Bernard Brucker is the Director of the Bio-feedback Laboratory at the University of Miami School of Medicine. He has been working in the field of bio-feedback for quite some time. He started his work in 1969 as an assistant research scientist at NYU Medical Center. There he began research on the structure of the brain and spinal cord and its connection to learning techniques that could be used to control individual responses. His work dealt primarily with people who had damage to the central nervous system (the brain or spinal cord). In 1981, he moved the laboratory to the Miami School of Medicine where his work focuses on developing and implementing new behavioral techniques and advancing technology for the purpose of restoring function to people who have paralysis and central nervous system damage to the brain or spinal cord: people who have had strokes, children with cerebral palsy, head injuries, etc. We had an opportunity to speak with Dr. B about his research.
Chet Cooper: How does your work in bio-feedback relate to disabilities?
Dr. Bernard Brucker: The work itself first measures electro-myographic (EMG) responses at muscle sites for people with nervous system damage that would interfere with voluntary EMG signals that occur at the muscle site. They reflect a voluntary signal that gets initiated from the motor cells in the brain, then is transmitted to the brain stem and finally received at the muscle site. Through the years, we have been able to develop some very sophisticated equipment that continues to capitalize on the advances of microprocessor technology. We can detect the smallest signals that may be coming from the brain to the spinal cord to the muscle. The advantage of this is it allows us to see voluntary muscle signals even in muscles that have no noticeable function. One of the things that is well understood is that the cell of the brain and spinal cord are permanent. They are formed and the body is built around it. They are designed to last. The cells in your skin and blood cells are designed to be replaced as you lose them but not the cells in your brain and spinal cord. If you think about it, because these cells are capable of learning, it really doesn’t make too much sense to keep replacing them. You would lose what you had stored in these cells as you got new and younger replacements. We probably wouldn’t be very functional as a species. In many respects, when we learn something, we would like to keep it forever, like learning how to coordinate our muscles so that we can walk and ride a bike. We count on the permanency of these cells. When something comes along and destroys them, like any other cells in the body, there is just a space remaining where these dead cells used to be and there isn’t any mechanism to replace them. This is why the disabilities that are remaining after there is some damage are often considered to be permanent. Normally people can get some spontaneous recovery for the first six months to a year. The field of rehabilitation is geared that way, getting intensive rehabilitation up front, then, as you reach a plateau in their recovery function, it is assumed that you couldn’t possibly recover later. Our whole system has been geared to do this. A collection of published data shows that people tend not to get better in the long term with central nervous system damage. Actually, this information is coming back to haunt us now because insurance companies will not pay for long term therapy, nor will they pay for re-hospitalization later because they can point to extensive literature stating that people don’t get long term recovery. However, long term recovery can occur because some cells in the brain and spinal cord can be traumatized and bounce back quickly or repair themselves to some may not have been damaged. Perhaps people can be taught to use these cells. These are plasticity theories of the brain and spinal cord. Most people believe in the plasticity theory of the brain, but not too many believe in the plasticity of the spinal cord. A lot of traditional work in rehabilitation focuses on getting people more function, knowing that there is damage in the brain and spinal cord. Certainly, people do get more function, possibly because they are learning to use other cells. When we are born, we don’t use our brain cells and spinal cord cells in a very efficient manner. We don’t know how to stand and walk, we learn to do that through a process of trial and error learning. Once the return of function plateaus, the clinical experience described by most people in the field is that people don’t have a good long-term prognosis past that point. Consequently, the professionals in the field are telling people that they need to get used to not having certain functions and to learn to live with it. This has been a big issue, taking away peoples hopes for rehabilitation. But, our work has a different approach than whether or not the muscle is functioning. We actually measure the EMG response. This process is much more precise than just touching a muscle and seeing if someone gets a voluntary response. The field of rehabilitation has always assumed that if there was a neuro-response then you would see it in the muscle. The neuro response and the electrical signal sent through the spinal cord to the muscle was considered to be synonymous. But, when we come in and measure the electrical signal we often see that we can get a signal in the muscle long after there is damage to the brain or spinal cord. This signal often goes undetected. Also the muscle strength does not match the signal because the muscles have become atrophied. While some muscle signals return, many go unnoticed.
The other thing is that we are able to use some very sophisticated techniques of learning and use them at a threshold way lower than at a level of detection. We can measure the signal that you would not possibly be able to see by looking at a finger movement. We can measure this accurately, then display it on a monitor. So when the person is trying to move a particular muscle such as opening and closing the fingers, we don’t measure the finger’s movement, but the actual signal that comes from the brain to the fingers. Very often we can see that there is some neurological signal to a muscle that would normally go undetected. Then we can use these operant conditioning techniques to teach a person to become more efficient at using any remaining or repaired cells in the brain or spinal cord. The way it works is that they are watching their actual motor responses on this monitor. If they are able to access a few more cells, they will see it immediately on the screen because the surface electrodes on the muscle are picking up these impulses. The person can tell if they are doing the right thing or the wrong thing in terms of accessing neurons in the spinal cord even at such small levels. Now by seeing that the person begins to do more of the right thing to get the signal to the muscle, they drop out the wrong thing. Over time we are able to get significant increases to some muscle groups in appropriate combinations to get function there provided that the neuro structure remains. Surprisingly, we see that there are surviving motor neuron units and repairing units long term, that have gone undetected under traditional methods. Bio feedback work is not taking the place of physical and occupation al therapy, it is actually filling in a piece that is missing. We are working at a more primary level, in the sense of using the learning techniques, to have the person become more efficient using brain and spinal cord cells. Muscle groups that had previously plateaued will be able to respond to these methods as well. In a sense, it gives physical and occupational therapy more techniques to work with.
CC: Are you familiar with Ron Gordon’s work on the game he has developed called “MindDrive”?
Dr. B: I am not.
CC: He was the past president of Atari. For the past seven years his new company has been in R&D and has produced the first computer game that is controlled by thought. One game, for example, is a skier racing down a mountain. With your fin ger in a sensor you can cause the skier to move around the slalom course. They are doing a lot of research with persons with disabilities.
Dr. B: This is a similar idea but more specific. What we are interested in doing is having specific motor neuron circuits that control muscles.
CC: They are looking at word analysis where they have certain words that trigger certain reactions. A person with a severe disability may be able to go into a smart house, that is, a computer-controlled home, where with a thought, you could turn on the lights, or open the garage door, even control your electric wheelchair.
Dr. B: The original work of bio-feedback dates back to the 1940‘s and then it was called the learned control of physiological responses. There are two types of learning: one is called operant learning. which most people know as trial and error. The second is called classical conditioning, which is establishing an automatic reflex response. The work with operant conditioning shows that you can actually teach parts of the animal or human physiology to respond to stimuli that it wouldn’t have responded to otherwise, by pairing. Operant conditioning has shown us that if you can identify a behavior within the organism’s repertoire, then you can reinforce it and increase its probability of occurrence. What you have just described, the work with computers, falls into this operant behavior. It is referred to as motor memory or the establishment of the correct motor neuron response from the brain through the spinal cord to the muscles. Once something is committed to motor memory, you have that information forever, unless there is damage to the brain cells. Learning how to ride a bike is one example. Ten years later, you may ask yourself-Can I still ride a bike? But you cannot answer that question because your verbal cognitive parts of the brain do not speak to the motor parts. You have to get on the bike to find out. And, as long as you haven’t damaged that part of your brain, you will be able to ride the bike. This type of learning we try to make as precise as possible.
CC: Does most of your work become part of the permanent motor memory?
Dr. B: This is why when we see people we work with. them for a very short period of time. Since our work is data based we can see how much motor neuron control we have established to a particular muscle. Once it has been established it is in that particular motor memory so people can leave and be able to use the muscle in therapy to make them stronger in terms of walking.
CC: Have you done any work with Parkinson’s Disease?
Dr. B: We have done some work with Parkinson’s patients. but the problems there are a little different. As brain cells get older and because they are permanent, they don’t do some of the functions as well as they used to, One of the very important tasks of the cells of the brain is to manage the chemicals that allow the cells to communicate with one another. These chemicals are called neuro-transmitters. They have to be in the right combination in order for proper communication to take place. One of the functions of the brain cells is to act as a thermostat to make sure that just the right amount of neuro transmitters are present in the synapsis. If they are getting too little, they open the gates and let out more. If they get too much it shuts off. In people with Parkinson’s dis ease, this thermostat system is not working too well and the patients end up not having enough neuro-transmitters. This is very different from specific cells that are not functioning where we can use the bio feedback work. We have not yet developed a method to teach the brain cells to be smarter. But we are doing a better job at regulating the dopamine levels within the brain itself which is one of the problems with Parkinson’s dis ease.
CC: Has there been any work with a monitor using the amount of dopamine in synapses as an indicator on the screen, and then charting effect?
De B: To do a bio-feedback application specifically to improve the functional loss as we see in Parkinson’s patients. we want to work on the cause of the problems not just on the EMG signals. If you could actually monitor the dopamine levels and present them on the screen and the person could see and say what is happening when they are higher or lower, would it be possible for the person to learn that precise control? We don’t have the answer to that because the work you are describing has never been done. Theoretically it may be possible to gain this kind of control. They would be able to see when there were slight changes in the neuro-transmitters and they would be able to produce responses that would bring dopamine into proper alignment. The only reason this is not practical at the present time is that there isn’t a way of measuring on-line dopamine levels at the synapses in a noninvasive way that can be used as a model. If you could do that it would be the way to use a bio-feedback application with the best chance of success.
CC: Do you know of Dr. Truong and the research he is doing at University of California, Irvine?
Dr. B: No I’m not.
CC: Maybe he is aware of ways to monitor the real time levels of dopamine in the brain. Combining the different technologies and research may lead to new findings. It would be interesting to see.
Dr. B: This is an excellent point and this is how a lot of these things come together. I don’t know about on-line measures of dopamine levels. That’s not my real area of expertise. But that is why we turn to other professionals. Through a combination of other areas of research we are able to make advances that make a very powerful application when the fields come together.
CC: How important is the time between a person experiencing a disability and your work?
Dr. B: For our work specifically, the length of time of the damage to the system is irrelevant to this work. If you think about it what we are trying to do has nothing to do with the cells that have been destroyed. We are looking at the ones that have not been destroyed, so we can take anybody and teach them to have finer motor neuron controls to muscles, whether they have a disability or not. Then you could ask us how long has it been since you have had the disability, and the answer is-What disability? You don’t have to have a disability to learn control of specific neurological responses. The time of the disability is irrelevant. We are going to work with the motor neurons that have not been destroyed, but that people cannot use efficiently. This type of work that we do has been used with world class athletes to increase peak performance. This has been very successful. It doesn’t increase strength, but the increase of peak performance is about coordination and the use of muscle at the right time. Someone that has damage may be given neuro motor function that they may not have had otherwise.
CC: Are you involved with athletes and Zen?
Dr. B: This work and the work with Zen were often linked back in the 1960’s.
CC: Is the athlete at the world class level using Zen, concept of visualization and thinking it through, a form of bio-feedback?
Dr. B: There is a lot of work with mental rehearsal. When they are not going through the task physically, they go through the task mentally. But this is not bio-feedback because there is no feedback component here. In order for it to be true feedback there has to be an attempt at the task for which you have an immediate feedback as to whether this attempt has been successful. In some of our cases we have had some very interesting and dramatic findings. We have seen people with tremendous amounts of surviving motor neurons or repaired ones that have gone unnoticed, that have made unbelievable gains many years after initial damage to the brain or spinal cord. They are able to gain good upper extremity function and even become lower limb independent ambulators. This does not mean that everyone can make this transformation. However we can increase the level of function by using specific learning techniques to teach the undamaged brain cells with biofeedback techniques. Most of the time we can bring people to another level of function.