科学美国人60秒 科学终于解释了口吃原因（在线收听）

科学终于解释了口吃原因

Karen Hopkin: This is Scientific American’s 60-Second Science. I’m Karen Hopkin.

Hopkin: When you stop to think about it, it’s not all that easy to speak. First you have to think of something to say. Then your brain has to tell your mouth to say it.

Interruptions anywhere along this articulation pathway can impair the utterance, and create something like a stutter.

凯伦霍普金：这是《科学美国人》的 60 秒科学。我是凯伦霍普金。

霍普金：当你停下来想一想时，说起来并不是那么容易。首先，你必须想好要说的话。然后你的大脑必须告诉你的嘴说出来。沿着这个发音路径的任何地方中断都会损害话语，并产生类似口吃的东西。

Now, studying a neurocomputational model of this complex process, researchers have found that stuttering stems from a glitch in the neural circuit that initiates speech. They presented their findings at the Meeting of the Acoustical Society of America. [F. Guenther et al., Stuttering Starts at Speech Initiation, Not Due to Impaired Motor Skills]

现在，研究人员研究了这一复杂过程的神经计算模型，发现口吃源于启动语音的神经回路中的故障。他们在美国声学学会会议上展示了他们的发现。

Frank Guenther: My main research interest is translating how the brain translates thoughts ...

Frank Guenther：我的主要研究兴趣是翻译大脑如何翻译思想......

Hopkin: Frank Guenther of Boston University.

Guenther: ... into movements of the tongue and the other speech articulators that convey these thoughts to another person.

Hopkin: He says that stuttering is very common and it happens in all languages. It’s estimated that about one percent of the world’s population stutters.

霍普金：波士顿大学的 Frank Guenther。

Guenther：……进入将这些想法传达给另一个人的舌头和其他发音器官的运动。

霍普金：他说口吃很常见，所有语言都有。据估计，世界上约有百分之一的人口口吃。

Guenther: Despite this, and despite being studied at least as far back as the ancient Romans, our understanding of what causes stuttering has been until recent years very poor.

Hopkin: Numerous neural circuits come into play when it comes to generating speech. But the key drivers can be broken down into two main circuits.

Guenther：尽管如此，尽管至少可以追溯到古罗马人的研究，但直到最近几年，我们对导致口吃的理解仍然非常贫乏。

霍普金：在生成语音时，许多神经回路都会发挥作用。 但关键驱动因素可以分解为两个主要电路。

Guenther: One is an initiation circuit and the other is an articulation circuit. To understand the function of these circuits it’s useful to consider something like the energizer bunny which has an on/off switch as well as a set of motors and gears that make the bunny walk and play drums when the switch is turned on.

Guenther：一个是启动电路，另一个是关节电路。 要了解这些电路的功能，可以考虑一下像激励兔子这样的东西，它有一个开/关开关以及一组电机和齿轮，当开关打开时，这些电机和齿轮可以让兔子走路和打鼓。

Hopkin: The on/off switch initiates the movement. And the motors and gears make it happen. But which of these circuits can lead to a stutter? To find out, Guenther pieced together equations that represent how the neurons that form these circuits interact.

霍普金：开/关开关启动运动。 电机和齿轮使它成为现实。 但是这些电路中的哪一个会导致口吃？ 为了找出答案，Guenther 拼凑了代表形成这些回路的神经元如何相互作用的方程式。

Guenther: These equations describe neural activity in different parts of the brain including the basal ganglia, cerebellum, and the cerebral cortex.

Guenther：这些方程描述了大脑不同部分的神经活动，包括基底神经节、小脑和大脑皮层。

Hopkin: One set of equations represents the electrical activity of the neurons in all of these regions…another the strength of the connections they form with each other. That allows Guenther and his team to experimentally manipulate various aspects of the system.

霍普金：一组方程代表所有这些区域中神经元的电活动……另一组代表它们彼此形成的连接强度。 这使 Guenther 和他的团队能够通过实验操作该系统的各个方面。

Guenther:  And it allows us to test different versions of the story regarding the basal ganglia’s involvement in stuttering by basically impairing different parts of the circuit and observing what happens in terms of speech output and also brain activity.

Guenther：它允许我们通过基本上削弱电路的不同部分并观察在语音输出和大脑活动方面发生的情况来测试关于基底神经节参与口吃的不同版本的故事。

Hopkin: The basal ganglia, structures tucked beneath the brain’s cerebral cortex, play a critical role in initiating a variety of motor activities.

Guenther: They basically monitor our thoughts sensations and actions and they determine which actions we should perform next.

Hopkin: That includes the muscles involved in speech.

[audio] Good doggie.

霍普金：基底神经节是隐藏在大脑大脑皮层下方的结构，在启动各种运动活动中起着关键作用。

Guenther：他们基本上监控我们的思想感觉和行动，并确定我们接下来应该执行哪些行动。

霍普金：这包括与说话有关的肌肉。

[音频] 好小狗。

Hopkin: That’s an example of the speech that comes from Guenther’s computational model when everything is working as it should. But then Guenther fiddles with the equations in the initiation circuit…reducing the connections here or boosting the stimulation there. Which produces what sounds like a typical stutter.

[audio] Guh-g-g-good doggie.

Hopkin: That says to Guenther…

霍普金：这是一个来自 Guenther 计算模型的演讲的例子，当一切都按预期工作时。 但随后 Guenther 摆弄了启动电路中的方程式……减少此处的连接或增强那里的刺激。 这会产生听起来像典型的口吃。

[音频] Guh-g-g-good 小狗。

霍普金：这对Guenther 说……

Guenther: …stuttering is a problem with the on/off switch. The motors and gears work fine. But the switch doesn’t always turn on when it should. Or it doesn’t stay on as long as it should. This results in delays in initiating a word. Or repetitions of the first part of the word.

[audio] Guh-guh-good doggie.

Guenther：……口吃是开/关开关的问题。 电机和齿轮工作正常。 但是开关并不总是在应该打开的时候打开。 或者它不会保持应有的时间。 这会导致启动单词的延迟。 或单词第一部分的重复。

[音频] Guh-guh-good 小狗。

Guenther: …and these are the behaviors that we refer to as stuttering.

Guenther：……这些就是我们所说的口吃行为。

Hopkin: Having a computer model allows Guenther to test out different hypotheses for why the initiation circuit fails…whether, for example, it’s an overabundance of activation or a degradation of neuronal signaling. Guenther says he’d like to combine his model with imaging studies that show the basal ganglia in action…to see whether his predicted mechanisms play a role in people who stutter. The ultimate goal is to come up with precisely targeted treatments…like drugs that tweak the activity of the basal ganglia without inducing serious side effects…

霍普金：拥有一个计算机模型可以让 Guenther 测试启动电路为何失败的不同假设……例如，它是过度激活还是神经元信号传导退化。 Guenther 说他想将他的模型与显示基底神经节活动的成像研究结合起来……看看他预测的机制是否对口吃的人起作用。 最终目标是提出精确靶向治疗……比如调整基底神经节活动而不引起严重副作用的药物……

Guenther: Or possibly even implanted electrodes that modulate activity in particular parts of the basal ganglia circuit.

Hopkin: Which should make your basal ganglia as good as that…

[audio] … doggie

Hopkin: For Scientific American’s 60-Second Science, I’m Karen Hopkin.

Guenther：或者甚至可能植入电极，调节基底神经节回路特定部分的活动。

霍普金：哪一个能让你的基底神经节这么好……

[音频] ...小狗

霍普金：对于《科学美国人》的 60 秒科学，我是凯伦霍普金。