The pupillary response as an indicator of arousal and cognition

Infant and adult perceptions of possible and impossible body movements: An eye-tracking study

“…It is known that pupil size can be influenced by level of arousal or by cognitive load (Kahneman & Beatty, 1966;Libby et al, 1973;Tryon, 1975;Vo et al, 2008). Since ours was a passive viewing task that required no cognitive load, we interpret the change in pupil size as arousal (Bradley et al, 2008;Janisse, 1974;Partala & Surakka 2003;Stanners et al, 1979). Furthermore, Bradley et al (2008) reported that pupil dilation in response to arousing stimuli compared with neutral stimuli starts from about 2 s post stimulus onset.…”

“…This measure has recently been successfully employed in infant studies (Gredebäck & Melinder, 2010;Jackson & Sirois, 2009;Sirois & Jackson, 2012), although it has been used primarily to assess cognitive and affective information processing in adults (Kahneman & Beatty, 1966;Libby, Lacey, & Lacey, 1973;Tryon, 1975). Specifically, when cognitive load was minimal, pupils dilated to highly arousing stimuli, regardless of whether these were negative or positive (Bradley, Miccoli, Escrig, & Lang, 2008;Janisse, 1974;Partala & Surakka 2003;Stanners, Coulter, Sweet, & Murphy, 1979). In an unpublished preliminary study, we found that adults' pupils dilated more when they viewed impossible human arm movements than when they viewed possible ones, consistent with our work in which adults reported that viewing such stimuli was aversive (Morita et al, 2010).…”

Eye-Based Measures

“…Although there is little doubt that pupillary response is a useful measure of variations in cognitive load, pupillary response is also found to be sensitive to confounding (or noisy) factors unrelated to the cognitive task, such as changes of illumination and emotional states [6][7][8]. Kramer [9] reported that larger changes in the pupil diameter occur in response to illumination changes than during information processing.…”

Physiological heatmaps: a tool for visualizing users’ emotional reactions

“…However, research showed that variations in pupil diameter (PD) also respond significantly to cognitive and emotional stimuli [37,41,62]. Recent data suggests that the pupil's response is significantly modulated by emotional arousal regardless of hedonic valence [1,11].…”