Pattern separation and pattern completion in early childhood.

Pattern separation, or distinguishing similar experiences from one another, and pattern completion, in which components of an experience prompt retrieval or forgetting of an event pattern as a unit, are essential components of episodic memory. However, these two components are sometimes described as opposite ends of a continuum and sometimes described as independent processes. Here, we examined the relations between the two processes for the same events in children between 4 and 7 y. Mnemonic discrimination (the behavioral signature of pattern separation) improved with age; holistic recollection (the behavioral signature of pattern completion) did not change in this age range. Crucially, the two behaviors were unrelated, controlling for the effect of age, and even when examining their relations at the fine-grained level of memory for individual events.