Invisible images of snakes and spiders capture visual attention

[摘要] There was evolutional pressure for primates including humans to be able to rapidly detect threatening visual cues such as snakes. Highly selective snake-sensitive neurons were discovered in the Pulvinar of monkeys that respond with very short latency to visual images of snakes (Van Le et al. 2013). Here, adopting a modified Posner attention cueing paradigm, we investigated whether images of snakes and spiders could influence observers' spatial attention even when these images were interocularly suppressed and rendered invisible. All 44 subjects also completed questionnaires assessing their snake and spider fear (SNAQ, SPQ; FSpQ, FSnQ)(Klorman et al. 1974, O'Donohue 1995). Results show that indeed invisible snake and spider images could attract spatial attention. For invisible snake images, briefer presentation (e.g., 100ms) was more effective in attracting attention, but the attentional effect disappeared when snake images lasted for 500ms, while attentional effect remained for spider images shown for 500ms. Somewhat surprisingly, when visible, neither the spider nor the snake images showed significant attention cueing effect. Individual observers' snake fear score (FSnQ) correlated with attentional effect only in a visible condition (r=0.3161, p=0.0366). These results suggest that unconscious and conscious processing of visual fearful information may have different mechanisms. Unconsciously, images of snakes and spiders capture observers' attention regardless of whether they expressed high or low trait fear of snakes and spiders.

[学科分类] 眼科学