Changes in local and distant EEG activities before, during and after the observation and execution of sequential finger movements

Aim of the study. - To consider cortical oscillations at local and distant/large scale levels during the time course of motor events under both an observation and an execution condition. Methods. - Local and distant changes in EEG cortical oscillations were respectively assessed by the Event-Related Desynchronization/Synchronization technique and the Synchronization Likelihood technique. Data collected prior to, during, and after observation and execution of complex sequential finger movements were used to investigate these changes. EEGs were recorded from 19 active sites across the cortex of 10 subjects. Sensorimotor activity was examined in alpha frequency bands. Results. - Local power changes and global inter regional synchronizations were two distinct phenomena, which occurred simultaneously and displayed different spatiotemporal patterns. Discussion and conclusions. - These findings demonstrate the complementary character of both analysis techniques. Results are discussed in tight of the recent findings from the cognitive and behavioural neuroscience literature. (C) 2009 Elsevier Masson SAS. All rights reserved.