Panic search: fear produces efficient visual search for nonthreatening objects.

The ability to rapidly detect and respond to potentially threatening stimuli has survival value that has led researchers to posit that a threat detection system should have evolved within human cognitive architecture. LeDoux and his colleagues (Armony, Servan-Schreiber, Cohen, & LeDoux, 1997; LeDoux, 2000; Phelps & LeDoux, 2005) have proposed an early-warning system that is mediated by the amygdala. Under this view, the amygdala’s rapid, preattentive evaluation of the emotional relevance of a threatening stimulus produces a rapid shift of attention toward the threat. Behavioral studies demonstrating efficient visual search for threatening targets (Eastwood, Smilek, & Merikle, 2001; Öhman, Flykt, & Esteves, 2001) and the capture of attention by threatening stimuli (Koster, Crombez, Van Damme, Verschuere, & De Houwer, 2004; Smith, Most, Newsome, & Zald, 2006) support the claim that attention rapidly shifts toward threatening stimuli. Importantly, the effect of this mechanism is selective: It increases processing for only the threat-relevant object. Ideally, the detection of threat would also produce a more generalized increase in processing efficiency, thereby allowing one to rapidly identify objects that would be beneficial to fleeing or fighting the threat, objects that themselves may not be threatening. Very little research has investigated how threatening stimuli influence the processing of non-threat-relevant stimuli. Recently, Phelps, Ling, and Carrasco (2006) ran such a study and found that contrast sensitivity increased when a fearful face preceded a contrast-discrimination task. They concluded that ‘‘people actually see better in the presence of emotional stimuli’’ (p. 298). How increased visual processing of contrast would be advantageous in an emotional situation was not directly addressed by their study. Here we posit that increased low-level visual processing allows one to more rapidly find objects that may help one fight or flee from the threat. This extension predicts that threat-relevant stimuli should produce a generalized increase in the efficiency with which one can search the environment. To examine this issue, we had a spatially noninformative emotional face cue appear before each trial in a visual search task.