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dc.contributor.advisor Caine, Nancy en_US
dc.contributor.author Jensen, Cody
dc.date.accessioned 2019-12-03T23:56:32Z
dc.date.available 2019-12-03T23:56:32Z
dc.date.issued 2019-12-03
dc.date.submitted 2019-11-26
dc.identifier.uri http://hdl.handle.net/10211.3/214336
dc.description.abstract According to Isbell’s (2006) Snake Detection Theory, the need to rapidly detect and thus avoid snakes had a major impact on the evolution of the primate visual system. Snake Detection Theory rests on the assumption that there are both cortical (conscious) and subcortical (unconscious) brain structures and mechanisms that are responsible for rapid visual detection of and quick avoidance reactions to snakes. Evidence in support of Snake Detection Theory comes from a variety of studies that assess speed and accuracy of snake detection, evaluate neurophysiological responses to snakes, and measure arousal reactions in response to snakes compared to other stimuli. However, evidence for Snake Detection Theory primarily comes from visual search tasks and presentations of images on a computer screen. There are no studies that look for physiological evidence of pre-attentive awareness of a snake in a naturalistic context. If Snake Detection Theory applies to primates in natural conditions, we should see evidence of both preferential detection of snakes and evidence of physiological reactions to snakes (heart rate, HR, and galvanic skin response, GSR) even when there is not conscious awareness of the snake’s presence. Therefore, I proposed the following five hypotheses by having participants take a virtual hike in which a realistic model of a snake, rabbit, or bottle has been placed on the trail. I predicted that: 1) snakes would be reported as seen more often than rabbits or bottles; 2) among participants who reported seeing the stimulus, larger GSR responses would occur during stimulus exposure in the snake compared to the rabbit or bottle conditions; 3) among participants who did not report seeing the stimulus, larger GSR responses would occur during stimulus exposure in the snake compared to the rabbit or bottle conditions; 4) among participants who reported seeing the stimulus, greater decelerations over baseline heart rate would occur during stimulus exposure in the snake compared to the rabbit or bottle conditions; 5) among participants who did not report seeing the stimulus, greater decelerations over baseline heart rate would occur during stimulus exposure in the snake compared to the rabbit or bottle conditions. I also asked a research question about the relationship, if any, between self-reported snake fears and detection/reaction in the snake condition. I found that hypotheses 1- 4 were supported, and hypothesis 5 showed similar trends but failed to reach significance. There was no relationship between snake fears and detection or HR or GSR changes. The results of my study provide evidence in support of Snake Detection Theory by being the first to show that snakes are detected more often than controls, and elicit conscious and unconscious physiological responses, in a naturalistic context. en_US
dc.description.sponsorship Psychological Science en_US
dc.language.iso en_US en_US
dc.subject Snake Detection Theory en_US
dc.subject Visual Pathways en_US
dc.subject Conscious and Unconscious Responses en_US
dc.title Examining Snake Detection Theory: Conscious and Unconscious Responses to Snakes en_US
dc.genre Thesis en_US
dc.contributor.committeemember Berry, Daniel en_US
dc.contributor.committeemember Calvillo, Dustin en_US


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