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The more briefly one looks, the more effectively one `sees' : vision by V1| old_uid | 1244 |
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| title | The more briefly one looks, the more effectively one `sees' : vision by V1 |
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| start_date | 2006/05/17 |
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| schedule | 14h30 |
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| online | no |
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| location_info | Leolin price lecture theatre |
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| details | 2e intervention à 15h45 |
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| summary | I show that a visual search task can be better performed when one views the search array for a shorter time, and suggest an account of this phenomenon based on an analysis of V1's contribution to vision. The cost of a prolonged view comes from the interference of higher level object recognition on lower level image feature
processing. A similar effect underlies the trick for art novices of drawing a portrait upside down in order to reproduce lower level image features, such as contours, with less interference from higher level face cognition.
In our task, the search target has an uniquely oriented bar but is identical in shape to distractors. Lower level image feature processes enable the unique orientation to pop out, attracting gaze towards the target. Subsequently, higher level object processes, involving focused attention, recognize the target object in a viewpoint
invariant manner, confusing the target as being a distractor and interfering with the task. Lower and higher processes lead to their respective behavioural decisions manifested in eye movements and ultimate task performances.
I will show physiological and computational evidence implicating V1 mechanisms for the lower level feature pop out, and review data about higher object processes in higher brain areas. |
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| oncancel | Attention changement de lieu |
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| responsibles | Dayan |
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