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Ever wish you could just swap your brain out with a spare one?
你有没有想过用一个备用的大脑来和你的大脑交换一下？
If so, sorry.
如果你这么想过，对不起。
We definitely can't grow backup brains in jars.
我们绝对不能在罐子里培养备用的大脑。
But you may have heard about a study in which researchers at the University of California, San Diego
但你可能听说过一项研究，加州大学圣地亚哥分校的研究人员
were able to grow lumps of neural tissue that showed measurable activity -- a little bit like an actual brain.
能生长出显示出可测量活动的神经组织块，它就有点像实际的大脑。
This kind of research raises some ethical questions.
这种研究提出了一些伦理问题。
But the good news is that at this point, it's unlikely the activity in these so-called cortical organoids means they're awake and having experiences.
但好消息是，在这一点上，这些所谓的皮质器官中的活动不太可能意味着它们是觉醒的，并具有经验。
And in this case, they weren't meant to be -- instead they're just a new and uncommon way to study neural tissue,
在这种情况下，它们并不应该是这样的。相反，它们只是研究神经组织的一种新的、不寻常的方法，
which could help model the progression of diseases, test medication, or just understand how humans came to be the way we are.
可以帮助我们模拟疾病的发展、测试药物或者仅仅了解人类是如何变成现在这样的。
In a study reported in the journal Cell Stem Cell in 2019, researchers grew small clusters of neural tissue, like neurons and glial cells, in culture.
2019年发表在《细胞干细胞》期刊上的一项研究中，研究人员在培养物中培养出小簇神经组织，如神经元和胶质细胞。
And the neurons connected and started firing, apparently syncing up with their neighbors.
神经元相互连接并开始放电，显然是与它们的邻居同步。
This was exciting, because before this type of research, we'd had to base our knowledge of how human brains develop on the brains of rodents.
这很令人兴奋，因为在这类研究之前，我们必须将人类大脑如何发育的知识建立在啮齿动物的大脑上。
And based on those kinds of studies, we had thought that human neural tissue needed feedback from other parts of the developing nervous system
在这些研究的基础上，我们认为人类的神经组织需要来自发育中的神经系统的其他部分，
-- as well as the uterus -- to develop and start sending signals.
以及子宫的反馈来发展并开始发送信号。
What's more, the organoids were firing in some patterns that looked like patterns we see in actual brains -- a pattern called a delta wave.
更重要的是，这些有机体以一些类似于我们在实际大脑中看到的模式发射一种三角波。
Basically, they had brainwaves. ...Of a sort.
基本上，它们在某种程度上具有脑电波......
They even found those waves bore some resemblance to existing data on the brains of infants who were born prematurely.
他们甚至发现，这些波与现有早产儿的大脑数据有些相似。
So does that mean these tiny cell clusters were... conscious?
这是否意味着这些微小的细胞团......有意识吗？
Or, at least as conscious as a very young infant?
或者，至少和婴儿一样有意识？
The short answer is probably not.
简短的回答可能不是。
And to explain why it helps to know what a "brain wave" even is.
解释为什么知道“脑波”是什么会有帮助。
Like the rest of your organs, your brain is a cluster of cells -- in this case, neurons and glial cells.
和你的其他器官一样，大脑是一组细胞。在这个例子中，是神经元和神经胶质细胞。
And those neurons generate an electrical signal.
这些神经元产生电信号。
A tiny one -- like, your whole brain is probably not enough to power an old-school light bulb.
非常微小，比如说，你的整个大脑可能不足以为一个老式灯泡供电。
When a neuron fires, an imbalance of sodium and potassium ions gets pushed down the axon toward another neuron
当一个神经元发射信号时，钠和钾离子的不平衡被推向另一个神经元的轴突
-- thanks to channels and pumps in the cell membrane -- which makes an electrical signal.
——这要归功于细胞膜上的通道和泵，它们可以产生电信号。
But individual neurons usually fire kind of randomly.
但单个神经元通常是随机发射信号的。
Their activity as a group is how we get brainwaves.
它们作为一个群体的活动，就是我们如何获得脑电波。
The patterns that look like waves are visualized using a technology called electroencephalography, or EEG,
这些看起来像波的图案是用一种叫做脑电图的技术来显示的，
which detects these changes on your scalp through electrodes.
这种技术通过电极检测头皮上的这些变化。
Each electrode could be about a centimeter wide, so it picks up the activity of a lot of neurons, not one at a time -- which is how patterns like waves tend to emerge.
每个电极都可能有一厘米宽，所以它能捕捉到很多神经元活动，而不是一次一个，这就是波这样的模式出现的方式。
And those waves can be related to what you're doing.
这些波可能与你正在做的事情有关。
Like, high frequency waves, called beta waves, appear when you're thinking hard about something.
比如，当你仔细思考某件事情时，就会出现高频波，叫做β波。
Alpha waves appear when a person is a bit more relaxed.
当一个人稍微放松一点时，就会出现α波。
Then come theta waves, which you might see if you're falling asleep.
然后是θ波，如果你睡着了，可能就会看到它。
Then finally there's delta waves, which are the slowest type of waves.
最后是Δ波，这是最慢的波。
People tend to show these if they're in a deep but dreamless sleep -- or if they're a newborn infant.
如果人们在沉睡，但是没有做梦，或是刚出生的婴儿，他们往往会表现出这些波。
That's the kind of wave these organoids showed.
这就是这些皮质器官显示的波。
So if you were hoping to grow your own backup brain anytime soon, the activity isn't the kind we typically associate with being awake and aware of your surroundings, or even dream perception
所以，如果你希望自己的备用大脑能在短时间内发育起来，那么这种活动就不是我们通常认为的那种清醒、意识到周围环境、甚至是梦境感知的活动了
-- in case any of that was part of your backup brain plan.
——如果这是备用大脑计划的一部分的话。
Some people have argued that we can't really objectively decide if another entity is truly sentient or not -- and so we should be careful with organoids like these.
有些人认为，我们不能真正客观地判断另一个实体是否真的有知觉，所以我们应该小心处理这样的皮质器官。
In fact, some experts are drawing attention to the need for more rigorous ethical boundaries in this research
事实上，一些专家正在提请注意，在这项研究中需要更严格的道德界限，
-- because they believe we are approaching a point where those boundaries are needed.
因为他们认为我们正接近需要这些界限的状态。
Or maybe that we're already there.
或者我们已经到达了这种状态。
For example, in this study, the entire sample of all the organoid clusters they grew amounted to 15,600 neurons.
例如，在这项研究中，他们生长的所有皮质器官簇的整个样本共有15600个神经元。
That sounds like a lot, but it's roughly what you'd find in the nervous system of a sea slug.
听起来很多，但基本上是能在海蛞蝓的神经系统中发现的。
And that wasn't one cluster -- it was the total number in all of them.
这不是一个集群，而是所有集群的总数。
They compared that data to that of newborn infants, all of whom were born before 28 weeks in the womb.
他们将这些数据与未满28周就出生的新生儿进行了比较。
By about halfway through fetal development, they would likely have already developed most of the billions of neurons that babies are born with.
在胎儿发育到一半的时候，他们可能已经发育出婴儿出生时具有的数十亿个神经元中的大部分。
However, even with "only" thousands of neurons, some ethics experts are calling for safeguards.
然而，即使“只有”数千个神经元，一些伦理专家仍呼吁采取保护措施。
After all, a sea slug is a real animal, so this is a fairly complex issue.
毕竟，海蛞蝓是真正的动物，所以这是一个相当复杂的问题。
In humans, we also know of some specific structures that are involved in waking a brain up, as well as arousing it into consciousness.
在人类中，我们也知道一些特定的结构，这些结构与唤醒大脑以及将其唤醒到意识中有关。
One key structure is called the reticular formation.
一个关键性结构叫做网状结构。
This group of neurons sends signals into the rest of your brain to basically wake it up.
这组神经元向大脑的其他部分发送信号，基本上是唤醒它。
Like, if you stimulate this area in anaesthetized rats, they show less of those dreamless-sleep brainwaves, and more of the awake-and-focused waves.
比如，如果你刺激麻醉老鼠身上的这个区域，它们就会显示出更少的无梦睡眠脑电波，更多的清醒和集中的脑电波。
And injury there can result in altered levels of consciousness.
那里的伤害会导致意识水平的改变。
So, at least based on what we know about how bigger brains work, these organoids might need more complex structures to be able to arouse them into being aware and having experiences.
因此，至少根据我们所知道的大脑的工作方式，这些皮质器官可能需要更复杂的结构来唤起它们的意识和体验。
But making working backup brains was never the point.
但让备用大脑发挥作用从来就不是重点。
These organoids are pretty remarkable for other reasons.
由于其他原因，这些有机物是相当了不起的。
For example, the fact that they can sort of model the activity of human brains means we could use them in research
例如，他们能够模拟人脑的活动这一事实意味着我们可以在研究中使用它们，
-- like the way we start with rats and mice before moving to human subjects.
就像我们在转移到使用人类做实验对象之前，是从老鼠开始的一样。
Like, we could see how drugs that could have neurological effects might affect the pattern of activity in a tiny model brain.
比如，我们可以看到可能产生神经效应的药物如何影响一个微型模型大脑的活动模式。
Or, they could be an additional model to use when studying the brains of certain populations, like those with Alzheimer's or schizophrenia.
或者，在研究某些人群的大脑时，比如阿尔茨海默氏症或精神分裂症患者，可以把它们作为一个额外的模型。
If we can develop neural tissue that models these conditions, these organoids could be a stand-in for people's actual brains.
如果我们能开发出能模拟这些情况的神经组织，这些皮质器官可以作为人类实际大脑的替代品。
So it's possible these organoids could lead to more discoveries in the future.
所以这些皮质器官可能在未来带来更多的发现。
And best not to assume you'll be issued a backup brain any time soon.
最好不要以为你很快就会得到后备大脑。
Thanks for watching this episode of SciShow Psych, and thanks to all of our patrons for supporting our content.
感谢收看本期《心理科学秀》节目，并感谢所有支持我们节目的用户。
None of this would be possible without you guys.
没有你们，这一切都不可能存在。
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