Biographical Memoirs Volume 59 (1990) / Chapter Skim
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Haldan Keffer Hartline
Haldan Keffer Hartline
Pages 196-213
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From page 197... ...
Hartline's four major accomplishments were all "firsts" in their respective fields: With Clarence H Graham he recorded the activity of single optic nerve fibers.
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From page 198... ...
surely influenced his choice of experimental research in biology as his lifelong career. Upon completion of his studies at Bloomsburg in 1920, Hartline spent the summer at the marine laboratory in Cold Spring Harbor, I,ong Island, taking a six-week course in comparative anatomy.
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From page 199... ...
Drawn to these disciplines, he went so far as to consider a career in either one or the other. On a ~ohnson Research Scholarship from the Elciridge Reeves Johnson Foundation, he went to Germany to study uncler Arnold Sommerfelct at Munich and uncler Werner Heisenberg at Leipzig.
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From page 200... ...
Hervey and instrument maker Walter Biclerlich provided valuable support services. ~ first met Hartline in 1950 when ~ joined his laboratory on a one-year National Research Council fellowship.
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From page 201... ...
The compound eye of this venerable animal, with its large photoreceptors and long optic nerve, was ideally suited for this study, and in 1932 they were able to record the activity of single optic nerve fibers for the first time. Their research showed that impulses transmitted by an optic nerve fiber are essentially iclentical and that information about the intensity of light incident on the photoreceptor is coaled in terms of the rate of discharge of impulses rather than the shape or amplitucle of incliviclual impulses.
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From page 202... ...
The single-handed investigations, mainly on the vertebrate retina, of those years are per~ · · ~aps nits most s~gn~hcant contra button to science. With his exquisite microctissection technique, Hartline was able to isolate single optic nerve fibers of the vertebrate retina and, for the first time, record their activity.
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From page 203... ...
Simultaneous records of the propagated impulses in the optic nerve suggested that this retinal action potential might be the generator of the impulses. When micropipette electrocles with tips small enough to penetrate cells were developed, opening the generator potential to direct stucly, Hartline's earlier interest in this hypothesis was rekinclled.
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From page 204... ...
We were able with a pair of simultaneous equations to express the reciprocal interactions between two photoreceptor units in the steady state. Although these equations were strongly nonlinear overall, they were, as Hartline put it, "mercifully, piece-wise linear, to a good approximation." These so-called "Hartline-Ratliff equations" actually based upon, and testable by, direct electrophysiological measurements provided the first mathematical description of the integrative activity of a real neural network.
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From page 205... ...
Knight realized that the Limulus eye appeared to be a "timeinvariant linear system" that could be treated as a system of linear transducers, and that the several transductions could all be characterizes! by transfer functions.
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From page 206... ...
Howell Awarcl in Physiology. I:xperimental and physiological psychologists were among the first to recognize the importance of his later work to an understanding of human visual perception, and the Society of Experimental Psychologists awarcled him the Howard Crosby Warren Medal in 1948.
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From page 207... ...
Their three sons Daniel Kepler, Peter Halcian, and Frederick Flanders tutored by their father as he had been by his all became biologists. When Hartline accepted a position at Johns Hopkins in 1949, the family purchased a house near Hydes, Maryland, about twenty miles from Baltimore.
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From page 208... ...
He specifically requested that there be no official memorial service or organized tribute to him at The Rockefeller University, suggesting rather that one of the University concerts—which he had enjoyed} so much over so many years would be an appropriate memorial, bringingjoy to others rather than sorrow. On March 7, 1984, the Stuttgart Chamber Orchestra, with Karl Munchinger conducting, played to a full house in a performance dedicated to Keffer Hartline's memory.
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From page 209... ...
:468-73; Ragnar Granit and Floyd Ratliff, "Haldan Keffer Hartline, 1903-1983," Biographical Memoirs of Fellows of the Royal Society, 31~1985~:262-92; and Floyd Rashly, "Haldan Keffer Hartline (1903-1983) ," Year Book 1984 (Philadelphia: American Philosophical Society)
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From page 210... ...
The response to single optic nerve fibers of the vertebrate eye to illumination of the retina.
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From page 211... ...
Spatial summation of inhibitory influences in the eye of Limulus, and the mutual interaction of receptor units.
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From page 212... ...
Lange. Variability of interspike intervals in optic nerve fibers of Limulus: Effect of light and dark adaptation.
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From page 213... ...
Inhibitory interaction in the retina of Limulus. In: Handbook of Sensory Physiology, VII/2, Heidelberg: SpringerVerlag, pp.
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