Neuropsychological studies in the USSR. A review (part II).

Abstract

Human neuropsychology is a new branch of psychological science that was developed at the borders of psychology and neurology. Its goal is to study the brain organization of mental processes and, especially, the higher forms of behavioral processes (1-9). The central problem of this branch of science is the of functions in the brain cortex. Studies in this problem started several decades ago, but its scientific solution is still in the future. Neuropsychology developed as a result of two basic issues: the progress of neurosurgery and a need of psychological science for a reliable knowledge of the cerebral mechanisms of the psychological processes. In the last few decades neurosurgery has made tremendous progress. About 40 years ago, the mortality after brain operations was very high-sometimes 60-70%; now, as a result of new techniques of surgery, treatment of brain edema, and new methods of resuscitation, the mortality does not exceed 8-10%. This means that precise and early local (or regional) diagnosis of the localization of cerebral lesions (e.g., tumor, hemorrhage, vascular disorder) has become a problem of utmost importance. The solution of this problem has certain limitations. Regular neurological methods (analysis of alteration of sensibility and movements, tone and reflexes, limitations of sight and fields of vision, etc.) can be used for a local diagnosis of only a limited part of the cerebral cortex (sensorimotor areas and their pathways). X-ray studies do not bring any precise results, and even the use of contrast methods for arteriography and electroencephalography have certain limits. The restricted limits of regular neurological symptoms is a result of some very important facts: lesions of the highest (secondary or tertiary) zones of the cortex-which are considered as specifically humnan parts of hemispheres-do not result, as a rule, in any elementary sensory or motor defects and remain inaccessible for classical neurological examination. They are associated with alterations of very complex behavioral processes (cognitive processes, elaboration of complex programs of behavior and their control), and that is why one has to establish new complex methods that could be used to study functional disorders evoked by their injuries. It is thus necessary to apply methods of neuropsychology for local diagnosis of lesions of these complex cortical zones.