ScienceDirect - Vision Research : Task constraints in visual working memory

ScienceDirect - Vision Research : Task constraints in visual working memory: "Task constraints in visual working memory
Mary M. Hayhoe*, , , David G. Bensinger* and Dana H. Ballard*

* Center for Visual Science, University of Rochester, Rochester, New York NY 14627, U.S.A.

Received 2 September 1996; accepted 21 March 1997. ; Available online 28 June 1999.

Abstract
This paper examines the nature of visual representations that direct ongoing performance in sensorimotor tasks. Performance of such natural tasks requires relating visual information from different gaze positions. To explore this we used the technique of making task relevant display changes during saccadic eye movements. Subjects copied a pattern of colored blocks on a computer monitor, using the mouse to drag the blocks across the screen. Eye position was monitored using a dual-purkinje eye tracker, and the color of blocks in the pattern was changed at different points in task performance. When the target of the saccade changed color during the saccade, the duration of fixations on the model pattern increased, depending on the point in the task that the change was made. Thus different fixations on the same visual stimulus served a different purpose. The results also indicated that the visual information that is retained across successive fixations depends on moment by moment task demands. This is consistent with previous suggestions that visual representations are limited and task dependent. Changes in blocks in addition to the saccade target led to greater increases in fixation duration."