Prefrontal activation when suppressing an automatic balance recovery step.

Area of Science:

• Neuroscience
• Biomechanics
• Human Motor Control

Background:

• Response inhibition is typically studied in seated individuals, revealing a neural stopping network involving the Inferior Frontal Gyrus (IFG).
• It remains unclear if these same neural networks are involved in suppressing automatic balance recovery steps.

Purpose of the Study:

• To investigate if the Inferior Frontal Gyrus (IFG) shows greater activation when suppressing an automatic balance recovery step.
• To explore the neural mechanisms underlying response inhibition in a postural context.

Main Methods:

• Functional near-infrared spectroscopy (fNIRS) measured brain activity in 21 young adults during a balance recovery task.
• Participants performed a step (STEP) or suppressed a step (STOP) based on auditory cues following postural perturbations.
• Oxygenated hemoglobin changes in the prefrontal cortex were analyzed between STEP and STOP conditions.

Main Results:

• A greater bilateral prefrontal response was observed during STOP trials compared to STEP trials.
• This finding supports the involvement of executive brain networks in suppressing a balance recovery step.

Conclusions:

• Higher brain processes contribute to preventing falls by enabling behavioral flexibility in complex environments.
• This study introduces a novel method for assessing response inhibition in upright postural tasks requiring rapid stepping.