Dissociations in hippocampal and frontal contributions to episodic memory performance.
The hippocampus and frontal lobes both contribute to episodic memory performance. In the present study, the authors evaluated the relative contributions of hippocampus, frontal lobes, anterior temporal cortex, and posterior cortex to memory performance in neurodegenerative patients and normal older controls. Subjects (n=42) were studied with structural MRI and a memory paradigm that measured delayed recall, semantic clustering during recall, recognition discriminability, and recognition response bias. Data were analyzed with multiple regression. Consistent with the authors' hypotheses, hippocampal volumes were the best predictor of delayed recall and recognition discriminability, whereas frontal volumes were the best predictor of semantic clustering and response bias. Smaller frontal volumes were associated with less semantic clustering during recall and a more liberal response bias. Results indicate that hippocampal and frontal contributions to episodic memory can be dissociated, with the hippocampus more important for memory accuracy, and frontal structures more important for strategic processing and decision making.
Kramer
Joel H
JH
Department of Neurology, University of California, San Francisco Medical Center, San Francisco, CA 94143, USA. kramer@itsa.ucsf.edu
Rosen
Howard J
HJ
Du
An-Tao
AT
Schuff
Norbert
N
Hollnagel
Caroline
C
Weiner
Michael W
MW
Miller
Bruce L
BL
Delis
Dean C
DC
D000368:Aged; D016022:Case-Control Studies; D005260:Female; D005625:Frontal Lobe / Q000473:pathology / Q000503:physiopathology*; D006624:Hippocampus / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008569:Memory Disorders / Q000209:etiology*; D011939:Mental Recall / Q000502:physiology; D008875:Middle Aged; D019636:Neurodegenerative Diseases / Q000473:pathology / Q000503:physiopathology*; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D011237:Predictive Value of Tests