Oxyopia Abstract

November 6, 2009
489 Minor Hall

Preeti Verghese, PhD
Scientist, Visual Psychophysics Laboratory, Smith-Kettlewell Eye Research Institute
Host: Michael Silver

Title

Active search for multiple targets under time pressure: where to look next?

Abstract

In daily life, we generally explore our surroundings visually before we plan action. What locations should the observer fixate first, particularly if multiple targets need to be detected within a limited time? We propose a principled approach to predicting the optimum strategy — a Bayesian framework that maximizes the information gained on each fixation. For multiple-target detection under brief presentations, the model predicts that the maximum information is gained when saccades are made to the most uncertain locations. These are locations that appear equally likely to be target or noise locations. The optimal strategy for finding multiple targets differs from that for a single-target search task, where efficient search is accomplished by moving the eyes to locations with the highest likelihood of signal. I will present eye movement data from the multiple-target search task and compare these to the predictions of a model that maximizes the information gained.

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