Soares Sandra C, Kessel Dominique, Hernández-Lorca María, García-Rubio María J, Rodrigues Paulo, Gomes Nuno, Carretié Luis
CINTESIS.UA, Department of Education and Psychology, University of Aveiro, Portugal; William James Center for Research, ISPA-Instituto Universitário, Lisbon, Portugal; Department of Clinical Neuroscience, Division for Psychology, Karolinska Institutet, Sweden.
Faculty of Psychology, Universidad Autónoma de Madrid, Spain.
Neuropsychologia. 2017 May;99:139-147. doi: 10.1016/j.neuropsychologia.2017.03.007. Epub 2017 Mar 6.
Research has consistently shown that threat stimuli automatically attract attention in order to activate the defensive response systems. Recent findings have provided evidence that snakes tuned the visual system of evolving primates for their astute detection, particularly under challenging perceptual conditions. The goal of the present study was to measure behavioral and electrophysiological indices of exogenous attention to snakes, compared with spiders - matched for rated fear levels but for which sources of natural selection are less well grounded, and to innocuous animals (birds), which were presented as distracters, while participants were engaged in a letter discrimination task. Duration of stimuli, consisting in a letter string and a concurrent distracter, was either presented for 180 or 360ms to explore if the stimulus duration was a modulating effect of snakes in capturing attention. Results showed a specific early (P1) exogenous attention-related brain potential with maximal amplitude to snakes in both durations, which was followed by an enhanced late attention-related potential (LPP) showing enhanced amplitudes to spiders, particularly under the longer exposure durations. These results suggest that exogenous attention to different classes of threat stimuli follows a gradual process, with the most evolutionary-driven stimulus, i.e., snakes, being more efficient at attracting early exogenous attention, thus more dependent on bottom-up processes.
研究一直表明，威胁刺激会自动吸引注意力，以激活防御反应系统。最近的研究结果提供了证据，表明蛇为了敏锐地被察觉，塑造了灵长类动物进化过程中的视觉系统，特别是在具有挑战性的感知条件下。本研究的目的是测量对外源性注意蛇的行为和电生理指标，并与蜘蛛（恐惧等级匹配，但自然选择的依据不太充分）以及作为干扰物呈现的无害动物（鸟类）进行比较，同时让参与者进行字母辨别任务。刺激物由一个字母串和一个同时出现的干扰物组成，呈现时间为180毫秒或360毫秒，以探究刺激持续时间是否是蛇在吸引注意力方面的调节效应。结果显示，在两个持续时间内，都存在一种特定的早期（P1）与外源性注意相关的脑电活动，对蛇的反应幅度最大，随后是一种增强的晚期注意相关电位（LPP），对蜘蛛的反应幅度增强，特别是在较长的暴露持续时间下。这些结果表明，对外源性注意不同类别的威胁刺激遵循一个渐进的过程，其中进化驱动最强的刺激物，即蛇，在吸引早期外源性注意方面更有效，因此更依赖自下而上的过程。
