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Ben Godde - One of the best experts on this subject based on the ideXlab platform.
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a parietal to frontal shift in the p300 is associated with compensation of Tactile Discrimination deficits in late middle aged adults
Psychophysiology, 2013Co-Authors: Evamaria Reuter, Claudia Voelckerrehage, Solveig Vieluf, Axel H Winneke, Ben GoddeAbstract:Tactile perception declines with age on both behavioral and neurophysiological levels. Less well understood is how neurophysiological changes relate to Tactile Discrimination performance in middle adulthood. A Tactile Discrimination task was conducted while ERPs were measured in three groups of healthy adults aged 20 to 66 years. Accuracy was lowest in late middle adulthood (56-66 years) while somatosensory ERP components (P50, N70, P100, N140) were comparable across age groups. The cognitive P300 revealed age-related differences in scalp distribution typical for older adults to already be present in late middle adulthood. Increased recruitment of frontal cognitive processes was positively related to performance in later middle adulthood. Our results further the understanding of age-related differences in Tactile perception during middle adulthood and the importance of cognitive processes to compensate for age-related decline. Copyright
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A parietal‐to‐frontal shift in the P300 is associated with compensation of Tactile Discrimination deficits in late middle‐aged adults
Psychophysiology, 2013Co-Authors: Evamaria Reuter, Solveig Vieluf, Axel H Winneke, Claudia Voelcker-rehage, Ben GoddeAbstract:Tactile perception declines with age on both behavioral and neurophysiological levels. Less well understood is how neurophysiological changes relate to Tactile Discrimination performance in middle adulthood. A Tactile Discrimination task was conducted while ERPs were measured in three groups of healthy adults aged 20 to 66 years. Accuracy was lowest in late middle adulthood (56-66 years) while somatosensory ERP components (P50, N70, P100, N140) were comparable across age groups. The cognitive P300 revealed age-related differences in scalp distribution typical for older adults to already be present in late middle adulthood. Increased recruitment of frontal cognitive processes was positively related to performance in later middle adulthood. Our results further the understanding of age-related differences in Tactile perception during middle adulthood and the importance of cognitive processes to compensate for age-related decline. Copyright
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Facilitating Effect of 15-Hz Repetitive Transcranial Magnetic Stimulation on Tactile Perceptual Learning
Journal of Cognitive Neuroscience, 2006Co-Authors: Ahmed A Karim, Anne Schüler, Yiwen Li Hegner, Eva Friedel, Ben GoddeAbstract:Recent neuroimaging studies have revealed that Tactile perceptual learning can lead to substantial reorganizational changes of the brain. We report here for the first time that combining high-frequency (15 Hz) repetitive transcranial magnetic stimulation (rTMS) over the primary somatosensory cortex (SI) with Tactile Discrimination training is capable of facilitating operant perceptual learning. Most notably, increasing the excitability of SI by 15-Hz rTMS improved perceptual learning in spatial, but not in temporal, Discrimination tasks. These findings give causal support to recent correlative data obtained by functional magnetic resonance imaging studies indicating a differential role of SI in spatial and temporal Discrimination learning. The introduced combination of rTMS and Tactile Discrimination training may provide new therapeutical potentials in facilitating neuropsychological rehabilitation of functional deficits after lesions of the somatosensory cortex.
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improvement and decline in Tactile Discrimination behavior after cortical plasticity induced by passive Tactile coactivation
The Journal of Neuroscience, 2004Co-Authors: Amra Hodzic, Ralf Veit, Ahmed A Karim, Ben GoddeAbstract:Perceptual learning can be induced by passive Tactile coactivation without attention or reinforcement. We used functional MRI (fMRI) and psychophysics to investigate in detail the specificity of this type of learning for different Tactile Discrimination tasks and the underlying cortical reorganization. We found that a few hours of Hebbian coactivation evoked a significant increase of primary (SI) and secondary (SII) somatosensory cortical areas representing the stimulated body parts. The amount of plastic changes was strongly correlated with improvement in spatial Discrimination performance. However, in the same subjects, frequency Discrimination was impaired after coactivation, indicating that even maladaptive processes can be induced by intense passive sensory stimulation.
Miguel A L Nicolelis - One of the best experts on this subject based on the ideXlab platform.
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frequency specific coupling in fronto parieto occipital cortical circuits underlie active Tactile Discrimination
Scientific Reports, 2019Co-Authors: Carolina Kunicki, Renan C Moioli, Miguel Paisvieira, Andre Salles Cunha Peres, Edgard Morya, Miguel A L NicolelisAbstract:Processing of Tactile sensory information in rodents is critically dependent on the communication between the primary somatosensory cortex (S1) and higher-order integrative cortical areas. Here, we have simultaneously characterized single-unit activity and local field potential (LFP) dynamics in the S1, primary visual cortex (V1), anterior cingulate cortex (ACC), posterior parietal cortex (PPC), while freely moving rats performed an active Tactile Discrimination task. Simultaneous single unit recordings from all these cortical regions revealed statistically significant neuronal firing rate modulations during all task phases (anticipatory, Discrimination, response, and reward). Meanwhile, phase analysis of pairwise LFP recordings revealed the occurrence of long-range synchronization across the sampled fronto-parieto-occipital cortical areas during Tactile sampling. Causal analysis of the same pairwise recorded LFPs demonstrated the occurrence of complex dynamic interactions between cortical areas throughout the fronto-parietal-occipital loop. These interactions changed significantly between cortical regions as a function of frequencies (i.e. beta, theta and gamma) and according to the different phases of the behavioral task. Overall, these findings indicate that active Tactile Discrimination by rats is characterized by much more widespread and dynamic complex interactions within the fronto-parieto-occipital cortex than previously anticipated.
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cortical and thalamic contributions to response dynamics across layers of the primary somatosensory cortex during Tactile Discrimination
Journal of Neurophysiology, 2015Co-Authors: Miguel Paisvieira, Carolina Kunicki, Pohe Tseng, Joel R Martin, Mikhail A Lebedev, Miguel A L NicolelisAbstract:Tactile information processing in the rodent primary somatosensory cortex (S1) is layer specific and involves modulations from both thalamocortical and cortico-cortical loops. However, the extent to which these loops influence the dynamics of the primary somatosensory cortex while animals execute Tactile Discrimination remains largely unknown. Here, we describe neural dynamics of S1 layers across the multiple epochs defining a Tactile Discrimination task. We observed that neuronal ensembles within different layers of the S1 cortex exhibited significantly distinct neurophysiological properties, which constantly changed across the behavioral states that defined a Tactile Discrimination. Neural dynamics present in supragranular and granular layers generally matched the patterns observed in the ventral posterior medial nucleus of the thalamus (VPM), whereas the neural dynamics recorded from infragranular layers generally matched the patterns from the posterior nucleus of the thalamus (POM). Selective inactivation of contralateral S1 specifically switched infragranular neural dynamics from POM-like to those resembling VPM neurons. Meanwhile, ipsilateral M1 inactivation profoundly modulated the firing suppression observed in infragranular layers. This latter effect was counterbalanced by contralateral S1 block. Tactile stimulus encoding was layer specific and selectively affected by M1 or contralateral S1 inactivation. Lastly, causal information transfer occurred between all neurons in all S1 layers but was maximal from infragranular to the granular layer. These results suggest that Tactile information processing in the S1 of awake behaving rodents is layer specific and state dependent and that its dynamics depend on the asynchronous convergence of modulations originating from ipsilateral M1 and contralateral S1.
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basal forebrain dynamics during a Tactile Discrimination task
Journal of Neurophysiology, 2014Co-Authors: Kathryn Sylvester, Eric E Thomson, Annie Mcdonough, Stefani Tica, Miguel A L NicolelisAbstract:The nucleus basalis (NB) is a cholinergic neuromodulatory structure that projects liberally to the entire cortical mantle and regulates information processing in all cortical layers. Here, we recorded activity from populations of single units in the NB as rats performed a whisker-dependent Tactile Discrimination task. Over 80% of neurons responded with significant modulation in at least one phase of the task. Such activity started before stimulus onset and continued for seconds after reward delivery. Firing rates monotonically increased with reward magnitude during the task, suggesting that NB neurons are not indicating the absolute deviation from expected reward amounts. Individual neurons also encoded significant amounts of information about stimulus identity. Such robust coding was not present when the same stimuli were delivered to lightly anesthetized animals, suggesting that the NB neurons contain a sensorimotor, rather than purely sensory or motor, representation of the environment. Overall, these results support the hypothesis that neurons in the NB provide a value-laden representation of the sensorimotor state of the animal as it engages in significant behavioral tasks.
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changes in s1 neural responses during Tactile Discrimination learning
Journal of Neurophysiology, 2010Co-Authors: Michael C Wiest, Eric E Thomson, Janaina Pantoja, Miguel A L NicolelisAbstract:In freely moving rats that are actively performing a Discrimination task, single-unit responses in primary somatosensory cortex (S1) are strikingly different from responses to comparable Tactile stimuli in immobile rats. For example, in the active Discrimination context prestimulus response modulations are common, responses are longer in duration and more likely to be inhibited. To determine whether these differences emerge as rats learned a whisker-dependent Discrimination task, we recorded single-unit S1 activity while rats learned to discriminate aperture-widths using their whiskers. Even before Discrimination training began, S1 responses in freely moving rats showed many of the signatures of active responses, such as increased duration of response and prestimulus response modulations. As rats subsequently learned the Discrimination task, single unit responses changed: more cortical units responded to the stimuli, neuronal sensory responses grew in duration, and individual neurons better predicted aperture-width. In summary, the operant behavioral context changes S1 Tactile responses even in the absence of Tactile Discrimination, whereas subsequent width Discrimination learning refines the S1 representation of aperture-width.
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neuronal activity in the primary somatosensory thalamocortical loop is modulated by reward contingency during Tactile Discrimination
The Journal of Neuroscience, 2007Co-Authors: Janaina Pantoja, Michael C Wiest, Sidarta Ribeiro, Ernesto S Soares, Damien Gervasoni, Nelson A M Lemos, Miguel A L NicolelisAbstract:Delayed-response sensory Discrimination is believed to require primary sensory thalamus and cortex for early stimulus identification and higher-order forebrain regions for the late association of stimuli with rewarded motor responses. Here we investigate neuronal responses in the rat primary somatosensory cortex (S1) and ventral posterior medial nucleus of the thalamus (VPM) during a Tactile Discrimination task that requires animals to associate two different Tactile stimuli with two corresponding choices of spatial trajectory to be rewarded. To manipulate reward expectation, neuronal activity observed under regular reward contingency (CR) was compared with neuronal activity recorded during freely rewarded (FR) trials, in which animals obtained reward regardless of their choice of spatial trajectory. Across-trial firing rates of S1 and VPM neurons varied according to the reward contingency of the task. Analysis of neuronal ensemble activity by an artificial neural network showed that stimulus-related information in S1 and VPM increased from stimulus sampling to reward delivery in CR trials but decreased to chance levels when animals performed FR trials, when stimulus Discrimination was irrelevant for task execution. Neuronal ensemble activity in VPM was only correlated with task performance during stimulus presentation. In contrast, S1 neuronal activity was highly correlated with task performance long after stimulus removal, a relationship that peaked during the 300 ms that preceded reward delivery. Together, our results indicate that neuronal activity in the primary somatosensory thalamocortical loop is strongly modulated by reward contingency.
Patrick Ragert - One of the best experts on this subject based on the ideXlab platform.
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differential effects of Tactile high and low frequency stimulation on Tactile Discrimination in human subjects
BMC Neuroscience, 2008Co-Authors: Patrick Ragert, Tobias Kalisch, Barbara Bliem, S Franzkowiak, Hubert R DinseAbstract:Long-term potentiation (LTP) and long-term depression (LTD) play important roles in mediating activity-dependent changes in synaptic transmission and are believed to be crucial mechanisms underlying learning and cortical plasticity. In human subjects, however, the lack of adequate input stimuli for the induction of LTP and LTD makes it difficult to study directly the impact of such protocols on behavior. Using Tactile high- and low-frequency stimulation protocols in humans, we explored the potential of such protocols for the induction of perceptual changes. We delivered Tactile high-frequency and low-frequency stimuli (t-HFS, t-LFS) to skin sites of approximately 50 mm2 on the tip of the index finger. As assessed by 2-point Discrimination, we demonstrate that 20 minutes of t-HFS improved Tactile Discrimination, while t-LFS impaired performance. T-HFS-effects were stable for at least 24 hours whereas t-LFS-induced changes recovered faster. While t-HFS changes were spatially very specific with no changes on the neighboring fingers, impaired Tactile performance after t-LFS was also observed on the right middle-finger. A central finding was that for both t-LFS and t-HFS perceptual changes were dependent on the size of the stimulated skin area. No changes were observed when the stimulated area was very small (< 1 mm2) indicating special requirements for spatial summation. Our results demonstrate differential effects of such protocols in a frequency specific manner that might be related to LTP- and LTD-like changes in human subjects.
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patterns of cortical reorganization parallel impaired Tactile Discrimination and pain intensity in complex regional pain syndrome
NeuroImage, 2006Co-Authors: Burkhard Pleger, Patrick Ragert, Hubert R Dinse, Claudia Wilimzig, Peter Schwenkreis, A F Forster, V Nicolas, C Maier, Martin TegenthoffAbstract:In the complex regional pain syndrome (CRPS), several theories proposed the existence of pathophysiological mechanisms of central origin. Recent studies highlighted a smaller representation of the CRPS-affected hand on the primary somatosensory cortex (SI) during non-painful stimulation of the affected side. We addressed the question whether reorganizational changes can also be found in the secondary somatosensory cortex (SII). Moreover, we investigated whether cortical changes might be accompanied by perceptual changes within associated skin territories. Seventeen patients with CRPS of one upper limb without the presence of peripheral nerve injuries (type I) were subjected to functional magnetic resonance imaging (fMRI) during electrical stimulation of both index fingers (IFs) in order to assess hemodynamic signals of the IF representation in SI and SII. As a marker of Tactile perception, we tested 2-point Discrimination thresholds on the tip of both IFs. Cortical signals within SI and SII were significantly reduced contralateral to the CRPS-affected IF as compared to the ipsilateral side and to the representation of age- and sex-matched healthy controls. In parallel, Discrimination thresholds of the CRPS-affected IF were significantly higher, giving rise to an impairment of Tactile perception within the corresponding skin territory. Mean sustained, but not current pain levels were correlated with the amount of sensory impairment and the reduction in signal strength. We conclude that patterns of cortical reorganization in SI and SII seem to parallel impaired Tactile Discrimination. Furthermore, the amount of reorganization and Tactile impairment appeared to be linked to characteristics of CRPS pain.
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combination of 5 hz repetitive transcranial magnetic stimulation rtms and Tactile coactivation boosts Tactile Discrimination in humans
Neuroscience Letters, 2003Co-Authors: Patrick Ragert, Hubert R Dinse, Burkhard Pleger, Claudia Wilimzig, Elke Frombach, Peter Schwenkreis, Martin TegenthoffAbstract:A combination of 5 Hz repetitive transcranial magnetic stimulation (rTMS) over the left primary somatosensory cortex together with Tactile coactivation applied to the right index-finger representation (coac+rTMS) boosted Tactile Discrimination ability tested on the right index-finger. Applying coactivation alone caused a 0.25 mm lowering in Tactile Discrimination thresholds. In contrast, after coac+rTMS we found a significant further improvement of Discrimination thresholds in comparison to the coactivation-induced perceptual changes alone. We demonstrate that the individual further improvement after coac+rTMS depended on the effectiveness of the coactivation protocol when applied alone. Subjects, who showed little gain in Tactile performance after coactivation alone, showed the largest improvement after coac+rTMS implying that the combined application was selective for poor learners. The selective effects of coac+rTMS are discussed in respect to N-methyl-d-aspartate receptor activation.
Martin Tegenthoff - One of the best experts on this subject based on the ideXlab platform.
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patterns of cortical reorganization parallel impaired Tactile Discrimination and pain intensity in complex regional pain syndrome
NeuroImage, 2006Co-Authors: Burkhard Pleger, Patrick Ragert, Hubert R Dinse, Claudia Wilimzig, Peter Schwenkreis, A F Forster, V Nicolas, C Maier, Martin TegenthoffAbstract:In the complex regional pain syndrome (CRPS), several theories proposed the existence of pathophysiological mechanisms of central origin. Recent studies highlighted a smaller representation of the CRPS-affected hand on the primary somatosensory cortex (SI) during non-painful stimulation of the affected side. We addressed the question whether reorganizational changes can also be found in the secondary somatosensory cortex (SII). Moreover, we investigated whether cortical changes might be accompanied by perceptual changes within associated skin territories. Seventeen patients with CRPS of one upper limb without the presence of peripheral nerve injuries (type I) were subjected to functional magnetic resonance imaging (fMRI) during electrical stimulation of both index fingers (IFs) in order to assess hemodynamic signals of the IF representation in SI and SII. As a marker of Tactile perception, we tested 2-point Discrimination thresholds on the tip of both IFs. Cortical signals within SI and SII were significantly reduced contralateral to the CRPS-affected IF as compared to the ipsilateral side and to the representation of age- and sex-matched healthy controls. In parallel, Discrimination thresholds of the CRPS-affected IF were significantly higher, giving rise to an impairment of Tactile perception within the corresponding skin territory. Mean sustained, but not current pain levels were correlated with the amount of sensory impairment and the reduction in signal strength. We conclude that patterns of cortical reorganization in SI and SII seem to parallel impaired Tactile Discrimination. Furthermore, the amount of reorganization and Tactile impairment appeared to be linked to characteristics of CRPS pain.
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combination of 5 hz repetitive transcranial magnetic stimulation rtms and Tactile coactivation boosts Tactile Discrimination in humans
Neuroscience Letters, 2003Co-Authors: Patrick Ragert, Hubert R Dinse, Burkhard Pleger, Claudia Wilimzig, Elke Frombach, Peter Schwenkreis, Martin TegenthoffAbstract:A combination of 5 Hz repetitive transcranial magnetic stimulation (rTMS) over the left primary somatosensory cortex together with Tactile coactivation applied to the right index-finger representation (coac+rTMS) boosted Tactile Discrimination ability tested on the right index-finger. Applying coactivation alone caused a 0.25 mm lowering in Tactile Discrimination thresholds. In contrast, after coac+rTMS we found a significant further improvement of Discrimination thresholds in comparison to the coactivation-induced perceptual changes alone. We demonstrate that the individual further improvement after coac+rTMS depended on the effectiveness of the coactivation protocol when applied alone. Subjects, who showed little gain in Tactile performance after coactivation alone, showed the largest improvement after coac+rTMS implying that the combined application was selective for poor learners. The selective effects of coac+rTMS are discussed in respect to N-methyl-d-aspartate receptor activation.
Krish Sathian - One of the best experts on this subject based on the ideXlab platform.
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Feeling with the mind's eye: Contribution of visual cortex to Tactile perception
Behavioural Brain Research, 2002Co-Authors: Krish Sathian, Andro ZangaladzeAbstract:Visual imagery is implicated in the normal Tactile perception of certain object properties. This is an example of cross-modal interactions that characterize normal perception. Here we review recent studies from our laboratory on cross-modal interactions between vision and touch in normally sighted humans. Positron emission tomography was used to demonstrate activation of a region of extrastriate visual cortex, near the parieto-occipital fissure, during Tactile Discrimination of grating orientation. Transcranial magnetic stimulation (TMS) over this region interfered with performance of this Tactile task. In both studies, visual cortical involvement was found for Tactile Discrimination of orientation but not spatial frequency. Thus, this cortical region is not only active during but also necessary for optimal Tactile sensing of orientation. Recent findings implicating visual cortex in Braille-reading in the blind should be evaluated from this perspective. © 2002 Elsevier Science B.V. All rights reserved.
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Involvement of visual cortex in Tactile Discrimination orientation
Nature, 1999Co-Authors: Andro Zangaladze, Charles M. Epstein, Scott T Grafton, Krish SathianAbstract:The primary sense modalities (vision, touch and so on) are generally thought of as distinct. However, visual imagery is implicated in the normal Tactile perception of some object properties, such as orientation, shape and size. Furthermore, certain Tactile tasks, such as Discrimination of grating orientation and object recognition, are associated with activity in areas of visual cortex. Here we show that disrupting function of the occipital cortex using focal transcranial magnetic stimulation (TMS) interferes with the Tactile Discrimination of grating orientation. The specificity of this effect is illustrated by its time course and spatial restriction over the scalp, and by the failure of occipital TMS to affect either detection of an electrical stimulus applied to the fingerpad or Tactile Discrimination of grating texture. In contrast, TMS over the somatosensory cortex blocked Discrimination of grating texture as well as orientation. We also report that, during Tactile Discrimination of grating orientation, an evoked potential is recorded over posterior scalp regions with a latency corresponding to the peak of the TMS interference effect (about 180 ms). The findings indicate that visual cortex is closely involved in Tactile Discrimination of orientation. To our knowledge, this is the first demonstration that visual cortical processing is necessary for normal Tactile perception.