Serial processing of proximity groups and similarity groups

Proximity and feature similarity are two important determinants of perceptual grouping in vision. When viewing visual scenes conveying both grouping options simultaneously, people most usually detect proximity groups faster than similarity groups. This article demonstrates that perceptual judgments of grouping orientation guided by either proximity or contrast similarity are indicative of a sequential organization of grouping operations in the visual pathway, which lends a temporal processing advantage to proximity grouping (Experiment 1). Invoking the double-factorial paradigm, latent cognitive architecture for perceptual grouping is also investigated in a task with redundant signals (Experiment 2). Reaction time data from this task is assessed in terms of the race model inequality, workload capacity analysis, and interaction contrasts of means and survivor functions. Again, empirical benchmarks indicate serial processing of proximity groups and similarity groups, with a self-terminating stopping rule for processing. A subset of participants exhibit atypical performance metrics, hinting at possible individual differences in configural visual processing.