electrodes , beta oscillations and PD
 

http://news.bbc.co.uk/2/hi/science/nature/8287047.stm

Making people move in slow motion
By Victoria Gill
Science reporter, BBC News



Brain waves appear to have a direct effect on behaviour
Researchers have used electrodes to make people move in slow motion.

The scientists "boosted" human subjects' brain waves - applying a small alternating current via electrodes on the volunteers' scalps.

These waves are patterns generated naturally by groups of neurons, or brain cells, firing in a rhythm. ..


"Different parts of the brain work together and generate certain frequencies," he explained, "and the movement areas of the brain come together in beta activity.

"That activity is suppressed just prior to and during movement, so we think the body gets rid of it to prepare to make a new movement." ..



"When we applied the beta stimulation ... quick movement was slowed by 10%.


"So this information is very helpful," he said. "Since we've shown that this slows people down, it tells us what Parkinson's disease treatments should be trying to suppress."

Professor John Stein, a neuroscientist from the University of Oxford pioneered the theory of what he refers to as a "beta straitjacket" - a pattern of brain activity that prevents Parkinson's disease patients from making voluntary movements.

"The theory is that... in Parkinson's disease when people try to move they cannot suppress beta [brain waves] and therefore cannot move," he told BBC News.

"This study is the first to show... in normal subjects that beta activity actually slows movement. This supports a causal role for [the] activity in causing a fixed posture and tending to prevent voluntary movements."

oscillations in basal ganglia
 

http://www.springerlink.com/content/m3784n85ut8m7716/

Journal of Neural Transmission. Supplementa
Parkinson’s Disease and Related Disorders

P. Riederer, H. Reichmann, M. B. H. Youdim and M. Gerlach

Bad oscillations in Parkinson’s disease
P. Brown4

(4) Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, Queen Square, London, WC1N 3BG, UK

Summary
Recordings in humans...have revealed a tendency for basal ganglia neurons to oscillate and synchronise their activity, giving rise to a rhythmic population activity, manifest as oscillatory local field potentials. The most important activity is synchronised oscillation in the beta band (13–30 Hz), which has been picked up at various sites within the basal ganglia-cortical loop in PD. Dopaminergic medication and movement suppress this activity, with the timing and degree of suppression closely correlating with behavioural performance...


(more info about beta oscillations in movement disorders:)

http://brain.oxfordjournals.org/cgi/...full/127/4/721