Predicting Conversion to Dementia of the Alzheimer's Type in a HealthyControl Sample: The Power of Errors in Stroop Color Naming

摘要

In the present study, we investigated which cognitive functions in older adults at Time A are predictiveof conversion to dementia of the Alzheimer's type (DAT) at Time B. Forty-seven healthy individualswere initially tested in 1992-1994 on a trial-by-trial computerized Stroop task along with a battery ofpsychometric measures that tap general knowledge, declarative memory, visual—spatial processing, andprocessing speed. Twelve of these individuals subsequently developed DAT. The errors on the colorincongruent trials (along with the difference between congruent and incongruent trials) and changes inthe reaction time distributions were the strongest predictors of conversion to DAT, consistent with recentarguments regarding the sensitivity of these measures. Notably in the psychometric measures, there waslittle evidence of a difference in declarative memory between converters and nonconverters, but there wassome evidence of changes in visual-spatial processing. Discussion focuses on the accumulating evidencesuggesting a role of attentional control mechanisms as an early marker for the transition from healthycognitive aging to DAT.