Abstract
We examined the allocation of attention in a two-step-saccade task, probing several locations in space at different times following the onset of the central cue indicating the locations of the two targets. We found the expected advantage in detection performance at both the first and second saccade target locations increasing from around 150 msec before the first saccade, with a slight delay for the appearance of the advantage at the second saccade target. More interestingly, we also found an advantage at the remapped locations for the second target (and of the first as evaluated in a separate experiment), emerging just 75 msec before the saccade. These locations correspond to the positions the two saccade targets will have on the retina following the saccade but, prior to the saccade when these benefits are seen, they do not correspond to the saccade target locations in either retinotopic or spatiotopic coordinates. These results suggest that location pointers to saccade targets are updated by a predictive remapping process working in a retinotopic frame of reference, allowing attention to be allocated to the upcoming target location in advance of the saccade landing, lending behavioral support to the now classic physiological finding that many cells in retinotopically organized brain areas pre-activate in anticipation of stimuli that will be landing in their receptive fields.
This research was supported by a Chaire d'Excellence grant to Patrick Cavanagh.