Data from: Perturbation-evoked cortical responses associated with balance ability

Background: Reactive balance recovery evokes a negative peak of cortical
electroencephalography (EEG) activity (N1) that is simultaneous to
brainstem-mediated automatic balance-correcting muscle activity. This
study follows up on an observation from a previous study, in which N1
responses were larger in individuals who seemed to have greater difficulty
responding to support-surface perturbations. Research Question: We
hypothesized that people engage more cortical activity when balance
recovery is more challenging. We predicted that people with lower balance
ability would exhibit larger cortical N1 responses during balance
perturbations. Methods: In 20 healthy young adults (11 female, ages 19-38)
we measured the amplitude of the cortical N1 response evoked by 48
backward translational support-surface perturbations of unpredictable
timing and amplitude. Perturbations included a Small (8 cm) perturbation
that was identical across participants, as well as Medium (13-15 cm) and
Large (18-22 cm) perturbations scaled to participant height to control for
height-related differences in perturbation difficulty. To assess
individual differences in balance ability, we measured the distance
traversed on a narrow (0.5-inch wide) 12-foot beam across 6 trials. We
tested whether the cortical N1 response amplitude was correlated to
balance ability across participants. Results: Cortical N1 amplitudes in
response to standing balance perturbations (54±18 μV) were inversely
correlated to the distance traveled in the difficult beam-walking task
(R2=0.20, p=0.029). Further, there was a significant interaction between
performance on the beam-walking task and the effect of perturbation
magnitude on the cortical N1 response amplitude, whereby individuals who
performed worse on the beam-walking task had greater increases in N1
amplitudes with increases in perturbation magnitude. Significance:
Cortical N1 response amplitudes may reflect greater cortical involvement
in balance recovery when challenged. This increased cortical involvement
may reflect cognitive processes such as greater perceived threat or
attention to balance, which have the potential to influence subsequent
motor control.   Note: This data set has also been
appended to include additional data from the same data collection in the
same participant cohort associated with the manuscript "Cortical beta
oscillatory activity evoked during reactive balance recovery scales with
perturbation difficulty and individual balance ability" submitted to
NeuroImage