Welcome to the Huberman Lab Podcast, where we discuss science and science-based tools for everyday life. My name is Andrew Huberman and I’m a professor of Neurobiology and Ophthalmology at Stanford school of medicine. This podcast is separate from my teaching and research roles at Stanford, but it is part of my desire and effort to bring zero cost to consumer information about science and science related tools to the general public.

In keeping with that theme, I want to thank the first sponsor of today’s podcast, InsideTracker. InsideTracker is a personalized nutrition platform that analyzes blood factors and DNA related factors to help you develop a personalized health plan. Many important factors related to our health and wellbeing can only be measured by a blood sample and by a DNA sample. I’ve been getting my blood work done for many years now.

I use InsideTracker because it makes it very easy to not only get the blood work done (someone can come to your house or you can go to a clinic for instance), but also to interpret the data that you get. Oftentimes when we get blood work done, there are all these numbers and all these levels of different hormones and metabolic factors and so forth. But one doesn’t know what to do with that information. InsideTracker has a terrific dashboard platform where you go online and it makes analyzing all that easy. It also provides some very simple and straightforward directives in terms of exercise, nutrition, and other lifestyle factors that can help guide your health and improve your health. If you’d like to try InsideTracker, you can go to insidetracker.com/huberman and use the code “Huberman” at checkout to get 25% off your order.

Today’s episode is also brought to us by Headspace. Headspace is a meditation app that makes meditating easy. I’ve been meditating on and off for about three decades now, and typically it’s been more off than on. I think like a lot of people, I find it hard to stick with a meditation practice.

I started using the Headspace app a few years ago, and found that I was meditating consistently. The meditations are backed by quality scientific peer reviewed studies, and they are easy and fun to access. I started using them when I would travel, as they are offered as an alternative to watching a TV or a movie on JetBlue flights. I found that I would arrive feeling much more refreshed than had I just zoned out on the TV the whole time, or even if I had slept. I continue to use Headspace regularly, pretty much every day for a short meditation, and I personally derive tremendous benefits from it. If you’d like to try Headspace, you can go to headspace.com/specialoffer and they’ll give you one month of all the meditations that they have available completely free. That’s the best offer available right now from Headspace.

Today’s sponsors are Headspace and Madefor. Headspace is an online platform that offers guided meditations and mindfulness training. You can get one month free by visiting headspace.com/specialoffer. Madefor is a behavioral science company that offers a subscription model in which you engage in specific activities each month for 10 months to bring about positive behavioral change and growth mindset. It was founded by former Navy seal Patrick Dossett and Toms founder Blake Mycoskie. I’m the lead advisor of the scientific advisory board at Madefor. If you want to try it, you can go to getmadefor.com and enter “Huberman” at checkout to get 15% off the program.

We’re also talking about neuroplasticity, which is the incredible feature of our nervous systems that allows it to change in response to experience. It holds the promise for us to think differently, to learn new things, to forget painful experiences, and to adapt to anything life brings us by becoming better. Neuroplasticity has a long and important history and we won’t review all of it in detail today.

Neuroplasticity is the brain and nervous system’s ability to change itself. It is sometimes referred to as neural plasticity, and this process is important for many reasons. We will discuss the different forms of neuroplasticity and how to access it depending on age and the type of changes that need to be made. There are a lot of tools and biological principles we can use to understand this topic.

Neuroplasticity is the ability of the brain and nervous system to change in response to experiences. It can occur in response to both traumatic and positive events. For example, a traumatic event could cause a fear of a particular place or of automobiles and planes, while a positive event, such as the birth of a child or a puppy doing something amusing, could cause a sense of joy. The term “neuroplasticity” means different things to different people, which is why it’s important to understand the science behind it and the tools that can help us access this feature of our nervous system.

When we are born, our nervous system is wired crudely and is primed for learning. Babies have limited control over their bodies and movements, which is evidence of the crude wiring of the brain and nervous system. Neuroplasticity allows us to modify and refine these connections as we learn and grow, giving us the ability to adapt to our environment.

The young nervous system is unable to do much in terms of coordinated movement or speaking with precision. This is because we are born with an overabundance of wires, such as axons and dendrites, which are the different parts of neurons. Imagine a bunch of small roads all connected to one another in a mess, with no highways – this is essentially what the young nervous system is like. As we age, particular connections become reinforced and stronger, while other connections are lost. This process of removing connections that do not serve our goals is known as developmental plasticity or neuroplasticity, and it mainly occurs from birth until age 25.

From birth to age 25, certain events happen that can have a lasting impact on our nervous system. This is known as one-trial learning, where we experience something once and our nervous system is forever changed. Unless we actively work to undo this experience, it will remain with us. During this time, our nervous system is like a web of connections that is not particularly strong in any one area. Our experience shapes our nervous system, customizing it to our unique environment, language, and other factors. Certain parts of the brain become plastic, while other circuits, such as those that control our heartbeat, breathing, and digestion, remain wired and resistant to change. This is a good thing, as it ensures these essential functions remain reliable.

You never want to have to think about whether or not your heart will beat, whether or not you will continue breathing, or whether or not you’ll be able to digest your food. Many nervous system features like digestion, breathing, and heart rate are hard to change, but other aspects of our nervous system are actually quite easy to change. One of the great gifts of childhood, adolescence, and young adulthood is that we can learn through almost passive experience, without having to focus that hard. Children go from being able to speak no language whatsoever to being able to speak many words and comprise sentences, including words they’ve never heard before – which is remarkable. This tells us that the young brain is a plasticity machine, but then right about age 25 plus or minus a year or two, everything changes. After age 25 or so, in order to get changes in our nervous system, we have to engage in a completely different set of processes in order to get those changes to occur and, more importantly, to stick around.

Neuroplasticity is vastly overlooked in popular culture discussion. Carla Shatz’s statement “fire together, wire together” is true, but does not apply in the same way after age 25. There are famous quotes from neurobiologist Ramón y Cajal that suggest it is possible to change the nervous system in any way desired, but what is lost in these statements is how to actually accomplish it. Early in development, the nervous system is connected broadly, making it hard to do anything well.

From birth until about age 25, our brain forms connections mainly through the removal of connections that don’t serve us and the strengthening of connections that relate to powerful experiences or that allow us to do things like walk and talk and do math, etc. After age 25, if we want to change those connections, we have to engage in specific processes which are gated, meaning we can’t just decide to change our brain. We have to go through a series of steps to change our internal state in ways that will allow us to change our brain. Additionally, Costello’s snoring is low rumbling sound and whether or not we can hear it probably relates to the sensitivity of our hearing. We will be talking about perfect pitch and range of auditory detection today. So, whether we can hear Costello’s snoring or not, enjoy!

The nervous system changes after puberty by adding very few if any new neurons. This idea of new neuron addition has a rich history in experimental science and has been observed in rodents and some non-human primates in areas of the brain such as the olfactory bulb and the dentate gyrus of the hippocampus. In humans, the evidence of new neuron addition is more controversial, though it is clear that new neurons can be added to the olfactory bulb.

If any of you have ever had the unfortunate experience of being hit on the head too hard, you may have experienced what’s called anosmia, or the inability to smell. This is because the wires called axons from those olfactory neurons that live in your nose can get sheared off due to passing through a bony plate called the cribriform plate. Fortunately, these neurons can grow those connections back and even reestablish new neurons being added to the olfactory bulb. They come from elsewhere deep in the brain and migrate through a pathway called the rostral migratory stream.

Interestingly, there is evidence that the neurons responsible for smell can be replaced throughout the lifespan, particularly in very young individuals from birth till about age 15 or so. However, it isn’t clear whether or not they’re new neurons added to the hippocampus, the memory center of the human brain. In order to find out, many years ago, Rusty Gage’s lab at the Salk Institute did a study looking at terminally ill cancer patients and injecting them with a label, a dye that is incorporated only into new neurons. After these patients died, their brains were harvested.

New neurons are added to the adult brain in an infinitesimally small number, so all is not lost when it comes to our brain’s ability to adapt and change. Synapses between neurons are strengthened or removed, allowing for new connections to be made and new functions to be developed, such as new memories, abilities, and cognitive functions. This includes the process of grieving and removing the emotional load of a traumatic experience.

Even though we cannot add new neurons throughout our lifespan, it is clear that we can change our nervous system. This is due to the fact that the nervous system is available for change if we create the right set of circumstances in our brain, such as chemical circumstances, and the right environmental circumstances around us. The hallmark of the child nervous system is change, as the neurons can sample different connections easily, removing some and keeping others. As we get older, the extracellular space is filled up by things called extracellular matrix and glial cells, making it harder to change the connections. One of the ways in which we can get plasticity at any stage throughout the lifespan is through deficits and impairments in our sensory apparati, such as eyes, ears, nose and mouth. An example of this is people who are born without a nose and olfactory structures in the brain, so they cannot smell.

In individuals that are blind from birth, the brain can undergo a process called plasticity, where areas of the brain that normally would represent smell become overtaken by areas of the brain involved in other senses such as touch, hearing and sight. For example, the occipital cortex, which is the visual cortex in the back, becomes overtaken by hearing. Neurons there will start to respond to sounds as well as braille touch. In one tragic incident, a woman who was blind since birth had a stroke that took out most of the function of her visual cortex, leaving her unable to braille read or hear. Fortunately, most people don’t end up in this highly unfortunate situation. Studies have shown that blind people who use their visual cortex for braille reading and hearing have much better auditory acuity and touch acuity, meaning they can sense things with their fingers and hearing that typical sighted folks wouldn’t be able to. Additionally, there is a much greater incidence of perfect pitch in people that are blind.

The brain and, in particular, the neocortex, which is the outer part, is designed to be a map of our own individual experience. Experiments of impairment or loss, such as being blind or deaf from birth or having a limb development impairment, show that the brain will represent the body plan that the person has, not some other body plan. However, if someone is injured later in life, they may have less opportunity to use their formerly visual cortex for things like braille reading and hearing due to their changed brain. This is known as the Kennard Principle, which states that it is better to have injuries early in life, although this is not so reassuring for older folks.

There are aspects of neuroplasticity that have nothing to do with impairments. We all have a map of the world around us, allowing us to see edges, colors, and even a map of emotional experience. A few years ago, I was at a course and a woman told me that my tone of voice reminded her of somebody with whom she had a terrible experience. I couldn’t change my voice, but I appreciated that she acknowledged it. Over the two-week course, she would come back and say that it was becoming more tolerable to her. By the end, we had become good friends and still keep in touch. Recognition of something, whether it’s emotional or a desire to learn something else, is the first step in neuroplasticity. Our nervous system has two broad sets of functions, some of which are reflexive (like breathing, heart rate, and walking).

I got up out of my chair and walked out of the door without consciously thinking about each step that I was taking. This is because I had learned how to walk during development. However, when we decide to shift some sort of behavior, reaction, or new piece of information that we want to learn, it is something that we want to bring into our consciousness. This awareness is a remarkable thing because it cues the brain and the rest of the nervous system that when we engage in those reflexive actions going forward, those actions are no longer fated to be reflexive.

To illustrate this idea, I will discuss protocols for how to do this. The first step in neuroplasticity is recognizing that you want to change something. Kids don’t go into school and say that they want to learn language or social interactions, which is the beauty of childhood. The whole brain has this switch flipped that is making change possible. After that, we have to be deliberate and know what it is that we want to change, or at least know that we want to change something about some specific experience.

For example, I was told that my voice was really awful for someone to listen to. This wasn’t meant to make me feel bad, but instead to make it not be the case. Knowing that I wasn’t going to stop talking, the person decided to call it to her consciousness and mine as well.

Recognizing what we want to change or learn can often be the hardest thing to identify. However, the brain has self-recognition mechanisms that are not vague, spiritual, or mystical. These mechanisms are neurochemicals that stamp down particular behaviors, thoughts, and emotional patterns, and tell the rest of the nervous system to pay attention to what we are doing. When we are consciously aware of a change we want to make, chemicals in the brain are released that give us the opportunity to make those changes. Science tells us that there are specific protocols that must be followed in order for these changes to occur. This self-recognition is our prefrontal cortex signaling the rest of our nervous system that something we are about to do, hear, feel, or experience is worth paying attention to.

The biggest lie in the universe that seems quite prominent right now is that every experience you have changes your brain. People love to say this, such as “your brain is going to be different after this lecture” or “your brain is going to be different after today’s class than it was two days ago.” This is absolutely not true. The nervous system doesn’t just change because you experienced something, unless you’re a very young child. The nervous system changes when certain neurochemicals are released and allow whatever neurons are active in the period in which those chemicals are swimming around, to strengthen or weaken the connections of those neurons.

The whole basis of neuroplasticity is essentially ascribed to two individuals, although there were a lot more people involved in this work. Those two individuals go by the name David Hubel and Torsten Wiesel. David Hubel and Torsten Wiesel started off at Johns Hopkins and moved to Harvard medical school.

In the seventies and eighties, David Hubel and Torsten Wiesel conducted experiments recording electrical activity in the brain, specifically in the visual cortex. They were exploring how vision works and how the visual brain organizes the features of the visual world to give us our perceptions. Hubel was a physician and was very interested in what happens when a child has a cataract, lazy eye, or strabismus. They discovered a critical period in which if clear vision did not occur, the visual brain would rewire itself to represent whatever bit of visual information was coming in. To simulate a droopy or deviating eye, they would close one eyelid and found that the visual brain would respond entirely to the open eye, resulting in a takeover of the visual brain representing the open eye. This led to many experiments in many different sensory systems.

The brain is capable of remarkable feats, such as Gregg Recanzone’s and Mike Merzenich’s experiments showing that if two fingers were taped together early in development, the representation of those two fingers would become fused in the brain, so that the person couldn’t distinguish the movements and the sensations of the two fingers separately. This finding was the basis of the Nobel Prize-winning work of David and Torsten, which showed that the brain is a customized map of the outside world. This map measures the amount of activity of a given part of the body, like one eye or a finger, and all of these inputs compete for space in the brain.

Therefore, if we want to change our nervous system in adulthood, we must consider what we’re trying to give up, as we can’t add new connections without removing something else. David and Torsten’s key experiment showed that closing both eyes had no effect, but closing just one eye had a huge effect. This shows that the brain is capable of adapting even to transient changes in its environment.

People’s brains will not change unless there is a selective shift in their attention or experience that tells the brain it’s time to change. These changes occur through strengthening and weakening of particular connections, such as long-term potentiation, long-term depression, and spike-timing-dependent plasticity. To gain a deeper understanding of these concepts, one can refer to Wikipedia pages and explore the paper trail.

In order to bring about a change, an immense amount of attention needs to be devoted to the particular area. This is related to the statement that it all starts with awareness. David and Torsten won the Nobel Prize for figuring out how vision works, which they certainly deserved.

Hubel and Wiesel discovered that this was not the case and that plasticity of the brain was much more dynamic than they had previously thought. They deservedly won a Nobel Prize for their work. David has since passed away, but Torsten is still alive and well in his late 90s. He is still active, enjoying jogging, art, and other activities. Both Hubel and Wiesel were very nice people, and Hubel was also a great Frisbee player, even at the age of 80! Although they made a great contribution to science, they were wrong about the critical period theory. It was thought that if one eye was deprived of input, the visual cortex would be taken over by the open eye and could never be changed. However, Hubel and Wiesel demonstrated that the brain is much more dynamic and plastic than previously believed.

Then, they would put a device on your finger that would vibrate. This device would vibrate at a very specific frequency and they would have you move your finger around in circles and they would record the brain representation of the finger that
was receiving the vibration.

This formed the basis for why a kid that has a lazy eye or a cataract, even though there are some issues with anesthesia in young children, ophthalmologists now know that it is best to get in there early and fix the condition. However, the idea that if you do not act early there is no chance to rescue the nervous system deficit later on is not entirely true.

In the early 90s, a graduate student by the name of Gregg Recanzone, working in the laboratory of Mike Merzenich at UCSF, set out to test this idea. They wanted to know if the adult brain can change if certain conditions are met. To test this, they conducted a series of experiments that were tough on both the experimenter and the subject.

In one experiment, the subject would come into the lab, sit at a table and have their brain representation of their fingers recorded. They would then have a device placed on their finger that would vibrate at a specific frequency and they would move their finger around in circles while the brain representation of the finger receiving the vibration was recorded.

There would be a spinning drum in front of a metal drum that had little bumps. Some of the bumps were spaced close together, while others were spaced far apart. Experiments were conducted to test the subjects’ ability to press a lever whenever the bumps got closer together or further apart. These changes were very subtle and required the subjects to pay attention to the distance between the bumps. Surprisingly, the subjects were not braille readers or skilled in these experiments, yet they could become very good at detecting the distance between the bumps. This showed that the maps of touch were very much available for plasticity, even with fully adult subjects.

They conducted an experiment to prove that the adult brain is very plastic. They had the subject touch bumps on a spinning drum while paying attention to an auditory cue. Every time the tone changed, they had to signal it. This showed that it wasn’t just the action of touching the bumps; they had to pay attention to them as well. This proved that plasticity in the auditory portion of the brain was present, but not in the touch portion. This disproved the idea that every experience changes the way the brain works.

Paying careful attention to experiences opens up plasticity, allowing us to change our brains at any point throughout our lifespan for anything we want to learn. Merzenich and his graduate students and postdocs went on to address the question of why, and it turns out the answer is a straightforward neurochemical one. This chemical is the same one associated with stress, and it can be used to subtract an emotion from an experience, build a greater range of emotion, learn a new language, motor skill, or cognitive-motor skill like air traffic control.

In a future podcast episode, we’ll talk all about stress and tools to deal with it. This is a topic my lab works on quite extensively and I enjoy discussing. In order to change the brain, we have to pay careful attention. This is because two neurochemicals, neuromodulators, are released from multiple sites in our brain, highlighting the neural circuits that stand a chance of changing. The first neurochemical is epinephrin, also known as adrenaline. We call it adrenaline when it is released from the adrenal glands above our kidneys, and epinephrin when it is released from a region in the brainstem called locus coeruleus.

The Locus coeruleus is a part of the brain responsible for sending out axons that “hose” the entire brain with neurochemicals, such as epinephrine. This epinephrine is only released when we are in high states of alertness, and is designed to increase the likelihood that neurons will be active. However, alertness alone is not sufficient for neuroplasticity, as demonstrated by the work of Hubel and Wiesel, who studied brain plasticity in subjects that were either awake or asleep.

And I hate to break it to you but you cannot just simply listen to things in your sleep and learn those materials. Later I’ll talk about how you can do certain things in your sleep that you’re unaware of that can enhance learning of things that you were aware of while you were awake. But that is not the same as just listening to some music or listening to a tape while you sleep and expecting it to sink in, so to speak.

Epinephrin is released when we pay attention and when we are alert. But the most important thing for getting plasticity is that there’ll be epinephrin which equates to alertness, plus the release of this neuromodulator, acetylcholine. Now acetylcholine is released from two sites in the brain. One is also in the brainstem and it’s named different things in different animals, but in humans the most rich site of acetylcholine neurons or neurons that make acetylcholine is the parabigeminal nucleus or the parabrachial region.

There are a number of different names of these aggregates of neurons. You don’t need to know the names, all you need to know is that you have an area in your brainstem and that area sends wires, these axons up into the area of the brain that filters sensory input. So we have this area of the brain called the thalamus and it is getting bombarded with all sorts of sensory input all the time.

I am currently in a room with Costello snoring to my right and my computer to my left. When I pay attention to Costello’s snoring, I create a cone of attention which amplifies the sound of his snoring. This is known as signal-to-noise, which is a concept familiar to those with an engineering background. Essentially, Costello’s snoring becomes more apparent relative to all the other noise in the room. Acetylcholine acts like a spotlight, while epinephrine is for alertness. However, these two components alone are not enough for plasticity. The third component is acetylcholine released from the nucleus basalis in the forebrain.

Nucleus basalis of Meynert is a brain region responsible for releasing acetylcholine. Physicians and medical students should be aware of this. Merzenich and Recanzone, Michael Kilgard and Norman Weinberger from UC Irvine conducted experiments to stimulate the release of acetylcholine from nucleus basalis. They found that when these three brain regions (locus coeruleus, brainstem source of acetylcholine, and basal forebrain source of acetylcholine) are stimulated, whatever the subject is listening to, doing or paying attention to immediately takes over a particular area of the brain, resulting in rapid and massive learning in one trial. This finding is now considered a fundamental principle of how the nervous system works. Furthermore, Hubel and Wiesel’s concept of critical periods in developmental plasticity is further supported by the work of Merzenich, Weinberg and others, demonstrating that when epinephrin, acetylcholine from these two sources are accessed, the nervous system has to change.

It is important to understand that if you want to change your brain, you cannot just passively experience things. Repetition can be important, but the way to use repetition to change your brain is fundamentally different. In Episode One of the Huberman Lab Podcast, I described various ways that people can monitor and change their nervous system, such as brain machine interface, pharmacology, and behavioral practices. These behavioral practices can include dos and don’ts.

In thinking about neuroplasticity, it is important to acknowledge the untapped capacity of combining behavioral practices with pharmacology and brain machine interface. However, I do not recommend that you do anything in particular, as I am not a physician and do not prescribe anything.

As a professor, I profess many things. Ultimately, what you do with your health and medical care is up to you, as you are responsible for your health and wellbeing. I am not going to tell you what to do or what to take, but rather I will describe what the literature suggests about ways to access plasticity. We know that alertness is achieved through epinephrine, and most people accomplish this through a cup of coffee and a good night’s sleep. Therefore, I recommend mastering your sleep schedule and figuring out how much sleep you need in order to achieve alertness when you sit down to learn. For further information on sleep and how to get better at sleeping and timing your sleep, I encourage you to refer to episodes two, three, four, and five of the Huberman Lab Podcast.

Having the ability to engage in deliberate, focused alertness is directly proportional to how well you are sleeping on a regular basis. This is an obvious point, so getting your sleep handled is essential. Once that is in place, the question then is how to access this alertness. There are a number of ways to do this. Some people use elaborate psychological gymnastics, such as committing to a task and creating accountability. This could be done by posting a picture of themselves online and committing to achieving a certain goal, such as losing a certain amount of weight. Alternatively, they can use shame-based practices to potentially embarrass themselves if they don’t follow through.

My friend’s theory is that often times what happens is that people don’t realize that they can access dopamine while they’re working towards the goal, not just when they complete it. People often think that they have to wait until they’re done to get the reward, but that’s not true. People can access dopamine while they’re working towards the goal, enjoying the process of getting there.

People often think they have to wait until they complete a goal to get the reward, but that’s not true. Epinephrine is a chemical and our brains do not distinguish between doing things out of love or hate, anger or fear – all of these promote autonomic arousal and the release of epinephrine. To help with motivation, it is important to identify not just one, but several reasons why you would want to make a particular change. Additionally, we can access dopamine while we are working towards a goal, not just when we complete it. This can help us to enjoy the process of getting there. My friend, a cardiologist, has a theory that this is often overlooked and can be the key to successfully achieving our goals.

Dr. Smith’s theory is that if you receive a lot of dopamine from the reward of people saying “Oh yeah, you’re absolutely going to be able to do that,” you may not go after the reward of the accomplishment itself. He suggests that everyone should ask themselves what is it that they want to accomplish and what is driving them to do it, and come up with two or three things, such as fear-based, love-based, or a combination of both, in order to ensure alertness, energy, and attention for the task.

When it comes to attention, Dr. Smith believes it is one thing to have an electrode embedded into your brain to increase the amount of acetylcholine, but it is another to exist in the real world and have trouble focusing and bringing your attention to a particular location in space for a particular event.

Smartphones and devices have been widely discussed as potentially causing an attention deficit at a clinical level for many adults. This is largely true, however it is important to note that we all have the responsibility to learn how to create depth of focus. Neuroscience offers some principles to help us with this.

People often ask what can be taken to increase acetylcholine levels. Nicotine binds to the nicotinic receptor, which is involved in attention and alertness. A Nobel prize winning colleague of mine chews Nicorette while he works, as he used to be a smoker.

He quit smoking out of fear of lung cancer, which seemed like a smart choice. However, he missed the level of focus that he could bring to his work. This person had a long career, and if you ever meet with him, you can tell he chews five pieces of Nicorette an hour. His theory, which is not scientifically supported yet, is that it offsets Parkinson’s and Alzheimer’s. It is true that nucleus basalis is the primary site of degeneration in the brain in people with dementia and Parkinson’s, which leads to their inability to focus their attention. He might be onto something, although the author tried chewing Nicorette and found that it made him too jittery to focus.

I’ve got friends that dip Nicorette all day, some of whom are scientists, writers and artists. Musicians are familiar with the effects of nicotine from the era where a lot of people smoked, but fortunately fewer people smoke now. If you’re interested in the pharmacology, there are supplements and things that can increase cholinergic transmission in the brain. I’m not suggesting you do this, but if you’re going to go down that route, you want to be very careful how much you rely on those all the time. The essence of plasticity is to create a window of attention and focus that’s distinct from the rest of your day. This is what’s going to create a mark in your brain and the potential for plasticity.

Besides nicotine or Nicorette, the nicotine could come from a variety of sources or things like alpha-GPC or choline. I would encourage you to go to examine.com, the website, and just put in acetylcholine. It will give you a list of supplements as well as some of the dangers of these supplements that are associated with cholinergic transmission.

I would be remiss and I would be lying if I didn’t say that there are a lot of people out there who are using cholinergic drugs in order to increase their level of focus. Since we’re coming up on the Olympics, I don’t want to get anyone in trouble, but I’m well aware that the fact that the sprinters are really into cholinergic drugs because not only is acetylcholine important for the focus that allows them to hear the gun and be first out the blocks on the sprints.

Reaction time is an important factor in winning races. To increase reaction time, athletes often take cholinergic agents, as acetylcholine is the molecule that controls nerve to muscle contraction. Acetylcholine is also important for sport, mental acuity, and plasticity. People should not take Nicorette, smoke cigarettes, or take supplements to increase acetylcholine, but instead focus on ways to increase focus. This can help with school, work performance, and relationships.

Costello never seems to pay attention to anything I say while looking directly at me, which contradicts the fact that the best way to get better at focusing is to use the mechanisms of focus that you were born with. The key principle here is that mental focus follows visual focus. We are all familiar with the fact that our visual system can be unfocused, blurry or jumping around, or we can be very laser focused on one location in space. What’s interesting and vitally important to understanding how to access neuroplasticity is that you can use your visual focus and you can increase your visual focus as a way of increasing your mental focus abilities more broadly.

So I’m going to explain how to do that. Plasticity starts with alertness, which can come from a sense of love, joy, fear, or pharmacologic ways such as caffeine, which reduces the molecule that makes us sleepy called adenosine. I drink plenty of caffeine.

I’m a heavy user of caffeine. I don’t think of myself as an abuser of caffeine, as I believe it can be a relatively safe way to increase epinephrin in reasonable amounts, provided we can still fall asleep at night. Now, many people are also using Adderall, which chemically looks a lot like amphetamine and is essentially amphetamine. It will increase epinephrin release from locus coeruleus, wake up the brain, and is why a lot of people rely on it. Adderall is prescribed for certain clinical syndromes such as attention deficit, but has a high probability of abuse, especially in those who are not prescribed it. Adderall will not increase focus, but increases alertness, and does not touch the acetylcholine system.

People taking Adderall who say it increases their focus overall are likely experiencing an increase in alertness due to the drug affecting their autonomic nervous system. Adderall is problematic for many people as it is habit forming and does not always translate to high performance off or on Adderall at later times. The discussion of Adderall is a broader one and should be discussed with a psychiatrist. An acetylcholine system and the focus it brings is available through pharmacology, but also through behavioral practices. Visual focus can involve looking at a small region of space with a lot of detail and precision or dilating the gaze and seeing big pieces of visual space with little detail.

It’s a trade-off: we can’t look at everything at high resolution. This is why we have the pupil, which more or less relates to the fovea of the eye – the area in which we have the most receptors and the highest density of receptors that perceive light. Our acuity is much better in the center of our visual field than our periphery.

You can do a simple experiment to test this: hold your feet or hands out in front of you and see how many fingers you have. For me, it’s five – and amazingly enough, I can still see all five fingers.

When we move our hand off to the side, we can’t see them with precision. However, when we move our hand back into the center of our visual field, we can see them with precision. This is because the number of pixels in the center of our visual field is much higher than that in the periphery. When we focus our eyes, we tend to do this in the center of our visual field and our two eyes align in what is known as vergence eye movement towards a common point. Furthermore, the lens of our eye moves, so that our brain no longer sees the entire visual world, but rather, a small cone of visual imagery which has much higher acuity and resolution than if we were to look at everything. This makes sense as focus in the brain is anchored to our visual system.

Assuming somebody is sighted, the key to higher levels of cognitive or mental focus, even if engaged in a physical task, is to learn how to focus better visually.

Animals that have their eyes on the side of their head are scanning the entire visual environment all the time, such as grazing animals. However, a bird picking up seeds on the beach or concrete has its head up about a foot off the ground and eyes on the side of its head, yet it has a tiny beak that can quickly pick up these little seeds off the ground with immense precision.

If someone were to try to do this by staring off to the sides of the room and picking up items in front of them with high precision at that tiny scale, they would miss almost every time. Animals do it perfectly and they do it with beautiful movement acuity. So how do they do it?

It turns out that when we lower our head, our eyes very briefly move inward in what’s called a vergence eye movement. This movement shortens the inter pupillary distance and activates a set of neurons in our brainstem that trigger the release of both norepinephrine, epinephrine, and acetylcholine. This results in a smaller visual window and a higher level of visual focus. It also relates to the release of acetylcholine and epinephrine at the relevant sites in the brain for plasticity. Practicing this type of eye movement can help those who have difficulty focusing their minds for tasks such as reading or listening.

Focusing your visual system at the precise distance from the work that you intend to do for sake of plasticity is key. To demonstrate how this works in the real world, let’s say you are trying to concentrate on a science paper, but having a hard time absorbing it. You may think you are only looking at the paper, but your eyes could be darting around a bit. Experiments have been done to show the benefit of spending 60-120 seconds focusing your visual attention on a small window of your screen. This increases not just your visual acuity for that location, but also brings about an increase in activity in a bunch of other brain areas associated with gathering information from this location. To ensure you have the best chance of success, make sure you are well rested, have had your coffee, and are hydrated.

If you want to improve your ability to focus, practice visual focus. You can do this with or without corrective lenses, but it is important to use a clear image. The more you can hold your gaze to the visual image, the higher your levels of attention will be. This is why some people on Instagram tease me for not blinking very often – it is a practiced thing! As we get tired, the neurons in the brainstem that are responsible for alertness and hold the eyelids open start to falter and our eyelids start to close. This is why it can be hard to keep your eyes open when you are tired.

By paying attention and staying alert, our eyes remain wide open. In a paper published in Current Biology, it was shown that blinking can reset our perception of time and space. Blinking is, of course, necessary to lubricate the eyes and prevent them from becoming dry. By focusing our eyes on a particular location and blinking less, we can maintain a tunnel of mental focus. I have worked hard to achieve this, both through a blinking contest with my 14-year-old niece (who still beats me every time) and through my own self-practice.

Now for me, that’s important because I’m mainly learning things on a computer screen. If you’re going to be doing sport, it’s quite a bit different and we can discuss how you might translate to that to sport. In fact, in the next episode, I’m going to talk all about how plasticity and the focus mechanisms relate to learning of movement practices and coordinated movements. It’s an entire discussion unto itself, but the same principle holds.

We need alertness, which can be achieved through mental tricks of motivation, fear or love, as well as pharmacology, though it should be done healthfully. Caffeine, if it’s part of your practice, should be taken with lots of hydration, as this will increase alertness. However, you don’t want your alertness to be so high that all you can think about is the fact that you have to go urinate, as this can be very distracting. You need focus and visual focus is the primary way in which we start to deploy these neurochemicals.

You may ask what about the experiment where people were feeling a rotating drum or listening to an auditory cue that doesn’t involve vision at all. If you look at people who are learning things with their auditory system, they will often close their eyes. This is not a coincidence; if somebody is listening very hard, they should not be asked to look you directly in the eye while also listening to you. This is actually one of the worst ways to get somebody to listen to you. When you ask someone to both listen and look at you, the visual system will take over and they will focus on your mouth movements rather than what you are saying. Closing the eyes is one of the best ways to create a cone of auditory attention. This is what low vision or no vision folks do, as they have tremendous capacity to focus their attention in particular locations.

Two animals with the best hearing in the world are the elephant and the moth. Elephants have huge ears, so this might not come as a surprise. However, the fact that moths have exceptional hearing may be surprising. This explains why they are so hard to catch. People who are not sighted learn to do things with their hearing, while people who braille read learn to do things with their fingers. Great musicians like Glenn Gould, Stevie Wonder, and other blind musicians often turn their heads to the side when playing. This is due to their heightened hearing.

He would look away because he had no reason to look at the keys, but oftentimes they’ll orient an ear or one side of their head to the keys on the piano. People who are non-sighted have better pitch and can devote more attention to the task at hand. Vision is usually the primary way to train up this focus of building these cones of attention.

When learning something new, it is normal to feel some agitation due to the epinephrine in the system. If feeling agitated and challenged to focus, chances are one is doing it right. Practicing the ability to stare for long periods of time without blinking can be an immensely powerful portal into mechanisms of plasticity, such as nucleus basalis.

I get a lot of questions about attention deficit hyperactivity disorder (ADHD) and attention deficit disorder.

Some people have clinically diagnosed ADD or ADHD and should work with a good psychiatrist to determine the best pharmacology and/or behavioral practices. Others have given themselves a low grade ADHD or ADD due to their reliance on their phone. This is because phones are small and easy to limit our visual attention to, and they contain movies which naturally draw our attentional system.

But I’m aware of the fact that if I’m really trying to build my brain, I need to focus on the more tedious tasks.

It is harder to read words on a page than it used to be for many people, because we are used to seeing things spelled out for us in YouTube videos or videos where things move in a very dramatic way. We are getting worse at attending to things like text on a page or listening to something like a podcast and extracting the information. Therefore, many people have asked why there aren’t intense visuals to look at. The answer is that many people are consuming content through pure auditory, by listening.

It is important to attend to things, even if it is fleeting, because it has a much more powerful effect in engaging the cholinergic system for plasticity than watching a movie. When watching a movie, it can be an overriding experience, but one has to ask how much of their neurochemical resources are devoted to the passive experience of letting something overwhelm them, versus something they are trying to learn and take away. It is important to enjoy movie and TV content, but if one is trying to build their brain, they need to focus on the more tedious tasks.

We are limited in the extent to which we can grab a hold of these acetylcholine release mechanisms or epinephrine. I think that we need to be careful that we don’t devote all our acetylcholine and epinephrine, all our dopamine for that matter, to these passive experiences of things that are not going to enrich us and better us.

The real question is is the information rich for us in ways that grow us and cultivate smarter, more emotionally evolved people, or is it creating what’s it doing for our physical wellbeing for that matter? I don’t want to tell people what to do or not to do, but think carefully about how often you’re focusing on something and how good you are or poor you are at focusing on something that’s challenging.

Once you get this epinephrine, this alertness, you get the acetylcholine released and you can focus your attention. Then the question is for how long? In an earlier podcast, I talked about these ultradian cycles that last about 90 minutes. The typical learning session should be about 90 minutes and I think that learning session will no doubt include five to 10 minutes of warmup period.

I think everyone should give themselves permission to not be fully focused in the early part of a task. However, for the middle hour or so, it is possible to maintain focus. To help with this, I eliminate distractions by turning off the wifi and putting my phone in the other room. If I find myself reflexively getting up to get the phone, I will take it and lock it in the car outside. If I find myself going to get it anyway, I give away the phone for a period of time or even do something more drastic, like throwing it up on my roof! This is to help me experience what it is like to be completely immersed in an activity, even when I feel the agitation that my attention is drifting. It is important to remember that attention drifts, but we have to continually bring it back and re-anchor it.

Learning can be greatly increased by maintaining visual focus on the thing that is being learned. This is based on the work of Merzenich, Hubel and Wiesel and others. Neuroplasticity, however, does not occur during wakefulness but instead occurs during sleep. If one can focus on something for around 90 minutes or so, and even do multiple bouts of learning per day, then the neural circuits highlighted with acetylcholine transmission will strengthen and other will be lost. This is the essence of plasticity and means that when one wakes up a couple of days or a week later, they will have acquired the knowledge forever, unless they actively unlearn it. Therefore, mastering sleep is key in order to reinforce the learning that occurs.

Poor sleep can have a negative effect on learning. However, if a person sleeps the next night or the following night, learning will occur due to a stamp in the brain where acetylcholine is released. This marks the synapses neurochemically and metabolically, making them more likely to change. Without deep sleep, these changes may not occur. Non Sleep Deep Rest (NSDR) protocols can be used to partially bypass the need for deep sleep. Last year, a study published in Cell Reports showed that people who engage in these protocols after a difficult spatial memory task had significantly higher rates of learning than those who simply had a good night’s sleep the following night. Therefore, NSDR protocols or brief naps of 90 minutes or less can accelerate learning.

The key to plasticity in childhood is to be a child. The key to plasticity in adulthood is to engage alertness, focus, and Non Sleep Deep Rest while getting a typical amount of sleep. I’m often asked how many bouts of learning can be performed. People who train their visual focus mechanisms can do up to three or four 90 minute bouts throughout the day, with some inserting Non Sleep Deep Rest. To recover from these intense bouts of learning, motor activities like walking, running, and cycling should be done. This gets into self-generated optic flow, which is the opposite of a tight window of focus. This type of activity shuts down areas of the brain like the amygdala, which are involved in releasing epinephrine and creating alertness.

Neuroplasticity is its own form of non-sleep deep rest. Some people find it much more pleasurable and practical to engage in a focused amount of learning and then go do an activity that involves “worldlessness” where you’re not really thinking about much of anything. Listening to audio books or podcasts while running may be enjoyable, but it’s much more important to get the benefits of neuroplasticity. After a period of deliberate, focused effort, letting the mind drift where it’s not organized in thought is the best way to accelerate learning and deepen learning. There is scientific data to support this, including the Cell Reports paper that was mentioned. This month is about neuroplasticity and today’s episode has covered a lot, but not all of the potential and protocols for plasticity. We will get into all of it.

Today I want to make sure that the key elements that form the backbone of neuroplasticity are embedded in people’s minds. Plasticity occurs throughout the lifespan, from birth until 25, and mere exposure to a sensory event can create plasticity. This could be a good or bad thing, and we will discuss how to unlearn the bad stuff, such as traumas, in a subsequent episode this month.

Adults must be alert to learn, and this might seem obvious but many people don’t think about when in their 24 hour cycle they are most alert. There are four episodes devoted to this 24-hour cycle and the cycles of alertness and sleep, and I encourage people to listen to these if they haven’t had the opportunity to yet, or just ask themselves when during the day they tend to be most alert. This will give them an advantage when learning specific things during that period of time.

Don’t give up that period of time for things that are meaningless, useless, or not aligned with your goals. That would be a terrible time to get into passive observance or just letting your time get soaked away by something. Attention is something that can be learned and is critical for creating the condition where whatever it is you are engaging in will modify your brain in a way that you won’t have to spend so much attention on it going forward. That is the essence of plasticity – that things will eventually become reflexive.

The language you are learning, motor movement, cognitive skill, and the ability to suppress or engage in emotional responses depending on your goals and what is appropriate for you can be increased through acetylcholine. This can be done pharmacologically through nicotine, but there are certain dangers and costs associated with this. An alternative is to engage the cholinergic system through the use of the visual system – practicing how long you can maintain focus with blinks as you need them, and how long you can maintain visual focus on a target, such as a piece of paper a few feet away or at the level of your computer screen. Additionally, pharmacologic practices like caffeine and hydration can support heightened levels of alertness.

People in communities where high levels of visual focus are necessary often have to employ strategies to harness the mechanisms of attention. One way to get high levels of visual focus and alertness is to have a panic or a very bad situation. This will immediately cause a person to be focused on everything related to that situation, but this is an unfortunate way to get attention. A better way to get attention is to use the auditory system, either because of low or no vision, or to learn something that relates more to sounds than to what is seen. This can be used to learn cognitive information or to understand the nuance in a partner’s explanations. Lastly, it is important to remember that if someone wants to be heard, they should not expect the listener to look directly at them while they are speaking as this will limit their ability to focus.

I was joking earlier that I’m very familiar with the struggle of having ADD or ADHD, but I know that one can get better at listening, learning, and all sorts of things by anchoring in these mechanisms. Now, people can also decide to combine pharmacology with these learning practices. Many people in communities do this naturally by drinking coffee before they learn. However, I would also encourage you to think about how long these learning bouts are. If you think you have ADD or ADHD, you should see a clinician, but also ask yourself if you are giving up your best period of focus to something that doesn’t serve you well, or if you are devoting that period to learning. Additionally, ask yourself if you are trying to focus too much for too long during the day. High-performing individuals rarely focus all day long.

Many people take walks or go for bike rides, not trying to engage their mind at maximum focus all the time. This is because we learn best in 90-minute cycles, which should not be expected to be focused for the entire period. The beginning and end of each cycle can be a bit unfocused. It is possible to tap into these cycles when engaging in learning practices. After learning, it is beneficial to get some non-sleep deep rest or deliberate disengagement such as walking or running, or just sitting with eyes closed or open. This accelerates the rate of plasticity that has been shown in quality peer-reviewed studies, as well as deep sleep.

Plasticity is your natural right early in life, but after about age 25 you have to do some work in order to access it. Fortunately, experiments by Hubel and Wiesel, Merzenich, Weinberger and others point in the direction of what allows us to achieve plasticity, such as neurochemicals and circuits. We now have behavioral protocols that allow us to do that, as well as other practices that involve repetition and incorporating the reward system that involves dopamine.

This kind of plasticity comes from extreme focus and alertness, which can be achieved through difficult events that you didn’t want. However, your brain is designed to keep you safe and can get one trial learning from things like touching a hot stove or engaging with a really horrible person. On the other hand, you can also get incredible plasticity of positive experiences from things that you want by engaging in this high focus regime, as well as rest, non-sleep deep rest, and sleep.

There is another aspect of plasticity which we will explore in the next episode, as well as when we explore movement-based practices for enhancing plasticity and plasticity of movement itself. These practices are not high in attention or emotionality, or intense experiences. They are more about repetition and reward, repetition, reward, repeat, and are used for a distinctly different category of behavioral change, more of which relate to habits as opposed to learning particular types of information.

I’m sure there are a lot of questions, so please put your questions in the comment section below. This entire month, we will be exploring neuroplasticity, so if you have specific topics related to neuroplasticity that you would like me to cover in the subsequent episodes this month, please go to YouTube, subscribe, and leave your question in the comment section of this episode. I will be sure to read them and respond.

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Thank you for your time and attention, and for your interest in science. [upbeat music]