Alpha oscillatory correlates of motor inhibition in the aged brain

TL;DR

This study explores how aging affects the brain's ability to inhibit movements, finding that older adults show reduced alpha brain activity during inhibition, but both young and elderly benefit from overnight consolidation.

Contribution

The study reveals age-related differences in alpha oscillatory correlates of motor inhibition and the role of consolidation in enhancing inhibitory control.

Findings

Young participants showed increased alpha power during motor inhibition, while elderly did not.

Both age groups showed improved alpha power up-regulation after an overnight consolidation phase.

The findings suggest age-related deficits in local inhibitory mechanisms but also neuroplastic improvements over time.

Abstract

Exerting inhibitory control is a cognitive ability mediated by functions known to decline with age. The goal of this study is to add to the mechanistic understanding of cortical inhibition during motor control in aged brains. Based on behavioral findings of impaired inhibitory control with age we hypothesized that elderly will show a reduced or a lack of EEG alpha-power increase during tasks that require motor inhibition. Since inhibitory control over movements has been shown to rely on prior motor memory formation, we investigated cortical inhibitory processes at two points in time—early after learning and after an overnight consolidation phase and hypothesized an overnight increase of inhibitory capacities. Young and elderly participants acquired a complex finger movement sequence and in each experimental session brain activity during execution and inhibition of the sequence was recorded with multi-channel EEG. We assessed cortical processes of sustained inhibition by means of task-induced changes of alpha oscillatory power. During inhibition of the learned movement, young participants showed a significant alpha power increase at the sensorimotor cortices whereas elderly did not. Interestingly, for both groups, the overnight consolidation phase improved up-regulation of alpha power during sustained inhibition. This points to deficits in the generation and enhancement of local inhibitory mechanisms at the sensorimotor cortices in aged brains. However, the alpha power increase in both groups implies neuroplastic changes that strengthen the network of alpha power generation over time in young as well as elderly brains.

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