VEP And EMG Analysis In A Reaction Time Task

In this paper we describe an approach to localise the source of the variability of human manual reaction times (RT) within the multi-stage sensory and neuromuscular processing chain. For this purpose, we recorded visually evoked cortical EEG potentials (VEP) and the electromyogram (EMG) of a small hand muscle (which performed the motor response) simultaneously with the force response. Analysis on single trial level which requires sophisticated signal processing of these noisy electrophysiological signals for parameter estimation revealed central processing stages being the source of RT variability.