crossover study. Twenty-eight days of LTD-inducing bimodal stimulation reduced tinnitus loudness and intrusiveness. Unimodal auditory stimulation did not deliver either benefit. Bimodal auditory-somatosensory stimulation that induces LTD in the dorsal cochlear nucleus may hold promise for suppressing chronic tinnitus, which reduces quality of life for millions of tinnitus sufferers worldwide. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  8. Prefrontal cortex and somatosensory cortex in tactile crossmodal association: an independent component analysis of ERP recordings.

    Directory of Open Access Journals (Sweden)

    Yixuan Ku

    2007-08-01

    Full Text Available Our previous studies on scalp-recorded event-related potentials (ERPs showed that somatosensory N140 evoked by a tactile vibration in working memory tasks was enhanced when human subjects expected a coming visual stimulus that had been paired with the tactile stimulus. The results suggested that such enhancement represented the cortical activities involved in tactile-visual crossmodal association. In the present study, we further hypothesized that the enhancement represented the neural activities in somatosensory and frontal cortices in the crossmodal association. By applying independent component analysis (ICA to the ERP data, we found independent components (ICs located in the medial prefrontal cortex (around the anterior cingulate cortex, ACC and the primary somatosensory cortex (SI. The activity represented by the IC in SI cortex showed enhancement in expectation of the visual stimulus. Such differential activity thus suggested the participation of SI cortex in the task-related crossmodal association. Further, the coherence analysis and the Granger causality spectral analysis of the ICs showed that SI cortex appeared to cooperate with ACC in attention and perception of the tactile stimulus in crossmodal association. The results of our study support with new evidence an important idea in cortical neurophysiology: higher cognitive operations develop from the modality-specific sensory cortices (in the present study, SI cortex that are involved in sensation and perception of various stimuli.

  9. Persistent recruitment of somatosensory cortex during active maintenance of hand images in working memory.

    Science.gov (United States)

    Galvez-Pol, A; Calvo-Merino, B; Capilla, A; Forster, B

    2018-03-13

    Working memory (WM) supports temporary maintenance of task-relevant information. This process is associated with persistent activity in the sensory cortex processing the information (e.g., visual stimuli activate visual cortex). However, we argue here that more multifaceted stimuli moderate this sensory-locked activity and recruit distinctive cortices. Specifically, perception of bodies recruits somatosensory cortex (SCx) beyond early visual areas (suggesting embodiment processes). Here we explore persistent activation in processing areas beyond the sensory cortex initially relevant to the modality of the stimuli. Using visual and somatosensory evoked-potentials in a visual WM task, we isolated different levels of visual and somatosensory involvement during encoding of body and non-body-related images. Persistent activity increased in SCx only when maintaining body images in WM, whereas visual/posterior regions' activity increased significantly when maintaining non-body images. Our results bridge WM and embodiment frameworks, supporting a dynamic WM process where the nature of the information summons specific processing resources. Copyright © 2018 Elsevier Inc. All rights reserved.

  10. Sleep deprivation affects somatosensory cortex excitability as tested through median nerve stimulation.

    Science.gov (United States)

    Gorgoni, Maurizio; Ferlazzo, Fabio; Moroni, Fabio; D'Atri, Aurora; Donarelli, Stefania; Fanelli, Stefania; Gizzi Torriglia, Isabella; Lauri, Giulia; Ferrara, Michele; Marzano, Cristina; Rossini, Paolo Maria; Bramanti, Placido; De Gennaro, Luigi

    2014-01-01

    Changes of cortical excitability after sleep deprivation (SD) in humans have been investigated mostly in motor cortex, while there is little empirical evidence concerning somatosensory cortex, and its plastic changes across SD. To assess excitability of primary somatosensory cortex (S1) and EEG voltage topographical characteristics associated with somatosensory evoked potentials (SEPs) during SD. Across 41 h of SD, 16 healthy subjects participated in 4 experimental sessions (11.00 a.m. and 11.00 p.m. of the 1st and 2nd day) with: a) subjective sleepiness ratings; b) EEG recordings; c) SEPs recordings; d) behavioral vigilance responses. A clear enhancement of cortical excitability after SD was indexed by: (a) an amplitude increase of different SEPs component in S1; (b) higher voltage in occipital (around 35-43 ms) and fronto-central areas (around 47-62 ms). Circadian fluctuations did not affect cortical excitability. Voltage changes in S1 were strongly related with post-SD fluctuations of subjective and behavioral sleepiness. Sleep may have a role in keeping cortical excitability at optimal (namely below potentially dangerous) levels for the human brain, rebalancing progressive changes in cortical responsiveness to incoming inputs occurred during time spent awake. On the other hand, higher level of cortical responsiveness after sleep loss may be one of the mechanisms accounting for post-SD alterations in vigilance and behavior. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. No modulatory effects by transcranial static magnetic field stimulation of human motor and somatosensory cortex.

    Science.gov (United States)

    Kufner, Marco; Brückner, Sabrina; Kammer, Thomas

    Recently, it was reported that the application of a static magnetic field by placing a strong permanent magnet over the scalp for 10 min led to an inhibition of motor cortex excitability for at least 6 min after removing the magnet. When placing the magnet over the somatosensory cortex, a similar inhibitory after effect could be observed as well. Our aim was to replicate the inhibitory effects of transcranial static magnetic field stimulation in the motor and somatosensory system. The modulatory effect of static magnetic field stimulation was investigated in three experiments. In two experiments motor cortex excitability was measured before and after 10 or 15 min of magnet application, respectively. The second experiment included a sham condition and was designed in a double-blinded manner. In a third experiment, paired-pulse SSEPs were measured pre and four times post positioning the magnet over the somatosensory cortex for 10 min on both hemispheres, respectively. The SSEPs of the non stimulated hemisphere served as control condition. We did not observe any systematic effect of the static magnetic field neither on motor cortex excitability nor on SSEPs. Moreover, no SSEP paired-pulse suppression was found. We provide a detailed analysis of possible confounding factors and differences to previous studies on tSMS. After all, our results could not confirm the static magnetic field effect. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  12. Population response characteristics of intrinsic signals in the cat somatosensory cortex following canine mechanical stimulation.

    Science.gov (United States)

    Tao, Jianxiang; Wang, Jian; Li, Zhong; Meng, Jianjun; Yu, Hongbo

    2016-08-04

    Intrinsic signal optical imaging has been widely used to measure functional maps in various sensory cortices due to better spatial resolution and sensitivity for detecting cortical neuroplasticity. However, application of this technique in dentistry has not been reported. In this study, intrinsic signal optical imaging was used to investigate mechanically driven responses in the cat somatosensory cortex, when punctate mechanical stimuli were applied to maxillary canines. The global signal and its spatial organization pattern were obtained. Global signal strength gradually increased with stimulus strength. There was no significant difference in response strength between contralateral and ipsilateral mechanical stimulation. A slightly greater response was recorded in the sigmoidal gyrus than in the coronal gyrus. The cat somatosensory cortex activated by sensory inputs from mechanical stimulation of canines lacks both topographical and functional organization. It is not organized into columns that represent sensory input from each tooth or direction of stimulation. These results demonstrate that intrinsic signal optical imaging is a valid tool for investigating neural responses and neuroplasticity in the somatosensory cortex that represents teeth. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  13. Asymmetric Multisensory Interactions of Visual and Somatosensory Responses in a Region of the Rat Parietal Cortex

    Science.gov (United States)

    Lippert, Michael T.; Takagaki, Kentaroh

    2013-01-01

    Perception greatly benefits from integrating multiple sensory cues into a unified percept. To study the neural mechanisms of sensory integration, model systems are required that allow the simultaneous assessment of activity and the use of techniques to affect individual neural processes in behaving animals. While rodents qualify for these requirements, little is known about multisensory integration and areas involved for this purpose in the rodent. Using optical imaging combined with laminar electrophysiological recordings, the rat parietal cortex was identified as an area where visual and somatosensory inputs converge and interact. Our results reveal similar response patterns to visual and somatosensory stimuli at the level of current source density (CSD) responses and multi-unit responses within a strip in parietal cortex. Surprisingly, a selective asymmetry was observed in multisensory interactions: when the somatosensory response preceded the visual response, supra-linear summation of CSD was observed, but the reverse stimulus order resulted in sub-linear effects in the CSD. This asymmetry was not present in multi-unit activity however, which showed consistently sub-linear interactions. These interactions were restricted to a specific temporal window, and pharmacological tests revealed significant local intra-cortical contributions to this phenomenon. Our results highlight the rodent parietal cortex as a system to model the neural underpinnings of multisensory processing in behaving animals and at the cellular level. PMID:23667650

  14. Study of single and multidigit activation in monkey somatosensory cortex using voltage-sensitive dye imaging.

    Science.gov (United States)

    Roe, Anna Wang; Winberry, Jeremy E; Friedman, Robert M

    2017-07-01

    Toward the goal of understanding cutaneous sensory integration during manual behavior, we used voltage-sensitive dye (VSD) imaging to study the organization and dynamics of anesthetized monkey primary somatosensory cortex (SI) in response to single and multidigit tactile stimulation. We find that in both macaque and squirrel monkey SI, VSD reveals clear focal digit topography consistent with previous electrophysiological and intrinsic signal imaging studies. VSD also reveals interactions in SI in response to multidigit stimulation. With a tactile funneling paradigm in areas 3b and 1 in squirrel monkeys, VSD reveals two-digit induction of subthreshhold influences, consistent with lateral intracortical inhibition. In response to tactile apparent motion stimuli, VSD reveals preferential response to motion stimuli over static tactile stimuli in both areas 1 and 3b. Comparison of the response at different digit locations to "toward digit" stimuli suggests the presence of direction-selective response in area 1; however, further study is needed. These exciting results indicate that VSD constitutes a powerful tool for studying somatosensory cortical processing in nonhuman primates and should be further developed for future somatosensory studies in awake behaving monkeys.

  15. Image-Guided Transcranial Focused Ultrasound Stimulates Human Primary Somatosensory Cortex

    Science.gov (United States)

    Lee, Wonhye; Kim, Hyungmin; Jung, Yujin; Song, In-Uk; Chung, Yong An; Yoo, Seung-Schik

    2015-03-01

    Focused ultrasound (FUS) has recently been investigated as a new mode of non-invasive brain stimulation, which offers exquisite spatial resolution and depth control. We report on the elicitation of explicit somatosensory sensations as well as accompanying evoked electroencephalographic (EEG) potentials induced by FUS stimulation of the human somatosensory cortex. As guided by individual-specific neuroimage data, FUS was transcranially delivered to the hand somatosensory cortex among healthy volunteers. The sonication elicited transient tactile sensations on the hand area contralateral to the sonicated hemisphere, with anatomical specificity of up to a finger, while EEG recordings revealed the elicitation of sonication-specific evoked potentials. Retrospective numerical simulation of the acoustic propagation through the skull showed that a threshold of acoustic intensity may exist for successful cortical stimulation. The neurological and neuroradiological assessment before and after the sonication, along with strict safety considerations through the individual-specific estimation of effective acoustic intensity in situ and thermal effects, showed promising initial safety profile; however, equal/more rigorous precautionary procedures are advised for future studies. The transient and localized stimulation of the brain using image-guided transcranial FUS may serve as a novel tool for the non-invasive assessment and modification of region-specific brain function.

  16. Understanding the role of the primary somatosensory cortex: Opportunities for rehabilitation.

    Science.gov (United States)

    Borich, M R; Brodie, S M; Gray, W A; Ionta, S; Boyd, L A

    2015-12-01

    Emerging evidence indicates impairments in somatosensory function may be a major contributor to motor dysfunction associated with neurologic injury or disorders. However, the neuroanatomical substrates underlying the connection between aberrant sensory input and ineffective motor output are still under investigation. The primary somatosensory cortex (S1) plays a critical role in processing afferent somatosensory input and contributes to the integration of sensory and motor signals necessary for skilled movement. Neuroimaging and neurostimulation approaches provide unique opportunities to non-invasively study S1 structure and function including connectivity with other cortical regions. These research techniques have begun to illuminate casual contributions of abnormal S1 activity and connectivity to motor dysfunction and poorer recovery of motor function in neurologic patient populations. This review synthesizes recent evidence illustrating the role of S1 in motor control, motor learning and functional recovery with an emphasis on how information from these investigations may be exploited to inform stroke rehabilitation to reduce motor dysfunction and improve therapeutic outcomes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Spatio-temporal regulation of the formation of the somatosensory system.

    Science.gov (United States)

    Kawasaki, Hiroshi

    2015-04-01

    The somatosensory system in the brain has been widely used for investigating the mechanisms underlying neural circuit formation and developmental neural plasticity. In the primary somatosensory cortex (S1) of rodents, there are discrete cytoarchitectonic units called barrels. Reverse genetic analyses using knockout mice have revealed molecules that control spatial pattern formation of barrels in S1. Glutamatergic receptors such as the NMDA receptor and mGluR5, and molecules related to serotonin such as serotonin transporter and monoamine oxidase A are essential for the formation of barrels. In addition to the mechanisms of spatial pattern formation, those regulating the timing of developmental processes were uncovered recently. Barrels are formed soon after the birth of newborn mouse pups from their mothers, and it was shown that the timing of barrel formation was determined by the timing of the birth of mouse pups. The mechanisms downstream of birth were also examined. It would be intriguing to examine if the mechanisms found using the somatosensory system are applicable to other brain regions. © 2015 Japanese Society of Developmental Biologists.

  18. Paradigms for restoration of somatosensory feedback via stimulation of the peripheral nervous system.

    Science.gov (United States)

    Pasluosta, Cristian; Kiele, Patrick; Stieglitz, Thomas

    2018-04-01

    The somatosensory system contributes substantially to the integration of multiple sensor modalities into perception. Tactile sensations, proprioception and even temperature perception are integrated to perceive embodiment of our limbs. Damage of somatosensory networks can severely affect the execution of daily life activities. Peripheral injuries are optimally corrected via direct interfacing of the peripheral nerves. Recent advances in implantable devices, stimulation paradigms, and biomimetic sensors enabled the restoration of natural sensations after amputation of the limb. The refinement of stimulation patterns to deliver natural feedback that can be interpreted intuitively such to prescind from long-learning sessions is crucial to function restoration. For this review, we collected state-of-the-art knowledge on the evolution of stimulation paradigms from single fiber stimulation to the eliciting of multisensory sensations. Data from the literature are structured into six sections: (a) physiology of the somatosensory system; (b) stimulation of single fibers; (c) restoral of multisensory percepts; (d) closure of the control loop in hand prostheses; (e) sensory restoration and the sense of embodiment, and (f) methodologies to assess stimulation outcomes. Full functional recovery demands further research on multisensory integration and brain plasticity, which will bring new paradigms for intuitive sensory feedback in the next generation of limb prostheses. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

  19. Modulation of the N30 generators of the somatosensory evoked potentials by the mirror neuron system.

    Science.gov (United States)

    Cebolla, A M; Palmero-Soler, E; Dan, B; Cheron, G

    2014-07-15

    The N30 component of the somatosensory evoked potential is known to be modulated by sensory interference, motor action, movement ideation and observation. We introduce a new paradigm in which the observation task of another person's hand movement triggers the somatosensory stimulus, inducing the N30 response in participants. In order to identify the possible contribution of the mirror neuron network (MNN) to this early sensorimotor processing, we analyzed the N30 topography, the event-related spectral perturbation and the inter-trial coherence on single electroencephalogram (EEG) trials, and we applied swLORETA to localize the N30 sources implicated in the time-frequency domain at rest and during observation, as well as the generators differentiating these two contextual brain states. We found that N30 amplitude increase correlated with increased contralateral precentral alpha, frontal beta, and contralateral frontal gamma power spectrum, and with central and precentral alpha and parietal beta phase-locking of ongoing EEG signals. We demonstrate specific activation of the contralateral post-central and parietal cortex where the angular gyrus (BA39), an important MNN node, is implicated in this enhancement during observation. We conclude that this part of the MNN, involved in proprioceptive processing and more complex body-action representations, is already active prior to somatosensory input and may enhance N30. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. The profile of the recovery cycle in human primary and secondary somatosensory cortex: a magnetoencephalography study.

    Science.gov (United States)

    Hamada, Yasukazu; Otsuka, So; Okamoto, Takashi; Suzuki, Ryoji

    2002-11-01

    To estimate the lifetime of sensory memory in human primary (SI) and secondary (SII) somatosensory cortex with a view to furthering our understanding of the roles played by these cortices in the processing of tactile information. Somatosensory evoked fields (SEFs) were recorded following trains of 5 electrical pulses applied to the right median nerve at the wrist using a whole-head 80 channel magnetoencephalography (MEG) system. Recordings were acquired for trains of pulses with differing interstimulus intervals (ISIs) occurring at 100, 200, 300, 400 and 500 ms. The profile of SEF intensities for the different ISIs provided an estimate of the recovery cycle of evoked neuronal activity, and the time constant of the exponential curve fitted to the recovery cycle was calculated to obtain a putative measure of the lifetime of somatic sensory memory in SI and SII. The estimated time constants were 0.11+/-0.06 s (mean+/-SD) in SI and 0.82+/-0.34 s in SII. The mean time constant in SII was significantly longer than that in SI (Student's paired t test: P=0.021; analysis of variance: F(1,3)=19.7, P=0.021). These data indicate that the lifetime of somatic sensory memory is of longer duration in higher order cortical areas than in primary sensory cortex in the somatosensory information processing system.

  1. Neuronal activity of somatosensory cortex in a cross-modal (visuo-haptic) memory task.

    Science.gov (United States)

    Zhou, Y D; Fuster, J M

    1997-10-01

    Studies have shown that in the monkey's associative cerebral cortex, cells undergo sustained activation of discharge while the animal retains information for a subsequent action. Recent work has revealed the presence of such "memory cells" in the anterior parietal cortex (Brodmann's areas 3a, 3b, 1, and 2)--the early stage of the cortical somatosensory system. Here we inferred that, in a cross-modal visuo-haptic short-term memory task, somatosensory cells would react to visual stimuli associated with tactile features. Single-unit discharge was recorded from the anterior parietal cortex--including areas of hand representation--of monkeys performing a visuo-haptic delayed matching-to-sample task. Units changed firing frequency during the presentation of a visual cue that the animal had to remember for making a correct tactile choice between two objects at the end of a delay (retention period). Some units showed sustained activation during the delay. In some of them that activation differed depending on the cue. These findings suggest that units in somatosensory cortex react to visual stimuli behaviorally associated with tactile information. Further, the results suggest that some of these neurons are involved in short-term active memory and may, therefore, be part of cross-modal memory networks.

  2. Prefrontal cortex and somatosensory cortex in tactile crossmodal association: an independent component analysis of ERP recordings.

    Science.gov (United States)

    Ku, Yixuan; Ohara, Shinji; Wang, Liping; Lenz, Fred A; Hsiao, Steven S; Bodner, Mark; Hong, Bo; Zhou, Yong-Di

    2007-08-22

    Our previous studies on scalp-recorded event-related potentials (ERPs) showed that somatosensory N140 evoked by a tactile vibration in working memory tasks was enhanced when human subjects expected a coming visual stimulus that had been paired with the tactile stimulus. The results suggested that such enhancement represented the cortical activities involved in tactile-visual crossmodal association. In the present study, we further hypothesized that the enhancement represented the neural activities in somatosensory and frontal cortices in the crossmodal association. By applying independent component analysis (ICA) to the ERP data, we found independent components (ICs) located in the medial prefrontal cortex (around the anterior cingulate cortex, ACC) and the primary somatosensory cortex (SI). The activity represented by the IC in SI cortex showed enhancement in expectation of the visual stimulus. Such differential activity thus suggested the participation of SI cortex in the task-related crossmodal association. Further, the coherence analysis and the Granger causality spectral analysis of the ICs showed that SI cortex appeared to cooperate with ACC in attention and perception of the tactile stimulus in crossmodal association. The results of our study support with new evidence an important idea in cortical neurophysiology: higher cognitive operations develop from the modality-specific sensory cortices (in the present study, SI cortex) that are involved in sensation and perception of various stimuli.

  3. Somatosensory cell response to an auditory cue in a haptic memory task.

    Science.gov (United States)

    Zhou, Yong-Di; Fuster, Joaquín M

    2004-08-31

    Neurons in the monkey's anterior parietal cortex (Brodmann's areas 3a, 3b, 1, and 2) have been reported to retain information from a visual cue that has been associated with a tactile stimulus in a haptic memory task. This cross-modal transfer indicates that neurons in somatosensory cortex can respond to non-tactile stimuli if they are associated with tactile information needed for performance of the task. We hypothesized that neurons in somatosensory cortex would be activated by other non-tactile stimuli signaling the haptic movements--of arm and hand--that the task required. We found such cells in anterior parietal areas. They reacted with short-latency activity changes to an auditory signal (a click) that prompted those movements. Further, some of those cells changed their discharge in temporal correlation with the movements themselves, with the touch of the test objects, and with the short-term memory of those objects for subsequent tactile discrimination. These findings suggest that cells in the somatosensory cortex participate in the behavioral integration of auditory stimuli with other sensory stimuli and with motor acts that are associated with those stimuli.

  4. The effect of water immersion on short-latency somatosensory evoked potentials in human

    Directory of Open Access Journals (Sweden)

    Sato Daisuke

    2012-01-01

    Full Text Available Abstract Background Water immersion therapy is used to treat a variety of cardiovascular, respiratory, and orthopedic conditions. It can also benefit some neurological patients, although little is known about the effects of water immersion on neural activity, including somatosensory processing. To this end, we examined the effect of water immersion on short-latency somatosensory evoked potentials (SEPs elicited by median nerve stimuli. Short-latency SEP recordings were obtained for ten healthy male volunteers at rest in or out of water at 30°C. Recordings were obtained from nine scalp electrodes according to the 10-20 system. The right median nerve at the wrist was electrically stimulated with the stimulus duration of 0.2 ms at 3 Hz. The intensity of the stimulus was fixed at approximately three times the sensory threshold. Results Water immersion significantly reduced the amplitudes of the short-latency SEP components P25 and P45 measured from electrodes over the parietal region and the P45 measured by central region. Conclusions Water immersion reduced short-latency SEP components known to originate in several cortical areas. Attenuation of short-latency SEPs suggests that water immersion influences the cortical processing of somatosensory inputs. Modulation of cortical processing may contribute to the beneficial effects of aquatic therapy. Trial Registration UMIN-CTR (UMIN000006492

  5. Chairside intraoral qualitative somatosensory testing: reliability and comparison between patients with atypical odontalgia and healthy controls.

    Science.gov (United States)

    Baad-Hansen, Lene; Pigg, Maria; Ivanovic, Susanne Elmasry; Faris, Hanan; List, Thomas; Drangsholt, Mark; Svensson, Peter

    2013-01-01

    To assess intraoral inter- and intraexaminer reliability of three qualitative measures of intraoral somatosensory function and to compare these measures between patients with atypical odontalgia (AO) and healthy controls. Thirty-one AO patients and 47 healthy controls participated. Inter- and intraexaminer reliability was tested on a subgroup of 46 subjects (25 AO; 21 healthy). Sensitivity to touch, cold, and pinprick stimuli was evaluated on the painful gingival site and the corresponding contralateral site in AO patients, and bilaterally on the gingiva of the first maxillary premolars in controls. Patients were asked to report hypersensitivity, hyposensitivity, or normal sensitivity to stimuli on the painful site compared with the nonpainful site. Kappa values were calculated, and chi-square and Fisher's exact tests were used to compare frequencies between groups. Kappa values ranged between 0.63 and 0.75. The frequency of hypersensitivity to either modality was significantly higher in patients (29% to 61%) than in controls (9% to 17%) (P .057). Only 3.2% of the AO patients had no reports of abnormal sensitivity on any of the tests, compared with 59.6% of the healthy subjects (P < .001). Intraoral qualitative somatosensory testing can detect intraoral sensory disturbances in AO patients, and the reliability is sufficient for initial screening of orofacial somatosensory function.

  6. Seeing is not feeling: posterior parietal but not somatosensory cortex engagement during touch observation.

    Science.gov (United States)

    Chan, Annie W-Y; Baker, Chris I

    2015-01-28

    Observing touch has been reported to elicit activation in human primary and secondary somatosensory cortices and is suggested to underlie our ability to interpret other's behavior and potentially empathy. However, despite these reports, there are a large number of inconsistencies in terms of the precise topography of activation, the extent of hemispheric lateralization, and what aspects of the stimulus are necessary to drive responses. To address these issues, we investigated the localization and functional properties of regions responsive to observed touch in a large group of participants (n = 40). Surprisingly, even with a lenient contrast of hand brushing versus brushing alone, we did not find any selective activation for observed touch in the hand regions of somatosensory cortex but rather in superior and inferior portions of neighboring posterior parietal cortex, predominantly in the left hemisphere. These regions in the posterior parietal cortex required the presence of both brush and hand to elicit strong responses and showed some selectivity for the form of the object or agent of touch. Furthermore, the inferior parietal region showed nonspecific tactile and motor responses, suggesting some similarity to area PFG in the monkey. Collectively, our findings challenge the automatic engagement of somatosensory cortex when observing touch, suggest mislocalization in previous studies, and instead highlight the role of posterior parietal cortex. Copyright © 2015 the authors 0270-6474/15/351468-13$15.00/0.

  7. Asymmetric multisensory interactions of visual and somatosensory responses in a region of the rat parietal cortex.

    Directory of Open Access Journals (Sweden)

    Michael T Lippert

    Full Text Available Perception greatly benefits from integrating multiple sensory cues into a unified percept. To study the neural mechanisms of sensory integration, model systems are required that allow the simultaneous assessment of activity and the use of techniques to affect individual neural processes in behaving animals. While rodents qualify for these requirements, little is known about multisensory integration and areas involved for this purpose in the rodent. Using optical imaging combined with laminar electrophysiological recordings, the rat parietal cortex was identified as an area where visual and somatosensory inputs converge and interact. Our results reveal similar response patterns to visual and somatosensory stimuli at the level of current source density (CSD responses and multi-unit responses within a strip in parietal cortex. Surprisingly, a selective asymmetry was observed in multisensory interactions: when the somatosensory response preceded the visual response, supra-linear summation of CSD was observed, but the reverse stimulus order resulted in sub-linear effects in the CSD. This asymmetry was not present in multi-unit activity however, which showed consistently sub-linear interactions. These interactions were restricted to a specific temporal window, and pharmacological tests revealed significant local intra-cortical contributions to this phenomenon. Our results highlight the rodent parietal cortex as a system to model the neural underpinnings of multisensory processing in behaving animals and at the cellular level.

  8. Childhood Psychosocial Cumulative Risks and Carotid Intima-Media Thickness in Adulthood: The Cardiovascular Risk in Young Finns Study

    Science.gov (United States)

    Hakulinen, Christian; Pulkki-Råback, Laura; Elovainio, Marko; Kubzansky, Laura D.; Jokela, Markus; Hintsanen, Mirka; Juonala, Markus; Kivimäki, Mika; Josefsson, Kim; Hutri-Kähönen, Nina; Kähönen, Mika; Viikari, Jorma; Keltikangas-Järvinen, Liisa; Raitakari, Olli T

    2015-01-01

    Objective Adverse experiences in childhood may influence cardiovascular risk in adulthood. We examined the prospective associations between types of psychosocial adversity as well as having multiple adversities (e.g., cumulative risk) with carotid intima-media thickness (IMT) and its progression among young adults. Higher cumulative risk score in childhood was expected to be associated with higher IMT and its progression. Methods Participants were 2265 men and women (age range: 24-39 years in 2001) from the on-going Cardiovascular Risk in Young Finns study whose carotid IMT were measured in 2001 and 2007. A cumulative psychosocial risk score, assessed at the study baseline in 1980, was derived from four separate aspects of the childhood environment that may impose risk (childhood stressful life-events, parental health behavior family, socioeconomic status, and childhood emotional environment). Results The cumulative risk score was associated with higher IMT in 2007 (b=.004; se=.001; padulthood, including adulthood health behavior, adulthood socioeconomic status and depressive symptoms. Among the individual childhood psychosocial risk categories, having more stressful life-events was associated with higher IMT in 2001 (b=.007; se=.003; p=.016) and poorer parental health behavior predicted higher IMT in 2007 (b=.004; se=.002; p=.031) after adjustment for age, sex and childhood cardiovascular risk factors. Conclusions Early life psychosocial environment influences cardiovascular risk later in life and considering cumulative childhood risk factors may be more informative than individual factors in predicting progression of preclinical atherosclerosis in adulthood. PMID:26809108

  9. Study of cumulative fatigue damage detection for used parts with nonlinear output frequency response functions based on NARMAX modelling

    Science.gov (United States)

    Huang, Honglan; Mao, Hanying; Mao, Hanling; Zheng, Weixue; Huang, Zhenfeng; Li, Xinxin; Wang, Xianghong

    2017-12-01

    Cumulative fatigue damage detection for used parts plays a key role in the process of remanufacturing engineering and is related to the service safety of the remanufactured parts. In light of the nonlinear properties of used parts caused by cumulative fatigue damage, the based nonlinear output frequency response functions detection approach offers a breakthrough to solve this key problem. First, a modified PSO-adaptive lasso algorithm is introduced to improve the accuracy of the NARMAX model under impulse hammer excitation, and then, an effective new algorithm is derived to estimate the nonlinear output frequency response functions under rectangular pulse excitation, and a based nonlinear output frequency response functions index is introduced to detect the cumulative fatigue damage in used parts. Then, a novel damage detection approach that integrates the NARMAX model and the rectangular pulse is proposed for nonlinear output frequency response functions identification and cumulative fatigue damage detection of used parts. Finally, experimental studies of fatigued plate specimens and used connecting rod parts are conducted to verify the validity of the novel approach. The obtained results reveal that the new approach can detect cumulative fatigue damages of used parts effectively and efficiently and that the various values of the based nonlinear output frequency response functions index can be used to detect the different fatigue damages or working time. Since the proposed new approach can extract nonlinear properties of systems by only a single excitation of the inspected system, it shows great promise for use in remanufacturing engineering applications.

  10. Cumulative risks of foster care placement for Danish children.

    Science.gov (United States)

    Fallesen, Peter; Emanuel, Natalia; Wildeman, Christopher

    2014-01-01

    Although recent research suggests that the cumulative risk of foster care placement is far higher for American children than originally suspected, little is known about the cumulative risk of foster care placement in other countries, which makes it difficult to gauge the degree to which factor foster care placement is salient in other contexts. In this article, we provide companion estimates to those provided in recent work on the US by using Danish registry data and synthetic cohort life tables to show how high and unequally distributed the cumulative risk of foster care placement is for Danish children. Results suggest that at the beginning of the study period (in 1998) the cumulative risk of foster care placement for Danish children was roughly in line with the risk for American children. Yet, by the end of the study period (2010), the risk had declined to half the risk for American children. Our results also show some variations by parental ethnicity and sex, but these differences are small. Indeed, they appear quite muted relative to racial/ethnic differences in these risks in the United States. Last, though cumulative risks are similar between Danish and American children (especially at the beginning of the study period), the age-specific risk profiles are markedly different, with higher risks for older Danish children than for older American children.

  11. USING CUMULATIVE NUMBER DENSITIES TO COMPARE GALAXIES ACROSS COSMIC TIME

    Energy Technology Data Exchange (ETDEWEB)

    Behroozi, Peter S.; Wechsler, Risa H. [Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory, Stanford, CA 94305 (United States); Marchesini, Danilo [Department of Physics and Astronomy, Tufts University, Medford, MA 02155 (United States); Muzzin, Adam [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands); Papovich, Casey [Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); Stefanon, Mauro [Physics and Astronomy Department, University of Missouri, Columbia, MO 65211 (United States)

    2013-11-01

    Comparing galaxies across redshifts at fixed cumulative number density is a popular way to estimate the evolution of specific galaxy populations. This method ignores scatter in mass accretion histories and galaxy-galaxy mergers, which can lead to errors when comparing galaxies over large redshift ranges (Δz > 1). We use abundance matching in the ΛCDM paradigm to estimate the median change in cumulative number density with redshift and provide a simple fit (+0.16 dex per unit Δz) for progenitors of z = 0 galaxies. We find that galaxy descendants do not evolve in the same way as galaxy progenitors, largely due to scatter in mass accretion histories. We also provide estimates for the 1σ range of cumulative number densities corresponding to galaxy progenitors and descendants. Finally, we discuss some limits on cumulative number density comparisons, which arise due to difficulties measuring physical quantities (e.g., stellar mass) consistently across redshifts. A public tool to calculate cumulative number density evolution for galaxies, as well as approximate halo masses, is available online.

  12. Maintenance hemodialysis patients have high cumulative radiation exposure.

    LENUS (Irish Health Repository)

    Kinsella, Sinead M

    2010-10-01

    Hemodialysis is associated with an increased risk of neoplasms which may result, at least in part, from exposure to ionizing radiation associated with frequent radiographic procedures. In order to estimate the average radiation exposure of those on hemodialysis, we conducted a retrospective study of 100 patients in a university-based dialysis unit followed for a median of 3.4 years. The number and type of radiological procedures were obtained from a central radiology database, and the cumulative effective radiation dose was calculated using standardized, procedure-specific radiation levels. The median annual radiation dose was 6.9 millisieverts (mSv) per patient-year. However, 14 patients had an annual cumulative effective radiation dose over 20 mSv, the upper averaged annual limit for occupational exposure. The median total cumulative effective radiation dose per patient over the study period was 21.7 mSv, in which 13 patients had a total cumulative effective radiation dose over 75 mSv, a value reported to be associated with a 7% increased risk of cancer-related mortality. Two-thirds of the total cumulative effective radiation dose was due to CT scanning. The average radiation exposure was significantly associated with the cause of end-stage renal disease, history of ischemic heart disease, transplant waitlist status, number of in-patient hospital days over follow-up, and death during the study period. These results highlight the substantial exposure to ionizing radiation in hemodialysis patients.

  13. The neural dynamics of somatosensory processing and adaptation across childhood: a high-density electrical mapping study

    Science.gov (United States)

    Uppal, Neha; Foxe, John J.; Butler, John S.; Acluche, Frantzy

    2016-01-01

    Young children are often hyperreactive to somatosensory inputs hardly noticed by adults, as exemplified by irritation to seams or labels in clothing. The neurodevelopmental mechanisms underlying changes in sensory reactivity are not well understood. Based on the idea that neurodevelopmental changes in somatosensory processing and/or changes in sensory adaptation might underlie developmental differences in somatosensory reactivity, high-density electroencephalography was used to examine how the nervous system responds and adapts to repeated vibrotactile stimulation over childhood. Participants aged 6–18 yr old were presented with 50-ms vibrotactile stimuli to the right wrist over the median nerve at 5 blocked interstimulus intervals (ranging from ∼7 to ∼1 stimulus per second). Somatosensory evoked potentials (SEPs) revealed three major phases of activation within the first 200 ms, with scalp topographies suggestive of neural generators in contralateral somatosensory cortex. Although overall SEPs were highly similar for younger, middle, and older age groups (6.1–9.8, 10.0–12.9, and 13.0–17.8 yr old), there were significant age-related amplitude differences in initial and later phases of the SEP. In contrast, robust adaptation effects for fast vs. slow presentation rates were observed that did not differ as a function of age. A greater amplitude response in the later portion of the SEP was observed for the youngest group and may be related to developmental changes in responsivity to somatosensory stimuli. These data suggest the protracted development of the somatosensory system over childhood, whereas adaptation, as assayed in this study, is largely in place by ∼7 yr of age. PMID:26763781

  14. Distinct α- and β-band rhythms over rat somatosensory cortex with similar properties as in humans.

    Science.gov (United States)

    Fransen, Anne M M; Dimitriadis, George; van Ede, Freek; Maris, Eric

    2016-06-01

    We demonstrate distinct α- (7-14 Hz) and β-band (15-30 Hz) rhythms in rat somatosensory cortex in vivo using epidural electrocorticography recordings. Moreover, we show in rats that a genuine β-rhythm coexists alongside β-activity that reflects the second harmonic of the arch-shaped somatosensory α-rhythm. This demonstration of a genuine somatosensory β-rhythm depends on a novel quantification of neuronal oscillations that is based on their rhythmic nature: lagged coherence. Using lagged coherence, we provide two lines of evidence that this somatosensory β-rhythm is distinct from the second harmonic of the arch-shaped α-rhythm. The first is based on the rhythms' spatial properties: the α- and β-rhythms are demonstrated to have significantly different topographies. The second is based on the rhythms' temporal properties: the lagged phase-phase coupling between the α- and β-rhythms is demonstrated to be significantly less than would be expected if both reflected a single underlying nonsinusoidal rhythm. Finally, we demonstrate that 1) the lagged coherence spectrum is consistent between signals from rat and human somatosensory cortex; and 2) a tactile stimulus has the same effect on the somatosensory α- and β-rhythms in both rats and humans, namely suppressing them. Thus we not only provide evidence for the existence of genuine α- and β-rhythms in rat somatosensory cortex, but also for their homology to the primate sensorimotor α- and β-rhythms. Copyright © 2016 the American Physiological Society.

  15. The neural dynamics of somatosensory processing and adaptation across childhood: a high-density electrical mapping study.

    Science.gov (United States)

    Uppal, Neha; Foxe, John J; Butler, John S; Acluche, Frantzy; Molholm, Sophie

    2016-03-01

    Young children are often hyperreactive to somatosensory inputs hardly noticed by adults, as exemplified by irritation to seams or labels in clothing. The neurodevelopmental mechanisms underlying changes in sensory reactivity are not well understood. Based on the idea that neurodevelopmental changes in somatosensory processing and/or changes in sensory adaptation might underlie developmental differences in somatosensory reactivity, high-density electroencephalography was used to examine how the nervous system responds and adapts to repeated vibrotactile stimulation over childhood. Participants aged 6-18 yr old were presented with 50-ms vibrotactile stimuli to the right wrist over the median nerve at 5 blocked interstimulus intervals (ranging from ∼7 to ∼1 stimulus per second). Somatosensory evoked potentials (SEPs) revealed three major phases of activation within the first 200 ms, with scalp topographies suggestive of neural generators in contralateral somatosensory cortex. Although overall SEPs were highly similar for younger, middle, and older age groups (6.1-9.8, 10.0-12.9, and 13.0-17.8 yr old), there were significant age-related amplitude differences in initial and later phases of the SEP. In contrast, robust adaptation effects for fast vs. slow presentation rates were observed that did not differ as a function of age. A greater amplitude response in the later portion of the SEP was observed for the youngest group and may be related to developmental changes in responsivity to somatosensory stimuli. These data suggest the protracted development of the somatosensory system over childhood, whereas adaptation, as assayed in this study, is largely in place by ∼7 yr of age. Copyright © 2016 the American Physiological Society.

  16. Corticofugal projections induce long-lasting effects on somatosensory responses in the trigeminal complex of the rat

    Directory of Open Access Journals (Sweden)

    Angel eNunez

    2014-05-01

    Full Text Available The sensory information flow at subcortical relay stations is controlled by the action of topographic connections from the neocortex. To determinate the functional properties of the somatosensory corticofugal projections to the principal (Pr5 and caudal spinal (Sp5C trigeminal nuclei, we performed unitary recordings in anesthetized rats. To examine the effect of these cortical projections we used tactile stimulation of the whisker and electrical stimulation of somatosensory cortices. Corticofugal anatomical projections to Pr5 and Sp5C nuclei were detected by using retrograde fluorescent tracers. Neurons projecting exclusively to Pr5 were located in the cingulate cortex while neurons projecting to both Sp5C and Pr5 nuclei were located in the somatosensory and insular cortices (>75% of neurons. Physiological results indicated that primary somatosensory cortex produced a short-lasting facilitating or inhibiting effects (< 5 minutes of tactile responses in Pr5 nucleus through activation of NMDA glutamatergic or GABAA receptors since effects were blocked by iontophoretically application of APV and bicuculline, respectively. In contrast, stimulation of secondary somatosensory cortex did not affect most of the Pr5 neurons; however both cortices inhibited the nociceptive responses in the Sp5C nucleus through activation of glycinergic or GABAA receptors because effects were blocked by iontophoretically application of strychnine and bicuculline, respectively. These and anatomical results demonstrated that the somatosensory cortices projects to Pr5 nucleus to modulate tactile responses by excitatory and inhibitory actions, while projections to the Sp5C nucleus control nociceptive sensory transmission by only inhibitory effects. Thus, somatosensory cortices may modulate innocuous and noxious inputs simultaneously, contributing to the perception of specifically tactile or painful sensations.

  17. Baltic Sea biodiversity status vs. cumulative human pressures

    DEFF Research Database (Denmark)

    Andersen, Jesper H.; Halpern, Benjamin S.; Korpinen, Samuli

    2015-01-01

    Abstract Many studies have tried to explain spatial and temporal variations in biodiversity status of marine areas from a single-issue perspective, such as fishing pressure or coastal pollution, yet most continental seas experience a wide range of human pressures. Cumulative impact assessments have...... been developed to capture the consequences of multiple stressors for biodiversity, but the ability of these assessments to accurately predict biodiversity status has never been tested or ground-truthed. This relationship has similarly been assumed for the Baltic Sea, especially in areas with impaired...... status, but has also never been documented. Here we provide a first tentative indication that cumulative human impacts relate to ecosystem condition, i.e. biodiversity status, in the Baltic Sea. Thus, cumulative impact assessments offer a promising tool for informed marine spatial planning, designation...

  18. Session: What do we know about cumulative or population impacts

    Energy Technology Data Exchange (ETDEWEB)

    Kerlinger, Paul; Manville, Al; Kendall, Bill

    2004-09-01

    This session at the Wind Energy and Birds/Bats workshop consisted of a panel discussion followed by a discussion/question and answer period. The panelists were Paul Kerlinger, Curry and Kerlinger, LLC, Al Manville, U.S. Fish and Wildlife Service, and Bill Kendall, US Geological Service. The panel addressed the potential cumulative impacts of wind turbines on bird and bat populations over time. Panel members gave brief presentations that touched on what is currently known, what laws apply, and the usefulness of population modeling. Topics addressed included which sources of modeling should be included in cumulative impacts, comparison of impacts from different modes of energy generation, as well as what research is still needed regarding cumulative impacts of wind energy development on bird and bat populations.

  19. Solid-state electro-cumulation effect numerical simulation

    CERN Document Server

    Grishin, V G

    2001-01-01

    It is an attempt to simulate as really as possible a crystal's interatomic interaction under conditions of "Solid-state electro-cumulation (super-polarization) effect". Some theoretical and experimental reasons to believe that within solid substances an interparticles interaction could concentrate from the surface to a centre were given formerly. Now, numerical results show the conditions that could make the cumulation more effective. Another keywords: ion, current, solid, symmetry, cumulation, polarization, depolarization, ionic conductor,superionic conductor, ice, crystal, strain, V-center, V-centre, doped crystal, interstitial impurity, intrinsic color center, high pressure technology, Bridgman, anvil, experiment, crowdion, dielectric, proton, layer, defect, lattice, dynamics, electromigration, mobility, muon catalysis, concentration, doping, dopant, conductivity, pycnonuclear reaction, permittivity, dielectric constant, point defects, interstitials, polarizability, imperfection, defect centers, glass, epi...

  20. Evolutionary neural network modeling for software cumulative failure time prediction

    International Nuclear Information System (INIS)

    Tian Liang; Noore, Afzel

    2005-01-01

    An evolutionary neural network modeling approach for software cumulative failure time prediction based on multiple-delayed-input single-output architecture is proposed. Genetic algorithm is used to globally optimize the number of the delayed input neurons and the number of neurons in the hidden layer of the neural network architecture. Modification of Levenberg-Marquardt algorithm with Bayesian regularization is used to improve the ability to predict software cumulative failure time. The performance of our proposed approach has been compared using real-time control and flight dynamic application data sets. Numerical results show that both the goodness-of-fit and the next-step-predictability of our proposed approach have greater accuracy in predicting software cumulative failure time compared to existing approaches

  1. Learning curve for fetoscopic laser surgery using cumulative sum analysis.

    Science.gov (United States)

    Peeters, Suzanne H P; Van Zwet, Erik W; Oepkes, Dick; Lopriore, Enrico; Klumper, Frans J; Middeldorp, Johanna M

    2014-07-01

    To identify a learning curve and monitor operator performance for fetoscopic laser surgery for twin-to-twin transfusion syndrome using cumulative sum analysis. Retrospective cohort study. National tertiary referral center for invasive fetal therapy. A total of 340 consecutive monochorionic pregnancies with twin-to-twin transfusion syndrome treated with fetoscopic laser coagulation between August 2000 and December 2010. A learning curve was generated using learning curve cumulative sum analysis and cumulative sum methodology to assess changes in double survival across the case sequence. Laser surgery was initially performed by two operators, joined by a third and fourth operator after 1 and 2 years, respectively. Individual operator performance, double perinatal survival at 4 weeks. Overall survival of both twins occurred in 59% (201/340), median gestational age at birth was 32.0 weeks. Cumulative sum graphs showed that level of competence for double survival for the operators was reached after 26, 25, 26, and 35 procedures, respectively. Two operators kept their competence level and continued to improve after completing the initial learning process; two others went out of control at one point in time, according to the cumulative sum boundaries. A difference in learning effect was associated with number of procedures performed annually and previous experience with other ultrasound-guided invasive procedures. This study shows that all operators reached a level of competence after at least 25 fetoscopic laser procedures and confirms the value of using the cumulative sum method both for learning curve assessment and for ongoing quality control. © 2014 Nordic Federation of Societies of Obstetrics and Gynecology.

  2. Cumulative carbon as a policy framework for achieving climate stabilization

    Science.gov (United States)

    Matthews, H. Damon; Solomon, Susan; Pierrehumbert, Raymond

    2012-01-01

    The primary objective of the United Nations Framework Convention on Climate Change is to stabilize greenhouse gas concentrations at a level that will avoid dangerous climate impacts. However, greenhouse gas concentration stabilization is an awkward framework within which to assess dangerous climate change on account of the significant lag between a given concentration level and the eventual equilibrium temperature change. By contrast, recent research has shown that global temperature change can be well described by a given cumulative carbon emissions budget. Here, we propose that cumulative carbon emissions represent an alternative framework that is applicable both as a tool for climate mitigation as well as for the assessment of potential climate impacts. We show first that both atmospheric CO2 concentration at a given year and the associated temperature change are generally associated with a unique cumulative carbon emissions budget that is largely independent of the emissions scenario. The rate of global temperature change can therefore be related to first order to the rate of increase of cumulative carbon emissions. However, transient warming over the next century will also be strongly affected by emissions of shorter lived forcing agents such as aerosols and methane. Non-CO2 emissions therefore contribute to uncertainty in the cumulative carbon budget associated with near-term temperature targets, and may suggest the need for a mitigation approach that considers separately short- and long-lived gas emissions. By contrast, long-term temperature change remains primarily associated with total cumulative carbon emissions owing to the much longer atmospheric residence time of CO2 relative to other major climate forcing agents. PMID:22869803

  3. Cumulative social risk and obesity in early childhood.

    Science.gov (United States)

    Suglia, Shakira F; Duarte, Cristiane S; Chambers, Earle C; Boynton-Jarrett, Renée

    2012-05-01

    The goal of this study was to examine the relationship between cumulative social adversity and childhood obesity among preschool-aged children (N = 1605) in the Fragile Families and Child Wellbeing Study. Maternal reports of intimate partner violence, food insecurity, housing insecurity, maternal depressive symptoms, maternal substance use, and father's incarceration were obtained when the child was 1 and 3 years of age. Two cumulative social risk scores were created by summing the 6 factors assessed at ages 1 and 3 years. Child height and weight were measured at 5 years of age. Logistic regression models stratified according to gender were used to estimate the association between cumulative social risk and obesity, adjusting for sociodemographic factors. Seventeen percent of children were obese at age 5 years, and 57% had at least 1 social risk factor. Adjusting for sociodemographic factors, girls experiencing high cumulative social risk (≥2 factors) at age 1 year only (odds ratio [OR]: 2.1 [95% confidence interval [CI]: 1.1-4.1]) or at 3 years only (OR: 2.2 [95% CI: 1.2-4.2]) were at increased odds of being obese compared with girls with no risk factors at either time point. Those experiencing high cumulative risk at age 1 and 3 years were not at statistically significant odds of being obese (OR: 1.9 [95% CI: 0.9-4.0]). No significant associations were noted among boys. There seems to be gender differences in the effects of cumulative social risk factors on the prevalence of obesity at 5 years of age. Understanding the social context of families could make for more effective preventive efforts to combat childhood obesity.

  4. A study of cumulative fatigue damage in AISI 4130 steel

    Science.gov (United States)

    Jeelani, S.; Musial, M.

    1986-01-01

    Experimental data were obtained using AISI 4130 steel under stress ratios of -1 and 0. A study of cumulative fatigue damage using Miner's and Kramer's equations for stress ratios of -1 and 0 for low-high, low-high-mixed, high-low, and high-low-mixed stress sequences has revealed that there is a close agreement between the theoretical and experimental values of fatigue damage and fatigue life. Kramer's equation predicts less conservative and more realistic cumulative fatigue damage than the popularly used Miner's rule does.

  5. The role of factorial cumulants in reactor neutron noise theory

    International Nuclear Information System (INIS)

    Colombino, A.; Pacilio, N.; Sena, G.

    1979-01-01

    The physical meaning and the combinatorial implications of the factorial cumulant of a state variable such as the number of neutrons or the number of neutron counts are specified. Features of the presentation are: (1) the fission process is treated in its entirety without the customary binary emission restriction, (b) the introduction of the factorial cumulants helps in reducing the complexity of the mathematical problems, (c) all the solutions can be obtained analytically. Only the ergodic hypothesis for the neutron population evolution is dealt with. (author)

  6. Cumulative Incidence of Cancer After Solid Organ Transplantation

    Science.gov (United States)

    Hall, Erin C.; Pfeiffer, Ruth M.; Segev, Dorry L.; Engels, Eric A.

    2014-01-01

    BACKGROUND Solid organ transplantation recipients have elevated cancer incidence. Estimates of absolute cancer risk after transplantation can inform prevention and screening. METHODS The Transplant Cancer Match Study links the US transplantation registry with 14 state/regional cancer registries. The authors used nonparametric competing risk methods to estimate the cumulative incidence of cancer after transplantation for 2 periods (1987–1999 and 2000–2008). For recipients from 2000 to 2008, the 5-year cumulative incidence, stratified by organ, sex, and age at transplantation, was estimated for 6 preventable or screen-detectable cancers. For comparison, the 5-year cumulative incidence was calculated for the same cancers in the general population at representative ages using Surveillance, Epidemiology, and End Results data. RESULTS Among 164,156 recipients, 8520 incident cancers were identified. The absolute cancer risk was slightly higher for recipients during the period from 2000 to 2008 than during the period from 1987 to 1999 (5-year cumulative incidence: 4.4% vs 4.2%; P =.006); this difference arose from the decreasing risk of competing events (5-year cumulative incidence of death, graft failure, or retransplantation: 26.6% vs 31.9%; P 50 years; range, 0.36%–2.22%). For recipients aged >50 years, the 5-year cumulative incidence was higher for colorectal cancer (range, 0.33%–1.94%) than for the general population at the recommended screening age (aged 50 years: range, 0.25%–0.33%). For recipients aged >50 years, the 5-year cumulative incidence was high for lung cancer among thoracic organ recipients (range, 1.16%–3.87%) and for kidney cancer among kidney recipients (range, 0.53%–0.84%). The 5-year cumulative incidence for prostate cancer and breast cancer was similar or lower in transplantation recipients than at the recommended ages of screening in the general population. CONCLUSIONS Subgroups of transplantation recipients have a high absolute risk

  7. Fractional Fokker-Planck equation and oscillatory behavior of cumulant moments

    International Nuclear Information System (INIS)

    Suzuki, N.; Biyajima, M.

    2002-01-01

    The Fokker-Planck equation is considered, which is connected to the birth and death process with immigration by the Poisson transform. The fractional derivative in time variable is introduced into the Fokker-Planck equation in order to investigate an origin of oscillatory behavior of cumulant moments. From its solution (the probability density function), the generating function (GF) for the corresponding probability distribution is derived. We consider the case when the GF reduces to that of the negative binomial distribution (NBD), if the fractional derivative is replaced to the ordinary one. The H j moment derived from the GF of the NBD decreases monotonically as the rank j increases. However, the H j moment derived in our approach oscillates, which is contrasted with the case of the NBD. Calculated H j moments are compared with those of charged multiplicities observed in pp-bar, e + e - , and e + p collisions. A phenomenological meaning of introducing the fractional derivative in time variable is discussed

  8. Ethosuximide Affects Paired-Pulse Facilitation in Somatosensory Cortex of WAG\\Rij Rats as a Model of Absence Seizure.

    Science.gov (United States)

    Ghamkhari Nejad, Ghazaleh; Shahabi, Parviz; Alipoor, Mohamad Reza; Ghaderi Pakdel, Firouz; Asghari, Mohammad; Sadighi Alvandi, Mina

    2015-11-01

    The interaction between somatosensory cortex and thalamus via a thalamocortical loop is a theory behind induction of absence epilepsy. Inside peri-oral somatosensory (S1po) and primary somatosensory forelimb (S1fl) regions, excitatory and inhibitory systems are not balanced and GABAergic inhibitory synapses seem to play a fundamental role in short-term plasticity alterations. We investigated the effects of Ethosuximide on presynaptic changes by utilizing paired-pulse stimulation that was recorded from somatosensory cortex in 18 WAG\\Rij rats during epileptic activity. A twisted tripolar electrode including two stimulating electrodes and one recording electrode was implanted into the S1po and S1FL according to stereotaxic landmarks. Paired-pulses (200 µs, 100-1000 µA, 0.1 Hz) were applied to somatosensory cortex at 50, 100, 400, 500 ms inter-pulse intervals for 50 min period. The results showed that paired-pulse facilitation was significantly reduced at all intervals in all times, but compared to the control group of epileptic WAG/Rij rats (psomatosensory cortex inhibitory loops by alteration in GABA levels that leads to a markedly diminished PPF in paired-pulse stimulation.

  9. The attentional-relevance and temporal dynamics of visual-tactile crossmodal interactions differentially influence early stages of somatosensory processing.

    Science.gov (United States)

    Popovich, Christina; Staines, W Richard

    2014-03-01

    Crossmodal interactions between relevant visual and tactile inputs can enhance attentional modulation at early stages in somatosensory cortices to achieve goal-oriented behaviors. However, the specific contribution of each sensory system during attentional processing remains unclear. We used EEG to investigate the effects of visual priming and attentional relevance in modulating somatosensory cortical responses. Healthy adults performed a sensory integration task that required scaled motor responses dependent on the amplitudes of tactile and visual stimuli. Participants completed an attentional paradigm comprised of 5 conditions that presented sequential or concurrent pairs of discrete stimuli with random amplitude variations: 1) tactile-tactile (TT), 2) visual-visual (VV), 3) visual-tactile simultaneous (SIM), 4) tactile-visual delay (TVd), and 5) visual-tactile delay (VTd), each with a 100 ms temporal delay between stimulus onsets. Attention was directed to crossmodal conditions and graded motor responses representing the summation of the 2 stimulus amplitudes were made. Results of somatosensory ERPs showed that the modality-specific components (P50, P100) were sensitive to i) the temporal dynamics of crossmodal interactions, and ii) the relevance of these sensory signals for behaviour. Notably, the P50 amplitude was greatest in the VTd condition, suggesting that presentation of relevant visual information for upcoming movement modulates somatosensory processing in modality-specific cortical regions, as early as the primary somatosensory cortex (SI).

  10. Somatosensory sensitivity in patients with persistent idiopathic orofacial pain is associated with pain relief from hypnosis and relaxation.

    Science.gov (United States)

    Baad-Hansen, Lene; Abrahamsen, Randi; Zachariae, Robert; List, Thomas; Svensson, Peter

    2013-06-01

    In a recent study hypnosis has been found to relieve persistent idiopathic orofacial pain. Quantitative sensory testing (QST) is widely used to evaluate somatosensory sensitivity, which has been suggested as a possible predictor of management outcome. The objectives of this study were to examine: (1) possible associations between clinical pain relief and baseline somatosensory sensitivity and (2) the effect of hypnosis management on QST parameters. Forty-one patients with persistent idiopathic orofacial pain completed this randomized controlled study in 1 of 2 groups: hypnosis (hypnotic analgesia suggestions) or control (relaxation). QST at 2 intraoral (pain region and contralateral mirror image region) and 3 extraoral (hand and both cheeks) sites was performed at baseline and after the hypnosis/control management, together with pressure pain thresholds and pressure pain tolerance thresholds determined bilaterally at the masseter and temporalis muscles, the temporomandibular joints, and the third finger. Degree of pain relief was negatively correlated with a summary statistic of baseline somatosensory sensitivity (summed z-score), that is, high baseline somatosensory sensitivity was associated with low pain relief (r=-0.372, P=0.020). Hypnosis had no major effect on any QST measure compared with relaxation (P>0.063). High pain sensitivity at baseline may predict poor pain management outcome. In addition, despite clear clinical pain relief, hypnosis did not significantly or specifically influence somatosensory sensitivity. Future studies should further explore QST measures as possible predictors of different management response in orofacial pain conditions.

  11. Somatosensory processing and schizophrenia liability: proprioception, exteroceptive sensitivity, and graphesthesia performance in the biological relatives of schizophrenia patients.

    Science.gov (United States)

    Chang, Bernard P; Lenzenweger, Mark F

    2005-02-01

    In the present study, the authors examined somatosensory processing in 30 biological relatives of persons with schizophrenia (hereafter called "schizophrenia relatives"), 30 biological relatives of persons with bipolar affective disorder (psychiatric family control subjects), and 30 healthy control subjects with no family history of psychopathology. All 3 groups completed a weight discrimination task, a 2-point discrimination task, and a complex cognitive somatosensory task (i.e., graphesthesia). The schizophrenia relatives performed significantly worse on all 3 somatosensory tasks compared with both the healthy control subjects and the bipolar relatives. The healthy control subjects and psychiatric family control subjects showed no significant differences on any of the somatosensory tasks. Within the weight discrimination and 2-point discrimination tasks, schizophrenia relatives showed group differences on the d' index, the measure of sensitivity, whereas all 3 groups did not differ on lnbeta, the measure of response bias, suggesting a genuine difference in weight and touch sensitivity. The d' value of the weight discrimination task was significantly associated with both the cognitive-perceptual factor and negative symptom factor of the clinical questionnaire (e.g., Schizotypal Personality Questionnaire; SPQ), whereas the 2-point discrimination d' value and graphesthesia scores were significantly associated only with the cognitive-perceptual factor of the SPQ. Implications for the possible relation between somatosensory task performance and schizophrenia liability are discussed. Copyright (c) 2005 APA, all rights reserved.

  12. Automatic auditory and somatosensory brain responses in relation to cognitive abilities and physical fitness in older adults.

    Science.gov (United States)

    Strömmer, Juho M; Põldver, Nele; Waselius, Tomi; Kirjavainen, Ville; Järveläinen, Saara; Björksten, Sanni; Tarkka, Ina M; Astikainen, Piia

    2017-10-20

    In normal ageing, structural and functional changes in the brain lead to an altered processing of sensory stimuli and to changes in cognitive functions. The link between changes in sensory processing and cognition is not well understood, but physical fitness is suggested to be beneficial for both. We recorded event-related potentials to somatosensory and auditory stimuli in a passive change detection paradigm from 81 older and 38 young women and investigated their associations with cognitive performance. In older adults also associations to physical fitness were studied. The somatosensory mismatch response was attenuated in older adults and it associated with executive functions. Somatosensory P3a did not show group differences, but in older adults, it associated with physical fitness. Auditory N1 and P2 responses to repetitive stimuli were larger in amplitude in older than in young adults. There were no group differences in the auditory mismatch negativity, but it associated with working memory capacity in young but not in older adults. Our results indicate that in ageing, changes in stimulus encoding and deviance detection are observable in electrophysiological responses to task-irrelevant somatosensory and auditory stimuli, and the higher somatosensory response amplitudes are associated with better executive functions and physical fitness.

  13. Relationship between somatosensory event-related potential N140 aberrations and hemispatial agnosia in patients with stroke: a preliminary study.

    Science.gov (United States)

    Ueno, Tomoyuki; Hada, Yasushi; Shimizu, Yukiyo; Yamada, Thoru

    2018-06-01

    The somatosensory event-related potential N140 is thought to be related to selective attention. This study aimed to compare the somatosensory event-related potential N140 in healthy subjects to that in patients with stroke to determine whether N140 and attentiveness are associated in patients with stroke with or without hemispatial agnosia. Normal somatosensory event-related potential N140 values were determined using data from ten healthy subjects. Fifteen patients with stroke were divided into two groups based on the presence of hemispatial neglect. Somatosensory event-related potential N140 components were compared between the two groups. Stimulation of the affected limb in the hemispatial agnosia group resulted in significantly longer N140 latency at the contralateral vs. the ipsilateral electrode. This was the inverse of the relationship observed in normal subjects, with stimulation of the intact side in patients with hemispatial agnosia, and with stimulation of both the intact and affected sides in patients without agnosia. In the hemispatial agnosia group, the peak latency of N140 following stimulation of the affected side was significantly longer than it was following stimulation of the intact side and when compared to that in patients without agnosia. In addition, abnormal N140 peak latencies were observed at the Cz and ipsilateral electrodes in patients with hemispatial agnosia following stimulation of the intact side. These findings suggest that somatosensory event-related potential N140 is independently generated in each hemisphere and may reflect cognitive attention.

  14. Enhancement of Median Nerve Regeneration by Mesenchymal Stem Cells Engraftment in an Absorbable Conduit: Improvement of Peripheral Nerve Morphology with Enlargement of Somatosensory Cortical Representation.

    Directory of Open Access Journals (Sweden)

    Julia Teixeira Oliveira

    2014-10-01

    Full Text Available We studied the morphology and the cortical representation of the median nerve (MN, 10 weeks after a transection immediately followed by treatment with tubulization using a polycaprolactone (PCL conduit with or without bone marrow-derived mesenchymal stem cell (MSC transplant. In order to characterize the cutaneous representation of MN inputs in primary somatosensory cortex (S1, electrophysiological cortical mapping of the somatosensory representation of the forepaw and adjacent body parts was performed after acute lesion of all brachial plexus nerves, except for the MN. This was performed in ten adult male Wistar rats randomly assigned in 3 groups: MN Intact (n=4, PCL-Only (n=3 and PCL+MSC (n=3. Ten weeks before mapping procedures in animals from PCL-Only and PCL+MSC groups, animal were subjected to MN transection with removal of a 4-mm-long segment, immediately followed by suturing a PCL conduit to the nerve stumps with (PCL+MSC group or without (PCL-Only group injection of MSC into the conduit. After mapping the representation of the MN in S1, animals had a segment of the regenerated nerve processed for light and transmission electron microscopy. For histomorphometric analysis of the nerve segment, sample size was increased to 5 animals per experimental group. The PCL+MSC group presented a higher number of myelinated fibers and a larger cortical representation of MN inputs in S1 (3,383±390 fibers; 2.3 mm2, respectively than the PCL-Only group (2,226±575 fibers; 1.6 mm2. In conclusion, MSC-based therapy associated with PCL conduits can improve MN regeneration. This treatment seems to rescue the nerve representation in S1, thus minimizing the stabilization of new representations of adjacent body parts in regions previously responsive to the MN.

  15. Cumulative assessment : Strategic choices to influence students' study effort

    NARCIS (Netherlands)

    Kerdijk, Wouter; Tio, Rene A.; Mulder, B. Florentine; Cohen-Schotanus, Janke

    2013-01-01

    Background: It has been asserted that assessment can and should be used to drive students' learning. In the current study, we present a cumulative assessment program in which test planning, repeated testing and compensation are combined in order to influence study effort. The program is aimed at

  16. Cumulative assessment: does it improve students’ knowledge acquisition and retention?

    NARCIS (Netherlands)

    Cecilio Fernandes, Dario; Nagtegaal, Manouk; Noordzij, Gera; Tio, Rene

    2017-01-01

    Introduction Assessment for learning means changing students’ behaviour regarding their learning. Cumulative assessment has been shown to increase students’ self-study time and spread their study time throughout a course. However, there was no difference regarding students’ knowledge at the end of

  17. Variable Cultural Acquisition Costs Constrain Cumulative Cultural Evolution

    Science.gov (United States)

    Mesoudi, Alex

    2011-01-01

    One of the hallmarks of the human species is our capacity for cumulative culture, in which beneficial knowledge and technology is accumulated over successive generations. Yet previous analyses of cumulative cultural change have failed to consider the possibility that as cultural complexity accumulates, it becomes increasingly costly for each new generation to acquire from the previous generation. In principle this may result in an upper limit on the cultural complexity that can be accumulated, at which point accumulated knowledge is so costly and time-consuming to acquire that further innovation is not possible. In this paper I first review existing empirical analyses of the history of science and technology that support the possibility that cultural acquisition costs may constrain cumulative cultural evolution. I then present macroscopic and individual-based models of cumulative cultural evolution that explore the consequences of this assumption of variable cultural acquisition costs, showing that making acquisition costs vary with cultural complexity causes the latter to reach an upper limit above which no further innovation can occur. These models further explore the consequences of different cultural transmission rules (directly biased, indirectly biased and unbiased transmission), population size, and cultural innovations that themselves reduce innovation or acquisition costs. PMID:21479170

  18. Cumulative hip contact stress predicts osteoarthritis in DDH.

    Science.gov (United States)

    Mavcic, Blaz; Iglic, Ales; Kralj-Iglic, Veronika; Brand, Richard A; Vengust, Rok

    2008-04-01

    Hip stresses are generally believed to influence whether a hip develops osteoarthritis (OA); similarly, various osteotomies have been proposed to reduce contact stresses and the risk of OA. We asked whether elevated hip contact stress predicted osteoarthritis in initially asymptomatic human hips. We identified 58 nonoperatively treated nonsubluxated hips with developmental dysplasia (DDH) without symptoms at skeletal maturity; the control group included 48 adult hips without hip disease. The minimum followup was 20 years (mean, 29 years; range, 20-41 years). Peak contact stress was computed with the HIPSTRESS method using anteroposterior pelvic radiographs at skeletal maturity. The cumulative contact stress was determined by multiplying the peak contact stress by age at followup. We compared WOMAC scores and radiographic indices of OA. Dysplastic hips had higher mean peak contact and higher mean cumulative contact stress than normal hips. Mean WOMAC scores and percentage of asymptomatic hips in the study group (mean age 51 years) were similar to those in the control group (mean age 68 years). After adjusting for gender and age, the cumulative contact stress, Wiberg center-edge angle, body mass index, but not the peak contact stress, independently predicted the final WOMAC score in dysplastic hips but not in normal hips. Cumulative contact stress predicted early hip OA better than the Wiberg center-edge angle. Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

  19. The proportional odds cumulative incidence model for competing risks

    DEFF Research Database (Denmark)

    Eriksson, Frank; Li, Jianing; Scheike, Thomas

    2015-01-01

    We suggest an estimator for the proportional odds cumulative incidence model for competing risks data. The key advantage of this model is that the regression parameters have the simple and useful odds ratio interpretation. The model has been considered by many authors, but it is rarely used in pr...

  20. How to manage the cumulative flood safety of catchment dams ...

    African Journals Online (AJOL)

    Dam safety is a significant issue being taken seriously worldwide. However, in Australia, although much attention is being devoted to the medium- to large-scale dams, minimal attention is being paid to the serious potential problems associated with smaller dams, particularly the potential cumulative safety threats they pose ...

  1. Hyperscaling breakdown and Ising spin glasses: The Binder cumulant

    Science.gov (United States)

    Lundow, P. H.; Campbell, I. A.

    2018-02-01

    Among the Renormalization Group Theory scaling rules relating critical exponents, there are hyperscaling rules involving the dimension of the system. It is well known that in Ising models hyperscaling breaks down above the upper critical dimension. It was shown by Schwartz (1991) that the standard Josephson hyperscaling rule can also break down in Ising systems with quenched random interactions. A related Renormalization Group Theory hyperscaling rule links the critical exponents for the normalized Binder cumulant and the correlation length in the thermodynamic limit. An appropriate scaling approach for analyzing measurements from criticality to infinite temperature is first outlined. Numerical data on the scaling of the normalized correlation length and the normalized Binder cumulant are shown for the canonical Ising ferromagnet model in dimension three where hyperscaling holds, for the Ising ferromagnet in dimension five (so above the upper critical dimension) where hyperscaling breaks down, and then for Ising spin glass models in dimension three where the quenched interactions are random. For the Ising spin glasses there is a breakdown of the normalized Binder cumulant hyperscaling relation in the thermodynamic limit regime, with a return to size independent Binder cumulant values in the finite-size scaling regime around the critical region.

  2. Modeling the cumulative watershed effects of forest management strategies

    Science.gov (United States)

    R. R. Ziemer; J. Lewis; R. M. Rice; T. E. Lisle

    1991-01-01

    Abstract - There is increasing concern over the possibility of adverse cumulative watershed effects from intensive forest management. It is impractical to address many aspects of the problem experimentally because to do so would require studying large watersheds for 100 yr or more. One such aspect is the long-term effect of forest management strategies on erosion and...

  3. Development of cumulative distribution functions for dry bulb ...

    African Journals Online (AJOL)

    The probability density function (PDF) and cumulative distribution function (CDF) for eighteen locations in Nigeria were computed from long term hourly dry bulb temperature obtained from Nigerian Meteorological Services Agency, Oshodi, Nigeria for 1994-2008 or 1995-2009. Mathematical models were developed from the ...

  4. Analysis of sensory ratings data with cumulative link models

    DEFF Research Database (Denmark)

    Christensen, Rune Haubo Bojesen; Brockhoff, Per B.

    2013-01-01

    Examples of categorical rating scales include discrete preference, liking and hedonic rating scales. Data obtained on these scales are often analyzed with normal linear regression methods or with omnibus Pearson chi2 tests. In this paper we propose to use cumulative link models that allow for reg...

  5. Cumulative creep damage for unidirectional composites under step loading

    Science.gov (United States)

    Guedes, Rui Miranda

    2012-11-01

    The creep lifetime prediction of unidirectional composite materials under step loading, based on constant loading durability diagram, is analyzed for the two-step creep loading condition. For this purpose different nonlinear cumulative-damage laws are revisited and applied to predict creep lifetime. One possible approach to accounting for damage accumulation is provided by the continuum-damage mechanics (CDM). However, the CDM lifetime expression obtained for constant loading condition presents some drawbacks. Specifically, the upper stress range is not accommodated by CDM form. A modification of CDM is proposed, forcing the CDM to capture the short-term creep failure. It is proven that this modified CDM (MCDM) does not yield the same predictions as the Linear Cumulative-damage law (Miner's law). Predictions obtained from the nonlinear cumulative-damage laws are compared against synthetic lifetime generated by a micromechanical model that simulates unidirectional composites under two-step creep loading condition. Comparable deviations from Miner's law are obtained by the nonlinear cumulative-damage laws.

  6. The functional and anatomical dissection of somatosensory subpopulations using mouse genetics

    Directory of Open Access Journals (Sweden)

    Claire E Le Pichon

    2014-04-01

    Full Text Available The word somatosensation comes from joining the Greek word for body (soma with a word for perception (sensation. Somatosensory neurons comprise the largest sensory system in mammals and have nerve endings coursing throughout the skin, viscera, muscle, and bone. Their cell bodies reside in a chain of ganglia adjacent to the dorsal spinal cord (the dorsal root ganglia and at the base of the skull (the trigeminal ganglia. While the neuronal cell bodies are intermingled within the ganglia, the somatosensory system is in reality composed of numerous sub-systems, each specialized to detect distinct stimuli, such as temperature and touch. Historically, somatosensory neurons have been classified using a diverse host of anatomical and physiological parameters, such as the size of the cell body, degree of myelination, histological labeling with markers, specialization of the nerve endings, projection patterns in the spinal cord and brainstem, receptive tuning, and conduction velocity of their action potentials. While useful, the picture that emerged was one of heterogeneity, with many markers at least partially overlapping. More recently, by capitalizing on advances in molecular techniques, researchers have identified specific ion channels and sensory receptors expressed in subsets of sensory neurons. These studies have proved invaluable as they allow genetic access to small subsets of neurons for further molecular dissection. Data being generated from transgenic mice favor the model whereby an array of dedicated neurons is responsible for selectively encoding different modalities. Here we review the current knowledge of the different sensory neuron subtypes in the mouse, the markers used to study them, and the neurogenetic strategies used to define their anatomical projections and functional roles.

  7. MEG event-related desynchronization and synchronization deficits during basic somatosensory processing in individuals with ADHD

    Directory of Open Access Journals (Sweden)

    Wang Frank

    2008-02-01

    Full Text Available Abstract Background Attention-Deficit/Hyperactivity Disorder (ADHD is a prevalent, complex disorder which is characterized by symptoms of inattention, hyperactivity, and impulsivity. Convergent evidence from neurobiological studies of ADHD identifies dysfunction in fronto-striatal-cerebellar circuitry as the source of behavioural deficits. Recent studies have shown that regions governing basic sensory processing, such as the somatosensory cortex, show abnormalities in those with ADHD suggesting that these processes may also be compromised. Methods We used event-related magnetoencephalography (MEG to examine patterns of cortical rhythms in the primary (SI and secondary (SII somatosensory cortices in response to median nerve stimulation, in 9 adults with ADHD and 10 healthy controls. Stimuli were brief (0.2 ms non-painful electrical pulses presented to the median nerve in two counterbalanced conditions: unpredictable and predictable stimulus presentation. We measured changes in strength, synchronicity, and frequency of cortical rhythms. Results Healthy comparison group showed strong event-related desynchrony and synchrony in SI and SII. By contrast, those with ADHD showed significantly weaker event-related desynchrony and event-related synchrony in the alpha (8–12 Hz and beta (15–30 Hz bands, respectively. This was most striking during random presentation of median nerve stimulation. Adults with ADHD showed significantly shorter duration of beta rebound in both SI and SII except for when the onset of the stimulus event could be predicted. In this case, the rhythmicity of SI (but not SII in the ADHD group did not differ from that of controls. Conclusion Our findings suggest that somatosensory processing is altered in individuals with ADHD. MEG constitutes a promising approach to profiling patterns of neural activity during the processing of sensory input (e.g., detection of a tactile stimulus, stimulus predictability and facilitating our

  8. Movement-Related Sensorimotor High-Gamma Activity Mainly Represents Somatosensory Feedback

    Directory of Open Access Journals (Sweden)

    Seokyun Ryun

    2017-07-01

    Full Text Available Somatosensation plays pivotal roles in the everyday motor control of humans. During active movement, there exists a prominent high-gamma (HG >50 Hz power increase in the primary somatosensory cortex (S1, and this provides an important feature in relation to the decoding of movement in a brain-machine interface (BMI. However, one concern of BMI researchers is the inflation of the decoding performance due to the activation of somatosensory feedback, which is not elicited in patients who have lost their sensorimotor function. In fact, it is unclear as to how much the HG component activated in S1 contributes to the overall sensorimotor HG power during voluntary movement. With regard to other functional roles of HG in S1, recent findings have reported that these HG power levels increase before the onset of actual movement, which implies neural activation for top-down movement preparation or sensorimotor interaction, i.e., an efference copy. These results are promising for BMI applications but remain inconclusive. Here, we found using electrocorticography (ECoG from eight patients that HG activation in S1 is stronger and more informative than it is in the primary motor cortex (M1 regardless of the type of movement. We also demonstrate by means of electromyography (EMG that the onset timing of the HG power in S1 is later (49 ms than that of the actual movement. Interestingly, we show that the HG power fluctuations in S1 are closely related to subtle muscle contractions, even during the pre-movement period. These results suggest the following: (1 movement-related HG activity in S1 strongly affects the overall sensorimotor HG power, and (2 HG activity in S1 during voluntary movement mainly represents cortical neural processing for somatosensory feedback.

  9. Altered somatosensory barrel cortex refinement in the developing brain of Mecp2-null mice.

    Science.gov (United States)

    Moroto, M; Nishimura, A; Morimoto, M; Isoda, K; Morita, T; Yoshida, M; Morioka, S; Tozawa, T; Hasegawa, T; Chiyonobu, T; Yoshimoto, K; Hosoi, H

    2013-11-06

    Rett syndrome (RTT) is a neurodevelopmental disorder caused by mutations in the methyl-CpG binding protein 2 (MeCP2) gene. In previous studies, monoaminergic dysfunctions have been detected in patients with RTT and in a murine model of RTT, the Mecp2-null mouse. Therefore, the pathogenesis of RTT is thought to involve impairments in the monoaminergic systems. However, there have been limited data showing that the impairment of monoamines leads to early symptoms during development. We used histochemistry to study the somatosensory barrel cortex in the B6.129P2(C)-Mecp2(tm1.1Bird) mouse model of RTT. The barrel cortex is widely used to investigate neuronal development and its regulation by various neurotransmitters including 5-HT. 5-HT levels were measured by high performance liquid chromatography with electrochemical detection (HPLC/EC), and serotonin transporter (SERT) and 5-HT1B receptor mRNAs were measured in the somatosensory cortex, thalamus and striatum on postnatal days (P) 10, P20 and P40. Mecp2-null mice (Mecp2-/y) had significantly smaller barrel fields than age-matched wild-type controls (Mecp2+/y) on P10 and P40, but the topographic map was accurately formed. Levels of 5-HT, and SERT and 5-HT1B receptor mRNA expression in the somatosensory cortex did not differ significantly between the Mecp2-null and wild-type mice on P10. However, thalamic 5-HT was reduced in Mecp2-null mice. Our data indicate that a lack of MeCP2 may disturb the refinement of the barrel cortex in the early postnatal period. Our findings suggest that a decrease in thalamic 5-HT might be involved in this phenomenon. © 2013 Elsevier B.V. All rights reserved.

  10. Comparing development of synaptic proteins in rat visual, somatosensory, and frontal cortex

    Science.gov (United States)

    Pinto, Joshua G. A.; Jones, David G.; Murphy, Kathryn M.

    2013-01-01

    Two theories have influenced our understanding of cortical development: the integrated network theory, where synaptic development is coordinated across areas; and the cascade theory, where the cortex develops in a wave-like manner from sensory to non-sensory areas. These different views on cortical development raise challenges for current studies aimed at comparing detailed maturation of the connectome among cortical areas. We have taken a different approach to compare synaptic development in rat visual, somatosensory, and frontal cortex by measuring expression of pre-synaptic (synapsin and synaptophysin) proteins that regulate vesicle cycling, and post-synaptic density (PSD-95 and Gephyrin) proteins that anchor excitatory or inhibitory (E-I) receptors. We also compared development of the balances between the pairs of pre- or post-synaptic proteins, and the overall pre- to post-synaptic balance, to address functional maturation and emergence of the E-I balance. We found that development of the individual proteins and the post-synaptic index overlapped among the three cortical areas, but the pre-synaptic index matured later in frontal cortex. Finally, we applied a neuroinformatics approach using principal component analysis and found that three components captured development of the synaptic proteins. The first component accounted for 64% of the variance in protein expression and reflected total protein expression, which overlapped among the three cortical areas. The second component was gephyrin and the E-I balance, it emerged as sequential waves starting in somatosensory, then frontal, and finally visual cortex. The third component was the balance between pre- and post-synaptic proteins, and this followed a different developmental trajectory in somatosensory cortex. Together, these results give the most support to an integrated network of synaptic development, but also highlight more complex patterns of development that vary in timing and end point among the

  11. Laminar analysis of the slow wave activity in the somatosensory cortex of anesthetized rats.

    Science.gov (United States)

    Fiáth, Richárd; Kerekes, Bálint Péter; Wittner, Lucia; Tóth, Kinga; Beregszászi, Patrícia; Horváth, Domonkos; Ulbert, István

    2016-08-01

    Rhythmic slow waves characterize brain electrical activity during natural deep sleep and under anesthesia, reflecting the synchronous membrane potential fluctuations of neurons in the thalamocortical network. Strong evidence indicates that the neocortex plays an important role in the generation of slow wave activity (SWA), however, contributions of individual cortical layers to the SWA generation are still unclear. The anatomically correct laminar profiles of SWA were revealed under ketamine/xylazine anesthesia, with combined local field potential recordings, multiple-unit activity (MUA), current source density (CSD) and time-frequency analyses precisely co-registered with histology. The up-state related negative field potential wave showed the largest amplitude in layer IV, the CSD was largest in layers I and III, whereas MUA was maximal in layer V, suggesting spatially dissociated firing and synaptic/transmembrane processes in the rat somatosensory cortex. Up-state related firing could start in virtually any layers (III-VI) of the cortex, but were most frequently initiated in layer V. However, in a subset of experiments, layer IV was considerably active in initiating up-state related MUA even in the absence of somatosensory stimulation. Somatosensory stimulation further strengthened up-state initiation in layer IV. Our results confirm that cortical layer V firing may have a major contribution to the up-state generation of ketamine/xylazine-induced SWA, however, thalamic influence through the thalamorecipient layer IV can also play an initiating role, even in the absence of sensory stimulation. © 2016 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  12. Optogenetic conditioning of paradigm and pattern discrimination in the rat somatosensory system.

    Directory of Open Access Journals (Sweden)

    Kenta Abe

    Full Text Available The rodent whisker-barrel cortical system is a model for studying somatosensory discrimination at high spatiotemporal precision. Here, we applied optogenetics to produce somatosensory inputs in the whisker area using one of transgenic rat lines, W-TChR2V4, which expresses channelrhodopsin-2 (ChR2 in the mechanoreceptive nerve endings around whisker follicles. An awake W-TChR2V4 rat was head-fixed and irradiated by blue LED light on the whisker area with a paradigm conditioned with a reward. The Go task was designed so the rat is allowed to receive a reward, when it licked the nozzle within 5 s after photostimulation. The No-go task was designed so as the rat has to withhold licking for at least 5 s to obtain a reward after photostimulation. The Go-task conditioning was established within 1 hr of training with a reduction in the reaction time and increase of the success rate. To investigate the relationship between the spatiotemporal pattern of sensory inputs and the behavioral output, we designed a multi-optical fiber system that irradiates the whisker area at 9 spots in a 3×3 matrix. Although the Go-task conditioning was established using synchronous irradiation of 9 spots, the success rate was decreased with an increase of the reaction time for the asynchronous irradiation. After conditioning to the Go task, the rat responded to the blue LED flash irradiated on the barrel cortex, where many neurons also express ChR2, or photostimulation of the contralateral whisker area with a similar reaction time and success rate. Synchronous activation of the peripheral mechanoreceptive nerves is suggested to drive a neural circuit in the somatosensory cortex that efficiently couples with the decision. Our optogenetic system would enable the precise evaluation of the psychophysical values, such as the reaction time and success rate, to gain some insight into the brain mechanisms underlying conditioned behaviors.

  13. Optogenetic conditioning of paradigm and pattern discrimination in the rat somatosensory system.

    Science.gov (United States)

    Abe, Kenta; Yawo, Hiromu

    2017-01-01

    The rodent whisker-barrel cortical system is a model for studying somatosensory discrimination at high spatiotemporal precision. Here, we applied optogenetics to produce somatosensory inputs in the whisker area using one of transgenic rat lines, W-TChR2V4, which expresses channelrhodopsin-2 (ChR2) in the mechanoreceptive nerve endings around whisker follicles. An awake W-TChR2V4 rat was head-fixed and irradiated by blue LED light on the whisker area with a paradigm conditioned with a reward. The Go task was designed so the rat is allowed to receive a reward, when it licked the nozzle within 5 s after photostimulation. The No-go task was designed so as the rat has to withhold licking for at least 5 s to obtain a reward after photostimulation. The Go-task conditioning was established within 1 hr of training with a reduction in the reaction time and increase of the success rate. To investigate the relationship between the spatiotemporal pattern of sensory inputs and the behavioral output, we designed a multi-optical fiber system that irradiates the whisker area at 9 spots in a 3×3 matrix. Although the Go-task conditioning was established using synchronous irradiation of 9 spots, the success rate was decreased with an increase of the reaction time for the asynchronous irradiation. After conditioning to the Go task, the rat responded to the blue LED flash irradiated on the barrel cortex, where many neurons also express ChR2, or photostimulation of the contralateral whisker area with a similar reaction time and success rate. Synchronous activation of the peripheral mechanoreceptive nerves is suggested to drive a neural circuit in the somatosensory cortex that efficiently couples with the decision. Our optogenetic system would enable the precise evaluation of the psychophysical values, such as the reaction time and success rate, to gain some insight into the brain mechanisms underlying conditioned behaviors.

  14. Prenatal nicotine exposure evokes alterations of cell structure in hippocampus and somatosensory cortex.

    Science.gov (United States)

    Roy, Tara Sankar; Seidler, Frederic J; Slotkin, Theodore A

    2002-01-01

    Offspring of women who smoke during pregnancy show behavioral abnormalities, including increased incidence of attentional deficit, learning disabilities, and cognitive dysfunction. Animal models indicate that nicotine elicits changes in neural cell replication and differentiation, leading to deficits in synaptic neurochemistry and behavioral performance, many of which first emerge at adolescence. We evaluated cellular morphology and regional architecture in the juvenile and adolescent hippocampus and the somatosensory cortex in rats exposed to nicotine prenatally. Pregnant rats were given nicotine throughout gestation via minipump infusion of 2 mg/kg/day, a regimen that elicits nicotine plasma levels comparable with those found in smokers. On postnatal days 21 and 30, brains were perfusion-fixed, coronal slices were taken between the anterior commissure and median eminence, and the morphology of the dorsal hippocampus and somatosensory cortex was characterized. In the hippocampal CA3 region and dentate gyrus, we found a substantial decrease in cell size, with corresponding decrements in cell layer thickness, and increments in cell packing density. Smaller, transient changes were seen in CA1. In layer 5 of the somatosensory cortex, although there was no significant decrement in the average cell size, there was a reduction in the proportion of medium-sized pyramidal neurons, and an increase in the proportion of smaller, nonpyramidal cells. All regions showed elevated numbers of glia. Taken together with previous work on neurochemical and functional defects, these data demonstrate that prenatal nicotine exposure compromises neuronal maturation, leading to long-lasting alterations in the structure of key brain regions involved in cognition, learning, and memory.

  15. Comparing development of synaptic proteins in rat visual, somatosensory, and frontal cortex.

    Science.gov (United States)

    Pinto, Joshua G A; Jones, David G; Murphy, Kathryn M

    2013-01-01

    Two theories have influenced our understanding of cortical development: the integrated network theory, where synaptic development is coordinated across areas; and the cascade theory, where the cortex develops in a wave-like manner from sensory to non-sensory areas. These different views on cortical development raise challenges for current studies aimed at comparing detailed maturation of the connectome among cortical areas. We have taken a different approach to compare synaptic development in rat visual, somatosensory, and frontal cortex by measuring expression of pre-synaptic (synapsin and synaptophysin) proteins that regulate vesicle cycling, and post-synaptic density (PSD-95 and Gephyrin) proteins that anchor excitatory or inhibitory (E-I) receptors. We also compared development of the balances between the pairs of pre- or post-synaptic proteins, and the overall pre- to post-synaptic balance, to address functional maturation and emergence of the E-I balance. We found that development of the individual proteins and the post-synaptic index overlapped among the three cortical areas, but the pre-synaptic index matured later in frontal cortex. Finally, we applied a neuroinformatics approach using principal component analysis and found that three components captured development of the synaptic proteins. The first component accounted for 64% of the variance in protein expression and reflected total protein expression, which overlapped among the three cortical areas. The second component was gephyrin and the E-I balance, it emerged as sequential waves starting in somatosensory, then frontal, and finally visual cortex. The third component was the balance between pre- and post-synaptic proteins, and this followed a different developmental trajectory in somatosensory cortex. Together, these results give the most support to an integrated network of synaptic development, but also highlight more complex patterns of development that vary in timing and end point among the

  16. Within, but not between hands interactions in vibrotactile detection thresholds reflect somatosensory receptive field organization

    Directory of Open Access Journals (Sweden)

    Luigi eTamè

    2014-02-01

    Full Text Available Detection of a tactile stimulus on one finger is impaired when a concurrent stimulus (masker is presented on an additional finger of the same or the opposite hand. This phenomenon is known to be finger-specific at the within-hand level. However, whether this specificity is also maintained at the between-hand level is not known. In four experiments, we addressed this issue by combining a Bayesian adaptive staircase procedure (QUEST with a two-interval forced choice (2IFC design in order to establish threshold for detecting 200ms, 100Hz sinusoidal vibrations applied to the index or little fingertip of either hand (targets. We systematically varied the masker finger (index, middle, ring, or little finger of either hand, while controlling the spatial location of the target and masker stimuli. Detection thresholds varied consistently as a function of the masker finger when the latter was on the same hand (Experiments 1 and 2, but not when on different hands (Experiments 3 and 4. Within the hand, detection thresholds increased for masker fingers closest to the target finger (i.e., middle>ring when the target was index. Between the hands, detection thresholds were higher only when the masker was present on any finger as compared to when the target was presented in isolation. The within hand effect of masker finger is consistent with the segregation of different fingers at the early stages of somatosensory processing, from the periphery to the primary somatosensory cortex (SI. We propose that detection is finger-specific and reflects the organisation of somatosensory receptive fields in SI within, but not between the hands.

  17. Somatosensory evoked field in response to visuotactile stimulation in 3- to 4-year-old children

    Directory of Open Access Journals (Sweden)

    Gerard Bastiaan Remijn

    2014-03-01

    Full Text Available A child-customsized magnetoencephalography (MEG system was used to investigate somatosensory evoked field (SEF in 3- to 4-year-old children. Three stimulus conditions were used in which the children received tactile-only stimulation to their left index finger, or visuotactile stimulation. In the two visuotactile conditions the children received tactile stimulation to their finger while they watched a video of tactile stimulation applied either to someone else’s finger (the finger-touch condition, or to someone else’s toe (the toe-touch condition. The latencies and source strengths of equivalent current dipoles (ECD over contralateral (right somatosensory cortex were analyzed. In the preschoolers who provided valid ECDs, the stimulus conditions induced an early-latency ECD occurring in between 60-68 ms mainly with an anterior direction. We further identified a middle-latency ECD in between 97-104 ms, which predominantly had a posterior direction. Finally, initial evidence was found for a late-latency ECD at about 139-151 ms again more often with an anterior direction. Differences were found in the source strengths of the middle-latency ECDs among the stimulus conditions. For the paired comparisons that could be formed, ECD source strength was more pronounced in the finger-touch condition than in the tactile-only and the toe-touch condition. Although more research is necessary to expand the data set, this suggests that visual information modulated preschool SEF. The finding that ECD source strength was higher when seen and felt touch occurred to the same body part, as compared to a different body part, might further indicate that connectivity between visual and tactile information is indexed in preschool somatosensory cortical activity, already in a somatotopic way.

  18. Asymmetric Functional Connectivity of the Contra- and Ipsilateral Secondary Somatosensory Cortex during Tactile Object Recognition

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    Yinghua Yu

    2018-01-01

    Full Text Available In the somatosensory system, it is well known that the bilateral secondary somatosensory cortex (SII receives projections from the unilateral primary somatosensory cortex (SI, and the SII, in turn, sends feedback projections to SI. Most neuroimaging studies have clearly shown bilateral SII activation using only unilateral stimulation for both anatomical and functional connectivity across SII subregions. However, no study has unveiled differences in the functional connectivity of the contra- and ipsilateral SII network that relates to frontoparietal areas during tactile object recognition. Therefore, we used event-related functional magnetic resonance imaging (fMRI and a delayed match-to-sample (DMS task to investigate the contributions of bilateral SII during tactile object recognition. In the fMRI experiment, 14 healthy subjects were presented with tactile angle stimuli on their right index finger and asked to encode three sample stimuli during the encoding phase and one test stimulus during the recognition phase. Then, the subjects indicated whether the angle of test stimulus was presented during the encoding phase. The results showed that contralateral (left SII activity was greater than ipsilateral (right SII activity during the encoding phase, but there was no difference during the recognition phase. A subsequent psycho-physiological interaction (PPI analysis revealed distinct connectivity from the contra- and ipsilateral SII to other regions. The left SII functionally connected to the left SI and right primary and premotor cortex, while the right SII functionally connected to the left posterior parietal cortex (PPC. Our findings suggest that in situations involving unilateral tactile object recognition, contra- and ipsilateral SII will induce an asymmetrical functional connectivity to other brain areas, which may occur by the hand contralateral effect of SII.

  19. Asymmetric Functional Connectivity of the Contra- and Ipsilateral Secondary Somatosensory Cortex during Tactile Object Recognition.

    Science.gov (United States)

    Yu, Yinghua; Yang, Jiajia; Ejima, Yoshimichi; Fukuyama, Hidenao; Wu, Jinglong

    2017-01-01

    In the somatosensory system, it is well known that the bilateral secondary somatosensory cortex (SII) receives projections from the unilateral primary somatosensory cortex (SI), and the SII, in turn, sends feedback projections to SI. Most neuroimaging studies have clearly shown bilateral SII activation using only unilateral stimulation for both anatomical and functional connectivity across SII subregions. However, no study has unveiled differences in the functional connectivity of the contra- and ipsilateral SII network that relates to frontoparietal areas during tactile object recognition. Therefore, we used event-related functional magnetic resonance imaging (fMRI) and a delayed match-to-sample (DMS) task to investigate the contributions of bilateral SII during tactile object recognition. In the fMRI experiment, 14 healthy subjects were presented with tactile angle stimuli on their right index finger and asked to encode three sample stimuli during the encoding phase and one test stimulus during the recognition phase. Then, the subjects indicated whether the angle of test stimulus was presented during the encoding phase. The results showed that contralateral (left) SII activity was greater than ipsilateral (right) SII activity during the encoding phase, but there was no difference during the recognition phase. A subsequent psycho-physiological interaction (PPI) analysis revealed distinct connectivity from the contra- and ipsilateral SII to other regions. The left SII functionally connected to the left SI and right primary and premotor cortex, while the right SII functionally connected to the left posterior parietal cortex (PPC). Our findings suggest that in situations involving unilateral tactile object recognition, contra- and ipsilateral SII will induce an asymmetrical functional connectivity to other brain areas, which may occur by the hand contralateral effect of SII.

  20. Cortical somatosensory reorganization in children with spastic cerebral palsy: a multimodal neuroimaging study

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    CHRISTOS ePAPADELIS

    2014-09-01

    Full Text Available Although cerebral palsy (CP is among the most common causes of physical disability in early childhood, we know little about the functional and structural changes of this disorder in the developing brain. Here, we investigated with three different neuroimaging modalities (magnetoencephalography (MEG, diffusion tension imaging (DTI, and resting state fMRI whether spastic CP is associated with functional and anatomical abnormalities in the sensorimotor network. Ten children participated in the study: four with diplegic CP (DCP, three with hemiplegic CP (HCP, and three typically-developing (TD children. Somatosensory evoked fields (SEFs were recorded in response to pneumatic stimuli applied to digits D1, D3, and D5 of both hands. Several parameters of water diffusion were calculated from DTI between the thalamus and the precentral and postcentral gyri in both hemispheres. The sensorimotor resting state networks (RSNs were examined by using an independent component analysis method. Tactile stimulation of the fingers elicited the first prominent cortical response at ~50 ms, in all except one child, localized over the primary somatosensory cortex (S1. In five CP children, abnormal somatotopic organization was observed in the affected (or more affected hemisphere. Euclidean distances were markedly different between the two hemispheres in the HCP children, and between DCP and TD children for both hemispheres. DTI analysis revealed decreased fractional anisotropy and increased apparent diffusion coefficient for the thalamocortical pathways in the more affected compared to less affected hemisphere in CP children. Rs-fMRI results indicated absent and/or abnormal sensorimotor RSNs for children with HCP and DCP consistent with the severity and location of their lesions. Our findings suggest an abnormal somatosensory processing mechanism in the sensorimotor network of children with CP possibly as a result of diminished thalamocortical projections.

  1. Increased excitability of somatosensory cortex in aged humans is associated with impaired tactile acuity.

    Science.gov (United States)

    Lenz, Melanie; Tegenthoff, Martin; Kohlhaas, Karsten; Stude, Philipp; Höffken, Oliver; Gatica Tossi, Mario A; Kalisch, Tobias; Kowalewski, Rebecca; Dinse, Hubert R

    2012-02-01

    Aging affects all levels of neural processing, including changes of intracortical inhibition and cortical excitability. Paired-pulse stimulation, the application of two stimuli in close succession, is a useful tool to investigate cortical excitability in humans. The paired-pulse behavior is characterized by the second response being significantly suppressed at short stimulus onset asynchronies. While in rat somatosensory cortex, intracortical inhibition has been demonstrated to decline with increasing age, data from human motor cortex of elderly subjects are controversial and there are no data for the human somatosensory cortex (SI). Moreover, behavioral implications of age-related changes of cortical excitability remain elusive. We therefore assessed SI excitability by combining paired-pulse median nerve stimulation with recording somatosensory evoked potentials in 138 healthy subjects aged 17-86 years. We found that paired-pulse suppression was characterized by substantial interindividual variability, but declined significantly with age, confirming reduced intracortical inhibition in elderly subjects. To link the age-related increase of cortical excitability to perceptual changes, we measured tactile two-point discrimination in a subsample of 26 aged participants who showed either low or high paired-pulse suppression. We found that tactile performance was particularly impaired in subjects showing markedly enhanced cortical excitability. Our data demonstrate that paired-pulse suppression of human SI is significantly reduced in older adults, and that age-related enhancement of cortical excitability correlates with degradation of tactile perception. These findings indicate that cortical excitability constitutes an important mechanism that links age-related neurophysiological changes to behavioral alterations in humans.

  2. Brownian Optogenetic-Noise-Photostimulation on the Brain Amplifies Somatosensory-Evoked Field Potentials

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    Nayeli Huidobro

    2017-08-01

    Full Text Available Stochastic resonance (SR is an inherent and counter-intuitive mechanism of signal-to-noise ratio (SNR facilitation in biological systems associated with the application of an intermediate level of noise. As a first step to investigate in detail this phenomenon in the somatosensory system, here we examined whether the direct application of noisy light on pyramidal neurons from the mouse-barrel cortex expressing a light-gated channel channelrhodopsin-2 (ChR2 can produce facilitation in somatosensory evoked field potentials. Using anesthetized Thy1-ChR2-YFP transgenic mice, and a new neural technology, that we called Brownian optogenetic-noise-photostimulation (BONP, we provide evidence for how BONP directly applied on the barrel cortex modulates the SNR in the amplitude of whisker-evoked field potentials (whisker-EFP. In all transgenic mice, we found that the SNR in the amplitude of whisker-EFP (at 30% of the maximal whisker-EFP exhibited an inverted U-like shape as a function of the BONP level. As a control, we also applied the same experimental paradigm, but in wild-type mice, as expected, we did not find any facilitation effects. Our results show that the application of an intermediate intensity of BONP on the barrel cortex of ChR2 transgenic mice amplifies the SNR of somatosensory whisker-EFPs. This result may be relevant to explain the improvements found in sensory detection in humans produced by the application of transcranial-random-noise-stimulation (tRNS on the scalp.

  3. Impaired verbal memory in Parkinson disease: relationship to prefrontal dysfunction and somatosensory discrimination

    Directory of Open Access Journals (Sweden)

    Weniger Dorothea

    2009-12-01

    Full Text Available Abstract Objective To study the neurocognitive profile and its relationship to prefrontal dysfunction in non-demented Parkinson's disease (PD with deficient haptic perception. Methods Twelve right-handed patients with PD and 12 healthy control subjects underwent thorough neuropsychological testing including Rey complex figure, Rey auditory verbal and figural learning test, figural and verbal fluency, and Stroop test. Test scores reflecting significant differences between patients and healthy subjects were correlated with the individual expression coefficients of one principal component, obtained in a principal component analysis of an oxygen-15-labeled water PET study exploring somatosensory discrimination that differentiated between the two groups and involved prefrontal cortices. Results We found significantly decreased total scores for the verbal learning trials and verbal delayed free recall in PD patients compared with normal volunteers. Further analysis of these parameters using Spearman's ranking correlation showed a significantly negative correlation of deficient verbal recall with expression coefficients of the principal component whose image showed a subcortical-cortical network, including right dorsolateral-prefrontal cortex, in PD patients. Conclusion PD patients with disrupted right dorsolateral prefrontal cortex function and associated diminished somatosensory discrimination are impaired also in verbal memory functions. A negative correlation between delayed verbal free recall and PET activation in a network including the prefrontal cortices suggests that verbal cues and accordingly declarative memory processes may be operative in PD during activities that demand sustained attention such as somatosensory discrimination. Verbal cues may be compensatory in nature and help to non-specifically enhance focused attention in the presence of a functionally disrupted prefrontal cortex.

  4. Laminar microvascular transit time distribution in the mouse somatosensory cortex revealed by Dynamic Contrast Optical Coherence Tomography.

    Science.gov (United States)

    Merkle, Conrad W; Srinivasan, Vivek J

    2016-01-15

    The transit time distribution of blood through the cerebral microvasculature both constrains oxygen delivery and governs the kinetics of neuroimaging signals such as blood-oxygen-level-dependent functional Magnetic Resonance Imaging (BOLD fMRI). However, in spite of its importance, capillary transit time distribution has been challenging to quantify comprehensively and efficiently at the microscopic level. Here, we introduce a method, called Dynamic Contrast Optical Coherence Tomography (DyC-OCT), based on dynamic cross-sectional OCT imaging of an intravascular tracer as it passes through the field-of-view. Quantitative transit time metrics are derived from temporal analysis of the dynamic scattering signal, closely related to tracer concentration. Since DyC-OCT does not require calibration of the optical focus, quantitative accuracy is achieved even deep in highly scattering brain tissue where the focal spot degrades. After direct validation of DyC-OCT against dilution curves measured using a fluorescent plasma label in surface pial vessels, we used DyC-OCT to investigate the transit time distribution in microvasculature across the entire depth of the mouse somatosensory cortex. Laminar trends were identified, with earlier transit times and less heterogeneity in the middle cortical layers. The early transit times in the middle cortical layers may explain, at least in part, the early BOLD fMRI onset times observed in these layers. The layer-dependencies in heterogeneity may help explain how a single vascular supply manages to deliver oxygen to individual cortical layers with diverse metabolic needs. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Cerebral haemodynamic response to somatosensory stimulation in near-term fetal sheep.

    Science.gov (United States)

    Nakamura, S; Walker, D W; Wong, F Y

    2017-02-15

    Cerebral haemodynamic response to neural stimulation has been extensively investigated in animal and clinical studies, in both adult and paediatric populations, but little is known about cerebral haemodynamic functional response in the fetal brain. The present study describes the cerebral haemodynamic response measured by near-infrared spectroscopy to somatosensory stimulation in fetal sheep. The cerebral haemodynamic response in the fetal sheep brain changes from a positive (increase in oxyhaemoglobin (oxyHb)) response pattern to a negative or biphasic response pattern when the duration of somatosensory stimulation is increased, probably due to cerebral vasoconstriction with prolonged stimulations. In contrast to adult studies, we have found that changes in fetal cerebral blood flow and oxyHb are positively increased in response to somatosensory stimulation during hypercapnia. We propose this is related to reduced vascular resistance and recruitment of cerebral vasculature in the fetal brain during hypercapnia. Functional hyperaemia induced by a localised increase in neuronal activity has been suggested to occur in the fetal brain owing to a positive blood oxygen level-dependent (BOLD) signal recorded by functional magnetic resonance imaging following acoustic stimulation. To study the effect of somatosensory input on local cerebral perfusion we used near-infrared spectroscopy (NIRS) in anaesthetised, partially exteriorised fetal sheep where the median nerve was stimulated with trains of pulses (2 ms, 3.3 Hz) for durations of 1.8, 4.8 and 7.8 s. Signal averaging of cerebral NIRS responses to 20 stimulus trains repeated every 60 s revealed that a short duration of stimulation (1.8 s) increased oxyhaemoglobin in the contralateral cortex consistent with a positive functional response, whereas longer durations of stimulation (4.8, 7.8 s) produced more variable oxyhaemoglobin responses including positive, negative and biphasic patterns of change. Mean arterial

  6. [Somatosensory focal seizures as an onset form in adult Moyamoya syndrome].

    Science.gov (United States)

    Molina, C; Alvarez Sabín, J; Bosch, J; Codina Puiggrós, A

    1995-01-01

    Moya-Moya disease is a chronic infrequent vasculopathy. Occasionally such abnormalities are found in association with one of many conditions, in these cases the angiographic abnormality should be termed Moya-Moya syndrome rather than Moya-Moya disease. Although in children the usual manifestations are ischemic events and seizures. This clinical presentation is infrequent in adults. We present a 42-years-old man with a 1-month history of recurrent right sided partial somatosensorial seizures, later he presented a left parietal infarction, the angiographic findings were compatible with moyamoya syndrome.

  7. ISPMER: Integrated system for combined PET, MRI, and electrophysiological recording in somatosensory studies in rats

    Energy Technology Data Exchange (ETDEWEB)

    Shih, Y.-Y. [Institute of Biomedical Engineering, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, Taiwan (China); Chen, Y.-Y. [Department of Electrical and Control Engineering, National Chiao-Tung University, Hsinchu, Taiwan (China); Chen, J.-C. [Faculty of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan (China); Department of Education and Research, Taipei City Hospital, Taipei, Taiwan (China); Chang Chen [Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan (China); Jaw, F.-S. [Institute of Biomedical Engineering, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, Taiwan (China)], E-mail: jaw@ha.mc.ntu.edu.tw

    2007-10-01

    The present study developed an integrated system for use in combined PET, MRI, and electrophysiological recording in somatosensory studies in rats, called ISPMER. A stereotaxic frame was designed for animal positioning that could be used in all three measurement modalities, and its dimensions complied with the gold standard of the Paxinos and Watson rat brain atlas. A graphical user interface was developed for analyzing the data using several signal processing algorithms. This integrated system provides a novel interface for the recording and processing of three-dimensional neuronal signals in three modalities.

  8. Cerebral haemodynamic response to somatosensory stimulation in near‐term fetal sheep

    Science.gov (United States)

    Nakamura, S.; Walker, D. W.

    2016-01-01

    Key points Cerebral haemodynamic response to neural stimulation has been extensively investigated in animal and clinical studies, in both adult and paediatric populations, but little is known about cerebral haemodynamic functional response in the fetal brain.The present study describes the cerebral haemodynamic response measured by near‐infrared spectroscopy to somatosensory stimulation in fetal sheep.The cerebral haemodynamic response in the fetal sheep brain changes from a positive (increase in oxyhaemoglobin (oxyHb)) response pattern to a negative or biphasic response pattern when the duration of somatosensory stimulation is increased, probably due to cerebral vasoconstriction with prolonged stimulations.In contrast to adult studies, we have found that changes in fetal cerebral blood flow and oxyHb are positively increased in response to somatosensory stimulation during hypercapnia. We propose this is related to reduced vascular resistance and recruitment of cerebral vasculature in the fetal brain during hypercapnia. Abstract Functional hyperaemia induced by a localised increase in neuronal activity has been suggested to occur in the fetal brain owing to a positive blood oxygen level‐dependent (BOLD) signal recorded by functional magnetic resonance imaging following acoustic stimulation. To study the effect of somatosensory input on local cerebral perfusion we used near‐infrared spectroscopy (NIRS) in anaesthetised, partially exteriorised fetal sheep where the median nerve was stimulated with trains of pulses (2 ms, 3.3 Hz) for durations of 1.8, 4.8 and 7.8 s. Signal averaging of cerebral NIRS responses to 20 stimulus trains repeated every 60 s revealed that a short duration of stimulation (1.8 s) increased oxyhaemoglobin in the contralateral cortex consistent with a positive functional response, whereas longer durations of stimulation (4.8, 7.8 s) produced more variable oxyhaemoglobin responses including positive, negative and biphasic patterns of

  9. Functional response of cerebral blood flow induced by somatosensory stimulation in rats with subarachnoid hemorrhage

    Science.gov (United States)

    Li, Zhiguo; Huang, Qin; Liu, Peng; Li, Pengcheng; Ma, Lianting; Lu, Jinling

    2015-09-01

    Subarachnoid hemorrhage (SAH) is often accompanied by cerebral vasospasm (CVS), which is the phenomenon of narrowing of large cerebral arteries, and then can produce delayed ischemic neurological deficit (DIND) such as lateralized sensory dysfunction. CVS was regarded as a major contributor to DIND in patients with SAH. However, therapy for preventing vasospasm after SAH to improve the outcomes may not work all the time. It is important to find answers to the relationship between CVS and DIND after SAH. How local cerebral blood flow (CBF) is regulated during functional activation after SAH still remains poorly understood, whereas, the regulation of CBF may play an important role in weakening the impact of CVS on cortex function. Therefore, it is worthwhile to evaluate the functional response of CBF in the activated cortex in an SAH animal model. Most evaluation of the effect of SAH is presently carried out by neurological behavioral scales. The functional imaging of cortical activation during sensory stimulation may help to reflect the function of the somatosensory cortex more locally than the behavioral scales do. We investigated the functional response of CBF in the somatosensory cortex induced by an electrical stimulation to contralateral forepaw via laser speckle imaging in a rat SAH model. Nineteen Sprague-Dawley rats from two groups (control group, n=10 and SAH group, n=9) were studied. SAH was induced in rats by double injection of autologous blood into the cisterna magna after CSF aspiration. The same surgical procedure was applied in the control group without CSF aspiration or blood injection. Significant CVS was found in the SAH group. Meanwhile, we observed a delayed peak of CBF response in rats with SAH compared with those in the control group, whereas no significant difference was found in magnitude, duration, and areas under curve of relative CBF changes between the two groups. The results suggest that the regulation function of local CBF during

  10. Visual cortical somatosensory and brainstem auditory evoked potentials following incidental irradiation of the rhombencephalon

    Energy Technology Data Exchange (ETDEWEB)

    Nightingale, S. (Royal Victoria Infirmary, Newcastle upon Tyne (UK)); Schofield, I.S.; Dawes, P.J.D.K. (Newcastle upon Tyne Univ. (UK). Newcastle General Hospital)

    1984-01-01

    Visual, cortical somatosensory and brainstem auditory evoked potentials were recorded before incidental irradiation of the rhombencephalon during radiotherapy in and around the middle ear, and at 11 weeks and eight months after completion of treatment. No patient experienced neurological symptoms during this period. No consistent changes in evoked potentials were found. The failure to demonstrate subclinical radiation-induced demyelination suggests either that the syndrome of early-delayed radiation rhombencephalopathy occurs in an idiosyncratic manner, or that any subclinical lesions are not detectable by serial evoked potential recordings.

  11. Visual cortical somatosensory and brainstem auditory evoked potentials following incidental irradiation of the rhombencephalon

    International Nuclear Information System (INIS)

    Nightingale, S.; Schofield, I.S.; Dawes, P.J.D.K.

    1984-01-01

    Visual, cortical somatosensory and brainstem auditory evoked potentials were recorded before incidental irradiation of the rhombencephalon during radiotherapy in and around the middle ear, and at 11 weeks and eight months after completion of treatment. No patient experienced neurological symptoms during this period. No consistent changes in evoked potentials were found. The failure to demonstrate subclinical radiation-induced demyelination suggests either that the syndrome of early-delayed radiation rhombencephalopathy occurs in an idiosyncratic manner, or that any subclinical lesions are not detectable by serial evoked potential recordings. (author)

  12. Effect of cumulative exposure on nasal response to ozone

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, R.F.; Hotchkiss, J.A.; Chang, I.Y.; Scott, B.R.; Harkema, J.R. (Inhalation Toxicology Research Institute, Albuquerque, NM (United States))

    1993-03-01

    To assess the potential health risks associated with exposure to low levels of ozone, it is essential to know if the ozone-induced responses are dependent on cumulative exposures or on the peak concentrations. To answer this question female F344/N rats, 11-13 weeks of age, were exposed to a matrix of equal concentration x time values that included exposures to 0, 0.12, 0.24, and 0.48 ppm ozone for 3, 6, 12, or 24 hr. the response of the nasal epithelium was measured as induced DNA synthesis determined by the uptake of bromodeoxyuridine (a thymidine analog) into epithelial cells lining the nasal anterior maxilloturbinates. No increased DNA synthesis was observed in rats exposed to 0.12 ppm ozone for any of the time periods. For exposures higher than 0.12 ppm ozone, the response of the nasal epithelium was similar for equal cumulative exposures. The responses, however, were not linearly related to the cumulative (concentration x time) exposures. It appeared that some mitigating factor was present which decreased the responses at the higher cumulative exposures. No frank toxicity or cellular necrosis was observed, indicating that sublethal cell damage was sufficient to induce DNA synthesis. A simple mathematical model was developed to describe the relationship between ozone exposure and the induction of DNA synthesis in the nasal epithelium. The model predicted that the threshold concentration of ozone for inducing DNA synthesis in the nasal epithelium was 0.1 +/- 0.1 ppm. For one measure of ozone toxicity (induced DNA synthesis) at a sensitive site in the respiratory tract (maxilloturbinates), the effects of ozone were dependent on cumulative exposures at concentrations > 0.12 ppm and within the time and concentration ranges used in this study.

  13. The challenges and opportunities in cumulative effects assessment

    International Nuclear Information System (INIS)

    Foley, Melissa M.; Mease, Lindley A.; Martone, Rebecca G.; Prahler, Erin E.; Morrison, Tiffany H.; Murray, Cathryn Clarke; Wojcik, Deborah

    2017-01-01

    The cumulative effects of increasing human use of the ocean and coastal zone have contributed to a rapid decline in ocean and coastal resources. As a result, scientists are investigating how multiple, overlapping stressors accumulate in the environment and impact ecosystems. These investigations are the foundation for the development of new tools that account for and predict cumulative effects in order to more adequately prevent or mitigate negative effects. Despite scientific advances, legal requirements, and management guidance, those who conduct assessments—including resource managers, agency staff, and consultants—continue to struggle to thoroughly evaluate cumulative effects, particularly as part of the environmental assessment process. Even though 45 years have passed since the United States National Environmental Policy Act was enacted, which set a precedent for environmental assessment around the world, defining impacts, baseline, scale, and significance are still major challenges associated with assessing cumulative effects. In addition, we know little about how practitioners tackle these challenges or how assessment aligns with current scientific recommendations. To shed more light on these challenges and gaps, we undertook a comparative study on how cumulative effects assessment (CEA) is conducted by practitioners operating under some of the most well-developed environmental laws around the globe: California, USA; British Columbia, Canada; Queensland, Australia; and New Zealand. We found that practitioners used a broad and varied definition of impact for CEA, which led to differences in how baseline, scale, and significance were determined. We also found that practice and science are not closely aligned and, as such, we highlight opportunities for managers, policy makers, practitioners, and scientists to improve environmental assessment.

  14. The challenges and opportunities in cumulative effects assessment

    Science.gov (United States)

    Foley, Melissa M.; Mease, Lindley A; Martone, Rebecca G; Prahler, Erin E; Morrison, Tiffany H; Clarke Murray, Cathryn; Wojcik, Deborah

    2016-01-01

    The cumulative effects of increasing human use of the ocean and coastal zone have contributed to a rapid decline in ocean and coastal resources. As a result, scientists are investigating how multiple, overlapping stressors accumulate in the environment and impact ecosystems. These investigations are the foundation for the development of new tools that account for and predict cumulative effects in order to more adequately prevent or mitigate negative effects. Despite scientific advances, legal requirements, and management guidance, those who conduct assessments—including resource managers, agency staff, and consultants—continue to struggle to thoroughly evaluate cumulative effects, particularly as part of the environmental assessment process. Even though 45 years have passed since the United States National Environmental Policy Act was enacted, which set a precedent for environmental assessment around the world, defining impacts, baseline, scale, and significance are still major challenges associated with assessing cumulative effects. In addition, we know little about how practitioners tackle these challenges or how assessment aligns with current scientific recommendations. To shed more light on these challenges and gaps, we undertook a comparative study on how cumulative effects assessment (CEA) is conducted by practitioners operating under some of the most well-developed environmental laws around the globe: California, USA; British Columbia, Canada; Queensland, Australia; and New Zealand. We found that practitioners used a broad and varied definition of impact for CEA, which led to differences in how baseline, scale, and significance were determined. We also found that practice and science are not closely aligned and, as such, we highlight opportunities for managers, policy makers, practitioners, and scientists to improve environmental assessment.

  15. How the vestibular system interacts with somatosensory perception: a sham-controlled study with galvanic vestibular stimulation.

    Science.gov (United States)

    Ferrè, Elisa R; Day, Brian L; Bottini, Gabriella; Haggard, Patrick

    2013-08-29

    The vestibular system has widespread interactions with other sensory modalities. Here we investigate whether vestibular stimulation modulates somatosensory function, by assessing the ability to detect faint tactile stimuli to the fingertips of the left and right hand with or without galvanic vestibular stimulation (GVS). We found that left anodal and right cathodal GVS, significantly enhanced sensitivity to mild shocks on either hand, without affecting response bias. There was no such effect with either right anodal and left cathodal GVS or sham stimulation. Further, the enhancement of somatosensory sensitivity following GVS does not strongly depend on the duration of GVS, or the interval between GVS and tactile stimulation. Vestibular inputs reach the somatosensory cortex, increasing the sensitivity of perceptual circuitry. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  16. Neurophysiological changes in the afferent somatosensory system indices in the case of vertebrogenic spine pathology in miners.

    Science.gov (United States)

    Battakova, Sharbanu; Shraimanov, Bekkair

    2013-04-01

    The aim of the paper was to prove that job conditions impact the state of the afferent part of the somatosensory system in miners. Data analysis of the electrophysiological examination of the syndrome in 148 patients, aged from 28 to 55 years, with a mild, moderate and severe degree of the pain syndrome was performed. The control group included 28 people without any pain symptoms. The method used was that of somatosensory stimulated potential (SSP) with the potentials amplitude and latency main components taken into consideration. It was proven that the true decrease of the somatosensory stimulated potential SSP N22 (p system structures and allow to reveal the subclinical slowdown of impulse conductibility, which indicates that the conducting system is changed even under a mild pain syndrome. It was found that the data obtained allow for the better understanding of how the neuropathological pain syndrome under vertebral spine pathology is formed.

  17. MEG reveals a fast pathway from somatosensory cortex to occipital areas via posterior parietal cortex in a blind subject

    DEFF Research Database (Denmark)

    Ioannides, Andreas A; Liu, Lichan; Poghosyan, Vahe

    2013-01-01

    reproducible brain responses in the primary somatosensory (S1) and motor (M1) cortices at around 20 ms post-stimulus, which were very similar in sighted and blind subjects. Time-frequency analysis revealed strong 45-70 Hz activity at latencies of 20-50 ms in S1 and M1, and posterior parietal cortex Brodmann...... areas (BA) 7 and 40, which compared to lower frequencies, were substantially more pronounced in the blind than the sighted subjects. Critically, at frequencies from α-band up to 100 Hz we found clear, strong, and widespread responses in the visual cortex of the blind subject, which increased...... with the intensity of the somatosensory stimuli. Time-delayed mutual information (MI) revealed that in blind subject the stimulus information is funneled from the early somatosensory to visual cortex through posterior parietal BA 7 and 40, projecting first to visual areas V5 and V3, and eventually V1. The flow...

  18. Early and late activity in somatosensory cortex reflects changes in bodily self-consciousness: an evoked potential study.

    Science.gov (United States)

    Aspell, J E; Palluel, E; Blanke, O

    2012-08-02

    How can we investigate the brain mechanisms underlying self-consciousness? Recent behavioural studies on multisensory bodily perception have shown that multisensory conflicts can alter bodily self-consciousness such as in the "full body illusion" (FBI) in which changes in self-identification with a virtual body and tactile perception are induced. Here we investigated whether experimental changes in self-identification during the FBI are accompanied by activity changes in somatosensory cortex by recording somatosensory-evoked potentials (SEPs). To modulate self-identification, participants were filmed by a video camera from behind while their backs were stroked, either synchronously (illusion condition) or asynchronously (control condition) with respect to the stroking seen on their virtual body. Tibial nerve SEPs were recorded during the FBI and analysed using evoked potential (EP) mapping. Tactile mislocalisation was measured using the crossmodal congruency task. SEP mapping revealed five sequential periods of brain activation during the FBI, of which two differed between the illusion condition and the control condition. Activation at 30-50 ms (corresponding to the P40 component) in primary somatosensory cortex was stronger in the illusion condition. A later activation at ∼110-200 ms, likely originating in higher-tier somatosensory regions in parietal cortex, was stronger and lasted longer in the control condition. These data show that changes in bodily self-consciousness modulate activity in primary and higher-tier somatosensory cortex at two distinct processing steps. We argue that early modulations of primary somatosensory cortex may be a consequence of (1) multisensory integration of synchronous vs. asynchronous visuo-tactile stimuli and/or (2) differences in spatial attention (to near or far space) between the conditions. The later activation in higher-tier parietal cortex (and potentially other regions in temporo-parietal and frontal cortex) likely

  19. Keeping in Touch With the Visual System: Spatial Alignment and Multisensory Integration of Visual-Somatosensory Inputs

    Directory of Open Access Journals (Sweden)

    Jeannette Rose Mahoney

    2015-08-01

    Full Text Available Correlated sensory inputs coursing along the individual sensory processing hierarchies arrive at multisensory convergence zones in cortex where inputs are processed in an integrative manner. The exact hierarchical level of multisensory convergence zones and the timing of their inputs are still under debate, although increasingly, evidence points to multisensory integration at very early sensory processing levels. The objective of the current study was to determine, both psychophysically and electrophysiologically, whether differential visual-somatosensory integration patterns exist for stimuli presented to the same versus opposite hemifields. Using high-density electrical mapping and complementary psychophysical data, we examined multisensory integrative processing for combinations of visual and somatosensory inputs presented to both left and right spatial locations. We assessed how early during sensory processing visual-somatosensory (VS interactions were seen in the event-related potential and whether spatial alignment of the visual and somatosensory elements resulted in differential integration effects. Reaction times to all VS pairings were significantly faster than those to the unisensory conditions, regardless of spatial alignment, pointing to engagement of integrative multisensory processing in all conditions. In support, electrophysiological results revealed significant differences between multisensory simultaneous VS and summed V+S responses, regardless of the spatial alignment of the constituent inputs. Nonetheless, multisensory effects were earlier in the aligned conditions, and were found to be particularly robust in the case of right-sided inputs (beginning at just 55ms. In contrast to previous work on audio-visual and audio-somatosensory inputs, the current work suggests a degree of spatial specificity to the earliest detectable multisensory integrative effects in response to visual-somatosensory pairings.

  20. Recovery of somatosensory and motor functions of the paretic upper limb in patients after stroke: Comparison of two therapeutic approaches

    Directory of Open Access Journals (Sweden)

    Kateřina Macháčková

    2016-03-01

    Full Text Available Background: Frequent and extensive disturbances to the somatosensory and motor hand functions after stroke are common. This study explores a new therapeutic approach that may improve the effectiveness of rehabilitation for these upper limb impairments. Objective: To assess the effect of rehabilitation combining standard therapy and somatosensory stimulation on sensorimotor hand functions. To compare the effect of this method with the standard method of rehabilitation. Methods: Two groups of patients were used to compare the effect of standard therapy (group A, n = 15, age = 59.8 ± 9.4 years, and the effect of therapy with targeted somatosensory stimulation (group B, n = 15, age = 65.5 ± 8.2. The groups consisted of patients after an ischemic stroke in post-acute phase, with hemiparesis, aged from 45 to 75 years, both men and women. The methods used to assess patients comprised a neurological clinical examination, two batteries of tests of somatosensory function (Rivermead Assessment of Somatosensory Performance, Fabric Matching Test, two batteries of tests of motor function (Nine Hole Peg Test, Test of Manipulation Functions, and activities of daily living assessment. Results: The results show that before therapy a deficit of somatosensory function occurred on the paretic upper limb in more than 50% of patients in both groups. Motor functions were impaired more frequently than somatosensory functions. Somatosensory stimulation therapy had an enhanced improvement of somatosensory functions, especially tactile discrimination of the object surface. Conclusions: Major improvement, particularly of tactile discrimination sensation, occurred in group B, where therapy focused on somatosensory deficit was applied. We did not show that such considerable improvement in discrimination sensation in group B was associated with any change in motor function. Clinical improvement in the motor function of the paretic limb occurred in

  1. Close to you: embodied simulation for peripersonal space in primary somatosensory cortex.

    Directory of Open Access Journals (Sweden)

    Michael Schaefer

    Full Text Available BACKGROUND: An increasing body of evidence has demonstrated that in contrast to the classic understanding the primary somatosensory cortex (SI reflects merely seen touch (in the absence of any real touch on the own body. Based on these results it has been discussed that SI may play a role in understanding touch seen on other bodies. In order to further examine this understanding of observed touch, the current study aimed to test if mirror-like responses in SI are affected by the perspective of the seen touch. Thus, we presented touch on a hand and close to the hand either in first-person-perspective or in third-person-perspective. PRINCIPAL FINDINGS: Results of functional magnetic resonance imaging (fMRI revealed stronger vicarious brain responses in SI/BA2 for touch seen in first-person-perspective. Surprisingly, the third-person viewpoint revealed activation in SI both when subjects viewed a hand being stimulated as well as when the space close to the hand was being touched. CONCLUSIONS/SIGNIFICANCE: Based on these results we conclude that vicarious somatosensory responses in SI/BA2 are affected by the viewpoint of the seen hand. Furthermore, we argue that mirror-like responses in SI do not only reflect seen touch, but also the peripersonal space surrounding this body (in third-person-perspective. We discuss these findings with recent studies on mirror responses for action observation in peripersonal space.

  2. Visual-tactile processing in primary somatosensory cortex emerges before cross-modal experience.

    Science.gov (United States)

    Bieler, Malte; Sieben, Kay; Schildt, Sandra; Röder, Brigitte; Hanganu-Opatz, Ileana L

    2017-06-01

    The presumptive unisensory neocortical areas process multisensory information by oscillatory entrainment of neuronal networks via direct cortico-cortical projections. While neonatal unimodal experience has been identified as necessary for setting up the neuronal networks of multisensory processing, it is still unclear whether early cross-modal experience equally controls the ontogeny of multisensory processing. Here, we assess the development of visual-somatosensory interactions and their anatomical substrate by performing extracellular recordings of network activity in primary sensory cortices in vivo and assessing the cortico-cortical connectivity in pigmented rats. Similar to adult animals, juvenile rats with minimal cross-modal experience display supra-additive augmentation of evoked responses, time-dependent modulation of power and phase reset of network oscillations in response to cross-modal light and whisker stimulation. Moreover, the neuronal discharge of individual neurons is stronger coupled to theta and alpha network oscillations after visual-tactile stimuli. The adult-like multisensory processing of juvenile rats relies on abundant direct visual-somatosensory connections and thalamocortical feedforward interactions. Thus, cellular and network interactions ensuring multisensory processing emerge before cross-modal experience and refine during juvenile development. © 2017 Wiley Periodicals, Inc.

  3. Transcranial magnetic stimulation over human secondary somatosensory cortex disrupts perception of pain intensity.

    Science.gov (United States)

    Lockwood, Patricia L; Iannetti, Gian Domenico; Haggard, Patrick

    2013-09-01

    Pain is a complex sensory experience resulting from the activity of a network of brain regions. However, the functional contribution of individual regions in this network remains poorly understood. We delivered single-pulse transcranial magnetic stimulation (TMS) to the contralateral primary somatosensory cortex (S1), secondary somatosensory cortex (S2) and vertex (control site) 120 msec after selective stimulation of nociceptive afferents using neodymium:yttrium-aluminium-perovskite (Nd:YAP) laser pulses causing painful sensations. Participants were required to judge either the intensity (medium/high) or the spatial location (proximal/distal) of the stimulus in a two-alternative forced choice paradigm. When TMS pulses were delivered over S2, participants' ability to judge pain intensity was disrupted, as compared to S1 and vertex (control) stimulation. Signal-detection analysis demonstrated a loss of sensitivity to stimulation intensity, rather than a shift in perceived pain level or response bias. We did not find any effect of TMS on the ability to localise nociceptive stimuli on the skin. The novel finding that TMS over S2 can disrupt perception of pain intensity suggests a causal role for S2 in encoding of pain intensity. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Resting BOLD fluctuations in the primary somatosensory cortex correlate with tactile acuity.

    Science.gov (United States)

    Haag, Lauren M; Heba, Stefanie; Lenz, Melanie; Glaubitz, Benjamin; Höffken, Oliver; Kalisch, Tobias; Puts, Nicholaas A; Edden, Richard A E; Tegenthoff, Martin; Dinse, Hubert; Schmidt-Wilcke, Tobias

    2015-03-01

    Sensory perception, including 2-point discrimination (2 ptD), is tightly linked to cortical processing of tactile stimuli in primary somatosensory cortices. While the role of cortical activity in response to a tactile stimulus has been widely investigated, the role of baseline cortical activity is largely unknown. Using resting state fMRI we investigated the relationship between local BOLD fluctuations in the primary somatosensory cortex (the representational field of the hand) and 2 ptD of the corresponding index finger (right and left). Cortical activity was measured using fractional amplitudes of the low frequency BOLD fluctuations (fALFF) and synchronicity using regional homogeneity (ReHo) of the S1 hand region during rest. 2 ptD correlated with higher ReHo values in the representational areas of the contralateral S1 cortex (left hand: p = .028; right hand: p = .049). 2 ptD additionally correlated with higher fALFF in the representational area of the left hand (p = .007) and showed a trend for a significant correlation in the representational area of the right hand (p = .051). Thus, higher BOLD amplitudes and synchronicity at rest, as measures of cortical activity and synchronicity, respectively, are related to better tactile discrimination abilities of the contralateral hand. Our findings extend the relationship seen between spontaneous BOLD fluctuations and sensory perception. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Single-unit Analysis of Somatosensory Processing in Core Auditory Cortex of Hearing Ferrets

    Science.gov (United States)

    Meredith, M. Alex; Allman, Brian L.

    2014-01-01

    The recent findings in several species that primary auditory cortex processes non-auditory information have largely overlooked the possibility for somatosensory effects. Therefore, the present investigation examined the core auditory cortices (anterior – AAF, and primary auditory-- A1, fields) for tactile responsivity. Multiple single-unit recordings from anesthetized ferret cortex yielded histologically verified neurons (n=311) tested with electronically controlled auditory, visual and tactile stimuli and their combinations. Of the auditory neurons tested, a small proportion (17%) was influenced by visual cues, but a somewhat larger number (23%) was affected by tactile stimulation. Tactile effects rarely occurred alone and spiking responses were observed in bimodal auditory-tactile neurons. However, the broadest tactile effect that was observed, which occurred in all neuron types, was that of suppression of the response to a concurrent auditory cue. The presence of tactile effects in core auditory cortices was supported by a substantial anatomical projection from the rostral suprasylvian sulcal somatosensory area. Collectively, these results demonstrate that crossmodal effects in auditory cortex are not exclusively visual and that somatosensation plays a significant role in modulation of acoustic processing and indicate that crossmodal plasticity following deafness may unmask these existing non-auditory functions. PMID:25728185

  6. Anatomical Correlates of Local, Translaminar, and Transcolumnar Inhibition by Layer 6 GABAergic Interneurons in Somatosensory Cortex.

    Science.gov (United States)

    Arzt, Marlene; Sakmann, Bert; Meyer, Hanno S

    2017-07-18

    In the vibrissal area of rodent somatosensory cortex, information on whisker stimulation is processed by neuronal networks in a corresponding cortical column. To understand how sensory stimuli are represented in a column, it is essential to identify cell types constituting these networks. Layer 6 (L6) comprises 25% of all neurons in a column. In rats, 430 of these are inhibitory interneurons (INs). Little is known about the axon projection of L6 INs with reference to columnar and laminar organization. We quantified axonal projections of L6 INs (n = 68) with reference to columns and layers in somatosensory cortex of rats. We found distinct projection types differentially targeting layers of a cortical column. The majority of L6 INs did not show a column-specific innervation, densely projecting to neighboring columns as well as the home column. However, a small fraction targeted granular and supragranular layers, where axon projections were confined to the home column. We also quantified putative innervation of pyramidal cells as a functional correlate of axonal distribution. Electrophysiological properties were not correlated to axon projection. The quantitative data on axonal projections and electrophysiological properties of L6 INs can guide future studies investigating cortical processing of sensory information at the single cell level. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  7. Vestibular signal processing in a subject with somatosensory deafferentation: The case of sitting posture

    Directory of Open Access Journals (Sweden)

    Teasdale Normand

    2007-08-01

    Full Text Available Abstract Background The vestibular system of the inner ear provides information about head translation/rotation in space and about the orientation of the head with respect to the gravitoinertial vector. It also largely contributes to the control of posture through vestibulospinal pathways. Testing an individual severely deprived of somatosensory information below the nose, we investigated if equilibrium can be maintained while seated on the sole basis of this information. Results Although she was unstable, the deafferented subject (DS was able to remain seated with the eyes closed in the absence of feet, arm and back supports. However, with the head unconsciously rotated towards the left or right shoulder, the DS's instability markedly increased. Small electrical stimulations of the vestibular apparatus produced large body tilts in the DS contrary to control subjects who did not show clear postural responses to the stimulations. Conclusion The results of the present experiment show that in the lack of vision and somatosensory information, vestibular signal processing allows the maintenance of an active sitting posture (i.e. without back or side rests. When head orientation changes with respect to the trunk, in the absence of vision, the lack of cervical information prevents the transformation of the head-centered vestibular information into a trunk-centered frame of reference of body motion. For the normal subjects, this latter frame of reference enables proper postural adjustments through vestibular signal processing, irrespectively of the orientation of the head with respect to the trunk.

  8. Increased responses in the somatosensory thalamus immediately after spinal cord injury.

    Science.gov (United States)

    Alonso-Calviño, E; Martínez-Camero, I; Fernández-López, E; Humanes-Valera, D; Foffani, G; Aguilar, J

    2016-03-01

    Spinal cord injury (SCI) involves large-scale deafferentation of supraspinal structures in the somatosensory system, producing well-known long-term effects at the thalamo-cortical level. We recently showed that SCI provokes immediate changes in cortical spontaneous and evoked responses and here, we have performed a similar study to define the immediate changes produced in the thalamic ventro-postero-lateral nucleus (VPL) that are associated with the forepaw and hindpaw circuits. Extracellular electrophysiological recordings from the VPL reflected the spontaneous activity and the responses to peripheral electrical stimulation applied to the paws. Accordingly, the activity of the neuronal populations recorded at specific thalamic locations that correspond to the forepaw and hindpaw circuits was recorded under control conditions and immediately after thoracic SCI. The results demonstrate that peripheral inputs from both extremities overlap on neuronal populations in the somatosensory thalamus. In addition, they show that the responses of thalamic neurons to forepaw and hindpaw stimuli are increased immediately after SCI, in association with a specific decrease in spontaneous activity in the hindpaw locations. Finally, the increased thalamic responses after SCI have a state-dependent component in relation with cortical activity. Together, our results indicate that the thalamic changes occurring immediately after SCI could contribute to the cortical changes also detected immediately after such spinal lesions. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  9. Somatosensory Evoked Potentials suppression due to remifentanil during spinal operations; a prospective clinical study

    Directory of Open Access Journals (Sweden)

    Christodoulou Anastasios

    2010-05-01

    Full Text Available Abstract Background Somatosensory evoked potentials (SSEP are being used for the investigation and monitoring of the integrity of neural pathways during surgical procedures. Intraoperative neurophysiologic monitoring is affected by the type of anesthetic agents. Remifentanil is supposed to produce minimal or no changes in SSEP amplitude and latency. This study aims to investigate whether high doses of remifentanil influence the SSEP during spinal surgery under total intravenous anesthesia. Methods Ten patients underwent spinal surgery. Anesthesia was induced with propofol (2 mg/Kg, fentanyl (2 mcg/Kg and a single dose of cis-atracurium (0.15 mg/Kg, followed by infusion of 0.8 mcg/kg/min of remifentanil and propofol (30-50 mcg/kg/min. The depth of anesthesia was monitored by Bispectral Index (BIS and an adequate level (40-50 of anesthesia was maintained. Somatosensory evoked potentials (SSEPs were recorded intraoperatively from the tibial nerve (P37 15 min before initiation of remifentanil infusion. Data were analysed over that period. Results Remifentanil induced prolongation of the tibial SSEP latency which however was not significant (p > 0.05. The suppression of the amplitude was significant (p Conclusion Remifentanil in high doses induces significant changes in SSEP components that should be taken under consideration during intraoperative neuromonitoring.

  10. Brain volume analyses and somatosensory evoked potentials in multiple system atrophy.

    Science.gov (United States)

    Miyatake, Satoko; Mochizuki, Hitoshi; Naka, Tetsuji; Ugawa, Yoshikazu; Tanabe, Hajime; Kuzume, Daisuke; Suzuki, Mikiya; Ogata, Katsuhisa; Kawai, Mitsuru

    2010-03-01

    We investigated a progression of brain atrophy and somatosensory system dysfunction in multiple system atrophy (MSA). Subjects were 21 MSA patients [12 MSA-C (cerebellar type) and 9 MSA-P (parkinsonism type)]. The relative volumes of cerebrum, brainstem and cerebellum to the intracranial volume were obtained from three-dimensional computed tomography (3D-CT) of the brain. The median nerve somatosensory evoked potentials (SEPs) were recorded, and the latencies and amplitudes of N9, N11, P13/14, N20 and P25 components were measured. We studied correlations between brain volumes, SEP and clinical features. The brainstem and cerebellar atrophies were aggravated with progression of the disease. The central sensory conduction time (CSCT) was progressively prolonged in parallel with the disease duration irrespective of the actual age of the patients. In MSA patients, the volume reductions of cerebellum and brainstem could be one of structural markers of disease progression, and the sensory pathway is progressively involved with the progression of disease processes.

  11. The Role of Somatosensory Information in Speech Perception: Imitation Improves Recognition of Disordered Speech.

    Science.gov (United States)

    Borrie, Stephanie A; Schäfer, Martina C M

    2015-12-01

    Perceptual learning paradigms involving written feedback appear to be a viable clinical tool to reduce the intelligibility burden of dysarthria. The underlying theoretical assumption is that pairing the degraded acoustics with the intended lexical targets facilitates a remapping of existing mental representations in the lexicon. This study investigated whether ties to mental representations can be strengthened by way of a somatosensory motor trace. Following an intelligibility pretest, 100 participants were assigned to 1 of 5 experimental groups. The control group received no training, but the other 4 groups received training with dysarthric speech under conditions involving a unique combination of auditory targets, written feedback, and/or a vocal imitation task. All participants then completed an intelligibility posttest. Training improved intelligibility of dysarthric speech, with the largest improvements observed when the auditory targets were accompanied by both written feedback and an imitation task. Further, a significant relationship between intelligibility improvement and imitation accuracy was identified. This study suggests that somatosensory information can strengthen the activation of speech sound maps of dysarthric speech. The findings, therefore, implicate a bidirectional relationship between speech perception and speech production as well as advance our understanding of the mechanisms that underlie perceptual learning of degraded speech.

  12. Transcriptional profiling at whole population and single cell levels reveals somatosensory neuron molecular diversity

    Science.gov (United States)

    Chiu, Isaac M; Barrett, Lee B; Williams, Erika K; Strochlic, David E; Lee, Seungkyu; Weyer, Andy D; Lou, Shan; Bryman, Gregory S; Roberson, David P; Ghasemlou, Nader; Piccoli, Cara; Ahat, Ezgi; Wang, Victor; Cobos, Enrique J; Stucky, Cheryl L; Ma, Qiufu; Liberles, Stephen D; Woolf, Clifford J

    2014-01-01

    The somatosensory nervous system is critical for the organism's ability to respond to mechanical, thermal, and nociceptive stimuli. Somatosensory neurons are functionally and anatomically diverse but their molecular profiles are not well-defined. Here, we used transcriptional profiling to analyze the detailed molecular signatures of dorsal root ganglion (DRG) sensory neurons. We used two mouse reporter lines and surface IB4 labeling to purify three major non-overlapping classes of neurons: 1) IB4+SNS-Cre/TdTomato+, 2) IB4−SNS-Cre/TdTomato+, and 3) Parv-Cre/TdTomato+ cells, encompassing the majority of nociceptive, pruriceptive, and proprioceptive neurons. These neurons displayed distinct expression patterns of ion channels, transcription factors, and GPCRs. Highly parallel qRT-PCR analysis of 334 single neurons selected by membership of the three populations demonstrated further diversity, with unbiased clustering analysis identifying six distinct subgroups. These data significantly increase our knowledge of the molecular identities of known DRG populations and uncover potentially novel subsets, revealing the complexity and diversity of those neurons underlying somatosensation. DOI: http://dx.doi.org/10.7554/eLife.04660.001 PMID:25525749

  13. Determination of health anxiety, anxiety, and somatosensory amplification levels in individuals with normal coronary angiography.

    Science.gov (United States)

    Korkmaz, Hasan; Korkmaz, Sevda; Yildiz, Sevler; Gündoğan, Burcu; Atmaca, Murad

    2017-06-01

    The objective of the present study is to determine the somatosensory amplification, anxiety, and depression levels in patients with normal coronary arteries. Thirty-five patients with normal coronary arteries and 35 healthy individuals of similar age and gender as the patient group were included in the study. Somatosensory Amplification Scale (SSAS), Health Anxiety Inventory (HAI-18), Penn State Anxiety Scale (PSWQ), Beck Anxiety Inventory (BAI), and Beck Depression Inventory (BDI) were applied to all participants. Comparison of the patient group with the control group demonstrated that SSAS (22.7±8.2; 18.5±5.98; p=0.018), BAI (15.4±9.43; 9.4±7.3; p=0.004), BDI (24.9±13.5; 13.7±7.5; panxiety and depression scores were higher than those of healthy individuals. Thus, the necessity of these interventions should be assessed in detail in the future. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  14. [The central action of botulinum toxin type A assessed by brain auditory and somatosensory evoked potentials].

    Science.gov (United States)

    Sławek, Jarosław; Recławowicz, Daniel

    2004-01-01

    Botulinum toxin type A (BTX-A) acts as a neuromuscular blocker in the release of acetylcholine. Nevertheless, some clinical effects and side effects are difficult to explain only due to the peripheral mode of action. The aim of the study was to assess the central effects of BTX-A by measuring the two modalities of evoked potentials (somatosensory and brain-stem auditory). In 23 patients (13 females, 10 males, mean age of 46, range of 25-71) with idiopathic cervical dystonia (never treated with BTX-A) brainstem auditory evoked responses (BAER) and somatosensory evoked potentials from upper extremities (SEP) were performed before and 4-6 weeks after BTX-A administration. BTX-A (Botox in 14 patients, Dysport in 9 patients) was injected into neck muscles: sternocleidomastoideus, splenius capitis, trapezius and levator scapulae. The authors did not find any statistically significant differences in basic parameters (latency and interlatency of I, III, V in BAER and N9, N13, N20 and P25 responses in SEP) before and after BTX-A administration. It seems that BTX-A does not have any direct central effect or the methods are not sensitive enough to detect them. Remote (anatomically distant) clinical effects seen by other authors or side effects may be explained by indirect mechanism due to deafferentation of stimuli from muscle spindles after BTX-A injection and thus modifying the central loops of reflexes or due to unpredictable hematogenous spread of BTX-A to distant muscles.

  15. Effects of white noise on event-related potentials in somatosensory Go/No-go paradigms.

    Science.gov (United States)

    Ohbayashi, Wakana; Kakigi, Ryusuke; Nakata, Hiroki

    2017-09-06

    Exposure to auditory white noise has been shown to facilitate human cognitive function. This phenomenon is termed stochastic resonance, and a moderate amount of auditory noise has been suggested to benefit individuals in hypodopaminergic states. The present study investigated the effects of white noise on the N140 and P300 components of event-related potentials in somatosensory Go/No-go paradigms. A Go or No-go stimulus was presented to the second or fifth digit of the left hand, respectively, at the same probability. Participants performed somatosensory Go/No-go paradigms while hearing three different white noise levels (45, 55, and 65 dB conditions). The peak amplitudes of Go-P300 and No-go-P300 in ERP waveforms were significantly larger under 55 dB than 45 and 65 dB conditions. White noise did not affect the peak latency of N140 or P300, or the peak amplitude of N140. Behavioral data for the reaction time, SD of reaction time, and error rates showed the absence of an effect by white noise. This is the first event-related potential study to show that exposure to auditory white noise at 55 dB enhanced the amplitude of P300 during Go/No-go paradigms, reflecting changes in the neural activation of response execution and inhibition processing.

  16. [Brainstem auditory evoked potentials and somatosensory evoked potentials in Chiari malformation].

    Science.gov (United States)

    Moncho, Dulce; Poca, María A; Minoves, Teresa; Ferré, Alejandro; Rahnama, Kimia; Sahuquillo, Juan

    2013-06-16

    Chiari malformations (CM) include a series of congenital anomalies involving the descent of the cerebellar tonsils below the foramen magnum, which may be associated with compression in the brainstem, upper spinal cord, and cranial nerves, consequently altering the responses of brainstem auditory evoked potentials (BAEP) and somatosensory evoked potentials (SSEP). However, only a small number of authors have described the indications of these tests in CM, and study groups to date have been small and heterogeneous. To review the results of BAEPs and SSEPs in published studies of patients with Chiari type 1 malformation (CM-1) or Chiari type 2 malformation (CM-2) as well as the indications of both tests in the diagnosis, treatment, and monitoring of both diseases, especially CM-1. We present a review article analyzing data from all published studies in Medline starting in 1966, located through PubMed, using combinations of the following keywords: 'Chiari malformation', 'Arnold-Chiari malformation', 'Chiari type 1 malformation', 'Arnold-Chiari type 1 malformation', 'evoked potentials', 'brainstem auditory evoked potentials' and 'somatosensory evoked potentials' as well as records of patients with CM-1 from the neurosurgery and neurophysiology departments at the Hospital Universitari Vall d'Hebron. Common findings of SSEP are a reduction in cortical amplitude from the posterior tibial nerve, a reduction or absence of cervical median nerve potential, and an increased N13-N20 interval. In BAEP, the most frequent findings are an increased I-V interval and a peripheral or cochlear auditory disturbance.

  17. Rewiring the primary somatosensory cortex in carpal tunnel syndrome with acupuncture.

    Science.gov (United States)

    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; Napadow, Vitaly

    2017-04-01

    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

  18. A cumulant functional for static and dynamic correlation

    International Nuclear Information System (INIS)

    Hollett, Joshua W.; Hosseini, Hessam; Menzies, Cameron

    2016-01-01

    A functional for the cumulant energy is introduced. The functional is composed of a pair-correction and static and dynamic correlation energy components. The pair-correction and static correlation energies are functionals of the natural orbitals and the occupancy transferred between near-degenerate orbital pairs, rather than the orbital occupancies themselves. The dynamic correlation energy is a functional of the statically correlated on-top two-electron density. The on-top density functional used in this study is the well-known Colle-Salvetti functional. Using the cc-pVTZ basis set, the functional effectively models the bond dissociation of H 2 , LiH, and N 2 with equilibrium bond lengths and dissociation energies comparable to those provided by multireference second-order perturbation theory. The performance of the cumulant functional is less impressive for HF and F 2 , mainly due to an underestimation of the dynamic correlation energy by the Colle-Salvetti functional.

  19. Cumulative Risks of Foster Care Placement for Danish Children

    DEFF Research Database (Denmark)

    Fallesen, Peter; Emanuel, Natalia; Wildeman, Christopher

    2014-01-01

    foster care placement is salient in other contexts. In this article, we provide companion estimates to those provided in recent work on the US by using Danish registry data and synthetic cohort life tables to show how high and unequally distributed the cumulative risk of foster care placement...... is for Danish children. Results suggest that at the beginning of the study period (in 1998) the cumulative risk of foster care placement for Danish children was roughly in line with the risk for American children. Yet, by the end of the study period (2010), the risk had declined to half the risk for American...... (especially at the beginning of the study period), the age-specific risk profiles are markedly different, with higher risks for older Danish children than for older American children....

  20. Spin effects at fragmentation of polarized deuterons into cumulative pions

    International Nuclear Information System (INIS)

    Afanasiev, S.; Arkhipov, V.; Bondarev, V.; Isupov, A.; Khrenov, A.; Kirillov, D.; Ladygin, V.; Litvinenko, A.; Malakhov, A.; Pilipenko, Yu.; Reznikov, S.; Rukoyatkin, P.; Zolin, L.; Daito, I.; Horikawa, N.; Wakai, A.; Doushita, N.; Fukui, S.; Iwata, T.; Kondo, K.

    2002-01-01

    Tensor analyzing power T 20 of the reaction d-vectorA→π(0 deg.)X was measured in the fragmentation of 9 GeV deuterons into points with the momenta from 3.5 to 5.3 GeV/c at hydrogen, beryllium and carbon targets. This momentum range corresponds to region of cumulative pion production The values of T 20 are found to be small and consistent with positive values in contradiction with the Impulse Approximation calculations based on assuming a direct mechanism of pion production (NN→NNπ). New data on tensor Ayy analyzing power for pion production at the non-zero angle (θ π =135,180mr) with pion transverse momenta up to P t =0.8 GeV/c are presented. Ayy increases with rise of P t in the cumulative region

  1. Experience of cumulative effects assessment in the UK

    Directory of Open Access Journals (Sweden)

    Piper Jake

    2004-01-01

    Full Text Available Cumulative effects assessment (CEA is a development of environmental impact assessment which attempts to take into account the wider picture of what impacts may affect the environment as a result of either multiple or linear projects, or development plans. CEA is seen as a further valuable tool in promoting sustainable development. The broader canvas upon which the assessment is made leads to a suite of issues such as complexity in methods and assessment of significance, the desirability of co-operation between developers and other parties, new ways of addressing mitigation and monitoring. After outlining the legislative position and the process of CEA, this paper looks at three cases studies in the UK where cumulative assessment has been carried out - the cases concern wind farms, major infrastructure and off-shore developments.

  2. Ecosystem assessment methods for cumulative effects at the regional scale

    International Nuclear Information System (INIS)

    Hunsaker, C.T.

    1989-01-01

    Environmental issues such as nonpoint-source pollution, acid rain, reduced biodiversity, land use change, and climate change have widespread ecological impacts and require an integrated assessment approach. Since 1978, the implementing regulations for the National Environmental Policy Act (NEPA) have required assessment of potential cumulative environmental impacts. Current environmental issues have encouraged ecologists to improve their understanding of ecosystem process and function at several spatial scales. However, management activities usually occur at the local scale, and there is little consideration of the potential impacts to the environmental quality of a region. This paper proposes that regional ecological risk assessment provides a useful approach for assisting scientists in accomplishing the task of assessing cumulative impacts. Critical issues such as spatial heterogeneity, boundary definition, and data aggregation are discussed. Examples from an assessment of acidic deposition effects on fish in Adirondack lakes illustrate the importance of integrated data bases, associated modeling efforts, and boundary definition at the regional scale

  3. Finite-volume cumulant expansion in QCD-colorless plasma

    Energy Technology Data Exchange (ETDEWEB)

    Ladrem, M. [Taibah University, Physics Department, Faculty of Science, Al-Madinah, Al-Munawwarah (Saudi Arabia); Physics Department, Algiers (Algeria); ENS-Vieux Kouba (Bachir El-Ibrahimi), Laboratoire de Physique et de Mathematiques Appliquees (LPMA), Algiers (Algeria); Ahmed, M.A.A. [Taibah University, Physics Department, Faculty of Science, Al-Madinah, Al-Munawwarah (Saudi Arabia); ENS-Vieux Kouba (Bachir El-Ibrahimi), Laboratoire de Physique et de Mathematiques Appliquees (LPMA), Algiers (Algeria); Taiz University in Turba, Physics Department, Taiz (Yemen); Alfull, Z.Z. [Taibah University, Physics Department, Faculty of Science, Al-Madinah, Al-Munawwarah (Saudi Arabia); Cherif, S. [ENS-Vieux Kouba (Bachir El-Ibrahimi), Laboratoire de Physique et de Mathematiques Appliquees (LPMA), Algiers (Algeria); Ghardaia University, Sciences and Technologies Department, Ghardaia (Algeria)

    2015-09-15

    Due to the finite-size effects, the localization of the phase transition in finite systems and the determination of its order, become an extremely difficult task, even in the simplest known cases. In order to identify and locate the finite-volume transition point T{sub 0}(V) of the QCD deconfinement phase transition to a colorless QGP, we have developed a new approach using the finite-size cumulant expansion of the order parameter and the L{sub mn}-method. The first six cumulants C{sub 1,2,3,4,5,6} with the corresponding under-normalized ratios (skewness Σ, kurtosis κ, pentosis Π{sub ±}, and hexosis H{sub 1,2,3}) and three unnormalized combinations of them, (O = σ{sup 2}κΣ{sup -1},U = σ{sup -2}Σ{sup -1},N = σ{sup 2}κ) are calculated and studied as functions of (T, V). A new approach, unifying in a clear and consistent way the definitions of cumulant ratios, is proposed.Anumerical FSS analysis of the obtained results has allowed us to locate accurately the finite-volume transition point. The extracted transition temperature value T{sub 0}(V) agrees with that expected T{sub 0}{sup N}(V) from the order parameter and the thermal susceptibility χ{sub T} (T, V), according to the standard procedure of localization to within about 2%. In addition to this, a very good correlation factor is obtained proving the validity of our cumulants method. The agreement of our results with those obtained by means of other models is remarkable. (orig.)

  4. A modelling framework for MSP-oriented cumulative effects assessment

    OpenAIRE

    Stefano Menegon; Daniel Depellegrin; Giulio Farella; Elena Gissi; Michol Ghezzo; Alessandro Sarretta; Chiara Venier; Andrea Barbanti

    2018-01-01

    This research presents a comprehensive Cumulative Eects Assessment (CEA) based on the Tools4MSP modelling framework tested for the Italian Adriatic Sea. The CEA incorporates ve methodological advancements: (1) linear and non-linear ecosystem response to anthropogenic pressures/effects, (2) modelling of additive, dominant and antagonist stressor effects, (3) implementation of a convolution distance model for stressor dispersion modelling, (4) application of a CEA backsourcing (CEA-B) model to ...

  5. Heavy metal cumulation in crops after the sewage sludge application

    Directory of Open Access Journals (Sweden)

    Gondová Andrea

    1998-12-01

    Full Text Available During 1995 - 1996 the crops samples after the sewage sludge application were collected. The heavy metals cumulation in investigated crops from Bardejov increased in order: Zn > Cu > Pb > Ni > Cr > Cd and Banská Bystrica : Zn > Cu > Cr > Ni > Pb > Cd. Heavy metals contents after the sewage sludge application were increased in comparison with the highest admissible concentration in eatable part of crops. The sewage sludge application were not recommended in soils for the growth of vegetables

  6. Cumulative incidence rates of the mucopolysaccharidoses in Germany.

    Science.gov (United States)

    Baehner, F; Schmiedeskamp, C; Krummenauer, F; Miebach, E; Bajbouj, M; Whybra, C; Kohlschütter, A; Kampmann, C; Beck, M

    2005-01-01

    In order to estimate the cumulative incidence rates of the mucopolysaccharidoses (MPS) in Germany, a retrospective epidemiological survey covering the period between 1980 and 1995 was implemented. Multiple ascertainment sources were used to identify affected patients. A prevalence of approximately 0.69 cases per 100,000 births was obtained for MPS I (Hurler phenotype). Within the study period, 4 patients with Hurler/Scheie phenotype and 7 cases with Scheie disease were detected. The cumulative incidence for MPS II (Hunter syndrome) was estimated as 0.64 cases per 100,000 births (1.3 cases per 100,000 male live births); that for MPS III (Sanfilippo syndrome types A, B and C) as 1.57 cases in 100,000 births; that for MPS IV A (Morquio syndrome) as 0.38 cases in 100,000; and that for MPS VI (Maroteaux-Lamy syndrome) as 0.23 cases per 100,000 births. Two cases of MPS IVB (beta-galactosidase deficiency) have been identified, but no patients with MPS VII or MPS IX. A relatively high number of patients with MPS IIIB, MPS IVA and MPS VI were of Turkish origin. The crude rate for all types of mucopolysaccharidoses is approximately 3.53 cases in 100,000 live births. The cumulative incidence pattern of MPS in Germany was compared with the corresponding rates among other industrial nations obtained from recent literature: the crude cumulative rates for all types of mucopolysaccharidoses (3.4-4.5 in 100,000 live births) were similar among all published populations; however, different frequencies of the various forms of MPS were observed.

  7. Psoriasis: is the impairment to a patient's life cumulative?

    Science.gov (United States)

    Kimball, A B; Gieler, U; Linder, D; Sampogna, F; Warren, R B; Augustin, M

    2010-09-01

    Psoriasis is associated with significant physical and psychological burden affecting all facets of a patient's life--relationships, social activities, work and emotional wellbeing. The cumulative effect of this disability may be self-perpetuating social disconnection and failure to achieve a 'full life potential' in some patients. Health-related quality of life studies have quantified the burden of psoriasis providing predominantly cross-sectional data and point-in-time images of patients' lives rather than assessing the possible cumulative disability over a patient's lifetime. However, social and economic outcomes indicate there are likely negative impacts that accumulate over time. To capture the cumulative effect of psoriasis and its associated co-morbidities and stigma over a patient's life course, we propose the concept of 'Cumulative Life Course Impairment' (CLCI). CLCI results from an interaction between (A) the burden of stigmatization, and physical and psychological co-morbidities and (B) coping strategies and external factors. Several key aspects of the CLCI concept are supported by data similar to that used in health-related quality of life assessments. Future research should focus on (i) establishing key components of CLCI and determining the mechanisms of impairment through longitudinal or retrospective case-control studies, and (ii) assessing factors that put patients at increased risk of developing CLCI. In the future, this concept may lead to a better understanding of the overall impact of psoriasis, help identify more vulnerable patients, and facilitate more appropriate treatment decisions or earlier referrals. To our knowledge, this is a first attempt to apply and develop concepts from 'Life Course Epidemiology' to psoriasis research.

  8. Seasonal climate change patterns due to cumulative CO2 emissions

    Science.gov (United States)

    Partanen, Antti-Ilari; Leduc, Martin; Damon Matthews, H.

    2017-07-01

    Cumulative CO2 emissions are near linearly related to both global and regional changes in annual-mean surface temperature. These relationships are known as the transient climate response to cumulative CO2 emissions (TCRE) and the regional TCRE (RTCRE), and have been shown to remain approximately constant over a wide range of cumulative emissions. Here, we assessed how well this relationship holds for seasonal patterns of temperature change, as well as for annual-mean and seasonal precipitation patterns. We analyzed an idealized scenario with CO2 concentration growing at an annual rate of 1% using data from 12 Earth system models from the Coupled Model Intercomparison Project Phase 5 (CMIP5). Seasonal RTCRE values for temperature varied considerably, with the highest seasonal variation evident in the Arctic, where RTCRE was about 5.5 °C per Tt C for boreal winter and about 2.0 °C per Tt C for boreal summer. Also the precipitation response in the Arctic during boreal winter was stronger than during other seasons. We found that emission-normalized seasonal patterns of temperature change were relatively robust with respect to time, though they were sub-linear with respect to emissions particularly near the Arctic. Moreover, RTCRE patterns for precipitation could not be quantified robustly due to the large internal variability of precipitation. Our results suggest that cumulative CO2 emissions are a useful metric to predict regional and seasonal changes in precipitation and temperature. This extension of the TCRE framework to seasonal and regional climate change is helpful for communicating the link between emissions and climate change to policy-makers and the general public, and is well-suited for impact studies that could make use of estimated regional-scale climate changes that are consistent with the carbon budgets associated with global temperature targets.

  9. Cumulative culture can emerge from collective intelligence in animal groups

    OpenAIRE

    Sasaki, Takao; Biro, Dora

    2017-01-01

    Studies of collective intelligence in animal groups typically overlook potential improvement through learning. Although knowledge accumulation is recognised as a major advantage of group living within the framework of Cumulative Cultural Evolution (CCE), the interplay between CCE and collective intelligence has remained unexplored. Here, we use homing pigeons to investigate whether the repeated removal and replacement of individuals in experimental groups (a key method in testing for CCE) alt...

  10. Cumulative Risk Assessment Toolbox: Methods and Approaches for the Practitioner

    Directory of Open Access Journals (Sweden)

    Margaret M. MacDonell

    2013-01-01

    Full Text Available The historical approach to assessing health risks of environmental chemicals has been to evaluate them one at a time. In fact, we are exposed every day to a wide variety of chemicals and are increasingly aware of potential health implications. Although considerable progress has been made in the science underlying risk assessments for real-world exposures, implementation has lagged because many practitioners are unaware of methods and tools available to support these analyses. To address this issue, the US Environmental Protection Agency developed a toolbox of cumulative risk resources for contaminated sites, as part of a resource document that was published in 2007. This paper highlights information for nearly 80 resources from the toolbox and provides selected updates, with practical notes for cumulative risk applications. Resources are organized according to the main elements of the assessment process: (1 planning, scoping, and problem formulation; (2 environmental fate and transport; (3 exposure analysis extending to human factors; (4 toxicity analysis; and (5 risk and uncertainty characterization, including presentation of results. In addition to providing online access, plans for the toolbox include addressing nonchemical stressors and applications beyond contaminated sites and further strengthening resource accessibility to support evolving analyses for cumulative risk and sustainable communities.

  11. 4D Near-Field Source Localization Using Cumulant

    Directory of Open Access Journals (Sweden)

    Junying Zhang

    2007-01-01

    Full Text Available This paper proposes a new cumulant-based algorithm to jointly estimate four-dimensional (4D source parameters of multiple near-field narrowband sources. Firstly, this approach proposes a new cross-array, and constructs five high-dimensional Toeplitz matrices using the fourth-order cumulants of some properly chosen sensor outputs; secondly, it forms a parallel factor (PARAFAC model in the cumulant domain using these matrices, and analyzes the unique low-rank decomposition of this model; thirdly, it jointly estimates the frequency, two-dimensional (2D directions-of-arrival (DOAs, and range of each near-field source from the matrices via the low-rank three-way array (TWA decomposition. In comparison with some available methods, the proposed algorithm, which efficiently makes use of the array aperture, can localize N−3 sources using N sensors. In addition, it requires neither pairing parameters nor multidimensional search. Simulation results are presented to validate the performance of the proposed method.

  12. 4D Near-Field Source Localization Using Cumulant

    Directory of Open Access Journals (Sweden)

    Zhao Feng

    2007-01-01

    Full Text Available This paper proposes a new cumulant-based algorithm to jointly estimate four-dimensional (4D source parameters of multiple near-field narrowband sources. Firstly, this approach proposes a new cross-array, and constructs five high-dimensional Toeplitz matrices using the fourth-order cumulants of some properly chosen sensor outputs; secondly, it forms a parallel factor (PARAFAC model in the cumulant domain using these matrices, and analyzes the unique low-rank decomposition of this model; thirdly, it jointly estimates the frequency, two-dimensional (2D directions-of-arrival (DOAs, and range of each near-field source from the matrices via the low-rank three-way array (TWA decomposition. In comparison with some available methods, the proposed algorithm, which efficiently makes use of the array aperture, can localize sources using sensors. In addition, it requires neither pairing parameters nor multidimensional search. Simulation results are presented to validate the performance of the proposed method.

  13. Multiway Filtering Based on Fourth-Order Cumulants

    Directory of Open Access Journals (Sweden)

    Salah Bourennane

    2005-05-01

    Full Text Available We propose a new multiway filtering based on fourth-order cumulants for the denoising of noisy data tensor with correlated Gaussian noise. The classical multiway filtering is based on the TUCKALS3 algorithm that computes a lower-rank tensor approximation. The presented method relies on the statistics of the analyzed multicomponent signal. We first recall how the well-known lower rank-(K1,…,KN tensor approximation processed by TUCKALS3 alternating least square algorithm exploits second-order statistics. Then, we propose to introduce the fourth-order statistics in the TUCKALS3-based method. Indeed, the use of fourth-order cumulants enables to remove the Gaussian components of an additive noise. In the presented method the estimation of the n-mode projector on the n-mode signal subspace are built from the eigenvectors associated with the largest eigenvalues of a fourth-order cumulant slice matrix instead of a covariance matrix. Each projector is applied by means of the n-mode product operator on the n-mode of the data tensor. The qualitative results of the improved multiway TUCKALS3-based filterings are shown for the case of noise reduction in a color image and multicomponent seismic data.

  14. Preference, resistance to change, and the cumulative decision model.

    Science.gov (United States)

    Grace, Randolph C

    2018-01-01

    According to behavioral momentum theory (Nevin & Grace, 2000a), preference in concurrent chains and resistance to change in multiple schedules are independent measures of a common construct representing reinforcement history. Here I review the original studies on preference and resistance to change in which reinforcement variables were manipulated parametrically, conducted by Nevin, Grace and colleagues between 1997 and 2002, as well as more recent research. The cumulative decision model proposed by Grace and colleagues for concurrent chains is shown to provide a good account of both preference and resistance to change, and is able to predict the increased sensitivity to reinforcer rate and magnitude observed with constant-duration components. Residuals from fits of the cumulative decision model to preference and resistance to change data were positively correlated, supporting the prediction of behavioral momentum theory. Although some questions remain, the learning process assumed by the cumulative decision model, in which outcomes are compared against a criterion that represents the average outcome value in the current context, may provide a plausible model for the acquisition of differential resistance to change. © 2018 Society for the Experimental Analysis of Behavior.

  15. Cumulative trauma, PTSD and dissociation among Ethiopian refugees in Israel.

    Science.gov (United States)

    Finklestein, Michal; Solomon, Zahava

    2009-01-01

    The aim of this study was to examine the exposure of Ethiopian refugees to pre-, peri- and post-migration stressful events and their implications for both posttraumatic stress disorder (PTSD) and dissociation. A random sample (N = 478) of three groups of refugees took part in the research ("Moses" immigrants, 1984, n = 165; "Solomon" immigrants, 1991, n = 169; "Family Reunification" immigrants, 1995, n = 144). Exposure to stressful events and posttraumatic symptoms were assessed via the Harvard Trauma Questionnaire (HTQ). Post-migration difficulties were assessed via the Post Migration Living Difficulties (PMLD) scale. Dissociation was evaluated using the Dissociation Experience Scale (DES). Significant differences were found among the groups in the rates of PTSD (27%, 15%, and 26%, respectively), but no differences were found in dissociation. A significant relationship was found between PTSD symptoms and cumulative trauma among the three groups, but no such relationship was found between dissociation and cumulative trauma. The differences among the groups were discussed in light of the unique characteristics of cumulative trauma, PTSD and dissociation among Ethiopian refugees.

  16. Dynamic prediction of cumulative incidence functions by direct binomial regression.

    Science.gov (United States)

    Grand, Mia K; de Witte, Theo J M; Putter, Hein

    2018-03-25

    In recent years there have been a series of advances in the field of dynamic prediction. Among those is the development of methods for dynamic prediction of the cumulative incidence function in a competing risk setting. These models enable the predictions to be updated as time progresses and more information becomes available, for example when a patient comes back for a follow-up visit after completing a year of treatment, the risk of death, and adverse events may have changed since treatment initiation. One approach to model the cumulative incidence function in competing risks is by direct binomial regression, where right censoring of the event times is handled by inverse probability of censoring weights. We extend the approach by combining it with landmarking to enable dynamic prediction of the cumulative incidence function. The proposed models are very flexible, as they allow the covariates to have complex time-varying effects, and we illustrate how to investigate possible time-varying structures using Wald tests. The models are fitted using generalized estimating equations. The method is applied to bone marrow transplant data and the performance is investigated in a simulation study. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Autonomous Magneto-Cumulative Energy Source Based on Permanent Magnets

    Science.gov (United States)

    Gurin, V. E.; Boriskin, A. S.; Vlasov, Yu. V.; Golosov, S. N.; Dimant, E. M.; Demidov, V. A.; Kazakov, S. A.; Kazakova, N. R.; Klimashov, M. V.; Korolev, P. V.; Kutumov, S. V.; Pikar, A. S.; Romanov, A. P.; Shapovalov, E. V.; Shibitov, Yu. M.; Shchetnikov, E. I.; Yanenko, V. A.

    2006-08-01

    In the paper we describe a design of autonomous source of electromagnetic energy with initial field, created by permanent barium oxide magnets and present results of its tests. The energy source consists of magnetic system with initial energy of 1 J, helical magneto-cumulative generator with helix diameter of 50 mm, amplifying the field energy in 130 times, and transforming unit for a load matching. At peak power on helical generator of 66 MW, the voltage of 16 kV was obtained at inductive load of 40 μH. Weight of the energy autonomous source is 5 kg, HE-charge mass is 100 g. Several variants of magnetic systems were tested. Comparison of the magneto-cumulative generator operation, powered from permanent magnets and powered from capacitor bank was carried out. Optimizing the magnetic system with numerical methods the authors managed to get almost identical distribution of the fields in the generators. Finally, the generator based on permanent magnets operates and provides similar output characteristics as the generator powered from the capacitor bank. In contrast to other magneto-cumulative energy sources powered, for example, from an accumulator or piezo-generator, this source, based on permanent magnets, has higher specific energy characteristics, does not require any switching elements and always ready for operation.

  18. El Carreto o Cumulá - Aspidosperma Dugandii Standl El Carreto o Cumulá - Aspidosperma Dugandii Standl

    Directory of Open Access Journals (Sweden)

    Dugand Armando

    1944-03-01

    Full Text Available Nombres vulgares: Carreto (Atlántico, Bolívar, Magdalena; Cumulá, Cumulá (Cundinamarca, ToIima. Según el Dr. Emilio Robledo (Lecciones de Bot. ed. 3, 2: 544. 1939 el nombre Carreto también es empleado en Puerto Berrío (Antioquia. El mismo autor (loc. cit. da el nombre Comulá para una especie indeterminada de Viburnum en Mariquita (Tolima y J. M. Duque, refiriendose a la misma planta y localidad (en Bot. Gen. Colomb. 340, 356. 1943 atribuye este nombre vulgar al Aspidosperma ellipticum Rusby.  Sin embargo, las muestras de madera de Cumulá o Comulá que yo he examinado, procedentes de la región de Mariquita -una de las cuales me fue recientemente enviada por el distinguido ictiólogo Sr. Cecil Miles- pertenecen sin duda alguna al A. Dugandii StandI. Por otra parte, Santiago Cortés (FI. Colomb. 206. 1898; ed, 2: 239. 1912 cita el Cumulá "de Anapoima y otros lugares del (rio Magdalena" diciendo que pertenece a las Leguminosas, pero la brevísima descripción que este autor hace de la madera "naranjada y notable por densidad, dureza y resistencia a la humedad", me induce a creer que se trata del mismo Cumula coleccionado recientemente en Tocaima, ya que esta población esta situada a pocos kilómetros de Anapoima. Nombres vulgares: Carreto (Atlántico, Bolívar, Magdalena; Cumulá, Cumulá (Cundinamarca, ToIima. Según el Dr. Emilio Robledo (Lecciones de Bot. ed. 3, 2: 544. 1939 el nombre Carreto también es empleado en Puerto Berrío (Antioquia. El mismo autor (loc. cit. da el nombre Comulá para una especie indeterminada de Viburnum en Mariquita (Tolima y J. M. Duque, refiriendose a la misma planta y localidad (en Bot. Gen. Colomb. 340, 356. 1943 atribuye este nombre vulgar al Aspidosperma ellipticum Rusby.  Sin embargo, las muestras de madera de Cumulá o Comulá que yo he examinado, procedentes de la región de Mariquita -una de las cuales me fue recientemente enviada por el distinguido ictiólogo Sr. Cecil Miles- pertenecen sin

  19. Predictive value of neurological examination for early cortical responses to somatosensory evoked potentials in patients with postanoxic coma

    NARCIS (Netherlands)

    Bouwes, A.; Binnekade, J.M.; Verbaan, B.W.; Zandbergen, E.G.J.; Koelman, J.H.T.M.; Weinstein, H.C.; Hijdra, A.; van Horn, J.

    2012-01-01

    Bilateral absence of cortical N20 responses of median nerve somatosensory evoked potentials (SEP) predicts poor neurological outcome in postanoxic coma after cardiopulmonary resuscitation (CPR). Although SEP is easy to perform and available in most hospitals, it is worthwhile to know how

  20. Functional MRI activation of somatosensory and motor cortices in a hand-grafted patient with early clinical sensorimotor recovery

    International Nuclear Information System (INIS)

    Neugroschl, C.; Denolin, V.; Schuind, F.; Holder, C. van; David, P.; Baleriaux, D.; Metens, T.

    2005-01-01

    The aim of this study was to investigate somatosensory and motor cortical activity with functional MRI (fMRI) in a hand-grafted patient with early clinical recovery. The patient had motor fMRI examinations before transplantation, and motor and passive tactile stimulations after surgery. His normal hand and a normal group were studied for comparison. A patient with complete brachial plexus palsy was studied to assess the lack of a fMRI signal in somatosensory areas in the case of total axonal disconnection. Stimulating the grafted hand revealed significant activation in the contralateral somatosensory cortical areas in all fMRI examinations. The activation was seen as early as 10 days after surgery; this effect cannot be explained by the known physiological mechanisms of nerve regeneration. Although an imagination effect cannot be excluded, the objective clinical recovery of sensory function led us to formulate the hypothesis that a connection to the somatosensory cortex was rapidly established. Additional cases and fundamental studies are needed to assess this hypothesis, but several observations were compatible with this explanation. Before surgery, imaginary motion of the amputated hand produced less intense responses than executed movements of the intact hand, whereas the normal activation pattern for right-handed subjects was found after surgery, in agreement with the good clinical motor recovery. (orig.)

  1. Rapid stimulus-evoked astrocyte Ca2+ elevations and hemodynamic responses in mouse somatosensory cortex in vivo

    DEFF Research Database (Denmark)

    Lind, Barbara Lykke; Brazhe, Alexey; Jessen, Sanne Barsballe

    2013-01-01

    +) elevations with rapid onset and short duration in a large proportion of cortical astrocytes in the adult mouse somatosensory cortex. Our improved detection of the fast Ca(2+) signals is due to a signal-enhancing analysis of the Ca(2+) activity. The rapid stimulation-evoked Ca(2+) increases identified...

  2. Cortical control of generalized absence seizures: effects of lidocaine applied to the somatosensory cortex in wag/rij rats

    NARCIS (Netherlands)

    Sitnikova, E.Y.; Luijtelaar, E.L.J.M. van; Luijtelaar, E.L.J.M. van; Kuznetsova, G.D.; Coenen, A.M.L.; Chepurnov, S.A.

    2004-01-01

    In the WAG/Rij rat strain, a genetic model of absence epilepsy, generalized spike-wave discharges (SWDs) are initiated in a specific area of the somatosensory cortex and quickly spread over the cortex and thalamus. This cortical focus regarded as a "leading" spot, driving SWDs (Meeren et al., J.

  3. Functional MRI activation of somatosensory and motor cortices in a hand-grafted patient with early clinical sensorimotor recovery

    Energy Technology Data Exchange (ETDEWEB)

    Neugroschl, C.; Denolin, V.; Schuind, F.; Holder, C. van; David, P.; Baleriaux, D.; Metens, T. [ULB-Hopital Erasme, Radiology, Brussels (Belgium)

    2005-09-01

    The aim of this study was to investigate somatosensory and motor cortical activity with functional MRI (fMRI) in a hand-grafted patient with early clinical recovery. The patient had motor fMRI examinations before transplantation, and motor and passive tactile stimulations after surgery. His normal hand and a normal group were studied for comparison. A patient with complete brachial plexus palsy was studied to assess the lack of a fMRI signal in somatosensory areas in the case of total axonal disconnection. Stimulating the grafted hand revealed significant activation in the contralateral somatosensory cortical areas in all fMRI examinations. The activation was seen as early as 10 days after surgery; this effect cannot be explained by the known physiological mechanisms of nerve regeneration. Although an imagination effect cannot be excluded, the objective clinical recovery of sensory function led us to formulate the hypothesis that a connection to the somatosensory cortex was rapidly established. Additional cases and fundamental studies are needed to assess this hypothesis, but several observations were compatible with this explanation. Before surgery, imaginary motion of the amputated hand produced less intense responses than executed movements of the intact hand, whereas the normal activation pattern for right-handed subjects was found after surgery, in agreement with the good clinical motor recovery. (orig.)

  4. Visual Responsiveness of Neurons in the Secondary Somatosensory Area and its Surrounding Parietal Operculum Regions in Awake Macaque Monkeys

    Science.gov (United States)

    Hihara, Sayaka; Taoka, Miki; Tanaka, Michio; Iriki, Atsushi

    2015-01-01

    Previous neurophysiological studies performed in macaque monkeys have shown that the secondary somatosensory cortex (SII) is essentially engaged in the processing of somatosensory information and no other sensory input has been reported. In contrast, recent human brain-imaging studies have revealed the effects of visual and auditory stimuli on SII activity, which suggest multisensory integration in the human SII. To determine whether multisensory responses of the SII also exist in nonhuman primates, we recorded single-unit activity in response to visual and auditory stimuli from the SII and surrounding regions in 8 hemispheres from 6 awake monkeys. Among 1157 recorded neurons, 306 neurons responded to visual stimuli. These visual neurons usually responded to rather complex stimuli, such as stimulation of the peripersonal space (40.5%), observation of human action (29.1%), and moving-object stimulation outside the monkey's reach (23.9%). We occasionally applied auditory stimuli to visual neurons and found 10 auditory-responsive neurons that exhibited somatosensory responses. The visual neurons were distributed continuously along the lateral sulcus covering the entire SII, along with other somatosensory neurons. These results highlight the need to investigate novel functional roles—other than somesthetic sensory processing—of the SII. PMID:25962920

  5. Stimulation of dural vessels excites the SI somatosensory cortex of the cat via a relay in the thalamus.

    Science.gov (United States)

    Lambert, Geoffrey A; Hoskin, Karen L; Michalicek, Jan; Panahi, Seyed E; Truong, Linda; Zagami, Alessandro S

    2014-04-01

    We carried out experiments in cats to determine the thalamo-cortical projection sites of trigeminovascular sensory neurons. 1) We stimulated the middle meningeal artery (MMA) with C-fibre intensity electrical shocks and made field potential recordings over the somatosensory cortical surface. 2) We then recorded neurons in the ventroposteromedial (VPM) nucleus of the thalamus in search of neurons which could be activated from the skin, MMA and superior sagittal sinus. 3) Finally, we attempted to antidromically activate the neurons found in stage 2 by stimulating the responsive cortical areas revealed in stage 1. VPM neurons received trigeminovascular input, input from the V1 facial skin and could also be activated by electrical stimulation of the somatosensory cortex. VPM neurons activated from the cortex responded with short and invariant latencies (6.7 ± 7.7 msec mean and SD). They could follow high rates of stimulation and sometimes showed collision with orthodromic action potentials. We conclude that somatosensory (SI) cortical stimulation excites trigeminovascular VPM neurons antidromically. In consequence, these VPM neurons project to the somatosensory cortex. These findings may help to explain the ability of migraineurs with headache in the trigeminal distribution to localise their pain to a particular region in this distribution.

  6. Primary somatosensory contribution to action observation brain activity-combining fMRI and cTBS

    NARCIS (Netherlands)

    Valchev, Nikola; Gazzola, Valeria; Avenanti, Alessio; Keysers, Christian

    Traditionally the mirror neuron system (MNS) only includes premotor and posterior parietal cortices. However, somatosensory cortices, BA1/2 in particular, are also activated during action execution and observation. Here, we examine whether BA1/2 and the parietofrontal MNS integrate information by

  7. Do patients with chronic patellar tendinopathy have an altered somatosensory profile? A Quantitative Sensory Testing (QST) study

    NARCIS (Netherlands)

    van Wilgen, C. P.; Konopka, K. H.; Keizer, D.; Zwerver, J.; Dekker, R.

    The prevalence of tendinopathies in sports is high. The etiology and pain mechanisms of tendinopathies are not completely understood. Currently, little is known whether, or to which degree, somatosensory changes within the nervous system may contribute to the pain in tendinopathies. We conducted a

  8. GABAA receptor in the thalamic specific relay system contributes to the propofol-induced somatosensory cortical suppression in rat.

    Science.gov (United States)

    Zhang, Yu; Wang, Chaoping; Zhang, Yi; Zhang, Lin; Yu, Tian

    2013-01-01

    Interaction with the gamma-aminobutyric-acid-type-A (GABAA) receptors is recognized as an important component of the mechanism of propofol, a sedative-hypnotic drug commonly used as anesthetic. However the contribution of GABAA receptors to the central nervous system suppression is still not well understood, especially in the thalamocortical network. In the present study, we investigated if intracerebral injection of bicuculline (a GABAA receptor antagonist) into the thalamus ventral posteromedial nucleus (VPM, a thalamus specific relay nuclei that innervated S1 mostly) could reverse propofol-induced cortical suppression, through recording the changes of both spontaneous and somatosensory neural activities in rat's somatosensory cortex (S1). We found that after injection of bicuculline into VPM, significant increase of neural activities were observed in all bands of local field potentials (total band, 182±6%), while the amplitude of all components in somatosensory evoked potentials were also increased (negative, 121±9% and positive, 124±6%).These data support that the potentiation of GABAA receptor-mediated synaptic inhibition in a thalamic specific relay system seems to play a crucial role in propofol-induced cortical suppression in the somatosensory cortex of rats.

  9. Multimodal and widespread somatosensory abnormalities in persistent shoulder pain in the first 6 months efter stroke: An exploratory study

    NARCIS (Netherlands)

    Roosink, M.; van Dongen, Robert T.; Buitenweg, Jan R.; Renzenbrink, Gerbert J.; Geurts, Alexander C.; IJzerman, Maarten Joost

    2012-01-01

    Objective: To explore the role of multimodal and widespread somatosensory abnormalities in the development of persistent poststroke shoulder pain (pPSSP) in the first 6 months after stroke. Design: Prospective inception cohort study. Setting: Stroke units of 2 teaching hospitals. Participants: The

  10. Detection of optogenetic stimulation in somatosensory cortex by non-human primates--towards artificial tactile sensation.

    Science.gov (United States)

    May, Travis; Ozden, Ilker; Brush, Benjamin; Borton, David; Wagner, Fabien; Agha, Naubahar; Sheinberg, David L; Nurmikko, Arto V

    2014-01-01

    Neuroprosthesis research aims to enable communication between the brain and external assistive devices while restoring lost functionality such as occurs from stroke, spinal cord injury or neurodegenerative diseases. In future closed-loop sensorimotor prostheses, one approach is to use neuromodulation as direct stimulus to the brain to compensate for a lost sensory function and help the brain to integrate relevant information for commanding external devices via, e.g. movement intention. Current neuromodulation techniques rely mainly of electrical stimulation. Here we focus specifically on the question of eliciting a biomimetically relevant sense of touch by direct stimulus of the somatosensory cortex by introducing optogenetic techniques as an alternative to electrical stimulation. We demonstrate that light activated opsins can be introduced to target neurons in the somatosensory cortex of non-human primates and be optically activated to create a reliably detected sensation which the animal learns to interpret as a tactile sensation localized within the hand. The accomplishment highlighted here shows how optical stimulation of a relatively small group of mostly excitatory somatosensory neurons in the nonhuman primate brain is sufficient for eliciting a useful sensation from data acquired by simultaneous electrophysiology and from behavioral metrics. In this first report to date on optically neuromodulated behavior in the somatosensory cortex of nonhuman primates we do not yet dissect the details of the sensation the animals exerience or contrast it to those evoked by electrical stimulation, issues of considerable future interest.

  11. Detection of optogenetic stimulation in somatosensory cortex by non-human primates--towards artificial tactile sensation.

    Directory of Open Access Journals (Sweden)

    Travis May

    Full Text Available Neuroprosthesis research aims to enable communication between the brain and external assistive devices while restoring lost functionality such as occurs from stroke, spinal cord injury or neurodegenerative diseases. In future closed-loop sensorimotor prostheses, one approach is to use neuromodulation as direct stimulus to the brain to compensate for a lost sensory function and help the brain to integrate relevant information for commanding external devices via, e.g. movement intention. Current neuromodulation techniques rely mainly of electrical stimulation. Here we focus specifically on the question of eliciting a biomimetically relevant sense of touch by direct stimulus of the somatosensory cortex by introducing optogenetic techniques as an alternative to electrical stimulation. We demonstrate that light activated opsins can be introduced to target neurons in the somatosensory cortex of non-human primates and be optically activated to create a reliably detected sensation which the animal learns to interpret as a tactile sensation localized within the hand. The accomplishment highlighted here shows how optical stimulation of a relatively small group of mostly excitatory somatosensory neurons in the nonhuman primate brain is sufficient for eliciting a useful sensation from data acquired by simultaneous electrophysiology and from behavioral metrics. In this first report to date on optically neuromodulated behavior in the somatosensory cortex of nonhuman primates we do not yet dissect the details of the sensation the animals exerience or contrast it to those evoked by electrical stimulation, issues of considerable future interest.

  12. Effects of Improvement on Selective Attention: Developing Appropriate Somatosensory Video Game Interventions for Institutional-Dwelling Elderly with Disabilities

    Science.gov (United States)

    Chen, Shang-Ti; Chiang, I-Tsun; Liu, Eric Zhi-Feng; Chang, Maiga

    2012-01-01

    The purpose of this study was to develop appropriate somatosensory video game interventions on enhancing selective attention of institutional-dwelling elderly with disabilities. Fifty-eight participants aged 65[approximately]92 were recruited and divided into four groups, 4-week and 8-week experimental and two control groups, for evaluating the…

  13. Somatosensory BOLD fMRI reveals close link between salient blood pressure changes and the murine neuromatrix.

    Science.gov (United States)

    Reimann, Henning Matthias; Todiras, Mihail; Hodge, Russ; Huelnhagen, Till; Millward, Jason Michael; Turner, Robert; Seeliger, Erdmann; Bader, Michael; Pohlmann, Andreas; Niendorf, Thoralf

    2018-05-15

    The neuromatrix, or "pain matrix", is a network of cortical brain areas which is activated by noxious as well as salient somatosensory stimulation. This has been studied in mice and humans using blood oxygenation level-dependent (BOLD) fMRI. Here we demonstrate that BOLD effects observed in the murine neuromatrix in response to salient somatosensory stimuli are prone to reflect mean arterial blood pressure (MABP) changes, rather than neural activity. We show that a standard electrostimulus typically used in murine somatosensory fMRI can induce substantial elevations in MABP. Equivalent drug-induced MABP changes - without somatosensory stimulation - evoked BOLD patterns in the neuromatrix strikingly similar to those evoked by electrostimulation. This constitutes a serious caveat for murine fMRI. The regional specificity of these BOLD patterns can be attributed to the co-localization of the neuromatrix with large draining veins. Based on these findings we propose a cardiovascular support mechanism whereby abrupt elevations in MABP provide additional energy supply to the neuromatrix and other essential brain areas in fight-or-flight situations. Copyright © 2018 Elsevier Inc. All rights reserved.

  14. Determining source cumulants in femtoscopy with Gram-Charlier and Edgeworth series

    DEFF Research Database (Denmark)

    Eggers, H. C.; De Kock, M. B.; Schmiegel, Jürgen

    2011-01-01

    Lowest-order cumulants provide important information on the shape of the emission source in femtoscopy. For the simple case of noninteracting identical particles, we show how the fourth-order source cumulant can be determined from measured cumulants in momentum space. The textbook Gram–Charlier s......Lowest-order cumulants provide important information on the shape of the emission source in femtoscopy. For the simple case of noninteracting identical particles, we show how the fourth-order source cumulant can be determined from measured cumulants in momentum space. The textbook Gram...

  15. Determining source cumulants in femtoscopy with Gram-Charlier and Edgeworth series

    DEFF Research Database (Denmark)

    Schmiegel, Jürgen; Eggers, Hans C.; de Kock, Michiel B

    Lowest-order cumulants provide important information on the shape of the emission source in femtoscopy. For the simple case of noninteracting identical particles, we show how the fourth-order source cumulant can be determined from measured cumulants in momentum space. The textbook Gram-Charlier s......Lowest-order cumulants provide important information on the shape of the emission source in femtoscopy. For the simple case of noninteracting identical particles, we show how the fourth-order source cumulant can be determined from measured cumulants in momentum space. The textbook Gram...

  16. Childhood Psychosocial Cumulative Risks and Carotid Intima-Media Thickness in Adulthood: The Cardiovascular Risk in Young Finns Study.

    Science.gov (United States)

    Hakulinen, Christian; Pulkki-Råback, Laura; Elovainio, Marko; Kubzansky, Laura D; Jokela, Markus; Hintsanen, Mirka; Juonala, Markus; Kivimäki, Mika; Josefsson, Kim; Hutri-Kähönen, Nina; Kähönen, Mika; Viikari, Jorma; Keltikangas-Järvinen, Liisa; Raitakari, Olli T

    2016-01-01

    Adverse experiences in childhood may influence cardiovascular risk in adulthood. We examined the prospective associations between types of psychosocial adversity and having multiple adversities (e.g., cumulative risk) with carotid intima-media thickness (IMT) and its progression among young adults. Higher cumulative risk score in childhood was expected to be associated with higher IMT and its progression. Participants were 2265 men and women (age range, 24-39 years in 2001) from the ongoing Cardiovascular Risk in Young Finns study whose carotid IMTs were measured in 2001 and 2007. A cumulative psychosocial risk score, assessed at the study baseline in 1980, was derived from four separate aspects of the childhood environment that may impose risk (childhood stressful life events, parental health behavior family, socioeconomic status, and childhood emotional environment). The cumulative risk score was associated with higher IMT in 2007 (b = 0.004, standard error [SE] = 0.001, p risk factors in childhood and adulthood, including adulthood health behavior, adulthood socioeconomic status, and depressive symptoms. Among the individual childhood psychosocial risk categories, having more stressful life events was associated with higher IMT in 2001 (b = 0.007, SE = 0.003, p = .016) and poorer parental health behavior predicted higher IMT in 2007 (b = 0.004, SE = 0.002, p = .031) after adjustment for age, sex, and childhood cardiovascular risk factors. Early life psychosocial environment influences cardiovascular risk later in life, and considering cumulative childhood risk factors may be more informative than individual factors in predicting progression of preclinical atherosclerosis in adulthood.

  17. Co-occurrence of Pain Symptoms and Somatosensory Sensitivity in Burning Mouth Syndrome: A Systematic Review.

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    Xavier Moisset

    Full Text Available Burning mouth syndrome (BMS is a chronic and spontaneous oral pain with burning quality in the tongue or other oral mucosa without any identifiable oral lesion or laboratory finding. Pathogenesis and etiology of BMS are still unknown. However, BMS has been associated with other chronic pain syndromes including other idiopathic orofacial pain, the dynias group and the family of central sensitivity syndromes. This would imply that BMS shares common mechanisms with other cephalic and/or extracephalic chronic pains. The primary aim of this systematic review was to determine whether BMS is actually associated with other pain syndromes, and to analyze cephalic and extracephalic somatosensory sensitivity in these patients.This report followed the PRISMA Statement. An electronic search was performed until January 2015 in PubMed, Cochrane library, Wiley and ScienceDirect. Searched terms included "burning mouth syndrome OR stomatodynia OR glossodynia OR burning tongue OR oral burning". Studies were selected according to predefined inclusion criteria (report of an association between BMS and other pain(s symptoms or of cutaneous cephalic and/or extracephalic quantitative sensory testing in BMS patients, and a descriptive analysis conducted.The search retrieved 1512 reports. Out of these, twelve articles met criteria for co-occurring pain symptoms and nine studies for quantitative sensory testing (QST in BMS patients. The analysis reveals that in BMS patients co-occurring pain symptoms are rare, assessed by only 0.8% (12 of 1512 of the retrieved studies. BMS was associated with headaches, TMD, atypical facial pain, trigeminal neuralgia, post-herpetic facial pain, back pain, fibromyalgia, joint pain, abdominal pain, rectal pain or vulvodynia. However, the prevalence of pain symptoms in BMS patients is not different from that in the age-matched general population. QST studies reveal no or inconsistent evidence of abnormal cutaneous cephalic and extracephalic

  18. Calmodulin Methyltransferase Is Required for Growth, Muscle Strength, Somatosensory Development and Brain Function.

    Science.gov (United States)

    Haziza, Sitvanit; Magnani, Roberta; Lan, Dima; Keinan, Omer; Saada, Ann; Hershkovitz, Eli; Yanay, Nurit; Cohen, Yoram; Nevo, Yoram; Houtz, Robert L; Sheffield, Val C; Golan, Hava; Parvari, Ruti

    2015-08-01

    Calmodulin lysine methyl transferase (CaM KMT) is ubiquitously expressed and highly conserved from plants to vertebrates. CaM is frequently trimethylated at Lys-115, however, the role of CaM methylation in vertebrates has not been studied. CaM KMT was found to be homozygously deleted in the 2P21 deletion syndrome that includes 4 genes. These patients present with cystinuria, severe intellectual disabilities, hypotonia, mitochondrial disease and facial dysmorphism. Two siblings with deletion of three of the genes included in the 2P21 deletion syndrome presented with cystinuria, hypotonia, a mild/moderate mental retardation and a respiratory chain complex IV deficiency. To be able to attribute the functional significance of the methylation of CaM in the mouse and the contribution of CaM KMT to the clinical presentation of the 2p21deletion patients, we produced a mouse model lacking only CaM KMT with deletion borders as in the human 2p21deletion syndrome. No compensatory activity for CaM methylation was found. Impairment of complexes I and IV, and less significantly III, of the mitochondrial respiratory chain was more pronounced in the brain than in muscle. CaM KMT is essential for normal body growth and somatosensory development, as well as for the proper functioning of the adult mouse brain. Developmental delay was demonstrated for somatosensory function and for complex behavior, which involved both basal motor function and motivation. The mutant mice also had deficits in motor learning, complex coordination and learning of aversive stimuli. The mouse model contributes to the evaluation of the role of methylated CaM. CaM methylation appears to have a role in growth, muscle strength, somatosensory development and brain function. The current study has clinical implications for human patients. Patients presenting slow growth and muscle weakness that could result from a mitochondrial impairment and mental retardation should be considered for sequence analysis of the Ca

  19. Pain affect in the absence of pain sensation: evidence of asomaesthesia after somatosensory cortex lesions in the rat.

    Science.gov (United States)

    Uhelski, Megan L; Davis, Matthew A; Fuchs, Perry N

    2012-04-01

    Multidimensional models of pain processing distinguish the sensory, motivational, and affective components of the pain experience. Efforts to understand underlying mechanisms have focused on isolating the roles of specific brain structures, including both limbic and non-limbic cortical areas, in the processing of nociceptive stimuli. The purpose of this study was to examine the role of the somatosensory cortex in both sensory and affective aspects of pain processing. It was hypothesized that animals with lesions of the hind limb area of the somatosensory cortex would demonstrate altered sensory processing (asomaesthesia, a deficit in the ability to detect and identify somatic sensation) in the presence of an inflammatory state when compared to animals with sham lesions. The level of pain affect produced by an inflammatory pain condition was not expected to change, as this region has not demonstrated a role in processing the affective component of pain. Seventy-nine adult female Sprague-Dawley rats were randomly assigned to receive bilateral lesions or a sham procedure. The results showed that somatosensory lesions to the hindlimb region altered responses to mechanical stimulation in the presence of experimentally-induced inflammation, but did not attenuate the inflammation-induced paw volume changes or the level of pain affect, as demonstrated by escape/avoidance behavior in response to mechanical stimulation. Overall, these results support previous evidence suggesting that the somatosensory cortex is primarily involved in the processing the sensory/discriminative aspect of pain, and