With it, we can communicate our thoughts and feelings

我們藉由語言傳達想法和感覺

lose ourselves in novels

享受閱讀的樂趣

send text messages

傳訊息

and greet friends

跟朋友問好

It's hard to imagine being unable to turn thoughts into words

很難想像有無法把想法轉為言語的時候

But if the delicate web of language networks in your brain

但如果大腦中複雜的語言網絡

became disrupted by stroke, illness, or trauma

因為中風、疾病或創傷而受阻

you could find yourself truly at a loss for words

你就可能會有「有口難言」的情況

This disorder, called aphasia, can impair all aspects of communication

這種病症叫做「失語症」，造成溝通上的困難

People who have aphasia remain as intelligent as ever

失語症病患智力不變

They know what they want to say

他們知道自己想說什麼

but can't always get their words to come out correctly

卻總是無法準確地傳達自己的訊息

They may unintentionally use substitutions called paraphasias

他們可能沒發現自己無意間使用錯誤的字詞彙，這種病症稱為「誤語症」(paraphasias)

switching related words, like saying "dog" for "cat",

他們會把甲、乙兩相關字詞說反，像是把狗說成貓

or words that sound similar, such as "house" for "horse."

或說出另一個發音相近的字詞，例如把「房子」(house)說成「馬」(horse)

Sometimes, their words may even be unrecognizable

有時候別人會聽不懂他們在說什麼

There are several types of aphasia grouped into two categories:

失語症分為以下兩類：

fluent, or receptive, aphasia

理解性失語症

and non-fluent, or expressive, aphasia

表達性失語症

People with fluent aphasia may have normal vocal inflection

理解性失語症病患說話音調正常

but use words that lack meaning

但卻用沒有意義的字詞來表達

They have difficulty comprehending the speech of others

他們不太能理解他人所說的話

and are frequently unable to recognize their own speech errors

也常常無法意識到自己說話所犯的錯誤

People with non-fluent aphasia, on the other hand

另一方面，表達性失語症的病患

may have good comprehension

能夠理解他人所說的話

but will experience long hesitations between words and make grammatical errors

但在說話時要花好一些時間去想，也會犯文法錯誤

We all have that tip-of-the-tongue feeling from time to time

我們偶爾都會有要說什麼卻一時想不起來的時候

when we can't think of a word

當下會突然想不起某個字彙

but having aphasia can make it hard to name simple, everyday objects

但罹患失語症的人甚至無法說出簡單的日常物品

Even reading and writing can be difficult and frustrating

閱讀和寫作就更不用說了，困難又令人沮喪

So how does this language loss happen?

為什麼這種「有口難言」的情形會發生呢？

The human brain has two hemispheres

人腦分為左右兩半

In most people, the left hemisphere governs language

大部分人的左腦掌管語言

We know this because in 1861

1861年

the physician Paul Broca studied a patient

內科醫生保羅布羅卡 (Paul Broca) 研究一名病患

who lost the ability to use all but a single word, "tan."

那位病患就只說的出「tan」這個字，其他都說不出來

During a postmortem study of that patient's brain

這名病患死後布羅卡醫生解剖他的大腦

Broca discovered a large lesion in the left hemisphere

發現他的左半腦有個大傷口

now known as Broca's area

這個區塊後來就稱作「布羅卡區」(Broca's area)

Scientists today believe that Broca's area is responsible in part for naming objects

現在科學家相信人能說出物品名稱的能力部分來自布羅卡區

and coordinating the muscles involved in speech

布羅卡區也負責協調說話時所用到的肌肉

Behind Broca's area is Wernicke's area near the auditory cortex.

此區塊後面是韋尼克區 (Wernicke's area)，靠近聽覺皮質區

That's where the brain attaches meaning to speech sounds

韋尼克區的功能是讓人理解字詞的意思

Damage to Wernicke's area impairs the brain's ability to comprehend language

這個區塊如果受傷便會影響語言的理解

Aphasia is caused by injury to one or both of these specialized language areas

其中一個區塊或兩個區塊都受傷就會造成失語症

Fortunately, there are other areas of the brain

幸運的是，大腦還有其他區塊

which support these language centers

輔助這些語言中樞

and can assist with communication

也能協助溝通

Even brain areas that control movement are connected to language

雖然控制動作的大腦區塊和語言中樞有連結

FMRI studies found that when we hear action words, like "run" or "dance"

核磁共振造影研究指出當我們聽到動詞，像是「跑」或「跳舞」

parts of the brain responsible for movement light up

大腦負責動作的區塊會變得活躍

as if the body was actually running or dancing

就如身體真的動起來，開始跑步或跳舞一樣

Our other hemisphere contributes to language, too

右半腦也和語言相關

enhancing the rhythm and intonation of our speech

讓我們的話語有節奏和音調

These non-language areas sometimes assist people with aphasia

這些非語言區塊有時候能幫助失語症病患

when communication is difficult.

對他們他來溝通不是件易事

So how common is aphasia?

罹患失語症的人有多少呢？

Approximately 1 million people in the U.S. alone have it

光在美國就大約有一百萬個失語症病患

with an estimated 80,000 new cases per year.

每年預計增加八萬個

About one-third of stroke survivors suffer from aphasia

大約三分之一中風過的人是失語症病患

making it more prevalent than Parkinson's disease

人數比罹患帕金森氏症的病患還多

or multiple sclerosis

也比多發性硬化症的病患還多

yet less widely known

儘管如此，知道失語症的人並不多

There is one rare form of aphasia called primary progressive aphasia, or PPA,

還有另一個少見的失語症叫做漸發性失語症 (primary progressive aphasia, PPA)

which is not caused by stroke or brain injury

漸發性失語症並非由中風或大腦受傷引起

but is actually a form of dementia

這其實是一種失智症

in which language loss is the first symptom

第一個症狀是喪失語言能力

The goal in treating PPA is to maintain language function for as long as possible

治療漸發性失語症的目標是盡量維持語言能力，愈久愈好

before other symptoms of dementia eventually occur

在其他失智症狀出現之前維持語言能力

However, when aphasia is acquired from a stroke or brain trauma

但是當失語症是因中風或大腦創傷引起

language improvement may be achieved through speech therapy

病患能透過語言治療讓情況好轉

Our brain's ability to repair itself, known as brain plasticity

大腦自我修復的能力，也稱作大腦可塑性

permits areas surrounding a brain lesion

讓大腦受傷部位的周圍區塊

to take over some functions during the recovery process

能夠在復原過程中替代其他功能

Scientists have been conducting experiments using new forms of technology

科學家已經用新的科技做過實驗

which they believe may encourage brain plasticity in people with aphasia

他們相信這種新科技能增加失語症病患的大腦可塑性

Meanwhile, many people with aphasia remain isolated

同時，許多失語症病患離群索居

afraid that others won't understand them or give them extra time to speak

深怕其他人聽不懂他們說什麼或不願多花時間聽他們說話

By offering them the time and flexibility to communicate in whatever way they can

給予時間和彈性讓他們能夠自在地說話

you can help open the door to language again,

就能幫助他們再度回到語言的懷抱

moving beyond the limitations of aphasia

不再受失語症的種種限制