Cognitive Neuroscience Colloquium: Where

Colloquium | January 30 | 3:30-5 p.m. | 5101 Tolman Hall

 Patrick Cavanagh, Department of Psychology, Glendon College and Department of Psychological and Brain Sciences, Dartmouth College

 Department of Psychology

How do we know where things are? Recent results indicate that an object’s visual location is constructed at a high level where, critically, an object’s motion is discounted to recover its current location, much like we discount the illumination when we perceive color. As a result we sometimes see a target far from its actual location. These predictions operate differently for eye movements, however, and stimuli that can be seen far from their actual location nevertheless drive saccades to their physical position with far less influence from the motion-induced position shift. This dissociation establishes two distinct representations of spatial coordinates, supported by imaging results, and we ask whether spatial attention directs resources to the perceived location of an attended target or to its physical location, where a saccade would land. Using illusory line motion as a probe for the location of attention, we find that attention is based in saccade not perceptual coordinates.