Scientific article
OA Policy
English

Motion integration is anisotropic during smooth pursuit eye movements

Published inJournal of neurophysiology, vol. 121, no. 5, p. 1787-1797
Publication date2019-05-01
Abstract

Smooth pursuit eye movements (pursuit) are used to minimize the retinal motion of moving objects. During pursuit, the pattern of motion on the retina carries not only information about the object movement but also reafferent information about the eye movement itself. The latter arises from the retinal flow of the stationary world in the direction opposite to the eye movement. To extract the global direction of motion of the tracked object and stationary world, the visual system needs to integrate ambiguous local motion measurements (i.e., the aperture problem). Unlike the tracked object, the stationary world's global motion is entirely determined by the eye movement and thus can be approximately derived from motor commands sent to the eye (i.e., from an efference copy). Because retinal motion opposite to the eye movement is dominant during pursuit, different motion integration mechanisms might be used for retinal motion in the same direction and opposite to pursuit. To investigate motion integration during pursuit, we tested direction discrimination of a brief change in global object motion. The global motion stimulus was a circular array of small static apertures within which one-dimensional gratings moved. We found increased coherence thresholds and a qualitatively different reflexive ocular tracking for global motion opposite to pursuit. Both effects suggest reduced sampling of motion opposite to pursuit, which results in an impaired ability to extract coherence in motion signals in the reafferent direction. We suggest that anisotropic motion integration is an adaptation to asymmetric retinal motion patterns experienced during pursuit eye movements.

NEW & NOTEWORTHY This study provides a new understanding of how the visual system achieves coherent perception of an object's motion while the eyes themselves are moving. The visual system integrates local motion measurements to create a coherent percept of object motion. An analysis of perceptual judgments and reflexive eye movements to a brief change in an object's global motion confirms that the visual and oculomotor systems pick fewer samples to extract global motion opposite to the eye movement.

Keywords
  • Motion perception
  • Ocular following
  • Perceptual integration
  • Smooth pursuit eye movement
Research groups
Funding
  • UK Research and Innovation - New pathways to hearing: A multisensory noise reducing and palate based sensory substitution device for speech perception [EP/M026965/1]
  • FNRS - [100014135374]
Citation (ISO format)
SOUTO, David et al. Motion integration is anisotropic during smooth pursuit eye movements. In: Journal of neurophysiology, 2019, vol. 121, n° 5, p. 1787–1797. doi: 10.1152/jn.00591.2018
Main files (2)
Article (Accepted version)
accessLevelPublic
Article (Published version)
Identifiers
Journal ISSN0022-3077
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Technical informations

Creation04/27/2022 1:40:00 PM
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