Experimental setup and instrumentation for measurement and preprocessing of EEG during voluntary goal-directed movements.

The widely used practice in the study of human complex voluntary movement organization is to record, measure and analyze EEG activity covering the period of both motor preparation and performance. The main strategy is to reveal EEG characteristics related to both cognitive and motor aspects of the action. To this end a special-purpose experimental set-ups are required providing precise enough measure of timing and characteristics of the movement in order to synchronize EEG changes time-locked to the phases of task performance. We describe an experimental set-up including a special-purpose device, which was designed for study of slow, continuous goal-directed movements. The implementation was aimed to provide (i) performance of complicated enough task in order to force the subject to concentrate his mental activity predominantly on the task; (ii) to control the successive stages of task performance. The advantages of the presented instrumentation was demonstrated by comparing power spectra of EEG segments long before and immediately prior to the movement performance. The instrumentation is flexible enough to be used in a large scale psychophysiological experiments.