Do categorical representations modulate early automatic visual processing? A visual mismatch-negativity study

Perceptual categorization is an important cognitive function. In the auditory domain, categorization already occurs within the first 200 ms of information processing, as indexed by the mismatch negativity. Here, we assessed the characteristics of the visual mismatch negativity (vMMN) elicited during the categorization of previously unknown visual stimuli. To examine this, we used five-dot patterns with characteristics that allow for the formation of categories through rotation and reflection but not through other physical properties. To assess whether or not between-category and within-category vMMN differ in amplitude, the data was analyzed with the Bayesian approach. We observed that both between-category and within-category deviants elicited a vMMN, but that both vMMNs were comparable in magnitude. This finding suggests that abstract categorical representations are not always automatically processed at early visual stages and demonstrates limitations of generalization from the auditory domain to visual domain.