Assessing Flexibility of Solution Strategy: Strategy Shifting as a Measure of Cognitive Reserve

ObjectivesThis series of experiments explores whether flexibility in strategy shifting might function as an expression of cognitive reserve (CR).MethodsA reasoning task was designed using matrix reasoning stimuli that each required 1 of 2 specific solution strategies: logicoanalytic and visuospatial. It was formatted as a task-switching paradigm, assessing the ability to switch between solution strategies as measured by switch costs. Study 1 was done on Amazon Mechanical Turk and included an assessment of CR proxies. Study 2 used participants who had been studied extensively with neuropsychological assessments and structural neuroimaging.ResultsStudy 1 found that switch costs increased with aging. In addition, a relationship between switch costs and CR proxies was noted, suggesting a relationship between the flexibility of strategy shifting and CR. The results of Study 2 again indicated that age negatively affected strategy-shifting flexibility, but that individuals with higher CR as measured with standard proxies performed better. The flexibility measure accounted for additional variance in cognitive performance over that explained by cortical thickness, suggesting that it may contribute to CR.DiscussionOverall, the results are consistent with the idea that flexibility in strategy shifting might be 1 cognitive process that underlies cognitive reserve.