Biosketch
Dana Ballard
obtained his Ph.D. degree from the University of California
at Irvine in 1974. During 1974-1975 he had a post-doctoral
appointment at the Laboratorio Tecnologie Biomediche in
Rome, Italy. Since 1975 he has been at the University
of Rochester in the Computer Science Department where
he has the rank of professor. He is the co-author with
Professor Brown of "Computer Vision", a standard text,
and has a new text "An Introduction to Natural Computation"
that will be published by MIT Press in 1997.
Ballard's current
research focus is in computational theories of the brain
that account for its real-time performance. In 1985 with
Chris Brown, he led a team that designed and built a high
speed binocular camera control system capable of simulating
human eye movements. Recently he has extended his interests
to the use of Virtual Reality equipment, both for robot
modeling and human behavioral studies.
The Role
of Working Memory in Behaviors
Computational
theories of the brain necessarily must have hierarchies,
wherein the brain can be seen as using different instruction
sets at different spatio-temporal scales. A central time
scale is that of one-third of a second. At this time scale,
the brain's neural instructions direct the physical resources
of its body. An example of these kinds of instructions
are those used to direct discrete eye-movements. Interpreting
experimental data from this perspective implies that subjects
select eye-movements in a special strategy to avoid loading
working memory. Keeping working memory load at a minimum
may reflect the structure of natural tasks. Studies of
task learning show that the amount of state information
needed at any instant is highly variable. This constraint
has important implications for the computational theories
of high-level behavior.
