Establishing a Neural Marker for Inhibitory Control During Balance Recovery

Considerable evidence attests to a relationship between executive function and falls. Notable among cognitive elements related to fall risk is the ability to suppress a highly automatic but unwanted action-that is, response inhibition. Although the ability to stop may seem like an unlikely foundation for maintaining balance, there are many situations in daily life where the ability to adapt planned action is critical to reducing instability. Most of what we know about the role of inhibition in balance control is based on correlations between cognitive test performance and self-reported falls, leaving a sizable gap in understanding mechanisms linking inhibition and balance control. Here, we expand from traditional balance assessments that accentuate reflexive action and instead impose a need to suppress a prepotent balance recovery step. We leveraged techniques developed in cognitive neuroscience to expose neuromuscular events leading to successful inhibition. Specifically, we used high-density electroencephalography to measure neural markers previously shown to predict successful inhibition in seated voluntary reaction tasks using hand responses (ß-bursts) and applied this to a balance recovery step task. Contrary to our hypothesis, higher ß-burst volume after a stop cue was associated with failed step suppression. Other ß oscillation characteristics revealed slightly earlier ß-burst onsets in successful suppression trials and higher average ß power prior to the stop signal for successful versus failed stop trials. The current study offers insight into potential key markers underlying suppression of a recovery step, and we highlight unique challenges associated with studying cognitive processes during rapid, whole-body balance recovery.