PBS - Scientific American Frontiers:Changing Your Mind:Science Hotline Grafman

Jordan Grafman received his B.A. from Sonoma State University in Rohnert Park, California in 1974 and his Ph.D. in Human Neuropsychology from the University of Wisconsin-Madison in 1981. Dr. Grafman then joined the Vietnam Head Injury Study at Walter Reed Army Medical Center in Washington, D.C. as Neuropsychology chief. In 1986, Dr. Grafman became a senior staff fellow at the National Institute of Neurological Disorders and Stroke at the National Institutes of Health. In 1991, he was named Chief of the Cognitive Neuroscience Section, a position he still holds.

Dr. Grafman also is on the faculty at Johns Hopkins University, holds a number of other adjunct faculty positions at Washington area universities, and is a co-principal investigator with the Defense and Veterans Head Injury Program.

Co-editor of the Handbook of Neuropsychology as well as several other texts on the frontal lobes, head injury, and neuroplasticity, Dr. Grafman is the author of over 200 publications. He is recognized for his work on the functions of the human prefrontal cortex, recovery of function following brain injury, and learning and memory.

For links to this scientist's home page and other related infomation please see our resources page.

Grafman responds :

11.28.00 Roberta McLain asked: I was always under the impression that we really only use 10% of our brain. That much of it was (1) an evolutionary excess, so that in the event that there was significant damage to certain areas, the brain could compensate, (2) that much of the brain is white matter that is available for use later as well. Do we really use the entire brain?
Grafman's response: Every part of the brain is assigned a unique computational function that allows us to do everything from smell to reason about physics. Thus, we use our entire brain. Not every situation or moment requires that we use every single region in the brain but over a few minutes time, you are using every single part of the brain to move, to recognize a familiar face, to comprehend an instruction, to remember a task you were assigned to do, to think about how you can do all your errands after work. To do all this, you need your entire brain. There is room for compensation in the brain. Sometimes a damaged brain area can be healed enough that it can resume some of its prior duties, sometimes the function of a damaged brain area can borrow neurons from an adjacent region in order to process information. But these compensatory mechanisms usually come at a cost. They reduce the capacity of the neighboring or distant brain areas to perform their normal duties. The white matter in the brain serves as cables that connect different brain regions to each other. They allow messages between groups of neurons which leads to a simultaneity of perception or actions that we then perceive as an episode rather than fragments. The white matter is present in the brain but it represents the long axons or "arms" of neurons as they connect to each other.

11.28.00 Elizabeth Flanagan asked: Why do the really smart people have more capacity for storing and retaining information?
Grafman's response: There are some people who seem to have a genetic propensity for being smart. They are unusual. For the rest of us, there is a relationship between curiosity and lifelong learning and the number of neurons in the brain and the density of their connections. This lifelong neuroplasticity associated with learning does allow more information to be stored and is somewhat protective in old age against the ravages of Alzheimer's disease. It really is a two way street. The more intellectually curious you are, the more connections in your brain. The more connections in your brain, the easier it is to store new information.

11.28.00 Mike Polachuk asked: Is it possible that Michelle's remarkable talent for knowing future days of the week was due to the fact that the left half of the brain is the creative side of the brain?
Grafman's response: You are looking for an explanation for the remarkable calender calculating ability of Michelle. Well, that surprised us too! This skill is usually seen in so-called Autistic Savants. It has not been reported in patients who have substantial damage to one side of their brain. It is unclear how Michelle learned this skill. All parts of the brain are assigned functions and we use them all. There has always been an effort to simply capture the quality of what the left side of the brain does in comparison to the right side of the brain. Many people have claimed that the right side is more creative rather than the left side. There is no doubt that basic language skills are stored in the left side of the brain and more nonverbal visuospatial skills are stored in the right side of the brain. Which strategy Michelle uses to get the correct day of the week and which part of her brain she is using is the subject of a study we are currently conducting with her. There are many books that you can find in your bookstore on laterality differences in the brain and the special skills of autistic savants.

11.28.00 Joe Yarsa asked: I took up lessons to learn to play the cello about four years ago. And in that same time it seems that my golf skills have deteriorated. It could just be that I'm a lousy golfer (and cellist for that matter). But could it also be that the part of my brain that I use for playing golf is being crowded out by the part that is learning the new music skills?
Grafman's response: I don't think you have to decide between music and sport! You can do both. Because the brain is a dynamic organ, we are able to have rapid plastic shifts between skills-even if on occasion there is some competition. For example, if you had different movements you had to make with your left hand for typing on a key board or forming chords and you were alternating between playing music for 5 seconds and then typing an editorial comment for 5 seconds, you might have a problem. But switching between golf and cello should not cause much interference. But it just may be that you playing less golf and more cello and that accounts for the decline in your golf game. Or maybe you started to compare your game to that of Tiger Woods! Not fair.

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