你所看到的有多少是幻觉？ - 伊丽莎白·考克斯 (Elizabeth Cox)：英语精读讲义

An elderly woman named Rosalie was sitting in her nursing home when her room suddenly burst to life with twirling fabrics. 講解

一位名叫罗莎莉的老妇人正坐在她的养老院里，这时她的房间突然充满了旋转的织物。

Through the elaborate drapings, she could make out animals, children, and costumed characters. 短語動詞

穿过精美的帷幔，她能辨认出动物、儿童和盛装打扮的人。

Rosalie was alarmed,

罗莎莉感到惊恐，

not by the intrusion, 語法

不是因为这种闯入，

but because she knew this entourage was an extremely detailed hallucination. 用詞

而是因为她知道这群出现的事物是一个极其精细的幻觉。

Her cognitive function was excellent, 用詞

她的认知功能极好，

and she had not taken any medications that might cause hallucinations. 語法

而且她没有服用任何可能引起幻觉的药物。

Strangest of all, 表達脈絡

最奇怪的是，

had a real-life crowd of circus performers burst into her room, 語法

就算有一大群真正的马戏团表演者冲进她的房间，

she wouldn't have been able to see them.

她也根本看不见他们。

She was completely blind.

她已经完全失明了。

Rosalie had developed a condition known as Charles Bonnet Syndrome, 講解

罗莎莉患上了一种被称为查尔斯·邦奈综合征的疾病，

in which patients with either impaired vision or total blindness 語法

在这种疾病中，视力受损或完全失明的患者

suddenly hallucinate whole scenes in vivid color. 短語搭配

会突然产生色彩鲜艳的整个场景的幻觉。

These hallucinations appear suddenly and can last for mere minutes or recur for years. 短語搭配

这些幻觉突然出现，可能只持续几分钟，也可能反复出现数年。

We still don't fully understand what causes them to come and go 短語搭配

我们仍未完全弄懂是什么导致它们来去不定，

or why certain patients develop them when others don't. 語法

以及为什么有些患者会出现，而另一些则不会。

We do know from fMRI studies that these hallucinations activate the same brain areas as sight, 講解

我们从功能性磁共振成像（fMRI）研究中确实知道，这些幻觉激活了与视觉相同的大脑区域，

areas that are not activated by imagination.

也就是那些不会被想象力激活的区域。

Many other hallucinations,

许多其他幻觉，

including smells, sights, and sounds,

包括嗅觉、视觉和听觉，

also involve the same brain areas as real sensory experiences.

也同样涉及与真实感官体验相同的大脑区域。

Because of this, 表達脈絡

正因为如此，

the cerebral cortex is thought to play a part in hallucinations. 短語搭配

人们认为大脑皮层在幻觉中起着一定作用。

This thin layer of gray matter covers the entire cerebrum, 用詞

这层薄薄的灰质覆盖了整个大脑皮层，

with different areas processing information from each of our senses. 語法

不同的区域负责处理来自我们每种感官的信息。

But even in people with completely unimpaired senses, 表達脈絡

但即使是感官完全无损的人，

the brain constructs the world we perceive from incomplete information. 用詞

大脑也是利用不完整的信息来构建我们感知的世界的。

For example,

例如，

our eyes have blind spots where the optic nerve blocks part of the retina. 用詞

我们的眼睛有盲点，这是因为视神经遮挡了部分视网膜。

When the visual cortex processes light into coherent images, 短語搭配

当视觉皮层将光线处理成连贯的图像时，

it fills in these blind spots with information from the surrounding area. 短語動詞

它会用周围区域的信息来填补这些盲点。

Occasionally,

偶尔，

we might notice a glitch,

我们可能会注意到一些视觉差错，

but most of the time we're none the wiser. 習語

但大多数时候我们都毫无察觉。

When the visual cortex is deprived of input from the eyes, 短語搭配

当视觉皮层无法接收来自眼睛的输入时，

even temporarily,

哪怕只是暂时的，

the brain still tries to create a coherent picture,

大脑仍会试图创造出一幅连贯的画面，

but the limits of its abilities become a lot more obvious.

但其能力的极限就会变得明显得多。

The full-blown hallucinations of Charles Bonnet Syndrome are one example. 用詞

查尔斯·邦奈综合征中成熟的幻觉就是一个例子。

Because Charles Bonnet Syndrome only occurs in people who had normal vision and then lost their sight, 語法

因为查尔斯·邦奈综合征只发生在过去视力正常后来失明的人身上，

not those who were born blind,

而不会发生在天生失明的人身上，

scientists think the brain uses remembered images to compensate for the lack of new visual input. 短語搭配

科学家们认为，大脑是利用记忆中的图像来弥补缺乏新视觉输入的问题。

And the same is true for other senses. 短語搭配

对于其他感官也是如此。

People with hearing loss often hallucinate music or voices,

听力受损的人经常会产生音乐或人声的幻觉，

sometimes as elaborate as the cacophony of an entire marching band. 講解

有时甚至复杂到像是整个军乐队在演奏时发出的嘈杂声。

In addition to sensory deprivation, 表達脈絡

除了感官剥夺之外，

recreational and therapeutic drugs, 用詞

娱乐性和治疗性药物、

conditions like epilepsy and narcolepsy,

癫痫和嗜睡症等疾病，

and psychiatric disorders like schizophrenia,

以及精神分裂症等精神障碍，

are a few of the many known causes of hallucinations, 表達脈絡

只是已知会引起幻觉的众多原因中的一小部分，

and we're still finding new ones.

而且我们还在不断发现新的原因。

Some of the most notorious hallucinations are associated with drugs like LSD and psilocybin. 講解

一些最臭名昭著的幻觉与 LSD 和裸盖菇素等药物有关。

Their hallmark effects include the sensation that dry objects are wet 講解

它们标志性的作用包括让人感觉干燥的物体是湿的，

and that surfaces are breathing.

以及表面在呼吸。

At higher doses,

在剂量较高时，

the visual world can appear to melt, 短語搭配

视觉世界可能会显得像在融化、

dissolve into swirls, 短語搭配

溶解成漩涡，

or burst into fractal-like patterns. 短語搭配

或者爆发出类似分形的图案。

Evidence suggests these drugs also act on the cerebral cortex. 表達脈絡

有证据表明这些药物也会作用于大脑皮层。

But while visual impairment typically only causes visual hallucinations 表達脈絡

但是，视力受损通常只引起视觉幻觉，

and hearing loss auditory ones, 語法

听力受损引起听觉幻觉，

substances like LSD cause perceptual disturbances across all the senses. 短語搭配

而 LSD 这类物质则会引起所有感官的知觉障碍。

That's likely because they activate receptors in a broad range of brain areas, 短語搭配

这可能是因为它们激活了大脑各个区域的受体，

including the cortical regions for all the senses.

包括所有感官的皮层区域。

LSD and psilocybin both function like serotonin in the brain, 用詞

LSD 和裸盖菇素在大脑中的作用都类似血清素，

binding directly to one type of serotonin receptor in particular. 短語搭配

特别是直接与一种类型的血清素受体结合。

While serotonin's role in the brain is complex and poorly understood, 表達脈絡

尽管血清素在大脑中的作用很复杂，且人们对其知之甚少，

it likely plays an important part in integrating information from the eyes, 用詞

但它可能在整合来自眼睛、

nose, ears, and other sensory organs.

鼻子、耳朵和其他感觉器官的信息方面起着重要作用。

So one theory is that LSD and psilocybin cause hallucinations by disrupting the signaling involved in sensory integration. 講解

因此有一种理论认为，LSD 和裸盖菇素是通过破坏感觉整合所涉及的信号传导来引发幻觉的。

Hallucinations associated with schizophrenia may share a similar mechanism with those caused by LSD and psilocybin. 短語搭配

与精神分裂症相关的幻觉可能与 LSD 和裸盖菇素引起的幻觉有着相似的机制。

Patients with schizophrenia often have elevated levels of serotonin in the brain, 短語搭配

精神分裂症患者大脑中的血清素水平通常较高，

and antipsychotic drugs relieve symptoms of schizophrenia by blocking the same serotonin receptors LSD and psilocybin bind to. 講解

而抗精神病药物通过阻断 LSD 和裸盖菇素所结合的同类血清素受体，来缓解精神分裂症的症状。

And in some cases,

在某些情况下，

these drugs can even relieve the hallucinations of patients with Charles Bonnet Syndrome.

这些药物甚至可以缓解查尔斯·邦奈综合征患者的幻觉。

We're still a long way from understanding all the different causes and interconnected mechanisms of hallucinations, 短語搭配

我们距离了解幻觉的所有不同原因和相互关联的机制还有很长的路要走，

but it's clear that hallucinatory experiences are much more closely tied to ordinary perception than we once thought. 短語搭配

但显而易见的是，幻觉体验与普通感知的联系，比我们曾经认为的要紧密得多。

And by studying hallucinations,

通过研究幻觉，

we stand to learn a great deal about how our brains construct the world we see, 短語搭配

我们大有机会深入了解我们的大脑是如何构建我们所看到、

hear, smell, and touch.

听到、闻到和触摸到的这个世界的。

As we learn more,

随着了解的加深，

we'll likely come to appreciate just how subjective and individual each person's island universe of perception really is. 講解

我们也许能渐渐体会到每个人感知宇宙中的孤岛到底有多主观、多独特。

Want to keep exploring this subject?

想继续探索这个主题吗？

We recommend Oliver Sacks's Hallucinations. 文化背景

我们推荐奥利弗·萨克斯的《幻觉》。

This book includes jaw-dropping personal accounts of a range of sensory disturbances, 用詞

这本书包含了一系列令人瞠目结舌的感官障碍的个人自述，

including mysterious voices,

其中包括神秘的声音、

non-existent visitors,

不存在的访客，

and even Kermit the Frog. 文化背景

甚至还有科米蛙。

You can download an audiobook version for free at audible.com/ted-ed.

你可以在 audible.com/teded 免费下载有声书版本。