Pupillometry reveals the physiological underpinnings of the aversion to holes

• Type of Material: Article
• Authors: Vladislav Ayzenberg, Emory University; Meghan R. Hickey, Emory University; Stella Lourenco, Emory University
• Language: English
• Date: 2018
• Publisher: PeerJ
• Publication Version: Final Published Version
• Copyright Statement: ©2018 Ayzenberg et al.
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.7717/peerj.4185
• Title of Journal or Parent Work: PeerJ
• ISSN: 2167-8359
• Volume: 6
• Start Page: e4185
• End Page: e4185
• Grant/Funding Information: This work was partially supported by an National Institutes of Health (NIH) institutional training grant (T32 HD071845) and a Scholarly Inquiry and Research at Emory (SIRE) Fellowship awarded to MRH.
• Keywords: Fear; Psychophysiology; Vision; Trypophobia; Holes; Disgust; Pupillometry
• Research Categories: Psychology, Behavioral; Psychology, General

Abstract

An unusual, but common, aversion to images with clusters of holes is known as trypophobia. Recent research suggests that trypophobic reactions are caused by visual spectral properties also present in aversive images of evolutionary threatening animals (e.g., snakes and spiders). However, despite similar spectral properties, it remains unknown whether there is a shared emotional response to holes and threatening animals. Whereas snakes and spiders are known to elicit a fear reaction, associated with the sympathetic nervous system, anecdotal reports from self-described trypophobes suggest reactions more consistent with disgust, which is associated with activation of the parasympathetic nervous system. Here we used pupillometry in a novel attempt to uncover the distinct emotional response associated with a trypophobic response to holes. Across two experiments, images of holes elicited greater constriction compared to images of threatening animals and neutral images. Moreover, this effect held when controlling for level of arousal and accounting for the pupil grating response. This pattern of pupillary response is consistent with involvement of the parasympathetic nervous system and suggests a disgust, not a fear, response to images of holes. Although general aversion may be rooted in shared visual-spectral properties, we propose that the specific emotion is determined by cognitive appraisal of the distinct image content.