Emotion drives attention: Detecting the snake in the grass.

Participants searched for discrepant fear-relevant pictures (snakes or spiders) in grid-pattern arrays of fear-irrelevant pictures belonging to the same category (flowers or mushrooms) and vice versa.Fearrelevant pictures were found more quickly than fear-irrelevant ones.Fear-relevant, but not fear-irrelevant, search was unaffected by the location of the target in the display and by the number of distractors, which suggests parallel search for fear-relevant targets and serial search for fear-irrelevant targets.Participants specifically fearful of snakes but not spiders (or vice versa) showed facilitated search for the feared objects but did not differ from controls in search for nonfeared fear-relevant or fear-irrelevant, targets.Thus, evolutionary relevant threatening stimuli were effective in capturing attention, and this effect was further facilitated if the stimulus was emotionally provocative.Mammals evolved in environments where resources and dangers were unpredictably distributed in space and time.The reproductive potential of individuals, therefore, was predicated on the ability to efficiently locate critically important events in the surroundings.Resources such as food and mating partners were the objects of active foraging, whereas dangers had to be reflexively detected to be adaptively avoided.Framed in this way, an important component of the adaptive problem concerns different varieties of selective attention.Following James (1890), researchers have commonly distinguished between active and passive attention.The former is conceptualized as goal-driven and voluntarily controlled in a top-down fashion, whereas the latter is stimulusdriven and governed by bottom-up perceptual processes.Thus, in foraging for food, mammals would rely on active, goal-driven processes, and in detecting threat, on passive, stimulus-driven attention.Indeed, James (1890, pp.416-417) included threatening events such as "wild animals," "metallic things," "blows," and "blood" among stimuli likely automatically and reflexively to capture attention.In agreement with this distinction, there are experimental data suggesting a contrast between voluntary, effortdemanding attentional processes with a slow time course, and quickly dissipating selective processes that are rapidly and automatically activated by peripheral stimulus events (e.