Starting with Phineas Gage.
AMERICA, 1847: a highly competent and, by all accounts, pleasant manual laborer of Irish extraction named Phineas Gage is involved in rock blasting operations in mountainous terrain. In the course of one sadly uncontrolled explosion, an iron bar is picked up by the force of the blast and driven clean through the front part of his head. Phineas is sent flying, but, to everybody’s surprise, he survives the removal of the protruding bar. As he recovers, however, it is observed that his personality has dramatically changed, though his memory and intelligence remain apparently unaffected. In 1868, a physician named Harlow from Boston writes about him: “His equilibrium, or balance, so to speak, between his intellectual faculties and animal propensities seems to have been destroyed. He is fitful, irreverent, indulging in the grossest profanity (which was not previously his custom), manifesting but little deference for his fellows, impatient of restraint or advice when it conflicts with his desires.” The now extremely rude Phineas Gage is an object of immense medical interest, for it seems clear, from his somewhat crude experience of psychosurgery, that one can alter the social behavior of the human animal by physically interfering with the frontal lobes of the brain.