The relationship between spatial attention and saccades in the frontoparietal network of the monkey.

Spatial attention bears a remarkable resemblance to saccadic eye movements from both a behavioural and a neurophysiological point of view. In this review, we examine the contributions of two cortical areas, namely the lateral intraparietal area (LIP) and frontal eye field (FEF), to saccades and attention and discuss the possible interactions between these two areas. Based on the results of electrophysiological studies and on inactivation studies performed in the macaque monkey, we propose that LIP is mainly involved in salience representation and an attentional selection mechanism that underlies saccade guidance, at least when two objects or locations are in competition in the visual environment. In contrast, we suggest that FEF is involved in coding and triggering saccadic eye movements, as well as in coding the location of attention or the attentional shifts. However, these two functions subserved by the FEF are dissociable at a neuronal level. Saccade planning and attentional selection are intimately coupled from a behavioural point of view but correspond to distinct functional operations.