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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2006-2-21
pubmed:abstractText
Many previous papers have reported the modulation of somatosensory evoked potentials (SEPs) during voluntary movement, but the locus and mechanism underlying the movement-induced centrifugal modulation of the SEPs elicited by a task-relevant somatosensory stimulus still remain unclear. We investigated the centrifugal modulation of the SEPs elicited by a task-relevant somatosensory stimulus which triggers a voluntary movement in a forewarned reaction time task. A pair of warning (S1: auditory) and imperative stimuli (S2: somatosensory) was presented with a 1 s interstimulus interval. Subjects were instructed to respond by moving the hand ipsilateral or contralateral to the somatosensory stimulation which elicits the SEPs. In four experiments, the locus and selectivity of the SEPs' modulation, the contribution of cutaneous afferents and the effect of contraction magnitude were examined, respectively. A control condition where subjects had no task to perform was compared to several task conditions. The amplitude of the frontal N30, parietal P30, and central P25 was decreased and that of the long latency P80 and N140 was increased when the somatosensory stimuli triggered a voluntary movement of the stimulated finger compared to the control condition. The N60 decreased with the movement of any finger. These results were considered to be caused by the centrifugal influence of neuronal activity which occurs before a somatosensory imperative stimulus. The present findings did not support the hypothesis that the inhibition of afferent inputs by descending motor commands can occur at subcortical levels. A higher contraction magnitude produced a further attenuation of the amplitude of the frontal N30, while it decreased the enhancement of the P80. Moreover, the modulation of neuronal responses seems to result mainly from the modulation of cutaneous afferents, especially from the moved body parts. In conclusion, the short- and long-latency somatosensory neuronal activities evoked by task-relevant ascending afferents from the moved body parts are regulated differently by motor-related neuronal activities before those afferent inputs. The latter activities may be associated with sensory gain regulation related to directing attention to body parts involved in the action.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0014-4819
pubmed:author
pubmed:issnType
Print
pubmed:volume
169
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
289-301
pubmed:dateRevised
2009-11-11
pubmed:meshHeading
pubmed-meshheading:16307265-Acoustic Stimulation, pubmed-meshheading:16307265-Adult, pubmed-meshheading:16307265-Afferent Pathways, pubmed-meshheading:16307265-Analysis of Variance, pubmed-meshheading:16307265-Attention, pubmed-meshheading:16307265-Electric Stimulation, pubmed-meshheading:16307265-Electroencephalography, pubmed-meshheading:16307265-Electromyography, pubmed-meshheading:16307265-Evoked Potentials, Somatosensory, pubmed-meshheading:16307265-Female, pubmed-meshheading:16307265-Fingers, pubmed-meshheading:16307265-Functional Laterality, pubmed-meshheading:16307265-Humans, pubmed-meshheading:16307265-Male, pubmed-meshheading:16307265-Median Nerve, pubmed-meshheading:16307265-Movement, pubmed-meshheading:16307265-Muscle Contraction, pubmed-meshheading:16307265-Psychomotor Performance, pubmed-meshheading:16307265-Somatosensory Cortex
pubmed:year
2006
pubmed:articleTitle
Centrifugal regulation of task-relevant somatosensory signals to trigger a voluntary movement.
pubmed:affiliation
Department of Integrative Physiology, National Institute for Physiological Sciences, Myodaiji, Okazaki, 444-8585, Japan. nikita@nips.ac.jp
pubmed:publicationType
Journal Article