PT - JOURNAL ARTICLE AU - Eldridge, Laura L. AU - Engel, Stephen A. AU - Zeineh, Michael M. AU - Bookheimer, Susan Y. AU - Knowlton, Barbara J. TI - A Dissociation of Encoding and Retrieval Processes in the Human Hippocampus AID - 10.1523/JNEUROSCI.3420-04.2005 DP - 2005 Mar 30 TA - The Journal of Neuroscience PG - 3280--3286 VI - 25 IP - 13 4099 - http://www.jneurosci.org/content/25/13/3280.short 4100 - http://www.jneurosci.org/content/25/13/3280.full SO - J. Neurosci.2005 Mar 30; 25 AB - 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.