Haldan Keffer Hartline, American Physiologist

Haldan Keffer Hartline (December 22, 1903 - March 17, 1983) was an American physiologist. He became professor of biophysics and chairman of the department at Johns Hopkins in 1949. He joined the staff of Rockefeller University, New York City, in 1953 as professor of neurophysiology. Hartline investigated the electrical responses of the retinas of certain arthropods, vertebrates, and mollusks. He concentrated his studies on the eye of the horseshoe crab (Limulus polyphemus). Using minute electrodes in his experiments, he obtained the first record of the electrical impulses sent by a single optic nerve fibre when the receptors connected to it are stimulated by light. He found that the photoreceptor cells in the eye are interconnected in such a way that when one is stimulated, others nearby are depressed, thus enhancing the contrast in light patterns and sharpening the perception of shapes. He showed how simple retinal mechanisms constitute vital steps in the integration of visual information. He who was a co-winner (with George Wald and Ragnar Granit) of the 1967 Nobel Prize in Physiology or Medicine for his work in analyzing the neurophysiological mechanisms of vision. He died in 1983 at the age of 82

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Biophysicist Biophysics Haldan Hartline Laureate Mechanisms Neurophysiologist Nobelist Physiologist Recipient Vision

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