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Dopamine.
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You've probably heard of it.
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I've come across the trend of the dopamine detox.
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What you're doing is chasing the most refined dopamine loop that software has ever produced.
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Today we are going to talk all about dopamine.
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Porn addiction is very much about dopamine.
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Three natural ways to boost your baseline dopamine levels.
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And you see very little dopamine transmission.
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They are in a chronic dopamine deficit state.
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Dopamine.
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I know it's just dopamine.
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Dopamine.
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But it feels so real to me.
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Dopamine.
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I know it's just dopamine.
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But is it?
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I made that for you.
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Was that you doing the Robyn cover?
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That was you secretly auto-tuning yesterday?
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Uh, yeah, you left for about an hour and I became Robyn
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That's incredible.
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I'm so happy about this it seems like dopamine does a lot a lot to us, if not like sociologically, if not biologically.
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I just felt like, in, just in those clips alone, right?
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It's a good thing, it's a bad thing.
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You should fast, you should try to increase it.
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And like, what is the real story here?
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What should we actually know about dopamine?
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What is it actually doing in our brains?
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And like, how much do we actually know versus how much is this sort of like conversation about it and where we're just plugging in dopamine when we really mean something else?
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Hmm.
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Yeah, my main impression about this whole thing is, I mean, my level of knowledge of this is, like, maybe a psychology 101 undergrad class where there was a box that said dopamine, and there was, like, an arrow that pointed to, like, reward.
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And that's my level, and you hear this phrase everywhere.
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I've certainly seen it everywhere in discussions about AI and coding, but I also saw it way before that.
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Like, I saw it with, discussions about should kids use social media?
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What is the internet doing to us?
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Like, kind of plug in the technology of the day, and there was a dopamine discussion for the last five years or something.
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So I'd love to hear your take.
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Dopamine is one of these scapegoats.
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Like, whenever we're upset about something, we're like, "Yeah, it's dopamine." Like, it's, it's smartphones, it's, like, AI, it's whatever you're upset about in society.
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Well, it's because we're fucking up our dopamine.
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And I feel like in so much of this conversation, dopamine has been wronged, you know?
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And like, and so in some ways, I'm here today in defense of dopamine.
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It's not a bad thing.
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It's actually a necessary thing.
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We're gonna talk about some of the things it does in your brain that are non-negotiable.
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Like, you need it.
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I'm sorry, but you can't dopamine fast.
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Like, you, you kinda need it.
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Um, and I think one really interesting thing to me is that even though dopamine right now in the current cultural zeitgeist is the villain, this actually hasn't always been the case.
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In preparing for this episode, I revisited this piece that I love by, um, computational neuroscientist Mark Humphries.
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He's over in the UK.
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He wrote this piece nine years ago called Crimes Against Dopamine.
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I send it to everybody anytime a conversation about dopamine comes up, basically.
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And I opened it up again, and the funniest thing is that in the intro to his piece, he's actually talking a little bit more about how dopamine at the time is framed as a positive thing.
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Like, it's something you should increase if you wanna get motivated.
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It's an explanation for why we love things, like why we love storytelling, for example.
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Oh, like across society we were saying, "Wow, none of us have enough dopamine," at the time, and now we think we have too much
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Yeah, exactly.
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The conversation around it was, was totally different.
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And again, it's just because it's just become the thing that we point to, or one of the things we point to.
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So I wanted to talk a little bit today about like what is dopamine?
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What does it do?
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You said you had a psychology explanation of it.
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Is there anything else you kind of pull out of your like archives of psychology
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Yeah, I'm gonna have to sit here and represent the person who truly doesn't know anything here.
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Um, this is just absolutely not a world that I know much about in terms of neurotransmitters, chemicals in the body.
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I'll sit here and be the audience.
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Like, I know we have chemicals in our body.
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I know that they get modulated by various things.
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Um, you know, maybe the biggest thing I feel familiar with is, like, antidepressants, right?
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So sometimes you end up not having enough of something.
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Um, I know about addiction.
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I know that there are biochemical, very, like, in your body physiological things that happen to people when they are addicted to things.
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Um, I know that that's scary.
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It's scary to imagine that you can get pulled into behaviors like that.
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Um, I wonder about things like the gut biome.
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I wonder about things like, uh, you know, we're increasingly talking about, oh, maybe your, your diet changes your s- I, I know a lot more about serotonin than I know about dopamine, so you know, serotonin's in your gut, right?
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There's a lot of
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Mm-hmm.
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So
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confusing things out there.
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Yeah, well, see?
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There you go.
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Everything is everywhere, and I start, I start, I start, yeah, all at once, and I start to wonder about things like, um, do, does the stuff I do have a really targeted effect?
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Like, do some- does the food I eat impact the, the dopamine in my gut but not in my brain?
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Or what...
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You know, do they have to be at different levels?
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Are people right about this idea that you could get into, like, a deficit or a state that's bad where you're not getting the right feedback, you know?
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From the psychology point of view, I also know a lot about self-regulation, so I know about the kinda psychology level of this.
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It is hard for people to regulate.
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It is hard for people to kinda get out of bad habits.
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So what role does all of this play?
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That's a lot, but
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Yeah.
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No, that, that's a really good sort of set of questions, a really good sort of scan of the landscape.
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And I think, the challenging thing is to many of your questions, like for example, the question of, you know, if I play a video game for an hour, does it increase my gut dopamine or does it increase the dopamine in my, like, reward centers?
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And the answer to that is, like, we don't really entirely know, and as we're gonna get into a little bit later, it's actually really hard to study this directly in humans.
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It's extremely limited.
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You know, but generally speaking, yeah, dopamine, just like serotonin, is a neurotransmitter.
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These are signals, chemical signals that your brain uses to communicate.
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You've got it in multiple parts of your brain and your gut, as we just said.
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Um, so something I learned yesterday as I was doing some research for this is that you actually have dopamine in your eyeball.
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Um, it's helping regulating eye growth.
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Yeah.
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Yeah.
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So it's there.
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Um, another really big place where dopamine plays a role is in this set of brain structures called the basal ganglia.
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This is, a set of brain structures for movement, and this is the area of the brain where dopamine is impacted in Parkinson's disease.
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What happens in Parkinson's disease?
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So in Parkinson's disease, a particular set of neurons in one brain region that release dopamine, um, degrade.
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They start to degenerate.
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We don't entirely know why.
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But yeah, so some of our treatments for Parkinson's, one of the mainline treatments is replacing dopamine, basically giving people either dopamine directly or precursors to dopamine to help increase the amount of dopamine in their brain.
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But then, you know, when people say dopamine, when we're talking about, like, dopamine hits or whatever, they're really talking about the dopamine in your midbrain, which is, like, the core of your brain.
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It's kind of the reward circuitry, the reinforcement learning circuitry.
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It's where we build habits, where we learn to do things through reinforcement or no reinforcement.
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So dopamine hits are real
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Well, there's like a thing that's a dopamine hit, but it's not exactly what people mean when they say dopamine hit.
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And this is the thing that like if you talk to any neuroscientist who studies this stuff, it's the thing that like really rubs them the wrong way about all of this conversation, which is that people equate dopamine with reward, right?
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But really, dopamine is a reinforcement signal.
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It's not the this feels good signal, it's the I want more signal.
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And that's actually a big distinction
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Um, can you unpack that a little bit for me?
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Aren't rewards the thing that reinforces you?
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Like what do you mean by that difference?
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Yeah, totally.
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So it's, it's subtle, right?
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But if we're gonna think about how the brain works and we're gonna try to understand how the brain works, we have to make this distinction.
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And so this brings us to, like, the classic study of dopamine.
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Everything that kicked off our understanding of reinforcement learning, all of the stuff about reinforcement learning and machine learning right now is based on this, 1997 study, by a group of people.
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They actually ultimately got a one million euro brain prize for this work.
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It's, like, really, really big deal.
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And what they did was they were recording from a monkey from those midbrain dopamine neurons that we were talking about, and they're doing, like, a classical conditioning experiment.
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So in a classical conditioning experiment, you're, like, pairing some tone or something with a reward.
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And they notice that when the monkeys get a reward that they are not expecting, there's this, like, little burst of dopamine in their brain.
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It's like, "Ooh!" Like, "What is that?" And I think this is, like, the thing that, you know, this...
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That was better than predicted.
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That's kind of the signal that those neurons are
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Oh, so it's kind of like discovery.
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It's not like, "Oh, I expect this reward," which is maybe like the more compulsive behavior stuff.
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Like, "Oh, I expect this, and I want it, and I can't get out of it." You're more talking about like your brain wants to reward you.
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You go to a new bush and discover a new kind of berry you didn't know about, your brain really wants you to remember about that.
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Totally.
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It's like, "Oh, the bush has the berry.
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Like, how cool.
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Like, that was better than I expected."
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But you go back to the bush, you already know about the berry, it's like a main food supply, you're not gonna get that same reward.
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Is
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When you go back to the berry...
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Yeah, this is, this is-- I love this example.
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So when you go back to the bush, those neurons don't fire when you get the berry.
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They actually fire at the sight of the bush.
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So this is the main finding of this paper, is that the signaling shifts.
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So initially, the signal is, "Wow, that was awesome, better than expected." And then the signal shifts to be more tied to the thing that triggered the reward, which in this case, in your example, is, like, the bush.
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So you see the bush and you're like, "Oh, there it is.
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I'm gonna go back and get it." So it's the signal that reinforces the behavior.
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It, it teaches you.
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It's a learning signal.
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It teaches you to go back to that thing that gave you a better than expected reward.
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Hmm.
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So what does this change about, like, the way that people talk about it in social media or out there in the world?
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Like, what what's the misconception that you keep seeing?
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Well, I think it's just like a sloppy representation of what the brain does.
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Um, you know, I think like this particular point has less of a severe implication for the conversation about it because at the end of the day, what people are ultimately trying to do is they're just trying to like tie it to some brain circuitry.
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And, and in this case, they're just tying it to the wrong thing.
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So even though like dopamine ultimately as you learn things does start to get released as you feel good because it's this conditioning system, it's tied to it ultimately, the actual like signal in the brain that it is is just not that feel-good system.
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That's actually more of like opioids, for example.
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So it's kind of funny we don't say like, "Oh, I got an opioid hit." Like no one says like, "Oh, I got an endogenous opioid hit whenever whenever I like did this particular
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yeah.
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Okay.
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Yeah.
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I'm already taking away the feeling of just kind of like this is a little bit more complicated than like thing happens, I get reward, now I'm trapped, and I can never get outside of that loop because, there's all sorts of other circuits ha- you know, being activated.
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And like one implication that I'm taking from it is if you see a study or a piece of evidence out there that says, "Look, you know, when people did X, like the dopamine increased," or, "When rats pushed a lever, the dopamine increased," that's really not telling you about everything that we experience in our day as we're like making choices about our own behaviors.
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It's like the worst case of biological reductionism where, like, you're, you're reducing this thing that is really complicated, you know.
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As you know, like, habit formation, as you mentioned earlier, self-regulation, there's all of these systems in the brain and the body that are here to, like, help us regulate our behaviors.
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It's not as simple...
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Like, we are, we are not as simple beings as, like, we do a thing and it feels good and we get reinforced for it, and then we keep doing it.
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Like, there's this endless cycle that is feeding back on that kind of behavior.
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Maybe one big takeaway is that this is a kind of negative, pessimistic view of what humans are like.
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We're not this, this simple feedback loop, you know?
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And, and you are also not subject to your own, quote-unquote, "dopamine," you know, or c- call it whatever molecule you want
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So I have a question for you.
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Does this mean that you can engineer your dopamine because of the way that you think about the world and the way that you expect things?
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So like if you change your own expectations of, what you're gonna get Like I'm thinking about my world of, like expectancy value, you know, motivation cycles, and like if you change your expectation of what's gonna happen when you tackle a math problem and you say, "Oh, I'm gonna, I'm gonna actually see the friction as a good thing that's g- giving me a reward, that's telling me I'm working hard, and working hard is good, and I like that, and it's progressing me towards my goals." Like you can deeply change how aversive people find that experience and the meaning they take from it.
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So that's like the psychology level.
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Is it connecting to biology?
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Like is it changing the type of dopamine you're getting in the classroom, you know?
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Okay, so this is a really good question.
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I love that you asked this because I've been thinking a lot about expectancy effects for the book that I'm writing, actually.
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Because, you know, for example, when people get a placebo drug but they still get better, that's largely due to expectancy.
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They expected to get better, and so something must be happening in the brain when they expect to get better.
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And it's probably not mostly dopamine.
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Most of the research points to your internal opioid system.
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We call them the endogenous opioids.
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Uh, most research points to that being really important.
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Dopamine is almost definitely involved at some level because, as I mentioned earlier, it's the learning signal.
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It's the thing that's gonna ultimately reinforce the behavior.
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But expectancy itself probably manifests in the brain a little bit more with opioid signaling.
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That said, when we think about habit formation or even addiction, it is absolutely true that dopamine in the brain is changing.
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I mean, this is one of the biggest findings, and it's mostly people's background tonic dopamine levels.
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It ends up being that you need, a bigger hit in order to get that same feeling, in order to get that same reinforcement.
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So that is something, you know, that I think is worth thinking about, that maybe we have some lever of control over.
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It's not as simple as, oh, you shouldn't over-pleasure yourself because you're gonna, like, screw up your brain, right?
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That's kind of like "Dopamine Nation's" main point, right?
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And it's
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a next question I have, which is like, how much does your body actually keep this in balance?
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And like when should you get worried about it?
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And how, how easily, how easy is it to knock this system off its homeostasis, you know?
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Yeah, and that's,
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Are we all addicted to our phones, or is addiction the wrong metaphor?
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Addiction is like a very, you know, in, in the research, addiction has a very particular definition which people have debated over, right?
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In a simple version of it, it's a behavior that if you don't do, you go through withdrawal.
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So if you don't have withdrawal symptoms from your phone, then you're not addicted to it, at least by that one definition.
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Ooh.
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Can you define, like what are withdrawal symptoms like actually?
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Yeah, withdrawal you could define either behaviorally or, biologically, right?
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You have, like, some negative response to not having the drug or not having the thing, right?
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So it's a hu- it's a hangover,
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But I would say it, it's a very strong negative.
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It's a very strong threshold to meet because you-- it can't just be, "Oh, I miss it.
00:16:59.957 --> 00:17:02.337
Oh, I like doing this." That's just a bad habit.
00:17:02.337 --> 00:17:05.817
Like, I, I like doing this thing and it's a little bit bad for me.
00:17:05.817 --> 00:17:13.807
Like, you wouldn't say that students are addicted to procrastinating, even if they have a longstanding, deeply ingrained habit of doing it.
00:17:13.807 --> 00:17:21.067
It doesn't rise to the level of addiction because a- addiction withdrawal in psychology, in the clinical sense, is, like, very severe.
00:17:21.067 --> 00:17:29.298
It's, like, impacting your daily life functioning, and I don't just mean, like, you were an A student and now you're a C student.
00:17:29.298 --> 00:17:34.278
I mean, like, very y- big, you know, breakdown of relationships kind of stuff.
00:17:34.278 --> 00:17:50.688
And that's something that bothers me kinda out there, is this calling everything addiction, because I actually think addiction's this enormously sensitive, you know, profound problem in the world where we have a lot of people suffering, and there's been a lot of misconception about it.
00:17:50.688 --> 00:18:03.637
There's a great paper that is about, um, how easily we pathologize stuff that comes up with a measure of, like, being addicted to offline friendship, so, like, hanging out with your friends in real life.
00:18:03.637 --> 00:18:15.698
And they take one of these survey measures that people have used to study, quote-unquote, "social media addiction," and they, like, run it with people, but they just change the items to make it be about hanging out with your friends.
00:18:15.698 --> 00:18:26.317
And, and they're like, "Look, people are addicted to having friends, and they have withdrawal if you don't have them." You know, and it's just a way to show basically that these measures are bad.
00:18:26.317 --> 00:18:35.307
They're very badly constructed, and you can kind of create the appearance of addiction if you use these sloppy, broad, vague measures.
00:18:35.307 --> 00:18:40.417
So that's something that, you know, I, I feel like is really interesting to think about.
00:18:40.759 --> 00:18:41.230
Yeah.
00:18:41.230 --> 00:18:49.539
I, it really feels like we pick and choose the things we call addictive versus the things we call, you know, like pleasurable or just good for us or nice to have, you know?
00:18:49.539 --> 00:18:56.440
Obviously, I think very few people would disagree with the idea that friends are good for you, you know?
00:18:56.567 --> 00:19:02.407
Are, are there like things that give us, quote, these dopamine hits that are not, you know, nobody's worried about?
00:19:02.407 --> 00:19:06.067
Like, I would think listening to music or video games.
00:19:06.067 --> 00:19:17.837
I guess, I guess some people talk about video game addiction, but that seems like an activity that we trust that a lot of normal people can do, and we're not, like, regulating it, you know, for addiction, right?
00:19:18.263 --> 00:19:19.223
Yeah, totally.
00:19:19.223 --> 00:19:24.054
I mean, probably when video games first came out, people were like, "Oh my God," like, "The kids are addicted."
00:19:24.480 --> 00:19:25.089
Oh, they were.
00:19:25.089 --> 00:19:25.920
Yeah, absolutely
00:19:26.894 --> 00:19:27.034
I
00:19:27.069 --> 00:19:28.940
there still is that in religious circles
00:19:29.720 --> 00:19:31.490
That's, yeah, no, that's fair.
00:19:31.490 --> 00:19:32.140
But, uh,
00:19:32.221 --> 00:19:37.811
A- as you play Hades, Ashley's playing Hades right now, very intensely playing Hades.
00:19:37.811 --> 00:19:41.241
Are you caught in, like, a dopamine loop playing Hades?
00:19:41.526 --> 00:19:42.226
probably.
00:19:42.226 --> 00:19:45.256
I mean, yeah.
00:19:45.256 --> 00:19:54.905
I mean, I, I think the key thing here is that, like, things that are addictive usually feel good, but not everything that feels good is addictive, right?
00:19:54.905 --> 00:19:56.965
This is, like, something we have to tease apart.
00:19:56.965 --> 00:19:58.486
These things are not the same.
00:19:58.486 --> 00:20:01.336
Um, and, and you could replace dopamine for that, right?
00:20:01.336 --> 00:20:07.556
Like, things that involve dopamine usually feel good, but not everything that involves dopamine is addictive.
00:20:07.556 --> 00:20:09.486
Like, same, same logic.
00:20:09.486 --> 00:20:15.195
So right, your question, do video games invoke dopamine in your brain?
00:20:15.195 --> 00:20:15.996
Absolutely.
00:20:15.996 --> 00:20:43.625
In fact, that's the perfect example because this was probably the first time we ever measured dopamine release in humans, um, and showed that when people were playing this, like, kind of silly video game where they were, like, in a battle tank just driving around, like, collecting stuff, um, they had dopamine release in the same areas of the brain that, you know, signal rewards, so the middle of the brain.
00:20:43.625 --> 00:20:46.465
And, um, that was in 1998, right?
00:20:46.465 --> 00:20:47.125
That's not that long
00:20:47.208 --> 00:20:48.387
how are we measuring that
00:20:49.125 --> 00:20:49.476
Right.
00:20:49.476 --> 00:20:59.915
So yeah, so this is probably one of my biggest pet peeves about the conversation around dopamine, which is it's very hard to measure dopamine in humans.
00:20:59.915 --> 00:21:10.888
So we have kind of one good main way, which is with something called positron emission tomography, and, or PET scanning.
00:21:11.025 --> 00:21:11.924
ah, that's a PET scan,
00:21:12.288 --> 00:21:12.929
Yeah,
00:21:13.204 --> 00:21:14.684
I didn't know what that stood for.
00:21:14.684 --> 00:21:18.414
Positrons, that sounds so 1960s sci-fi.
00:21:18.898 --> 00:21:19.318
Yeah.
00:21:19.318 --> 00:21:19.818
Yeah,
00:21:19.944 --> 00:21:22.065
so w- what does a PET scan do?
00:21:22.608 --> 00:21:30.818
So in a PET scan, you first get injected with something, so it's actually a little bit invasive, which is one of the things that makes this difficult to do.
00:21:30.818 --> 00:21:37.278
Not everybody, even for 25 bucks or an Amazon gift card or whatever, wants to get injected with a radioactive tracer.
00:21:37.278 --> 00:21:38.749
Um, but that's what happens.
00:21:38.749 --> 00:21:41.729
And you use different tracers for different kinds of experiments.
00:21:41.729 --> 00:21:45.058
There's a particular one that people use for dopamine.
00:21:45.058 --> 00:21:55.179
And it's very cool actually, because what this tracer does is it gets into your brain, and then it competes with dopamine for the same sites it would normally bind to.
00:21:55.179 --> 00:22:04.939
So when you have more dopamine release in your own brain, dopamine's gonna out-compete the tracer, and the tracer, um, visibility goes down basically.
00:22:05.163 --> 00:22:06.143
Oh, how neat.
00:22:06.143 --> 00:22:12.593
You're exploiting this mechanism of how these chemicals, like, connect to your brain Wow, that's so cool.
00:22:12.593 --> 00:22:15.843
There's so many little techniques in neuroscience that are, like, so clever like this
00:22:16.270 --> 00:22:16.691
Yeah.
00:22:16.691 --> 00:22:17.441
Yeah, totally.
00:22:17.441 --> 00:22:24.810
So many people have done PET scanning in humans and yeah, like, there's this 1998 study in video games.
00:22:24.810 --> 00:22:29.230
Um, there's a more recent study about music causing dopamine release.
00:22:29.230 --> 00:22:50.760
And then of course, you know, one of the biggest areas this has been used in is the study of drug addiction, And so, um, Nora Volkow, who was,, director of the National Institute of Drug Abuse for many years, she has, like, a whole body of amazing work showing how drugs like cocaine change the dopamine system, and this is largely based on PET scans like the one I just described.
00:22:51.384 --> 00:22:51.884
Yeah.
00:22:51.884 --> 00:22:56.005
This is bringing something up for me, which is kind of this like maybe fallacy.
00:22:56.005 --> 00:22:56.875
You tell me.
00:22:56.875 --> 00:23:15.805
I'm thinking we sort of have this idea that, okay, if something happens in the brain in a really bad state in addiction, you know, really serious substance addiction, then the things that we see that we kind of analogize to addiction, like they're not as bad behaviors, but they're kind of bad.
00:23:15.805 --> 00:23:16.355
You know?
00:23:16.355 --> 00:23:19.484
Like, I'm not, I'm not able to pull myself out of the video game.
00:23:19.484 --> 00:23:28.845
We see it as kind of like a linear, well, what, what I'm experiencing must just be like step A, and then addiction to cocaine is step D.
00:23:28.845 --> 00:23:30.944
You know, it's like a linear process.
00:23:30.944 --> 00:23:35.765
So I'm just experiencing like a toy version of what's happening in addiction.
00:23:35.765 --> 00:23:43.914
And I wonder if that's actually true, because I think that might be like a fallacious way of thinking about the neuroscience of your brain.
00:23:43.914 --> 00:23:53.474
Like, there might actually be tipping points or thresholds or even like sort of similar looking behaviors could be driven by completely different mechanisms.
00:23:53.474 --> 00:23:55.384
Is that making sense to you?
00:23:55.384 --> 00:23:58.005
'Cause I, I feel like I see this in my tech circles.
00:23:58.005 --> 00:24:00.164
People are trying to reach for these...
00:24:00.164 --> 00:24:17.234
There are certain things we know about the brain and our bodies that have only been studied in very extreme cases, like addiction, and then they're saying, "Yeah, well, okay, I'm gonna just pull that into my experience with having a bad habit, and I'm gonna say that it's the same mechanism secretly driving it." And I'm not...
00:24:17.234 --> 00:24:19.825
I'm like, "Hmm, do we actually have the evidence for that?"
00:24:20.414 --> 00:24:23.345
Yeah, I think that's a really, really good question.
00:24:23.345 --> 00:24:37.115
So I think the big difference here is like, yes, you get a little burst of dopamine in response to, like, doing something good as a reinforcement signal, and that happens when you play video games, it happens when you listen to music.
00:24:37.115 --> 00:24:40.025
It probably happens when you're, like, talking with friends, right?
00:24:40.025 --> 00:24:45.295
Like, anything that feels good gets a little bit of dopamine in your brain, as well as opioids and all the other stuff.
00:24:45.295 --> 00:25:02.394
But the thing that's really different and categorically different, like a phase change, in something like cocaine dependence, is your baseline dopamine and your need for dopamine reinforcement So it's no longer just the little burst that changes.
00:25:02.394 --> 00:25:05.355
It's like now your system needs more in order
00:25:05.375 --> 00:25:06.545
That feels different.
00:25:06.545 --> 00:25:10.174
That feels like a different thing than just the hit itself.
00:25:10.174 --> 00:25:33.974
And, like, I'm thinking about how both you and I really like to try to pull things back to the systems level, and I'm thinking about things like, you know, in learning science, we talk about, yeah, everybody gets distracted or everybody has some inefficient strategies, but some people have regulation come in and bring them back into balance, and some people fail to enact that process.
00:25:33.974 --> 00:25:37.345
And I'm wondering about that with some of these neurotransmitters.
00:25:37.345 --> 00:25:47.065
If you're just talking about a single thing in the brain in the abstract, you're not talking about, like, all the other things that might come on board to, modulate it or bring it into balance.
00:25:47.065 --> 00:26:00.045
And, like, you could say, "Okay, the hit happens," but, like, there's a big difference between someone who-- and then your brain resets back to its homeostasis as it should versus someone who doesn't.
00:26:00.045 --> 00:26:01.875
Those are very different experiences
00:26:02.121 --> 00:26:02.480
Yeah.
00:26:02.480 --> 00:26:04.941
No, I absolutely, this is such a good point.
00:26:04.941 --> 00:26:09.711
And again, it comes back to this idea that, like, we're not just, like, a bad feedback loop, you know?
00:26:09.711 --> 00:26:12.691
Like, you have other mechanisms in your brain
00:26:12.984 --> 00:26:13.904
Other feedback loops.
00:26:14.181 --> 00:26:17.260
other feedback l- like sure, it's, it's a lot of feedback loops.
00:26:17.260 --> 00:26:18.921
They're all happening all at once.
00:26:18.921 --> 00:26:19.770
It's very dynamic.
00:26:19.770 --> 00:26:20.810
It's very nonlinear.
00:26:20.810 --> 00:26:22.260
This is the brain, right?
00:26:22.260 --> 00:26:26.590
It is not as simple as, like, more dopamine, more reward, more good, I do more.
00:26:26.590 --> 00:26:26.820
Like,
00:26:26.977 --> 00:26:32.777
And now we get to our relationship long conversation about determinism and reductionism
00:26:33.371 --> 00:26:33.560
Oh,
00:26:33.626 --> 00:26:37.116
whether there's, like, a consciousness that emerges from all of these loops.
00:26:37.116 --> 00:26:46.307
But I lo- I, I love this because I think it's just so gr- one thing I try to do whenever I work with teams in the real world is I say, "Okay.
00:26:46.307 --> 00:26:46.747
All right.
00:26:46.747 --> 00:26:50.317
We've identified a bad loop." I mean, my s- mine's not biology.
00:26:50.317 --> 00:26:55.936
It's like you have a, a jerk pushing code in a way that you think is really unkind to you.
00:26:55.936 --> 00:26:59.277
And I always ask, "What happens next?
00:26:59.277 --> 00:27:00.826
What happens next?
00:27:00.826 --> 00:27:04.257
Do you talk to that person, or do you just ignore it?
00:27:04.257 --> 00:27:06.807
Do you passive aggressively make a bad pull request back?
00:27:06.807 --> 00:27:16.987
Like, what do you, what happens next?" And I think that the what happens next question is really, really helpful because it, it takes us out of this, like, cherry-picking explanations and into, like, the larger system
00:27:17.482 --> 00:27:18.053
I love that.
00:27:18.053 --> 00:27:28.603
And I would ask the same thing of people that are kind of like, "Okay, I feel addicted to my phone," or, "I feel addicted to this video game." I'm like, "I'm gonna get off this call and go play Hades." You know?
00:27:28.603 --> 00:27:31.292
Okay, and then your question is, like, what happens next?
00:27:31.292 --> 00:27:36.393
Like, you observe that, that habit that you've formed, right, that impulse.
00:27:36.393 --> 00:27:37.303
What do you do next?
00:27:37.303 --> 00:27:43.242
Do you, like, step out and you're like, "Okay, a better thing for me would be, like, taking a walk or calling a friend"?
00:27:43.242 --> 00:27:46.232
You know, like, is there a way that you interrupt the signal?
00:27:46.232 --> 00:27:49.643
And I don't think we need to call it dopamine fasting.
00:27:49.643 --> 00:27:57.262
Like, you know, and, and if you wanna go so extreme with that where you're, like, never gonna look at anything that causes dopamine...
00:27:57.262 --> 00:28:08.182
I mean, first of all, that's impossible because again, like, if you saw, like, a nice color, your brain would probably release a little bit of dopamine, so, like, good luck trying to avoid the dopamine all entirely.
00:28:08.182 --> 00:28:12.613
But also, you know, like, I just feel like you should call it what it is.
00:28:12.613 --> 00:28:19.252
Like, if you want puritanism, like, just have puritanism and don't use dopamine to make an argument for that.
00:28:19.648 --> 00:28:29.348
You're, you're trying to reach for a brain-based explanation for why you think people shouldn't have fun and, you know, because you feel like people can't argue with it or something
00:28:30.106 --> 00:28:34.047
Yeah, I just, it's like, don't get the brain involved.
00:28:34.047 --> 00:28:43.527
It's, it's just so much more it's, it's just, like, so much more complicated than, than just a little burst of dopamine or a dopamine hit
00:28:44.171 --> 00:28:44.770
Hmm.
00:28:45.270 --> 00:28:53.451
The people need to know if this debate about determinism and such instigated subsequent dates that kept the flame going.
00:28:53.451 --> 00:28:54.310
Please expand
00:28:56.224 --> 00:28:57.305
Defi- definitely.
00:28:57.305 --> 00:28:58.085
Definitely.
00:28:58.085 --> 00:29:02.664
Like I can't resist an argument that I find interesting.
00:29:04.567 --> 00:29:11.416
Yeah, I would say we have this, like, argument maybe once every six months or something, like recurring.
00:29:11.416 --> 00:29:16.737
And actually, I remember one, we were actually in, San Antonio and...
00:29:16.737 --> 00:29:17.666
Do you remember this, babe?
00:29:17.666 --> 00:29:18.196
Like, we were in
00:29:18.353 --> 00:29:18.633
Oh yeah.
00:29:18.633 --> 00:29:19.853
Oh yeah, of course I remember this
00:29:19.926 --> 00:29:21.396
probably the big first one
00:29:21.982 --> 00:29:33.553
the big one and, and I was shopping for a wedding dress at the time and then came back to the hotel room and I was like, "Wait, can I marry someone who is a reductionist?"
00:29:34.323 --> 00:29:37.292
Yeah, and it was, it was really intense actually.
00:29:37.292 --> 00:29:44.932
And I was like, "Yeah, sure, I'm, I'm a reductionist." Like, I sort of like said it in a passing way like it wasn't gonna be a big deal, and Cat was like, "I'm sorry, what?"
00:29:45.182 --> 00:29:47.532
To be clear, Ashley's my life partner forever.
00:29:47.532 --> 00:29:49.032
I was not questioning the relationship.
00:29:49.032 --> 00:29:54.303
I was more trying to figure out how am I going to find my path to understanding this?
00:29:54.303 --> 00:30:00.083
This has been like a long-running conversation in our relationship, yeah.
00:30:00.163 --> 00:30:04.692
still bought a wedding dress on that trip, so I'm gonna say it wasn't devastating.
00:30:05.535 --> 00:30:17.095
Well, I think the, the fact is we talked about phenomenology on our first date, and I was like, "Oh, I think I could spend some time with this person because she knows Merleau-Ponty." And so that's
00:30:17.136 --> 00:30:19.406
I hung out with a lot of philosophy grad students at the time.
00:30:20.545 --> 00:30:25.644
and you pulled it out on the first date, and that was a real green flag, and there were, like, some red flags.
00:30:25.644 --> 00:30:29.734
Like, I really, really don't like sketchy little dive bars.
00:30:29.734 --> 00:30:36.355
I, like, don't drink that much, and Ashley took me to, like, a sketchy little dive bar, and she was like, "Oh, let's get some beer." And
00:30:36.517 --> 00:30:38.126
I think I would call it a dive bar.
00:30:38.126 --> 00:30:40.807
They had a really good selection of craft beers
00:30:41.394 --> 00:30:41.904
right, right.
00:30:41.904 --> 00:30:49.954
I wouldn't have even known the distinction back then, and I'm, like, showing up femme to the max, like heels, like that's who I am.
00:30:49.954 --> 00:30:54.684
And Ashley, at the time, 90% of her wardrobe was brewery T-shirts.
00:30:55.825 --> 00:30:55.964
Yeah.
00:30:55.964 --> 00:30:57.474
That's, that's true.
00:30:58.125 --> 00:30:58.535
But, you
00:30:58.545 --> 00:31:07.855
I was wearing a gray T-shirt, and I actually met up with some friends afterwards, and they were like, "Wait, you just had a first date and you were wearing that?" Brutal.
00:31:07.855 --> 00:31:09.714
Absolutely brutal.
00:31:09.714 --> 00:31:09.914
I
00:31:10.045 --> 00:31:11.095
We were all going through a
00:31:11.154 --> 00:31:13.005
tell them how it's going.
00:31:13.855 --> 00:31:14.474
That's right.
00:31:14.474 --> 00:31:21.244
But then you were like, "Oh, Merleau-Ponty and the phenomenologists, and, like, what kind of philosophy, you know, are you interested in?" I was like, "Okay.
00:31:21.244 --> 00:31:22.095
All right.
00:31:22.095 --> 00:31:22.785
Let's talk
00:31:23.250 --> 00:31:35.020
And then, like, actually just last week we were at a park and somehow got to talking about reductionism again, and finally realized maybe Cat had a different idea of reductionism in her head.
00:31:35.020 --> 00:31:39.141
Like, in my mind, it was like I'm a biological reductionist, which is
00:31:39.192 --> 00:31:43.843
I got a big, I got a dopamine hit because I was like, unexpected topic in this
00:31:44.371 --> 00:31:45.050
Unexpected
00:31:45.292 --> 00:31:48.373
unexpected finding we have to do.
00:31:48.373 --> 00:31:53.772
Yeah, I got really reinforced, um, by that conversation to like ask you more questions.
00:31:54.267 --> 00:32:01.076
And then just this morning you sent me some survey of neuroscientists that, like, is about whether they believe in free will or not.
00:32:02.042 --> 00:32:02.623
Yeah.
00:32:02.623 --> 00:32:03.163
Yeah.
00:32:03.163 --> 00:32:04.313
It's all delightful.
00:32:04.313 --> 00:32:06.073
It's all delightful for me to talk about.
00:32:06.073 --> 00:32:08.833
I mean, I think that, like, I had to pull it back to the podcast.
00:32:08.833 --> 00:32:14.752
Like, understanding what we're experiencing is hard, you know?
00:32:14.752 --> 00:32:17.643
And I think it's hard and it's scary.
00:32:17.643 --> 00:32:21.823
It's scary to watch yourself do things that you don't feel like you actually wanna do.
00:32:21.823 --> 00:32:27.893
You're like, "Why am I doing this?" And, and yet part of me wants to, and I don't know where that part comes from.
00:32:27.893 --> 00:32:28.022
I
00:32:28.310 --> 00:32:28.641
Hmm
00:32:29.232 --> 00:32:35.353
it's this huge stack of things like our habits and then our I mean, chemistry's involved, right?
00:32:35.353 --> 00:32:37.873
Like, your physiology's involved, so.
00:32:37.873 --> 00:32:53.202
But I, I love regulation because I think it is such a helpful piece to bring in to say, "Look, you are also regulating this all the ti- you're go- you are actually When you move your body, that seems to modu- that probably changes what's happening with dopamine.
00:32:53.202 --> 00:32:57.823
Like, you're not a rat in a cage, you know?
00:32:57.823 --> 00:33:02.833
Even rats in the real world are not represented by their caged behaviors.
00:33:03.184 --> 00:33:03.644
Yeah.
00:33:03.644 --> 00:33:12.714
I have, like, a lot of compassion for our need to understand what we're going through and, as you said, kind of understand our compulsions.
00:33:12.714 --> 00:33:13.535
Like, absolutely.
00:33:13.535 --> 00:33:30.184
I mean, this feels like the fundamental human pursuit, like, understanding ourselves, and, and I want that a lot, but I, but I don't want it in the way that I think doesn't really take into account how complex it is in a really beautiful way.
00:33:30.184 --> 00:33:40.105
And, and I also don't want it in a way that takes what we want and our own abilities to regulate ourselves out of the picture.
00:33:40.105 --> 00:33:47.674
You know, I'm not ready to say, "Oh man, my dopamine sucks, and this is the thing that evolution has given me that I have no control over." Like, I just...
00:33:47.674 --> 00:33:52.345
That, to me, feels like the most pessimistic version of the story
00:33:53.025 --> 00:33:53.605
Yeah.
00:33:53.605 --> 00:34:00.234
So now after going on this journey, I have a last question for you, which is, you know, what, what do we not know about dopamine?
00:34:00.234 --> 00:34:01.625
Like, what is a mystery?
00:34:01.625 --> 00:34:03.954
Like, what are scientists struggling to understand?
00:34:03.954 --> 00:34:07.545
Like, what are kind of some big open questions about dopamine?
00:34:08.817 --> 00:34:08.956
Hmm.
00:34:08.956 --> 00:34:10.806
Yeah, that's a great question.
00:34:10.806 --> 00:34:13.586
There are-- I've said that's a great question so much.
00:34:13.586 --> 00:34:14.896
I do that when I'm teaching.
00:34:14.896 --> 00:34:15.297
I'm sorry.
00:34:16.097 --> 00:34:17.577
It's very professorial of
00:34:17.737 --> 00:34:17.996
yeah.
00:34:17.996 --> 00:34:20.617
Wow.
00:34:20.617 --> 00:34:26.297
Um, I think there's, I think there's a couple things.
00:34:26.297 --> 00:34:27.297
I'll name two.
00:34:27.297 --> 00:34:31.106
One is, as I said, it's really hard to study dopamine in humans.
00:34:31.106 --> 00:34:32.157
We have PET scanning.
00:34:32.157 --> 00:34:43.106
We can also do functional MRI, and that gives us insight into areas of the brain that signal with dopamine, but doesn't directly tell us if dopamine is the signal.
00:34:43.106 --> 00:34:52.396
Um, so we have these limited ways to study dopamine in humans, but we have actually a lot more work in non-human animals.
00:34:52.396 --> 00:35:03.416
Like, the initial experiment about reinforcement learning was in primates, was in monkeys, non-human primates, which I know you think is really funny that I say.
00:35:03.416 --> 00:35:07.617
Um, but that's, that's how we talk about it, non-human primates, because we're primates.
00:35:08.327 --> 00:35:12.916
Part of this episode is just learning how neuroscientists talk, which was also part of our early relationship.
00:35:12.916 --> 00:35:18.327
Like, when they say something like decision-making they don't mean what we mean when we say decision-making.
00:35:18.327 --> 00:35:23.436
They're like, "Oh, these little circuits and all th-..." It's just so interesting.
00:35:23.436 --> 00:35:25.947
It's like, ah, we need a translation layer
00:35:27.244 --> 00:35:27.625
Yeah.
00:35:27.625 --> 00:35:28.264
Right.
00:35:28.264 --> 00:35:34.614
So, so I think, the first big thing is taking what we've learned in those animals and applying them to humans.
00:35:34.614 --> 00:35:48.065
And we have a lot of theories both from animal research and computation about, like, the precise kinds of computations that might be happening in different neural circuits that we don't know if they happen in humans because it's very hard to study in humans.
00:35:48.065 --> 00:35:50.735
We may never have some of those answers.
00:35:50.735 --> 00:36:05.355
Um, the best we've been able to get to, like, let's say single cell explanations of what dopamine is doing are the times when we have patients that actually have electrodes already implanted for something like Parkinson's disease.
00:36:05.355 --> 00:36:10.695
So one of the ways that we treat Parkinson's, in addition to giving dopamine, is stimulating dopamine areas
00:36:11.219 --> 00:36:11.679
Right.
00:36:11.679 --> 00:36:17.748
So we can take advantage of some of these extreme situations because it gives us access to a form of data collection that...
00:36:17.748 --> 00:36:24.219
But that's a very specific, that's a very small, specific you know, not randomly selected group of
00:36:24.503 --> 00:36:25.353
Yeah, totally.
00:36:25.353 --> 00:36:28.233
Right, and then you have to ask, well, this is a Parkinson's brain.
00:36:28.233 --> 00:36:32.472
Does it actually signal in the same way that a normal, quote-unquote, brain does?
00:36:32.501 --> 00:36:38.550
this is so interesting though because I, I think I didn't fully realize why you always see people talking about animals.
00:36:38.550 --> 00:36:53.380
Like, people are like, "Coding is, with AI is bad because look at what rats do." And I've always like, "Wait, you know, there actually is a, not enough human work on dopamine," so that's why people are pulling from these animal studies.
00:36:53.380 --> 00:37:11.061
And I think that from a stereotype point of view, that probably makes us even more think, you know, "Oh my gosh, am I just, I'm just the human primate." And that's kind of a scary thought for a lot of people still who aren't used to you know, understanding how brain evidence often comes from animal models and things like that.
00:37:11.061 --> 00:37:16.291
And so you hear these stories of, like, animal studies, and it just feels very scary.
00:37:16.291 --> 00:37:19.820
It feels like determinism that you can't escape.
00:37:19.820 --> 00:37:20.411
Hmm.
00:37:20.434 --> 00:37:21.105
Yeah, totally.
00:37:21.105 --> 00:37:23.224
And animal models are really useful.
00:37:23.224 --> 00:37:26.644
They are how we understand a lot of what the brain does.
00:37:26.644 --> 00:37:32.184
But at the end of the day, if you haven't seen it in a human, we don't know for sure that that's how it works in humans.
00:37:32.184 --> 00:37:34.815
So I think that's, like, gap number one right now.
00:37:34.815 --> 00:37:50.074
Um, gap number two, I think, is understanding, the different roles of dopamine and the different kinds of cells in the brain, because there's actually different kinds of dopamine neurons, not only in different areas of the brain, but even in a single area of the brain, there's different kinds.
00:37:50.074 --> 00:38:03.494
And if you're thinking of, like, you know, the logic on a computer chip or something, and you think about every neuron is talking to, you know, a few hundred other neurons, let's say, the identity of that single neuron matters tremendously.
00:38:03.494 --> 00:38:05.235
They're not all doing the same thing.
00:38:05.235 --> 00:38:06.905
They can make different computations.
00:38:06.905 --> 00:38:19.434
So I just think, like, ultimately, and this is kind of my bias showing as someone who likes to think about single neurons and not, blobs of brain activity, but ultimately, like, the answer comes from single neurons
00:38:19.849 --> 00:38:21.809
Wait, I think I need you to, like, explain this a
00:38:22.592 --> 00:38:23.253
Oh, no.
00:38:23.579 --> 00:38:24.449
f- I'm sorry.
00:38:24.449 --> 00:38:30.248
For someone who's not a neuroscientist, like, what do you mean, like, the identity of the single neuron?
00:38:30.248 --> 00:38:34.619
Or can you, can you, like, teach me a little bit more what you
00:38:34.762 --> 00:38:35.253
Sure.
00:38:35.253 --> 00:38:40.793
I mean, there are different ways we define cell types in the brain.
00:38:40.793 --> 00:38:48.063
We could do a whole episode on this if you want, but, we can define cell types by the other brain regions they talk to.
00:38:48.063 --> 00:38:59.233
And so, for example, there might be a cell in the middle of the brain that talks to the cortex and delivers dopamine to the cortex, and that's one sort of signal.
00:38:59.233 --> 00:39:07.773
There could be a cell in that same brain area that talks to another part of the brain, maybe a, quote-unquote, other reward part of the brain, like the nucleus accumbens.
00:39:07.773 --> 00:39:10.952
That's a different signal than the one going to the cortex.
00:39:10.952 --> 00:39:14.773
So yeah, we define neurons based on who they talk to.
00:39:14.773 --> 00:39:17.663
We also define them based on who they get input from.
00:39:17.663 --> 00:39:21.472
Every neuron is an input-output system, and so it's getting different forms of input.
00:39:21.472 --> 00:39:28.742
Um, and then finally, there's other really interesting things, like there's some dopamine neurons that are kinda constantly firing.
00:39:28.742 --> 00:39:30.682
Like, they're just like, doo, doo, doo, doo, doo.
00:39:30.682 --> 00:39:32.302
We call those tonic firing.
00:39:32.302 --> 00:39:34.813
And then there's neurons that do the bursty thing.
00:39:34.813 --> 00:39:36.382
Yeah, exactly.
00:39:36.382 --> 00:39:37.182
Exactly.
00:39:37.740 --> 00:39:42.320
so this is complicating it 'cause you're like, there's really different forms of activity.
00:39:42.320 --> 00:39:47.731
There's different dopamine processes, even if it's the same category of neurotransmitter.
00:39:47.731 --> 00:39:51.641
What's actually happening with it and on what timeframe is actually very different.
00:39:52.179 --> 00:39:56.798
yeah, neurotransmitters are probably not the way to actually divvy up brain activity
00:39:57.043 --> 00:39:58.932
Yeah, it's just an old-fashioned way
00:39:59.411 --> 00:39:59.811
Yeah.
00:39:59.811 --> 00:40:10.760
They're just like, i- in our world, electricity flows via electrons, and it's like, okay, maybe in a different world there could be 10 different kinds of electrons.
00:40:10.760 --> 00:40:15.021
You'd have like, you know, electron, dopa electron, serotonin electron.
00:40:15.021 --> 00:40:23.920
At the end of the day, they're just the signals that are getting passed, and it's not the signal itself that matters, it's where it's being sent and how and, like, to whom.
00:40:23.920 --> 00:40:33.271
So different neurons use the same neurotransmitter for different kinds of signals, and I think this is actually kinda coming back to big picture, like what is dopamine doing?
00:40:33.271 --> 00:40:35.130
It's actually just context dependent.
00:40:35.130 --> 00:40:40.860
It depends on what neuron is releasing it, and on what timing, and where in the brain.
00:40:41.581 --> 00:40:41.780
It's
00:40:41.780 --> 00:40:43.900
not like we can say dopamine does one thing.
00:40:44.523 --> 00:40:46.382
Seems like we need systems neuroscience
00:40:47.306 --> 00:40:53.146
Yeah, we need you know, better experiments teasing apart this stuff, which people are doing, right?
00:40:53.146 --> 00:40:58.547
But it's, it's tough and it's a slow-moving process but in the meantime, don't blame dopamine for everything
00:00:00.843 --> 00:00:00.914
Dopamine.
00:00:00.914 --> 00:00:02.604
You've probably heard of it.
00:00:02.604 --> 00:00:05.043
I've come across the trend of the dopamine detox.
00:00:05.043 --> 00:00:09.683
What you're doing is chasing the most refined dopamine loop that software has ever produced.
00:00:09.683 --> 00:00:11.933
Today we are going to talk all about dopamine.
00:00:11.933 --> 00:00:15.903
Porn addiction is very much about dopamine.
00:00:15.903 --> 00:00:19.664
Three natural ways to boost your baseline dopamine levels.
00:00:19.664 --> 00:00:21.963
And you see very little dopamine transmission.
00:00:21.963 --> 00:00:24.513
They are in a chronic dopamine deficit state.
00:00:24.513 --> 00:00:24.583
Dopamine.
00:00:24.583 --> 00:00:26.774
I know it's just dopamine.
00:00:26.774 --> 00:00:27.853
Dopamine.
00:00:27.853 --> 00:00:30.794
But it feels so real to me.
00:00:30.794 --> 00:00:31.954
Dopamine.
00:00:31.954 --> 00:00:33.764
I know it's just dopamine.
00:00:33.764 --> 00:00:35.893
But is it?
00:00:37.716 --> 00:00:38.396
I made that for you.
00:00:38.802 --> 00:00:41.222
Was that you doing the Robyn cover?
00:00:50.808 --> 00:00:53.018
That was you secretly auto-tuning yesterday?
00:00:53.936 --> 00:00:57.926
Uh, yeah, you left for about an hour and I became Robyn
00:00:58.478 --> 00:00:59.418
That's incredible.
00:00:59.418 --> 00:01:10.281
I'm so happy about this it seems like dopamine does a lot a lot to us, if not like sociologically, if not biologically.
00:01:10.906 --> 00:01:13.947
I just felt like, in, just in those clips alone, right?
00:01:13.947 --> 00:01:15.057
It's a good thing, it's a bad thing.
00:01:15.057 --> 00:01:16.856
You should fast, you should try to increase it.
00:01:16.856 --> 00:01:18.807
And like, what is the real story here?
00:01:18.807 --> 00:01:20.897
What should we actually know about dopamine?
00:01:20.897 --> 00:01:23.266
What is it actually doing in our brains?
00:01:23.266 --> 00:01:32.677
And like, how much do we actually know versus how much is this sort of like conversation about it and where we're just plugging in dopamine when we really mean something else?
00:01:33.266 --> 00:01:33.626
Hmm.
00:01:33.626 --> 00:01:48.427
Yeah, my main impression about this whole thing is, I mean, my level of knowledge of this is, like, maybe a psychology 101 undergrad class where there was a box that said dopamine, and there was, like, an arrow that pointed to, like, reward.
00:01:48.427 --> 00:01:54.296
And that's my level, and you hear this phrase everywhere.
00:01:54.296 --> 00:02:00.427
I've certainly seen it everywhere in discussions about AI and coding, but I also saw it way before that.
00:02:00.427 --> 00:02:04.716
Like, I saw it with, discussions about should kids use social media?
00:02:04.716 --> 00:02:06.376
What is the internet doing to us?
00:02:06.376 --> 00:02:12.037
Like, kind of plug in the technology of the day, and there was a dopamine discussion for the last five years or something.
00:02:12.037 --> 00:02:13.917
So I'd love to hear your take.
00:02:14.305 --> 00:02:16.224
Dopamine is one of these scapegoats.
00:02:16.224 --> 00:02:26.014
Like, whenever we're upset about something, we're like, "Yeah, it's dopamine." Like, it's, it's smartphones, it's, like, AI, it's whatever you're upset about in society.
00:02:26.014 --> 00:02:27.724
Well, it's because we're fucking up our dopamine.
00:02:27.724 --> 00:02:33.724
And I feel like in so much of this conversation, dopamine has been wronged, you know?
00:02:33.724 --> 00:02:37.284
And like, and so in some ways, I'm here today in defense of dopamine.
00:02:37.284 --> 00:02:38.564
It's not a bad thing.
00:02:38.564 --> 00:02:39.965
It's actually a necessary thing.
00:02:39.965 --> 00:02:45.264
We're gonna talk about some of the things it does in your brain that are non-negotiable.
00:02:45.264 --> 00:02:46.134
Like, you need it.
00:02:46.134 --> 00:02:48.205
I'm sorry, but you can't dopamine fast.
00:02:48.205 --> 00:02:49.564
Like, you, you kinda need it.
00:02:49.564 --> 00:03:01.544
Um, and I think one really interesting thing to me is that even though dopamine right now in the current cultural zeitgeist is the villain, this actually hasn't always been the case.
00:03:01.544 --> 00:03:09.074
In preparing for this episode, I revisited this piece that I love by, um, computational neuroscientist Mark Humphries.
00:03:09.074 --> 00:03:10.574
He's over in the UK.
00:03:10.574 --> 00:03:14.074
He wrote this piece nine years ago called Crimes Against Dopamine.
00:03:14.074 --> 00:03:18.824
I send it to everybody anytime a conversation about dopamine comes up, basically.
00:03:18.824 --> 00:03:28.865
And I opened it up again, and the funniest thing is that in the intro to his piece, he's actually talking a little bit more about how dopamine at the time is framed as a positive thing.
00:03:28.865 --> 00:03:32.004
Like, it's something you should increase if you wanna get motivated.
00:03:32.004 --> 00:03:36.384
It's an explanation for why we love things, like why we love storytelling, for example.
00:03:36.570 --> 00:03:42.491
Oh, like across society we were saying, "Wow, none of us have enough dopamine," at the time, and now we think we have too much
00:03:42.741 --> 00:03:43.860
Yeah, exactly.
00:03:43.860 --> 00:03:46.221
The conversation around it was, was totally different.
00:03:46.221 --> 00:03:51.191
And again, it's just because it's just become the thing that we point to, or one of the things we point to.
00:03:51.191 --> 00:03:56.330
So I wanted to talk a little bit today about like what is dopamine?
00:03:56.330 --> 00:03:57.591
What does it do?
00:03:57.591 --> 00:04:01.211
You said you had a psychology explanation of it.
00:04:01.211 --> 00:04:04.431
Is there anything else you kind of pull out of your like archives of psychology
00:04:04.860 --> 00:04:08.360
Yeah, I'm gonna have to sit here and represent the person who truly doesn't know anything here.
00:04:08.360 --> 00:04:15.411
Um, this is just absolutely not a world that I know much about in terms of neurotransmitters, chemicals in the body.
00:04:15.411 --> 00:04:16.880
I'll sit here and be the audience.
00:04:16.880 --> 00:04:20.380
Like, I know we have chemicals in our body.
00:04:20.380 --> 00:04:24.471
I know that they get modulated by various things.
00:04:24.471 --> 00:04:29.740
Um, you know, maybe the biggest thing I feel familiar with is, like, antidepressants, right?
00:04:29.740 --> 00:04:33.100
So sometimes you end up not having enough of something.
00:04:33.100 --> 00:04:35.500
Um, I know about addiction.
00:04:35.500 --> 00:04:43.670
I know that there are biochemical, very, like, in your body physiological things that happen to people when they are addicted to things.
00:04:43.670 --> 00:04:47.240
Um, I know that that's scary.
00:04:47.240 --> 00:04:52.300
It's scary to imagine that you can get pulled into behaviors like that.
00:04:52.300 --> 00:04:57.380
Um, I wonder about things like the gut biome.
00:04:57.380 --> 00:05:09.951
I wonder about things like, uh, you know, we're increasingly talking about, oh, maybe your, your diet changes your s- I, I know a lot more about serotonin than I know about dopamine, so you know, serotonin's in your gut, right?
00:05:09.951 --> 00:05:10.800
There's a lot of
00:05:10.817 --> 00:05:11.096
Mm-hmm.
00:05:11.096 --> 00:05:11.786
So
00:05:11.821 --> 00:05:13.221
confusing things out there.
00:05:13.221 --> 00:05:14.281
Yeah, well, see?
00:05:14.281 --> 00:05:15.050
There you go.
00:05:15.050 --> 00:05:27.630
Everything is everywhere, and I start, I start, I start, yeah, all at once, and I start to wonder about things like, um, do, does the stuff I do have a really targeted effect?
00:05:27.630 --> 00:05:33.211
Like, do some- does the food I eat impact the, the dopamine in my gut but not in my brain?
00:05:33.211 --> 00:05:33.610
Or what...
00:05:33.610 --> 00:05:36.141
You know, do they have to be at different levels?
00:05:36.141 --> 00:05:46.641
Are people right about this idea that you could get into, like, a deficit or a state that's bad where you're not getting the right feedback, you know?
00:05:46.641 --> 00:05:53.920
From the psychology point of view, I also know a lot about self-regulation, so I know about the kinda psychology level of this.
00:05:53.920 --> 00:05:56.170
It is hard for people to regulate.
00:05:56.170 --> 00:05:59.550
It is hard for people to kinda get out of bad habits.
00:05:59.550 --> 00:06:01.310
So what role does all of this play?
00:06:01.310 --> 00:06:02.930
That's a lot, but
00:06:02.980 --> 00:06:03.540
Yeah.
00:06:03.540 --> 00:06:08.091
No, that, that's a really good sort of set of questions, a really good sort of scan of the landscape.
00:06:08.091 --> 00:06:21.120
And I think, the challenging thing is to many of your questions, like for example, the question of, you know, if I play a video game for an hour, does it increase my gut dopamine or does it increase the dopamine in my, like, reward centers?
00:06:21.120 --> 00:06:30.040
And the answer to that is, like, we don't really entirely know, and as we're gonna get into a little bit later, it's actually really hard to study this directly in humans.
00:06:30.040 --> 00:06:31.271
It's extremely limited.
00:06:31.271 --> 00:06:36.161
You know, but generally speaking, yeah, dopamine, just like serotonin, is a neurotransmitter.
00:06:36.161 --> 00:06:40.281
These are signals, chemical signals that your brain uses to communicate.
00:06:40.281 --> 00:06:45.151
You've got it in multiple parts of your brain and your gut, as we just said.
00:06:45.151 --> 00:06:51.081
Um, so something I learned yesterday as I was doing some research for this is that you actually have dopamine in your eyeball.
00:06:51.081 --> 00:06:54.550
Um, it's helping regulating eye growth.
00:06:54.550 --> 00:06:55.031
Yeah.
00:06:55.031 --> 00:06:55.571
Yeah.
00:06:55.571 --> 00:06:56.401
So it's there.
00:06:56.401 --> 00:07:03.161
Um, another really big place where dopamine plays a role is in this set of brain structures called the basal ganglia.
00:07:03.161 --> 00:07:10.281
This is, a set of brain structures for movement, and this is the area of the brain where dopamine is impacted in Parkinson's disease.
00:07:11.117 --> 00:07:12.478
What happens in Parkinson's disease?
00:07:13.091 --> 00:07:20.552
So in Parkinson's disease, a particular set of neurons in one brain region that release dopamine, um, degrade.
00:07:20.552 --> 00:07:22.252
They start to degenerate.
00:07:22.252 --> 00:07:23.762
We don't entirely know why.
00:07:23.762 --> 00:07:36.151
But yeah, so some of our treatments for Parkinson's, one of the mainline treatments is replacing dopamine, basically giving people either dopamine directly or precursors to dopamine to help increase the amount of dopamine in their brain.
00:07:36.151 --> 00:07:45.581
But then, you know, when people say dopamine, when we're talking about, like, dopamine hits or whatever, they're really talking about the dopamine in your midbrain, which is, like, the core of your brain.
00:07:45.581 --> 00:07:49.172
It's kind of the reward circuitry, the reinforcement learning circuitry.
00:07:49.172 --> 00:07:55.732
It's where we build habits, where we learn to do things through reinforcement or no reinforcement.
00:07:55.781 --> 00:07:57.211
So dopamine hits are real
00:07:58.406 --> 00:08:03.105
Well, there's like a thing that's a dopamine hit, but it's not exactly what people mean when they say dopamine hit.
00:08:03.105 --> 00:08:16.716
And this is the thing that like if you talk to any neuroscientist who studies this stuff, it's the thing that like really rubs them the wrong way about all of this conversation, which is that people equate dopamine with reward, right?
00:08:16.716 --> 00:08:20.196
But really, dopamine is a reinforcement signal.
00:08:20.196 --> 00:08:25.966
It's not the this feels good signal, it's the I want more signal.
00:08:25.966 --> 00:08:28.386
And that's actually a big distinction
00:08:28.636 --> 00:08:30.536
Um, can you unpack that a little bit for me?
00:08:30.536 --> 00:08:32.535
Aren't rewards the thing that reinforces you?
00:08:32.535 --> 00:08:34.196
Like what do you mean by that difference?
00:08:34.618 --> 00:08:35.408
Yeah, totally.
00:08:35.408 --> 00:08:36.538
So it's, it's subtle, right?
00:08:36.538 --> 00:08:42.888
But if we're gonna think about how the brain works and we're gonna try to understand how the brain works, we have to make this distinction.
00:08:42.888 --> 00:08:47.138
And so this brings us to, like, the classic study of dopamine.
00:08:47.138 --> 00:08:58.427
Everything that kicked off our understanding of reinforcement learning, all of the stuff about reinforcement learning and machine learning right now is based on this, 1997 study, by a group of people.
00:08:58.427 --> 00:09:02.648
They actually ultimately got a one million euro brain prize for this work.
00:09:02.648 --> 00:09:04.177
It's, like, really, really big deal.
00:09:04.177 --> 00:09:14.618
And what they did was they were recording from a monkey from those midbrain dopamine neurons that we were talking about, and they're doing, like, a classical conditioning experiment.
00:09:14.618 --> 00:09:19.977
So in a classical conditioning experiment, you're, like, pairing some tone or something with a reward.
00:09:19.977 --> 00:09:28.097
And they notice that when the monkeys get a reward that they are not expecting, there's this, like, little burst of dopamine in their brain.
00:09:28.097 --> 00:09:36.567
It's like, "Ooh!" Like, "What is that?" And I think this is, like, the thing that, you know, this...
00:09:36.567 --> 00:09:38.648
That was better than predicted.
00:09:38.648 --> 00:09:41.268
That's kind of the signal that those neurons are
00:09:41.562 --> 00:09:44.062
Oh, so it's kind of like discovery.
00:09:44.062 --> 00:09:49.881
It's not like, "Oh, I expect this reward," which is maybe like the more compulsive behavior stuff.
00:09:49.881 --> 00:09:58.032
Like, "Oh, I expect this, and I want it, and I can't get out of it." You're more talking about like your brain wants to reward you.
00:09:58.032 --> 00:10:04.802
You go to a new bush and discover a new kind of berry you didn't know about, your brain really wants you to remember about that.
00:10:04.884 --> 00:10:05.344
Totally.
00:10:05.344 --> 00:10:07.053
It's like, "Oh, the bush has the berry.
00:10:07.053 --> 00:10:07.793
Like, how cool.
00:10:07.793 --> 00:10:09.364
Like, that was better than I expected."
00:10:10.131 --> 00:10:16.731
But you go back to the bush, you already know about the berry, it's like a main food supply, you're not gonna get that same reward.
00:10:16.731 --> 00:10:16.812
Is
00:10:16.967 --> 00:10:18.337
When you go back to the berry...
00:10:18.337 --> 00:10:20.018
Yeah, this is, this is-- I love this example.
00:10:20.018 --> 00:10:23.927
So when you go back to the bush, those neurons don't fire when you get the berry.
00:10:23.927 --> 00:10:26.107
They actually fire at the sight of the bush.
00:10:26.107 --> 00:10:30.738
So this is the main finding of this paper, is that the signaling shifts.
00:10:30.738 --> 00:10:42.217
So initially, the signal is, "Wow, that was awesome, better than expected." And then the signal shifts to be more tied to the thing that triggered the reward, which in this case, in your example, is, like, the bush.
00:10:42.217 --> 00:10:44.918
So you see the bush and you're like, "Oh, there it is.
00:10:44.918 --> 00:10:49.888
I'm gonna go back and get it." So it's the signal that reinforces the behavior.
00:10:49.888 --> 00:10:51.427
It, it teaches you.
00:10:51.427 --> 00:10:52.278
It's a learning signal.
00:10:52.278 --> 00:10:57.788
It teaches you to go back to that thing that gave you a better than expected reward.
00:10:58.333 --> 00:10:58.744
Hmm.
00:10:58.744 --> 00:11:05.354
So what does this change about, like, the way that people talk about it in social media or out there in the world?
00:11:05.354 --> 00:11:08.224
Like, what what's the misconception that you keep seeing?
00:11:08.474 --> 00:11:12.783
Well, I think it's just like a sloppy representation of what the brain does.
00:11:12.783 --> 00:11:27.953
Um, you know, I think like this particular point has less of a severe implication for the conversation about it because at the end of the day, what people are ultimately trying to do is they're just trying to like tie it to some brain circuitry.
00:11:27.953 --> 00:11:30.614
And, and in this case, they're just tying it to the wrong thing.
00:11:30.614 --> 00:11:47.754
So even though like dopamine ultimately as you learn things does start to get released as you feel good because it's this conditioning system, it's tied to it ultimately, the actual like signal in the brain that it is is just not that feel-good system.
00:11:47.754 --> 00:11:50.313
That's actually more of like opioids, for example.
00:11:50.313 --> 00:11:58.683
So it's kind of funny we don't say like, "Oh, I got an opioid hit." Like no one says like, "Oh, I got an endogenous opioid hit whenever whenever I like did this particular
00:11:58.734 --> 00:11:59.303
yeah.
00:11:59.303 --> 00:12:00.303
Okay.
00:12:00.303 --> 00:12:00.714
Yeah.
00:12:00.714 --> 00:12:17.144
I'm already taking away the feeling of just kind of like this is a little bit more complicated than like thing happens, I get reward, now I'm trapped, and I can never get outside of that loop because, there's all sorts of other circuits ha- you know, being activated.
00:12:17.144 --> 00:12:36.823
And like one implication that I'm taking from it is if you see a study or a piece of evidence out there that says, "Look, you know, when people did X, like the dopamine increased," or, "When rats pushed a lever, the dopamine increased," that's really not telling you about everything that we experience in our day as we're like making choices about our own behaviors.
00:12:37.268 --> 00:12:46.187
It's like the worst case of biological reductionism where, like, you're, you're reducing this thing that is really complicated, you know.
00:12:46.187 --> 00:12:55.658
As you know, like, habit formation, as you mentioned earlier, self-regulation, there's all of these systems in the brain and the body that are here to, like, help us regulate our behaviors.
00:12:55.658 --> 00:12:56.707
It's not as simple...
00:12:56.707 --> 00:13:03.408
Like, we are, we are not as simple beings as, like, we do a thing and it feels good and we get reinforced for it, and then we keep doing it.
00:13:03.408 --> 00:13:07.327
Like, there's this endless cycle that is feeding back on that kind of behavior.
00:13:07.327 --> 00:13:14.057
Maybe one big takeaway is that this is a kind of negative, pessimistic view of what humans are like.
00:13:14.057 --> 00:13:18.018
We're not this, this simple feedback loop, you know?
00:13:18.018 --> 00:13:22.508
And, and you are also not subject to your own, quote-unquote, "dopamine," you know, or c- call it whatever molecule you want
00:13:25.509 --> 00:13:26.740
So I have a question for you.
00:13:26.740 --> 00:13:34.870
Does this mean that you can engineer your dopamine because of the way that you think about the world and the way that you expect things?
00:13:34.870 --> 00:14:06.830
So like if you change your own expectations of, what you're gonna get Like I'm thinking about my world of, like expectancy value, you know, motivation cycles, and like if you change your expectation of what's gonna happen when you tackle a math problem and you say, "Oh, I'm gonna, I'm gonna actually see the friction as a good thing that's g- giving me a reward, that's telling me I'm working hard, and working hard is good, and I like that, and it's progressing me towards my goals." Like you can deeply change how aversive people find that experience and the meaning they take from it.
00:14:06.830 --> 00:14:08.629
So that's like the psychology level.
00:14:08.629 --> 00:14:10.519
Is it connecting to biology?
00:14:10.519 --> 00:14:14.980
Like is it changing the type of dopamine you're getting in the classroom, you know?
00:14:15.538 --> 00:14:17.398
Okay, so this is a really good question.
00:14:17.398 --> 00:14:23.908
I love that you asked this because I've been thinking a lot about expectancy effects for the book that I'm writing, actually.
00:14:23.908 --> 00:14:32.187
Because, you know, for example, when people get a placebo drug but they still get better, that's largely due to expectancy.
00:14:32.187 --> 00:14:36.977
They expected to get better, and so something must be happening in the brain when they expect to get better.
00:14:36.977 --> 00:14:40.888
And it's probably not mostly dopamine.
00:14:40.888 --> 00:14:45.967
Most of the research points to your internal opioid system.
00:14:45.967 --> 00:14:47.807
We call them the endogenous opioids.
00:14:47.807 --> 00:14:50.988
Uh, most research points to that being really important.
00:14:50.988 --> 00:14:57.378
Dopamine is almost definitely involved at some level because, as I mentioned earlier, it's the learning signal.
00:14:57.378 --> 00:15:00.238
It's the thing that's gonna ultimately reinforce the behavior.
00:15:00.238 --> 00:15:07.557
But expectancy itself probably manifests in the brain a little bit more with opioid signaling.
00:15:07.557 --> 00:15:18.217
That said, when we think about habit formation or even addiction, it is absolutely true that dopamine in the brain is changing.
00:15:18.217 --> 00:15:25.638
I mean, this is one of the biggest findings, and it's mostly people's background tonic dopamine levels.
00:15:25.638 --> 00:15:33.467
It ends up being that you need, a bigger hit in order to get that same feeling, in order to get that same reinforcement.
00:15:33.467 --> 00:15:43.067
So that is something, you know, that I think is worth thinking about, that maybe we have some lever of control over.
00:15:43.067 --> 00:15:51.498
It's not as simple as, oh, you shouldn't over-pleasure yourself because you're gonna, like, screw up your brain, right?
00:15:51.498 --> 00:15:54.697
That's kind of like "Dopamine Nation's" main point, right?
00:15:54.697 --> 00:15:55.097
And it's
00:15:55.340 --> 00:16:00.549
a next question I have, which is like, how much does your body actually keep this in balance?
00:16:00.549 --> 00:16:02.669
And like when should you get worried about it?
00:16:02.669 --> 00:16:07.909
And how, how easily, how easy is it to knock this system off its homeostasis, you know?
00:16:08.351 --> 00:16:09.131
Yeah, and that's,
00:16:09.230 --> 00:16:12.750
Are we all addicted to our phones, or is addiction the wrong metaphor?
00:16:13.782 --> 00:16:21.942
Addiction is like a very, you know, in, in the research, addiction has a very particular definition which people have debated over, right?
00:16:21.942 --> 00:16:27.371
In a simple version of it, it's a behavior that if you don't do, you go through withdrawal.
00:16:27.371 --> 00:16:33.841
So if you don't have withdrawal symptoms from your phone, then you're not addicted to it, at least by that one definition.
00:16:33.961 --> 00:16:34.231
Ooh.
00:16:34.231 --> 00:16:37.392
Can you define, like what are withdrawal symptoms like actually?
00:16:38.443 --> 00:16:44.923
Yeah, withdrawal you could define either behaviorally or, biologically, right?
00:16:44.923 --> 00:16:50.533
You have, like, some negative response to not having the drug or not having the thing, right?
00:16:50.533 --> 00:16:52.403
So it's a hu- it's a hangover,
00:16:52.538 --> 00:16:55.177
But I would say it, it's a very strong negative.
00:16:55.177 --> 00:16:59.957
It's a very strong threshold to meet because you-- it can't just be, "Oh, I miss it.
00:16:59.957 --> 00:17:02.337
Oh, I like doing this." That's just a bad habit.
00:17:02.337 --> 00:17:05.817
Like, I, I like doing this thing and it's a little bit bad for me.
00:17:05.817 --> 00:17:13.807
Like, you wouldn't say that students are addicted to procrastinating, even if they have a longstanding, deeply ingrained habit of doing it.
00:17:13.807 --> 00:17:21.067
It doesn't rise to the level of addiction because a- addiction withdrawal in psychology, in the clinical sense, is, like, very severe.
00:17:21.067 --> 00:17:29.298
It's, like, impacting your daily life functioning, and I don't just mean, like, you were an A student and now you're a C student.
00:17:29.298 --> 00:17:34.278
I mean, like, very y- big, you know, breakdown of relationships kind of stuff.
00:17:34.278 --> 00:17:50.688
And that's something that bothers me kinda out there, is this calling everything addiction, because I actually think addiction's this enormously sensitive, you know, profound problem in the world where we have a lot of people suffering, and there's been a lot of misconception about it.
00:17:50.688 --> 00:18:03.637
There's a great paper that is about, um, how easily we pathologize stuff that comes up with a measure of, like, being addicted to offline friendship, so, like, hanging out with your friends in real life.
00:18:03.637 --> 00:18:15.698
And they take one of these survey measures that people have used to study, quote-unquote, "social media addiction," and they, like, run it with people, but they just change the items to make it be about hanging out with your friends.
00:18:15.698 --> 00:18:26.317
And, and they're like, "Look, people are addicted to having friends, and they have withdrawal if you don't have them." You know, and it's just a way to show basically that these measures are bad.
00:18:26.317 --> 00:18:35.307
They're very badly constructed, and you can kind of create the appearance of addiction if you use these sloppy, broad, vague measures.
00:18:35.307 --> 00:18:40.417
So that's something that, you know, I, I feel like is really interesting to think about.
00:18:40.759 --> 00:18:41.230
Yeah.
00:18:41.230 --> 00:18:49.539
I, it really feels like we pick and choose the things we call addictive versus the things we call, you know, like pleasurable or just good for us or nice to have, you know?
00:18:49.539 --> 00:18:56.440
Obviously, I think very few people would disagree with the idea that friends are good for you, you know?
00:18:56.567 --> 00:19:02.407
Are, are there like things that give us, quote, these dopamine hits that are not, you know, nobody's worried about?
00:19:02.407 --> 00:19:06.067
Like, I would think listening to music or video games.
00:19:06.067 --> 00:19:17.837
I guess, I guess some people talk about video game addiction, but that seems like an activity that we trust that a lot of normal people can do, and we're not, like, regulating it, you know, for addiction, right?
00:19:18.263 --> 00:19:19.223
Yeah, totally.
00:19:19.223 --> 00:19:24.054
I mean, probably when video games first came out, people were like, "Oh my God," like, "The kids are addicted."
00:19:24.480 --> 00:19:25.089
Oh, they were.
00:19:25.089 --> 00:19:25.920
Yeah, absolutely
00:19:26.894 --> 00:19:27.034
I
00:19:27.069 --> 00:19:28.940
there still is that in religious circles
00:19:29.720 --> 00:19:31.490
That's, yeah, no, that's fair.
00:19:31.490 --> 00:19:32.140
But, uh,
00:19:32.221 --> 00:19:37.811
A- as you play Hades, Ashley's playing Hades right now, very intensely playing Hades.
00:19:37.811 --> 00:19:41.241
Are you caught in, like, a dopamine loop playing Hades?
00:19:41.526 --> 00:19:42.226
probably.
00:19:42.226 --> 00:19:45.256
I mean, yeah.
00:19:45.256 --> 00:19:54.905
I mean, I, I think the key thing here is that, like, things that are addictive usually feel good, but not everything that feels good is addictive, right?
00:19:54.905 --> 00:19:56.965
This is, like, something we have to tease apart.
00:19:56.965 --> 00:19:58.486
These things are not the same.
00:19:58.486 --> 00:20:01.336
Um, and, and you could replace dopamine for that, right?
00:20:01.336 --> 00:20:07.556
Like, things that involve dopamine usually feel good, but not everything that involves dopamine is addictive.
00:20:07.556 --> 00:20:09.486
Like, same, same logic.
00:20:09.486 --> 00:20:15.195
So right, your question, do video games invoke dopamine in your brain?
00:20:15.195 --> 00:20:15.996
Absolutely.
00:20:15.996 --> 00:20:43.625
In fact, that's the perfect example because this was probably the first time we ever measured dopamine release in humans, um, and showed that when people were playing this, like, kind of silly video game where they were, like, in a battle tank just driving around, like, collecting stuff, um, they had dopamine release in the same areas of the brain that, you know, signal rewards, so the middle of the brain.
00:20:43.625 --> 00:20:46.465
And, um, that was in 1998, right?
00:20:46.465 --> 00:20:47.125
That's not that long
00:20:47.208 --> 00:20:48.387
how are we measuring that
00:20:49.125 --> 00:20:49.476
Right.
00:20:49.476 --> 00:20:59.915
So yeah, so this is probably one of my biggest pet peeves about the conversation around dopamine, which is it's very hard to measure dopamine in humans.
00:20:59.915 --> 00:21:10.888
So we have kind of one good main way, which is with something called positron emission tomography, and, or PET scanning.
00:21:11.025 --> 00:21:11.924
ah, that's a PET scan,
00:21:12.288 --> 00:21:12.929
Yeah,
00:21:13.204 --> 00:21:14.684
I didn't know what that stood for.
00:21:14.684 --> 00:21:18.414
Positrons, that sounds so 1960s sci-fi.
00:21:18.898 --> 00:21:19.318
Yeah.
00:21:19.318 --> 00:21:19.818
Yeah,
00:21:19.944 --> 00:21:22.065
so w- what does a PET scan do?
00:21:22.608 --> 00:21:30.818
So in a PET scan, you first get injected with something, so it's actually a little bit invasive, which is one of the things that makes this difficult to do.
00:21:30.818 --> 00:21:37.278
Not everybody, even for 25 bucks or an Amazon gift card or whatever, wants to get injected with a radioactive tracer.
00:21:37.278 --> 00:21:38.749
Um, but that's what happens.
00:21:38.749 --> 00:21:41.729
And you use different tracers for different kinds of experiments.
00:21:41.729 --> 00:21:45.058
There's a particular one that people use for dopamine.
00:21:45.058 --> 00:21:55.179
And it's very cool actually, because what this tracer does is it gets into your brain, and then it competes with dopamine for the same sites it would normally bind to.
00:21:55.179 --> 00:22:04.939
So when you have more dopamine release in your own brain, dopamine's gonna out-compete the tracer, and the tracer, um, visibility goes down basically.
00:22:05.163 --> 00:22:06.143
Oh, how neat.
00:22:06.143 --> 00:22:12.593
You're exploiting this mechanism of how these chemicals, like, connect to your brain Wow, that's so cool.
00:22:12.593 --> 00:22:15.843
There's so many little techniques in neuroscience that are, like, so clever like this
00:22:16.270 --> 00:22:16.691
Yeah.
00:22:16.691 --> 00:22:17.441
Yeah, totally.
00:22:17.441 --> 00:22:24.810
So many people have done PET scanning in humans and yeah, like, there's this 1998 study in video games.
00:22:24.810 --> 00:22:29.230
Um, there's a more recent study about music causing dopamine release.
00:22:29.230 --> 00:22:50.760
And then of course, you know, one of the biggest areas this has been used in is the study of drug addiction, And so, um, Nora Volkow, who was,, director of the National Institute of Drug Abuse for many years, she has, like, a whole body of amazing work showing how drugs like cocaine change the dopamine system, and this is largely based on PET scans like the one I just described.
00:22:51.384 --> 00:22:51.884
Yeah.
00:22:51.884 --> 00:22:56.005
This is bringing something up for me, which is kind of this like maybe fallacy.
00:22:56.005 --> 00:22:56.875
You tell me.
00:22:56.875 --> 00:23:15.805
I'm thinking we sort of have this idea that, okay, if something happens in the brain in a really bad state in addiction, you know, really serious substance addiction, then the things that we see that we kind of analogize to addiction, like they're not as bad behaviors, but they're kind of bad.
00:23:15.805 --> 00:23:16.355
You know?
00:23:16.355 --> 00:23:19.484
Like, I'm not, I'm not able to pull myself out of the video game.
00:23:19.484 --> 00:23:28.845
We see it as kind of like a linear, well, what, what I'm experiencing must just be like step A, and then addiction to cocaine is step D.
00:23:28.845 --> 00:23:30.944
You know, it's like a linear process.
00:23:30.944 --> 00:23:35.765
So I'm just experiencing like a toy version of what's happening in addiction.
00:23:35.765 --> 00:23:43.914
And I wonder if that's actually true, because I think that might be like a fallacious way of thinking about the neuroscience of your brain.
00:23:43.914 --> 00:23:53.474
Like, there might actually be tipping points or thresholds or even like sort of similar looking behaviors could be driven by completely different mechanisms.
00:23:53.474 --> 00:23:55.384
Is that making sense to you?
00:23:55.384 --> 00:23:58.005
'Cause I, I feel like I see this in my tech circles.
00:23:58.005 --> 00:24:00.164
People are trying to reach for these...
00:24:00.164 --> 00:24:17.234
There are certain things we know about the brain and our bodies that have only been studied in very extreme cases, like addiction, and then they're saying, "Yeah, well, okay, I'm gonna just pull that into my experience with having a bad habit, and I'm gonna say that it's the same mechanism secretly driving it." And I'm not...
00:24:17.234 --> 00:24:19.825
I'm like, "Hmm, do we actually have the evidence for that?"
00:24:20.414 --> 00:24:23.345
Yeah, I think that's a really, really good question.
00:24:23.345 --> 00:24:37.115
So I think the big difference here is like, yes, you get a little burst of dopamine in response to, like, doing something good as a reinforcement signal, and that happens when you play video games, it happens when you listen to music.
00:24:37.115 --> 00:24:40.025
It probably happens when you're, like, talking with friends, right?
00:24:40.025 --> 00:24:45.295
Like, anything that feels good gets a little bit of dopamine in your brain, as well as opioids and all the other stuff.
00:24:45.295 --> 00:25:02.394
But the thing that's really different and categorically different, like a phase change, in something like cocaine dependence, is your baseline dopamine and your need for dopamine reinforcement So it's no longer just the little burst that changes.
00:25:02.394 --> 00:25:05.355
It's like now your system needs more in order
00:25:05.375 --> 00:25:06.545
That feels different.
00:25:06.545 --> 00:25:10.174
That feels like a different thing than just the hit itself.
00:25:10.174 --> 00:25:33.974
And, like, I'm thinking about how both you and I really like to try to pull things back to the systems level, and I'm thinking about things like, you know, in learning science, we talk about, yeah, everybody gets distracted or everybody has some inefficient strategies, but some people have regulation come in and bring them back into balance, and some people fail to enact that process.
00:25:33.974 --> 00:25:37.345
And I'm wondering about that with some of these neurotransmitters.
00:25:37.345 --> 00:25:47.065
If you're just talking about a single thing in the brain in the abstract, you're not talking about, like, all the other things that might come on board to, modulate it or bring it into balance.
00:25:47.065 --> 00:26:00.045
And, like, you could say, "Okay, the hit happens," but, like, there's a big difference between someone who-- and then your brain resets back to its homeostasis as it should versus someone who doesn't.
00:26:00.045 --> 00:26:01.875
Those are very different experiences
00:26:02.121 --> 00:26:02.480
Yeah.
00:26:02.480 --> 00:26:04.941
No, I absolutely, this is such a good point.
00:26:04.941 --> 00:26:09.711
And again, it comes back to this idea that, like, we're not just, like, a bad feedback loop, you know?
00:26:09.711 --> 00:26:12.691
Like, you have other mechanisms in your brain
00:26:12.984 --> 00:26:13.904
Other feedback loops.
00:26:14.181 --> 00:26:17.260
other feedback l- like sure, it's, it's a lot of feedback loops.
00:26:17.260 --> 00:26:18.921
They're all happening all at once.
00:26:18.921 --> 00:26:19.770
It's very dynamic.
00:26:19.770 --> 00:26:20.810
It's very nonlinear.
00:26:20.810 --> 00:26:22.260
This is the brain, right?
00:26:22.260 --> 00:26:26.590
It is not as simple as, like, more dopamine, more reward, more good, I do more.
00:26:26.590 --> 00:26:26.820
Like,
00:26:26.977 --> 00:26:32.777
And now we get to our relationship long conversation about determinism and reductionism
00:26:33.371 --> 00:26:33.560
Oh,
00:26:33.626 --> 00:26:37.116
whether there's, like, a consciousness that emerges from all of these loops.
00:26:37.116 --> 00:26:46.307
But I lo- I, I love this because I think it's just so gr- one thing I try to do whenever I work with teams in the real world is I say, "Okay.
00:26:46.307 --> 00:26:46.747
All right.
00:26:46.747 --> 00:26:50.317
We've identified a bad loop." I mean, my s- mine's not biology.
00:26:50.317 --> 00:26:55.936
It's like you have a, a jerk pushing code in a way that you think is really unkind to you.
00:26:55.936 --> 00:26:59.277
And I always ask, "What happens next?
00:26:59.277 --> 00:27:00.826
What happens next?
00:27:00.826 --> 00:27:04.257
Do you talk to that person, or do you just ignore it?
00:27:04.257 --> 00:27:06.807
Do you passive aggressively make a bad pull request back?
00:27:06.807 --> 00:27:16.987
Like, what do you, what happens next?" And I think that the what happens next question is really, really helpful because it, it takes us out of this, like, cherry-picking explanations and into, like, the larger system
00:27:17.482 --> 00:27:18.053
I love that.
00:27:18.053 --> 00:27:28.603
And I would ask the same thing of people that are kind of like, "Okay, I feel addicted to my phone," or, "I feel addicted to this video game." I'm like, "I'm gonna get off this call and go play Hades." You know?
00:27:28.603 --> 00:27:31.292
Okay, and then your question is, like, what happens next?
00:27:31.292 --> 00:27:36.393
Like, you observe that, that habit that you've formed, right, that impulse.
00:27:36.393 --> 00:27:37.303
What do you do next?
00:27:37.303 --> 00:27:43.242
Do you, like, step out and you're like, "Okay, a better thing for me would be, like, taking a walk or calling a friend"?
00:27:43.242 --> 00:27:46.232
You know, like, is there a way that you interrupt the signal?
00:27:46.232 --> 00:27:49.643
And I don't think we need to call it dopamine fasting.
00:27:49.643 --> 00:27:57.262
Like, you know, and, and if you wanna go so extreme with that where you're, like, never gonna look at anything that causes dopamine...
00:27:57.262 --> 00:28:08.182
I mean, first of all, that's impossible because again, like, if you saw, like, a nice color, your brain would probably release a little bit of dopamine, so, like, good luck trying to avoid the dopamine all entirely.
00:28:08.182 --> 00:28:12.613
But also, you know, like, I just feel like you should call it what it is.
00:28:12.613 --> 00:28:19.252
Like, if you want puritanism, like, just have puritanism and don't use dopamine to make an argument for that.
00:28:19.648 --> 00:28:29.348
You're, you're trying to reach for a brain-based explanation for why you think people shouldn't have fun and, you know, because you feel like people can't argue with it or something
00:28:30.106 --> 00:28:34.047
Yeah, I just, it's like, don't get the brain involved.
00:28:34.047 --> 00:28:43.527
It's, it's just so much more it's, it's just, like, so much more complicated than, than just a little burst of dopamine or a dopamine hit
00:28:44.171 --> 00:28:44.770
Hmm.
00:28:45.270 --> 00:28:53.451
The people need to know if this debate about determinism and such instigated subsequent dates that kept the flame going.
00:28:53.451 --> 00:28:54.310
Please expand
00:28:56.224 --> 00:28:57.305
Defi- definitely.
00:28:57.305 --> 00:28:58.085
Definitely.
00:28:58.085 --> 00:29:02.664
Like I can't resist an argument that I find interesting.
00:29:04.567 --> 00:29:11.416
Yeah, I would say we have this, like, argument maybe once every six months or something, like recurring.
00:29:11.416 --> 00:29:16.737
And actually, I remember one, we were actually in, San Antonio and...
00:29:16.737 --> 00:29:17.666
Do you remember this, babe?
00:29:17.666 --> 00:29:18.196
Like, we were in
00:29:18.353 --> 00:29:18.633
Oh yeah.
00:29:18.633 --> 00:29:19.853
Oh yeah, of course I remember this
00:29:19.926 --> 00:29:21.396
probably the big first one
00:29:21.982 --> 00:29:33.553
the big one and, and I was shopping for a wedding dress at the time and then came back to the hotel room and I was like, "Wait, can I marry someone who is a reductionist?"
00:29:34.323 --> 00:29:37.292
Yeah, and it was, it was really intense actually.
00:29:37.292 --> 00:29:44.932
And I was like, "Yeah, sure, I'm, I'm a reductionist." Like, I sort of like said it in a passing way like it wasn't gonna be a big deal, and Cat was like, "I'm sorry, what?"
00:29:45.182 --> 00:29:47.532
To be clear, Ashley's my life partner forever.
00:29:47.532 --> 00:29:49.032
I was not questioning the relationship.
00:29:49.032 --> 00:29:54.303
I was more trying to figure out how am I going to find my path to understanding this?
00:29:54.303 --> 00:30:00.083
This has been like a long-running conversation in our relationship, yeah.
00:30:00.163 --> 00:30:04.692
still bought a wedding dress on that trip, so I'm gonna say it wasn't devastating.
00:30:05.535 --> 00:30:17.095
Well, I think the, the fact is we talked about phenomenology on our first date, and I was like, "Oh, I think I could spend some time with this person because she knows Merleau-Ponty." And so that's
00:30:17.136 --> 00:30:19.406
I hung out with a lot of philosophy grad students at the time.
00:30:20.545 --> 00:30:25.644
and you pulled it out on the first date, and that was a real green flag, and there were, like, some red flags.
00:30:25.644 --> 00:30:29.734
Like, I really, really don't like sketchy little dive bars.
00:30:29.734 --> 00:30:36.355
I, like, don't drink that much, and Ashley took me to, like, a sketchy little dive bar, and she was like, "Oh, let's get some beer." And
00:30:36.517 --> 00:30:38.126
I think I would call it a dive bar.
00:30:38.126 --> 00:30:40.807
They had a really good selection of craft beers
00:30:41.394 --> 00:30:41.904
right, right.
00:30:41.904 --> 00:30:49.954
I wouldn't have even known the distinction back then, and I'm, like, showing up femme to the max, like heels, like that's who I am.
00:30:49.954 --> 00:30:54.684
And Ashley, at the time, 90% of her wardrobe was brewery T-shirts.
00:30:55.825 --> 00:30:55.964
Yeah.
00:30:55.964 --> 00:30:57.474
That's, that's true.
00:30:58.125 --> 00:30:58.535
But, you
00:30:58.545 --> 00:31:07.855
I was wearing a gray T-shirt, and I actually met up with some friends afterwards, and they were like, "Wait, you just had a first date and you were wearing that?" Brutal.
00:31:07.855 --> 00:31:09.714
Absolutely brutal.
00:31:09.714 --> 00:31:09.914
I
00:31:10.045 --> 00:31:11.095
We were all going through a
00:31:11.154 --> 00:31:13.005
tell them how it's going.
00:31:13.855 --> 00:31:14.474
That's right.
00:31:14.474 --> 00:31:21.244
But then you were like, "Oh, Merleau-Ponty and the phenomenologists, and, like, what kind of philosophy, you know, are you interested in?" I was like, "Okay.
00:31:21.244 --> 00:31:22.095
All right.
00:31:22.095 --> 00:31:22.785
Let's talk
00:31:23.250 --> 00:31:35.020
And then, like, actually just last week we were at a park and somehow got to talking about reductionism again, and finally realized maybe Cat had a different idea of reductionism in her head.
00:31:35.020 --> 00:31:39.141
Like, in my mind, it was like I'm a biological reductionist, which is
00:31:39.192 --> 00:31:43.843
I got a big, I got a dopamine hit because I was like, unexpected topic in this
00:31:44.371 --> 00:31:45.050
Unexpected
00:31:45.292 --> 00:31:48.373
unexpected finding we have to do.
00:31:48.373 --> 00:31:53.772
Yeah, I got really reinforced, um, by that conversation to like ask you more questions.
00:31:54.267 --> 00:32:01.076
And then just this morning you sent me some survey of neuroscientists that, like, is about whether they believe in free will or not.
00:32:02.042 --> 00:32:02.623
Yeah.
00:32:02.623 --> 00:32:03.163
Yeah.
00:32:03.163 --> 00:32:04.313
It's all delightful.
00:32:04.313 --> 00:32:06.073
It's all delightful for me to talk about.
00:32:06.073 --> 00:32:08.833
I mean, I think that, like, I had to pull it back to the podcast.
00:32:08.833 --> 00:32:14.752
Like, understanding what we're experiencing is hard, you know?
00:32:14.752 --> 00:32:17.643
And I think it's hard and it's scary.
00:32:17.643 --> 00:32:21.823
It's scary to watch yourself do things that you don't feel like you actually wanna do.
00:32:21.823 --> 00:32:27.893
You're like, "Why am I doing this?" And, and yet part of me wants to, and I don't know where that part comes from.
00:32:27.893 --> 00:32:28.022
I
00:32:28.310 --> 00:32:28.641
Hmm
00:32:29.232 --> 00:32:35.353
it's this huge stack of things like our habits and then our I mean, chemistry's involved, right?
00:32:35.353 --> 00:32:37.873
Like, your physiology's involved, so.
00:32:37.873 --> 00:32:53.202
But I, I love regulation because I think it is such a helpful piece to bring in to say, "Look, you are also regulating this all the ti- you're go- you are actually When you move your body, that seems to modu- that probably changes what's happening with dopamine.
00:32:53.202 --> 00:32:57.823
Like, you're not a rat in a cage, you know?
00:32:57.823 --> 00:33:02.833
Even rats in the real world are not represented by their caged behaviors.
00:33:03.184 --> 00:33:03.644
Yeah.
00:33:03.644 --> 00:33:12.714
I have, like, a lot of compassion for our need to understand what we're going through and, as you said, kind of understand our compulsions.
00:33:12.714 --> 00:33:13.535
Like, absolutely.
00:33:13.535 --> 00:33:30.184
I mean, this feels like the fundamental human pursuit, like, understanding ourselves, and, and I want that a lot, but I, but I don't want it in the way that I think doesn't really take into account how complex it is in a really beautiful way.
00:33:30.184 --> 00:33:40.105
And, and I also don't want it in a way that takes what we want and our own abilities to regulate ourselves out of the picture.
00:33:40.105 --> 00:33:47.674
You know, I'm not ready to say, "Oh man, my dopamine sucks, and this is the thing that evolution has given me that I have no control over." Like, I just...
00:33:47.674 --> 00:33:52.345
That, to me, feels like the most pessimistic version of the story
00:33:53.025 --> 00:33:53.605
Yeah.
00:33:53.605 --> 00:34:00.234
So now after going on this journey, I have a last question for you, which is, you know, what, what do we not know about dopamine?
00:34:00.234 --> 00:34:01.625
Like, what is a mystery?
00:34:01.625 --> 00:34:03.954
Like, what are scientists struggling to understand?
00:34:03.954 --> 00:34:07.545
Like, what are kind of some big open questions about dopamine?
00:34:08.817 --> 00:34:08.956
Hmm.
00:34:08.956 --> 00:34:10.806
Yeah, that's a great question.
00:34:10.806 --> 00:34:13.586
There are-- I've said that's a great question so much.
00:34:13.586 --> 00:34:14.896
I do that when I'm teaching.
00:34:14.896 --> 00:34:15.297
I'm sorry.
00:34:16.097 --> 00:34:17.577
It's very professorial of
00:34:17.737 --> 00:34:17.996
yeah.
00:34:17.996 --> 00:34:20.617
Wow.
00:34:20.617 --> 00:34:26.297
Um, I think there's, I think there's a couple things.
00:34:26.297 --> 00:34:27.297
I'll name two.
00:34:27.297 --> 00:34:31.106
One is, as I said, it's really hard to study dopamine in humans.
00:34:31.106 --> 00:34:32.157
We have PET scanning.
00:34:32.157 --> 00:34:43.106
We can also do functional MRI, and that gives us insight into areas of the brain that signal with dopamine, but doesn't directly tell us if dopamine is the signal.
00:34:43.106 --> 00:34:52.396
Um, so we have these limited ways to study dopamine in humans, but we have actually a lot more work in non-human animals.
00:34:52.396 --> 00:35:03.416
Like, the initial experiment about reinforcement learning was in primates, was in monkeys, non-human primates, which I know you think is really funny that I say.
00:35:03.416 --> 00:35:07.617
Um, but that's, that's how we talk about it, non-human primates, because we're primates.
00:35:08.327 --> 00:35:12.916
Part of this episode is just learning how neuroscientists talk, which was also part of our early relationship.
00:35:12.916 --> 00:35:18.327
Like, when they say something like decision-making they don't mean what we mean when we say decision-making.
00:35:18.327 --> 00:35:23.436
They're like, "Oh, these little circuits and all th-..." It's just so interesting.
00:35:23.436 --> 00:35:25.947
It's like, ah, we need a translation layer
00:35:27.244 --> 00:35:27.625
Yeah.
00:35:27.625 --> 00:35:28.264
Right.
00:35:28.264 --> 00:35:34.614
So, so I think, the first big thing is taking what we've learned in those animals and applying them to humans.
00:35:34.614 --> 00:35:48.065
And we have a lot of theories both from animal research and computation about, like, the precise kinds of computations that might be happening in different neural circuits that we don't know if they happen in humans because it's very hard to study in humans.
00:35:48.065 --> 00:35:50.735
We may never have some of those answers.
00:35:50.735 --> 00:36:05.355
Um, the best we've been able to get to, like, let's say single cell explanations of what dopamine is doing are the times when we have patients that actually have electrodes already implanted for something like Parkinson's disease.
00:36:05.355 --> 00:36:10.695
So one of the ways that we treat Parkinson's, in addition to giving dopamine, is stimulating dopamine areas
00:36:11.219 --> 00:36:11.679
Right.
00:36:11.679 --> 00:36:17.748
So we can take advantage of some of these extreme situations because it gives us access to a form of data collection that...
00:36:17.748 --> 00:36:24.219
But that's a very specific, that's a very small, specific you know, not randomly selected group of
00:36:24.503 --> 00:36:25.353
Yeah, totally.
00:36:25.353 --> 00:36:28.233
Right, and then you have to ask, well, this is a Parkinson's brain.
00:36:28.233 --> 00:36:32.472
Does it actually signal in the same way that a normal, quote-unquote, brain does?
00:36:32.501 --> 00:36:38.550
this is so interesting though because I, I think I didn't fully realize why you always see people talking about animals.
00:36:38.550 --> 00:36:53.380
Like, people are like, "Coding is, with AI is bad because look at what rats do." And I've always like, "Wait, you know, there actually is a, not enough human work on dopamine," so that's why people are pulling from these animal studies.
00:36:53.380 --> 00:37:11.061
And I think that from a stereotype point of view, that probably makes us even more think, you know, "Oh my gosh, am I just, I'm just the human primate." And that's kind of a scary thought for a lot of people still who aren't used to you know, understanding how brain evidence often comes from animal models and things like that.
00:37:11.061 --> 00:37:16.291
And so you hear these stories of, like, animal studies, and it just feels very scary.
00:37:16.291 --> 00:37:19.820
It feels like determinism that you can't escape.
00:37:19.820 --> 00:37:20.411
Hmm.
00:37:20.434 --> 00:37:21.105
Yeah, totally.
00:37:21.105 --> 00:37:23.224
And animal models are really useful.
00:37:23.224 --> 00:37:26.644
They are how we understand a lot of what the brain does.
00:37:26.644 --> 00:37:32.184
But at the end of the day, if you haven't seen it in a human, we don't know for sure that that's how it works in humans.
00:37:32.184 --> 00:37:34.815
So I think that's, like, gap number one right now.
00:37:34.815 --> 00:37:50.074
Um, gap number two, I think, is understanding, the different roles of dopamine and the different kinds of cells in the brain, because there's actually different kinds of dopamine neurons, not only in different areas of the brain, but even in a single area of the brain, there's different kinds.
00:37:50.074 --> 00:38:03.494
And if you're thinking of, like, you know, the logic on a computer chip or something, and you think about every neuron is talking to, you know, a few hundred other neurons, let's say, the identity of that single neuron matters tremendously.
00:38:03.494 --> 00:38:05.235
They're not all doing the same thing.
00:38:05.235 --> 00:38:06.905
They can make different computations.
00:38:06.905 --> 00:38:19.434
So I just think, like, ultimately, and this is kind of my bias showing as someone who likes to think about single neurons and not, blobs of brain activity, but ultimately, like, the answer comes from single neurons
00:38:19.849 --> 00:38:21.809
Wait, I think I need you to, like, explain this a
00:38:22.592 --> 00:38:23.253
Oh, no.
00:38:23.579 --> 00:38:24.449
f- I'm sorry.
00:38:24.449 --> 00:38:30.248
For someone who's not a neuroscientist, like, what do you mean, like, the identity of the single neuron?
00:38:30.248 --> 00:38:34.619
Or can you, can you, like, teach me a little bit more what you
00:38:34.762 --> 00:38:35.253
Sure.
00:38:35.253 --> 00:38:40.793
I mean, there are different ways we define cell types in the brain.
00:38:40.793 --> 00:38:48.063
We could do a whole episode on this if you want, but, we can define cell types by the other brain regions they talk to.
00:38:48.063 --> 00:38:59.233
And so, for example, there might be a cell in the middle of the brain that talks to the cortex and delivers dopamine to the cortex, and that's one sort of signal.
00:38:59.233 --> 00:39:07.773
There could be a cell in that same brain area that talks to another part of the brain, maybe a, quote-unquote, other reward part of the brain, like the nucleus accumbens.
00:39:07.773 --> 00:39:10.952
That's a different signal than the one going to the cortex.
00:39:10.952 --> 00:39:14.773
So yeah, we define neurons based on who they talk to.
00:39:14.773 --> 00:39:17.663
We also define them based on who they get input from.
00:39:17.663 --> 00:39:21.472
Every neuron is an input-output system, and so it's getting different forms of input.
00:39:21.472 --> 00:39:28.742
Um, and then finally, there's other really interesting things, like there's some dopamine neurons that are kinda constantly firing.
00:39:28.742 --> 00:39:30.682
Like, they're just like, doo, doo, doo, doo, doo.
00:39:30.682 --> 00:39:32.302
We call those tonic firing.
00:39:32.302 --> 00:39:34.813
And then there's neurons that do the bursty thing.
00:39:34.813 --> 00:39:36.382
Yeah, exactly.
00:39:36.382 --> 00:39:37.182
Exactly.
00:39:37.740 --> 00:39:42.320
so this is complicating it 'cause you're like, there's really different forms of activity.
00:39:42.320 --> 00:39:47.731
There's different dopamine processes, even if it's the same category of neurotransmitter.
00:39:47.731 --> 00:39:51.641
What's actually happening with it and on what timeframe is actually very different.
00:39:52.179 --> 00:39:56.798
yeah, neurotransmitters are probably not the way to actually divvy up brain activity
00:39:57.043 --> 00:39:58.932
Yeah, it's just an old-fashioned way
00:39:59.411 --> 00:39:59.811
Yeah.
00:39:59.811 --> 00:40:10.760
They're just like, i- in our world, electricity flows via electrons, and it's like, okay, maybe in a different world there could be 10 different kinds of electrons.
00:40:10.760 --> 00:40:15.021
You'd have like, you know, electron, dopa electron, serotonin electron.
00:40:15.021 --> 00:40:23.920
At the end of the day, they're just the signals that are getting passed, and it's not the signal itself that matters, it's where it's being sent and how and, like, to whom.
00:40:23.920 --> 00:40:33.271
So different neurons use the same neurotransmitter for different kinds of signals, and I think this is actually kinda coming back to big picture, like what is dopamine doing?
00:40:33.271 --> 00:40:35.130
It's actually just context dependent.
00:40:35.130 --> 00:40:40.860
It depends on what neuron is releasing it, and on what timing, and where in the brain.
00:40:41.581 --> 00:40:41.780
It's
00:40:41.780 --> 00:40:43.900
not like we can say dopamine does one thing.
00:40:44.523 --> 00:40:46.382
Seems like we need systems neuroscience
00:40:47.306 --> 00:40:53.146
Yeah, we need you know, better experiments teasing apart this stuff, which people are doing, right?
00:40:53.146 --> 00:40:58.547
But it's, it's tough and it's a slow-moving process but in the meantime, don't blame dopamine for everything
