Effect of self-reported internal memory strategy use on age-related episodic and working memory decline: Contribution of control processes.

Abstract
We explored whether control processes could account for age-related differences in internal strategy use, which in turn would contribute to episodic and working memory decline in aging. Young and older adults completed the internal strategy subscale of the Metamemory in Adulthood (MIA) questionnaire, a free-recall task (FRT), a reading span task (RST), and 3 executive control tasks (the Wisconsin Card Sorting Test, the Initial Letter Fluency Test, and the Digit Symbol Substitution Test) allowing us to calculate a composite index of control processes. Results indicated that both self-reported internal strategy use and control processes index accounted for a significant proportion of the age-related variance in the FRT and the RST. However, once the control processes index was controlled for, variance in both the FRT and RST explained by internal strategy use were significantly reduced. Additionally, age-related variance in internal strategy use was mediated by the control processes index. These results suggest a cascade model in which individual control level would mediate age-related differences in internal strategy use, which in turn would mediate age-related differences in episodic and working memory performance. Public Significance Statement Control processes play a crucial role in episodic and working memory functioning. These processes could be considered as a cognitive resource sustaining internal strategy implementation. Deficits in control processes in older adults would be responsible for the age-related decline in internal strategy use, thereby contributing to episodic and working memory decline in aging.