TY - GEN ID - cogprints2120 UR - http://cogprints.org/2120/ A1 - Bertin, R.J.V. A1 - Israël, I. A1 - Lappe, M. Y1 - 2000/// N2 - 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. KW - path perception KW - ego-motion; optic flow; linear heading KW - circular heading KW - vision; vestibular. TI - Perception and reconstruction of two-dimensional, simulated ego-motion trajectories from optic flow. SP - 2951 AV - public EP - 2971 ER -