Divided attention and the encoding effects of retrieval.

Retrieving from memory both reveals as well as modifies memory. It is important to understand how these encoding effects of retrieval differ from other forms of encoding. One possible difference relates to attention: divided attention is well known to disrupt memory encoding but typically has much less impact on memory retrieval. However, less is known about the relative attentional demands of the encoding consequences of retrieval. The current experiments examined retrieval-based encoding using free recall, a retrieval task purported to require substantial attentional resources. In three experiments, participants studied common category exemplars (Phase 1), restudied or freely recalled the exemplars (Phase 2), and then took a final free-recall test (Phase 3). Phase 2 occurred under full attention (FA) or divided attention (DA). In all three experiments, the negative effect of DA on final recall was significant in the restudy but not retrieval condition. The pattern persisted with short (Experiment 1) or long study lists (Experiment 2), requiring lesser or greater retrieval effort, and with multiple Phase 2 tests, permitting the development of more elaborate retrieval strategies (Experiment 3). The encoding effects of retrieval appear resilient to distraction, even using a memory task that is more effortful and easily disrupted by DA (i.e., free recall). In addition, these results are inconsistent with elaboration and effort accounts of retrieval-based learning.