Effects of global atrophy, white matter lesions, and cerebral blood flow on age-related changes in speed, memory, intelligence, vocabulary, and frontal function.
Brain images were obtained from 133 healthy people of ages 61-85 years who completed 20 tests of information processing speed, intelligence, frontal and executive function, memory, and vocabulary. Structural equation models examined relationships between cognitive test scores, ages and measurements of global age-associated atrophy, white matter lesions, and cerebral blood flow. These neurophysiological measures jointly account for all age-related variance in information processing speed. Speed entirely mediated relationships between neurophysiological measures and memory and partly mediated relationships between neurophysiological measures and intelligence and frontal function. Neurophysiological measures, but not calendar age, accounted for vocabulary scores. Cognitive slowing was responsible for some, but not all, age-related declines in mental function. Age-related declines in intelligence, frontal function, and speed were due to changes in different functional systems.
Rabbitt
Patrick
P
Department of Experimental Psychology, University of Oxford, England. patrick.rabbitt@psy.ox.ac.uk
Mogapi
Oemetse
O
Scott
Marietta
M
Thacker
Neil
N
Lowe
Christine
C
Horan
Mike
M
Pendleton
Neil
N
Jackson
Alan
A
Lunn
Dan
D
D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology* / Q000502:physiology*; D001284:Atrophy; D001921:Brain / Q000473:pathology*; D002560:Cerebrovascular Circulation / Q000502:physiology; D005260:Female; D006801:Humans; D007360:Intelligence / Q000502:physiology*; D008297:Male; D008568:Memory / Q000502:physiology*; D008606:Mental Processes / Q000502:physiology*; D008875:Middle Aged; D008954:Models, Biological; D009483:Neuropsychological Tests / Q000706:statistics & numerical data