Proceedings of the Annual Meeting of the Cognitive Science Society

Category learning is a core competence for minimizing cognitive load and optimizing decision-making. An identical problem can be solved by employing a rule-based or a similarity-based strategy. This work examined whether the use of the two strategies was supported by common or distinct neural substrates. We conducted a category learning experiment with rule-plus-similarity stimuli using EEG-fNIRS fusion methodology. Participants learned two artificial categories using either a rule-based or similarity-based strategy. The results showed a common visual-perceptual-analysis process and distinct decision-making processes between the uses of the two strategies. Larger P300 and N400 amplitudes and Wernicke's area activation indicated that hypotheses testing and verbal rule abstraction processes were critical for rule-based categorization. In contrast, increased frontopolar cortex activity indicated that integration of multiple dimensions was critical for similarity-based categorization. These results were consistent with COVIS theory, implying an explicit system in rule-based category learning whereas an implicit system in similarity-based learning.