Neuroelectric indices of motor response preparation are selectively associated with physical activity among adults with obesity.

Previous work has demonstrated that physical activity and weight status are associated with attentional inhibition (indexed with the P3 component of event-related potentials). However, there is limited knowledge on the neural underpinnings of motor response planning and activation. This study investigated the effect of weight status on relationships between moderate-to-vigorous physical activity (MVPA) and the lateralized readiness potential (LRP), a neuroelectric index of motor response planning and activation. Adults (N = 165 [98 females]) wore ActiGraph wGT3X+ accelerometers to measure physical activity. Behavioral outcomes were recorded during the modified Eriksen Flanker task to assess attentional inhibition. EEG recordings were taken to elucidate response- (LRP-R) and stimulus-locked (LRP-S) LRPs, and P3. Participants were separated into groups based on the BMI cutoff of 30 kg/m (i.e., non-obese [n = 88], obese [n = 77]). Independent t-tests and ANCOVA were conducted to determine differences between groups. Regression analyses within each group were conducted to determine relationships between MVPA and LRP and P3 amplitude and latencies. There was no difference in MVPA between weight groups after adjustment for age and sex, although the non-obese group had significantly higher incongruent accuracy (p = 0.007). Only in the obese group, MVPA was positively associated with LRP-R incongruent (β = 0.014, p = 0.029) and LRP-S congruent (β = 0.013, p = 0.008) amplitude, and inversely associated with LRP-S incongruent (β = -0.488, p = 0.017) and P3 congruent (β = 0.013, p = 0.008) fractional area latency. MVPA was associated with pre-motor planning and activation only among persons with obesity. Future work should study the impact of physical activity on neuroelectric indices of motor responses in people with obesity.