Selective Visual Attention and Visual Search: Behavioral and Neural Mechanisms

Abstract

Publisher Summary Visual search is one task domain in which visual attention is studied extensively. Visual search studies are well-suited as a proxy for real world attentional requirements as features of the natural environment such as object clutter are captured while a controlled stimulus environment is maintained. In fact, visual search tasks are used to examine patterns of visual attention over the past several decades. A particularly prolific subset of these studies focuses on the conditions under which the reaction time (RT) and accuracy required to locate the target are affected by distractor set size. Cases in which time to detect a target is unaffected by increasing the number of distractors (e.g., 5 ms/distractor item) are labeled as ‘‘preattentive,’’ whereas cases in which detection time is significantly slowed by increasing numbers of distractors (e.g., 50 ms/item) are labeled ‘‘attentive.’’ These different search rates are also referred to as ‘‘parallel’’ vs. ‘‘serial,’’ ‘‘disjunctive’’ vs. ‘‘conjunctive,’’ or ‘‘simple’’ vs. ‘‘difficult’’ (although for the suggestion that the preattentive/attentive distinction is orthogonal to the parallel/serial dichotomy. the terms ‘‘preattentive’’ and ‘‘attentive’’ in relation to simple and difficult search have been a point of contentious debate. In sum, there is much work to be done to understand the behavioral and neural mechanisms that underlie visual search processes in particular, and visual attention as a whole. Convergence from multiple methodologies is particularly important as the data can force to modify existing concepts and seek new formulations for describing functional systems that give rise to human behavior.