你是否在與人交談時，很難看著對方的眼睛把話說下去？人們通常認為，講話時避免眼神接觸是怕尷尬或不自信的表現。然而，日本京都大學的科學家們給出了另一種科學解釋。
It turns out we're not just awkward, our brains actually can't handle the tasks of thinking of the right words and focusing on a face at the same time.
事實上，我們並不只是尷尬，而是大腦無法同時兼顧「思考恰當詞彙」和「眼神接觸」的任務。
The effect becomes more noticeable when someone is trying to come up with less familiar words, which is thought to use the same mental resources as sustaining eye contact.
當人們努力搜索不太熟悉的詞彙時，這個效應會更加明顯。科學家認為，這兩項任務佔用同樣的心理資源。
Scientists from Kyoto University in Japan put this to the test in 2016 by having 26 volunteers play word association games while staring at computer-generated faces.
2016年，日本京都大學的科學家們為此進行了一項實驗。他們讓26名志願者在玩詞彙聯想遊戲的同時，盯著由計算機生成的臉龐。
When making eye contact, the participants found it harder to come up with links between words.
在進行眼神接觸時，受試者更難想出詞彙之間的關聯。
"Although eye contact and verbal processing appear independent, people frequently avert their eyes from interlocutors during conversation," wrote the researchers.
研究人員寫道：「儘管眼神交流和語言處理似乎是獨立的，但人們經常在談話中避開對話者的眼睛。」
"This suggests that there is interference between these processes."
「這表明，這兩個過程之間存在幹擾。」
The volunteers were tested while looking at both animations of faces making eye contact and animations of faces looking away. They were also asked to think of links between easily associated words and words where there are a lot of competing associations.
志願者在測試中盯著的圖畫臉龐既有直視鏡頭的，也有看向其他方向的。他們進行聯想的詞彙也有容易聯想的詞，和存在大量競爭聯想詞。
For example, thinking of a verb for 'knife' is relatively easy, because you can't do much more than cut or stab with one. Coming up with an associated verb for 'folder' is harder, considering you could open, close, or fill them.
舉例而言：聯想和「刀（knife）」有關的動詞比較簡單，我們通常只能用刀來「切（cut）」或者「刺（stab）」。聯想和「文件夾（folder）」有關的動詞更加困難，因為你可以打開（open）」、「合上（close）」或者「填充（fill）」文件夾。
The volunteers took longer to think of words when they were making eye contact, but only when difficult word associations were involved. The researchers suspect the hesitation indicates the brain is handling too much information at once.
志願者在進行眼神接觸時，需要花更長時間才能想出答案——但這種效應只發生在困難任務中。研究人員推測：這種遲疑意味著，大腦同時處理太多信息了。
So while making eye contact and holding a conversation is certainly possible, this is evidence that they can both draw on the same pool of cognitive resources, and sometimes that pool starts to run a little dry.
雖然人們的確能在交流時保持眼神接觸，但這個證據表明，這兩個過程能從相同的認知資源池中提取信息，以至於有時候這個池子開始有些見底了。
The sample size used was pretty small, but it's an interesting hypothesis.
實驗採用的樣本非常少，但這是一個很有意思的假設。
In 2015, Italian psychologist Giovanni Caputo demonstrated that staring into someone else's eyes for just 10 minutes induced an altered state of consciousness. Participants saw hallucinations of monsters, their relatives, and even their own faces.
2015年，義大利心理學家喬瓦尼•卡普託證明，只要盯著某人眼睛10分鐘，就會誘發意識改變狀態。受試者會看到各種幻想，如怪物、親人、甚至自己的臉龐。
It seems that a process called neural adaptation is the cause, where our brains gradually alter their response to a stimulus that doesn't change – so when you put your hand on a table, you immediately feel it, but that feeling lessens as you keep your hand there.
這似乎與一個被稱為「神經適應」的過程有關，即如果刺激保持不變，大腦會逐漸改變對它的反應——因此，當你把手放在桌上時，會立刻有所感覺；但如果手一直放在桌上，感覺就會逐漸減弱。
The volunteers making eye contact and associating words may also be experiencing some kind of neural adaptation, but for now the Kyoto University researchers are calling for further study into the links between verbal and non-verbal communication.
在京都大學的實驗中，志願者同時進行眼神接觸和聯想詞彙時，可能也經歷了某種神經適應。京都大學的研究人員目前正在呼籲進一步研究語言交流和非語言交流之間的聯繫。
And in the meantime, if someone looks away while they're talking to you, they might not be being rude – they could just have an overloaded cognitive system.
同時，如果有人在談話過程中看向別處，他們可能不是不禮貌，只是認知系統超載了。
英文來源：sciencealert.com
編譯：董靜
審校：yaning