Inhibition and the control of behavior. From Gall to Freud via Phineas Gage and the frontal lobes.

In his On the Functions of the Brain and Each of Its Parts, Franz Joseph Gall proposed that significant behaviors resulted from certain independent, irreducible, and fundamental faculties or propensities. There seems to be nothing in his system for explaining how two or more faculties interact, especially how one comes to predominate over another, other than the implicit notion that the stronger will be manifested. This peculiarity of Gall's system is consistent with the predominately "excitatory" physiology of his time in which there was no place for an independent inhibitory process. Despite the experimental demonstration of inhibitory phenonema, the sensory-motor physiological theories in the last three quarters of the 19th century were similarly deficient. The lack is seen most clearly in the experimental and clinical literature on frontal lobe function, especially in relation to the kinds of changes seen in the Gage case. The deficiencies of sensory-motor physiology are also to be found in Freud's model of the mental apparatus and in his concept of inhibition via a lateral cathexis. In the paper an attempt is made to trace the historical sequence of these ideas and to make their experimental and theorectical basis explicit.