title: Occlusion, symmetry, and object-based attention: comment on Behrmann, Zemel, and Mozer (1998).
abstract: The validity of M. Behrmann, R. Zemel, and M. Mozer's (1998) finding that object-based attention can be directed toward occluded objects is examined in 3 experiments. In M. Behrmann et al.'s (1998) original study, participants made speeded judgments of whether the numbers of bumps attached to 2 arms of an X shape were the same or different. The 2 sets of bumps belonged either to a single object, 2 different objects, or 2 separated parts of an occluded object. Unfortunately, this objecthood manipulation was confounded by the symmetry of the stimuli. Experiment 1 replicated M. Behrmann et al.'s main results using identical stimuli. Experiments 2a and 2b dissociated objecthood from symmetry. The results suggest that the effects of object-based attention found by M. Behrmann et al. are largely due to symmetry. The stimuli used in M. Behrmann et al. are not appropriate for examining the relation between object-based attention and occlusion.
authors.affiliation: Graduate School of Human Informatics, Nagoya University, Japan. saiki@cog.human.nagoya-u.ac.jp
authors.forename: J
authors.initials: J
authors.lastname: Saiki
mesh_terms: D000328:Adult; D001288:Attention; D015986:Confounding Factors, Epidemiologic; D005260:Female; D005556:Form Perception; D006801:Humans; D008297:Male; D008960:Models, Psychological; D010364:Pattern Recognition, Visual; D011597:Psychomotor Performance; D011930:Reaction Time; D013997:Time Factors