TY - JOUR T1 - A roadmap for understanding memory: Decomposing cognitive processes into operations and representations JF - eneuro JO - eNeuro DO - 10.1523/ENEURO.0122-19.2019 SP - ENEURO.0122-19.2019 AU - Rosemary A. Cowell AU - Morgan D. Barense AU - Patrick S. Sadil Y1 - 2019/06/12 UR - http://www.eneuro.org/content/early/2019/06/12/ENEURO.0122-19.2019.abstract N2 - Thanks to patients Phineas Gage and Henry Molaison, we have long known that behavioral control depends on the frontal lobes, whereas declarative memory depends on the medial temporal lobes (MTL). For decades, cognitive functions – behavioral control, declarative memory – have served as labels for characterizing the division of labor in cortex. This approach has made enormous contributions to understanding how the brain enables the mind, providing a systems-level explanation of brain function that constrains lower-level investigations of neural mechanism. Today, the approach has evolved such that functional labels are often applied to brain networks rather than focal brain regions. Furthermore, the labels have diversified to include both broadly-defined cognitive functions (declarative memory, visual perception) and more circumscribed mental processes (recollection, familiarity, priming). We ask whether a process – a high-level mental phenomenon corresponding to an introspectively-identifiable cognitive event – is the most productive label for dissecting memory. For example, recollection conflates a neurocomputational operation (pattern completion-based retrieval) with a class of representational content (associative, high-dimensional memories). Because a full theory of memory must identify operations and representations separately, and specify how they interact, we argue that processes like recollection constitute inadequate labels for characterizing neural mechanisms. Instead, we advocate considering the component operations and representations of processes like recollection in isolation. For the organization of memory, the evidence suggests that pattern completion is recapitulated widely across the ventral visual stream and MTL, but the division of labor between sites within this pathway can be explained by representational content.Significance Statement Accounts of cognition often assume that the brain is organized along lines of cognitive process, for example, with recollection mediated by one neural structure and familiarity by another. We argue that cognitive processes – introspectively-identifiable mental events like recollection – are inadequate labels for characterizing neural mechanisms, because they conflate lower-level components of the mechanisms we seek to identify. Recollection involves both a neurocomputational operation (pattern completion) and a neural representation (high-dimensional, associative content). To uncover memory's mechanisms, we must decompose memory processes into their operations and representations, asking how each contributes to mnemonic phenomena. Decomposing recollection suggests that, within the ventral visual pathway and MTL, different brain regions contribute to memory retrieval according to their representational content. ER -