[Influence of static muscle tension on acoustically evoked brain potentials, changes in skin resistance and bioelectric muscle activity].

Auditory evoked brain potentials (AEP), galvanic skin responses (GSR) and auditory evoked bioelectrical muscular responses were recorded in 16 male human subjects during voluntary isometric contraction of m. triceps brachii dexter. The electromygraphically controlled strength of muscular innervation corresponded to 20, 30, 40 and 50% of the maximal voluntary contraction. The trials were organized according to a change-over design. The following results could be obtained: The stepwise increase of the strength of muscular innervation effected an increase of the mean amplitude of auditory evoked EMG responses. The N1-P2 amplitudes of the AEP decreased with increasing strength of muscular innervation. The mean amplitude of the auditory evoked galvanic skin response was not changed significantly by the strength of muscular innervation, however, the spontaneous changes in galvanic skin resistance increased monotonously. Habituation effects were evident regarding amplitudes of AEP and GSR. The results indicate that muscular activity affects sensory information processing.