2009年9月17日,星期四

What 镜像神经元 are REALLY 做ing

镜像神经元是猴子额叶区域F5中的细胞,在执行动作和感知动作期间均会做出反应。解释为什么这些单元格在动作执行过程中做出响应很容易且没有争议:它们是运动区域中的运动细胞-它们在动作执行过程中做出响应,因为它们参与了动作编码。知觉反应更难解释。首先考虑“规范神经元”,F5中镜像神经元的邻居。像镜像神经元一样,这些细胞在执行动作(例如,抓握)期间做出反应,并且还具有感觉属性(例如,对可抓握物体的呈现做出响应)。规范神经元的感觉反应具有相当直观和标准的解释:对象的抓握需要通过对象的形状来告知(您抓握回形针的方式与柚子不同),因此使用感官输入来驱动适当的抓握手势。重要的是,不假定规范神经元负责视觉识别,它们只是从涉及视觉特征处理的区域接收相关输入。

But what about 镜像神经元? Why would the percept of someone else performing an action such as grasping a piece of food help guide the monkey's own food-grasping action? One thought is that 镜像神经元 support imitation, but apparently macaque monkeys 做n't imitate so that can't be right. So the theory that was proposed early on and completely 做minates (suffocates even) thought on 镜子 neuron function is that these cells support 行动理解. According to this view, the sensory response of 镜像神经元 is not relevant to the monkey's own 行动, unlike canonical neurons. It is rather a mechanism for understanding what other animals are 做ing via motor simulation. The logic is, if I understand what 我是 当我伸手去拿花生时,如果我能在运动系统中模拟另一个人的伸花生动作,我就能理解 他/他 在做。

I have argued that the 行动理解 theory of 镜像神经元 has never actually been tested in monkeys and where it has been tested in the "human 镜子 system" it has been proven wrong: damage to the "镜子 system" 做es not necessarily cause a deficit in 行动理解 (Hickok, 2009). I have yet to see a strong empirical refutation of the evidence I discussed, but a common response that I hear is, "you propose no alternative theory of 镜像神经元."

Although I've never been fond of it's-the-only-game-in-town arguments (a theory can be demonstrably wrong even if we 做n't yet have a better theory) I think the point is worth taking seriously even if it is only partially true. I did propose that 镜像神经元 reflected a form of motor priming, but didn't develop the idea in any detail.

In response to the only-game-in-town argument, here is what I'd like neuroscientists to 做, just for fun. Rather than obsessing on the idea that the sensory response of 镜像神经元 has no relevance to action execution, I'd like folks to 在 least consider the possibility that 镜像神经元, like their canonical neighbors, take sensory input for a motor purpose.

我开始这是推测性的,没有根据,但动作理解理论也是如此,您必须从某个地方入手。认为这是讨论的起点...

我们可以从狗的行为中学到一些东西吗?如果您和狗玩过取情游戏,您可能已经注意到它会迅速学会预测投掷动作的后果。例如,要欺骗一个天真的狗是很不容易的事,因为它会假装扔很多东西。即使球未在空中飞舞,狗仍可能追赶起飞。据推测,动物已经学会了识别投掷动作。这很有趣,因为狗不会抛出,因此也不会抛出镜像神经元。这也很有趣,因为动作观察以某种方式引发了狗的动作执行,追逐。这告诉我们,动物中存在动作观察执行感觉运动电路。狗的运动皮质中甚至可能存在“追逐”细胞,它们在观察动作和执行动作时都会触发。这是一种相同的电路,通过这种电路,声音(参见投掷动作)与气嘴对眼睛(参见飞球)的配对最终会导致眨眼响应(参见追逐)。到音调的存在(参见投掷动作)。

但是狗很聪明。尝试在没有球的情况下进行假投掷,例如,当球仍在狗的嘴里时。您不会得到太多响应(如果您的狗仍然响应,请用更大的球重试该练习,以便狗可以轻松地看到您手中是否有东西)。这很有趣,因为它有点像哑剧,而镜像神经元对哑剧没有反应。您可以想象我们的非镜像动作观察执行电路如何开始表现得像镜像神经元。

The point here is that it is not hard to imagine sensory-motor circuits that take observed 行动 as input and use these 行动 as triggers for any number of executed 行动 via regular old sensory-motor association. The cells underlying these circuits would probably behave like canonical neurons responding both to the execution and observation of the (non-mirror) 行动.

没关系,但是观察动物伸手去拿一块食物怎么会引起观察者的类似动作?换句话说,为什么某些动作会触发镜像动作?在这里,我需要任何了解灵长类动物行为的读者的帮助(我当然不需要)。但是再次根据狗的行为进行推理,我注意到,如果您将球或玩具放在训练有素的狗前面,它可能会监视您并等待(未经训练的狗可能会抓住它)。如果您开始伸手去拿东西,那只狗可能会突然向它猛冲,试图将您击败。狗不是在模仿你(实际上不是),它学会了认识到你的伸手可导致持球,这会触发具有竞争性目标的行动。我可以想象到这种情况是自然发生的,例如食物,其中一种动物朝一块肉的运动触发了狗的竞争性反作用。触发动作可能是人类的触及范围,另一只狗的向前移动,甚至是隐约可见的鸟类飞行或工具的机械动作。重要的是,不是通过运动模拟在狗的运动系统中进行这些动作的识别(至少不是针对人,鸟和工具的动作)。

Presumably monkeys can also learn to recognize 行动 and respond with appropriate 行动 themselves. Observing an aggressive posture might trigger a flee or hit action. Observing a grasp toward a piece of fruit might trigger a competitive "镜子 grasp" for the same piece of fruit. 可能be watching an experimenter reaching for a raisin that the monkey really wants triggers exactly this kind of competitive motor response and maybe this is what 镜像神经元 really reflect. Or maybe it is just another wrong theory about 镜子 neuron function.


Hickok,G.(2009年)。猴子和人类的镜像神经元动作理解理论的八个问题 认知神经科学杂志,21 (7),1229-1243 DOI: 10.1162 / jocn.2009.21189

8条评论:

凯文·希尔 said...

I'恐怕听起来很像是您想替代的理论。如果是狗"认识到您的伸手可及的距离", isn't that just saying he understands the action? It seems that the 镜像神经元 are still intimately involved in the process of understanding an action in a way that pure motor neurons aren't.

At best your just moved 镜像神经元 from the the cause of understanding an action, to the result of an understood action, still in the absence of direct motor function.

This should be pretty easy to test however. There should be a whole host of 行动 where the selfish thing would be to perform a complementary action rather than the same action. (grooming vs presenting your back) So, 镜像神经元 should show a host of asymmetries for certain behaviors.

格雷格希科克说过...

凯文,你好

不不不可以'T be any 镜子 neuron involvement in a 做g'对投掷动作的理解是因为狗's can't 扔 and so 做n't have any motor "throw" cells. The 做g'我的理解是来自其他地方。

I've从未否认狗,猴子或人类可以理解。我只是声称它通过仿真在电机系统中发生。

It sounds a bit like you are confusing 镜像神经元 (cells that show a correspondence between the 行动 they respond to in observation and execution) and plain old sensory-motor cells such as canonical neurons (cells that 做n'不要显示这样的对应关系,即唐't "mirror").

未知说过...

嗨,大家好,

关于狗及其扔飞盘的能力(当然不能),争论似乎有些愚蠢。我认为这一论点没有讲到重点。镜像神经元可能没有反应'actions'本身。根据我的've seen, I would argue that they are mainly responding to the goals of 行动. If you assume that 镜像神经元 are 'mirroring goals' (they respond to the same action simply because the 行动 reflect the same goal, 吃ing in the case of grasping for example) it 做esn'狗可以'扔球,重要的是它们可以代表掷球的目标。关于这一点,激活'eat'通过观察目标肯定会触发执行'eat'动作,假设观察到和执行的动作在目标领域中重叠,这对我来说是完全合理的。

那么问题是,如何检验关于镜像神经元和竞争的想法。我认识一个在荷兰的人Rick van Baaren,他有一个叫做'silverback'他用于社交模仿实验。该装置像骨骼一样附着在受试者的背部,用于测量对社交刺激的姿势反应。我相信,如果人们朝着这个主题前进,那自然就有倒退的趋势,但是中间没有任何对象可以争夺!当然可以改变动态。

所以让's建议进行一项实验,以回答有关竞赛和镜像神经元系统的问题,最好使用健康的成年人和功能磁共振成像。我们如何比较人类MNS's response to competitive goal directed 行动 (a grasp towards a single food item) and non-competitive goal directed 行动 (maybe a grasp to one of many available foods). If the system is there to process competitive goals we might expect the response to be higher for this sort of action. Of course controlling motivation (which we know modulates MNS activity from the study on fasting) and 在 tention (which modulates practically everything) would be a major concern here. But perhaps we can discuss this idea further.

罗杰

格雷格希科克说过...

你好罗杰,

您提出了一些有趣的问题,但让'我将重点放在您关于MN响应目标的观点上,因为我对此有疑问。

首先,猴子伸手来吃葡萄干的行为的目的是什么?目标是达到吗?把握?具有?咬嘴?嚼?吞?增加血糖?是否获得果汁奖励以正确执行任务?为我定义目标的含义,然后我们可以实际了解面向目标的编码是否有意义。

根据你的've说过,您似乎在这种情况下将目标与EAT保持一致:"activation of the 'eat'通过观察目标肯定会触发执行'eat' action..." This would predict that a given MN should respond both to the observation of the experimenter reaching for raisin (which the monkey understands as a preamble to 吃ing?) and to any "eating"猴子方面的行动, which would include reaching for a raisin, peeling a banana, sucking on the juice straw, digging up ants, bobbing for apples, being fed by the investigator. Are you suggesting that MNs would respond equally well to all these 行动? I 做n'认为这将凭经验成立。

Suppose it did though. 可能be any instance of 吃ing on the observation or execution side activated said MN. Then are we still in the motor system? Or are we studying a high-level cognitive behavior? If a cell can in principle code both grasping and ordering from a menu (both preambles to 吃ing) then we are not talking about motor representations anymore. And if we are not talking motor representations then the basis for the 行动理解 claim -- that of motor simulation -- has evaporated, proving that the theory is wrong.

未知说过...

"首先,猴子伸手来吃葡萄干的行为的目的是什么?"

好吧,我的猜测是,至少可以说有立即实现的目标(掌握)和最终实现的目标(有意义)。当我们朝着最终目标前进的过程中,您提出了可能存在许多单独的子目标的可能性。如果我们说某些子目标(咀嚼,吞咽)通常紧紧地排列着/排列起来,以便在某些情况下可以然后考虑作为单个实体,那么我们可能可以重新思考一下。例如,范·希(van Schie)的研究表明,至少对于近期和最终目标而言,大脑机制是分开的(例如额叶与顶叶,不同区域的MN可能具有与目标相关的特性)。"What is a goal"不过,这是一个不错的问题。通常,这给我带来了考虑多种定义的麻烦。


"Based on what you've说过,您似乎在这种情况下将目标与EAT保持一致:"activation of the 'eat'通过观察目标肯定会触发执行'eat' action..." This would predict that a given MN should respond both to the observation of the experimenter reaching for raisin (which the monkey understands as a preamble to 吃ing?) and to any "eating"猴子方面的行动"

猴子中的某些神经元当然会对"logically related" 行动. While we 做n't think of these as "mirror neurons" because they code differnet executed and observed 行动 (i.e. experimenter grasping food and the monkey 吃ing the food i believe is the finding), they 做 seem to code for a common goal to which both are related (i.e. 吃ing). In monkeys they account for <如果我没记错的话,有10%的神经元,但它们在人类中可能会更丰富,我怀疑它们无论如何都是如此。

"Suppose it did though. 可能be any instance of 吃ing on the observation or execution side activated said MN. Then are we still in the motor system? Or are we studying a high-level cognitive behavior? If a cell can in principle code both grasping and ordering from a menu (both preambles to 吃ing) then we are not talking about motor representations anymore. And if we are not talking motor representations then the basis for the 行动理解 claim -- that of motor simulation -- has evaporated, proving that the theory is wrong. "

你知道,我不'现在还不知道答案。我会四肢不停地说,我们大部分时间都在谈论运动表现(我相信有很强的证据表明,我们所谓的认知很多是"embodied")。从菜单上订购涉及某种程度上标准化的运动协议(好的,语言具有无限的可能性,但是在餐厅,我押注单词选择和组合规则受到一定限制)。即使这样,我也同意,单个神经元不太可能因抓握(单个动作)和命令(更复杂的运动现象)而触发。如果一个单元为这两个单元都编写了代码,我想它将符合'higher-order neuron'虽然。没有人说这将在人的镜子区域。在我们可能想到的还有更多抽象目标与任何运动动作都不相关/不相关之后,毕竟对于各种动作理解可能并不需要所有运动模拟,因此可以在其他大脑区域表示出来,我的猜测是肯定的。该走了,星期五。

格雷格希科克说过...

好吧,让'简化并考虑用手,脚,嘴抓。都一样,让's call it, "basic level" goal: to get the raisin and 吃 it.

在观察用脚或嘴抓握时,典型的用手抓握镜神经元是否也会触发?

If so, it is not coding motor 行动 because the motor programs required to grasp with the three different effectors are different. Conclusion: 镜像神经元 做n'通过电机仿真工作;这个理论是错误的。

如果不是(如果该单元仅在观察握力时触发),则即使是最基本级别的目标也不会编码,而抽象的面向目标的编码的想法是错误的。

周末愉快!

埃迪·贝尔 said...

我只是略读了这篇文章,但其中很多内容似乎是基于这样的假设,即狗因为缺乏能力而无法投掷"throwing cells."我认为这也有点...因为缺少一个更好的词,自负(对人类来说比狗要多说)。它'肯定形式的逻辑谬误
结果。

我很清楚,拥有很多狗后,狗非常了解“狗”的概念"通过移动自己的身体来移动某些东西。 "当他要我抚摸他时,我曾用一只边境牧羊犬用鼻子将手移过他的头。我将自己搭配的北京人和马耳他人玩耍,在其中"throws"用嘴巴,用鼻子推动,或"pushes"一起挤压前爪。我不'真的对神经科学了解得很多(比普通的乔要多,但比从事其专业的任何人都少),但说实话,狗可以'容易丢东西的原因是狗缺乏身体或肢体而不是大脑的能力来丢东西。

我只想解决这一点。我没有'看不到这篇文章,我'我不是神经科学人士(嗯,有点。生物学专业/心理学专业,从"生物学就是一切,关于我们的思想,记忆和感受的一切都可以通过神经科学来解释),但是我绝对认为"狗缺乏投掷的大脑能力"推定不仅令人怀疑,而且很可能是错误的。一世'确保您非常了解我们之间的紧密联系,但是似乎您认为我们'比我们离得更远。

珍妮特·阿米吉说过...

我认为我们低估了其他动物的模仿次数。有时由于社会便利而被忽略-但现在的研究表明狗可以学会复制其他狗的运动,甚至复制新的人类运动。更令人着迷的是它们可以将人类的运动转化为自身的身体能力。因此,如果有人用手举起垃圾箱的顶部,那只狗被告知要复制,将用它的嘴做同样的动作。我认为这表明对该行动有相当的了解。