Looking for transfer in all the wrong places: How intellectual abilities can be enhanced through diverse experience among older adults

Research with cognitive training for older adults has largely shown that benefits are confined to the skills that are directly practiced with little or no generalization (or “transfer”) to other skills. However, investigations typically rely on pre-post designs in which the effects of training on non-practiced skills can only be revealed in the initial encounter with the novel task after training. The principle of mutualism suggests that growth in one cognitive skill may potentiate plasticity in related skills, such that transfer may only emerge with practice on the novel skill. We introduce a successive enrichment paradigm in which learning on a target skill (here, working memory (WM)) is examined as a function of earlier training experiences. Older adults were randomly assigned to one of four groups who trained on different combinations of tasks before training on a verbal WM task. Practice with any combination of WM tasks accelerated learning of the target task relative to a verbal decision speed control. Furthermore, those who first practiced multiple WM span tasks that were different from the target task showed larger pre- to posttest gain on the target WM task relative to those with prior exposure to only one different WM task or even the exact same WM task as the target. However, these effects only emerged with practice on the novel task. These data provide support for the mutualism principle — a conceptualization of transfer that can explain the emergence of the positive manifold of cognitive abilities, and offers promise for new pathways to promote late-life cognitive health.