Dr. William Newsome is sitting at his PC computer grumbling. “Do you know what IBM stands for?” Newsome asks in a slight Southern drawl. “It stands for ‘I’m Building a Mac’,” he quips, displaying quick-witted charm and ardent loyalty to the Macintosh operating system. Dr. Newsome, an associate professor of neurobiology at Stanford University, is known for being clever. Respected in the scientific community as a risk-taker and shrewd thinker, he has built his career on elegant experiments that have helped explain the neural basis of behavior.
Newsome grew up in a small town in Suwanee County, Florida, harboring a keen interest in science as a young boy after looking at protozoan under the microscope for the first time. He later pursued his interest in science at Stetson University, a small liberal arts school in north Florida. Newsome spent his first undergraduate years studying physics, but never forgot his boyhood fascination with biology and switched the focus of his studies his junior year. “It seemed to me that the three most interesting questions…at the time were: how does the brain work, how do genes work, and what is the origin of life?” Newsome recalls. He decided to apply for biology graduate school during his last year at Stetson, and worked hard to prepare. “I took quite a few chemistry and biology courses during my last year and a half ,” laughs Newsome. One biology professor took Newsome under his wing and gave him a yearlong biology tutorial. Newsome’s efforts proved fruitful when later that year he gained acceptance to California Institute of Technology in Pasadena, California where he completed a Ph.D.in biology in 1979.
Early Primate Research
Newsome narrowed his interests to studying the neural mechanisms of vision during his years at Caltech. He credits his Caltech mentors, Dr. John Allman and Dr. David Van Essen, with providing excellent guidance. It was under their tutelage, that Newsome worked on his first published study involving the anatomical connections between visual cortical areas in the two cerebral hemispheres (Newsome and Allman, 1980).
Later, as a post-doctoral student at the National Institutes of Health in Bethesda, Maryland, Newsome met Dr. Robert Wurtz, and together they continued to investigate the neural basis of vision. Newsome and Wurtz focused on motion processing in the visual cortex of monkeys. One of their early studies identified an area in the monkey’s brain, now called middle temporal visual area (MT), an area that is selectively involved in the analysis of visual motion (Newsome et. al, 1985). Their further studies investigating MT found that single neurons in that area selectively respond to either the direction or speed of a moving stimulus (Mikami, et. al, 1986).
Newsome joined the neuroscience faculty at Stanford University in 1988 and continued to research visual motion processing in monkeys. It was during this time that Newsome had “probably the single most exhilarating moment” of his career. He was working with Daniel Salzman, who at the time was a Stanford medical student, on a study recording the electrical activity of directionally selective neurons in visual cortex. Newsome and Salzman trained rhesus monkeys to respond differently to stimuli moving in different directions. They then recorded the electrical activity of MT neurons while the monkeys performed the direction discrimination task. “All of our studies up to that point had suggested that these neurons, deep in the central nervous system, might actually provide the information used by the monkey to judge the direction of motion in visual stimuli that we presented on a TV monitor,” Newsome recalls.
Next, Newsome and Salzman stimulated columns of ‘up’ cells or columns of ‘down’ cells while the monkey looked at a stimulus and tried to decide the direction of the motion. When stimulating an ‘up’ column of neurons in the monkey’s visual cortex, the monkey perceived most of the stimulus as moving upward even when the motion was actually downward. Similarly, when they stimulated a ‘down’ column, the monkey perceived the stimuli as moving downward despite its actual upward motion. By activating neurons artificially at precise points within the visual cortex, the researchers were able to shift the monkey’s conscious perceptual judgements (Salzman, et. al, 1992). Newsome remarks, “Those first few experiments were really a remarkable experience. We have done hundreds of these experiments now, but it still amazes me.”
Looking into the Future
Newsome and his colleagues are continuing work on the processing of visual information. Currently underway are studies investigating how visual information is processed as signals move from one cortical area to the next. Dr. Newsome’s lab is also working on understanding the process of sensorimotor integration, a process by which sensory information produces motor responses. “We would like to know how information in the sensory areas of the brain is transformed to signals that are appropriate for generating behavioral responses,” says Newsome.
Despite Newsome’s success with gaining insights into the monkey visual cortex, he recognizes the limitations of inferring from animal studies to make larger claims about humans. Were there a technology that could safely and non-invasively allow the electrical stimulation of the human brain with very high precision, Newsome acknowledges, ” certainly, we would be much closer to a…real science of consciousness…than we are now.”
Nevertheless, Newsome is optimistic about the future of neuroscience. He notes, “At its deepest level, …cognitive neuroscience will ultimately exert profound effects on our understanding of who we as human beings really are. What are the deepest sources of our behavior? How modifiable is behavior ultimately? How much freedom do we actually have, and to what extent is our freedom limited by the biology of the brain? These questions have been asked for millennia, but the day may be approaching, perhaps during the lifetime of today’s students, when we can start getting some real answers to such questions.”
Q: Where were you born?
A: Small town called Live Oak in Suwanee County, Florida.
Q: What were you interested in learning while you were growing up?
A: Almost everything. Developed a particular interest in science when I took biology in the 9th grade and looked at protozoans under the microscope for the first time.
Q: Where did you go to college? And what did you study there?
A: I went to Stetson University — a small liberal arts college in north Florida. I majored in physics, but I decided during my junior year that I really wanted to do biology in grad school, so I took quite a few chemistry and biology courses during my last 1.5 yrs. at Stetson.
Q: When did you start getting interested in your field and how did you go about learning more?
A: During my senior year in college I was applying to grad schools and thinking carefully about what sort of biology I wanted to study. It seemed to me that the three most interesting questions in biology at the time were 1) how does the brain work, 2) how do genes work, and 3) what is the origin of life? I applied to grad schools with strong programs in all three areas, but selected neuroscience in the end. The rest is history!
Q: Did you have any mentors? Other people or research that inspired you?
A: I have had several important mentors. Several members of the faculty at Stetson took a very close interest in my development. One biology professor, in particular, gave me a year-long independent tutorial in the basics of cell and molecular biology during my senior year to get me ready for graduate study in biology. This is the kind of thing that happens at small liberal arts colleges, which doesn’t happen often at large research universities. I also had two excellent mentors in graduate school at Caltech — my thesis advisor, Dr. John Allman, and Dr. David Van Essen. My postdoctoral advisor, Dr. Robert Wurtz at the NIH, influenced me tremendously, as did Dr. Tony Movshon of New York University, with whom I collaborated for several years. In many respects the post-docs and grad students in my lab continue to mentor me. Sometimes I think I learn more from them than they do from me.
Q: What was your first research break?
A: Uhh, I’m not sure what you mean. Do you mean my first publishable result? If so, it was a study I did in graduate school concerning the anatomical connections between visual cortical areas in the two cerebral hemispheres. It was a nice piece of work, though certainly not earth-shaking. That paper, published in 1980, is still cited occasionally.
Q: What projects are currently working on?
A: About half of my lab is working on issues related to the processing of visual information by visual areas of the cerebral cortex. We want to know how the electrical activity of neurons in the cortex determine what we see, and how information is processed as signals move from one processing stage to the next within the cortex. The other half of the lab is working on issues that we can loosely call ‘sensorimotor integration’. Basically, we would like to know how information in the sensory areas of the brain is transformed to signals that are appropriate for generating behavioral responses to the stimulus. We are particularly interested in perceptual judgments (is the motion upward or downward?) as a model of a simple ‘decision process’ operating in the brain.
Q: What is the current state of the research field that you are in now? Open questions in the field? (“holy grail”)
A: There are open questions on all sides. We know a lot about early stages of visual processing in the brain, but fundamentally we do not yet know how one distinguishes a face, for example, from a table or a chair. Thus the problem of ‘object recognition’ is a major open question. In another area, we are only beginning to get the first glimmers of how decisions are made within the brain. Recording from various cerebral cortical areas while monkeys perform discrimination tasks, we can find neural signals related to the sensory stimulus that comes in to the brain, and we can find signals that reflect the monkey’s decision in that they are appropriate for guiding the behavioral response. But exactly where and how the sensory signals are evaluated to reach a categorical decision is still quite mysterious. Further afield from my own specific interests, other investigators in systems and cognitive neuroscience studying with some success the neural correlates of short term memory, attention, and motor planning. Again, we are only beginning to gain insight into how the brain accomplishes these cognitive functions.
Q: How do you see your research affecting the rest of society?
A: Cognitive neuroscience will have tremendous effects on society. Understanding how the brain produces cognitive functions is essential to understanding what goes wrong in neurological and psychiatric diseases that produce disorders of cognition. Deeper understanding of the biological basis of cognition will produce new therapies for learning disabilities and communication disorders. Understanding how brains solve the problem of ‘object recognition’ will help in the design of intelligent ‘seeing’ machines, and the commercial potential of such machines is vast. At the deepest level, however, cognitive neuroscience will ultimately exert profound effects on our understanding of who we as human beings really are. What are the deepest sources of our behavior? How modifiable is behavior ultimately? How much freedom do we actually have, and to what extent is our freedom limited by the biology of the brain? These questions have been asked for millennia, but the day may be approaching, perhaps during the lifetime of today’s students, when we can start getting some real answers to such questions.
Q: What is one of the most interesting moments in your career?
A: Probably the single most exhilarating moment was an experiment that I was doing with Daniel Salzman, who was at the time a Stanford Medical student spending a research year in my laboratory. For some time we had been studying the activity of directionally selective neurons in the visual cortex. These neurons ‘respond’ optimally (that is generate a large number of electrical impulses) to motion in a particular direction. Neurons that ‘prefer’ a particular direction of motion are clustered together in small structures called ‘cortical columns’. We had trained rhesus monkeys to perform direction discrimination tasks and had recorded the electrical activity of these neurons while the monkeys performed the task. All of our studies up to that point suggested that these neurons, deep into the central nervous system, might actually provide the information used by the monkey to judge the direction of motion in visual stimuli that we presented on a TV monitor. The experiment that Daniel and I did was to electrically stimulate a column of ‘up’ cells or ‘down’ cells while the monkey was looking at a stimulus and trying to decide the direction of motion. The electrical stimulating currents were tiny (about 10 millionths of an ampere) because the columns are very small (about 100 microns). Amazingly, when we stimulated an ‘up’ column, the monkey made a large excess of ‘up’ decisions, even when the motion was actually downward. When we stimulated a ‘down’ column, the opposite occurred. Thus we could shift the monkeys conscious, perceptual judgments at will simply by activating neurons artificially at precise points within the cerebral cortex. Those first few experiments were really a remarkable experience. We have done hundreds of these experiments now, but it still amazes me.
Q: What do you like to do with your non-research time?
A: Read history, current events. Hike. Landscape photography.
Q: If someone could invent any kind of technology, what would you like it to be and why?
A: I would like to have a device that would allow me to electrically stimulate the human brain at very fine spatial and temporal resolution–safely and non-invasively. If we could have human subjects report to us their sensations and experiences that accompany activation of specific, functionally identified neural circuits within the cerebral cortex, a real science of consciousness might become possible. Certainly, we would be much closer to it than we are now.
Q: What books would you recommend that people beginning to get interested in neuroscience should read?
A: Eye, Brain and Vision by David Hubel is a fun place to start. The Emotional Brain by Joseph LeDoux is pretty well done. Memory and Brain by Larry Squire is good. A fine introductory textbook to the entire field is Neuroscience by Bear, Connor and Paradiso. For the more mathematically and technically inclined, Foundations of Vision by Brian Wandell of the Stanford Psychology Department is excellent.