Fitness for Your Brain -- In-Depth Doctor's Interview

Ivanhoe Broadcast News Interview with
Michael Merzenich, Ph.D., Neuroscientist,
Posit Science Corporation, San Francisco, California,
TOPIC: Fitness for Your Brain!

You and your team created the Posit Science Brain Fitness Program, which is a series of exercises to stop and even reverse memory loss. How do these brain exercises work?

Dr. Merzenich: The program trains the brain to improve the accuracy and fidelity of the information that you receive in listening. It accomplishes that, and it represents information to the memory levels of the brain with higher accuracy and strength. You don't lose memory because you lose the ability to remember. You don't regain your memory by practicing remembering. You lose your memory essentially because information represented in the brain becomes more and more degraded as we age. The information is in a noisier form. What we're trying to do is re-establish the translation of information into a sharper, clearer form.

Why do people forget things? I mean, if boil a pot of water, I always forget it's on the stove. Why does that happen?

Dr. Merzenich: When we record information in relation to the event, it's translated into the brain in neurological terms. Your brain records the sounds and visual inputs occurring at that little moment in time. There's a function of precision that you see and hear in neurological terms. As activities in the brain become noisier and noisier, they lose clarity. This instability increases as you age.

Why does memory become less stable with age?

Dr. Merzenich: Memory loses stability because your hearing deteriorates. Your vision is slowly deteriorating. It's degrading because your brain is slowly changing, and you have lost neurons or connections in the brain.

Why exactly does memory deteriorate?

Dr. Merzenich: There are two fundamental reasons why your memory deteriorates. The first is that you're not engaged in the sort of fundamental activities that you would need in order to maintain a level of sharpness. Let me give you an analogy. If I learned to play the violin and I achieved a level of mastery, maybe I could become an expert violinist, a professional. This means I would be a master listener and a master at controlling my fingers on the fingering hand. I would be a master at controlling my bow hand. What if I stopped practicing? In a few months, I'd probably be in danger of losing my position in the orchestra. If I didn't practice for 10 years, I'd be a pretty good player, but I'd no longer be playing on the professional level. What does the practice do? Practicing maintains the processing capacity to a very high level. By practicing, we're sustaining the ability of the brain to operate with precision in fast time. We maintain the performance levels through the brain.

At some point, beyond the proof of life, we are no longer learning. We are no longer aggressively defining and keeping performance skills at a high level. And gradually, you accept the loss of performance. What happens in the brain is that the brain that it's trying to hear or trying to see. But the information is represented in a less and less clear way. This is because it's not clear, so it takes the brain longer to make accurate decisions about what it does hear or does see. Therefore, the processes in the brain slow down.

The second thing that happens is that all of the brain operations become slower and slower. You'll see this initially in the form of your movements, and then in all of your operations. All of this occurs partly because of natural slow loss that comes with any aging process. But some loss comes from the fact that you're not doing things in terms of exercises required to maintain high performance ability.

How much improvement can one expect to see from mental exercise?

Dr. Merzenich: Everybody does not improve at an identical extent. Many people who do fitness exercises basically improve anywhere from a decade to two decades or more. If you're 85 and have a normal memory capacity of an 85-year-old, on average, after training, your memory will be near a 75-year-old level. And many people improve much more than that. Of course, on the other side of the equation, many people improve much less in this measure. Almost everyone benefits, though, by recorded improvements in their mood, their engagement, their attention control, and other quality of life measures.

Do the exercises actually change the chemical reference in the brain?

Dr. Merzenich: We have not directly measured that, so we can't say that with scientific certainty. It was designed to. As you age, you don't engage the learning machinery of the brain on a very significant daily schedule in the average daily older life. The part of the brain that controls learning and memory is under-expressed in older brains, so there is less of the critical chemicals that control learning and memory. We're trying to reinvigorate that machine by exercising the brain. So, we really are increasing the levels of these transmitters of the brain with improved brain operations and learning and memory, but we haven't been able to confirm that.

Is there anyone the program doesn't help?

Dr. Merzenich: On one level, you could say the answer is no, because anybody that goes through these training exercises improves as a listener and receiver. That's a direct product of their training. You'll see that enrichment in almost everyone that is trained. The brain processes substantially speed up. But the rates are widely varied in older people. A 20-year-old is processing information in the language domains in the range of about 20 or 30 events per second, so they're making accurate distinctions within that period of a syllable in a word. The average 75-year-old is making those distinctions at a rate of about 7 or 8 events per second, so there is a dramatic reduction of the detail with which the brain is sampling those in a conversation. With this training, the average 75-, 85-, 90-year-old is more at the levels of a 30-year-old, but from the point of view of processing this in fast time. So the dimensions of brain processing can have dramatic effects.

How do you know it works?

Dr. Merzenich: We know it works because we apply it in controlled populations against appropriately balanced controlled strategies. We measure these benefits by psychological testing. We also know it works because we've done limited trials in which we've studied the brain, and we can see that it physically changes responses of the brain. So we've witnessed it working by a variety of things that we measure in positive benefit in a population. But there's also a long history of science that relates to these strategies that have demonstrated these capacities for positive change in older brains in general. That's been expressed in many studies that have been done in human and animal models over many decades.

Do people need to maintain these exercises in order to benefit?

Dr. Merzenich: It appears that once a person undergoes training, the value of the training is only for a period of time. We do believe that mental sharpness will ultimately deteriorate again, a person's functionality will be impaired, and it will be important for them to redo training. We see this more like a general fitness program. Not physical fitness, but an exercise of specific abilities needed to maintain your general health and well-being for the rest of your life.

So it's basically a gym for the brain?

Dr. Merzenich: Exactly.

Can the exercises curb cognitive decline indefinitely?

Dr. Merzenich: What we know is that we've trained a substantial number of people now that are clearly in trouble -- people that are clearly near the bottom of the loop from the standpoint of mental fitness. Many, many people have come up into the normal, more normal status, even above normal status, in a relatively normal period of time. Now, what we don't know is whether this will delay an ultimate collapse. We believe it will.

Is this a process that could work with Alzheimer's patients?

Dr. Merzenich: We are looking at this experimentally, and we are running a trial with scientists at the University of California with a specific objective of determining how far we can go into this severely impaired population and have a positive impact. It's really too early to say, with scientific certainty, who in that population we can help.

What kinds of things can people do to actively preserve mental acuity?

Dr. Merzenich: People must continue to learn in their lives. They must be active learners. This can be achieved in a variety of ways. One major problem is that everyone understands that they need to be active, but they think that being active means that they get up every day.

How can people stay mentally active?

Dr. Merzenich: People can be active learners by learning in new forms and in new domains. It's not just being active and getting up every day. The brain is a learning machine, and it needs to be engaged in new learning of different dimensions. The best kinds of exercise are those that challenge. For example, to master a musical instrument at an older age is a wonderful thing. Or, seriously undertaking the mastery of a second language is a wonderful thing to do. One of the problems with such exercises is that it's very hard to maintain the skills and abilities necessary to maintain a mental fitness program.

That's where we think our program has to come in, because we can be efficient and cover the landscape much more completely than self-directed exercise. It's the value you can get in maintaining fitness at a gym rather than very regimented and directed programs. With the programs, you're on your own, maintaining good fitness. We're trying to extend that fitness.

This article was reported by Ivanhoe.com, who offers Medical Alerts by e-mail every day of the week. To subscribe, go to: http://www.ivanhoe.com/newsalert/.

END OF INTERVIEW

This information is intended for additional research purposes only. It is not to be used as a prescription or advice from Ivanhoe Broadcast News, Inc., or any medical professional interviewed. Ivanhoe Broadcast News, Inc., assumes no responsibility for the depth or accuracy of physician statements. Procedures or medicines apply to different people and medical factors in different ways; always consult your physician on medical matters.

If you would like more information, please contact:

Peggy Jara
Posit Science Corporation
225 Bush St., 7th Floor
San Francisco, CA 94104
(866) 599-6463
http://www.positscience.com