Citation

Langeslag SJE, Van Strien JW. Brain Res. 2018; 1678: 297-303.

Affiliation

Department of Psychology, Education and Child Studies, Erasmus University Rotterdam, The Netherlands.

Copyright

(Copyright © 2018, International Brain Research Organization, Publisher Elsevier Publishing)

DOI

10.1016/j.brainres.2017.10.031

PMID

29102778

Abstract

Snakes and angry faces are common fear stimuli and both elicit an Early Posterior Negativity (EPN) in the event-related potential, which indicates that they capture early automatic visual attention. But because snakes have been a predatory threat for primates since long before communication through facial expressions evolved, we tested the hypothesis that the EPN for snakes would be more pronounced than the EPN for angry faces. We carefully controlled for differences between reptiles and faces by using lizards and neutral faces as control stimuli. Participants viewed a rapid serial visual presentation of snakes (i.e., threatening reptiles), lizards (i.e., non-threatening reptiles), angry faces (i.e., threatening humans), and neutral faces (i.e., non-threatening humans). EPNs for snakes (vs. lizards) and angry (vs. neutral) faces started to develop around 120 ms after stimulus onset. The EPN was of the same size for snakes and angry faces between 150-225 ms, but was larger for snakes than for angry faces between 225-300 ms, which suggests that snakes capture more extensive early automatic attention than angry faces. These findings correspond with the notion that the visual system is specifically tuned to detect snakes because of the prolonged pressure of snakes on primate evolution.

Copyright © 2017. Published by Elsevier B.V.

Language: en

Keywords

Anger; Early posterior negativity; Facial expressions; Snakes; Visual processing