MULTIPLE NON-PRIMARY MOTOR AREAS IN THE HUMAN CORTEX.
1Gereon R. Fink, 1Richard S.J. Frackowiak, 2Uwe Pietrzyk, 1,3Richard E.
Passingham.
1Wellcome Department of Cognitive Neurology, Institute of Neurology, London
WC1N 3BG, UK & MRC Clinical Sciences Centre, London W12 OHS, UK, 2Max-Planck
Institute for Neurological Research, 50931 Cologne, FRG, 3Department of
Experimental Psychology, University of Oxford, Oxford OX1 3UD, UK.
APStracts 4:0011N, 1997.
ABSTRACT
We measured the distribution of regional cerebral blood flow with positron
emission tomography while three subjects moved their hand, shoulder or leg.
The images were co- registered with each individual's anatomical magnetic
resonance scans. The data were analyzed for each individual to avoid
intersubject averaging and so to preserve individual gyral anatomy. Instead of
inspecting all pixels, we prospectively restricted the data analysis to
particular areas of interest. These were defined on basis of the anatomical
and physiological literature on nonhuman primates. By examining only a subset
of areas, we strengthened the power of the statistical analysis and thereby
increased the confidence in reporting single subject data. On the lateral
convexity motor related activity was found for all three subjects in the
primary motor cortex, lateral premotor cortex and an opercular area within the
premotor cortex. In addition there was activation of somatosensory cortex
(SI), the supplementary somatosensory area (SII) in the Sylvian fissure, and
parietal association areas (Brodmann areas 5 and 40). There was also
activation in the insula. We suggest that the activation in the dorsal
premotor cortex may correspond with PMd as described in the macaque brain. We
propose three hypotheses as to the probable location of PMv in the human
brain. On the medial surface motor related activity was found for all three
subjects in the leg areas of the primary motor cortex and somatosensory
cortex, and also activity for the hand, shoulder and leg in the supplementary
motor area (SMA) on the dorsal medial convexity, and in three areas in the
cingulate sulcus. We suggest that the three cingulate areas may correspond
with CMAr, CMAd and CMAv as identified in the macaque brain. Somatotopic
mapping was demonstrated in the primary motor and primary somatosensory
cortex. In all three subjects the arm region lay anterior to the leg region in
parietal area 5. Also in all three subjects the arm region lay anterior to the
leg region in the supplementary motor cortex.
Received 14 June 1996; accepted in final form 18 December 1996.
APS Manuscript Number J474-6.
Article publication pending J. Neurophysiol.
ISSN 1080-4757 Copyright 1997 The American Physiological Society.
Published in APStracts on 21 January 1997