不用眼睛也能“看”？科学家在猴脑中“注入”信息

When you drive toward an intersection, the sight of the light turning red will (or should) make you step on the brake. This action happens thanks to a chain of events inside your head.

当你开车经过一个十字路口时，看到了变红的指示灯，你会（或你应该）踩下刹车。能做出这个动作多亏了你大脑中的一系列反应。

Your eyes relay signals to the visual centers in the back of your brain. After those signals get processed, they travel along a pathway to another region, the premotor cortex, where the brain plans movements.

你的眼睛会向大脑后部的视觉中枢传递信号。经过处理后的信号将沿着一条通路到达一个叫做前运动皮层的区域，大脑便在这个区域安排运动。

Now, imagine that you had a device implanted in your brain that could shortcut the pathway and “inject” information straight into your premotor cortex.

现在，试想一下在你的大脑中植入一个可以绕过通路走捷径、将信息直接“注入”前运动皮层的装置。

That may sound like an outtake from “The Matrix.” But now two neuroscientists at the University of Rochester say they have managed to introduce information directly into the premotor cortex of monkeys. The researchers published the results of the experiment on Thursday in the journal Neuron.

这听起来或许像是《黑客帝国》(The Matrix)中的一幕。但现在已有两名来自罗切斯特大学(University of Rochester)的神经学家在猴子的大脑中做到了使信息直接进入前运动皮层。周四，《神经元》(Neuron)期刊发表了科学家的实验结果。

Although the research is preliminary, carried out in just two monkeys, the researchers speculated that further research might lead to brain implants for people with strokes.

尽管这只是初步的研究，仅对两只猴子进行了实验，但研究人员推测，更深入的研究或将用来为中风患者做大脑植入手术。

“You could potentially bypass the damaged areas and deliver stimulation to the premotor cortex,” said Kevin A. Mazurek, a co-author of the study. “That could be a way to bridge parts of the brain that can no longer communicate.”

“也许可以绕开受损区域，将刺激信号输送至前运动皮层，”该研究的一位共同作者凯文.A.马祖雷克(Kevin A. Mazurek)说。“用这个办法可以连通大脑中已经无法联系上的区域。”

In order to study the premotor cortex, Dr. Mazurek and his co-author, Dr. Marc H. Schieber, trained two rhesus monkeys to play a game.

为了研究前运动皮层，马祖雷克和他的共同作者马克.H.希贝尔博士(Dr. Marc H. Schieber)训练两只恒河猴来玩一种游戏。

The monkeys sat in front of a panel equipped with a button, a sphere-shaped knob, a cylindrical knob, and a T-shaped handle. Each object was ringed by LED lights. If the lights around an object switched on, the monkeys had to reach out their hand to it to get a reward — in this case, a refreshing squirt of water.

猴子要坐在一个控制板前，控制板上有一个按钮，一个球形把手、一个圆柱形把手和一个T字型手柄。每个手柄都有LED灯环绕。如果该对象周围的LED灯亮起，猴子需要向着该对象伸出手才可以得到奖赏-在本研究中，奖赏是会喷出清凉的水。

Each object required a particular action. If the button glowed, the monkeys had to push it. If the sphere glowed, they had to turn it. If the T-shaped handle or cylinder lit up, they had to pull it.

每个对象都需要做出特定的动作。如果是按钮亮起，猴子需要按下按钮。如果是球形把手亮起，则需要转动把手。如果是T字型手柄或圆柱形把手亮起，猴子需要拉动把手。

After the monkeys learned how to play the game, Dr. Mazurek and Dr. Schieber had them play a wired version. The scientists placed 16 electrodes in each monkey’s brain, in the premotor cortex.

在猴子学会了如何玩之后，马祖雷克和希贝尔让它们玩了一个接线版本。科学家们在每个猴子大脑的前运动皮层放置了16个电极。

Each time a ring of lights switched on, the electrodes transmitted a short, faint burst of electricity. The patterns varied according to which object the researchers wanted the monkeys to manipulate.

每一次有一圈灯光亮起，电极就会传递一股短暂而微弱的电流。电流的模式会根据科学家们希望猴子去操控的不同物品有所改变。

As the monkeys played more rounds of the game, the rings of light dimmed. At first, the dimming caused the monkeys to make mistakes. But then their performance improved.

猴子玩了几轮下来，手柄周围的灯光会被调暗。起初，暗下来的灯光会使猴子犯错。但他们的表现会有所改善。

Eventually the lights went out completely, yet the monkeys were able to use only the signals from the electrodes in their brains to pick the right object and manipulate it for the reward. And they did just as well as with the lights.

最后，灯光会被完全熄灭，但猴子们仍能单纯依靠电极向大脑传输的信号挑选并操纵正确的对象从而获得奖励。并且表现得和有灯光时一样好。

This hints that the sensory regions of the brain, which process information from the environment, can be bypassed altogether. The brain can devise a response by receiving information directly, via electrodes.

这就意味着大脑中处理环境信息的感觉区是可以被完全绕过的。大脑可以通过电极直接接收信息，作出反应。

Neurologists have long known that applying electric current to certain parts of the brain can make people involuntarily jerk certain parts of their bodies. But this is not what the monkeys were experiencing.

神经学家早就知道，在大脑特定部位使用电流，可以使人身体的某些部位不由自主地抽动。但这与猴子们所体验的不同。

Dr. Mazurek and Dr. Schieber were able to rule out this possibility by seeing how short they could make the pulses. With a jolt as brief as a fifth of a second, the monkeys could still master the game without lights. Such a pulse was too short to cause the monkeys to jerk about.

马祖雷克和希贝尔通过将脉冲时间缩至最短，排除了这一可能。虽然冲击仅有五分之一秒，猴子依然能够出色地在没有灯光的时候完成游戏。如此短暂的脉冲也不足以让猴子作出抽搐反应。

“The stimulation must be producing some conscious perception,” said Paul Cheney, a neurophysiologist at the University of Kansas Medical Center, who was not involved in the new study.

“刺激肯定是造成了一些有意识的感知，”堪萨斯大学医学中心(University of Kansas Medical Center)的神经学家保罗.切尼(Paul Cheney)说，他并未参与本次新实验。

But what exactly is that something? It’s hard to say. “After all, you can’t easily ask the monkey to tell you what they have experienced,” Dr. Cheney said.

但究竟是些什么感知？还不好说。“毕竟，你不能直接去问猴子们是什么感觉，”切尼说道。

Dr. Schieber speculated that the monkeys “might feel something on their skin. Or they might see something. Who knows what?”

希贝尔猜测，猴子们“或许能感受到皮肤上有些什么。或者他们能看见什么。谁知道是什么呢？”

What makes the finding particularly intriguing is that the signals the scientists delivered into the monkey brains had no underlying connection to the knob, the button, the handle or the cylinder.

使这个发现格外有趣的是，科学家们输送到猴子大脑中的信号，与按钮、把手、手柄或圆柱体都没有潜在联系。

Once the monkeys started using the signals to grab the right objects, the researchers shuffled them into new assignments. Now different electrodes fired for different objects — and the monkeys quickly learned the new rules.

一旦猴子们开始根据这些信号去抓取正确的物品，研究人员就给它们安排新的任务。现在，将不同的电极对应不同的物品，猴子们很快就学会了新规则。

“This is not a prewired part of the brain for built-in movements, but a learning engine,” said Michael A. Graziano, a neuroscientist at Princeton University who was not involved in the study.

“这并不是大脑预置的固有运动的一部分，而是一个学习引擎，”普林斯顿大学(Princeton University)的神经学家迈克尔.A.格拉齐亚诺(Michael A. Graziano)说。他没有参与这项研究。

Dr. Mazurek and Dr. Schieber only implanted small arrays of electrodes into the monkeys. Engineers are working on implantable arrays that might include as many as 1,000 electrodes. So it may be possible one day to transmit far more complex packages of information into the premotor cortex.

马祖雷克和希贝尔只往猴子体内植入了很小的电极阵列。工程师们正在研究可能包括多达1000个电极的可植入阵列。所以，将来也许可以将复杂得多的信息包传递到前运动皮层。

Dr. Schieber speculated that someday scientists might be able to use such advanced electrodes to help people who suffer brain damage. Strokes, for instance, can destroy parts of the brain along the pathway from sensory regions to areas where the brain makes decisions and sends out commands to the body.

希贝尔预计，将来，科学家们也许能够使用这种先进的电极来帮助那些脑部受损的人。例如，大脑中从感觉区域通向大脑做出决定、并向身体发出指令的区域的路径中，某些部分可能会因中风被破坏。

Implanted electrodes might eavesdrop on neurons in healthy regions, such as the visual cortex, and then forward information into the premotor cortex.

植入电极可以窃听健康区域的神经元，比如视觉皮层，然后将信息转发到前运动皮层。

“When the computer says, ‘You’re seeing the red light,’ you could say, ‘Oh, I know what that means — I’m supposed to put my foot on the brake,’” said Dr. Schieber. “You take information from one good part of the brain and inject it into a downstream area that tells you what to do.”

“当电脑说，‘当你看到红灯时’，你可以说，‘哦，我知道那是什么意思-我应该把脚踩在刹车上，’”希贝尔说。“你从大脑的一个健康区域获得信息，把它发送至给身体下达指令的下游区域。”