A V1 Model of Pop Out and Asymmetty in Visual Search

Unique features of targets enable them to pop out against the background, while targets defined by lacks of features or conjunctions of features are more difficult to spot. It is known that the ease of target detection can change when the roles of figure and ground are switched. The mechanisms underlying the ease of pop out and asymmetry in visual search have been elusive. This paper shows that a model of segmentation in VI based on intracortical interactions can explain many of the qualitative aspects of visual search. 1 Introduction Visual search is closely related to visual segmentation, and therefore can be used to diagnose the mechanisms of visual segmentation. For instance, a red dot can popout againsta background of green distractor dots instantaneously, suggesting that only pre-attentive mechanisms are necessary (Treisman et aI, 1990).