F. Lacquaniti, E. Guigon, L. Bianchi, S. Ferraina, R. Caminiti; Representing Spatial Information for Limb Movement: Role of Area 5 in the Monkey. Cereb Cortex 1995; 5 (5): 391-409. doi: 10.1093/cercor/5.5.391
How is spatial information for limb movement encoded in the brain? Computational and psychophysical studies suggest that beginning hand position, via-points, and target are specified relative to the body to afford a comparison between the sensory (e. g., kinesthetic) reaf-ferences and the commands that generate limb movement Here we propose that the superior parietal lobule (Brodmann area 5) might represent a substrata for a body-centered positional code. Monkeys made arm movements in different parts of 3D space in a reaction-time task. We found that the activity of area 5 neurons can be related to either the starting point or the final point or combinations of the two. Neural activity is monotonicalty tuned in a body-centered frame of reference, whose coordinates define the azimuth, elevation, and distance of the hand. Each spatial coordinate tends to be encoded in a different sub-population of neurons. This parcellation could be a neural correlate of the psychophysical observation that these spatial parameters are processed in parallel and largely independent of each other in man.