scholarly journals Analysis of haptic information in the cerebral cortex

2016 ◽  
Vol 116 (4) ◽  
pp. 1795-1806 ◽  
Author(s):  
K. Sathian
Keyword(s):  
Cerebral Cortex ◽  
Somatosensory Cortex ◽  
Visual Information ◽  
Occipital Cortex ◽  
Brain Regions ◽  
Primary Somatosensory Cortex ◽  
Intraparietal Sulcus ◽  
Haptic Information ◽  
Lateral Occipital Complex ◽  
Shape Processing

Haptic sensing of objects acquires information about a number of properties. This review summarizes current understanding about how these properties are processed in the cerebral cortex of macaques and humans. Nonnoxious somatosensory inputs, after initial processing in primary somatosensory cortex, are partially segregated into different pathways. A ventrally directed pathway carries information about surface texture into parietal opercular cortex and thence to medial occipital cortex. A dorsally directed pathway transmits information regarding the location of features on objects to the intraparietal sulcus and frontal eye fields. Shape processing occurs mainly in the intraparietal sulcus and lateral occipital complex, while orientation processing is distributed across primary somatosensory cortex, the parietal operculum, the anterior intraparietal sulcus, and a parieto-occipital region. For each of these properties, the respective areas outside primary somatosensory cortex also process corresponding visual information and are thus multisensory. Consistent with the distributed neural processing of haptic object properties, tactile spatial acuity depends on interaction between bottom-up tactile inputs and top-down attentional signals in a distributed neural network. Future work should clarify the roles of the various brain regions and how they interact at the network level.

scholarly journals Diversity of neurovascular coupling dynamics along vascular arbors in layer II/III somatosensory cortex

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Ravi L. Rungta ◽  
Marc Zuend ◽  
Ali-Kemal Aydin ◽  
Éric Martineau ◽  
Davide Boido ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Somatosensory Cortex ◽  
Cerebral Blood Volume ◽  
Transfer Functions ◽  
Neurovascular Coupling ◽  
Sensory Stimulation ◽  
Brain Regions ◽  
Blood Velocity ◽  
Functional Brain Imaging ◽  
Vascular Events

AbstractThe spatial-temporal sequence of cerebral blood flow (CBF), cerebral blood volume (CBV) and blood velocity changes triggered by neuronal activation is critical for understanding functional brain imaging. This sequence follows a stereotypic pattern of changes across different zones of the vasculature in the olfactory bulb, the first relay of olfaction. However, in the cerebral cortex, where most human brain mapping studies are performed, the timing of activity evoked vascular events remains controversial. Here we utilized a single whisker stimulation model to map out functional hyperemia along vascular arbours from layer II/III to the surface of primary somatosensory cortex, in anesthetized and awake Thy1-GCaMP6 mice. We demonstrate that sensory stimulation triggers an increase in blood velocity within the mid-capillary bed and a dilation of upstream large capillaries, and the penetrating and pial arterioles. We report that under physiological stimulation, response onset times are highly variable across compartments of different vascular arbours. Furthermore, generating transfer functions (TFs) between neuronal Ca2+ and vascular dynamics across different brain states demonstrates that anesthesia decelerates neurovascular coupling (NVC). This spatial-temporal pattern of vascular events demonstrates functional diversity not only between different brain regions but also at the level of different vascular arbours within supragranular layers of the cerebral cortex.

Reproducibility of human brain activity evoked by esophageal stimulation using functional magnetic resonance imaging

2007 ◽  
Vol 293 (1) ◽  
pp. G188-G197 ◽  
Author(s):  
Steven J. Coen ◽  
Lloyd J. Gregory ◽  
Lidia Yágüez ◽  
Edson Amaro ◽  
Mick Brammer ◽  
...  
Keyword(s):  
Brain Imaging ◽  
Anterior Cingulate Cortex ◽  
Somatosensory Cortex ◽  
Functional Mri ◽  
Brain Activity ◽  
Brain Regions ◽  
Anterior Cingulate ◽  
Primary Somatosensory Cortex ◽  
Imaging Studies ◽  
Painful Stimulation

Functional MRI is a popular tool for investigating central processing of visceral pain in healthy and clinical populations. Despite this, the reproducibility of the neural correlates of visceral sensation by use of functional MRI remains unclear. The aim of the present study was to address this issue. Seven healthy right-handed volunteers participated in the study. Blood oxygen level-dependent contrast images were acquired at 1.5 T while subjects received nonpainful and painful phasic balloon distensions (“on-off” block design, 10 stimuli per “on” period, 0.3 Hz) to the distal esophagus. This procedure was repeated on two further occasions to investigate reproducibility. Painful stimulation resulted in highly reproducible activation over three scanning sessions in the anterior insula, primary somatosensory cortex, and anterior cingulate cortex. A significant decrease in strength of activation occurred from session 1 to session 3 in the anterior cingulate cortex, primary somatosensory cortex, and supplementary motor cortex, which may be explained by an analogous decrease in pain ratings. Nonpainful stimulation activated similar brain regions to painful stimulation, but with greater variability in signal strength and regions of activation between scans. Painful stimulation of the esophagus produces robust activation in many brain regions. A decrease in subjective perception of pain and brain activity from the first to the final scan suggests that serial brain imaging studies may be affected by habituation. These findings indicate that for brain imaging studies that require serial scanning, development of experimental paradigms that control for the effect of habituation is necessary.

Representation of Shapes, Edges, and Surfaces Across Multiple Cues in the Human Visual Cortex

2008 ◽  
Vol 99 (3) ◽  
pp. 1380-1393 ◽  
Author(s):  
Joakim Vinberg ◽  
Kalanit Grill-Spector
Keyword(s):  
Visual Information ◽  
Random Motion ◽  
Intraparietal Sulcus ◽  
Shape Information ◽  
Global Shape ◽  
Lateral Occipital Complex ◽  
Multiple Cues ◽  
Visual Areas ◽  
Shape Selective ◽  
Cortical Regions

The lateral occipital complex (LOC) responds preferentially to objects compared with random stimuli or textures independent of the visual cue. However, it is unknown whether the LOC (or other cortical regions) are involved in the processing of edges or global surfaces without shape information. Here, we examined processing of 1) global shape, 2) disconnected edges without a global shape, and 3) global surfaces without edges versus random stimuli across motion and stereo cues. The LOC responded more strongly to global shapes than to edges, surfaces, or random stimuli, for both motion and stereo cues. However, its responses to local edges or global surfaces were not different from random stimuli. This suggests that the LOC processes shapes, not edges or surfaces. LOC also responded more strongly to objects than to holes with the same shape, suggesting sensitivity to border ownership. V7 responded more strongly to edges than to surfaces or random stimuli for both motion and stereo cues, whereas V3a and V4 preferred motion edges. Finally, a region in the caudal intraparietal sulcus (cIPS) responded more strongly to both stereo versus motion and to stereo surfaces versus random stereo (but not to motion surfaces vs. random motion). Thus we found evidence for cue-specific responses to surfaces in the cIPS, both cue-specific and cue-independent responses to edges in intermediate visual areas, and shape-selective responses across multiple cues in the LOC. Overall, these data suggest that integration of visual information across multiple cues is mainly achieved at the level of shape and underscore LOC's role in shape computations.

A TMS Investigation on the Role of Lateral Occipital Complex and Caudal Intraparietal Sulcus in the Perception of Object Form and Orientation

2017 ◽  
Vol 29 (5) ◽  
pp. 881-895 ◽  
Author(s):  
Philippe A. Chouinard ◽  
Deiter K. Meena ◽  
Robert L. Whitwell ◽  
Matthew D. Hilchey ◽  
Melvyn A. Goodale
Keyword(s):  
Critical Role ◽  
Brain Regions ◽  
Orientation Discrimination ◽  
Experimental Session ◽  
Intraparietal Sulcus ◽  
Lateral Occipital Complex ◽  
Match To Sample ◽  
Form Processing ◽  
Object Form ◽  
Object Features

We used TMS to assess the causal roles of the lateral occipital (LO) and caudal intraparietal sulcus (cIPS) areas in the perceptual discrimination of object features. All participants underwent fMRI to localize these areas using a protocol in which they passively viewed images of objects that varied in both form and orientation. fMRI identified six significant brain regions: LO, cIPS, and the fusiform gyrus, bilaterally. In a separate experimental session, we applied TMS to LO or cIPS while the same participants performed match-to-sample form or orientation discrimination tasks. Compared with sham stimulation, TMS to either the left or right LO increased RTs for form but not orientation discrimination, supporting a critical role for LO in form processing for perception- and judgment-based tasks. In contrast, we did not observe any effects when we applied TMS to cIPS. Thus, despite the clear functional evidence of engagement for both LO and cIPS during the passive viewing of objects in the fMRI experiment, the TMS experiment revealed that cIPS is not critical for making perceptual judgments about their form or orientation.

scholarly journals Responses of neurons in the primary somatosensory cortex to itch- and pain-producing stimuli in rats

2020 ◽  
Vol 123 (5) ◽  
pp. 1944-1954 ◽  
Author(s):  
Sergey G. Khasabov ◽  
Hai Truong ◽  
Victoria M. Rogness ◽  
Kevin D. Alloway ◽  
Donald A. Simone ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Somatosensory Cortex ◽  
Cortical Neurons ◽  
Small Area ◽  
Single Unit ◽  
Electrophysiological Study ◽  
Primary Somatosensory Cortex ◽  
Itch Sensation ◽  
The Face ◽  
Stimulation Of

Processing of information related to itch sensation at the level of cerebral cortex is not well understood. In this first single-unit electrophysiological study of pruriceptive cortical neurons, we show that neurons responsive to noxious and pruritic stimulation of the cheek of the face are concentrated in a small area of the dysgranular cortex, indicating that these neurons encode information related to itch and pain.

Neural Correlates of State- and Strength-based Perception

2014 ◽  
Vol 26 (4) ◽  
pp. 792-809 ◽  
Author(s):  
Mariam Aly ◽  
Charan Ranganath ◽  
Andrew P. Yonelinas
Keyword(s):  
Visual Information ◽  
Posterior Parietal Cortex ◽  
Empirical Work ◽  
Brain Regions ◽  
Posterior Cingulate Cortex ◽  
Lateral Occipital Complex ◽  
Information State ◽  
State Strength ◽  
Strength Based ◽  
Posterior Parietal

Perceptual judgments can be based on two kinds of information: state-based perception of specific, detailed visual information, or strength-based perception of global or relational information. State-based perception is discrete in the sense that it either occurs or fails, whereas strength-based perception is continuously graded from weak to strong. The functional characteristics of these types of perception have been examined in some detail, but whether state- and strength-based perception are supported by different brain regions has been largely unexplored. A consideration of empirical work and recent theoretical proposals suggests that parietal and occipito-temporal regions may be differentially associated with state- and strength-based signals, respectively. We tested this parietal/occipito-temporal state/strength hypothesis using fMRI and a visual perception task that allows separation of state- and strength-based perception. Participants made same/different judgments on pairs of faces and scenes using a 6-point confidence scale where “6” responses indicated a state of perceiving specific details that had changed, and “1” to “5” responses indicated judgments based on varying strength of relational match/mismatch. Regions in the lateral and medial posterior parietal cortex (supramarginal gyrus, posterior cingulate cortex, and precuneus) were sensitive to state-based perception and were not modulated by varying levels of strength-based perception. In contrast, bilateral fusiform gyrus activation was increased for strength-based “different” responses compared with misses and did not show state-based effects. Finally, the lateral occipital complex showed increased activation for state-based responses and additionally showed graded activation across levels of strength-based perception. These results offer support for a state/strength distinction between parietal and temporal regions, with the lateral occipital complex at the intersection of state- and strength-based processing.

Unconscious Touch Perception After Disruption of the Primary Somatosensory Cortex

2021 ◽  
pp. 095679762097055
Author(s):  
Tony Ro ◽  
Lua Koenig
Keyword(s):  
Somatosensory Cortex ◽  
Visual Information ◽  
Control Site ◽  
Primary Somatosensory Cortex ◽  
Tactile Information ◽  
Touch Perception ◽  
Contralateral Hand ◽  
Sensory Cortices ◽  
Transient Loss ◽  
The Brain

Brain damage or disruption to the primary visual cortex sometimes produces blindsight, a striking condition in which patients lose the ability to consciously detect visual information yet retain the ability to discriminate some attributes without awareness. Although there have been few demonstrations of somatosensory equivalents of blindsight, the lesions that produce “numbsense,” in which patients can make accurate guesses about tactile information without awareness, have been rare and localized to different regions of the brain. Despite transient loss of tactile awareness in the contralateral hand after transcranial magnetic stimulation (TMS) of the primary somatosensory cortex but not TMS of a control site, 12 participants (six female) reliably performed at above-chance levels on a localization task. These results demonstrating TMS-induced numbsense implicate a parallel somatosensory pathway that processes the location of touch in the absence of awareness and highlight the importance of primary sensory cortices for conscious perception.

Structural changes in the cerebral cortex upon modification of the periphery: barrels in somatosensory cortex

1977 ◽  
Vol 278 (961) ◽  
pp. 373-376 ◽  
Keyword(s):  
Cerebral Cortex ◽  
Somatosensory Cortex ◽  
Structural Changes ◽  
Morphological Data ◽  
Primary Somatosensory Cortex ◽  
Physiological Data ◽  
Mystacial Vibrissae ◽  
Number Combination

In the primary somatosensory cortex of the mouse there are approximately 35 cytoarchitectonic units, named ‘barrels’ (Woolsey & Van der Loos 1970), per hemisphere. There are also about 150 similar, but smaller, barrels. Each of the 35 large barrels is held to be the cortical endstation of the projections from one of the similar number of mystacial vibrissae on the animal’s contralateral muzzle. These barrels are arranged in a pattern that is topologically equivalent to the pattern of the whiskers. There are five rows of whiskers and of barrels, named A, B, C, D and E, and four whiskers and barrels that straddle the ends of the rows named α, β, γ and δ. Morphological data obtained from mice (Woolsey & Van der Loos 1970; Van der Loos & Woolsey 1973) together with physiological data obtained from the rat (Welker 1971) contributed to the recognition of the relation between whiskerpad and barrelfield. A whisker and its corresponding barrel bear the same letter-number combination rather as on a chessboard. (For a review, see Van der Loos (1976 b ).)In what follows, analyses referred to are on mice, unless otherwise stated.

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