Abstract: Some results accquired in the past in experements on cases of Split-Brain, Right-Hemispherictomy and normal subjects were analysed and re-analysed in this paper. Simultaneously, the problem with the mechanism ofthe coordination activities between the two hemispheres was also discussed. On the basis of our experemental data, we also attempted to suggestthat there may be two possible models of the coordination activities in thebrain. (1) Two hemispheres work in coordination; (2) Two hemisphereswork in interference. After conscientionsly reading a large number of literature, we sensedthat it is inappropriate to take the arithmetic mean of the experemental dataas the indication of the lateral dominance of the brain. According to the ectorial nature of experemental data obtained throughunilateral visual field, we propose that: (1) To make the vector difference of the data from both left and rightvisual fields as the indication of the coordinate level between the two hemi-spheres. (2) To make the angular dfference between the vector value from LVF and RVF as the indication of the relative domination of the right or leftvisual field in a recognizing activity.

Key words: functional lateralization of the brain, coordinational activity between the two hemispheres, split-brain, dominanthemisphere, vector