Role of the lateral intraparietal area in modulation of the strength of sensory-motor transmission for visually guided movements.

The lateral intraparietal area (LIP) has been implicated as a salience map for control of saccadic eye movements and visual attention. Here, we report evidence to link the encoding of saccades and saliency in LIP to modulation of several other sensory-motor behaviors in monkeys. In many LIP neurons, there was a significant trial-by-trial correlation between the firing rate just before a saccade and the postsaccadic or presaccadic pursuit eye velocity. Some neurons also showed trail-by-trial correlations of the firing rate of LIP neurons with the speed of "glissades" that occur at the end of saccades to stationary targets. LIP-pursuit correlations were spatially specific and were strong only when the target appeared in the receptive/movement field of the neuron under study. We suggest that LIP is a component of a salience representation that modulates the strength of visual-motor transmission for pursuit, and that may play a similar role for many movements, beyond its traditional roles in guiding saccadic eye movements and localizing attention.