Mental symptoms and therapeutic results after different types of frontal lobe operations in mental disorder

　 It is a great pleasure and privilege to speak before this distinguished audience at a famous university so far situated from my own in Stockholm.

　 Ever since Hippocratus and Plato assigned thought and feeling to the brain, this organ had been the subject of speculations by scientists. But brain research did not come into existence until the methods of natural science-unbiased observation, description and experiments-had broken through in the 19th century. Comparison between brains of animals and men showed that the most striking difference was to be found in the enormous growth of the frontal lobes. In the dog the frontal lobes represent 7％ of the total surface of the brain, in the chimpanzee 17％, while in men it represents no less than 29％.