Similarity is associated with where repeated-event memories fall on the semantic–episodic continuum

Memories of repeated events are one form of memory thought to be intermediate on a proposed semantic-episodic continuum. However, it is not yet understood where repeated-event memories fall on this continuum, and which factors may be associated with greater or lesser reliance on episodic and semantic memory during recall. We investigated similarity amongst instances of repeated events as one factor which may be associated with where repeated events fall on the semantic-episodic continuum. In two preregistered studies, we asked participants to recall three repeated-event memories from their own lives (N₁ = 97 participants, 291 memories; N₂ = 419 participants, 1,257 memories) and report on the similarity amongst instances as well as the degree to which they relied on semantic memory, a single episode, and a mix of episodes in their recall of each event. In line with our predictions, similarity was positively correlated with reliance on semantic memory in both studies. In Study 2, similarity was negatively correlated with reliance on a single episode. We also conducted exploratory latent profile analyses using our three memory reliance variables, revealing three types of repeated-event memories. In both studies, similarity of place and emotional arousal were each associated with different memory profiles. Our findings highlight the importance of considering similarity in basic and applied repeated-event memory research, as different conditions of similarity (e.g., low vs. high) can manifest in different patterns of reliance on episodic and semantic memory.