Parity is one source of automatic reinforcement that increases the probability of verbal behavior that conforms to models provided by the verbal community. Parity as a conditioned reinforcer could explain the acquisition of grammar in the absence of direct, explicit reinforcement. This possibility has been explored in previous research on…

Stimuli that capture the central tendency of presented exemplars are often preferred--a phenomenon also known as the classic beauty-in-averageness effect. However, recent studies have shown that this effect can reverse under certain conditions. We propose that a key variable for such ugliness-in-averageness effects is the category structure of the…

Recent fMRI studies have found that distinct neural systems may mediate perceptual category learning under implicit and explicit learning conditions. In these previous studies, however, different stimulus-encoding processes may have been associated with implicit versus explicit learning. The present design was aimed at decoupling the influence of…