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CMB Monday Seminar - Tom Campbell

Apr 12, 2010
from 04:00 PM to 05:30 PM

267 Cousteau Place, Large Conference Room

Vision has a memory: An objective ERP index of visual distraction by colour change


People prioritize the processing of sudden changes over ongoing mental activities, even when they have been instructed to ignore the feature of their environment that changes. That is, unexpected prominent changes cause distraction. The ability to process such a change requires a memory for the preceding perceptual features of that environment. Here we revealed a new component of the electrical potentials generated by the brain in response to a change of a highly salient visual property: color. This component, which we term the Change-Event-Related-Negativity (CERN), is generated posteriorly over the left hemisphere and elicited 120-160 ms after the onset of unexpected color change. The amplitude of CERN indexes visual distraction in response to such color change within a visual scene, when the task involves identifying a unique shape within that scene, whilst ignoring a unique color. The brain's memory for the color of the preceding visual scenes must persist from trial-to-trial for CERN to index distraction of performance by color-change upon this visual task. Therefore, in the case of the neural code for color, vision has a memory.

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