Cerebellar transcranial direct current stimulation for learning a novel split-belt treadmill task: a randomised...

Area of Science:

• Neuroscience
• Motor Control
• Rehabilitation

Background:

• Split-belt treadmill training is a common task for studying motor adaptation and learning.
• Cerebellar transcranial direct current stimulation (ctDCS) is a non-invasive brain stimulation technique explored for modulating motor learning.
• Understanding the effects of cerebellar stimulation on motor learning is crucial for developing effective rehabilitation strategies.

Purpose of the Study:

• To investigate the impact of repeated anodal cerebellar transcranial direct current stimulation (ctDCS) on the learning process during split-belt treadmill training.
• To assess whether anodal ctDCS enhances or alters motor performance and adaptation during and after the training task.
• To evaluate the effects of ctDCS on the retention and de-adaptation phases of motor learning.

Main Methods:

• Thirty healthy participants underwent three sessions of either active or sham anodal ctDCS during split-belt treadmill training.
• Motor performance was assessed at baseline, during adaptation, and during de-adaptation.
• Learning was quantified by analyzing strides to steady-state performance and evaluated for cumulative, consecutive, and session-specific effects using linear mixed-effects regression models.

Main Results:

• No significant difference in absolute learning was observed between the active and sham ctDCS groups during the adaptation phase (p > 0.05).
• Active anodal ctDCS significantly slowed the de-adaptation process compared to sham stimulation (p = 0.03).
• Secondary analyses indicated that anodal ctDCS reduced cumulative and consecutive-session effects on immediate adaptation (p = 0.01) and influenced immediate de-adaptation (p = 0.02).

Conclusions:

• Repeated anodal cerebellar ctDCS does not enhance motor learning during the adaptation phase of split-belt treadmill training.
• Anodal ctDCS appears to influence the maintenance of learned motor patterns, potentially by slowing de-adaptation.
• These findings suggest that cerebellar ctDCS might be beneficial for sustaining therapeutic effects in motor rehabilitation contexts.