In this episode, I talk with neuroscientist Dr. Michael Merzenich, whose research was instrumental in overturning the fixed brain dogma, replacing it with our present understanding of the brain as dynamic and plastic throughout our lives.

He has published more than 150 articles in leading peer-reviewed journals, including Science, and received numerous awards and prizes (including the Russ Prize, Ipsen Prize, Zülch Prize, Thomas Alva Edison Patent Award and Purkinje Medal). He has been granted nearly 100 patents, and he and his work have been highlighted in hundreds of books about the brain, learning, rehabilitation, and plasticity. In 2016, Dr. Merzenich was awarded one of the world’s top neuroscience prizes, the Kavli Prize, for his achievements in the field of brain plasticity.

He was the scientific consultant and provided the brain assessments and brain training exercises for the Discovery Channel show “Hack My Brain” (which aired in Australia as “Redesign My Brain.”) His work has also been featured on four PBS specials: “The Brain Fitness Program,” “Brain Fitness 2: Sight and Sound,” “The New Science of Learning,” and “Brain Fitness Frontiers.”

Dr. Merzenich earned his bachelor’s degree at the University of Portland and his PhD at Johns Hopkins. He completed a post-doctoral fellowship at the University of Wisconsin in Madison before becoming a professor at the University of California, San Francisco. In 2007, he retired from his long career at UCSF as Francis A. Sooy Professor and Co-Director of the Keck Center for Integrative Neuroscience. He was elected to the National Academy of Sciences in 1999 and the Institute of Medicine in 2008.

In the late 1980s, Dr. Merzenich was on the team that invented the cochlear implant, now distributed by market leader Advanced Bionics. In 1996, Dr. Merzenich was the founding CEO of Scientific Learning Corporation (Nasdaq: SCIL), which markets and distributes software that applies principles of brain plasticity to assist children with language learning and reading.


Soft Wired: How The New Science of Plasticity Can Change Your Life” by Dr. Michael Merzenich

Villers-Sidani, Etienne de, Loai Alzghoul, Xiaoming Zhou, Kimberly L. Simpson, Rick C. S. Lin, and Michael M. Merzenich. 2010. “Recovery of Functional and Structural Age-Related Changes in the Rat Primary Auditory Cortex with Operant Training.” Proceedings of the National Academy of Sciences of the United States of America 107 (31): 13900–905.

Related Models
Model #1: Hardware & Software
Model #9: Plasticity

Episode Transcript

Josh Turknett: Hi, I’m Dr. Josh Turknett. Founder of Brainjo and the Brainjo Center for Neurology and Cognitive Enhancement. And this is the intelligence unshackled podcast. Join me as we take a tour through the human brain to explore and understand the true nature and scope of human intelligence and to unlock the secrets of optimizing brain health and function. In the last episode which reviewed the mental model plasticity, I talked about how for much of the 20th century, the prevailing dogma in neuroscience was that the brain was fixed, incapable of structural changes after childhood development.

And that dogma was challenged in the latter part of the 20th century be research that clearly demonstrated it to be false, research showing that the brain was, indeed, capable of measure, experience driven structural alterations throughout our lives. A phenomenon now widely referred to as neuroplasticity or just plasticity. And while this idea of a changeable brain is no longer controversial, I think that leftovers from this fixed brain era still significantly influence how we think about the limits and the scope of human intelligence and that influence still remains one of our primary metaphorical shackles. We’ve barely begun to understand the scope of what’s possible when it comes to this capacity of the brain to change itself and how to best leverage it and there’s still so much to be gained from doing so.

A major figure in conducting the research that led to overturning the fixed brain dogma is my guest on today’s podcast, Dr. Micheal Merzenich. Not only has he dedicated his career to conducting this important research but he’s also made an effort to spread it well beyond the world of academia, realizing just how important it is not only for realizing human potential but also for maintaining the health of the brain and in preventing cognitive decline and dementia. And you’ll hear of some pretty remarkable research along those lines that he was part of. He has had a long and prolific career in the neurosciences publishing more than 150 articles and leading peer review journals including Science and Nature and received numerous rewards and prizes. He’s also been granted nearly 100 patents. His work has been featured on several PBS specials and he was also part of the team that invented the cochlear implant which was a real breakthrough for those with hearing impairment.

Also at the conclusion of the interview, I will return with a few of my key takeaways from it. So, without further ado, here is my interview with Dr. Micheal Merzenich.
Okay, so I am honored to have with me on the podcast today Dr. Micheal Merzenich. Hello, Dr. Merzenich.

Micheal M.: It’s nice to be with you, Josh.

Josh Turknett: All right. So, Dr. Merzenich has had a long and prolific career in the neurosciences. He is, I believe, a professor emeritus at UCSF and a member of the National Academy of Scientists in the Institute of Medicine and accomplished a lot of the seminal research in the area of neuroplasticity, the brain’s ability to reorganize itself in response to experience which is, essentially, a biological foundation of all learning. So, it’s of immense importance to the aims of this podcast or to the understanding of how we can realize the full potential of the brain. And his work has not only been broadly influential in ways that we’ll discuss but it’s also significantly impacted my own trajectory. So, I first learned about his work as an undergraduate pursuing a degree in neuroscience.

And so as an undergrad neuroscience major in the late ’90s, I wrote a paper and a presentation about Dr. Merzenich’s research and that turned out to be a pretty formative moment in my own life and career. Up until that point, I had held a personal conviction that our success in learning anything whether it was academics, sports, art, music, that our success was governed far more by the process in which we went about learning rather than any innate talent or predispositions and in my own personal experience, my success in learning anything seemed far more a product of the quantity and quality of practice or how I went about learning than anything else.

And yes, that seemed to still be a minority view point and the idea that there were innate talents and aptitudes was still the pervasive view point, especially in certain domains. And I think that that was, in part, a direct outcropping of the notion of the brain as being essentially fixed in form in function after early childhood development. Which up until to the mid to late 20th century was still the prevailing dogma. And so, for me, when I first discovered Dr. Merzenich’s work on plasticity it felt like here was the scientific foundation for what I’d felt was true experientially.

And here was scientific evidence that overturned that dogma and yet it still hadn’t seemed to make its way into impacting broader society and not only was the research crucial to providing the scientific and biological basis for those concepts but it was also of immense practical use and that understanding the mechanisms of plasticity could be especially useful in forming our own learning process and in better leveraging the brain’s tremendous capacity for adaptation and growth.

So, I began applying and refining those concepts personally and began sharing them with other and ultimately formalized that into the Brainjo method for learning how to play music and reflecting back on it I can see where the seeds for a lot of that were sewn through those early encounters with Dr. Merzenich’s research on plasticity. So, you’ve clearly carved out a unique career for an academic scientist including, essentially, helping to create an entirely new field within the neurosciences. And I’m especially interested in the paradigm shift that you helped to usher in years ago from seeing the brain as fixed to seeing it as plastic. And so, maybe you can first take us back to how you got into the field of neuroscience and plasticity research in particular.

Micheal M.: Well I was interested in neuroscience, josh, because I was interested in our humanity and I thought that I’d like to study the nature of our humanity and initially my notion was to pursue it in philosophy to become an academic philosopher or maybe a psychologist. In thinking about it, I thought well, the real answer probably lies in the wet tissues of the brain and understanding the brain as it accounts for the evolution of our personhood or the nature of our personhood was probably where the real answers were and so that led me to study neuroscience. And as a neuroscientist, my whole quest, you could say was to study the brain as a learning machine and learning organism. I wanted to understand why we do what we do, how we acquire our abilities in life.

And, of course, as you say that a notion when I was a young scientist, a young student, was that the brain was fixed like the computer on your desk and there were algorithms in it that were operating and it had to be pretty amazing and you could struggle to understand how all of the wonderful things and abilities, skills, information storage occurs in a life, in this fixed machine. And then I did experiments across the early phase of my research career that demonstrated in a very clear way that this could not possibly be right and then did experiments that directly challenged the idea that the brain was fixed in an older aged animal and in an older aged human.

One of the things that changed my thinking about it was work that my research group conducted in the development of what became one of the commercial cochlear implants. And this is a little bit off subject, Josh, but my research team basically led to … created one of the first operational cochlear implants which is one of the commercial cochlear implants that’s out there in the world today, it’s been applied in hundreds of thousands of deaf individuals. And as we applied these devices, what we were trying to with them was to simulate the patterns of input from a dead ear that would normally be delivered from a healthy intact ear and we did that by shocking the acoustic nerve and we could only do that crudely.

There’s just practical, mechanical, and physical limitations to how well we could achieve that, I liken it to playing Chopin with your forearms or your feet. And it’s also exciting, the region of the inner ear which normally represents only the squeakiest of sounds, not sounds of [inaudible 00:09:17]. So, not surprisingly we plugged this into an individual that’s been deaf for a while and initially they’d say that what they sound … what they hear is trashy. It sounds like somebody playing the accordion, I’ve never understand those, right? It sounds like a robot, right?

Three or four or five or six months later, they understand everything. And they say, “Oh, it sounds just like it sounded before I lost my hearing.” And so, I thought, “Is this a miracle of our engineering? Is it really happening?” And it dawned on me that the brain must be making adjustments on a massive level, they must be connectional and physical. And about the same time I was doing studies in the basic organization of the auditory brain and I realized that what I saw in the organization of the brain, I say what I saw, what we saw just did not match the notion that we construct reality as by in a fixed machine that has fixed connections. It just didn’t make any sense if that’s what the brain was organized to do.

Then we did experiments in which we modified the inputs to the brain that were done from the somatosensory surfaces of the body, from the feeling surface of the body in an animal model. And we saw the brain in an adult quickly, and on a very large scale, reorganized itself. And that led to experiments in which we demonstrated that in an animal of any age, you can train the animal and with the acquisition of the new ability or the improvement of any ability, you could track changes in the brain that accounted for the acquisition, whether it accounted for the improvement. The acquisition of any ability to improve of any ability is brain remodeling. And it’s remodeling on a fundamental sense in the connections of the brain that accounts for its operations but it also is remodeling in the operational characteristics of the machinery of the brain.

The brain, initially, is only operating very sloppily and noisily and not very precisely. And now I train the brain and now it’s operating with high precision and high accuracy, at high speed. And so to see the basic operational characteristics of the brain change as you engage it in training was exciting to us. And that led us to try to say, “Well, what rules are operating to control this change and produce [inaudible 00:11:59] on the first level, we knew what those rules were. And at that point we could change the brain, in a sense, at will within the limits of those rules. So, I went through this personal revolution in my thinking about it over a period of about maybe 15 years, Josh, it may not sound like it [crosstalk 00:12:20]. But, to realize that the brain is a continuous work in progress, that it’s created us in all of our operational abilities that define us operationally, it’s actually created the person that we are.

In a sense, Josh, it answered the great question that I set out as a neuroscientist to answer and that is our true natures as we account for our abilities that define us as we account for the creation of ourselves in our operational … in defined in operational terms. So, anyway, from that point forward I’ve been trying to understand how to deliver this science out to help people, regular people in need of help.

Josh Turknett: Right. So, since you mentioned going, initially thinking you were going to take the philosophical route and then going into the neurosciences, did your observations of the brain in terms of its plastic potential and this realization that it was always in flux, did that challenge any kind of existential notions about the self, for who you were at the time, did that filter into your own personal philosophy?

Micheal M.: Well, I began to realize that the self is a creation of plastic processes in a brain. And because people conducted really important experiments, not … the initial experiments were conducted by Japanese scientist in the 1990s who demonstrated that the brain is operating to connect things that are associated, physically associated, the association of information by which we construct our realities, you could say, is a physical process. I think it’s one of the great discoveries of modern neuroscience and worthy of a Nobel Prize but it’s one of those things, great discoveries [crosstalk 00:14:27] over because people don’t appreciate the extended significance of it.

We construct reality by how we associate things that represent the nature of the things as a whole basis of our understanding of the world we live in and every time we feel, every time we think, every time we act, we make a second association. And that association is to the source of the feeling or the action of the sensation of the thought. And that association is to … and that is where the source is us. We are massively, physically self-referenced and we create this entity, you could call it we’re creating a captain of our little ship. And as it grows in its power, it grows in the construction of this entity, it actually creates … it actually engenders agency, it becomes an agent, it becomes a controlling force in our brain. This is created through our plastic process in our brain in our lifetimes, in our early lifetimes obviously. And we have a commander in our ship that’s been self-created you could say by these plasticity processes.

And it’s subject to our improvement on our strengthening and our modification at any time in our lives. And I wish everyone out there, Josh, everyone who’s listening to this to understand that they are a work in progress. That everything that’s important to them can be stronger, still, in operational terms in their brain. That they’re capable of transforming themselves and carrying themselves to a higher level in everything that matters to them.

Josh Turknett: Absolutely. I couldn’t agree more. And it seems like on the flip side, the other point of view where we’re fixed and we can’t change things arose from maybe both the ideas of the brain as being fixed that were held for so long and also the discovery of genes and DNA and the belief that that DNA was our fate and we certainly know that both of those things are not true to any degree. So, your research with the cochlear implants and with the somatosensory reorganization, what years are we talking about there where that was going on?

Micheal M.: Well, the cochlear implant development occurred primarily across the 1970s and 1980s [crosstalk 00:17:04] operational, it was commercialized in the 1980s. So, from that time to this, there have been … we’re not so far away from a millionth patient in cochlear implant [crosstalk 00:17:16] hearing. And then we initiated the research, definitive research, in plasticity you could say in about the mid-1980s and by the mid-1990s we had a pretty clear idea of the operational rules that defined brain change on a first level. I mean, as you know Josh, neuroscience is a complicated business if you get down to the details of it.

But, the other thing we didn’t initially fully appreciate, Josh, is that a lot more is changing beyond connectivity. And actually several physiological psychologists began doing experiments in which they looked, for example, at the impact of training on the vascularization of the brain or the supply of nutrients to the brain or other things like this. And we, ultimately elaborated those experiments, we made long list of things that in which we ask ourselves, “Are these altered when we engage the brain intensively in learning?” And we saw that the brain is actually changing in its physical characteristics in every dimension. You can train a healthy brain. You can say is supplying plenty of nutrients, oxygen, so forth.

It’s got a strong and competent set of immune processes. It has a highly developed blood-brain barrier that has high integrity and so on and so forth. Whole series of physical changes occur when you engage the brain in a healthy way in exercise. And so it’s really important that you think about exercising your brain, you think about brain health. The traditional view is that if you have a brain and you’re under control, it’s healthy. But, of course, that’s silly. There are variations in its organic health. And just as if you could look at 100 people and say, “These people are very physically healthy and those people are obviously not.” This certainly applies for the organ inside people’s skulls.

And one of the things that drives me crazy, Josh, is that there has not really been developed a brain medicine. There’s not a routine brain exam when you go to the doctor. And to just assume that everything is fine.

I think part of it speaks to the resilience of our brains is even when it’s not operating optimally, it still does pretty well. And maybe that gives the illusion that it’s doing better than it it. And you were talking about some of the changes that occur just beyond connectivity with learning and obviously you’re familiar with the research showing that engaging in learning seems to have neuroprotective benefits and there are speculations as to where that could all come from. One idea is that it’s just increasing the cognitive reserve so if you have … your brain can do more so it’s more resilient to degradation if you have some degree of redundancy built in.

But, it seems to be that there’s more than likely other things going on which you eluded to there where you’re not only improving the software components of the brain but you’re also improving its hardware through new learning. Would you agree with that as part of the … at least speculate in terms of the benefits of learning as it pertains to brain health and protecting against neuro degeneration?

Micheal M.: We’ve done direct experiments that relate to this. So, for example, Josh, one simple experiment that we’ve done is we made a long list of things about the physical and functional brain and the list encompasses about 30 different physical, functional, chemical characteristics you could say. And then we’ve just contrasted the state of the brain in an animal near the end of life to an animal in the prime of life. And the first question you can ask is, “Well, how many of these 30 different …” I’ll say a little bit about what these things are in a minute, “How many of these 30 things are different in an animal near the end of life versus an animal in the prime of life?”

I might say we’ve also done these experiments in a second way. We’ve given an animal a terrible, challenging, early life. And then we contrast with an animal that’s had a normal, healthy, early life. And everything is different in the animal that’s struggling. Everything’s different. So, when you’re close to the end of life, everything you look at is different from the same measures in the prime of life. How many of those things advantage the older brain? And the answer is none of them.

The younger brain is faster, it’s more competent, it’s more reliable, it’s more organized, the responses are of greater magnitude, the inhibitory power is greater, everything you look at is stronger in the young brain versus the old brain. Advantage is the young brain in its operations. And then you can ask, “Well, how many of those things can be positively reversed by training the animal?” And the answer is all of them. Everything is reversible. And in an animal model, we did the initial experiments in rats. We’ve subsequently done many of these parallel experiments in humans but initially we studied this in the rat model. In the rat model, virtually, you can have an animal that’s expected to die in a month or two and you can train the animal intensely.

Well, the brain looks like the animal at the end of that training in an animal that’s in the prime of life by virtually every measure. Now, what were some of the measures we looked at? We looked at myelination. We looked at the spreads of processes of neurons. We looked at the activity of inhibitory neurons. We looked at aspects of processing speed, of operational speed, we looked at the organization of brain systems. We looked at a whole pile of things related to the vascularization of the brain, the oxygen and resources in brain tissues, a whole bunch of elemental things that relate to, you could say, the integrity of the brain as it relates to its health. We looked at the blood-brain barrier. Many different dimensions of the physical and functional brain. All of them are rejuvenated by appropriate forms of training.

Now, what are the appropriate forms? What we did is drive the brain, the magical processes, drove the brain to operate with improving accuracy at speed at every brain level and by at every brain level, I mean the brain is operating accurately at speed and resolving what information is arriving, you could say on the front doorstep of the Brian, and it’s also operating at the accuracy and speed it’s making judgements about what it’s just seen or heard. It’s manipulating information in training in relatively simple ways. Now, when you drive the brain accurately at speed, you’re driving the processes of the brain, you could say to, and the machinery of the brain, to a highly resolving state.

And fundamentally, we’ve known for a long time … and this is, Josh, this is cognitive reserve. You could say that a brain that’s operating accurately at speed is a brain that has lots of cognitive reserve. So, another way of putting it is we need … we should be seeing how effectively how brain is operating at speed all across life. And if you’re slipping in these abilities of having your machinery, you could say, and operating in that tip top performance condition, you should do something about it.

Josh Turknett: And then, so how would you translate those ideas and that research into a practical guidance for those who are trying to restore a more youthful brain?

Micheal M.: Well, first of all, self assess where you are. You can do that, you know operationally, whether or not you have really “slowed down.” And it’s a relatively easy thing to measure. At our website Brain HQ, it’s relatively easy to self evaluate your processing speed. It’s how you sit in terms of the rest of the human race or other people of your age. And if your processing speed is not up to speed, then you should do something about it. There are lots of things you can do about it. I love your music training [crosstalk 00:27:20], as an example of something that really would challenge you to operate with accuracy and speed. In fact, if you look at the average musician, music is very, very healthy for you especially music performance.

I mean, ping pong. [crosstalk 00:27:39], I don’t really care what you do. But, do things that drive improvement of your operations at speed. There’s lots of fun, interactive games that you can play with other people that basically drive you in your performance at speed and then you can go to a website like our website Brian HQ and exercise our brain on the exercises there. There’s just lots of things that you could do in everyday life that would improve these elemental abilities. And I think they represent an injection of cognitive reserve.

Josh Turknett: And what are your thoughts as to why the average trajectory is for that to not happen in this day and age in terms of it seems to be that the average adult doesn’t continue to engage those mechanisms throughout life and tends to end up in the state of the [inaudible 00:28:42] and the experiments that you talked about? Do you think that’s just an inevitable consequence of the ways our lives are organized or do you think there’s anything more to it than that?

Micheal M.: Well, I think there’s two fundamental reasons. First is ignorance because if you’ve thought about your brain health at all, you were informed at all, you’d know that you should be exercising your brain just like you’re exercising your body. And one of the things that drives me crazy about this, Josh, is that people are told that exercising their body is what their brain needs. And it is important for their brain. But, their brain also needs to be exercised in and of itself [crosstalk 00:29:27]. So, one thing I say is just the public doesn’t understand the importance. They haven’t got it yet. There was an evolution in people understanding that they needed to do things about their physical health and that might lead them to go to the gym and be good soldiers about it. That has not occurred yet with the same fervor for the brain, it should.

The second reason is because we have designed a modern lifestyle so that we can operate effectively without the use of much of a brain. We’ve paved every surface that we step on and by doing that we are depriving ourselves of hundreds of thousands of moments in a year when a footfall would be uncertain. And we’d have to make little neurological adjustments to it. We live a life in which we acquire our abilities that lead us to the occupation that dominates our life and activities that dominate our life and at that point learning for many people is substantially over. Everything is done from memory using largely automatized abilities and we have very stereotyped operations in our brain and in our life.

Stereotypy is poison. We need to be continuously learning, continuously challenged. In the native human state, people didn’t get over their challenges just to survive. They were continuously challenged and had to be continuously adaptive. And then it’s really important that we keep the machinery healthy, that keeps track of where we are in the landscape that we live in. Most people have no real reconstruction in their brain of the landscape that they live in. They look up the way to go anywhere and they don’t really know, they can’t really tell you even the details of what’s on the street that they live on. They’re so disengaged from the physical reality of the world they live in. And all of these things are contributing to their demise. To the degradation of the faculties that would sustain them. It’s not just that we don’t exercise. It’s definitely that we do things deliberately that will carry us into the ditch.

Josh Turknett: Yeah, I’ve thought about as a personal metric, the degree to which I’ve run on autopilot or the percentage of any day I’m on autopilot as a gauge of how well I’ve done in terms of engaging neuroplasticity mechanisms and it would be nice to figure out a good way to operationalize that but I think it’s such an important concept but not only is it a way of framing whether or not you’re learning new things, it’s also a way to slow down time and the more novelty we have in our lives, the slower things go and the more we’re running on autopilot, the faster time goes. So, it’s good for those of us who are interested in prolonging the experience of our lives.

Micheal M.: One of the things that I tell people to do is say, “Imagine, in your mind, reconstruct the details of what’s on the street that you live on. And then okay, go two blocks away in your mind. And then reconstruct in your mind, in detail, what’s on that street. Some block that you’re very familiar with that’s nearby. Then go there and look.” And what the average person will see is are many, many details, in a sense, that they’ve never seen. They didn’t fully appreciate or certainly were unable to reconstruct were there. Even though they’ve seen them thousands of time. And that’s because, in a sense, they’re disengaged.
And in our native human state we weren’t permitted to be disengaged. But now our brain can be operating with us largely offline. And just walk down the street and look at the people that you pass and see how many people are, in a sense, living zombies because it’s a very common modern human characteristic. People are just definitely out there in the world, disengaged from it.

Josh Turknett: Absolutely. We’ve come a long way, I think, in recent years in terms of embracing the idea that at least the brain isn’t fixed and there is capacity for change but I think that there’s still prevailing belief that most of that capacity exists in childhood and then it greatly diminishes during adulthood. And in the book, you talk about the concept of a plasticity switch and that in the early years of development, that switch is always on.

nd I think that’s a really important concept because it could simple be that in childhood that plasticity switch is genetically programmed to be on during development and after that period, perhaps we have to be deliberate and intentional to turn it on but it’s not that it goes away. So, do you think of plasticity itself as a mechanism as being plastic? In other words, is there evidence that continuing to engage the mechanisms of neuroplasticity keeps those mechanisms up regulated or keeps that switch easier to turn it on in a way that optimizes the brain’s ability to change itself?

Micheal M.: Absolutely, Josh. And this is really an important point and the machinery that controls change is plastic. So, basically it’s actually been well studied. When you engage the brain aggressively as a learning machine, you actually strengthen the machinery that controls learning. It’s a self feeding process. The only thing that we’ve done is we’ve taken … we’ve trained hundreds of thousands of people of all ages. And on computer based exercises and one of the things we’ve done is we’ve tracked the changes that occur in an older brain as they initiate our exercises on the computer and initially they’re poorer, they’re slower in acquiring ability than is a younger person.

But, after a period of time, as they exercise the machinery, they’re up regulating the processes that control change. And they catch up. So, at any age, you can actually exercise the machinery in the brain by having a more aggressive life that’s learning filled and acquiring new ability and new talents and that actually improves your capacity of learning in general terms. So, I say get me to the exercising your brain, take up some activities or think about a regular schedule of the acquisition of a new ability or elaborating the abilities and doing the things that you really love, that you’re really into. Don’t rest on your laurels. Engage your brain as a learning machine [inaudible 00:36:41] take it up a notch. And a person that adopts this as a habit basically is strengthening the processes that are controlling learning and memory themselves. You want that machinery to be more powerful. You want it to be more reliably operating with strength and fidelity.

Josh Turknett: It’s almost as if the ease of modern life sends a signal that these mechanisms aren’t needed anymore so why waste energy on keeping them up regulated?

Micheal M.: And ultimately when they die off to either parallel because their progressive loss is directly contributing to your … to the dangers that apply to, ultimately, slipping into the man’s share of Parkinson’s disease or other things you do not want to have happen to you.

Josh Turknett: Absolutely. So, if you don’t mind, let’s go back for a minute to the early research you did which was, I know, quite revolutionary at the time because I’m interested in how paradigm shifts like that happen and just curious to know what the reception was in the scientific community back then and how you think it came to pass that it ultimately was embraced because it has been.

Micheal M.: Right. It’s funny because it was interesting to come up with something that, in its time, was so … must be so astoundingly wrong to so many people. I remember a time as a young scientist, I was presenting some of these early findings in an audience of a very highly distinguished individuals and a Nobel laureate rose from the audience and said, basically, that in a very denigrating way that this could not possibly be true and that it was completely misleading the audience and that I should … and so it’s not that there’s a concern about something like that because you know the scientific information stands on its own.
You know you’ve collected data carefully and you know that you’ve gone through the logic and that no mistake has been made because we knew that what we were doing was contrary to the dominant belief. And we knew that we had to have everything lined up and our arguments had to be complete. But, still, the initial reaction was met with substantial level of hostility. The belief that the brain was fixed like the computer on your desk, hardwired, was so embedded and it was imagined to be a major accomplish in the achievement of brain science and it’s example of how everyone can be … because there was a perfect storm of information that misled people into believing that and to coming to that conclusion that reinforced one another. It was at the same time daunting and exciting to be able to contribute to what we realized from the outside was probably a major correction.

Josh Turknett: You had enough confidence in the science to know that ultimately it went out no matter what people were saying at the time.

Micheal M.: And then what happens over time, Josh, is that people do experiments that affirm it 1,000 and ultimately 100,000 times over. And so it reaches, within a few years, it reaches a point that really fundamental deniability for anyone that really was closely following the science. So, the truth always wins out. And ultimately that happened here of course.

Josh Turknett: Right, just like for that to happen quicker rather than slower.

Micheal M.: Exactly. One of the things that frustrated me about it was that I saw quite early, I saw the practical implications of it for medicine or for health and that’s still the progression of this advancing into medicine to change the way of thinking of medical doctors, neurologists and psychiatrists, all the people that are fundamentally interested in brain health has been so slow. So, I just wish there was some way that I could raise my whip on the [crosstalk 00:41:31]-

Josh Turknett: Yeah, well that’s part of this reason for this line of question is trying to figure out how to get people to embrace certain ideas. We’ve come a ways but there’s a ways to go, I feel, in a lot of different ways and do you have any … are there any particular applications that you see in the field of health?

Micheal M.: Well, I think one of the principle applications relates to how we think about things like the progression to dementia or Alzheimer’s or other dementias. After all, at some point, a person feels on a relatively elemental test, a metric test, they can’t tell you whether it’s a giraffe or a lion or whether they just remembered something that almost anybody could be inspected on. And then at that point they have Alzheimer’s disease. Well, did they have a week ago? How about a year ago or five years ago or 10 years ago? Did they have just a little bit of it and then how about a year later, they have more of it? The notion that you can draw some line of performance across the person’s history and say, “This is the point at which we should be concerned about their health. The health of their brain,” if, of course, nonsense.

I believe that we have it within our power now to actually evolve a practical medicine of the brain. By that I mean, when you go to the doctor there can be simple things that could be measured that would give a gentle index of rain health. For example, it would be very easy in a minute or two, it’s just as easy as taking your blood pressure, to determine whether or not your brain is operating accurately at speed. If it’s not operating accurately at speed, then that would be a first index like taking your blood pressure that all is not well inside. And now that would call for maybe a little deeper look, right? And we have the power. A person can go home on their computer or on a cell phone and then 20 or 30 minutes all kinds of things can be measured. And then that can lead to a more direct physical measurement in the brain. Just like you’d go to a more direct physical measurement of your heart or the state of your vascular system or your lungs.

So, we have it within our power now, Josh, to actually organize a strategy for continuous expansion of the health of your brain. And that should be something that comes into medicine as a regular course in medicine. So, anyway, one of my hopes is that this … is that we evolve to have a more sophisticated approach to this within the medical community and at the same time we evolve the understanding of the average citizen who that they’re doing a lot to make sure that they’re monitoring their own health, the health of their own brain. And basically taking care of it just like they’re looking in the mirror every so often at their body and they’re taking care of it. And I think that it’s within our power to really, radically change the quality of lives on the fiscal average by doing this.

Josh Turknett: Right, I think, too, part of the maybe resistance in the medical community towards doing that early assessment for different metrics is the notion that, “Well, what are you going to do with that information if you can find it?” There’s still this idea of inevitability about it and so obviously you and I would say that’s absolutely not true but still, but on the flip side it’s not only that we have ways of assessing breakdown at a far earlier level than we say it’s clinically manifest as a diseases. But, on the flip side we also have something we can do about it to reverse those changes in both of those messages. We also have something we can do about it to reverse those changes in both of those messages really need to get out there.

Micheal M.: Absolutely and you’re absolutely right. That is the second, great problem is that too many medical doctors have been trained to believe that in the hopelessness and limitations in the fates of people that have these or this or that diagnosis. It’s just so exaggerated. And it’s still a major problem in medical delivery and care. So many people basically suffer from that when there is real hope for them. And yet, that in a sense that’s denied to them by a medical doctor that really doesn’t know themselves what to advise a person to do.

Josh Turknett: Right. In the book, Soft-wired, you have several examples, stories from people that you’ve worked with in terms of some pretty impressive changes in plasticity. And those are, obviously, wonderful examples for people to know about just because it shows the scope of what’s possible. Is there anything or anyone in particular that stands out for you as a good example of that.

Micheal M.: Well, it’s hard to talk about because there’s another report from somebody who’s life has been changed by this that occurs almost weekly if not [crosstalk 00:46:57] weekly. And so, anybody can work intensely and we have people that are terribly brain damaged. I have a friend who was a former peacekeeper in the British army and he became my friend through his wife who basically was … he had a terrible, really a massive stroke, he had a substantial amount of brain removed as a consequence of recovery and the processes of recovery, nevermind how that occurred.

But, so he has a very misshapen head as a consequence. Which is very distracting to some people that see him. He visited me from the London a few weeks ago over a period of about four years, this guy was told, initially, “Why keep him alive? There’s no real point.” He’s amazing. Not that you wouldn’t know that he’s had brain damage but he’s an operational human being that can talk to you and understands what you’re saying. His speech is still a little funny, he still has a little bit of aphagia but by and large he’s with it, he’s happy, he’s having a great life, he was going to visit his daughters in New Zealand and he stopped by to see me.

And there are so many times you see somebody who’s been in some kind of major trouble who basically is restored to a life that’s still very positive and valuable, if not wonderful for them.

Josh Turknett: Yeah, and I recall early on in my neurology training before I entered it, the prevailing ideas in medicine were pretty nihilistic about neurological recovery and even early on seeing some cases, whether it’s stroke or other type of brain injury and the recoveries that would happen, I would see someone in the hospital and see them back in several months or a year later and see these remarkable things that I was totally unprepared for because that prevailing narrative was so strong. And that alone was enough to challenge him and say, “Wait a second. Something’s wrong here, there’s more capacity.”

Micheal M.: This guy would never walk and he would never … all this. And so he’s telling me about how he has about a half an acre around his house and he’s telling me about his, basically competing in the flower … at some local flower show in his community because he’s so into his garden and so into raising flowers, growing flowers and vegetables in his British garden. Come on. This person with a physically lost life and mentally out of it and never going to do anything useful or … I mean, there’s so many stories like that, you’re right. And why should it be surprising to you, the brain is plastic for god’s sake.

Josh Turknett: Right, it’s truly remarkable, some of the things that can happen. And it’s unfortunately still not widely know.

Micheal M.: Well, one of the things that isn’t known a lot of times, Josh, is the intensity it takes. You have to change the brain from some deep hole like this, it’s a lot of effort involved. There’s a lot of intense effort that has to be put in in order to drive the changes that can be corrected like this. And people way underestimate the requirements of rehabilitation commonly when the brain is wounded or when they’re really struggling.

Josh Turknett: Yeah, so much of the major learning that we do in early childhood is all scripted. It’s a major effort to learn to walk and talk but it’s all been programmed in so it happens naturally. So, then you have to deliberately will that process into being [crosstalk 00:51:11] to take advantage of it but it’s still there, that’s the point. It’s not, like you talked about the plasticity switch can still be turned on, we can still get all that stuff but it just requires a more concerted effort to take advantage of it in that scenario. So, before I let you go, can you tell me how you’ve applied your own understanding of the brain’s capacity to change as well as the ways in which it improves the health of the brain to your own life. How have you operationalized it for yourself?

Micheal M.: Well, I describe this to some extent in my book. It’s [crosstalk 00:51:49] an egoistic adventure. But, you could say that I’ve adopted a life of continuous learning, that’s the first thing. I’m a man of a 100 hobbies and so I have a [inaudible 00:52:06] garden and I have fruit trees and I have a vineyard and I have wood workshop and I make a pot. And I’m continually trying to improve my skills and abilities and artistic in the physical sense and as a craftsman and as a gardener and lots of other ways.

But, I just see a life of continuous self improvement. And these things really relate to things that I value, that I enjoy, I have fun and a lot of it relates to trying to figure out how to not just contribute to my own self development. But you can say to the [inaudible 00:52:46] other people around me. It’s about doing this in a social way, it’s about doing this in an interactive way, it’s like doing this with a level of generosity, other people around me, around our family. So, one of the ways we organize all of this activity is with other people. And other people help us make the wine and share in it. Other people help in gathering the fruit and making use of it in some fact or way. Other people help us pick our olives and make the olive oil or pickle the olives. All of these things.

So, I’m just trying to lead a richer personal life that values me and my brain. And that is a positive contributor that you could say to the brains of others. That’s one of my basic goals in life. Of course you’re always trying to continue to add to the richness of the information that you have that comes from understanding of things in the world. I’m trying to be a better person. I’m trying to have a deeper understanding, I’m trying to bring more joy and love into the world. I’m trying to do that with understanding.

Josh Turknett: And of course it’s all grounded in the belief that self improvement can continue as long as you’re alive, that it’s not something that [crosstalk 00:54:08]-

Micheal M.: You have the potential, I think, whoever you are out there, to continue to grow. You have this capacity to change for the better. Why wouldn’t you at least make an attempt to do that? Why go into retreat and wait for the end days? Why not turn things in a positive direction?

Josh Turknett: Absolutely. To me there’s nothing more fun. So, well I want to be respectful of your time so we’ll wrap up here in a second. Is there anything else that you’d like to share or any place you’d like to direct people who are listening to learn more about your and your work?

Micheal M.: Well, you can read my book Soft-wired, that’s a place to start. But, I’d just like to say to your audience that you’ve been given a great gift and it’s just an unbelievable power and it’s the power to change yourself, to change you because your brain is you. And to change you for the better to make yourself stronger and safer and more capable and more confident. And if a person doesn’t take advantage of this gift, they’re just a damn fool. So they should do it. They should consider this a call to action. And Josh, you’ve done a lot of things in this domain to help people exploit this gift. You’re another resource that people can look to as ways to exploit it. And why not look for a better and stronger life?

Josh Turknett: Yeah, and I think, as you probably do, too, that we’ve probably only begun to scratch the surface of what’s possible in this arena and so the more people who are trying to exploit this throughout the lives, the more we’ll learn about just what is possible. Well, it’s been a thrill to get to talk to you today. One thing, I think, worth noting is that you’ve done a great job not only of discovering new and important ideas but in figuring out ways of getting those ideas out of that ivory tower so that they can be of practical benefit in people’s day to day lives.

I think that’s something that needs to happen more and more and so that’s a great example. As I said, your work had a profound impact on the trajectory of my life and I’m sure that’s been true of many, many other people now. So, thank you for taking the time to come on the podcast and thanks also for the body of work that you’ve put out over your lifetime.

Micheal M.: It was really fun to talk with you, Josh, and to meet your audience in this strange way.

Josh Turknett: Okay, well thanks again to Dr. Merzenich for sharing his time here on the podcast, you’ll find links to where you can learn more about him and his research on the show notes for this episode. And if you want to check out his online brain training program which is based on the research he’s done over the years and one of the most rigorously tested tools in the brain training space, head over to So, now I’ll share three of my key take aways from that interview. The first being that I think it’s really important to remember that this is all brand new, that this entire paradigm shift from thinking of the brain as fixed in structure to a dynamic continuously changing entity really just happened.

The body of research that ultimately overturned the fixed brain dogma was compiled in the latter half of the 20th century. And in the grand scheme of things, that’s yesterday. And so, as I mentioned in the last episode, we still have no idea what the boundaries are when it comes to our brain’s potential for change and have barely explored the way we can leverage it. So, I think it’s critically important to not prematurely cut off those channels else we just repeat the same mistakes of the fixed brain era. The second key take away is that plasticity itself is plastic. And I mentioned this in the last episode but I think it bears repeating and emphasizing partly because it’s an important principle on a personal level but also one, if we’re not aware, can and indeed has lead to false interpretations and conclusions about certain observations and data.

If slowing our pace of learning results in the brain down regulating the mechanisms that support it then new learning will become more challenging and I’ve witnessed this type of phenomenon as myself, someone who’s led a life of continuous learning is able to pick up a new and complex skill whether it’s learning a sport or a musical instrument, much more readily than someone of the same age who hasn’t led a life of continuous learning. And in childhood, those mechanisms are up regulated by default, they’re always on as part of the brain’s scripted developmental program. But keeping them on requires continuing to engage them.

And ignorance of this phenomenon will naturally cause us to underestimate the plastic potential of an adult brain. So, if we’re trying to understand what, if any decline in the plastic potential of the brain is due to biological aging by comparing child to adult learning performance, we’d have to control for this phenomenon to answer that question. And not only has this not been done but currently we’d have no idea how to do so because our present state of knowledge is too limited. So, again it’s [inaudible 00:59:25] to the point if not prematurely making conclusions that we cannot support.

And then my third key take away is that not only does our brain’s plastic potential exist throughout our lifespan but its benefits or the benefits of engaging it extend beyond learning or the ability to add new cognitive capacities. And there are now several lines of evidence that support this, which essentially spawn the entire industry of brain games. But, one of the most remarkable is the one mentioned in this interview in which in rats, 20 different age related cognitive processes involved in an auditory discrimination task were reversed through practice and training alone and that included both function and structural reversals. In other words, what we attribute to biological aging was reversed by training which of course begs the question of what we should actually be attributing to the aging process versus what we should be attributing to disuse.

And on the one hand, this seems surprising that the biological and physiological benefits of training and learning should be so robust. But, on the other hand, it makes sense. Our brain is essentially a learning machine and up regulating those mechanisms means that our learning hardware is being kept in peak condition. It has to devote energy and resources to maintaining that hardware and, of course, that really means maintaining all aspects of cognition but it’s still a pretty incredible thing.

So, not only do we possess this ability to alter the structure of our brain through nothing more than thoughts and learning and practice but altering the structure, not only improves our cognitive capacities but also the structural health and integrity of the brain and this also means that not only has the fixed brain dogma been a global constraint on human cognition, it has also had health ramifications in its likely contributions to cognitive decline and dementia and there’s a natural tendency already to learn less as we age and to rely on existing, built cognitive networks that run on autopilot and that idea was further reinforced by the idea that any significant new learning was biologically impossible.

And furthermore as Dr. Merzenich talked about in the interview, we’ve set up our worlds to be easy and our lives to be more convenient. And making it easier and easier to navigate our day on autopilot and disengage entirely. A phenomemon that will likely only amplify with the continued emergence of AI in our lives so figuring out how we can design our lives in ways that are still cognitively demanding and engaging that still require new learning will be an important problem to solve collectively. We already know we’ve paid a heavy price in terms of arranging our lives for convenience so we don’t need to be physically active and it seems we’re transitioning to less active mental lives as well.

Some may say we’ve already made that transition. Personally I think this is where the arts can hopefully fill that need there will always be a demand for humans making great art for each other and in my view, it’s the ultimate brain building endeavor as well because of its wide reaching cognitive demands. So, that’s it for my take aways. Remember that you can find the links mentioned and the full transcript for these episodes by going to and you’ll see a menu of all the prior episodes.

Also, speaking of the arts as the ultimate in brain building activities we are still in the midst of the learn the ukulele challenge inside at the Brainjo collective and even though we’re about three months into it, you can still jump in anytime and all prior lessons are available to you and will remain available to you even after the challenge concludes. And of course we’ll be continuing to do these brain fitness challenges inside of the Brainjo collective as a means of leveraging this magical property of our brain and its brain protecting benefits.

So, to learn more about the learn the ukulele challenge and the brain fitness challenges in general, head over to And lastly, if you enjoy this podcast, it’d be awesome if you left a rating and review in iTunes to help other people find it. I’d really appreciate it. Okay, that’s it for this episode and I will see you next time.

Pioneer of Plasticity Dr. Michael Merzenich