Method of quantitative estimation of the degree of arbitrariness of the hand movements

The article presents a method for quantifying the randomness of arm movements. Habitual human voluntary actions contain an involuntary component. Even simple actions, for example the finger movement can not be performed with movement parameters - such as the amplitude or the frequency, fully controlled. When the experiment is repeated many times, the motor pattern is always different. N. Bernstein described this effect and called it "repetition without repetition". However, the observation of this effect does not give answers to the main questions: what is the cause in each case of this variation? How do we quantify the rates of voluntary and involuntary components in the movement? Human identity means the idea of the cause of actions, as pointed out by I. Sechenov, it is an illusion: the original cause of every action is always the external sensory excitation, because without it no thought is possible. Often extramental sensory stimuli can influence the person's behavior. This is important in situations related to the problem of choice in the political, social and domestic spheres. Actively developing neuroeconomics is applied orientation, based on the results of neurobiological research, obtained by modern research methods. We proposed a method consisting of statistical comparison of all possible pairs of the received samples and counting the number of matches (i.e. lack of statistically significant differences when comparing this pair of samples - k ) for the quantification of randomness of arm movements. The results indicate the variability of output indexes of motor functions, depending on the degree and the type of afferent influences (modality). The largest number of pairs of matching samples observed for voluntary arm movements - 11.6% of the total number, and the lowest at rest 3.2%, while afferentation under static load - 7.1%.