Transcript
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Welcome to Huberman Lab Essentials, where we revisit past episodes for the most potent and actionable science based tools for mental.
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Health, physical health and performance.
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I'm Andrew Huberman and I'm a professor.
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Of neurobiology and ophthalmology at Stanford School of Medicine. Today we're going to talk about an extremely important topic that's central to our daily life and that's motivation. We're going to talk about pleasure and reward, what underlies our sense of pleasure or reward. We're going to talk about addictions as well. We're going to talk about the neurochemistry of drive and mindset. But for now, let's just talk about the neuroscience of motivation and reward of pleasure and pain, because those are central to what we think of as emotions. Whether or not we feel good, whether or not we feel we're on track in life, whether or not we feel we're falling behind. So motivation is fundamental to our daily life. It's what allows us to get out of bed in the morning. It's what allows us to pursue long term goals or short term goals. Motivation and the chemistry of motivation is tightly wound in with the neurochemistry of movement. In fact, the same single molecule, dopamine, is responsible for our sense of motivation and for movement. It's a fascinating molecule and it lies at the center of so many great things in life, and it lies at the center of so many terrible aspects of life, namely addiction and certain forms of mental disease. So if ever there was a double edged blade in the world of neuroscience, it's dopamine. There's a fundamental relationship between dopamine released in your brain and your desire to exert effort. And you can actually control the schedule of dopamine release, but it requires the appropriate knowledge. This is one of those cases where understanding the way the dopamine system works will allow you to leverage it to your benefit. Let's get a few basic facts on the table. Dopamine was discovered in the late 1950s, and it was discovered as the precursor, meaning the thing from which epinephrine or adrenaline is made. Epinephrine is the same thing as adrenaline, except in the brain. We call it epinephrine. Epinephrine allows us to get into action. It stimulates changes in the blood vessels, in the heart, in the organs and tissues of the body that bias us for movement. Dopamine was initially thought to be just the building block for epinephrine. However, dopamine does a lot of things on its own. It's not always converted to epinephrine. Dopamine is released from several sites in the brain and body. But perhaps the most important one for today's discussion about motivation and reward is something that's sometimes just called the reward pathway. For the aficionados, it's sometimes called the mesolimbic reward pathway. But it's fundamentally important to your desire to engage in action, and it's fundamentally important for people getting addicted to substances or behaviors. So how does this work? Well, you've got a structure in the deep part of your brain called the vta. The vta, or ventral tegmental area, contains neurons that send what we call axons, little wires that spit out dopamine at a different structure called the nucleus accumbens. And those two structures, VTA and nucleus accumbens, form really the core machinery of the reward pathway and the pathway that controls your motivation for anything. You can think of them like an accelerator, they bias you for action. However, within the reward pathway, there's also a break. The break or restriction on that dopamine, which controls when it's released and how much it's released, is the prefrontal cortex. The prefrontal cortex is the neural real estate right behind your forehead. You hear about it for decision making, executive function for planning, etc. And indeed, it's responsible for a lot of those. It's this really unique real estate that we were all endowed with as humans. Other animals don't have much of it, we have a lot of it. And that prefrontal cortex acts as a brake on the dopamine system. And that brings us to the important feature of motivation, which is that motivation is a two part process, which is about balancing pleasure and pain. So when you're just sitting around not doing much of anything, this reward pathway is releasing dopamine at a rate of about three or four times per second. It's kind of firing at a low level. If suddenly you get excited about something, you anticipate something, not receive an award, but you get excited in an anticipatory way, then the rate of firing, the rate of activity in this reward pathway suddenly increases to like 30 or 40 times. And it has the effect of, of creating a sense of action or desire to move in the direction of the thing that you're craving. In fact, it's fair to say that dopamine is responsible for wanting and for craving. And that's distinctly different from the way that you hear it talked about normally, which is that it's involved in pleasure. So, yes, Dopamine is released in response to sex. It's released in response to food. It's released in response to a lot of things, but it's mostly released in anticipation and craving for a particular thing. It has the effect of narrowing our focus for the thing that we crave. And that thing could be as simple as a cup of coffee. It could be as important as a big board meeting. It could be a big final exam. It could be the person that we're excited to meet or see. Dopamine doesn't care about what you're craving, it just releases at a particular rate.