Preparedness for action: responding to the snake in the grass.

A visual search study by Ohman, Flykt, and Esteves (2001) found shorter reaction times to snake and spider targets than to flower and mushroom targets. The present study investigated whether preparation for action in response to potential threats could explain this difference. In this study 2 main changes were made to the paradigm. All possible combinations of target and distractors were used to disentangle the effects of targets and distractors, and the responses were withheld until after detection. The results suggest that the shorter reaction times to snakes and spiders than to flowers and mushrooms resulted from preparation for faster action in response to potential threats than to nonthreats.