title: Detection of (anti)symmetry and (anti)repetition: perceptual mechanisms versus cognitive strategies.
abstract: Symmetry and repetition are recognized as cues in perceptual organization, but there is disagreement on whether they are detected automatically. This disagreement is resolved by noting that some studies mixed up shape regularities and shape antiregularities (i.e., symmetries and repetitions with mismatches in contour curvature polarity). The results of two experiments indicate that a task-irrelevant regularity is automatically picked up by the visual system, whereas a task-irrelevant antiregularity is not. This suggests that detection of regularities is part of the visual system's intrinsic encoding, whereas detection of antiregularities requires higher cognitive strategies involving selective attention.
authors.affiliation: Radboud University Nijmegen, Donders Institute for Brain, Cognition, and Behaviour, Montessorilaan 3, 6525 HR Nijmegen, The Netherlands. p.vanderhelm@donders.ru.nl
authors.forename: Peter A
authors.initials: PA
authors.lastname: van der Helm
authors.forename: Matthias S
authors.initials: MS
authors.lastname: Treder
mesh_terms: D001288:Attention / Q000502:physiology*; D003463:Cues; D004193:Discrimination Learning / Q000502:physiology; D006801:Humans; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D011601:Psychophysics; D011930:Reaction Time / Q000502:physiology; D055815:Young Adult