Movement Related Potentials in Spontaneous and Provoked Thumb Movement

Abstract

Listen

Translate article

In order to get better insight in the brain electrical activity generated during the preparatory and executive phases of body movement we recorded the movement related evoked potentials (MREP) in three different experimental conditions. First, in the voluntary movement, then in the condition where the movement was performed as a reaction to acoustical signal and finally, in the condition where two different tones where presented and the movement was made after the target one (choice reaction). In both cases the reaction time was also measured. The obtained results clearly showed that apparently equal movements where accompanied with different cerebral dynamics. The self paced movement preparatory phase, reflected in bereitschaft potential (BP) and negative slope potential (NS), lasts longer. The activity was located in the temporal brain region. In the executive phase motor potentials (MP) were generated in parietal region and also in temporal region where motor cortex areas are situated. In the second experiment preparatory phase was shorter. The activity was located in the frontal brain region in the first moment and after that it caught the hole left half of the brain. The bigger influence had executive phase with motor potentials (MP). The majority of activity was situated in the left temporal brain region where three the most conspicuous areas of activity were found. Amplitudes in this part were much higher then in the self paced movement. The results of the third experiment showed that reaction time was longer. This was visible from the moments of the activations of the same brain regions compared with their activations in the second experiment. Longer reaction time can be explained with the influence of the cognitive component that was needed because of the complexity of the task. In the third experiment amplitudes were even higher than in the second experiment.