It was all ridges and furrows.

到處都是山脊和溝壑。

The balls were live hedgehogs, the mallets live flamingos, and the soldiers had to double themselves up and to stand on their hands and feet to make the arches.

球是活刺蝟，槌子是活火烈鳥，阿兵哥們必須把自己翻倍，手腳並用才能做出拱門。

A few might see vivid details such as the pattern of the hedgehog's quills or the flush of the Queen's face.

少數人可能會看到一些生動的細節，如刺蝟羽毛上的花紋或女王臉上的紅暈。

However, a small fraction of readers have a drastically different experience.

然而，一小部分讀者的體驗卻大相徑庭。

As the scene plays out on the page, within their heads they see absolutely nothing.

當頁面上出現這一幕時，在他們的腦海中卻什麼也看不到。

This inability to clearly visualize images in the mind's eye is known as aphantasia, and it applies to around 4% of the world's population.

這種無法在腦海中清晰呈現影像的現象被稱為 "幻視"，全世界約有 4% 的人患有這種疾病。

It was first characterized by a psychologist in the 19th century who asked study participants to visualize their breakfast table and then rate the vividness and color of this mental picture.

19 世紀的一位心理學家首次提出了這一特徵，他要求研究對象想象自己的早餐桌，然後對這一心理畫面的生動程度和色彩進行評分。

He determined that mental imagery exists on a spectrum.

他認為，心理意象存在一個光譜。

At one end are people with aphantasia, and at the other are people with hyperphantasia, with imagery so real it rivals seeing.

一端是患有幻覺症的人，另一端是患有過度幻覺症的人，他們的想象如此真實，簡直可以與視覺相媲美。

And most people land somewhere in between these two extremes.

而大多數人都處於這兩個極端之間。

But how do we know if someone with aphantasia isn't describing the same experience as someone with mental imagery, just in different terms?

但是，我們怎麼知道患有幻覺症的人和患有心理想象症的人描述的經歷是不是一樣的，只是用詞不同而已？

In other words, how does one objectively measure what's going on in someone else's mind?

換句話說，如何客觀地衡量別人心中的想法？

In one study, scientists looked for clues in people's eyes.

在一項研究中，科學家們從人們的眼睛中尋找線索。

They investigated differences in pupillary light reflexes, or how the pupil automatically constricts in response to light.

他們研究了瞳孔光反射的差異，也就是瞳孔在光照下如何自動收縮。

Even just imagining that you are looking into a light will cause the pupil to narrow.

即使只是想象自己正對著一束光，也會導致瞳孔縮小。

Or at least it will if you have mental imagery.

如果你有心理想象力，至少會這樣。

They found that the eyes of people with aphantasia don't constrict when imagining light.

他們發現，在想象光線時，患有幻視症的人的眼睛不會收縮。

Brain imaging studies may help decipher another perplexing phenomenon.

大腦成像研究可能有助於破解另一個令人困惑的現象。

People with aphantasia can see mental imagery when they dream.

患有幻覺症的人在做夢時可以看到精神意象。

How this happens is likely explained by the contrasting ways the brain generates deliberate visualization versus dream imagery.

大腦產生有意可視化和夢境意象的方式截然不同，這很可能解釋了為什麼會出現這種情況。

Typically, conjuring a mental image involves multiple brain regions, and is sometimes referred to as a top-down process.

通常情況下，心理影像的形成涉及多個大腦區域，有時也被稱為自上而下的過程。

First, actively trying to visualize an object activates cognitive control regions of our brain.

首先，積極嘗試將物體視覺化會激活我們大腦的認知控制區域。

This then drives activity in regions of the brain associated with memory and vision, creating a mental picture.

這將推動大腦中與記憶和視覺有關的區域的活動，從而形成一幅心理影像。

People with hyperphantasia tend to have stronger connections between these regions compared to those with aphantasia.

與無象限症患者相比，象限症患者這些區域之間的聯繫往往更為緊密。

As for dreaming, many scientists believe this imagery is produced by a different, bottom-up pathway, through activity deep in the brain spontaneously activating visual and memory systems.

至於做夢，許多科學家認為這種想象是通過另一種自下而上的途徑產生的，是大腦深處的活動自發激活了視覺和記憶系統。

So what causes the spectrum of mental imagery to develop?

那麼，是什麼導致了心理意象譜系的形成呢？

Aphantasia often runs in families, suggesting that the vividness of your mental canvas may be influenced by your genes.

幻覺症通常具有家族遺傳性，這表明你的思維畫面是否生動可能受基因影響。

While most people with aphantasia have it their entire lives, some people can develop it later in life, often due to brain injury or psychological conditions.

雖然大多數幻視患者終生都有幻視，但有些人可能在晚年才出現幻視，這通常是由於腦損傷或心理狀況造成的。

But in most cases, imagery extremes aren't considered disorders in need of treatment, but rather intriguing variations in human experience.

但在大多數情況下，極端意象並不被認為是需要治療的疾病，而是人類經驗中耐人尋味的變化。

For example, for those with a mind's eye, the excitement of a thrilling story will cause them to sweat a little, even if they don't notice it.

例如，對於那些有心人來說，驚心動魄的故事所帶來的興奮會讓他們微微出汗，即使他們沒有注意到。

People with aphantasia, however, lack this sweat response, presumably because it depends on the emotional effect of imagining the storyline.

然而，患有幻覺症的人卻沒有這種出汗反應，大概是因為這種反應取決於想象故事情節的情感效果。

At the same time, scientists have speculated that aphantasia may be protective against certain mental health disorders, specifically those related to negative imagery, like PTSD, though more research is needed.

同時，科學家還推測，幻覺可能對某些精神疾病，特別是與創傷後應激障礙等負面意象有關的疾病有保護作用，但這還需要更多的研究。

Recalling details, like the food served at last year's holiday party, may not be as difficult for people with hyperphantasia, as they tend to have a richer memory of past events and can relive these experiences in greater detail.

回憶細節，比如去年節日聚會上的食物，對於象素增多症患者來說可能並不困難，因為他們往往對過去的事件有更豐富的記憶，可以更詳細地重溫這些經歷。

Differences in mental imagery may even influence your career choice.

心理想象的差異甚至會影響你的職業選擇。

A survey of over 2,000 people found that those with aphantasia are more likely to work in STEM professions, while people with hyperphantasia tend to gravitate towards jobs in the arts, media, and design.

一項對 2000 多人進行的調查發現，有象患的人更有可能從事科學、技術、工程和數學方面的工作，而象患的人則傾向於從事藝術、媒體和設計方面的工作。

We may never be able to fully understand what's happening in another person's mind.

我們可能永遠無法完全理解他人的想法。

The inner worlds of those around you might be quite different from your own.

你周圍人的內心世界可能與你的截然不同。

But you can always sharpen your mind, through critical thinking and problem solving.

但你總能通過批判性思維和解決問題來磨礪自己的心智。

Brilliant is where you learn by doing, with thousands of interactive lessons in math, data analysis, programming, and AI.

Brilliant 通過數學、數據分析、編程和人工智能方面的數千節互動課程，讓您在實踐中學習。

Visit brilliant.org slash TED-Ed for 30 days free and 20% off an annual subscription.

訪問 brilliant.org slash TED-Ed，享受 30 天免費服務和 20% 的年度訂閱優惠。