J. Klopp et al., Timing and localization of movement-related spectral changes in the human peri-Rolandic cortex: Intracranial recordings, NEUROIMAGE, 14(2), 2001, pp. 391-405
Event-related spectral power (ERSP) was measured from intracranial EEG and
used to characterize the time-course and localization of the Rolandic mu rh
ythms in 12 patients during the delayed recognition of words or faces (DR)
and the discrimination of simple lateralized visual targets (LVD). On each
trial, the subject decided whether to make manual response (Go) or not (NoG
o). ERSP increased on both Go and NoGo trials in peri-Rolandic regions of a
ll subjects with a peak latency of similar to 330-ms poststimulus and durat
ion of 260 ms during the DR task. The peak of this ERSP increase preceded m
ovement by similar to 300 ms. All subjects produced a subsequent movement s
pecific ERSP decrease of peri-Rolandic mu rhythms (starting similar to 90 m
s before the average reaction time) with an peak latency of similar to 800
ms and duration of similar to 520 ms. The LVD task produced bilateral movem
ent-selective readiness potentials and reproduced the movement-specific lat
e ERSP decreases seen in the DR task (strongest from 7-24 Hz). Furthermore,
the LVD task demonstrated that the late movement-related ERSP decrease is
larger for the contralateral hand. However, the LVD task did not consistent
ly reproduce the early ERSP increase seen in the DR task. Movement-related
ERSP decreases were widespread, occurring in pre- and post-Rolandic as well
as primary-motor, supplemental motor, and cingulate cortical regions. Othe
r cortical areas including frontal, temporal, and occipital regions did not
show movement-related ERSP changes. Peri-Rolandic ERSP decreases in mu rhy
thms correlate with the generation of a motor command. The early increases
in mu. may reflect a transient state of motor inhibition just prior to moto
r execution. (C) 2001 Academic Press.