2008 Karl Spencer Lashley Award

Spring General Meeting
Eric Knudsen

The American Philosophical Society awarded the 2008 Karl Spencer Lashley Award to Eric Knudsen. The citation read “in recognition of his comprehensive study of visual and auditory perception in the owl and for his elucidation of how the auditory map is calibrated by the visual system during development.” The award was presented by the Society’s President, Baruch S. Blumberg, Fox Chase Distinguished Scientist at the Fox Chase Cancer Center and Distinguished Scientist at NASA Fundamental Space Biology.

The Karl Spencer Lashley Award was established in 1957 by a gift from Dr. Lashley, a member of the Society and a distinguished neuroscientist and neuropsychologist. The award is made in recognition of work on the integrative neuroscience of behavior. At the time of his death, Dr. Lashley was Emeritus Research Professor of Neuropsychology at Harvard University and Emeritus Director of the Yerkes Laboratories of Primate Biology in Florida. Lashley's contemporaries considered his experimental work as daring and original. His entire scientific life was spent in the study of behavior and its neural basis, or as he phrased it: “the discovery of principles of nervous integration which are as yet completely unknown”. Lashley’s famous experiments on the brain mechanisms of learning, memory and intelligence helped inaugurate the modern era of integrative neuroscience.

Eric Knudsen received a Ph.D. at the University of California, San Diego, and following a postdoctoral fellowship at Cal Tech joined the faculty at Stanford University School of Medicine where he is currently Professor of Neurobiology. In his postdoctoral work, Dr. Knudsen discovered a map of auditory space in the barn owl’s brain. This map consists of neurons that respond only to sounds coming from particular directions. Because space is not topographically mapped in the cochlea, the map of auditory space must be centrally synthesized. After Knudsen established his laboratory at Stanford, he studied the relationships between the maps of auditory and visual space. He quickly found that the auditory space map projects to the optic tectum to give rise to a bimodal map in which each neuron responds to both auditory and visual stimuli located in the same spatial coordinates (receptive field). Thus, the brain creates an auditory space map by computation in order to conform to the same coordinate system that the visual system uses. He cleverly used the bimodal map to explore the mechanisms by which the auditory map is calibrated during ontogeny. In his most incisive experiment, he let young owls wear a pair of distorted glasses to show how the auditory receptive fields of bimodal neurons become aligned with the displaced visual receptive fields. He and his students have identified the site of plasticity for this process. His group has made seminal contributions to two other aspects of sound localization; one is the discovery of a motor map for the control of head turning and the other concerns the role of the forebrain in sound localization. His recent studies of the role of attention in sound localization have opened up a new frontier to explore.

The selection committee consisted of Larry R. Squire (chairman), Distinguished Professor of Psychiatry, Neurosciences and Psychology at the University of California, San Diego School of Medicine and Research Career Scientist at the VA Medical Center, San Diego; John E. Dowling, Gordon and Llura Gund Professor of Neurosciences at Harvard University; and Richard F. Thompson, Keck Professor of Psychology and Biological Sciences at the University of Southern California.