Lobotomy was closely tied to changes in the neurological profession, first performed by a Portuguese neurologist and later popularized by an American one. As we have seen, the French neurological tradition as well as the growing competition between the fields of neurology, neurology, and psychiatry set the ground for the procedure's development. Changing perceptions of brain function in the early decades of the twentieth century contributed to neurologists' willingness to experiment with a surgical intervention for mental illness. The intellectual basis of a procedure designed to disrupt neural pathways connecting the frontal lobes and other cerebral area was based on neurological views of brain function and its relation to behavior. For Freeman, well versed in current neurological and pathological research, this approach to mental illness made perfect sense. His perception of the relations between the frontal lobes and mental illness was profoundly influenced by two streams of thought in contemporary neurology: localization and holism.

Localization theory held that the brain was constituted of distinct components in separate anatomical areas, which were responsible for clearly defined functions. This theory was developed in nineteenth-century neurology, strengthened in particular by research on aphasia. These early studies demonstrated how certain language deficits were caused by lesions in discrete areas in the brain. As a result, focal lesions could be tied to specific neurological signs.