Showing that all the biophysical and biochemical modifications which take place within the nervous system contribute in one way or another, to the development of informational and decisional processes, the author describes the specifics of those processes. One of them is represented by the relative symmetry of those processes, because informational and decisional processes taking place in the right hemisphere are not absolutely identical with those which take place in the left hemisphere. Therefore, we can talk about a true hemispherical asymmetry. That asymmetry concerns all the steps of informational and decisional processes beginning with the reception and transmission of signals, to the discovering of information, which are brought by the respective signals and as for as processing of discovered information, in view of the most adequate decision election. Finally, the asymmetry of informational and decisional processes, which are based on differences between the logical superstructure of the two cerebral hemispheres, is analysed.