Shortening of the cortical silent period following transcranial magnetic brain stimulation during an experimental paradigm for generating contingent negative variation (CNV).
OBJECTIVE
We investigated changes in the cortical silent period (CSP) following transcranial magnetic cortical stimulation (TCMS) during a standard paradigm which was designed to evoke contingent negative variation (CNV) in ten normal subjects.


METHODS
We recorded the motor evoked potentials (MEP) and CSP during the inter-stimulus interval (ISI) of a CNV paradigm in ten normal subjects. The CNV paradigm consisted of a visual warning stimulus (S1) followed by a visual response stimulus (S2). The CSP following TCMS on the hand motor area was recorded from mildly contracted first dorsal interosseous muscles.


RESULTS
The CSP was significantly shortened during the ISI (P < 0.01, t test) with a highly significant correlation with the TCMS timing during the ISI (P < 0.02, Spearman's correlation coefficient), while the MEP amplitude and latency were unchanged.


CONCLUSIONS
The results suggested that shortening of the CSP was associated with neural processes related to preparation for voluntary movement during the paradigm.
Hoshiyama
M
M
Department of Integrative Physiology, National Institute for Physiological Sciences, Myodaiji, Okazaki, Japan. hosiyama@nips.ac.jp
Kakigi
R
R
D000328:Adult; D001921:Brain / Q000502:physiology*; D003265:Contingent Negative Variation / Q000502:physiology*; D004569:Electroencephalography; D004576:Electromyography; D005260:Female; D006801:Humans; D008280:Magnetics; D008297:Male; D009132:Muscles / Q000502:physiology; D013997:Time Factors