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Brittany J. Dungan, Edward K. Vogel; An Attention-centered neural marker for shifts in eye position. Journal of Vision 2014;14(10):642. doi: https://doi.org/10.1167/14.10.642.
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Past research from our lab has investigated the potential role of visual working memory (VWM) in perceptual stability. We have previously shown that item representations remain in the initial contralateral, encoding hemisphere following a shift in gaze, with items also being represented in the ipsilateral hemisphere over time (Dungan & Vogel, VSS Poster 2012; 2013). Here we extended these findings by recording event related potentials (ERPs) while subjects performed a change detection task for laterally-presented colored squares. Subjects fixated a central cross at the beginning of each trial and were cued to attend to the left or right visual field before the presentation of a memory array. In Experiment 1, on half the trials subjects were cued to maintain central fixation throughout the trial, while on the other half of trials subjects were cued to shift their gaze to a lateral fixation cross presented 8.71 degrees to the left or right. In a blocked design, this eye movement either was over the attended items or away from them. Following the onset of the eye movement, we observed a large contralateral negativity when the eyes were moved over the attended items and a contralateral positivity when they moved away from them. Thus, the polarity of this activity is determined by the relative position of the attended items and was not determined by the absolute direction of the eye movement. In Experiment 2, we manipulated the distance between the central and lateral fixations crosses (7.94 vs. 12.18 deg) and found that the amplitude of the deflection was greater for larger shifts in eye position. Together these results reveal a neural marker of eye position shifts that charts the distance of the shift and is centered to the current focus of attention.
Meeting abstract presented at VSS 2014
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