Humans build internal models of the environment to make predictions. For example, after a regular pattern of auditory tones has been presented, phasic arousal and pupil dilation responses (PDRs) are induced when the regularity is then violated. This suggests that an internal model of the regularity is first constructed and then reset. In contrast, the emergence of a regular pattern from a random pattern does not elicit these responses. These findings have been extensively studied for the case of auditory patterns (Zhao et al., Nature Communications, 2019; Basgol, Psychonomics-conference, 2022). Here, we investigated whether they generalize to spatiotemporal visual patterns. We presented regular or random patterns of white dots appearing at different locations on a grid. We used (a) transitions from a regular pattern to a random or another regular pattern (both violating the earlier regularity) or (b) transitions from a random to a regular pattern (such that a regularity emerges). Participants (N=14) were instructed to find blanks in the patterns to keep their attention. Similar to auditory patterns, violations of visual regularities evoked PDRs (albeit with smaller magnitudes), while the emergence of a regularity did not evoke PDRs. Our findings suggest that violations of visual regularities, but not their emergence, lead to arousal and PDRs— just as for auditory regularities.

Supported by German Research Foundation (DFG): SFB 1233, Robust Vision: Inference Principles and Neural Mechanisms, TP 05, No 276693517, Max Planck Society and Humboldt Foundation (PD), and Machine Learning Cluster of Excellence, EXC 2064/1 No 390727645 (VF).