Varying target prevalence reveals two dissociable decision criteria in visual search.

ABSTRACT: Target prevalence powerfully influences visual search behavior. In most visual search experiments, targets appear on at least 50% of trials [1-3]. However, when targets are rare (as in medical or airport screening), observers shift response criteria, leading to elevated miss error rates [4, 5]. Observers also speed target-absent responses and may make more motor errors [6]. This could be a speed/accuracy tradeoff with fast, frequent absent responses producing more miss errors. Disproving this hypothesis, our experiment one shows that very high target prevalence (98%) shifts response criteria in the opposite direction, leading to elevated false alarms in a simulated baggage search. However, the very frequent target-present responses are not speeded. Rather, rare target-absent responses are

SUBMITTER: Wolfe JM 

PROVIDER: S-EPMC2818748 | biostudies-literature | 2010 Jan

REPOSITORIES: biostudies-literature