The left brain vs. right brain myth - Elizabeth Waters

Translator: Vanessa Leung Reviewer: Sylvia He

Behold the human brain,

我地睇到人類嘅腦

it's lumpy landscape visibly split into a left and right side.

係分成左右兩塊嘅

This structure has inspired one of the most pervasive ideas about the brain,

呢個結構令人都產生 一個非常普遍嘅觀點

that the left side controls logic

左腦控制人嘅邏輯思維

and the right, creativity.

右腦就控制人嘅創意

And yet, this is a myth unsupported by scientific evidence.

但其實呢個理論並無科學嘅依據

So how did this misleading idea come about,

咁點解會有呢個錯誤理論產生

and what does it get wrong?

佢又錯係邊度呢？

It's true that the brain has a right and a left side.

人腦的確分成左右兩部分

This is most apparent with the outer layer, or the cortex.

從外層同皮質就可以睇到

Internal regions, like the striatum,

內部結構 例如紋狀體

hypothalamus,

下丘腦

thalamus,

丘腦

and brain stem

同腦幹

appear to be made from continuous tissue,

睇上去好似由連續組織構成

but in fact, they're also organized with left and right sides.

但事實上 佢哋同時都受左右腦組織

The left and the right sides of the brain do control different body functions,

左右腦都控制唔同嘅身體功能

such as movement and sight.

例如運動同視力

The brain's right side controls the motion of the left arm and leg and vice versa.

右腦控制左手左腳嘅運動 反過來都係咁

The visual system is even more complex.

視覺系統就更加複雜

Each eye has a left and right visual field.

每隻眼都分成左右兩個視野

Both left visual fields are sent to the right side of the brain,

兩隻眼嘅左視野都係右腦負責

and both right fields are sent to the left side.

兩隻眼嘅右視野就係左腦負責

So the brain uses both sides to make a complete image of the world.

左右腦一齊運作先可以 睇到完整嘅畫面

Scientists don't know for sure why we have that crossing over.

科學家都唔知點解 人嘅左右腦會有交換分工

One theory is it began soon after animals developed more complex nervous systems

其中一個理論係 交換分工令動物可以有更快嘅反應

because it gave the survival advantage of quicker reflexes.

所以喺動物發展神經系統之後無幾耐 就有呢個現象了

If an animal sees a predator coming from its left side,

如果一個動物睇到捕食者從左邊過來

it's best off escaping to the right.

佢最好從右邊逃走

So we can say that vision and movement control are two systems

所以視覺同運動其實係由 左右腦兩個系統控制嘅

that rely on this left-right structure,

但就唔可以過度理解成

but problems arise when we over-extend that idea to logic and creativity.

左右腦分別負責邏輯同創意

This misconception began in the mid-1800s

呢個誤解來源於 18 世紀中

when two neurologists, Broca and Wernicke,

當 Broca 同 Wernicke 兩個神經學家研究

examined patients who had problems communicating due to injuries.

因創傷有溝通問題嘅病人嘅時候

The researchers found damage to the patients' left temporal lobes,

佢哋發現病人嘅左顳葉有創傷

so they suggested that language is controlled by the left side of the brain.

所以推測語言能力係左腦控制嘅

That captured the popular imagination.

呢個推論好快傳播開來

Author Robert Louis Stevenson

作家 Robert Louis Stevenson

then introduced the idea of a logical left hemisphere

曾經通過佢筆下嘅角色 Jekyll 博士和 Hyde 先生

competing with an emotional right hemisphere

引出理性嘅左腦

represented by his characters Dr. Jekyll and Mr. Hyde.

同感性嘅右腦對抗嘅諗法

But this idea didn't hold up when doctors and scientists

但當醫生同科學家研究

examined patients who were missing a hemisphere

缺少一個大腦半球

or had their two hemispheres separated.

或者兩個大腦半球分割嘅病人

These patients showed a complete range of behaviors,

嘅時候發現 呢個理論係錯誤的

both logical and creative.

呢啲病人表現出一系列嘅行為

Later research showed that one side of the brain is more active than the other

既有邏輯性嘅亦有創意性嘅

for some functions.

之後研究發現 當大腦運行某些功能時

Language is more localized to the left

其一側會比另外一側更活躍 語言功能更加依賴左腦

and attention to the right.

而注意力更加依賴右腦

So one side of the brain may do more work,

所以一側嘅大腦可能會負責更多嘅工作

but this varies by system rather than by person.

但呢個就取決於唔同系統嘅運作 而唔係個人

There isn't any evidence to suggest

無任何證據證明

that individuals have dominant sides of the brain,

一個人會由一邊腦來主導

or to support the idea of a left-right split

左右腦分別控制 邏輯和創意力

between logic and creativity.

有啲人會特別有邏輯或者有創意

Some people may be particularly logical or creative,

但同佢哋嘅左右腦並無關係

but that has nothing to do with the sides of their brains.

甚至「邏輯同創意相互矛盾」嘅觀點

And even the idea of logic and creativity being at odds with each other

都係錯嘅

doesn't hold up well.

解決複雜嘅數學問題需要有創意

Solving complex math problems requires inspired creativity

而好多充滿活力嘅藝術作品

and many vibrant works of art have intricate logical frameworks.

都有復雜嘅邏輯框架

Almost every feat of creativity and logic

幾乎每一個創造力同邏輯嘅壯舉

carries the mark of the whole brain functioning as one.

都係依靠左右腦一齊運作嘅功勞