Can a Low-Cost Eye Tracker Assess the Impact of a Valent Stimulus? A Study Replicating the Visual Backward Masking Paradigm. Issue 2 (1st June 2020)

• Record Type: Journal Article
• Authors: Vlastos, Dimitris D; Kyritsis, Markos; Varela, Vasiliki-Alexia; Gulliver, Stephen R; Papaioannou-Spiroulia, Afroditi
• Is Part Of: Interacting with computers. Volume 32:Issue 2(2020)
• Page Start: 132
• Page End: 141
• Publication Date: 2020-06-01
• Subjects: backward masking -- evaluation tools -- eye-tracking -- pupil size, saccadic duration -- affective processing; Human-computer interaction -- Periodicals; 004.019
• DOI: 10.1093/iwc/iwaa010
• Languages: English
• ISSNs: 0953-5438

Abstract

Abstract: Capturing affective response to valent stimuli using eye tracking is of interest not only to academic research but also to commercial equipment developers (e.g. car dashboards). In order to investigate whether a low-cost eye tracker can effectively detect participants' physiological response to negatively valent stimuli, 44 participants aged 19–24 (mean = 24.7, SD = 5.8) were recruited to complete the visual backward masking paradigm in a repeated-measure experimental design. Saccadic duration and pupil sizes were recorded using a lower-end 60-Hz tracker. Data was analysed using a mix of parametric and non-parametric tests. Our results suggest that valence in the form of fearful vs neutral faces has a significant main effect on both saccadic duration [ V = 931, P < 0.001, d = 0.96] and pupil size [ t (43) = 29.81, P < 0.001, d = 3.91)]. Our findings were further supported by Bayes factor analysis, which showed that saccadic duration data was 24 times more likely to occur, and pupil size measurement data was 89 times more likely, under the alternative hypothesis, showing that differences in valence had a main effect. The combined evidence produced by our Bayesian analysis, the large effect sizes of our frequentist analysis and the significant effect on two separate measurements lead us to suggest that, under the right conditions, low-cost eye trackers can successfully detect changes in saccadic duration and pupil sizes as a result of physiological responses to threat-relevant visual stimuli.