The effect of aging on EEG brain oscillations related to sensory and sensorimotor functions

PurposeThe question of the present study is whether the brain as a system with gradually decreasing resources maximizes its performance by reorganizing neural networks for greater efficiency.Material/methodsAuditory event-related low frequency oscillations (delta δ – [2, 4] Hz; theta θ – [4.5, 7] Hz; alpha α – [7.5, 12] Hz) were examined during an auditory discrimination motor task (low-frequency tone – right hand movement, high-frequency tone – left hand movement) between two groups with mean age 26.3 and 55 years.ResultsThe amplitudes of the phase-locked δ, θ and α activity were more pronounced with a progressive increase in age during the sensory processing, independent of tone type. The difference between the groups with respect to scalp distribution was tone-independent for delta/theta oscillations, but not for the alpha activity. Age-related and tone-dependent changes in α band activity were focused at frontal and sensorimotor areas. Neither functional brain specificity was observed for the amplitudes of the low-frequency (δ, θ, α) oscillations during the cognitive processing, which diminished with increasing age.ConclusionThe cognitive brain oscillatory specificity diminished with increasing age.