The relationship between oscillatory activity and motor reaction time in the parkinsonian subthalamic nucleus.
Averaging techniques have demonstrated that movement preparatory cues and movement itself are associated with marked reductions in the oscillatory synchrony of local neuronal populations in the area of the human parkinsonian subthalamic nucleus (STN), as indexed by 8-30 Hz local field potential (LFP) activity. In order to examine the detailed nature and strength of the relationship between reductions in oscillatory activity and movement we examined single-trial LFP activity recorded from the STN area of parkinsonian subjects engaged in a choice reaction task. In this task an initial warning cue was either fully predictive or non-predictive of the hand required to make a later motor response. This motor response was elicited by a second go cue to which data were aligned. We observed a significant linear relationship between the onset time of oscillation reduction after go cues and subsequent motor response time across single trials within subjects. Consistent with this observation we also found a positive correlation of power with response time following go cues. In addition, we observed shorter durations of suppression in fully predictive trials where selection of the response could precede go cue presentation. The results are consistent with the hypothesis that reductions in 8-30 Hz population synchrony in the STN area are related to the processing required for motor preparation, particularly response selection.
Williams
David
D
Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, Queen Square, London WC1N 3BG, UK.
Kühn
Andrea
A
Kupsch
Andreas
A
Tijssen
Marina
M
van Bruggen
Gerard
G
Speelman
Hans
H
Hotton
Gary
G
Loukas
Constantinos
C
Brown
Peter
P
D000368:Aged; D001683:Biological Clocks; D001931:Brain Mapping; D002755:Choice Behavior / Q000502:physiology*; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D020734:Parkinsonian Disorders / Q000503:physiopathology*; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology*; D013057:Spectrum Analysis; D020531:Subthalamic Nucleus / Q000503:physiopathology*