So, we've just seen that according to the second noble truth, the source of dukkha, the source of suffering and unsatisfactoriness is our craving, our attempt to hang onto things that don't last, including pleasure. And I used powdered sugar donuts as my own personal example of that. The Buddha, as we saw, said that our failure to kind of grasp this dynamic was just another example of our failing to see the world clearly. Now, in this segment of lecture one, we're going to drill down a little into the biological mechanics of craving and of the evaporation of pleasure, and we're going to ask why it is that if the Buddha was right, why it is that we do fail to get the picture about pleasure and how fleeting it is. Now, in Buddhist writing, when the Buddha talks about our failure to see things clearly, he often uses a word that is typically translated as delusion. But, I want to emphasize that sometimes that word is a little bit of an overstatement, so for example, when I'm gazing at powdered sugar donuts, there's no point where I'm thinking that there are foreign agents conspiring to assassinate me or anything. There's not even a point where I think the pleasure is going to last forever. In fact, well do you think it's going to last for ten minutes, I'd probably say no. But at the same time, as I look forward to eating those donuts, I'm thinking a lot more about the pleasure than about the evaporation of the pleasure. And I'm certainly not thinking about, well, maybe the sugar rush will subside and then I'll feel all unsettled. I'm just focused on that moment of pleasure. Now in other cases, something more like delusion may actually happen with infatuation. If you've ever had a serious crush on someone, you may recall that you had a pretty distorted view of things. You had a lot of trouble seeing any blemishes or deficiencies in the person. It was all good, right? And there was this idea that, wow, should you ever be so lucky to find yourself in a relationship with that person, everything would be better, probably eternally. And relationships, needless to say are, in fact, more complicated. And so too with say, a job you really want. If you really want that thing you're looking forward to it, thinking about all the great things it's going to bring, you're not thinking about the hassles that all jobs bring, and there may be a sense that if you can just get this job, then you can relax. Then you will have arrived. Of course, you haven't really arrived. The gratification is not going to last forever. It never lasts forever. Now, if you want to look at parts of the brain that are relevant to the failure of gratification to last forever. One obvious candidate would be the neurotransmitter dopamine. If you read much in the Popular Science press you probably read about dopamine as the pleasure chemical, the reward chemical. The true story is actually a lot more complicated than that. The effects dopamine has depend on the part of the brain you're in, which neurons are involved, which receptors are involved, and so on. There's also the question of does dopamine actually cause pleasure, or just correlated with pleasure. For our purposes, the mere correlation is pretty much enough a fact that dopamine seems to be correlated with pleasure. So we're going to look at a little data from a study in which they monitored very precisely the neurons in monkeys that are involved in the release of dopamine and are in a part of the brain where dopamine seems to be correlated with pleasure and reward. So what they did, they gave a little fruit juice to a monkey, and here's what happen. So that is a dopamine spike. If you want to ask how long does that last, how long are we talking about along that horizontal axis, well that's about a third of a second of dopamine spike. So assuming that, in this monkey, dopamine is correlated with pleasure, that's pretty brief pleasure. If monkeys could talk he might have said, this particular monkey might have said, wow, that was impermanent. Maybe the monkey condition is very much like the human condition and pleasure just tends to evaporate pretty rapidly. And if that is the case, then that's all the more reason to look at natural selection as a possible explanation for why pleasure does evaporate, if monkeys and humans are exhibiting some of the same dynamics. So the question is, why does natural selection build brains like this, where pleasure is so fleeting? Why not just leave that dopamine spigot on? You could keep dishing out dopamine for ten seconds, 20 seconds, in principle, but that doesn't happen. Why is that? And why do we seem not to really get the picture in our everyday lives about how rapidly the pleasure is going to dissipate. Why did natural selection design our brains like this? Now, as I've said before, whenever I say something is designed by natural selection, design should be in quotes. Natural selection is not a conscious designer. Still, it does create animals that look as if they were designed by a pretty smart designer with one thing in mind, to get them to get their genes into the next generation. So it is a fair thing to do, as a kind of thought experiment, to put ourselves in the shoes of natural selection and ask, if we were designing organisms, how would we design their brains? If we wanted them to get their genes in their next generation, granted that eating helps them do that by keeping them alive, sex obviously helps them do that. And even with humans and nonhuman primates, things like elevating their social status helps them do that, because it seems to be the case that in primates and some other parts of the animal kingdom, social status is correlated with getting genes into the next generation. So it is a fair question. How would you design these brains if you were natural selection? I would submit that there are three principles of design that would make sense if you want animals to reach these goals. Okay, first of all, when animals do reach the goals, they have food, they have sex, they should get some pleasure. Pleasure is what reinforces behavior, makes animals more likely to do whatever led them to the goal in the first place. Principle number two, the pleasure should not last forever. Obviously, if you ate one meal and just blissed out and never felt the unpleasant sensation of hunger again, you would never eat again, and you would die, okay? And if you had sex and then just kind of basked in the afterglow for a really long time, thinking about how wonderful it had been, and meanwhile, in your species, some other animal had sex, said well that was great, but said I'm starting to feel restless, I think I'm going to go get some food or do something to elevate my social status, or maybe go find some more sex. Well, that animal's going to get more genes in the next generation than you will. So, these genes for restlessness And for not being satisfied for very long, that that animal has are going to do better than your genes. The third principle of design, I would submit, is that animals should focus more on the pleasure that reaching goals will bring than on the subsequent evaporation of the pleasure. Obviously, if you're focused on that pleasure, if you're focused on how good it's going to feel to reach the goal, you'll reach the goal. Whereas if you're sitting there thinking, pleasure's going to be over in a nanosecond, why work so hard? Well, you're going to probably wind up sitting in your room alone, full of ennui, reading existential philosophy or something. And that's definitely no way to get your genes into the next generation. So, I would say that these three principles of design, they make sense in terms of natural selection, and they help make sense of Buddhist teaching, right? The Buddha said that pleasure tends to evaporate, and it leaves us unsatisfied. And it seems to be the case that pleasure is designed to evaporate so that it will leave us unsatisfied. And we will be motivated to go out and do more work and check off more bullet points on natural selection's agenda. The Buddha said we seem not to get the picture about pleasure. We focus on the pleasure and not on the fleetingness of the pleasure. And that, too, makes sense in terms of natural selection. Focusing on the pleasure is a good motivator. Okay, let's get back to that monkey. Now, in the data we saw about that monkey's brain, we didn't see anything about anticipating pleasure. And that's because, in that case, the monkey couldn't anticipate the pleasure because the fruit juice came out of the blue. The monkey was not expecting it, they just dropped it on the monkey's tongue. However, later in the experiment, they did make anticipation possible. What they did was when they turned on a light, it meant that if the monkey would reach over and touch a lever, then there would be fruit juice. And they trained the monkey to behave in accordance with that principle. And here is what you see in that case. So here, the light goes on. We're in the zone of anticipation, and now you see a dopamine spike here. And that seems to be, I mean, you can't get inside the monkey's brain, but it's a reasonable conjecture that what's happening is the monkey is anticipating the pleasure, focusing on the pleasure that is to come in somewhat the way that we humans seem to, right? I mean, anticipation is not just pleasure, there's also an anticipation, a kind of eagerness, a kind of excitement, but there is also a kind of imagining of the actual pleasure that you're going to experience when you get the reward. You actually have some of that feeling, and that may be one thing that's being captured here in this dopamine spike. Now, interestingly, when the food actually shows up, what you see is this. They give the monkey the fruit juice, and there's no elevation of dopamine activity now. Now, I should emphasize this is kind of an extreme case. They don't find in all the experiments done of this sort, they don't always find that there's a complete suppression of the dopamine spike upon reward, and the other thing is that it took a lot of training to get the monkey to this point. So the behavior became really automatic. I might kind of liken it to, in my case, again to return to one of my vices, dark chocolate. Every afternoon, I have some dark chocolate. The times comes when I decide that I deserve it. And I'm thinking about it, I can taste it, it's feeling good. I go downstairs, I get some, I may, in a sense, not experience the pleasure at all. The whole routine has become so automatic that I may just be thinking about something else, my mind may be wandering. So again, this is the complete suppression of a dopamine spike, is an extreme case, but what is quite common, what we can say is a pretty common dynamic is that, again, originally what you have is you get the reward. You get the spike in dopamine activity, and then when the animal starts to be able to anticipate the reward, light goes on, get a pretty big dopamine spike, you get the reward, and then you get a much smaller spike than what you got before. And again, if I would conjecturally relate this to my own experience, I might guess that this is like I'm in a convenience store. I see that pack of powdered sugar donuts. I'm thinking about eating it. It's all good, you know. I go, and I grab it, take it to the counter, I buy it. And then I eat it and, yeah, it's okay. It's okay. But each successive bite is less okay. It's fine, but the anticipation was maybe where most of the pleasure happened. Because at this point, I've done the work. The motivational system has gotten me to do the necessary work to obtain the food, to reach the goal. So, you don't need a lot of additional motivation at this point, and we don't see a whole lot of additional reinforcement here. Now, I want to emphasize again that this is pretty speculative, not just because we cannot get inside a monkey's brain. We don't know what's going on there, but because this science is still being worked out. There're differing interpretations of this kind of data. And the story will continue to evolve, but it is consistent with the kinds of motivational dynamics that we would expect from a brain built by natural selection. Now, you may ask, why would natural selection have designed brains that are attracted to powdered sugar donuts, because after all, they're not very good for us. And the answer is, natural selection didn't because after all, powdered sugar donuts were not part of the landscape when our lineage evolved. What was part of the landscape was just sweetness. Fruits had sweetness, fruits were good for you, and so that seems to be why we have a sweet tooth that can kind of now go overboard in a convenience store now that junk food exists. So to give you an example of the kind of dynamic that may have been at play during evolution when there were no powdered sugar donuts, imagine one of our distant ancestors, maybe early human, even prehuman, spots some trees off in a distance, and they look like they might be fruit trees. And it's a hot day, it's a long walk, the animal's not crazy about doing that work, But it may be fruit trees, the animal remembers this taste of fruit. And you know get's a little bit of a dopamine spike and that motivates it to go investigate. It takes a trek, gets there, there is fruit, eats it, you know a little more pleasure. You don't need a lot of pleasure at that point, you may not need a huge spike. But enough for a little reinforcement, and you know the brain built by natural selection has done it's job, okay. Now you may ask, if in cases where we are very used to the pleasure we're getting. You know, it's become routinized, like my eating the chocolate in the afternoon, so that often there's little, if any, pleasure in the actual eating of the chocolate and more pleasure in the anticipation. Why don't we just do the anticipation and then skip the eating? Because that's where the joy is anyway. And the answer, as to why this won't work. Is this, when they turn the light on for this monkey and then don't deliver the fruit juice, you don't just get an absence of dopamine spike, you get a deficit of dopamine activity. Okay? This presumably corresponds to what I would call the let down of unfulfilled anticipation. You've probably done this, gone to the refrigerator, you're looking forward to that piece of cake, you open it, somebody's eaten the cake. You don't just feel an absence of pleasure, you're actually let down. And this too makes sense as a motivational device. You know if you want to return to that scenario of our early ancestors. Say they see the trees in the distance, could be fruit trees, they're motivated, they go over there. There's no fruit, these aren't fruit trees. Well, you're wanting to not go over to those particular trees again. If you are building their brain you want them to avoid those trees. You want this to be an unhappy experience. So it makes sense. That it would make them actively unhappy to expect something, and do some work to get it. And then not find it. So just to summarize, there is this correspondence between the way you would expect natural selection to design a brain, and some basic principles of Buddhism. Buddha said pleasure doesn't last, leaves us unsatisfied, evolution seems to explain why. Buddha says we focus on pleasure and not on the fleetingness of pleasure, evolution seems to explain why. And this is another example of how natural selection doesn't care, care in quotes, of course, care whether we see the world clearly. We've already seen that sometimes, it might be natural for us to see a snake that's not there. For us to see an angry menacing face, when in fact the face is actually not objectively viewed angry and menacing. And these were cases when natural selection kind of built illusion into the system. And now we see another sense, in which natural selection seems not to care if we don't see the world clearly. We also see something else here. Which is that natural selection seems not to care if we're happy. From natural selection's point of view, happiness is just a tool. If making us happy at one moment will keep us motivated, fine. If making us unhappy, if making us unsatisfied, if making us suffer will get us to do the work that's on natural selection's agenda then fine, in those cases that will be the case. I said earlier that Buddhism is in a sense a kind of rebellion against natural selection. And now you can see one sense in which that's true. Because, you know, Buddhism wants us to see the world clearly all the time, and aspires to end our suffering. Natural selection wants us to sometimes not see the world clearly, and wants us to suffer sometimes. So, clearly, you know, the Buddhist program is to some extent in opposition to the logic of and the implicit goals of natural selection. But in a way, I think we haven't even seen the half of it, really. To see the full scale of what I call the rebellion of Buddhism against natural selection. You need to see the Buddhist specific strategy for realizing these goals of ending suffering, and helping us see the world clearly. So, to see that you need to look at the third and fourth noble truths. A Buddhist prescription for the human predicament. And, that's what we're going to turn to in the next lecture.
