OCULOMOTOR ACTIVITY AND VISUAL-SPATIAL ATTENTION

Subjects made a horizontal or vertical saccade in response to a non-la teralized auditory stimulus. Simple manual reaction time (RT) for the detection of light targets at extrafoveal locations was modulated by t he intention to make the saccade insofar as RT to targets presented at the saccadic goal location or in the hemifield containing that locati on was faster than RT to targets presented at the opposite, mirror-sym metric location. This RT difference was maximal prior to the beginning of the saccade and vanished after saccade termination, indicating tha t the effect was caused by the neural activity leading to the saccade rather than to the eye movement or the eye position per se. The result s have implications for the understanding of the relations between vis ual spatial attention and oculomotor control, especially with regard t o inhibitory phenomena arising from the non-correspondence between the line of sight and the focus of attention.