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Movement-related potentials in Parkinson's disease. Presence and predictability of temporal and spatial cues.
A proposed model of the interaction between the basal ganglia and the supplementary motor area is proposed, involving the temporal organization of voluntary and internally determined sequential movements.
Bimanual co-ordination in Parkinson's disease.
For Parkinson's disease patients, performance of the in- phase movement was more accurate and stable when an external timing cue was used; however, for anti-phase movement, the external cue accentuated the tendency for patients to revert to more symmetrical, in-phase movements.
Impairments of movement initiation and execution in unilateral neglect. Directional hypokinesia and bradykinesia.
It is suggested that directional hypokinesia is associated with both left hemisphere and right hemisphere damage, but only in the context of unilateral neglect, and the site of hemispheric lesion may determine the temporal characteristics of movement impairments in neglect.
Horizontal visual motion modulates focal attention in left unilateral spatial neglect.
The extent to which patients were susceptible to the effects of background motion was not related to severity of unilateral spatial neglect, as measured by clinical tests, and the benefits of leftward motion may reflect activity of preserved motion processing mechanisms, which provide input to an otherwise dysfunctional attentional network.
An evaluation of the role of internal cues in the pathogenesis of parkinsonian hypokinesia.
It is concluded that for well-learnt, predictable sequences the basal ganglia provide a non-specific internal cue that is necessary for switching between one movement and the next in a movement sequence, and also for development of preparatory activity for each sub-movement in the sequence.
Residual rightward attentional bias after apparent recovery from right hemisphere damage: implications for a multicomponent model of neglect.
It is suggested that restitution of the capacity to reorient attention contralesionally may underlie the apparent recovery from clinical signs of unilateral neglect, and may account for the poor functional outcomes in some apparently "recovered" patients.
Age-related motor slowness: simply strategic?
The results suggest a decline in motor coordination rather than any simple strategic preference for caution in movement and the hesitancy of movement to some extent parallels that seen in Parkinson's disease.
The right shift theory of a genetic balanced polymorphism for cerebral dominance and cognitive processing. Commentaries. Author's reply
The right shift (RS) theory of handedness (Annett, 1972, 1985) suggested that the high prevalence of human right-handedness and left hemisphere specialization for speech is due to a single factor
Movement-related potentials in Parkinson's disease. Motor imagery and movement preparation.
Early-stage pre-movement activity was present in both Parkinson's disease patients and control subjects when they imagined movement, but was reduced in amplitude compared with that for actual movement, indicating impaired termination following the motor response.