迈克尔-波伦(Michael Pollan)近期在《纽约人》（New Yorker或译《纽约客》）杂志上发表了一篇文章《聪明的植物》（The Intelligent Plant）。不知为什么现在该杂志的网站打不开。这是他在《科学星期五》1月3日节目中的谈话节选。
(1)
即使是使用植物神经生物学这个术语的人也并不是说它们有神经，不是说它们有脑子，它们没有类似的结构，而是说它们有处理在其日常生活中收集的所有感知数据的方式，指出这一点是重要的。顺便说一下，它们有比我们还多的感觉，它们有15到20不同的感觉。
哦，除了我们所具有的5种感觉，我们的5种它们都有。我们刚发现它们能听，这是个很新的东西。如果你对一棵没有受到毛虫攻击的树播放毛虫吃树叶的声音，它就将开始武装自己，生产防御性化学物质。……它们还有，它们能感知重力，它们能感知体积，它们能感知水、毒素、盐。体积，我的意思是，你知道，感知在它们地里的物体并做出反应。
所以这问题就变成了你如何处理这么多的感知信息，整合它，然后以适当的行为作出反应。而它们是在没有脑的情况下做到的，以一种难以置信的方式。因为我们很自然地假定处理信息并作出合适的反应是需要脑的。这提示我们，也许存在着完成这一任务的另一种途径。
(03m25s)
And it’s important to point out that even the people who use the term plant neurobiology, are not saying they have neurons; are not saying they have brains; they have not analogous structures, which is to say they have ways of taking all the sensory data that they gather in their everyday lives. And they have, by the way, more senses than we do. They have between five and twenty distinct senses. And then…
Oh, well, in addition to our five - they have all five of our senses. We just discovered that they can hear. That’s a pretty new thing. If you play a recording of a caterpillar chomping on a leaf for another plant that hasn’t been attacked by caterpillar, it will begin to arm itself and produce defense chemicals... So, but they also have, they can sense gravity, they can sense volume, they can sense water, toxin, salt, volume, I mean, you know, objects in their field and react.
So the question becomes how do you take in that much sensory data, integrate it and then behave in an appropriate way in response. And they do this without brains, which in a way is what’s incredible about it because we automatically assume you need a brain to process information and come up with the appropriate behaviors. And they are suggesting, well, there might be another way to do it.
(2)
啊，它们没有神经细胞。它们确实有细胞和电信号传送，它们也有神经递质，尽管它们的功能尚不清楚。它们制造羟色胺和多巴胺和谷氨酸盐[注]等化学品——这些同样也是你的脑用来感知周围信号的化学品。我们不知道它们为什么会有这些化学品，不过看来，你知道，也许这只是进化过程中保留下来的，也许进行某种形式的信息处理功能。我们不知道，有很多东西我们都不知道。我的意思是，它们很怪异，它们与我们非常不同，这需要一整套完全不同的信息处理和网络联系的模型，甚至‘行为’这个词对于许多人来说不适用于植物。因为我们自然地把行为和动作联系起来。不过行为之于植物是非常缓慢和难以察觉的除非你谈的是诸如捕蝇草之类的东西。不过一个行为可能是一种化学品的排放，比如说一个化学的警告或报警，它也可能是一条根的运动。关于植物的真正有趣的事情之一是当它们向外伸展根系和要面对一个它们不能穿过的物体时，它们甚至在到达这物体之前就将改变方向。因此，是什么在指导它们的运动？这些就是植物神经生物学试图弄清楚的一类问题。
[注]：谷氨酸盐是一种氨基酸，但又有神经递质的作用。
(05m05s)
Well, they don’t have nerve cells. They do have cells and electrical signaling, ah, they also have neurotransmitters, although what their function is is not clear. But they produce serotonin and dopamine and glutamate, some of the same chemicals that your brain uses to sense signals around. We don’t know why they have them, but they seem to have, you know, whether it is just a conserve through evolution or perform some sort of information processing function. We don’t know, there is a lot we don’t know. I mean they are very weird and they are very different from us and it requires a whole different model of thinking about information and networking, and even the word behavior, which to a lot of people doesn’t seem to fit plants because we, you know we automatically equate behavior with movement. But behavior to a plant is very slow and hard to detect unless you talking about something like a Venus flytrap. But a behavior might be the emission of a chemical, say a warning chemical or alert, it might be the movement of a root. One of the really interesting things about plants is when they are sending out their roots and about to confront an object that they can’t get through they will change direction even before they get there. So what’s directing their movements? And those are the kinds of questions that the plant neurobiology is trying to get to the bottom of them.
(3)
她采用了含羞草也称感应草做试验。我不知道你见过没有，看起来有点像蕨类植物。你碰它一下它的叶子就垂下来。这也许是对于昆虫的一种防御。它们很酷，很酷。她发现如果它们种在罐中你丢下其中之一它也会下垂其叶子。于是她设置了一个装置，她把一束植物种在罐中，把它们装到一个设备上，在一个训练期内，这个装置每5秒钟就把它们扔下一次，看看能否训练它们忽略这种刺激——知道这种刺激是无关的。这是一种被称为去习惯化的试验。她发现在5或6次被扔下之后这种植物就像是已经学会作为无关信息而排除这种刺激。知道在你的环境中什么可以安全的忽略这当然是学习的一个非常重要的部分。
你也许认为它们只是厌倦了，你知道，我们有时厌烦而不愿意再作出反应。不过她发现对于另一种刺激，比如摇动它们就会继续下垂。看来它们已经区别出这是一种可以安全地忽略的信号。更让人难以置信的是她在接下来的4周中每周重新测试一次，这一个月的时间它们一直记得它们所学到的：不应该对这种扔下刺激作出反应。因为她的测试没有再继续下去，它们也许记得更久呢。她指出，如果你对蜜蜂作这类去习惯试验，它们会在48小时之后忘记学到的内容。而植物能保持对这种刺激的记忆和为什么它能被忽略。
它们是如何做到这个的？我们不知道。也许是所谓的表征遗传效应的一种，围绕着DNA的许多分子出现变化，它们影响哪些基因可以被表达，哪些不被表达。不过我们对此不能确信。
(08m08s)
She took mimosa, which is also called the sensitive plant. I don’t know if you ever seen one. It’s a plant that looks a little like a fern. You touch it and the leaves collapse. It’s probably a defense against insects. They are very cool. They are very cool. So she found out that if you dropped one of them if it’s in a pot it would also collapse its leaves. So she set up, she potted a bunch plants and sets them on a contraption that will drop them every five seconds in a series of training sessions to see if she could train them to ignore that stimulus as irrelevant. This is a kind of learning called dishabituation. And she found that after five or six drops the plants would stop responding as if they had learned to tune out this stimulus as irrelevant. Of course it’s a very important part of learning to know what you can safely ignore in your environment.
And now you might think of maybe they were just talked out, and you know we were tired of doing the response. But she found that another kind of stimulus, such as shaking they would continue to collapse. So that they had made the distinction that this was a signal they could safely ignore. And what was more incredible is that she would retest them every week for four weeks. And for a month they continued to remember their lesson that you shouldn’t react to the drop stimulus. That is far out of she tested they may remember longer. She points out that if you do a dishabituation experiment on bees; they forget what they’ve learned in forty-eight hours. So this is rather impressive that they can hold the memory of this stimulus and why it can be ignored.
How they do that? We don’t know. It maybe one of the so called epigenetic effects where there is a change to the casing of the molecules around the DNA that affects which genes get expressed and which ones don’t. But we don’t really know for sure.
(4)
植物能做惊人的事情。它们看来确实能记住压力和例如上面试验中的事件。它们确实有能力对15到20种环境事件作出反应，对于这些变化进行处理并做出相应的行为。问题是，把这个叫做学习对不对呢？它是合适的词汇吗？把这称为智力对吗？甚至说它们有意识这是不是也对呢？这些植物神经生物学家中的一些相信植物有意识，不是自我意识，而是它们知道自己在空间里的位置并对此作出合适的反应，你瞧，石头就不行。所以，在我看来这问题变成了我们如何定义这些词汇：智力、学习、记忆。这是个科学问题也同样是一个哲学问题。我问过这些人什么是智力，因为，你知道，我与这些人相处的时间越久我对这个词的把握却越不确定，我试图查阅，却发现对智力的定义没有一致的看法……去维基百科查阅“智力”，他们也不能给出一个明晰的回答，只是一个基本的含有9种不同定义的图表。其中有约一半依赖于脑，涉及抽象推理或判断；另外约一半仅仅归结为问题解决能力。这也就是我们这里所谈的这种智力，这种解决问题的能力，对环境信号作出最佳反应。坦白地说，这不只局限于植物或动物，在细菌或其他微生物中可能也是适用的。因此，智力可能就如同这些人所提议的——是生命的一种性质，而不同生物之间的区别只是一个程度的问题，是程度的区别而不是种类的区别。我们人可能只是有更多的解决问题的能力，我们也可能用的是不同的方式。在不同的生命领域之间的连续性可能比我们通常所想的更广泛，在植物和动物之间的边界可能要比我们传统认为的更模糊一点。
(10m44s)
Plants can do incredible things. They do seem to remember stresses and events like in that experiment. They do have this ability to respond to fifteen to twenty environmental events in variable and process and behave accordingly. The issue is, is it right to call that learning? It that the right word? Is it right to call it intelligence? Is it right even to call what they are conscious? Some of these plant neurobiologists believe that plants are conscious, not self conscious but conscious in a sense of they know where they are in space, you know, which stone does not and react properly to their positions in space. And so to me it seems to come down to how we choose to define these words: intelligence, learning, memory. And that’s a philosophical question as much as is a scientific question. I would ask these people what is intelligence. Because, you know, my grasp on that word was getting more and more slippery the more time I spent with these people. And you try to look it up, and you would find that there is no agree upon definition of intelligence... But go to Wikipedia looking up intelligence they despair of giving you an answer, they just basically have a chart where they give you nine different definitions. And about half of them depend on a brain, you know, they refer to abstract reasoning or judgment; and the other half merely refer to a problem solving ability. And that’s the kind of intelligence that we are talking about here, the ability to solve problems, to react optimally to environmental signals. And that, frankly, is not limited to plants or animals, but it probably is true in bacteria and other microbes. So intelligence may well be as these people suggest a property of life and that, ah, difference from these (and?) other creatures maybe a matter of degree, a difference of degree rather than kind. That we just may have more of this problem solving ability and we may do in different ways. But that there is more continuity between the various kingdoms of life than we like to think and I think they are really for these people loud, the line between plants and animals might be a little softer than we traditionally think of that.
(5)
我发现很有意思的是，我了解到植物的情况越多就觉得我们自己也变的越神秘。例如，我们想不到比这更怪异的了：植物没有一个中央指挥机构却可以处理所有这些信息，而这是我们人的模型，因为我们有一个称为脑的中央指挥机构。不过如果你看看脑子本身，在那里没有指挥机构，脑中没有哪一个部分来掌管整个脑。它其实是一个网络。脑看起来与植物有很多相似之处。
(13m56s)
So what I found fascinating is the more I have learned about plants here the more mysteries we became. So for example, you know, we can’t think of weird that plants could process all this information without a central command post. Ah, that’s the model we have because we have central command post called our brains. But if you are looking in the brain itself there is no command post there. There is no there(?) there. There is no part of the brain that’s in charge of the whole brain. It’s a network, in fact. And the brains begin to look a lot like a plant.
(6)
对此的一个证据是植物对麻醉剂有反应。啊，这是个怪异的想法，你能用人的麻醉剂来麻醉一棵植物。还不只如此，植物生产它们自己的能麻醉我们的化合物。比如，植物在受伤时会产生乙烯（乙醚？）。突然，我意识到，这些是在提示植物生产麻醉剂是为了对付疼痛吗？
(16m53s)
And one of their bits of evidence for this is that plants respond to anesthetics. Ah, which is a weird idea, you can put a plant out with human anesthetic. And not only that, plants produce their own compounds that are anesthetic to us. Ethylene (ethylin?), for example, is produced by plants when they are injured. And suddenly, I realized are they suggesting that the plant produces anesthetic to deal with pain?
(7)
他的观点是，我们大部分人认为从进化的角度来看植物是古老的，它们比我们出现得早，所以我们还用从它们那儿学习吗？他说它们实际上很新。它们有如何建造、如何构想我们需要的东西的模型，因为，首先，它们在结构上是冗余的，没有脑子这有个大好处——当什么东西来吃你的时候你不会死，你能恢复。它们的建造是模块化的，它们反复地重复着自己的形态，它们是网络化的，它们是有冗余的，它们具有所有我们现在认为非常有恢复力（弹力）的特性，这是比如像万维网这些东西的基础。我们能向它们学习如何组织信息；我们能向它们学习恢复力的策略，这是不能从动物那里学到的。他还提议我们应该设计基于植物玩具而不是昆虫玩具原则的机器人。我们的机器人大都基于这种或那种的动物，为什么它们不能基于植物呢？我们或许最终能从植物那里得到更多。
(19m03s)
His point is most of us think plants are old in revolutionary terms. They predate us. So what we have to learn from them? He says they actually very new. And they have the model of how to build things, how to conceive things that we need because consider, first of all, they are redundant in their structure. It’s great not have a brain because when somebody eats you, you don’t die. You can comeback. They are modular in construction, they reiterated in their form, they are networked, ah, they are redundant, they have all these qualities that we now regard as incredibly resilient and are the basis for things like the World Wide Web. And that we can learn from how they organize information. And we can learn by their strategies for resilience in a way we can’t learn from animals. And he suggests we should design robots on the principle plant toys rather than insect toys and most of our robots are based on animals of one kind or another, why aren’t they based on plants? We might actually get more out of them.
(8)
杉树林中的树木是网络化的，它们处于一种非常复杂的网络之中，由真菌的菌丝连接在一起。菌根真菌在杉树林中连接所有的树。英属哥伦比亚大学的一位名叫苏珊-西马德的科学家对此作了研究，她向一棵杉树注射了放射性碳同位素，然后用盖革计数器和其他仪器追寻这些碳的踪迹……她的发现让人惊奇：所有的树相互联系着。它们用这个网络传递信息，比如说昆虫攻击的警告；它们用这个网络传送营养给它们的后代——它们能像动物一样认出它们的后代；它们甚至用这个网络与其他种类比如桦树进行营养品贸易。随着季节的变化杉树会在某个季节把多余的碳、糖送给桦树，到某个季节后再收回来。在地下有一套完整的经济活动在进行。
——《科学星期五》/《植物能思考吗？》，美国公共电台国际（PRI）2014/01/03
(20m16s)
The trees in the fir forest are networked, in a very complicated network, held together by the mycelium of the fungi – mycorrhizal fungi connect all the trees in a fir forest. And a scientist in (the University of) British Columbia named Suzanne Simard has studied this and she injects a fir tree with radio active carbon isotopes and then using a Geiger counter and other devices follows the trail of that carbon… and what she’s found is stunning. And all the trees are connected. They use that network to send information, such as warnings of an insect attack. They use that network to send nutrients to their offspring which they can favor; they recognize can like animals do. And they can even use that network to trade nutrients with other species such as birch trees. So that over the course of the season the fir tree will send the surplus carbon, sugars to the birch trees and then call in the debt. There is a whole economy going on under the soil.
-- Science Friday / Can Plants Think? PRI 2014/01/03
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