Background: Details on the neural mechanisms for human hand motor control mainly derive from studies in healthy young individuals. During healthy aging, however, neurobiological changes lead to an impairment in fine motor skills with deficits in motor planning, execution and control. These age-related motor deficits critically impact activities of daily living, independence of the elderly as well as integration in modern society. Hence, the further understanding of changes in the motor system underlying skilled motor functions during healthy aging is of great importance. Objective: To gain insights in the age-related changes of neural coding of skilled motor functions by analyzing the spectral components in young and elderly recorded with electroencephalography (EEG) while performing dexterous hand movements. Methods: 63-channel EEG was recorded in 22 elderly (over the age of 60) and 26 young (under the age of 35) participants, performing either a complex finger sequence tapping task or a pinch grip task. In the movement interval, spectral power relative to baseline was calculated from 8 – 25 Hz in steps of 1 Hz using a short-time FFT multitaper approach. In order to quantify the distribution of spectral power, we estimated the spectral entropy which is an uncertainty measure describing the flatness of the frequency spectrum (Sleigh et al., 2004). The spectral entropy is calculated by H=-1/ln(N) pi ln(pi), with pi being the spectral amplitude of frequency bin i and N being equal to the number of frequency bins. A uniform flat signal with a broad spectral content results in a high spectral entropy (H~1), whereas a more predictable signal with a narrow power spectrum in a limited number of frequency bins yields a low spectral entropy (H~0). Results: Elderly showed a greater movement related power reduction in frequency bins from 13 – 19 Hz (unpaired t-test, FDR corr. p<0.05) in electrodes covering premotor areas compared to young participants. Moreover, the shape of the distribution of the power spectrum differed with age (Figure 1, inlay). Whereas young participants show a bimodal (distinguished alpha- and beta-peak), elderly display a more unimodal (over both frequency bands) power decrease. To quantify a disparity in distribution, we estimated the spectral entropy for each channel. Elderly show a higher entropy, thus a less uniform proportion distribution, pronounced in medial-frontal electrodes (rank-sum test, FDR corr. p<0.05) (Figure 1). Conclusion: Taken together, we found a flatter, more uniform frequency spectrum with a broader spectral content in the aged population compared to younger people during performance of skilled motor tasks. This points towards a less specific and more active cortex in the elderly during skilled motor tasks, supporting the view of an age-related overactivation leading to reduced specificity. Sleigh, J.W., Steyn-Ross, D.A., Steyn-Ross, M.L., Grant, C., Ludbrook, G., 2004. Cortical entropy changes with general anaesthesia: theory and experiment. Physiological measurement 25, 921–934.