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Amelia Hunt, Patrick Cavanagh; Clocking saccadic remapping. Journal of Vision 2008;8(6):818. doi: 10.1167/8.6.818.
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When the eyes move, some cells in visual areas (FEF and LIP, among others) begin firing in anticipation of visual stimuli that will fall in their receptive fields once the saccade has landed (e.g., Duhamel, Colby, & Goldberg, 1992). This anticipatory firing can begin up to 50ms before the eyes begin to move. One consequence of this “remapping” may be (as Deubel & Schneider, 1996, have reported) that subjects think they are looking at the target location before their eyes actually arrive there. To investigate the timing of this shift in the apparent direction of gaze, we presented a ticking clock in the periphery as the saccade target. As soon as they heard a beep, subjects shifted fixation to the clock and reported the time on the clock when their eyes arrived. The reported time was earlier than the actual time on the clock by an average of 39ms (±21.8 ms). In a control condition, the clock moved to fixation (mimicking the retinal motion of the saccade without the eye movement). In this case, the reported time was later than the actual time on the clock by 27ms (±13.2 ms). Finally, when the clock's timing hand was not shown until the clock arrived at fixation, there was no longer a difference between saccade and control conditions. We conclude that there is a systematic anticipation of perceived direction of gaze that is consistent with the timing of saccadic remapping in visual cortices.
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