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  • So we've just seen that according to the 2nd

  • Noble Truth, the source of Dukkha, the source of

  • suffering and unsatisfactoriness is our craving, our attempt to

  • hang on to 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 p, 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.

  • [SOUND] Now in Buddhist writing when, 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 doughnuts, you know, There's no point

  • where I'm you know, thinking that there are

  • foreign agents conspiring to assassinate me or anything.

  • There' not even a point where I

  • actually think the pleasure's going to last forever.

  • In fact, If you said, well do you think

  • it's going to last for 10 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 then about the evaporation of the

  • pleasure and I'm certainly not thinking about you know, well maybe the sugar

  • rush will subside and then [UNKNOWN] I'm just focused on that moment of pleasure.

  • Now in other cases something more like delusion may actually happen.

  • You know, with infatuation.

  • If you've ever had a serious crush on someone, you, you may

  • recall that you know, you had a pretty distorted view of things.

  • You, 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 as

  • to find yourself in a relationship with

  • that person, everything would be better probably eternally.

  • And you know, relationships needless to say are

  • in fact you know, more complicated than that.

  • And so, too, with a, with say, a job you really want.

  • You're, you know, 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

  • could just get this job, then you could relax.

  • Then you will have, arrived.

  • But of course, you haven't really arrived, you know, 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've

  • 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 is it just correlated with pleasure.

  • The for our purposes the, the mere correlation is pretty much

  • enough, the 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 with 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 happened.

  • So that is a dopemamine spike.

  • If you want to ask, how long does that last?

  • How, how long are we talking about along that horizontal axis?

  • Well, that's about a third of a second of dopemine spike.

  • So, assuming that in this monkey dopamine is correlated with pleasure.

  • You know that's, that's pretty brief pleasure.

  • You know if monkeys could talk he might have said

  • this particular monkey might have said wow that was impermanent.

  • You know?

  • 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.

  • You know, if, if monkeys and humans are exhibiting some of the same dynamics.

  • [SOUND] 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, you know, you could keep dishing

  • out dopamine for 10 seconds, 20 seconds, in principle.

  • But that doesn't happen.

  • Why is that?

  • And, and, and why do we seem, you know, 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, designed 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?

  • You know, if we wanted them to get their genes to their next generation.

  • Now, granted that eating helps them do that by keeping them alive.

  • Sex obviously helps them do that.

  • And even with humans and non-human primates, things like elevating their

  • social status helps them do that because it seems to be the

  • case that in primates and some 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 3 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, you know.

  • And, and, and never felt the, the unpleasant

  • sensation of hunger again, you would never eat again.

  • You would die.

  • Okay?

  • And if you had sex and then just kind of basked in the after glow for a really

  • long time, thinking about how wonderful it'd been, you

  • know, and meanwhile, in your species some other animal

  • had sex, said that was great, but you know

  • I'm starting to feel restless, I think I'll 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 you know, not being satisfied

  • for very long, that that animals 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, okay?

  • You know obviously if you're focused on that pleasure.

  • If you're focused on, on how good it's going to

  • feel to reach the goal, you'll reach the goal.

  • Whereas if you're sitting there thinking you know, the pleasure's

  • going to be over in a nanosecond, why work so hard?

  • Well you know, you're going to probably wind up, you

  • know, sitting in your room alone full of ennui.

  • Reading existential philosophy or something, you know, and that's definitely

  • no way to get your genes into the next generation.

  • So, I would say that these, these three principles of design they make sense

  • in terms of natural selection and they,

  • 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, and, 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 the fleetingness of the pleasure.

  • And that to makes sense in terms of natural selection.

  • Focusing on the pleasure is a good motivator.

  • Okay, let's 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, you know, 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, you know, 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, you know, focusing on the pleasure that is

  • to come in somewhat the way that we humans seem to.

  • right?

  • I mean, it's, you know, anticipation is not, is not just pleasure.

  • There's also an anticipation, a kind of eagerness, a kind of excitement.

  • But there is also you know, 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, in all the experiments done of the 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, you know, 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 time comes when I decide that, that I deserve it.

  • And you know, I, I'm, I'm thinking about it.

  • It's, I can taste it.

  • It's feeling good, I go downstairs, I get some.

  • I may you know, in a sense, not experience the pleasure at all.

  • It's, the whole routine has become so automatic that

  • I may just, be thinking about some, something else.

  • My mind may be wandering, okay?

  • so, again this is the complete suppression of

  • a dopamine spike, is you know, an extreme case.

  • What we, 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 you know, I'm in a convenience

  • store, I see that pack of powdered sugar donuts.

  • I'm thinking about eating it it's, it's, it's all good, you know.

  • I, I go and I I, I grab it, take it to the counter, I buy it.

  • [SOUND] And then I eat it and yeah, i, it's okay.

  • It's okay.

  • eh, but, you know, each successive bite is less okay.

  • It's fine, but the anticipation was, was maybe where most of the pleasure happened.

  • Okay?

  • Because at this point, I've done the work.

  • The motivational system has, 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 you know 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

  • you know, this, this science is still being worked out.

  • There are different interpretations of this kind of data

  • and you know, the, 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.

  • You know, fruits had sweetness, fruits were good for you and

  • so that seems to be why we have a sweet tooth

  • that kind of, kind of now go overboard you know, in

  • a, in a convenience store now that, 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 pre-human, spots some

  • trees off in the distance and they look like they might be fruit trees.

  • And, you know, it's a hot day, it's a long walk.

  • The animal's not crazy.

  • About doing that work.

  • But it many fruit trees, the animal remembers this taste of fruit.

  • And, you know, gets a little bit of a, gets a little

  • bit of a dopamine spike and that motivates it to go investigate.

  • And it, it, 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 its 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, like, my, 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, you don't just get an absence of dopamine

  • spike, you get a, a deficit of dopamine activity, okay?

  • This, this presumably corresponds to what I would

  • call the let down of, of unfulfilled anticipation.

  • You know, you've probably done this.

  • You know, gone to the refrigerator, you're,

  • 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.

  • Oh there's no fruit.

  • These aren't fruit trees.

  • Well, you want them to not go over to those particular trees again.

  • If you, you know, if you are building their brain you want them

  • to avoid those trees, you want this to be a, an unhappy experience,

  • so that's, that's it's what makes sense; that it would be, 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, okay.

  • There is this correspondence between the way you

  • would expect natural selection to design, design a brain.

  • And some basic principles of Buddhism.

  • Buddha says 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, you know, 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, the face is actually not objectively viewed angry in menacing.

  • And these were cases when natural selection

  • kind of built illusion into the system.

  • And now we, 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 selections 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, 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 Buddhists' specific strategy

  • for Realizing these, these goals of ending suffering.

  • And helping us see the world clearly.

  • So, to see that, you need to look at the, the 3RD and 4th Noble Truths.

  • The Buddhists prescription for the human predicament, and that's

  • what we're going to turn to in the next lecture.

So we've just seen that according to the 2nd

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演化心理學和最初的兩個真理(1 - 4 Evolutionary Psychology and the First Two Noble Truths (sub: eng/rus) / 1-4 Эволюционная ..)

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    benyei Wei 發佈於 2023 年 01 月 22 日
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