你所看到的有多少是幻覺？ - 伊麗莎白·考克斯 (Elizabeth Cox)：英語精讀講義

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

一位名叫羅莎莉的老婦人正坐在她的安養院裡，這時她的房間突然充滿了旋轉的織物。

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

穿過精美的帷幔，她能辨認出動物、兒童和盛裝打扮的人。

Rosalie was alarmed,

羅莎莉感到驚恐，

not by the intrusion, 文法

不是因為這種闖入，

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

而是因為她知道這群出現的事物是一個極其精細的幻覺。

Her cognitive function was excellent, 用詞

她的認知功能極好，

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

而且她沒有服用任何可能引起幻覺的藥物。

Strangest of all, 表達脈絡

最奇怪的是，

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

就算有一大群真正的馬戲團表演者衝進她的房間，

she wouldn't have been able to see them.

她也根本看不見他們。

She was completely blind.

她已經完全失明了。

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

羅莎莉患上了一種被稱為查爾斯·邦奈症候群的疾病，

in which patients with either impaired vision or total blindness 文法

在這種疾病中，視力受損或完全失明的患者

suddenly hallucinate whole scenes in vivid color. 片語搭配

會突然產生色彩鮮豔的整個場景的幻覺。

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

這些幻覺突然出現，可能只持續幾分鐘，也可能反覆出現數年。

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

我們仍未完全弄懂是什麼導致它們來去不定，

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

以及為什麼有些患者會出現，而另一些則不會。

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

我們從功能性磁振造影（fMRI）研究中確實知道，這些幻覺激活了與視覺相同的大腦區域，

areas that are not activated by imagination.

也就是那些不會被想像力激活的區域。

Many other hallucinations,

許多其他幻覺，

including smells, sights, and sounds,

包括嗅覺、視覺和聽覺，

also involve the same brain areas as real sensory experiences.

也同樣涉及與真實感官體驗相同的大腦區域。

Because of this, 表達脈絡

正因為如此，

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

人們認為大腦皮層在幻覺中起著一定作用。

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

這層薄薄的灰質覆蓋了整個大腦半球，

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

不同的區域負責處理來自我們每種感官的信息。

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

但即使是感官完全無損的人，

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

大腦也是利用不完整的信息來構建我們感知的世界的。

For example,

例如，

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

我們的眼睛有盲點，這是因為視神經遮擋了部分視網膜。

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

當視覺皮層將光線處理成連貫的圖像時，

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

它會用周圍區域的信息來填補這些盲點。

Occasionally,

偶爾，

we might notice a glitch,

我們可能會注意到一些視覺差錯，

but most of the time we're none the wiser. 慣用語

但大多數時候我們都毫無察覺。

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

當視覺皮層無法接收來自眼睛的輸入時，

even temporarily,

哪怕只是暫時的，

the brain still tries to create a coherent picture,

大腦仍會試圖創造出一幅連貫的畫面，

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

但其能力的極限就會變得明顯得多。

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

查爾斯·邦奈症候群中成熟的幻覺就是一個例子。

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

因為查爾斯·邦奈症候群只發生在過去視力正常後來失明的人身上，

not those who were born blind,

而不會發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. 片語搭配

科學家們認為，大腦是利用記憶中的圖像來彌補缺乏新視覺輸入的問題。

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

對於其他感官也是如此。

People with hearing loss often hallucinate music or voices,

聽力受損的人經常會產生音樂或人聲的幻覺，

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

有時甚至複雜到像是整個軍樂隊在演奏時發出的嘈雜聲。

In addition to sensory deprivation, 表達脈絡

除了感官剝奪之外，

recreational and therapeutic drugs, 用詞

娛樂性和治療性藥物、

conditions like epilepsy and narcolepsy,

癲癇和嗜睡症等疾病，

and psychiatric disorders like schizophrenia,

以及思覺失調症等精神障礙，

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

只是已知會引起幻覺的眾多原因中的一小部分，

and we're still finding new ones.

而且我們還在不斷發現新的原因。

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覺與 LSD 和裸蓋菇素等藥物有關。

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

它們標誌性的作用包括讓人感覺乾燥的物體是濕的，

and that surfaces are breathing.

以及表面在呼吸。

At higher doses,

在劑量較高時，

the visual world can appear to melt, 片語搭配

視覺世界可能會顯得像在融化、

dissolve into swirls, 片語搭配

溶解成漩渦，

or burst into fractal-like patterns. 片語搭配

或者爆發出類似碎形的圖案。

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

有證據表明這些藥物也會作用於大腦皮層。

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

但是，視力受損通常只引起視覺幻覺，

and hearing loss auditory ones, 文法

聽力受損引起聽覺幻覺，

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

而 LSD 這類物質則會引起所有感官的知覺障礙。

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

這可能是因為它們激活了大腦各個區域的受體，

including the cortical regions for all the senses.

包括所有感官的皮層區域。

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

LSD 和裸蓋菇素在大腦中的作用都類似血清素，

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

特別是直接與一種類型的血清素受體結合。

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

儘管血清素在大腦中的作用很複雜，且人們對其知之甚少，

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

但它可能在整合來自眼睛、

nose, ears, and other sensory organs.

鼻子、耳朵和其他感覺器官的信息方面起著重要作用。

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

因此有一種理論認為，LSD 和裸蓋菇素是通過破壞感覺整合所涉及的信號傳導來引發幻覺的。

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

與思覺失調症相關的幻覺可能與 LSD 和裸蓋菇素引起的幻覺有著相似的機制。

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

思覺失調症患者大腦中的血清素水平通常較高，

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

而抗精神病藥物通過阻斷 LSD 和裸蓋菇素所結合的同類血清素受體，來緩解思覺失調症的症狀。

And in some cases,

在某些情況下，

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

這些藥物甚至可以緩解查爾斯·邦奈症候群患者的幻覺。

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

我們距離了解幻覺的所有不同原因和相互關聯的機制還有很長的路要走，

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

但顯而易見的是，幻覺體驗與普通感知的聯繫，比我們曾經認為的要緊密得多。

And by studying hallucinations,

通過研究幻覺，

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

我們大有機會深入了解我們的大腦是如何構建我們所看到、

hear, smell, and touch.

聽到、聞到和觸摸到的這個世界的。

As we learn more,

隨著了解的加深，

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

我們也許能漸漸體會到每個人感知宇宙中的孤島到底有多主觀、多獨特。

Want to keep exploring this subject?

想繼續探索這個主題嗎？

We recommend Oliver Sacks's Hallucinations. 文化背景

我們推薦奧利佛·薩克斯的《幻覺》。

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

這本書包含了一系列令人瞠目結舌的感官障礙的個人自述，

including mysterious voices,

其中包括神秘的聲音、

non-existent visitors,

不存在的訪客，

and even Kermit the Frog. 文化背景

甚至還有科米蛙。

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

你可以在 audible.com/teded 免費下載有聲書版本。