Finger tremor can be voluntarily reduced during a tracking task

A dominant role for mechanical resonance in physiological finger tremor revealed by selective minimization of voluntary drive and movement

“…Most studies show an altered frequency spectrum when inertia is added to the finger or during slow movements of the finger. It seems to be a general finding that, under postural conditions, tremor tends to be dominated by high frequencies (Daneault et al 2011), whereas, when increased level of activation is required, as in loading (Stiles and Randall 1967) or tracking conditions (Vallbo and Wessberg 1993;Vallbo 1995, 1996), the high-frequency peak drops to a lower frequency or the low frequency greatly predominates. Our results (see Fig.…”

“…With increasing amounts of activation, it dropped to ϳ10 Hz, and the overall amplitude of acceleration increased. In general, postural finger tremor is described as acceleration with two main components in its spectrum: one between 8 and 12 Hz, and one between 15 and 30 Hz (e.g., Daneault et al 2011;Elble 1996;Lakie et al 1992;Raethjen et al 2000;Stiles and Randall 1967). Most studies show an altered frequency spectrum when inertia is added to the finger or during slow movements of the finger.…”

“…This physiological finger tremor is generally described as semiregular oscillations of the limb with distinct acceleration peaks at one or two frequencies, around 8 -12 Hz and/or over 15 Hz (e.g., Daneault et al 2011;Elble 1996;Raethjen et al 2000;Stiles and Randall 1967). There is a long-standing debate on the origin of physiological finger tremor.…”

The organization of upper limb physiological tremor

“…The major difference between the position feedback condition and the tremor modulation condition is that in the former, only the position of the finger was presented while in the latter, the position was presented in concert with the amplitude of tremor. Note that the visual feedback was presented with a minute delay of 70 ms introduced by the filtering method (Daneault et al 2011). However, since this delay is so small, it was inconsequential for the participants.…”

“…However, in that study, only a feedback of finger position was given to the participants, not the actual tremor. In recent papers (Carignan et al 2009;Daneault et al 2010Daneault et al , 2011, we demonstrated that physiological tremor amplitude of the finger can be voluntarily reduced. In those studies, finger tremor and not position was given as feedback to the participants.…”