title: Memory in the aging brain: doubly dissociating the contribution of the hippocampus and entorhinal cortex.
abstract: Since the time of Aristotle it has been thought that memories can be divided into two basic types; conscious recollections and familiarity-based judgments. Neuropsychological studies have provided indirect support for this distinction by suggesting that different regions within the human medial temporal lobe (MTL) are involved in these two forms of memory, but none of these studies have demonstrated that these brain regions can be fully dissociated. In a group of nondemented elderly subjects, we found that performance on recall and recognition tests was predicted preferentially by hippocampal and entorhinal volumes, respectively. Structural equation modeling revealed a double dissociation, whereby age-related reductions in hippocampal volume resulted in decreases in recollection, but not familiarity, whereas entorhinal volume was preferentially related to familiarity. The results demonstrate that the forms of episodic memory supported by the human hippocampus and entorhinal cortex can be fully dissociated, and indicate that recollection and familiarity reflect neuroanatomically distinct memory processes.
authors.affiliation: Department of Psychology, University of California, Davis, California 95616, USA. apyonelinas@ucdavis.edu
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Yonelinas
authors.forename: Keith
authors.initials: K
authors.lastname: Widaman
authors.forename: Dan
authors.initials: D
authors.lastname: Mungas
authors.forename: Bruce
authors.initials: B
authors.lastname: Reed
authors.forename: Michael W
authors.initials: MW
authors.lastname: Weiner
authors.forename: Helena C
authors.initials: HC
authors.lastname: Chui
mesh_terms: D000368:Aged; D000375:Aging / Q000523:psychology*; D001921:Brain / Q000033:anatomy & histology / Q000254:growth & development* / Q000502:physiology*; D003463:Cues; D018728:Entorhinal Cortex / Q000033:anatomy & histology / Q000254:growth & development* / Q000502:physiology*; D005260:Female; D006624:Hippocampus / Q000033:anatomy & histology / Q000254:growth & development* / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000502:physiology*; D011939:Mental Recall / Q000502:physiology; D008875:Middle Aged; D008959:Models, Neurological; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000502:physiology; D021641:Recognition, Psychology / Q000502:physiology; D013702:Temporal Lobe / Q000033:anatomy & histology / Q000254:growth & development / Q000502:physiology