Being Older but Wiser Is Supported by the Data
證據顯示老來未必糊塗
By Benedict Carey

Behind all those comments for older adults that show appreciation for their wisdom is something that scientists have had a hard time characterizing: mental faculties that improve with age.
在對年長者的智慧表示讚賞的各種評語背後，隱藏著科學家一直難以描繪的東西：隨年齡而增強的人類心智能力。

Knowledge is a large part of the equation. People who are middle-aged and older tend to know more than young adults, by virtue of having been around longer, and score higher on vocabulary tests, crossword puzzles and other measures of so-called crystallized intelligence.
知識占了一大部分。中年或更年長的人，占了見多識廣之便，知道的通常比年輕人多，在字彙測驗、填字謎和其他晶體智力的測量，成績也比較高。

Still, young adults who consult their elders don’t do so just to gather facts or solve crosswords. Nor are they looking for help with short-term memory or puzzle solving. Those abilities, called fluid intelligence, peak in the 20s.
不過，年輕人徵詢長輩意見不光是為了搜集事實或玩填字遊戲。也不是尋求短期記憶的協助或解謎。這些能力稱為流質智力，在二十歲左右達到高峰。

No, the older brain offers something more, according to a new paper in the journal Psychological Science. Elements of social judgment and short-term memory, important pieces of the cognitive puzzle, may peak later in life than previously thought.
根據《心理科學》期刊的新論文，年長者的大腦提供更多的東西。社會判斷的要素和短期記憶，認知拼圖的重要部分，在人一生中到達顛峰的時間可能比之前認為的晚。

The postdoctoral fellows Joshua Hartshorne of the Massachusetts Institute of Technology and Laura Germineof Harvard and Massachusetts General Hospital analyzed scores on cognitive tests taken by people of all ages. The researchers found that the broad split in age-related cognition – fluid in the young, crystallized in the old – masked several important nuances.
兩位博士後研究員－麻省理工學院的約書亞．哈特修恩和哈佛大學及麻州綄合醫院和蘿拉．傑曼－分析各年齡層參加認知測驗的成績，在與年齡相關的認知上發現，「年輕人流質智力強，年長者晶體智力強」的籠統二分法掩蓋了一些重要的細微差異。

“There are a lot more patterns going on, and we need to take those into account to fully understand the effects of age on cognition,” Dr. Hartshorne said.
哈特修恩說：「實際存在的模式遠多於此，我們必須將其列入考慮，才能完整理解年齡對認知的影響。」

A year ago, German scientists argued that cognitive “deficits” in aging were caused largely by the accumulation of knowledge – the brain slows down because it has to search a larger mental library of facts. Scientists have debated that idea.
一年前，德國科學家主張因年齡增長而產生的認知「赤字」大部分起因於知識的累積－大腦變慢是因為必須在更大的心理資料庫裡搜尋。科學家對此說法有所爭辯。

Experts said the new analysis raises the question: Are there distinct, independent elements of memory and cognition that peak at varying times of life?
專家表示，新分析產生的問題是：記憶和認知中有無獨特且獨立的要素在人生的不同年齡階段達到顛峰？

The study evaluated historic scores from the Wechsler intelligence test, and compared them with more recent results from tens of thousands of people who took short cognitive tests on the authors’ websites, testmybrain.org. The one drawback of this approach is that, because it didn’t follow the same people over a lifetime, it might have missed the effect of different cultural experiences, said K. Warner Schaie, a researcher at Pennsylvania State University.
研究求出魏氏智力測驗古早成績的數值，拿來和數萬人最近在研究作者網站testmybrain.org和gameswithwords.org參加認知小測驗的成績相比。賓州州立大學研究者K．華納．夏伊說，這種方式的一個缺點是因為沒有追蹤同一個人 一輩子，可能會漏掉不同文化經驗的影響。

Participants on the websites were 10 to 89 years old, and they took a battery of tests, measuring skills like memory for abstract symbols and strings of digits, problem solving, and facility reading emotions from strangers’ eyes.
到網站參加測驗者從10歲到89歲，而且參加一系列測驗，評量的技能包括對抽象符號和一連串數字的記憶，解決問題和從陌生人的眼神判讀情緒的能力。

At least as important, the researchers looked at the effect of age on each type of test. The result of the new approach? “We found different abilities really maturing or ripening at different ages,” Dr. Germine said. “It’s a much richer picture of the life span than just calling it aging.”
起碼同樣重要的是，研究人員檢視年齡在各項測驗中的影響。新方式的結果如何呢？「我們發現不同的能力的確在不同的年齡成熟或圓熟。」傑曼說：「這遠比單單用老化來形容更能觀照人的一生。」

Processing speed – the quickness with which someone can manipulate digits, words or images – generally peaks in the late teens, Dr. Germine and Dr. Hartshorne confirmed, and memory for some things, like names, does so in the early 20s. But working memory peaks at least a decade later and is slow to decline. The ability to recall faces and do some mental manipulation of numbers peaked about age 30, the study found.
運算速度，意指某人處理數字、單字和圖像能有多快，傑曼和哈特修恩證實，通常在青少年末期達到巔峰，對姓名等事物的記憶在20歲出頭最強。但是工作記憶至少要等到十年後才會到達顛峰，衰退的速度也慢。研究發現，回想起臉孔和某些數字的心智操作能力大約在30歲最強。

The researchers also analyzed results from the Reading the Mind in the Eyes test. The picture that emerges from these findings is of an older brain that moves more slowly than its younger self, but is just as accurate in many areas and more adept at reading others’ moods - on top of being more knowledgeable. That’s a handy combination, given that so many important decisions people make intimately affects others.
研究人員也分析了從眼讀心測試的結果。從這些發現中出現的圖像是，一個較老的大腦動得比年輕的大腦慢，但是在許多領域一樣準確，在判斷他人心思方面則更熟練，而且知識更淵博。這是很有用的密碼，因為許多人們暗中作的決定對他人造成影響。

The details of this picture of the aging brain are still far from clear, and social measures like the Reading the Mind in the Eyes test have not been used much in this kind of research, Dr. Hambrick and other experts said. And it is not apparent from the new analysis whether changes in cognition with age result from a single cause – like a decline in the speed of neural transmission – or to multiple ones.
韓布力克博士（編者按：Zach Hambrick，密西根州大心理學教授）與其他專家表示，老化中的大腦運作的細節，還有許多地方搞不清楚，類似從眼讀心的社會評量在這類研究運用的也不多。從新分析中也看不出認知隨年齡改變是基於單一原因－像是神經傳導速度減緩－或是有多種原因。

原文參照：
http://www.nytimes.com/2015/03/17/health/older-really-can-mean-wiser.html

紐約時報中文版翻譯：
http://cn.nytimes.com/health/20150323/c23cognition/zh-hant/

2015-03-31聯合報/G5版/UNITED DAILY NEWS 張佑生譯 原文參見紐時週報十版下