A reappraisal of the function of episodic memory

Abstract

This paper defends the mnemonic hypothesis regarding the evolutionary function of episodic memory. According to this view, episodic memory evolved to accurately store and process information about particular past events in order to support its accurate retrieval. Crucially, this information includes the representation of spatiotemporal relations within and among these events. My analysis is grounded in an evolutionary notion of function, which I clarify at the beginning of the paper. I also discuss the types of evidence I will use to evaluate hypotheses about the evolutionary function of a cognitive system. In particular, I focus on four sources of evidence that are typically used in such evaluations: (1) causal-role functional analysis, (2) dysfunctional states, (3) reverse inference from optimality models, and (4) evidence against alternative hypotheses, which in this case are non-mnemonic hypotheses. I argue that the first three types of evidence converge in support of the mnemonic hypothesis. I then critically examine prominent competing accounts, including the imagining-the-future, the counterfactual-thought, the predictive processing, and the universal learning hypotheses. I argue that these alternatives are either inadequately supported by empirical data or are based on conceptual or methodological misunderstandings.