title: Pupil diameter measurement errors as a function of gaze direction in corneal reflection eyetrackers.
abstract: Pupil dilation is a useful, noninvasive technique for measuring the change in cognitive load. Since it is implicit and nonverbal, it is particularly useful with preverbal or nonverbal participants. In cognitive psychology, pupil dilation is most often measured by corneal reflection eye-tracking devices. The present study investigates the effect of gaze position on pupil size estimation by three common eye-tracking systems. The task consisted of a simple object pursuit situation, as a sphere rotated around the display screen. Systematic errors of pupil size estimation were found with all three systems. Implications for task-elicited pupillometry, especially for gaze-contingent studies such as object tracking or reading, are discussed.
authors.affiliation: Université du Québec à Trois-Rivières, Psychologie, Trois-Rivieres, QC, Canada, julie_brisson@yahoo.fr.
authors.forename: Julie
authors.initials: J
authors.lastname: Brisson
authors.forename: Marc
authors.initials: M
authors.lastname: Mainville
authors.forename: Dominique
authors.initials: D
authors.lastname: Mailloux
authors.forename: Christelle
authors.initials: C
authors.lastname: Beaulieu
authors.forename: Josette
authors.initials: J
authors.lastname: Serres
authors.forename: Sylvain
authors.initials: S
authors.lastname: Sirois
mesh_terms: D000328:Adult; D003315:Cornea; D061827:Dimensional Measurement Accuracy; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D006801:Humans; D007498:Iris / Q000033:anatomy & histology*; D008297:Male; D008875:Middle Aged; D011680:Pupil / Q000502:physiology*; D011932:Reading; D012044:Regression Analysis; D055815:Young Adult