As snakes were probably the first predators of mammals, they may have been important agents of evolutionary changes in the primate visual system allowing fast visual detection of fearful stimuli (Isbell, 2006). Many EEG studies have established larger early posterior negativity (EPN) in response to snake stimuli when compared to other animal stimuli (e.g., Van Strien et al., 2014). The EPN is an eventrelated potential that reflects early selective visual processing of emotionally significant information. A recent study (Van Strien & Isbell, 2017) has emphasized the importance of the typical scales and scale patterns of the snake skin for the enhanced EPN in response to snake pictures. In the present research, we examined whether the EPN snake effect still exists when these scales are made less visible by blurring snake pictures, that is, we examined the influence of spatial frequency on the EPN snake effect.
Psychophysiology: an international journal
Department of Psychology, Education, and Child Studies

van Strien, J., & Beligiannis, N. (2017). High spatial frequencies drive the early posterior negativity in response to snake pictures. Psychophysiology: an international journal, 54. Retrieved from