Perceptual grouping in Gabor lattices: proximity and alignment.

We propose the Gabor lattice as a new stimulus designed to deal with multiple organizations in perceptual grouping, allowing both comparison between psychophysical data and neural findings and a systematic investigation of grouping based on several low-level characteristics and their interactions. A Gabor lattice is a geometric lattice with Gabor patches, evoking a multistable global orientation percept. Visual grouping in Gabor lattices with elements aligned in a global orientation was compared with grouping of nonaligned Gabor patches and of Gaussian blobs. The effect sizes of proximity and alignment were estimated in logistic regression analyses. The results confirmed the importance of proximity and local element alignment as factors in dynamic grouping. We also found a small but consistent enhancement of grouping along the global vector orthogonal to the local patch orientations. In light of these results, we further motivate the relevance of these stimuli and the associated experimental paradigm.