title: Jitter and size effects on vection are immune to experimental instructions and demands.
abstract: Both coherent perspective jitter and explicit changing-size cues have been shown to improve the vection induced by radially expanding optic flow. We examined whether these stimulus-based vection advantages could be modified by altering cognitions and/or expectations about both the likelihood of self-motion perception and the purpose of the experiment. In the main experiment, participants were randomly assigned into two groups-one where the cognitive conditions biased participants towards self-motion perception and another where the cognitive conditions biased them towards object-motion perception. Contrary to earlier findings by Lepecq et al (1995 Perception 24 435-449), we found that identical visual displays were less likely to induce vection in 'object-motion-bias' conditions than in 'self-motion bias' conditions. However, significant jitter and size advantages for vection were still found in both cognitive conditions (cognitive bias effects were greatest for non-jittering same-size control displays). The current results suggest that if a sufficiently large vection advantage can be produced when participants are expecting to experience self-motion, it is likely to persist in object-motion-bias conditions.
authors.affiliation: Department of Psychology, University of Wollongong, Wollongong, NSW 2522, Australia. Stephenp@uow.edu.au
authors.forename: Stephen
authors.initials: S
authors.lastname: Palmisano
authors.forename: Amy Y C
authors.initials: AY
authors.lastname: Chan
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D003071:Cognition / Q000502:physiology*; D003463:Cues; D005260:Female; D006801:Humans; D007699:Kinesthesis / Q000502:physiology*; D008297:Male; D009039:Motion Perception / Q000502:physiology; D009483:Neuropsychological Tests; D012858:Size Perception / Q000502:physiology