Latent change models of adult cognition: are changes in processing speed and working memory associated with changes in episodic memory?
The authors used 6-year longitudinal data from the Victoria Longitudinal Study (VLS) to investigate individual differences in amount of episodic memory change. Latent change models revealed reliable individual differences in cognitive change. Changes in episodic memory were significantly correlated with changes in other cognitive variables, including speed and working memory. A structural equation model for the latent change scores showed that changes in speed and working memory predicted changes in episodic memory, as expected by processing resource theory. However, these effects were best modeled as being mediated by changes in induction and fact retrieval. Dissociations were detected between cross-sectional ability correlations and longitudinal changes. Shuffling the tasks used to define the Working Memory latent variable altered patterns of change correlations.
Hertzog
Christopher
C
School of Psychology, Georgia Institute of Technology, 654 Cherry Street, Atlanta, Georgia 30332-0170, USA. christopher.hertzog@psych.gatech.edu
Dixon
Roger A
RA
Hultsch
David F
DF
MacDonald
Stuart W S
SW
D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008569:Memory Disorders / Q000523:psychology*; D008606:Mental Processes; D008875:Middle Aged; D008960:Models, Psychological