Distinction of different fingers based on induced beta frequencies
< >M i l l . i t n i v a c i i v i l v in the ramie of Ι4.Ϊ5 l l / is a i h a i . i f t c M s i k leahi ie ol the Kolandic area and in close l u n u i i M i . i l ιc l . i t ion to mulei lying cortical networks. \ lo \emcni or exen motor imagery can block or dv-sMiclirom/e central beta oscillations and results in a cnc t i inse i ihed beta Ι . Κ Γ ) close to the corresponding representation areas [ 1 3 ) . Al ter termination ol" the motor mental action the desynchronized beta oscillations d i N p l a v a last recovery or even a rebound above the icsimg lex el. This beta rebound or beta event-related svnchron i /a t ion l l . R S ) has the maximum about 700 ms a l t e r movement-offset and displays a somatotopic orgam/ation [13|. It xvas shown recently in a neuromagnetic study, that also electrical median nerve s t imula t ion results in a beta ERS localized over the hand representation area [12]. A similar beta ERS after median nerve stimulation was reported in the EEG as well [5]. I he goal ol this study was to investigate the frequency of induced beta oscillations after stimulation of each fingertip of one hand and to obtain an answer to the question whether the individual fingers can be differentiated by the frequency of the induced postst imulus beta oscillations. For this purpose we analyzed the induced beta oscillations in single trials by using the Matching Pursuit (MP) algorithm [4].