Central Physiological Tremor Oscillators within a Hemifield Repetitive Visual Stimulation Paradigm

In order to analyze the activation pattern of the two putative central tremor oscillators that independently control the right and left hands, two hemifield repetitive visual stimulation tests were employed. The dynamical evolution of the tremor spectral characteristics of both hands was tracked using coherence joint time-frequency analysis. To get reliable spectral estimators for the tremor stochastic process, two non-parametric methods were applied: a Welch periodogram-based method and a multitaper method. In both cases, the results were the same: none significant coherence value could indicate a potential central driving activity