Michael Merzenich: Brain Plasticity offers Hope for Everyone
“Whatever you struggle with in a sense as it stems from your neurology, the inherent plasticity of the brain gives you a basis for improvement. This is a way underutilized and under-appreciated resource that well all have.” Dr. Michael Merzenich on the Brain Science Podcast #54, 2/13/09.
Recently there has been growing controversy about the effectiveness of computer-based cognitive training programs. As a co-founder of Posit Science, Inc. Dr. Michael Merzenich is a staunch defender of the methods his company uses to validate the programs that they have developed. But for the purposes of this essay, I want to share some of the key ideas we discussed during his recent interview on the Brain Science Podcast.
First of all, I asked him to discuss some of the highlights of his long career. Since he was one of the first neuroscientists to embrace the concepts of neuroplasticity I was curious about how this came about. While he did have some exposure to the animal evidence as a graduate student, it was actually his experience with the invention of the cochlear implant that convinced Dr. Merzenich of the real-world, practical implications of brain plasticity. The quality of the signal provided by a cochlear implant is rather poor compared to that produced in normal hearing, but over a period of months implant recipients are able to progress to the point of being able to discern speech that sounds “almost normal.” This is a practical example of brain plasticity.
You can learn more about this if you listen to the interview, but I mention it here because it provides an important point of continuity between Dr. Merzenich’s early work with monkeys and the work he went on to do with both Scientific Learning, Inc. and Posit Science. Realizing that monkeys’ ability to understand speech was plastic lead to much of Dr. Merzenich’s later work. If you have been to the Posit Science website you know that their first program for older people is based on hearing. While I am sure the debate will continue about the effectiveness of this program, the science is interesting. We tend to be obsessed with memory, and how it seems to be less efficient as we get older. So you might wonder where hearing fits in. Dr. Merzenich’s research indicates that as people get older their ability to comprehend rapid speech goes down. The key idea is that if you can improve hearing comprehension, memory improves. This is because of the well-known fact that richer signals leave stronger memories.
A similar phenomenon has been observed with vision. As people get older they tend to spend more time focused directly in front of themselves and less time sampling their surroundings. Not only does this mean that they literally see less of what is going on around them, it means their memories are impoverished. Thus, Posit Science’s new Insight program is based on training people to regain the habit of frequently scanning the periphery that comes naturally when one is young.
I would hope that in addition to examining these programs for efficacy, more researchers will build on the basic concepts to develop other programs.
While it is important to develop effective programs for cognitive fitness and improvement, Dr. Merzenich and I both think it is equally important that people embrace lifestyles that will utilize the brain plasticity that everyone has. When I asked him for advice he emphasized the importance of physical activity and the importance of “remaining engaged in life.” If you want your brain to stay “sharp” you have to keep challenging it. Avoid the temptation to take the easy way out by intentionally trying things you aren’t already good at. “I am too old to learn …” is no longer a valid excuse!
- Brain Science Podcast #54: show notes to Episode 54 of the Brain Science Podcast with Dr. Michael Merzenich.
- Link to Audio File of Dr. Merzenich’s Interview
Ginger Campbell, MD graduated from the University of Alabama School of Medicine. She also has a Master’s Degree in Biomedical Engineering and spent several years teaching at the University of Alabama in Birmingham. Dr. Campbell has been practicing emergency medicine since 1992. She started the Brain Science Podcast in 2006. Her goal is to help general audiences understand how recent discoveries in neuroscience are unraveling the mysteries of how our brains make us who we are.
Previous posts by Dr. Ginger Campbell, highlighting selected podcasts: