fMRI studies of associative encoding in young and elderly controls and mild Alzheimer's disease.
OBJECTIVE
To examine alterations in patterns of brain activation seen in normal aging and in mild Alzheimer's disease by functional magnetic resonance imaging (fMRI) during an associative encoding task.


METHODS
10 young controls, 10 elderly controls, and seven patients with mild Alzheimer's disease were studied using fMRI during a face-name association encoding task. The fMRI paradigm used a block design with three conditions: novel face-name pairs, repeated face-name pairs, and visual fixation.


RESULTS
The young and elderly controls differed primarily in the pattern of activation seen in prefrontal and parietal cortices: elderly controls showed significantly less activation in both superior and inferior prefrontal cortices but greater activation in parietal regions than younger controls during the encoding of novel face-name pairs. Compared with elderly controls, the Alzheimer patients showed significantly less activation in the hippocampal formation but greater activation in the medial parietal and posterior cingulate regions.


CONCLUSIONS
The pattern of fMRI activation during the encoding of novel associations is differentially altered in the early stages of Alzheimer's disease compared with normal aging.
Sperling
R A
RA
Memory Disorders Unit, Department of Neurology, Brigham and Women's Hospital, 221 Longwood Avenue, Boston, MA 02115, USA. reisa@rics.bwh.harvard.edu
Bates
J F
JF
Chua
E F
EF
Cocchiarella
A J
AJ
Rentz
D M
DM
Rosen
B R
BR
Schacter
D L
DL
Albert
M S
MS
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000503:physiopathology*; D001244:Association; D001245:Association Learning; D001921:Brain / Q000473:pathology / Q000502:physiology / Q000503:physiopathology*; D001931:Brain Mapping; D005260:Female; D006624:Hippocampus / Q000473:pathology / Q000502:physiology / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D010775:Photic Stimulation; D011237:Predictive Value of Tests; D012016:Reference Values