Distinction of different fingers by the frequency of stimulus induced betaoscillations in the human EEG

Induced beta oscillations were studied in three normal subjects after mecha nical stimulation of each fingertip of the right hand. For stimulation shor t tactile stimuli of 10 ms duration were presented at intervals of 4 s. The electroencephalogram was recorded with 60 closely spaced electrodes and sa mpled at 256 Hz. For each subject the reactive beta band was determined by comparing 1-s power spectra. The largest beta power increase was found in t he range of 12-28 Hz on electrodes overlying the left-hand area. The Matchi ng Pursuit algorithm was applied to single trials data and the frequency of single 'atoms' determined. In one subject the little finger showed a signi ficant higher frequency as compared to the thumb. The difference in frequen cy was in the order of 1 Hz. (C) 2001 Elsevier Science Ireland Ltd. All rig hts reserved.