How temporal frequency affects global form coherence in Glass patterns

•Dynamic (i.e. sequentially presented) Glass patterns induce illusory motion.•Temporal frequency improved form coherence thresholds linearly.•Form coherence thresholds worsened with increasing dot pair separation.•Dynamic presentations especially lowered thresholds of patterns at large separations.

Glass patterns are textural moirés from random dots. Sequential presentation of Glass patterns induces a sense of illusory motion. We evaluated how changes in temporal frequency affected the detection of global form in Glass patterns. We found linear improvement in coherence thresholds with increasing temporal frequency (Experiment 1), particularly in stimuli with large dot-pair separations (Experiment 2). These results support the notion that temporal and orientation information sum to boost sensitivity to visually obscure objects, and are discussed within the framework of “motion streak” detectors.