Predicting conversion to dementia of the Alzheimer's type in a healthy control sample: the power of errors in Stroop color naming.
In the present study, we investigated which cognitive functions in older adults at Time A are predictive of conversion to dementia of the Alzheimer's type (DAT) at Time B. Forty-seven healthy individuals were initially tested in 1992-1994 on a trial-by-trial computerized Stroop task along with a battery of psychometric measures that tap general knowledge, declarative memory, visual-spatial processing, and processing speed. Twelve of these individuals subsequently developed DAT. The errors on the color incongruent trials (along with the difference between congruent and incongruent trials) and changes in the reaction time distributions were the strongest predictors of conversion to DAT, consistent with recent arguments regarding the sensitivity of these measures. Notably in the psychometric measures, there was little evidence of a difference in declarative memory between converters and nonconverters, but there was some evidence of changes in visual-spatial processing. Discussion focuses on the accumulating evidence suggesting a role of attentional control mechanisms as an early marker for the transition from healthy cognitive aging to DAT.
Department of Psychology, Washington University, St. Louis, MO 63130, USA. dbalota@artsci.wustl.edu
David A
DA
Balota
Chi-Shing
CS
Tse
Keith A
KA
Hutchison
Daniel H
DH
Spieler
Janet M
JM
Duchek
John C
JC
Morris
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis*; D001288:Attention; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D011379:Prognosis; D011594:Psychometrics / Q000706:statistics & numerical data; D011930:Reaction Time; D015203:Reproducibility of Results; D057190:Stroop Test / Q000706:statistics & numerical data*