Brief personalised rhythmic auditory stimulation facilitates cognitive and neural processing in ageing

There is growing interest in non-invasive brain stimulation (NIBS) as a
safe and practical method to support cognitive function during ageing.
NIBS using rhythmic sensory stimuli entrains brain oscillations and
synchronises functional networks, but the choice of NIBS frequency to
enhance performance in cognitive tasks remains unclear. We adopt a network
neuroscience approach to NIBS, linking network connectivity, EEG
oscillatory frequencies, and behavioural performance, to test the effects
of personalised rhythmic auditory stimulation (RAS) on an inhibitory
control task (Simon task) in older adults aged 60–75 years. Simon task
trials were preceded by ≈1.7–3.2 s of personalised RAS (clicks) at each
individual’s theta oscillation frequency (fθ), a slightly faster variant
(fθ+), a fixed low-frequency control at 2 Hz (f2Hz), or a non-rhythmic
control (NR). Reaction times (RTs) after personalised stimulation were
faster than f2Hz and NR, with stronger brain entrainment to rhythmic
stimulation linked to faster RTs. Task-related EEG signals showed enhanced
attentional processes and more efficient cortical responses following the
personalised stimulation. Individuals with lower baseline performance had
the greatest benefits. The findings suggest personalised RAS enhances
cognitive performance in ageing and provides a cost-effective
neurorehabilitation approach to mitigate age-related cognitive decline.