Examining Neural Plasticity for Slip-Perturbation Training: An fMRI Study

Area of Science:

• Neuroscience
• Motor Control
• Cognitive Neuroscience

Background:

• Perturbation-based balance training enhances reactive balance responses, reducing fall risk in older adults.
• Neural substrates for reactive balance control plasticity during challenging tasks remain largely unknown.
• Understanding training-induced brain changes is crucial for developing effective balance interventions.

Purpose of the Study:

• To investigate neural substrates involved in adaptation to slip-like perturbations during walking.
• To examine brain plasticity using functional neuroimaging and mental imagery after perturbation training.
• To determine if specific cortical and subcortical areas change activity with balance training.

Main Methods:

• Ten healthy young adults underwent 3 days of treadmill-slip perturbation training with increasing slip magnitudes.
• Functional magnetic resonance imaging (fMRI) recorded brain activity during imagined slipping and walking tasks before and after training.
• Behavioral measures included the number of compensatory steps and center of mass stability.

Main Results:

• Participants showed reduced compensatory steps and increased stability on day 3 compared to day 1 at higher perturbation intensities.
• Before training, imagined slipping activated the supplementary motor area (SMA), parietal, parahippocampal, and cingulate gyri.
• After training, imagined slipping showed increased activation in the dorsolateral prefrontal cortex (DLPFC), superior parietal lobule, inferior occipital gyrus, and lingual gyrus.

Conclusions:

• Perturbation training induces learning-related changes in cortical structures for adapting to walking perturbations.
• Effective balance responses to perturbations require higher-level processing for movement timing and sequencing.
• The central nervous system (CNS) recruits the DLPFC, motor, parietal, and occipital cortices for adapting to balance-threatening postural tasks.