多巴胺:支配人类欲望的双面分子,如何调控它

题图:Cheva用AI生成

再来聊一聊多巴胺的话题，在讨论人工智能还有人脑的工作原理的时候，提到过人的大脑是在进化中形成的，所以它是一个逐步改进的过程，古老的印记并没有从我们基因中消失，而大脑就是这样一个典型，我们大脑可以分为新脑和旧脑，旧脑是在人类进化早期就形成的，它和其他动物的大脑有相同的起源和相似的功能，它主要负责我们的本能反应，也就是不需要思考就能进行的这一部分。而新脑则是指的新皮质，它负责人类的高级神经活动，也是我们人类所有引以为傲的特征的来源，比如意识和理性。它们之间的关系有点类似于我们日常使用的软件和操作系统之间的关系，像Photoshop、Blender这样的软件功能更复杂、更专业。但是它们仍然需要通过操作系统来指挥硬件完成它们下达的任务。

新皮质能够进行复杂的思维活动，甚至认识我们自身和我们所存在的这个宇宙，但是它却不能直接控制我们的身体，它仍然需要通过与旧脑取得一致意见来让旧脑贯彻自己的意志，控制人类的身体。这是因为新皮质没有底层的控制权，如果它与旧脑之间的意见无法达成统一，在这种情况下，往往是由旧脑产生的底层欲望会战胜理智，这大概就是人类为什么会有成瘾行为的原因。比如我们明知道吃零食和甜食对身体不好，但当这些东西出现在眼前的时候，仍然忍不住会伸出手拿来放进嘴里。而那些吸毒的瘾君子就更难控制自己了，如果毒瘾无法满足，就会浑身抓狂，仿佛有无数只蚂蚁在啃食他们的骨头。某种程度上，这就是由旧脑主导的底层欲望战胜了新脑的理性思维。

但如果从更基础、更底层的角度来说的话，这一切都是源于一种叫做多巴胺的分子作祟，多巴胺曾经被认为是快乐分子，是让大脑兴奋和快乐的原因，但实际上它更应该被称为欲望分子，它是让你产生行动的根源。而快乐则是对你行动结果产生的奖励。多巴胺的作用实际上是让你对行动结果的奖励产生欲望，从而采取行动去获得奖励。所以有一种大脑疾病就是因为患者的大脑中缺乏多巴胺分子，它的表现就是这个人对什么事情都提不起兴趣，什么事情也不想做，没有任何的行动能力，如同一具行尸走肉。这么说，现在流行的躺平实际上是一种多巴胺缺乏症了吗？那倒未必，躺平流行的主要原因还是社会的阶层固化和内卷加深，使得获得奖励所付出的行动代价远远超过了奖励本身的价值，才使得躺平青年们不再去努力奋斗了。他们大脑中并不缺乏多巴胺，他们只是不再从现实社会的努力和工作中获取奖励，而是转向虚拟世界，从网络游戏这种更容易获得奖励的地方去释放多巴胺了。

所以，多巴胺也不是一个坏东西，我们所有人类的文明成就，很大程度上都是由这个小分子推动产生的，如果没有它，就没有人会采取行动去追求创新和钻研真理，人类社会就无法进步了。但很不幸，由于旧脑的功能原始，它无法做出准确的价值判断，很多不好的东西也会成为多巴胺分子追求的目标，这就是成瘾性了。如果你做了一件坏事，结果却反而获得了奖励，那么在多巴胺分子的驱动下，下次碰到了同样的机会，你有极大的可能会再次去做这件坏事，因为根据以往的经验，它会带来奖励。

那人类真的就没有办法对抗这种在底层架构上操纵我们的小分子了吗？理论上，如果有强大的意志力，让新脑的决策压过旧脑，就可以控制成瘾性的行为，但是人脑的这套新脑和旧脑的系统毕竟是在长期演化中形成的，要付出多大的毅力，才能够控制成瘾，让成瘾行为有所改变，其困难程度是可想而知的。但也不是不可能。根据研究，要打断一个坏的行为的成瘾，坏的成瘾行为的多巴胺通路，大约需要保持不触发它一个月左右的时间，。就是说，要克制住自己的不良嗜好长达一个月，看似时间不长，要做到还是难度不小的。因为现代社会很多东西都是触手可及的，欲望也是无所不在。但是神经科学家们却提出了一种看似有些不可思议的解决方案——以痛治痛。

就是反其道而行之，通过痛苦的体验来抑制这种对不良奖励的渴望。这一方法的原理很简单，就是大脑天生有自我平衡的能力，就是当你在收获奖励感到快乐的时候，大脑也会分泌一些痛苦的分子，这就是为什么很多人当欲望得到满足之后，反而会感到精神更加空虚了。同理的，如果当你感受到了痛苦，大脑也会分泌一些快乐分子来让你好受一点，这其中就包括大名鼎鼎的内啡肽分子。当然让自己获得痛苦体验并不是为了要去自残或者伤害自己，又或者像某些宗教中的苦行僧那样采取近乎自虐的修行方式。不过这些行为倒是与这个理论吻合得很好。最简单的实践这一理论的方式就是体育锻炼，通过大运动量的锻炼让身体处于一种缺氧的状态，当完成运动目标，身体松弛下来获得充足的氧气的时候，大脑就会释放内啡肽，平衡剧烈运动过程中产生的不适感，从而让你体验到一种快乐和轻松的感觉，取代多巴胺分子驱动的欲望、奖励通路所带来的愉悦、愉悦感，这样可以帮助你更好的摆脱不好的成瘾行为。

---

To talk about the topic of dopamine, when discussing artificial intelligence and the working principle of the human brain, it is mentioned that the human brain is formed in evolution, so it is a gradual improvement process, the ancient mark has not disappeared from our genes, and the brain is such a typical, our brain can be divided into new brain and old brain, the old brain is formed in the early stage of human evolution. It has the same origins and similar functions as the brains of other animals, and it is mainly responsible for our instinctive reactions, the parts that do not need to think. The new brain is the neocortex, which is responsible for higher neural activity in humans and is the source of all the features we humans are proud of, such as consciousness and reason. The relationship between them is somewhat similar to the relationship between software and operating systems that we use every day, with more sophisticated and specialized features like Photoshop and Blender. But they still need the operating system to direct the hardware to accomplish the tasks they give them.

The neocortex can carry out complex thinking activities and even understand ourselves and the universe in which we exist, but it cannot directly control our bodies, it still needs to agree with the old brain to let the old brain implement its will and control the human body. This is because the neocortex does not have the control of the bottom layer, if the opinion between it and the old brain can not reach a unity, in this case, often the bottom desire generated by the old brain will prevail over the reason, which is probably the reason why humans have addictive behaviors. For example, we know that eating snacks and sweets is not good for our health, but when these things appear in front of us, we still can't help but reach out and put them in our mouths. Those who are addicted to drugs are more difficult to control themselves, and if their addiction is not satisfied, they will be mad as if millions of ants are eating their bones. In a way, this is the triumph of the old brain's underlying desires over the new brain's rational thinking.

But if you look at it from a more basic, more basic level, it all comes down to a molecule called dopamine, which used to be thought of as a pleasure molecule, which is what makes the brain excited and happy, but it's actually better called a desire molecule, which is what makes you act. Happiness, on the other hand, is a reward for the results of your actions. What dopamine does is actually make you want a reward for the outcome of your action, so that you take action to get that reward. So there is a brain disease because of the lack of dopamine molecules in the patient's brain, it is manifested that the person has no interest in anything, does not want to do anything, does not have any ability to move, like a walking dead. So, the current fad for lying flat is actually a dopamine deficiency? That is not necessarily true, the main reason for the popularity of lying flat is the solidification of social strata and the deepening of internal volume, so that the action cost of obtaining rewards far exceeds the value of the rewards themselves, so that lying flat young people no longer struggle. They don't lack dopamine in their brains, they just stop getting rewards from real social effort and work and switch to the virtual world, where it's easier to get rewards from online games.

Therefore, dopamine is not a bad thing, all of our human civilization achievements, to a large extent are driven by this small molecule, without it, no one will take action to pursue innovation and study the truth, human society can not progress. But unfortunately, due to the primitive function of the old brain, it can't make accurate value judgments, and many bad things will become the target of dopamine molecules, which is addiction. If you do a bad thing and you get rewarded for it, then the next time you have the same opportunity, driven by dopamine molecules, you are more likely to do the bad thing again, because it brings rewards based on past experience.

So is there really no way for humans to fight the small molecules that manipulate us on the underlying architecture? In theory, if there is a strong willpower, so that the decision of the new brain over the old brain, you can control addictive behavior, but the system of the new brain and the old brain of the human brain is formed in the long-term evolution, how much perseverance to pay, to be able to control addiction, so that addictive behavior has changed, its difficulty is imaginable. But it's not impossible. According to research, to interrupt a bad addictive behavior, the dopamine pathway of bad addictive behavior needs to remain untriggered for about a month or so. That is to say, to restrain their bad habits for up to a month, it seems that the time is not long, it is still difficult to do. Because many things are within reach in modern society, desire is everywhere. But neuroscientists have come up with a seemingly unthinkable solution - treating pain with pain.

Is to do the opposite, to suppress the desire for bad rewards through painful experiences. The principle of this method is very simple, is that the brain is born with the ability of self-balance, that is, when you feel happy in the harvest of rewards, the brain will secrete some pain molecules, which is why many people when the desire is satisfied, but will feel more empty spirit. Similarly, when you feel pain, your brain also releases happy molecules to make you feel better, including the famous endorphin molecule. Of course, the purpose of subjecting oneself to painful experiences is not to self-harm or harm oneself, or to practice in a way that borders on masochism, as the ascetics of some religions do. But these behaviors fit nicely with the theory. The simplest way to put this theory into practice is physical exercise, through a large amount of exercise to let the body in a state of hypoxia, when the completion of the exercise goal, the body relaxes to get enough oxygen, the brain will release endorphins, balance the discomfort generated during the strenuous exercise process, so that you can experience a happy and relaxed feeling. Replacing the dopamine molecule-driven desire, pleasure, and pleasure of the reward pathway can help you better get rid of bad addictive behaviors.