Haldan Keffer Hartline
Hartline, Haldan Keffer, 1903–83, American physiologist, b. Bloomsburg, Pa., M.D. Johns Hopkins, 1927. From 1931 to 1949 (except for 1940–41), he was a researcher at the Eldridge Reeves Johnson Foundation for Medical Physics, Univ. of Pennsylvania. He was a professor at Johns Hopkins from 1949 to 1953, when he joined the faculty of the Rockefeller Institute (now Rockefeller Univ.). Hartline was a co-recipient of the 1967 Nobel Prize in physiology or medicine with George Wald and Ragnar Granit for their discoveries concerning the primary physiological and chemical visual processes in the eye. Hartline studied the eye of the horseshoe crab and determined that stimulation of one of the receptor cells in the eye is accompanied by depression of the nearby cells, resulting in enhanced contrast and shape perception.