Neuroplastic and motor behavioral changes after intermanual transfer training of non-dominant hand: A prospective...

Intermanual transfer of learning is an important movement basis for a keyboard and instrument playing movement. However, the issue of where neural plastic mechanism occurs in the brain after intermanual transfer training remains both controversial and unresolved.

The aim of present study is to investigate the neuroplastic mechanism associated with the interlimb transfer learning from non-dominant hand to dominant hand.

Twenty healthy right-handed adults were classified into either the control group (no-training) or the experimental group (training serial button-press motor task, SPMT), 5 days a week for two consecutive weeks. SPMT involved pressing the numbers 1, 2, 3, and 4 in a random sequence, which was presented in the monitor screen. Outcome measures included movement accuracy (MA), movement time (MT), and the fMRI data using a 3T MRI scanner. Repeated measures of analysis of variance (ANOVA) and non-parametric tests were used at p <0.05.

Motor performances in the MA and MT were significantly more improved in the experimental group than in the control group (p <0.05). Neuroimaging data revealed a distributed subcortical and cortical motor network including the SMA-thalamus (VL/VL)-basal ganglia-cerebellum loop, suggesting a differential and time-dependent neural network utilized during intermanual transfer learning.

Pre-training intermanual transfer learning involved a form of declarative (or explicit) motor learning, which was primarily mediated by the cortical motor network, whereas post-training involved a form of procedural knowledge, which activated subcortical and cortical motor network regions, including the SMA-thalamus (VL/VL)-basal ganglia-cerebellum loop.