Jun Tanji
Department of Physiology, Tohoku University
School of Medicine, Sendai, Japan
The performance of motor selection is based
on a variety of information given by sensory,
motivational, or internalized signals. I
intend to show how the information from different
sources is processed in different areas in
the cerebral cortex of subhuman primates
to select forthcoming action. First, I will
deal with the processing of visual signals
in the dorsal premotor cortex for motor selection.
Before initiating actions, we need to specify
both the motor target and the body part(s)
to use. Our new study suggests that the dorsal
premotor cortex is the site where the two
sets of information (extrapersonal and intrapersonal)
are integrated while planning an action.
Second, I will present evidence that neurons
in the rostral cingulate cortex play a crucial
role in selecting different movements based
on the judgement of reward. Finally, I will
introduce a novel aspect of information processing
in the superior parietal cortex (area 5).
We found that cellular activity in the superior
parietal lobule reflected the number of self-movement
executions, when the number of executions
was the sole source of information for the
selection of action.
References:
1. Shima K, Tanji J.
Role for cingulate motor area cells in voluntary
movement selection based on reward. Science.
282:1335-8, 1998.
2. Hoshi, E. and Tanji, J.
Integration of target and body-part information
in the premotor cortex when planning aciton.
Nature 408: 2000.