Typicality in the brain during semantic and episodic memory decisions

Typicality is a key semantic dimension supporting the categorical organization of items based on their features. Typical items share more features with other members of their category than atypical items, which are more distinctive. Typicality influences episodic recollection. Yet, the neural substrates of this effect have never been studied. This fMRI study investigated the neural correlates of typicality during semantic and episodic memory decisions . 26 subjects performed a categorization task on typical and atypical word concept and completed a recognition memory task. During the correct recognition of old items, regions from the core recollection network were activated, and typical items were reinstated more than atypical ones in several regions including the anterior temporal lobe. Results suggest that the centrality of this region in the processing of typicality extends to memory retrieval, and that the correct retrieval of typical items requires finer-grained, item-specific, processing, possibly to resolve their greater confusability with other category members.</p>