A dissociation of encoding and retrieval processes in the human hippocampus.

TitleA dissociation of encoding and retrieval processes in the human hippocampus.
Publication TypeJournal Article
Year of Publication2005
AuthorsEldridge, LL, Engel SA, Zeineh MM, Bookheimer SY, Knowlton BJ
JournalThe Journal of neuroscience : the official journal of the Society for Neuroscience
Date Published2005 Mar 30
KeywordsAdult, Analysis of Variance, Brain Mapping, Evoked Potentials, Functional Laterality, Hippocampus, Humans, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, Mental Recall, Nerve Net, Neural Pathways, Recognition (Psychology), Time Factors

The hippocampal formation performs two related but distinct memory functions: encoding of novel information and retrieval of episodes. Little evidence, however, resolves how these two processes are implemented within the same anatomical structure. Here we use high-resolution functional magnetic resonance imaging to show that distinct subregions of the hippocampus are differentially involved in encoding and retrieval. We found that regions early in the hippocampal circuit (dentate gyrus and CA fields 2 and 3) were selectively active during episodic memory formation, whereas a region later in the circuit (the subiculum) was active during the recollection of the learning episode. Different components of the hippocampal circuit likely contribute to different degrees to the two basic memory functions.

Alternate JournalJ. Neurosci.