Monitoring the ebb and flow of attention: Does controlling the onset of stimuli during encoding enhance memory?

Central to the operation of the Atkinson and Shiffrin's (Psychology of learning and motivation, 2, 89-195, 1968) model of human memory are a variety of control processes that manage information flow. Research on metacognition reveals that provision of control in laboratory learning tasks is generally beneficial to memory. In this paper, we investigate the novel domain of attentional fluctuations during study. If learners are able to monitor attention, then control over the onset of stimuli should also improve performance. Across four experiments, we found no evidence that control over the onset of stimuli enhances learning. This result stands in notable contrast to the fact that control over stimulus offset does enhance memory (Experiment 1; Tullis & Benjamin, Journal of memory and language, 64 (2), 109-118, 2011). This null finding was replicated across laboratory and online samples of subjects, and with both words and faces as study material. Taken together, the evidence suggests that people either cannot monitor fluctuations in attention effectively or cannot precisely time their study to those fluctuations.