1. A postural hand tremor of enhanced size was induced in eleven subjects. There was rhythmic activity in the posturally active extensor muscles synchronised to the tremor oscillation, which implied an oscillatory modulation of motor neurones. 2. The subjects executed single rapid wrist flexion movements in response to a flash of light. The light flash was… (More)
Powerful photic stimulation was employed to produce driving of the EEG rhythm recorded from occipital cortex. The resulting quasi-sinusoidal signal was considerably larger than the spontaneous alpha rhythm, and Fourier analysis showed it to be sharply tuned to the frequency of the stimulation which ranged from 7-11 Hz. Physiological postural hand tremor was… (More)
OBJECTIVES To determine whether factors associated with postural tremor operate by altering muscle interstitial K(+). METHODS An experimental approach was used to investigate the effects of procedures designed to increase or decrease interstitial K(+). Postural physiological tremor was measured by conventional means. Brief periods of ischaemic muscle… (More)
The thresholds for detection of a tremor-like movement are described. Detection is poorest at frequencies which correspond to natural tremor. The results are in accord with the failure of persons often to notice that their hands are tremulous.
Involuntary muscle activations are diagnostic indicators of neurodegenerative pathologies. Currently detected by invasive intramuscular electromyography, these muscle twitches are found to be visible in ultrasound images. We present an automated computational approach for the detection of muscle twitches, and apply this to two muscles in healthy and motor… (More)