The neural correlates of similarity- and rule-based generalization
Journal of Cognitive Neuroscience
Massachusetts Institute of Technology Press (MIT Press)
This is the author accepted manuscript. The final version is available from MIT Press via the DOI in this record.
Reason for embargo
The idea that there are multiple learning systems has become increasingly influential in recent years with many studies providing evidence that there is both a quick, similarity, or feature-based, system, and a more effortful, rule-based system. A smaller number of imaging studies have also examined whether neurally dissociable learning systems are detectable. We further investigate this by employing for the first time in an imaging study a combined positive and negative patterning procedure originally developed by Shanks and Darby (1998). Unlike previous related studies employing other procedures, rule generalization in the Shanks-Darby task is beyond any simple non-rule-based (e.g., associative) account. We found that rule- and similarity-based generalization evoked common activation in diverse regions including the prefrontal cortex and the bilateral parietal and occipital lobes indicating that both strategies likely share a range of common processes. No differences between strategies were identified in whole-brain comparisons but exploratory analyses indicated that rule-based generalization led to greater activation in the right middle frontal cortex than similarity-based generalization. Conversely, the similarity group activated the anterior medial frontal lobe and right inferior parietal lobes more than the rule group did. The implications of these results are discussed.
Posted Online August 30, 2016