Abstract # 13343 Poster # 101:

Scheduled for Thursday, August 22, 2019 06:00 PM-08:00 PM: (Alumni Lounge) Poster Presentation


C. Jensen and N. G. Caine
California State University San Marcos, Department of Psychology, San Marcos, CA 92096, USA
     According to Snake Detection Theory (SDT) (Isbell, 2006), the primate subcortical visual pathway allows for rapid, unconscious detection of snakes prior to consciously mediated avoidance responses. Primates do detect snakes more quickly than other objects in laboratory visual search tasks, but SDT has not been adequately tested under natural conditions, particularly as it involves the unconscious component of snake detection. If SDT is correct, we should see physiological reactions to snake exposure even if the viewer is not aware of having seen the snake. We had human (Homo sapiens) participants watch videos of a virtual hike that followed a path along which a realistic model of a rattlesnake or one of two control items (a rabbit model or a bottle) had been placed. Galvanic skin response (GSR) was monitored while participants viewed the video. In support of SDT, GSRs of participants who did not report seeing the stimulus (N=8 of the 20 participants in the snake condition, N=11 of the 17 participants in the rabbit condition, N=11 of the 17 participants in the bottle condition) were significantly different across conditions (F (2,27)=7.4, p=0.003). Planned comparisons showed that the snake condition generated greater (p<.05) GSRs than both the rabbit and bottle conditions. Establishing an unconscious reaction to snakes under naturalistic conditions provides a critical test of SDT.