Statistical Detection of Movement Activities in a Human Brain by Moving Separation of Mixture Distributions*

Abstract

One of the most popular experimental techniques for investigation of brain activity is the so-called method of evoked potentials: the subject repeatedly makes some movements (by his/her finger), whereas brain activity and some auxiliary signals are recorded for further analysis. The key problem is the detection of points in the myogram that correspond to the beginning of the movements. The more precisely the points are detected, the more successfully the magnetoencephalogram is processed aiming at the identification of sensors that are closest to the activity areas.

This paper proposes a statistical approach to this problem based on mixtures models that uses a specially modified method of moving separation of mixtures of probability distributions (MSMmethod) to detect the start points of the finger’s movements. We demonstrate the correctness of the new procedure and its advantages as compared with the method based on the notion of the myogram window variance.