article i nfo Article history: Accepted 22 September 2012 Available online 29 September 2012 Inhibitory control of actions is one important aspect in daily life to warrant adequate context related behavior. Alphaactivity(oscillatorybrainactivityaround10 Hz)hasbeensuggestedtoplayamajorrolefortheimplemen- tation of inhibitory control. In the present study electrophysiological correlates of voluntary suppression of acquired, memorized motor actions have been compared to the suppression of novel motor actions. Multichannel EEG analyses of alpha power and alpha phase coherence were used. Healthy subjects were asked to inhibit the execution of either well-trained, memorized or untrained, novel sequential finger move- ments depending on the respective context. An increase of focal upper alpha activity at bilateral sensorimotor cortices was found during suppression of movements independent of whether these were memorized or novel. This represents a memory unspecific mechanism of motor cortical inhibition. In contrast, interregional phase synchronization between frontal and (left) central recording sites showed a differential effect with decoupling during suppression of memorized movements which was not the case with novel ones. Increase of fronto-central coupling at upper alpha frequency during retrieval of the memory trace and decrease during suppression of retrieval were obtained. This further supports the view of the functional relevance of upper alpha oscillations as a mechanism of context-dependent sustained inhibition of memory contents.
['Paul Sauseng', 'Christian Gerloff', 'Friedhelm C. Hummel']
Two brakes are better than one: the neural bases of inhibitory control of motor memory traces.