title: Exogenous attention to fear: Differential behavioral and neural responses to snakes and spiders.
abstract: 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.
authors.affiliation: 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. Electronic address: sandra.soares@ua.pt.
authors.forename: Sandra C
authors.initials: SC
authors.lastname: Soares
authors.affiliation: Faculty of Psychology, Universidad Autónoma de Madrid, Spain.
authors.forename: Dominique
authors.initials: D
authors.lastname: Kessel
authors.affiliation: Faculty of Psychology, Universidad Autónoma de Madrid, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Hernández-Lorca
authors.affiliation: Faculty of Psychology, Universidad Autónoma de Madrid, Spain.
authors.forename: María J
authors.initials: MJ
authors.lastname: García-Rubio
authors.affiliation: Department of Psychology and Education, The University of Beira Interior, Portugal.
authors.forename: Paulo
authors.initials: P
authors.lastname: Rodrigues
authors.affiliation: William James Center for Research, ISPA-Instituto Universitário, Lisbon, Portugal; Institute of Health Sciences, Portuguese Catholic University, Portugal.
authors.forename: Nuno
authors.initials: N
authors.lastname: Gomes
authors.affiliation: Faculty of Psychology, Universidad Autónoma de Madrid, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Carretié
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000818:Animals; D001288:Attention / Q000502:physiology*; D001921:Brain / Q000502:physiology*; D004569:Electroencephalography; D005071:Evoked Potentials; D005239:Fear / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D011930:Reaction Time; D012815:Signal Processing, Computer-Assisted; D012911:Snakes; D013112:Spiders; D013997:Time Factors; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: ERPs; Evolution; Exogenous attention; Snakes; Spiders