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July 1930

Brain Mechanisms and Intelligence. A Quantitative Study of Injuries to the Brain.

Arch NeurPsych. 1930;24(1):222-223. doi:10.1001/archneurpsyc.1930.02220130225023

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This monograph, the first to be issued by the Behavior Research Fund of the State of Illinois, takes up a topic of the utmost importance. It begins with an excellent discussion of the theories of intelligence held by the psychologic and neurologic schools. From this it is apparent that from both standpoints the problem is in confusion. The author attempts to solve the problem by experimentation with rats. The experiments include the training of rats in a variety of problems, either before or after destruction of parts of the cerebral cortex, to determine the influence of lesions on previously performed habits or on retention of habits formed after an injury.

From these experiments the conclusion is reached that the capacity to form habits is reduced by destruction of cerebral tissue, and that the reduction is roughly proportional to the amount of destruction. The same retardation in learning is produced by