Abstract
We recently demonstrated that the success of motor memory retrieval depends on whether participants consistently performed a secondary task during visuomotor adaptation and later recall, which was independent of available attentional resources (Song and Bédard, 2015). To date, the reinstatement of attentional context in visuomotor memory retrieval has been established only when a large visuomotor rotation (e.g., 45º) is introduced abruptly, which presumably triggers explicit awareness of the sensorimotor disturbance. Two remaining questions are 1) whether a gradually induced external perturbation also facilitates attentional context-dependent memory formation and, if so, 2) whether there is a critical temporal window for encoding the attentional state into visuomotor memory. To address these questions, we employed a gradual visuomotor rotation (from 0º to 45º) of cursor movement relative to hand movement on each trial during adaptation. In Experiment 1, we combined the gradual visuomotor adaptation task with an attention-demanding secondary task. We observed that visuomotor adaptation acquired under attentional distraction was relearned better under attentional distraction at recall. This result provides support that the formation of attentional context-dependent memory can occur even when the sensorimotor perturbation is gradually introduced. In Experiment 2, we examined whether the magnitude of motor errors determines the critical window for integration between attentional context and visuomotor memory since motor errors increased throughout the adaptation stage. We manipulated whether participants performed the secondary task concurrently in the early or late phase of visuomotor adaptation and whether they performed the secondary task at recall to match the attentional state to the early or late learning phase. We observed no difference in recall performance across early versus late learning phase groups. Further investigation will clarify whether this result is attributable to a flexible time window for attentional state encoding or a failure to integrate attentional context during visuomotor memory formation.