Abstract
Visuomotor adaptation is essential to learning to recalibrate movements when environmental conditions change. Previous work showed that learning to counteract an abrupt perturbation under a single- or dual-task setting (i.e., attentional context) was re-learned better under the same attentional context. This suggested that the attentional context was encoded during learning and used as a recall cue. Using fMRI, this study investigated the neural mechanisms mediating the effects of attentional contexts on visuomotor adaptation. Participants moved a cursor to a target while learning to counteract a 45° cursor rotation, with or without performing a secondary (e.g., RSVP) task. Each participant experienced three different conditions, which varied in whether they performed a secondary task during the learning and re-learning phases. In the single-single and dual-dual conditions, they performed the visuomotor rotation task under consistent attentional contexts. In contrast, in the dual-single condition, they performed the visuomotor rotation task under inconsistent attentional contexts. fMRI analyses revealed that in the consistent but not inconsistent conditions, the brain regions in the default mode network (DMN), including the posterior cingulate cortex, precuneus, and angular gyrus, increased activity during re-learning than initial learning. However, the inconsistent condition showed greater activations in frontal, parietal and occipital cortices and cerebellum (VI) during re-learning. Functional connectivity analyses suggested that correlations between activations of the putamen in the dorsal striatum and the precuneus in the DMN were positively associated with behavioural performance during re-learning in the consistent (single-single and dual-dual) conditions. Our results suggest that enhanced re-learning under an attentional context consistent with the initial learning is associated with decreased frontal-parietal-occipital and cerebellar activations but increased DMN activation, reflecting that the task has become less effortful. Functional connections between the striatum and the DMN appear to be linked to enhanced performance when attentional contexts match between learning and re-learning.