Strategy shift affordance and strategy choice in young and older adults.

When skill acquisition involves a shift in strategy (such as from rule-based to retrieval-based processing), older adults typically shift later in practice than young adults do. We observed the shift from scanning-based to memory-based processing in a noun pair learning task. Young and older adults were trained in conditions in which the relationship between memory load and scanning load was manipulated by making the strategy shift more or less beneficial. Older adults in a condition with high shift affordance shifted to memory retrieval more fully and more rapidly than did older adults in conditions with lower shift affordance. Reluctance to rely on memory retrieval was related to metacognitive reports of memory confidence. The present study indicates that age differences in skill acquisition reflect qualitative age differences in strategy choice in addition to quantitative age differences in component task processes.