title: Interactions between constituent single symmetries in multiple symmetry.
abstract: As a rule, the discriminability of multiple symmetries from random patterns increases with the number of symmetry axes, but this number does not seem to be the only determinant. In particular, multiple symmetries with orthogonal axes seem better discriminable than multiple symmetries with nonorthogonal axes. In six experiments on imperfect two-fold symmetry, we investigated whether this is due to extra structure in the form of so-called correlation rectangles, which arise only in the case of orthogonal axes, or to the relative orientation of the axes as such. The results suggest that correlation rectangles are not perceptually relevant and that the percept of a multiple symmetry results from an orientation-dependent interaction between the constituent single symmetries. The results can be accounted for by a model involving the analysis of symmetry at all orientations, smoothing (averaging over neighboring orientations), and extraction of peaks.
authors: Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands. matthias.treder@tu-berlin.de
authors: Matthias Sebastian
authors: MS
authors: Treder
authors: Gert
authors: G
authors: van der Vloed
authors: Peter A
authors: PA
authors: van der Helm
mesh_terms: D001288:Attention; D004192:Discrimination, Psychological; D005364:Field Dependence-Independence; D006801:Humans; D009949:Orientation; D010364:Pattern Recognition, Visual; D011601:Psychophysics; D013223:Statistics as Topic