(1910-1977), neurophysiologist William Grey Walter (also known as Grey Walter) was born in Kansas City, Missouri, on 19 February 1910 to journalist parents Karl Wilhelm Walter (1880-1965) and Minerva (Margaret) Lucrezia Hardy (1879-1953). The Walter family moved from the United States to Britain in 1915, where William remained for the rest of his life. He was educated at Westminster School (1922-1928), before taking the Natural Science Tripos at King’s College, Cambridge (1928-1931). He went on to pursue postgraduate research on nerve physiology and conditioned reflexes, gaining his MA in 1935. After completing his MA, Walter was invited to work at the Central Pathological Laboratory of the Maudsley Hospital, London, under neuropsychiatrist Frederick Lucien Golla (1877-1968). Since the late 1920s, Golla had become increasingly interested in the clinical applications of the burgeoning field of electroencephalography (EEG), the measurement of the electrical activity of the brain via electrodes placed on the scalp. Noting his skill in technical matters, Golla encouraged Walter to develop increasingly sophisticated EEG devices, and supported his application for a Rockefeller Travelling Fellowship to visit the Jena laboratory of German physiologist Hans Berger (1873-1941), widely credited as the founder of electroencephalography. Walter went on to achieve several key ‘firsts’ in electroencephalography, including the first detection of a cerebral tumour using the technique in 1936. Between 1936 and 1939, Walter expanded his research programme and took readings from hundreds of patients, focusing particularly on the electrical patterns of epilepsy. In 1939, Golla was invited to become director of the new Burden Neurological Institute, Bristol, an independent research unit specialising in the investigation and treatment of neurological, psychological, and psychiatric disorders, and invited Walter to become director of the Institute’s Physiology Department. At the Burden, Walter further developed his EEG apparatus, developing the automatic frequency analyser and the toposcope in 1943 and 1950 respectively. His research programme also became increasingly ambitious, with investigations into the cerebral effects of stroboscopic light beginning in 1947 and, later, the discovery of ‘contingent negative variation’ (CNV, or the ‘expectancy wave’) in the 1960s. Walter also played a key role in the professionalization of electroencephalography during this period, co-founding the journal Electroencephalography and Clinical Neurophysiology and organising meetings of the EEG Society (1943-1989). Outside of his clinical work, Walter became a key figure in early British cybernetics, the study of feedback, control, and communication systems in humans and machines that synthesised approaches from engineering, biology, and mathematics. He co-founded the Ratio Club, an informal dining and discussion group which provided a key social outlet for cybernetic enthusiasts, which met between 1949 and 1955. He also built several cybernetic devices in his spare time, the most famous of which were his robotic tortoises, or Machina Speculatrix, designed to function as simple models of the adaptable human brain. These received national attention when they were exhibited on television in 1950 and at the Festival of Britain in 1951. He also became a prolific public intellectual, writing 170 scientific publications, serving as an expert witness in court courses, appearing frequently on the BBC, and writing an immensely popular non-specialist text on his neuroscientific work, The Living Brain (1953). His work also gained a surprising popularity among counter-cultural artists during the 1950s and 1960s, including Beat writers William S. Burroughs and Allen Ginsberg, who saw Walter’s research as part of a broader investigation of human consciousness. Walter was married twice, first to Katharine Monica Ratcliffe in 1934 and then to Vivian Joan Dovey (1915-1980) in 1947, with whom he had one son, Timothy Walter (1949-1976). Walter and Dovey separated in 1960 and divorced in 1973. After their separation, Walter lived with Lorraine Josephine Aldridge (née Donn) until 1972. In 1970, Walter suffered severe brain damage following a road accident, forcing him to retire from full-time research work. He died of a heart attack in 1977.

(1904-1995), neurophysiologist Mary (Mollie) Agnes Burnston Brown Brazier was born in Weston-Super-Mare, Somerset on 18 May 1904. She was educated at Sidcot School, Somerset and Bedford College, Bedford, before studying physiology and biochemistry at the University of London, gaining her BSc in 1926 and Ph.D. in 1930. Her first major research project, conducted at the Maudsley Hospital, London, focused on electrical changes in the skin that occur in thyroid disease. This work received great acclaim, and was awarded the Gold Medal of the Institute of Electrical Engineers and the Van Meter Prize of the American Association for the Study of Goitre in 1934. Following this project, Brazier became increasingly interested in the electrical activity of the human nervous system. After receiving a Rockefeller Fellowship in 1940, Brazier moved from London to the Massachusetts General Hospital (MGH) in Boston, Massachusetts, where she took up a number of posts as a neurophysiologist in the Departments of Psychiatry, Anaesthesia, and Neurology. While her research in Boston covered a variety of subjects – including psychological selection processes, neurological injuries, and electromyography – Brazier increasingly specialised in electroencephalography (EEG, the measurement of the electrical activity of the brain), running the Hospital’s EEG Laboratory for much of the Second World War. In 1946, Brazier played a key role in persuading William Grey Walter (1910-1977), a neurophysiologist and EEG expert at the Burden Neurological Institute in Bristol, England, to come to Boston and demonstrate his new EEG frequency analyser device. The device remained in Boston, and helped to facilitate Brazier’s path-breaking computerised analyses of brainwave patterns. In 1961, Brazier left Massachusetts to join the Brain Research Institute at the University of California, Los Angeles (UCLA), where she was appointed Professor of Anatomy, Physiology and Biophysics. Here, she expanded her research on the electrical activity in the brain and nervous system, specialising in the use of computing methods to evaluate patients with epilepsy for surgical treatment. During her career, Brazier played a key role in expanding the international reach of several neuroscientific disciplines. She wrote a seminal textbook The Electrical Activity of the Nervous System in 1957, and was successively appointed Treasurer, Secretary, and finally President of the International Federation of Societies for Electroencephalography and Clinical Neurophysiology. She also wrote a number of texts on the history of neurophysiology, including A History of Neurophysiology in the 17th and 18th Centuries (1984) and A History of Neurophysiology in the 19th Century (1988). She continued writing in academic circles right up to her death, with her last essay published in the Journal for the History of the Neurosciences in 1993. Brazier married Leslie J. Brazier, an electrical engineer, in 1928, with whom she had one son. She died in Falmouth, Massachusetts, on 14 May 1995.

(1904-1972), electroencephalographer Robert S. Schwab was born in St Louis, Missouri in 1904. He trained in physiology at Cambridge University before qualifying in medicine at Harvard Medical School. He went on to specialise in neurology at the Boston City and Massachusetts General Hospitals, as well as training in neuropathology at the University of Munich and psychiatry at the Boston Psychiatric Hospital. In 1937, Schwab established and became director of the Brian Wave Laboratory at Massachusetts General Hospital, where he remained until his retirement in 1968. During his tenure, Schwab established the first technical training course in electroencephalography (EEG, the measurement of the electrical activity of the brain) to be supported by the United States Public Health Service, and conducted research on a number of topics including Parkinson’s disease and the use of EEG in establishing the criteria for death. Schwab also played a key role in the professional organisation of electroencephalography, serving as President for both the Eastern Association of Electroencephalographers and the American EEG Society and Vice-President of the International Federation of Societies for Electroencephalography and Clinical Neurophysiology. He also served as an editor of The EEG Journal throughout his career. Schwab was married twice, first to Dorothy Schwab (d.1971) and then to Joan Sheahan. Schwab died in Boston, Massachusetts on 6 April 1972.

(1884-1960), neurologist William Gordon Lennox was born in Colorado Springs, Colorado in 1884. He was educated at Colorado College, before applying unsuccessfully to Boston University Divinity School in 1909. After this rejection, Lennox instead pursued a medical degree at Harvard Medical School. After qualifying in 1913, Lennox spent four years as a medical missionary at Union Medical College in Beijing, China where he first encountered cases of epilepsy. The condition would later come to dominate his career. After returning from China, Lennox took up teaching and research positions at Harvard Medical School, where he remained until his retirement in 1958. While at Harvard, Lennox pioneered the use of electroencephalography (EEG, the measurement of the electrical activity of the brain) in the diagnosis and treatment of epilepsy alongside fellow neurologists and epileptologists Stanley Cobb (1887-1968), Erna Gibbs (1906-1987), and Frederic Gibbs (1903-1992). In his seminal text Epilepsy and Related Disorders (1960), published in the year of his death, Lennox argued that epilepsy was not a singular condition, but a constellation of neurological abnormalities, and outlined the EEG patterns for common seizure types to aid diagnosis. Lennox was also active in promoting international awareness of epilepsy and fighting long-standing and pervasive stigma towards the condition, and was described as the ‘Father of the Fight Against Epilepsy’ for his activism. Lennox played a key role in the creation and organisation of the American Epilepsy Society, the National Epilepsy League, the Epilepsy Federation, the United Epilepsy Society, and the Epilepsy Information Centre. Between 1935 and 1953, Lennox served as President (later Honorary President) of the International League Against Epilepsy. Lennox died in Boston, Massachusetts, on 22 July 1960.

(1901-1981), neurologist Derek Ernest Denny-Brown was born in Christchurch, New Zealand on 1 June 1901. He was educated at New Plymouth High School before qualifying in medicine at Otago University, Christchurch in 1924. Denny-Brown came to Britain the following year to study at Magdalen College, Oxford, before undertaking a research fellowship with neurophysiologist Sir Charles Scott Sherrington (1857-1952). After this, he became a medical officer and later a registrar at the National Hospital for Nervous Diseases and Guy’s Hospital, London. In 1935, he was appointed neurological consultant at both the National Hospital and St Bartholomew’s Hospital. Over the following decade, Denny-Brown held positions at Yale University and Boston City Hospital, and also served in the British Army during the Second World War (1939-1945). In 1946, he became James Jackson Putnam Professor of Neurology at Harvard University, where he remained until his retirement in 1967. During this period, he conducted important research on neurological diseases affecting muscular and cerebral functions. Denny-Brown married Sylvia Summerhayes in 1937, with whom he had four children. He died from cancer in Bethesda, Maryland on 20 April 1981.

The Mayo Clinic is an American medical practice and research centre in Rochester, Minnesota. The Clinic evolved out of the late nineteenth-century surgical partnership of physicians William James Mayo (1861-1939) and Charles Horace Mayo (1865-1939), both of whom helped to found St Mary’s Hospital, Rochester in 1899 with their father, William Worrall Mayo (1819-1911). The Clinic’s educational and research activities expanded significantly in the early twentieth-century following the Mayo brothers’ establishment of the Mayo Foundation for Medical Education and Research at the University of Minnesota in 1915.