Penfield’s Homunculus and Other Grotesque Creatures from the Land of If

Abstract

The neurosurgeon Wilder Graves Penfield (1891-1976) helped to develop a surgical treatment for epilepsy and used his results to investigate the functional organization of the brain. He was instrumental in founding the Montreal Neurological Institute at McGill University, which he directed from 1934 to 1960. There he studied, with his collaborators, the effects of stimulation and surgical ablation on different parts of the brain in order to localize their somatosensory functions. To visualize the results of this research, Hortense Pauline Cantlie drew images of a homunculus whose proportions reflected the extent of the cortical areas controlling different parts of the body. These images were published by Penfield in 1937; a modified version followed in 1950, opening the way for such developments as the diagrams of mammalian brains drawn by the neurophysiologist Clinton N. Woolsey in 1958. This article will reconstruct the history of Penfield’s map of the human brain, which was utilized in medical texts for many decades, but which eventually would be severely criticized.