title: Alpha and beta changes in cortical oscillatory activity in a go/no go randomly-delayed-response choice reaction time paradigm.
abstract: OBJECTIVE
  Predictable movements induce oscillatory changes over the contralateral motor cortex that begin before the movement, but their significance has not been fully established. We studied non-phase-locked changes in cortical oscillatory activity in a S1-centred double-stimulus go/no go paradigm with random interstimulus interval.
  
  
  METHODS
  About 58 reference-free EEG channels were analyzed by means of Gabor transforms in a group of 10 healthy subjects. A 2000 Hz tone (S1go, 84% probability) indicated the subject to make a brisk wrist extension after a second 2000 Hz tone (S2go). The S1-S2 interval was either 1.5, 3 or 4.5 s. A 1000 Hz tone (S1 no go, 16% probability) indicated the subject not to move (and wait for another S1 tone).
  
  
  RESULTS
  A frontal 15 Hz synchronization was observed after S1 in all conditions. No further significant changes were observed in the no go condition. A small pre-S2 alpha and beta desynchronization could be observed only in the 3 and 4.5s-interval go conditions, being larger in the latter.
  
  
  CONCLUSIONS
  These results suggest that the predictability of the timing of a movement influences the appearance of the pre-movement oscillatory changes; not only motor planning (the 'go' decision) is necessary, but also an estimation of when to move.
  
  
  CONCLUSIONS
  Our findings provide new insight on the relationship between the decision-making process, movement, and cortical oscillatory activity.
authors.affiliation: Neurophysiology Laboratory, Neuroscience Area, Centre for Applied Medical Research, Universidad de Navarra, Pamplona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Alegre
authors.forename: L
authors.initials: L
authors.lastname: Imirizaldu
authors.forename: M
authors.initials: M
authors.lastname: Valencia
authors.forename: J
authors.initials: J
authors.lastname: Iriarte
authors.forename: J
authors.initials: J
authors.lastname: Arcocha
authors.forename: J
authors.initials: J
authors.lastname: Artieda
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001931:Brain Mapping; D002755:Choice Behavior / Q000502:physiology*; D004569:Electroencephalography / Q000145:classification*; D004576:Electromyography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D009483:Neuropsychological Tests; D011930:Reaction Time / Q000502:physiology*; D013997:Time Factors