Wilder Penfield
Wilder Graves Penfield was an American-Canadian neurosurgeon. He expanded brain surgery's methods and techniques, including mapping the functions of various regions of the brain such as the cortical homunculus. His scientific contributions on neural stimulation expand across a variety of topics including hallucinations, illusions, dissociation and déjà vu. Penfield devoted much of his thinking to mental processes, including contemplation of whether there was any scientific basis for the existence of the human soul.
Life and career
Early life and education
Born in Spokane, Washington, on January 26, 1891, Penfield spent most of his early life in Hudson, Wisconsin where he attended the Galahad school. He played football for the Galahad team and later assisted coaching them. He later studied at Princeton University, where he was a member of Cap and Gown Club and played on the football team. After graduation in 1913, he was hired briefly as the team coach. In 1915 he obtained a Rhodes Scholarship to Merton College, Oxford, where he studied neuropathology under Sir Charles Scott Sherrington. After one term at Merton, Penfield went to France where he served as a dresser in a military hospital in the suburbs of Paris. He was wounded in 1916 when the ferry he was aboard, the SS Sussex, was torpedoed. The following year, he married Helen Kermott, and began studying at the Johns Hopkins School of Medicine, attaining his medical degree in 1918; this was followed by a short period as a house surgeon at the Peter Bent Brigham Hospital in Boston. Returning to Merton College in 1919, Penfield spent the next two years completing his studies; during this time he met Sir William Osler. In 1924, he worked for five months with Pío del Río Hortega characterising the type of glial cells known as oligodendroglia. He also studied in Germany with Fedor Krause and Otfrid Foerster, as well as in New York City. In 1928, during the 6 months he spent in Germany with Foerster, he learned how to use local anesthesia to keep brain surgery patients awake.Medical career
After taking a surgical apprenticeship under Harvey Cushing, he obtained a position at the Neurological Institute of New York, where he carried out his first solo operations to treat epilepsy. While in New York, he met David Rockefeller, who wished to endow an institute where Penfield could further study the surgical treatment of epilepsy. Academic politics amongst the New York neurologists, however, prevented its establishment in New York, so, in 1928, Penfield accepted an invitation from Sir Vincent Meredith to move to Montreal, Quebec, Canada. There, Penfield taught at McGill University and the Royal Victoria Hospital, becoming the city's first neurosurgeon.In 1934, Penfield, along with William Cone, founded and became the first director of the Montreal Neurological Institute and Hospital at McGill University, established with the Rockefeller funding. That year, he also became a British subject.
Penfield was unable to save his only sister, Ruth, who died from brain cancer, though complex surgery he performed added years to her life.
Penfield was elected a Foreign Honorary Member of the American Academy of Arts and Sciences in 1950 and retired ten years later in 1960. He was a member of the United States National Academy of Sciences and the American Philosophical Society. He was appointed to the Order of Merit in the 1953 New Year Honours list. He turned his attention to writing, producing a novel as well as his autobiography No Man Alone. A later biography, Something Hidden, was written by his grandson Jefferson Lewis.
In 1960, the year he retired, Penfield was awarded the Lister Medal for his contributions to surgical science. He delivered the corresponding Lister Oration, "Activation of the Record of Human Experience", at the Royal College of Surgeons of England on April 27, 1961. In 1967, he was made a Companion of the Order of Canada and, in 1994, was posthumously inducted into the Canadian Medical Hall of Fame. Much of his archival material is housed in the Osler Library at McGill University.
Later life
In his later years, Penfield dedicated himself to the public interest, particularly in support of university education. With his friends Governor-General Georges Vanier and Pauline Vanier, he co-founded the Vanier Institute of the Family "to promote and guide education in the homeman's first classroom." He was also an early proponent of childhood bilingualism.Penfield died on April 5, 1976, of abdominal cancer at Royal Victoria Hospital in Montreal. He and his wife, Helen, had their ashes buried on the family property in East Bolton, Quebec on Sargent's Bay, Lake Memphremagog.
Scientific contributions
Neural stimulation
Penfield was a groundbreaking researcher and original surgeon. His development of a neurosurgical technique using an instrument known as the Penfield dissector, which produced the least injurious meningo-cerebral scar, became widely accepted in the field of neurosurgery and remains in regular use. With his colleague Herbert Jasper, he invented the "Montréal Procedure" in which he treated patients with severe epilepsy by destroying nerve cells in the brain where the seizures originated. Before operating, he stimulated the brain with electrical probes while the patients were conscious on the operating table, and observed their responses. In this way he could more accurately target the areas of the brain responsible, reducing the side-effects of the surgery.This technique also allowed him to create maps of the sensory and motor cortices of the brain showing their connections to the various limbs and organs of the body. These maps are still used today, practically unaltered. Along with Herbert Jasper, he published this work in 1951 as the landmark Epilepsy and the Functional Anatomy of the Human Brain. This work contributed a great deal to understanding the localization of brain function. Penfield's maps showed considerable overlap between regions a feature which he put down to individual variation in brain size and localisation: it has since been established that this is due to the fractured somatotopy of the motor cortex. From these results he developed his cortical homunculus map, which is how the brain sees the body from an inside perspective.
Penfield reported that stimulation of the temporal lobes could lead to vivid recall of memories. Oversimplified in popular psychology publications, including the best-selling I'm OK – You're OK, this seeded the common misconception that the brain continuously "records" experiences in perfect detail, although these memories are not available to conscious recall. Reported episodes of recall occurred in less than five percent of his patients, though these results have been replicated by modern surgeons. Penfield's hypothesis on this subject was revised in 1970.
Hallucinations
Penfield's scientific contributions go past the somatosensory and the motor cortices; his extensive work of the functions of the brain also included charting the functions of the parietal and temporal cortices. Of his 520 patients, 40 reported that while their temporal lobe was stimulated with an electrode they would recall dreams, smells, visual and auditory hallucinations, as well as out-of-body experiences. In his studies, Penfield found that when the temporal lobe was stimulated it produced a combination of hallucinations, dream, and memory recollection. These experiences would only last as long as the electrode stimulations were present on the cortex, and in some cases when patient experienced hallucinatory experiences that evoked certain smells, sensations of flashing light, stroking the back of their hand, and many others. Other stimulations had patients experiencing déjà vu, fear, loneliness, and strangeness. Certain areas of patients' temporal lobes were stimulated with an electrode in order to experience memories. Penfield called these perceptual illusions interpretive responses. According to Penfield, when the temporal lobe was stimulated there were two types of perceptions experienced by patients:- Experential experience – where the patient recorded hearing a song, or seeing a flash of light.
- Strip experience – The recall seems familiar to the patient and comes from the patient's past even though the patient may not be able to pinpoint the exact occasion. The recall of a memory or memories could reinforce the emotion tied to the experience.