Intraindividual variability may not always indicate vulnerability in elders' cognitive performance.
This study examined consistency of performance, or intraindividual variability, in older adults' performance on 3 measures of cognitive functioning: inductive reasoning, memory, and perceptual speed. Theoretical speculation has suggested that such intraindividual variability may signal underlying vulnerability or neurologic compromise. Thirty-six participants aged 60 and older completed self-administered cognitive assessments twice a day for 60 consecutive days. Intraindividual variability was not strongly correlated among the 3 cognitive measures, but, over the course of the study, intraindividual variability was strongly intercorrelated within a task. Higher average performance on a measure was associated with greater performance variability, and follow-up analyses revealed that a higher level of intraindividual variability is positively associated with the magnitude of a person's practice-related gain on a particular measure. The authors argue that both adaptive (practice-related) and maladaptive (inconsistency-related) intraindividual variability may exist within the same individuals over time.
Allaire
Jason C
JC
Department of Psychology, North Carolina State University, Raleigh, NC 27695-7801, USA. jason_allaire@ncsu.edu
Marsiske
Michael
M
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000453:epidemiology; D000704:Analysis of Variance; D005260:Female; D006801:Humans; D007206:Individuality; D008297:Male; D008568:Memory; D008875:Middle Aged; D015999:Multivariate Analysis; D009483:Neuropsychological Tests / Q000706:statistics & numerical data*; D011214:Practice, Psychological; D011340:Problem Solving; D011594:Psychometrics / Q000706:statistics & numerical data; D011930:Reaction Time; D012044:Regression Analysis; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000706:statistics & numerical data; D013223:Statistics as Topic