The role of the right parietal region in a movement time estimation task.

Thirteen right-handed male students performed a time estimation task by pressing a button with their left or right hand for an interval of either 0.5 or 1.3 s. Thirty channels of EEG were recorded, with the right ear as reference. After transforming the raw EEG data into local average reference data, the topography of event related desynchronization (ERD) of the rhythm within the 10-12 Hz frequency band was studied by computing ERD maps separately for accurate and inaccurate performance. Statistical comparison of ERD maps for accurate and inaccurate movement (Wilcoxon test) resulted in significant differences for the right parietal region prior to movement onset, with a larger ERD before accurate movement.