title: Pupil Sizes Scale with Attentional Load and Task Experience in a Multiple Object Tracking Task.
abstract: Previous studies have related changes in attentional load to pupil size modulations. However, studies relating changes in attentional load and task experience on a finer scale to pupil size modulations are scarce. Here, we investigated how these changes affect pupil sizes. To manipulate attentional load, participants covertly tracked between zero and five objects among several randomly moving objects on a computer screen. To investigate effects of task experience, the experiment was conducted on three consecutive days. We found that pupil sizes increased with each increment in attentional load. Across days, we found systematic pupil size reductions. We compared the model fit for predicting pupil size modulations using attentional load, task experience, and task performance as predictors. We found that a model which included attentional load and task experience as predictors had the best model fit while adding performance as a predictor to this model reduced the overall model fit. Overall, results suggest that pupillometry provides a viable metric for precisely assessing attentional load and task experience in visuospatial tasks.
authors.affiliation: Institute of Cognitive Science, University of Osnabrück, Osnabrück, Germany.
authors.forename: Basil
authors.initials: B
authors.lastname: Wahn
authors.affiliation: Human Neuromechanics Laboratory, School of Kinesiology, University of Michigan - Ann Arbor, MI, United States of America.
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Ferris
authors.affiliation: Human Research and Engineering Directorate, U.S. Army Research Laboratory, Aberdeen, MD, United States of America.
authors.forename: W David
authors.initials: WD
authors.lastname: Hairston
authors.affiliation: Institute of Cognitive Science, University of Osnabrück, Osnabrück, Germany.|Department of Neurophysiology and Pathophysiology, Center of Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: König
mesh_terms: D000293:Adolescent; D000328:Adult; D001288:Attention / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D011680:Pupil / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult