Name: 【TED-Ed】看到神秘的東西 ... 什麼會造成幻覺？(What causes hallucinations? - Elizabeth Cox)
Uploaded: 2018-10-07T21:01:30.000Z
Duration: 5 min 50 s

An elderly woman named Rosalie was sitting in her nursing home

一位名叫 Rosalie 的老太太坐在養老院裡

when her room suddenly burst to life with twirling fabrics.

她的房間突然出現舞動的結構，像是有了生命

Rosalie was alarmed, not by the intrusion,

Rosalie 感到驚慌，但不是因為覺得被入侵

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

而是她知道這個環境是一個充滿細節的幻覺

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

她沒有服用任何可能引起幻覺的藥物

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

最奇怪的是，一個現實生活中的馬戲團演員闖進了她的房間

Rosalie had developed a condition known as Charles Bonnet Syndrome,

Rosalie 得了一種名為邦納症候群的病症

in which patients with either impaired  vision or total blindness

其中視力受損或完全失明的患者

suddenly hallucinate whole scenes  in vivid color.

突然把整個場景幻化成鮮明的色彩

and can last for mere minutes or recur for years.

而且可以持續短短幾分鐘或復發多年

We still don't fully understand what causes them to come and go,

我們還不能完全知道是什麼原因促使症狀反覆發生

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

或是為什麼特定病患會有幻覺，而其他人卻沒有

We do know from fMRI studies that these hallucinations

但我們知道功能性磁共振成像研究出這些幻覺

areas that are not activated  by imagination.

Many other hallucinations, including smells,

also involve the same brain areas as real sensory experiences.

也涉及到與真實感官體驗相同的大腦區域

Because of this, the cerebral cortex is thought to play a part in hallucinations.

因此，大腦皮層被認為是幻覺的一部分

This thin layer of grey matter covers the entire cerebrum,

with different areas processing  information from each of our senses.

用不同的區域處理來自我們每個感官的資訊

But even in people with completely unimpaired senses,

the brain constructs the world we perceive from incomplete information.

大腦構建我們從不完整資訊中感知的世界

where the optic nerve blocks part of the retina.

When the visual cortex processes light into coherent images,

當視覺皮層將光處理成連貫的影像

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

它利用周圍地區的資訊填補這些盲點

Occasionally, we might notice a glitch, but most of the time we're none the wiser.

偶爾，我們可能會注意到一個小故障，但大部分時間我們都不知道

When the visual cortex is deprived of input from the eyes, even temporarily,

當眼睛剝奪視覺皮層看到的畫面，即使是暫時的

the brain still tries to create a coherent picture,

大腦仍然會試著創造出連貫的影像

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

但其能力的局限性變得更加明顯

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

邦納症候群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,

原本視力正常，但後來失明的人身上

scientists think the brain uses remembered images

科學家認為大腦使用記憶的影像

to compensate for the lack of new visual input.

People with hearing loss often hallucinate music or voices,

失聰的人常常幻聽到音樂或聲音

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

有時像整個行進樂團的雜音一樣精細

and psychiatric disorders like schizophrenia,

are a few of the many known causes of hallucinations,

是許多已知的幻覺原因中的一部分

Some of the most notorious hallucinations

are associated with drugs like LSD and psilocybin.

與藥物如 LSD (迷幻藥) 和裸蓋菇素有關

Their hallmark effects include the sensation that dry objects are wet

他們的效果特徵包括感覺到乾燥物體是濕的

At higher doses, the visual world can appear to melt,

在更高的劑量下，視覺世界可能會融化

Evidence suggests these drugs also act on the cerebral cortex.

有證據表明這些藥物也對大腦皮層起作用

But while visual impairment typically  only causes visual hallucinations,

但是視覺損傷通常只會引起視覺幻覺

substances like LSD cause perceptual disturbances across all the senses.

像 LSD 這樣的物質會引起所有感官的知覺干擾

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

這很可能是因為它們刺激了腦區廣泛的受體

including the cortical regions for all the senses.

LSD and psilocybin both function like serotonin in the brain,

LSD 和裸蓋菇素都像大腦中的血清素

binding directly to one type of serotonin receptor in particular.

特別是直接與一種血清素受體結合

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

而大腦中的血清素很複雜且知之甚少

it likely plays an important part in integrating information

它可能在整合資訊方面有重要的作用

So one theory is that LSD and psilocybin cause hallucinations

有一種理論認為，LSD 和裸蓋菇素會引起幻覺

by disrupting the signaling  involved in sensory integration.

Hallucinations associated with schizophrenia

may share a similar mechanism with those caused by LSD and psilocybin.

可能與 LSD 和裸蓋菇素引起相同的幻覺

often have elevated levels of serotonin in the brain.

他們大腦中的血清素水準常常升高

And antipsychotic drugs relieve symptoms of schizophrenia

而抗精神病藥物緩解精神分裂症的症狀

by blocking the same serotonin receptors LSD and psilocybin bind to.

是透過阻斷相同的血清素受體 LSD 和裸蓋菇素結合

these drugs can even relieve the hallucinations

of patients with Charles Bonnet Syndrome.

We're still a long way from understanding all the different causes

我們對理解幻覺的所有不同原因

and interconnected mechanisms of hallucinations.

和相互聯系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.

超乎想像且更緊密地與普通感知有所關聯

about how our brains construct the world we see,

關於我們的大腦是如何構成我們所看到的世界

we'll likely come to appreciate just how subjective and individual

each person's island universe of perception really is.

每個人的感知之島的宇宙是多麼的主觀和有個性

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【TED-Ed】看到神秘的東西 ... 什麼會造成幻覺？(What causes hallucinations? - Elizabeth Cox)

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