Background
Hartline, Haldan Keffer was born on December 22, 1903 in Bloomsburg, Pennsylvania, United States. Son of Daniel Schollenberger and Harriet Franklin (Keffer) Hartline.
Hartline, Haldan Keffer was born on December 22, 1903 in Bloomsburg, Pennsylvania, United States. Son of Daniel Schollenberger and Harriet Franklin (Keffer) Hartline.
Bachelor of Science, Lafayette College, Easton, Pennsylvania, 1923; Doctor of Science (honorary), Lafayette College, Easton, Pennsylvania, 1959; Doctor of Medicine, John Hopkins, 1927; Doctor of Laws (honorary), John Hopkins, 1969; Doctor of Science (honorary), University Pennsylvania, 1971; Doctor of Medicine (honorary), University Freiburg i/B, 1971; Doctor of Science (honorary), Rockefeller U., 1976; Doctor of Science (honorary), University Maryland., 1978; Doctor of Science (honorary), Syracuse University, 1979; Eldridge Johnson traveling research scholar, U. Leipzig and Munich, 1929-1931.
After attending the universities of Leipzig and Munich as an Eldridge Johnson traveling research scholar from the University of Pennsylvania, he returned to the United States to take a position in the Eldridge Reeves Johnson Foundation for Medical Physics at Penn, which was under the directorship of Detlev West. Bronk at that time. In 1940–1941, he was Associate Professor of Physiology at Cornell Medical College in New York City, but returned to Penn and stayed until 1949. Then he became professor of biophysics and chairman of the department at Johns Hopkins in 1949.
Hartline 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, because their visual systems are much simpler than those of humans and thus easier to study. He concentrated his studies on the eye of the horseshoe crab (Limulus polyphemus).
Using minute electrodes, 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.
Hartline thus built up a detailed understanding of the workings of individual photoreceptors and nerve fibres in the retina, and he showed how simple retinal mechanisms constitute vital steps in the integration of visual information.
Member NAS, American Physiological Society, American Philosophical Society, American Academy Arts and Sciences, Royal Society (foreign member), Biophysics Society, Optical Society American (honorary), Physiological Society (United Kingdom) (honorary), Phi Beta Kappa, Sigma Xi.
Married Mary Elizabeth Kraus, April 11, 1936. Children: Daniel Keffer, Peter Haldan, Frederick Flanders.