Schematic threatening, friendly, and neutral faces were used to test the hypothesis that humans preferentially orient their attention toward threat. Using a visual search paradigm, participants searched for discrepant faces in matrices of otherwise identical faces. Across 5 experiments, results consistently showed faster and more accurate detection of threatening than friendly targets. The threat advantage was obvious regardless of whether the conditions favored parallel or serial search (i.e., involved neutral or emotional distractors), and it was valid for inverted faces. Threatening angry faces were more quickly and accurately detected than were other negative faces (sad or "scheming"), which suggests that the threat advantage can be attributed to threat rather than to the negative valence or the uniqueness of the target display.

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. Fear-relevant 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.

The temporal course of startle reflex modulation and autonomic response patterns to fear‐relevant and fear‐irrelevant pictures in subjects with high and low levels of animal fear was investigated. Thirty‐eight high‐fear and 48 low‐fear volunteers viewed photos of snakes and spiders and pictures of neutral and pleasant content. The slides were presented for 6 s or for only 150 ms, depending on the group. Acoustic startle probes were presented at five different times after slide onset. Relative potentiation of the startle responses started 300 ms after onset of snake/spider pictures in fearful subjects. This fear‐potentiated startle effect was maintained for the later probe times and was identical in the 150‐ms condition. Fear‐relevant pictures also prompted a sympathetically dominated autonomic response profile in fearful persons. These data support the idea that fear can be activated very rapidly, requiring only minimal stimulus input.

This study examined automatic elicitation of conditioned skin conductance responses (SCRs), when a backward masking procedure prevented the subject's conscious awareness of the conditioned stimuli (CSs). The CSs were pictures of emotional facial expressions. A differential conditioning procedure was used. One facial expression (e.g. an angry face) was aversively conditioned by a shock unconditioned stimulus, whereas another facial expression (e.g. a happy face) was never presented with the shock. After conditioning, the CSs were presented backwardly masked by a neutral face. This procedure prevented conscious perception of the CS. Nevertheless, reliable differential SCRs were obtained when the CS had been an angry face. This effect, however, was dependent on the subject's direction of attention. When attention was focused on the mask, no differential responding was observed. Thus it was concluded that, when fear-relevant stimuli (angry faces) served as the CS, elicitation of SCRs was automatic in the sense that it was possible even when the subjects were not aware of the stimuli presented. However, it was only partially automatic because the effect was modified by attention.