| VOL. 23, NO. 23||MAY 20, 1998 |
Chemist Bruce Berne, Psychologist Norma Graham Elected to National Academy of Sciences
|Bruce Berne. Record Photo by Joe Pineiro.|
BY BOB NELSON
wo Columbia faculty membersBruce Berne, a theoretical chemist and pioneer in molecular dynamics, and Norma Graham, a mathematical psychologist who has elucidated the visual sensehave been elected to the National Academy of Sciences.
Membership in the Academy is one of the highest honors that can be accorded a U.S. scientist. The Apr. 28 announcement of 60 new members in recognition of their distinguished and continuing achievements in original research brings the current Columbia membership to 26.
The Academy, a private organization, was established in 1863 by a Congressional act that charges it to advise the federal government on any matter of science or technology.
Berne, professor of chemistry, is a well-known expert in theoretical chemistry and in computer simulations of chemical events. He was a pioneer in the development of molecular dynamics, the method used to simulate chemical reactions on computers, and was the first to apply the method to simulate molecules in condensed states of matter. He has also made major contributions to the theory of chemical reaction rates and to the study of dynamic processes in clusters, liquids and liquid crystals. He invented major new Monte Carlo and molecular dynamics techniques used in computer simulations.
The Columbia chemist has also made important contributions to the field of dynamic laser light scattering, and, with Robert Pecora of Stanford, wrote a highly regarded book on the subject. The analysis of how laser light scatters from chemical and biological systems gives researchers information about how fast particles diffuse from one part of a system to another.
Berne earned the B.S. in chemistry from Brooklyn College in 1961 and the Ph.D. in chemical physics from the University of Chicago in 1964. After a year as a NATO Postdoctoral Fellow with Ilya Progine at the Université Libre de Bruxelles, he joined the Columbia faculty in 1966. Previous awards include an Alfred P. Sloan Foundation Fellowship (196870), a Guggenheim Fellowship (197273), an Alexander von Humboldt Senior U.S. Scientist Award (1992) and the American Chemical Societys National Award in Theoretical Chemistry (1995). He has been a Fellow of the American Physical Society since 1977 and was elected a Fellow of the American Academy of Arts and Sciences in 1995. He has published three books and more than 220 research papers.
Graham, professor of psychology, is one of a handful of scientists who in the 1970s developed the concept of spatial frequency channels in human vision and experimentally demonstrated their existence. Spatial frequency is, approximately speaking, the number of visual elements per unit distance, so an area in a visual scene filled with many fine stripes or with a fine-grained texture is an area of high spatial frequency. It turns out that certain of the brains neurons are sensitive to visual scenes with higher or lower spatial frequencies.
Other experimenters have shown that different channels or analyzers in the human visual system are sensitive to differences on other visual dimensions as well, such as different orientations and directions of motion. Her book, Visual Pattern Analyzers (1989), summarized this research and presented a general mathematical model integrating it. The information gathered by the eye is sorted into some 20 to 40 different modules in the brain, all of which are needed to resolve a visual scene; these visual pattern analyzers are probably neurons at the lowest level of the brain concerned with vision. She is currently building on this knowledge to increase our understanding of middle-level visual processes.
Graham earned the B.S. in mathematics from Stanford in 1966 and the Ph.D. in psychology from the University of Pennsylvania in 1970. She was a postdoctoral researcher in neurophysiology at Rockefeller University, and joined the Columbia faculty in 1972. She was elected to the Society of Experimental Psychologists in 1983 and to the American Academy of Arts and Sciences in 1993. She became a Fellow of the American Psychological Association in 1992 and of the Optical Society of America in 1996. Her current research is supported by a National Eye Institute Grant (1995-99). In addition to her 1989 book, she is the author or co-author of 44 research papers and book chapters.