[Primary motor cortex as one of the levels of the construction of movements].

ABSTRACT

The data obtained during the recent decades led to revision of the dominant in neurophysiology view of primary motor cortex as "the cord area" which transfers the motor commands to the spinal cord. Contrary to this point of view, it was shown that MI primates neurons participate in all stages of organization of motor behavior and that the final postures of complex coordinated movements are represented in the MI map. Characteristics of movements controlled by MI revealed by currently available methods were predicted and explained by N.A. Bernstein about 70 years ago. According to his concept, there are some levels of the construction of movements that exist in the central nervous system. Area 4 (i.e. MI), which is one of them, appeared on the definite stage of evolution for resolving the particular movement tasks. In support of this conception we are showing that 1) MI controls the movements that differ from the movements of other levels by their characteristics (the mode of operating and the sense content); 2) some voluntary movements can be executed without participation of MI; 3) different motor areas of the cortex are coupled with different aspects of movement behavior.