Expanding and contracting optic-flow patterns and vection.
When stationary observers view an optic-flow pattern, visually induced self-motion perception (vection) and a form of motion sickness known as simulator sickness (SS), can result. Previous results suggest that an expanding flow pattern leads to more SS than a contracting pattern. Sensory conflict, a possible cause of SS, may be more salient when an expanding optic-flow pattern is viewed. An experiment was conducted to test if a more salient sensory conflict accompanying expanding flow patterns might inhibit vection. Participants (n = 15) viewed a pattern of blue squares, either steadily expanded or contracted, on a large rear-projection screen. Vection onset and magnitude were measured for 30 s with a computer-interfaced slide device. Vection onset was significantly faster, and vection magnitude stronger, when a contracting pattern was viewed. We propose that our extensive experience with forward self-motion may form a neural expectancy (exposure-history) about the sensory inputs which typically accompany expanding flow. However, since backward self-motion is less common, there may be a weaker exposure-history for contracting flow, and as a result these patterns generate less salient sensory conflict and subsequently less vection.
Bubka
Andrea
A
Department of Psychology, Saint Peter's College, Jersey City, NJ 07306, USA.
Bonato
Frederick
F
Palmisano
Stephen
S
D000293:Adolescent; D000328:Adult; D003867:Depth Perception / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009039:Motion Perception / Q000502:physiology*; D009041:Motion Sickness / Q000209:etiology; D009949:Orientation / Q000502:physiology*; D010775:Photic Stimulation / Q000009:adverse effects; D011434:Proprioception / Q000502:physiology; D012399:Rotation / Q000009:adverse effects; D011795:Surveys and Questionnaires; D014785:Vision, Ocular / Q000502:physiology