One on One with... Tom Albright
Since high school, Tom Albright has been fascinated by how we see. That fascination led to his undergraduate studies in experimental psychology because at the time that's where most efforts to find out how the visual system functioned were being done. But by the time he entered graduate school, new techniques to study vision through neurobiology had begun to emerge, so he switched his focus to neuroscience. Today Albright directs the Vision Center Laboratory at the Salk Institute, and his research into the mechanics of visual information processing is at the forefront of the field. He has received numerous honors for his work, including membership in the National Academy of Sciences; he is also a fellow of the American Association for the Advancement of Science. Last month, a $2 million gift from Conrad Prebys, a Salk trustee, along with a matching $1 million gift from Joan and Irwin Jacobs, established the Conrad T. Prebys Endowed Chair in Vision Research. Albright is the first holder of the chair.
Your research is at the nexus of vision, perception and consciousness. How does what we see become part of our consciousness?
Broadly speaking, the visual system works in three stages that take place from the retina through the visual cortex. The first stage breaks down the visual input into a number of qualitatively different attributes—brightness, color, texture, movement, distance. The second stage takes that information and puts it back together with a structure to it, a picture of the scene before you. The third stage is to assign meaning and emotional content, which enables recognition. This latter stage taps into your prior experiences with the world. And this is where vision becomes really interesting because the things you sense are no longer simply dependent on signals coming up from the retina, but they're heavily dependent upon what you have seen in the past, on your memories. This final stage comprises your conscious experience of the world.
How does our brain process all that visual information?You open your eyes in the morning and close them at night, and during that time you acquire an enormous amount of information. A lot of that information is irrelevant to your needs and goals, and you ignore it, focusing instead on those things that are critical for your understanding of the world around you. In this sense, vision acts like an adjustable filter that continually fine-tunes the flow of information ascending from the retina and descending from the memory store, the part of our brain where memories are preserved. This tuning or adaptive plasticity of visual sensitivity optimizes performance of the system for the environment we happen to be in—much like one might differently tune a car's engine to drive on city streets versus highways. It's something our laboratory has been looking at for the last few years.
What is the frontier of your field today?
The frontier today involves efforts to figure out how vision actually works. Based on our experiments, I can tell you a lot about the behavior of different classes of cells in the visual cortex, and I can draw compelling correlations between neuronal behavior and perception. I might even be able to convince you that the neuronal signals we record are the cause of specific perceptual states. But until recently, we've known very little about how all of this actually works. This lack of mechanistic knowledge largely reflects limitations of traditional techniques. But there is a revolution afoot today; the fields of molecular biology and genetics have provided us with fabulous new ways to probe the neuronal components of vision with unprecedented precision. For example, we can now manipulate the activity or precisely trace the connections of specific populations of brain cells. From these data we can begin to develop detailed pictures of the cellular mechanisms that enable us to see—to hit a baseball, to find our car in the parking lot or to recognize the face of our lover.
You spend a lot of time thinking about how vision works. Does it influence how you look at the world?
I'm a very visual person. I think a lot about the things I see and why they look the way they do. Although most of what we study in the lab are very simple visual experiences, I have an irrepressible tendency to try to explain more complex perceptions in terms of what we've learned from sensory biology. Why are certain architectural spaces capable of eliciting strong responses? What is so special about the October light? Why do some works of art elicit all-consuming illusions of reality? Richard Dawkins called this "unweaving the rainbow" in reference to John Keats's complaint that Isaac Newton had destroyed the beauty of the rainbow by explaining the science behind it. For me, scientific understanding enhances rather than diminishes beauty.
What question would you like to see answered in your lifetime?I'd like to know enough about the brain to be able to fix it when it breaks and to optimize its use for learning, communication and action. To those ends, one of the most important things to understand would be object recognition. How is it that I'm able to recognize something I've seen before? Failure of object recognition effectively strips perceptual experience of meaning and is a devastating hallmark of many psychiatric and age-related brain disorders. There are many elements to the recognition process, but some of the most important questions include: Where and how are memories stored, how are they accessed, and how do they influence the processing of visual information? And there's a related element to the process of object recognition—something we've been studying recently—which is visual imagery. We readily produce pictures in our heads without visual stimulation. Among other things, I have in my head a very det ailed image of Hogwarts Castle, which of course I have never seen. We hypothesize that this imagery is a form of recall—a fabricated construct derived from bits and pieces of things I've seen before and consistent with the properties of the world I know, such as gravity, volume and opacity. We believe that these internal experiences in the "mind's eye" result from memory-driven use of the same brain systems that underlie normal vision. Moreover, we argue that the only way to fully understand perception is to get a sense of how these memory-driven signals interact with signals arising from the retina. This is one of the major goals of research in our lab today, and our findings are beginning to illuminate how features of this imagery system account for dreaming and hallucinations.
How will the Conrad T. Prebys Endowed Chair help?
Generous sources of funding like this that are given without restrictions on their use provide greater freedom to do inventive science. You can stretch the boundaries of current thinking. Unrestricted sources of funding for research enable creative approaches to solving scientific problems, and that's how I plan to use it. Also, in this economy—and I hope it changes before too long—this private funding is a life preserver for basic research, given the difficulty of obtaining funding from traditional public sources.