scispace - formally typeset
Search or ask a question
Topic

Somatosensory system

About: Somatosensory system is a research topic. Over the lifetime, 6371 publications have been published within this topic receiving 316900 citations.


Papers
More filters
Journal ArticleDOI
TL;DR: It is argued that pain perception involves some of the representational properties of exteroceptive senses, such as vision and touch, and shown that the neural coding of noxious stimuli, and consequent experience of pain, are both strongly influenced when cognitive representations of the body are activated by viewing the body, as opposed to viewing another object.

173 citations

Journal ArticleDOI
TL;DR: The long-term changes described here may be involved in experimentally- and naturally-induced cortical reorganization in anesthetized cats.
Abstract: Averaged evoked potentials from primary somatosensory cortex (SEPs) were recorded before and after pairing the peripheral stimuli with electrical activation of the basal forebrain (BF) in anesthetized cats. Four pulses at 400 Hz were delivered to the BF 120 ms before each cutaneous stimulus and 10 to 660 such pairings were found to produce an enlargement of the SEP in 10 of 11 animals. The average increase in amplitude of the initial peak of the SEP was 69%. The SEP remained enhanced in five of six animals that were tested an hour or more after the pairing, and in one case the SEP was tested 4.5 h after pairing without diminution. The effective BF sites were located in the substantia innominata and at the rostral pole of the globus pallidus, regions known to contain many cholinergic cell bodies. Enhancement occurred consistently only if stimulation of the BF site elicited a positive wave in the cortex at a latency of 11 to 18 ms. Repeated BF stimulation without cutaneous input did not produce a change in subsequent SEPs. The long-term changes described here may be involved in experimentally- and naturally-induced cortical reorganization.

173 citations

Journal ArticleDOI
TL;DR: In this article, the authors used a simple electrical nerve stimulation technique together with fMRI to study pain process in the human cortex and found that stimuli that evoked non-painful tingling sensations activated the contralateral SI but not Cg.
Abstract: Functional MRI (fMRI) can detect changes from resting levels of blood flow and oxygenation during task performance (i.e. activation). We used a simple electrical nerve stimulation technique together with fMRI to study pain process in the human cortex. Images of the primary somatosensory (SI) and cingulate cortex (Cg) were obtained from subjects during stimulation at painful and non-painful intensities. Stimuli that evoked non-painful tingling sensations activated the contralateral SI but not Cg. Stimuli that evoked painful sensations activated both the contralateral SI and Cg. These data indicate that fMRI can detect pain-related changes in SI and Cg evoked by electrical stimulation of peripheral nerves. These findings add to the evidence for a role of SI and Cg in human pain processes and provide a simple method of stimulus delivery for its study.

173 citations

Journal ArticleDOI
TL;DR: Functional magnetic resonance imaging evidence is provided for the functional delineation of somatosensory representations in the human central sulcus region and strong evidence for the existence of a distinct representation within area 3a in humans is provided.
Abstract: The segregation of sensory information into distinct cortical areas is an important organizational feature of mammalian sensory systems. Here, we provide functional magnetic resonance imaging (fMRI...

173 citations

Journal ArticleDOI
TL;DR: It is suggested that mixed nerve stimulation activates areas 3a and 3b whereas cutaneous stimulation activates mainly area 3b at the human primary somatosensory cortex.
Abstract: Magnetic responses evoked by stimulation of the mixed median nerve at the wrist and its cutaneous branches on the glabrous skin of the index and middle fingers were studied. The first responses to mixed nerve stimulation peaked at 19-24 ms, and those to cutaneous nerve stimulation about 4 ms later. The responses, up to a latency of 150 ms, reversed in polarity between the upper and lower parts of the rolandic fissure. Equivalent dipoles for the mixed nerve stimulation were stronger and they lay statistically significantly deeper from the scalp than those activated by the cutaneous nerve stimulation. It is suggested that mixed nerve stimulation activates areas 3a and 3b whereas cutaneous stimulation activates mainly area 3b at the human primary somatosensory cortex. Statistical procedures were developed for comparison of different field patterns and for determining confidence limits of source model parameters. For these purposes the quality and quantity of the noise were studied. The error caused by inaccuracies in the positioning of the magnetometer was found to be minimal in comparison with the signal noise which was estimated from the standard deviation of the averaged response.

172 citations


Network Information
Related Topics (5)
Hippocampal formation
30.6K papers, 1.7M citations
91% related
Prefrontal cortex
24K papers, 1.9M citations
91% related
Hippocampus
34.9K papers, 1.9M citations
91% related
Synaptic plasticity
19.3K papers, 1.3M citations
89% related
Dopaminergic
29K papers, 1.4M citations
89% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20241
2023463
2022986
2021238
2020233
2019234