The current study of older adults used structural equation modeling (SEM) to examine the relationships between three executive processes underlying executive function (EF) (inhibition, task-switching, and updating in working memory), and two types of instrumental activities of daily living (IADLs) (self-report and performance-based). Experimental tasks of executive attention from the cognitive psychology literature and self-report or performance-based IADL tests from the medical literature were measured to create the latent constructs of interest (EF and IADL). Confirmatory factor analysis (CFA) was used to examine the construct validity of EF and IADL. Nested two-factor models of EF were compared to a three-factor model of EF. A nested, one-factor model of IADL was compared to a two-factor model of self-report and performance-based items. A three-factor model of inhibition, updating, and task-switching was endorsed in favor of a two-factor model of EF. A two-factor model of self-report and performance-based provided the best fit to the data in the model of IADL. As predicted, when the latent variable relationships were analyzed, executive processes had a significant relationship with performance-based, but not self-report IADLs. In addition, and as predicted from the greater age differences seen on experimental measures of updating and task-switching, updating had a strong and significant relationship with performance-based IADL (.40), followed by task-switching (.22), and inhibition (.10). The results of this study uniquely show a direct relationship between executive processes and IADLs, thus demonstrating that experimental measures of EF have ecological utility. Further, these results point to areas of cognitive rehabilitation that may strategically impact older adults' performance on daily life activities.
|Commitee:||Baranek, Grace, Gordon, Peter, Mulligan, Neil, Panter, Abigail|
|School:||The University of North Carolina at Chapel Hill|
|School Location:||United States -- North Carolina|
|Source:||DAI-B 69/04, Dissertation Abstracts International|
|Keywords:||Aging, Executive function, Executive processes, Instrumental activities of daily living|
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