Pattern completion and the medial temporal lobe memory system

Pattern completion is a mechanism that allows us to infer a whole unit based on partial information. Memory theorists have posited that hippocampal pattern completion underlies recollection of episodic memories. To provide an introduction to hippocampal pattern completion and to illustrate the current state of research, we first address its psychological conceptualization for recollection and then outline the neuroanatomy and computational models of the hippocampal circuitry relevant for pattern completion. We further review neurophysiological investigations in rodents and studies on hippocampal pattern completion in humans. Finally, we discuss unresolved conceptual issues and open questions regarding the role of hippocampal pattern completion within and beyond episodic memory.