title: Perception and reconstruction of two-dimensional, simulated ego-motion trajectories from optic flow. creator: Bertin, R.J.V. creator: Israël, I. creator: Lappe, M. subject: Psychophysics description: A veridical percept of ego-motion is normally derived from a combination of visual, vestibular, and proprioceptive signals. In a previous study, blindfolded subjects could accurately perceive passively travelled straight or curved trajectories provided that the orientation of the head remained constant along the trajectory. When they were turned (whole-body, head-fixed) relative to the trajectory, errors occurred. We ask here whether vision allows for better path perception in similar tasks, to correct or complement vestibular perception. Seated, stationary subjects wore a head mounted display showing optic flow stimuli which simulated linear or curvilinear 2D trajectories over a horizontal ground plane. The observer's orientation was either fixed in space, fixed relative to the path, or changed relative to both. After presentation, subjects reproduced the perceived movement with a model vehicle, of which position and orientation were recorded. They tended to correctly perceive ego-rotation (yaw), but they perceived orientation as fixed relative to trajectory or (unlike in the vestibular study) to space. This caused trajectory misperception when body rotation was wrongly attributed to a rotation of the path. Visual perception was very similar to vestibular perception. date: 2000 type: Journal (Paginated) type: PeerReviewed format: application/pdf identifier: http://cogprints.org/2120/2/VR-2000-40-21-P2951-RE.PDF identifier: Bertin, R.J.V. and Israël, I. and Lappe, M. (2000) Perception and reconstruction of two-dimensional, simulated ego-motion trajectories from optic flow. [Journal (Paginated)] relation: http://cogprints.org/2120/