Tapping with peripheral nerve block - A role for tactile feedback in the timing of movements

This study examines the impact of peripheral nerve block, that is, the elim ination of tactile feedback on synchronization performance. In a tapping ex periment in which subjects were instructed to tap in synchrony with an audi tory pacing signal, three different tasks were studied under conditions wit h and without peripheral nerve block: standard tapping with tactile contact , isometric tapping, and contact-free tapping. In addition, the maximum tap ping rate was registered both with and without peripheral nerve block. It w as found that the anticipatory error, usually observed in synchronization t asks, was affected by the peripheral nerve block in the standard tapping an d the isometric tapping task. In both tasks, local anesthesia led to an inc rease in asynchrony between the pacing signal and the tap. Performance rema ined unimpaired in those tasks in which tactile information was assumed to play a minor role (maximum tapping rate and contact-free tapping). The resu lts clearly demonstrate the importance of tactile feedback for the timing o f movements. The predictions of a model assuming a strong correlation betwe en the amount of sensory feedback and the size of the negative asynchrony i n synchronization tasks were examined and discussed.