COMBINATION OF HAND AND GAZE SIGNALS DURING REACHING - ACTIVITY IN PARIETAL AREA 7M OF THE MONKEY

The role of area 7m has been studied by recording the activity of sing le neurons of monkeys trained to fixate and reach toward peripheral ta rgets. The target was randomly selected from eight possible locations on a virtual circle, of radius 30 degrees visual angle from a central target. Three tasks were employed to dissociate hand- from eye-related contributions. In the first task, animals looked and reached to the p eripheral target. In a second task, the animal reached to the peripher al target while maintaining fixation on the central target. In tile th ird task, the monkey maintained fixation on peripheral targets that we re spatially coincident with those of the reaching tasks. The results show that cell activity in area 7m relates, for some cells to eye posi tion, for others to hand position and movement, and for the majority o f cells to a combination of visuomanual and oculomotor information. Th is area, therefore, seems to perform an early combination of informati on in the processing leading from target localization to movement gene ration.