The Extended Mind in Young Children: Cost-Dependent Trade-Off Between External and Internal Memory
研究5-8岁儿童在购物游戏中，根据访问外部列表的延迟成本，如何权衡使用外部资源与内部工作记忆，发现成本越高，儿童越少依赖外部列表，更多依赖记忆，且正确率更高。
Most work on working memory development has children remember a set of items as well as they can. However, this approach sidesteps the extended mind , the integration of external information with memory. Indeed, adults prefer to use external resources (e.g., lists, models) but will remember more as the cost to access them increases. Here, in our shopping game, we investigated this trade-off in 5- to 8-year-olds. Using a touchscreen, children shopped in a virtual store. Their shopping list and the store were not visible simultaneously but could be toggled. We manipulated access cost by varying a delay (0–4 s) before the list’s reappearance. Across three preregistered experiments at two sites (the United States and China, N = 141), a pattern emerged: When it was costlier to do so, children revisited the list less often, studied it longer, and selected more correct items. Also, children recognized the costs, identifying the no-delay condition as easier. Young children showed a cost-dependent trade-off of external-resource use versus working memory.