title: Multiple-location access in vision: evidence from illusory line motion.
abstract: Four experiments with undergraduates used illusory line motion (ILM) to contrast Z. W. Pylyshyn's (1989) FINST theory of spatial indexing with predictions made by unitary attention models. Multiple-onset stimuli were able to cause ILM at disparate, noncontiguous spatial locations. Consistent with gradient explanations of ILM and with FINST theory predictions, varying line-drawing speed and the number of stimuli revealed a decrease in ILM and a capacity limitation, respectively. Modeling analyses suggested a limit in the number of locations (5-7) that could elicit the illusion. Requiring participants to report the locations of all stimuli exhibiting illusory motion in a specified direction suggested parallel access to between 2 and 5 display locations simultaneously. The results of all 4 experiments were predicted by FINST theory but not by a broad class of unitary attention hypotheses.
authors.affiliation: Department of Psychology, Dalhousie University, Halifax, Nova Scotia, Canada. wcs@or.psychology.dal.ca
authors.forename: W C
authors.initials: WC
authors.lastname: Schmidt
authors.forename: B D
authors.initials: BD
authors.lastname: Fisher
authors.forename: Z W
authors.initials: ZW
authors.lastname: Pylyshyn
mesh_terms: D000054:Acceleration; D000328:Adult; D001288:Attention; D015350:Contrast Sensitivity; D004193:Discrimination Learning; D005260:Female; D006801:Humans; D008297:Male; D009039:Motion Perception; D009903:Optical Illusions; D009949:Orientation; D010364:Pattern Recognition, Visual; D011601:Psychophysics; D013334:Students / Q000523:psychology