LACK OF SELECTIVITY FOR SIMPLE SHAPES DEFINED BY MOTION AND LUMINANCEIN STPA OF THE BEHAVING MACAQUE

THE anterior superior temporal polysensory area (STPa) has been hypoth esized to be an integration site for signals coming from the dorsal an d ventral visual pathways. To determine whether neurons in STPa were s elective for simple two-dimensional geometrical shapes and whether thi s area might integrate different visual cues, cells were tested with m otion- and luminance-defined shapes. Many neurons were activated by th e shape stimuli under at least one condition; however, very few showed selectivity for a particular shape under either condition. Only one n euron responded selectively to shapes defined by both cues. Thus selec tivity for simple shapes is not a prevalent property of STPa neurons a nd the integration of luminance and motion signals does not appear to occur at the single neuron level in STPa. (C) 1998 Rapid Science Ltd.