Visual mismatch negativity and categorization.

Visual mismatch negativity (vMMN) component of event-related potentials is elicited by stimuli violating the category rule of stimulus sequences, even if such stimuli are outside the focus of attention. Category-related vMMN emerges to colors, and color-related vMMN is sensitive to language-related effects. A higher-order perceptual category, bilateral symmetry is also represented in the memory processes underlying vMMN. As a relatively large body of research shows, violating the emotional category of human faces elicits vMMN. Another face-related category sensitive to the violation of regular presentation is gender. Finally, vMMN was elicited to the laterality of hands. As results on category-related vMMN show, stimulus representation in the non-conscious change detection system is fairly complex, and it is not restricted to the registration of elementary perceptual regularities.