Edward Vaughan Evarts (March 28, 1926 – July 2, 1985) was an American

neuroscientist A neuroscientist (or neurobiologist) is a scientist who has specialised knowledge in neuroscience, a branch of biology that deals with the physiology, biochemistry, psychology, anatomy and molecular biology of neurons, neural circuits, and glial ...

. He pioneered single-unit recordings from the brains of awake, behaving monkeys.

Life

Evarts received his undergraduate degree at

Harvard College Harvard College is the undergraduate college of Harvard University, an Ivy League research university in Cambridge, Massachusetts. Founded in 1636, Harvard College is the original school of Harvard University, the oldest institution of higher lea ...

and an M.D. degree from

Harvard Medical School Harvard Medical School (HMS) is the graduate medical school of Harvard University and is located in the Longwood Medical Area of Boston, Massachusetts. Founded in 1782, HMS is one of the oldest medical schools in the United States and is consi ...

in 1948. Evarts undertook an internship at Boston's Peter Bent Brigham Hospital, worked with

Karl Lashley Karl Spencer Lashley (June 7, 1890 – August 7, 1958) was a psychologist and behaviorist remembered for his contributions to the study of learning and memory. A ''Review of General Psychology'' survey, published in 2002, ranked Lashley as the 61 ...

at Yerkes Laboratories of Primate Biology in Orange Park, Florida, and at the National Hospital for Nervous Diseases in London. After a residency in psychiatry at the Payne Whitney Institute in New York, Evarts joined NIMH in Bethesda, Maryland where he was appointed as head of the Section on Physiology at the Laboratory of Clinical Science and became chief of the Laboratory of Neurophysiology in 1970. Evarts remained in that position until he died, in his laboratory, July 2, 1985. Evarts started his neurophysiological research by conducting ablation studies of visual and auditory cortex in monkeys. He also studied effects of

LSD Lysergic acid diethylamide (LSD), also known colloquially as acid, is a potent psychedelic drug. Effects typically include intensified thoughts, emotions, and sensory perception. At sufficiently high dosages LSD manifests primarily mental, vi ...

and post-tetanic potentiation in the cat visual system. Evarts made his most significant contribution to the field of

neuroscience Neuroscience is the scientific study of the nervous system (the brain, spinal cord, and peripheral nervous system), its functions and disorders. It is a multidisciplinary science that combines physiology, anatomy, molecular biology, developme ...

and motor control by pioneering electrophysiological recordings from single cortical neurons in awake monkeys. In his early studies using this technique, he compared sleep and waking states. He then conducted experiments that involved single-unit recordings from sensorimotor cortex in monkeys performing operantly conditioned movements. He observed modulations in the activity of single neurons that reflected movement parameters. Based on these observations, he developed the concepts of "motor set" and "transcortical reflex". "Psychomotor set" describes neural activity that occurs when a motor action in response to a stimulus ("go-cue") is being prepared. "Transcortical reflex" describes the operation of motor cortex in the way similar to spinal reflexes that influence spinal motoneuron firing.

Influence

The work of Evarts gave rise to a new field in

. His followers use single electrodes and electrode arrays temporarily inserted or implanted in the brain to record brain signals during different types of behavioral and cognitive activity and thereby gain knowledge about how the brain works. The knowledge accumulated in this research recently resulted in creation of brain-computer interfaces—electronic devices that sample neuronal activity in the brain, decode its meaning and use decoded information to operate external devices, such as

robot A robot is a machine—especially one programmable by a computer—capable of carrying out a complex series of actions automatically. A robot can be guided by an external control device, or the control may be embedded within. Robots may ...

Prediction in 1956 concerning antipsychotic drugs and life expectancy

At a meeting in 1956 of the National Academy of Sciences, Evarts contended that antipsychotics such as the then new

chlorpromazine Chlorpromazine (CPZ), marketed under the brand names Thorazine and Largactil among others, is an antipsychotic medication. It is primarily used to treat psychotic disorders such as schizophrenia. Other uses include the treatment of bipolar di ...

would cause short-term benefits to patients, but at the cost of reducing life expectancy.book=Pharmageddon&page=155 by David Healy

References

External links

William Thomas Thach, Jr., "Edward Vaughan Evarts", Biographical Memoirs of the National Academy of Sciences (2000)
{{DEFAULTSORT:Evarts, Edward American neuroscientists 1926 births 1985 deaths Harvard Medical School alumni Behavioral neuroscientists Harvard College alumni Members of the National Academy of Medicine