ABSTRACT
This chapter explores the original problem of the effects of brain operations on intelligence. It presents an interpretation which fundamentally concerns the nature of intelligence, its normal development and its later decline with old age. The point on intellectual ability method is that the detection of intellectual defect, following brain injury, requires the test procedure and use of a control group. The major aspect of the problem of control method in studies is the difficulty of getting satisfactory anatomical and physiological data. If brain injury occurs in limited region of the brain, it would presumably remove a small number of transmission paths from each of a very large number of assemblies. The clinical evidence has indicated that there are two components in intelligence-test performance and in any intelligent behavior. One is diminished immediately by damage to brain, and amounts to a factor of heredity; one is related more to experience, consisting of permanent changes in organization of pathways in cerebrum.
