Boosting Proactive Motor Control via Statistical Learning with Brain Stimulation
Description
Visual statistical regularities are nested patterns of information extracted to build a predictive internal model that guides attentional and motor decisions. Here, we sought to understand the contributions of the left and right frontoparietal areas in modulating the effect of this expectancy implementation on premotor preparation. Healthy subjects were asked to detect a high-contrast stimulus target presented simultaneously with a distractor, with preceding color cues indicating, trial by trial, the pairing between the response hand and the upcoming stimuli locations. Performance was measured at baseline, and immediately after a one-session training on the task. During the training target locations appeared 75% of the time to the right of the distractor, a regularity unnoticed by participants. The training session was paired with unilateral transcranial random noise stimulation (tRNS) or sham stimulation over the left or right frontoparietal cortex in a counterbalanced design. Results showed a significant response bias in reaction times after training, with faster responses for targets to the right of the distractor. This bias was enhanced by right, but not left, frontoparietal stimulation, highlighting a hemispheric asymmetry in proactive motor control. The implicit nature of learning, as evidenced by subjects’ unawareness of probability distributions, underscores how proactive motor control quickly adapts to statistical regularities. Results suggest a dominant role for the right hemisphere in mediating attentional learning effects, with implications for understanding lateralized functions in adaptation of the motor control. data.accuracy 0=incorrect response 1=correct response data.conditions stimulus position in the circle LC left central DL down left DC down central DR down right RC right central UR up right UC up central UL up left HV Horizontal target on the first stimulus VH Horizontal target on the second stimulus VV Both stimuli are vertical RIGHT_ON1 the cue that matches the right is on the first stimulus RIGHT_ON2 the cue that matches the right is on the second stimulus typeoftraining 1=Unbalanced 2=Balanced LEFT MONTAGE: Subjects L1-L24 RIGHT MONTAGE: Subjects R1-R24 Every subject's folder contains a subfolder for the ACTIVE session and a folder for the SHAM session. within each of those subfolder a file with filename containg: -"PRE" indicates data collected during the baseline task, -"TRAINING" indicates data collected during the training task, -"POST" indicates data collected during the post training task.