title: Eye Movements in Darkness Modulate Self-Motion Perception.
abstract: During self-motion, humans typically move the eyes to maintain fixation on the stationary environment around them. These eye movements could in principle be used to estimate self-motion, but their impact on perception is unknown. We had participants judge self-motion during different eye-movement conditions in the absence of full-field optic flow. In a two-alternative forced choice task, participants indicated whether the second of two successive passive lateral whole-body translations was longer or shorter than the first. This task was used in two experiments. In the first (n= 8), eye movements were constrained differently in the two translation intervals by presenting either a world-fixed or body-fixed fixation point or no fixation point at all (allowing free gaze). Results show that perceived translations were shorter with a body-fixed than a world-fixed fixation point. A linear model indicated that eye-movement signals received a weight of ∼25% for the self-motion percept. This model was independently validated in the trials without a fixation point (free gaze). In the second experiment (n= 10), gaze was free during both translation intervals. Results show that the translation with the larger eye-movement excursion was judged more often to be larger than chance, based on an oculomotor choice probability analysis. We conclude that eye-movement signals influence self-motion perception, even in the absence of visual stimulation.
authors.affiliation: Donders Institute for Brain, Cognition, and Behaviour, Radboud University Nijmegen , 6525 HR, Nijmegen, The Netherlands.
authors.forename: Ivar Adrianus H
authors.identifier: 0000-0001-6531-0948
authors.initials: IA
authors.lastname: Clemens
authors.affiliation: Donders Institute for Brain, Cognition, and Behaviour, Radboud University Nijmegen , 6525 HR, Nijmegen, The Netherlands.
authors.forename: Luc P J
authors.identifier: 0000-0001-5774-5415
authors.initials: LP
authors.lastname: Selen
authors.affiliation: Donders Institute for Brain, Cognition, and Behaviour, Radboud University Nijmegen , 6525 HR, Nijmegen, The Netherlands.
authors.forename: Antonella
authors.initials: A
authors.lastname: Pomante
authors.affiliation: German Center for Vertigo and Balance Disorders, Ludwig Maximillians University Hospital of Munich , D-81377 Munich, Germany.
authors.forename: Paul R
authors.identifier: 0000-0001-6364-8494
authors.initials: PR
authors.lastname: MacNeilage
authors.affiliation: Donders Institute for Brain, Cognition, and Behaviour, Radboud University Nijmegen , 6525 HR, Nijmegen, The Netherlands.
authors.forename: W Pieter
authors.identifier: 0000-0001-9615-4220
authors.initials: WP
authors.lastname: Medendorp
mesh_terms: D000328:Adult; D002755:Choice Behavior; D003624:Darkness; D053483:Eye Movement Measurements; D005133:Eye Movements; D005260:Female; D006801:Humans; D008297:Male; D008954:Models, Biological; D009039:Motion Perception; D011434:Proprioception; D011594:Psychometrics; D011601:Psychophysics; D013998:Time Perception; D055815:Young Adult
keywords: integration; oculomotor; perception; self-motion; vestibular 