A walk in the park may soothe the mind and, in the process, change the workings of our brains in ways that improve our mental health, according to a new study of the physical effects on the brain of visiting nature.

一個新研究探索親近大自然對大腦造成的生理影響。根據研究，在公園散步可以撫慰心靈，改變我們大腦的運作方式，進而改善我們的心理健康。

Most of us today live in cities and spend far less time outside in green, natural spaces than people did several generations ago.

當今，大多數人都住在城市。與幾代之前的人相比，我們到戶外、在綠地、自然環境的時間少了很多。

City dwellers also have a higher risk for anxiety, depression and other mental illnesses than people living outside urban centers, studies show. Various studies have also found that urban dwellers with little access to green spaces have a higher incidence of psychological problems than people living near parks and that city dwellers who visit natural environments have lower levels of stress hormones immediately afterward than people who have not recently been outside. But just how a visit to a park or other green space might alter mood has been unclear. Does experiencing nature actually change our brains in some way that affects our emotional health?

多項研究顯示，住在城市的人罹患焦慮、憂鬱和其他心理疾病的風險，比住在城外的人高。各種研究提示，與住家附近有公園的人相比，幾乎沒甚麼管道接觸綠地的城市住民，心理出問題的機率更高。而且與最近沒有外出接觸大自然的人相比，造訪過自然環境的城裡人，壓力荷爾蒙濃度在造訪後立即下降。但是去一趟公園或其他綠地如何能夠改變心情，目前還不清楚。造訪大自然真的能給我們的大腦帶來影響情緒健康的變化嗎？

That possibility intrigued Gregory Bratman, a graduate student at Stanford University in California who has been studying the psychological effects of urban living. So for thestudy, which was published in Proceedings of the National Academy of Sciences, Mr. Bratman and his collaborators decided to closely scrutinize what effect a walk might have on a person’s tendency to brood.

此一可能性引起加州史丹佛大學研究生葛萊哥利．布拉特曼的興趣，他一直在研究城市生活造成的心理影響。布拉特曼與研究夥伴決定詳加檢視一次散步對一個人憂思的傾向有何可能的影響，他們並把研究結果發表在《美國國家科學院院刊》上。

Brooding, which is known among cognitive scientists as morbid rumination, is a mental state familiar to most of us, in which we can’t seem to stop chewing over the ways in which things are wrong with ourselves and our lives. It is strongly associated with increased activity in a portion of the brain known as the subgenual prefrontal cortex.

憂思在認知心理學家看來，是一種病態的反芻思考，是大多數人都熟悉的一種心理狀態：個人對自己犯的差錯和生活中遭遇的挫折無法停止鑽牛角尖。此一反芻思考與大腦胼胝體前膝下的前額葉皮層，活動增加的情況密切相關。

Mr. Bratman and his colleagues gathered 38 healthy, adult city dwellers and asked them to complete a questionnaire to determine their normal level of morbid rumination. The researchers checked for brain activity in each volunteer’s subgenual prefrontal cortex, using scans that track blood flow through the brain. Greater blood flow to parts of the brain usually signals more activity in those areas.

布拉特曼和同事招募了38名健康、成年的城市居住者，讓他們填一份問卷，用以判定他們在正常狀態下的病態反芻水準。研究人員用監測腦內血流的掃描器檢查每位志願受測者胼胝體前膝下的前額葉皮層的神經活動。流向大腦某部位的血液越多，該部位的神經活動越活躍。

Then the scientists randomly assigned half of the volunteers to walk for 90 minutes through a parklike portion of the Stanford campus or next to a loud, hectic, multi-lane highway. Immediately after completing their walks, the volunteers repeated both the questionnaire and the brain scan.

接著，科學家們隨機讓半數受測者用90分鐘在史丹佛大學校園內一個宛如公園的區域散步，另一半者則在一條嘈雜喧鬧、多線道的公路旁漫步一樣長的時間。散步結束後，這些人馬上再一次填問卷並做大腦掃描。

As might have been expected, walking along the highway had not soothed people’s minds. But the volunteers who had strolled along the quiet, tree-lined paths showed slight but meaningful improvements in their mental health, according to their scores on the questionnaire. They also had less blood flow to the subgenual prefrontal cortex. That portion of their brains was quieter.

也許你已經想到，在公路邊散步並不能撫慰受測者的心靈。然而，在清靜林蔭小徑散步的受測者，從問卷結果來看，心理健康情況出現些微但有意義的改善。他們流向膝下區前額葉皮層的血液比較少。大腦這一區域的活動也沒那麼劇烈。

These results “strongly suggest that getting out into natural environments” could be an easy and almost immediate way to improve moods for city dwellers, Mr. Bratman said.

布拉特曼說，這些結果「強烈暗示外出親近大自然」，可能是城裡人改善心情的一種簡單且幾乎立刻生效的方法。

But of course many questions remain, he said, including how much time in nature is sufficient or ideal for our mental health, as well as what aspects of the natural world are most soothing.

不過他表示，當然還有很多問題需要解答，包括從心理健康方面考慮，在大自然環境待多久才算足夠或理想呢？大自然環境的哪些方面最具安撫作用？

“There’s a tremendous amount of study that still needs to be done,” Mr. Bratman said. But in the meantime, he pointed out, there is little downside to strolling through the nearest park.

「我們還需要做極大量的研究，」布拉特曼說。但他指出，在此同時，去距離最近的公園逛逛，幾乎沒有壞處。

SEOUL, South Korea – The fate of South Korea’s kimchi industry rests on whether China considers it pickled or not.

南韓泡菜產業的命運，取決於中國是否認定它為醃製品。

When China reclassified the fermented cabbage dish several years ago, Korean exports of kimchi evaporated. As a pickled product, it did not meet China’s strict import standards. Now, China has pledged to reconsider the designation, a concession that could pave the way for a new boom in exports since the two countries sealed a broad trade deal.

幾年前，中國對發酵白菜製品進行重新歸類，南韓的泡菜出口生意化為烏有。作為醃製品，泡菜不符合中國進口產品的衛生標準。現在，中國承諾重新考慮它的歸類，在兩國簽訂廣泛的貿易協定後，這個讓步可能為南韓泡菜新一輪的出口榮景鋪好路。

The episode over kimchi, a source of deep culinary and cultural pride in South Korea and an entrée that is commonly served at every meal, reflects the sometimes complicated relationship that China has with its neighbors. As China looks to deepen its regional trade ties, such pockets of tension could flare up, creating challenges for its ambitions.

長久以來南韓飲食及文化以泡菜為榮，在南韓通常是每餐必備。中韓兩國的泡菜風波反映出中國與鄰國間，有時很複雜的關係。隨著中國尋求深化地區間的貿易關係，局部的緊張可能會激化，給中國的雄心帶來挑戰。

For years, cheaper Chinese kimchi flowed into South Korea, undercutting local producers, who were not permitted to export to China. The subject became such a sore point that kimchi was left out of important trade talks with China for years.

多年來，比較便宜的中國泡菜流向南韓，跟當地業者搶生意，南韓業者卻沒有向中國出口的許可。這件事甚至變成了一個痛處，敏感到多年來韓中重要的貿易談判都避談泡菜。

To the vendors at one food market in downtown Seoul, the prevalence of Chinese kimchi products is a reminder of China’s reach into the lives of ordinary South Koreans. “We cannot make much without importing things from China,” said Chu Kwi-soon, a 67-year-old seller of kimchi.

對首爾市中心一個食品市場的攤販來說，中國泡菜製品的大行其道讓人想起中國對尋常南韓民眾生活的影響範圍。「如果沒有從中國進口東西，我們賺不了多少錢，」67歲的泡菜商販秋貴淳表示。

China is South Korea’s biggest partner, with bilateral trade totaling $235 billion, according to the most recent figures from the Korea International Trade Association.

根據韓國國際貿易協會的最新數據，中國是南韓最大的貿易夥伴，雙邊貿易額高達2,350億美元。

China is pursuing a string of smaller pacts across Asia, using its financial heft and global influences to its advantage. In its first major move,China signed a free-trade agreementwith South Korea in June.

中國正挾其經濟實力和全球影響力，在亞洲洽簽一系列規模較小的協定。中國第一個大動作是六月與南韓簽署自由貿易協定。

Under the agreement, each country will scrap tariffs on more than 90 percent of goods, including medical equipment, electronics and kimchi, over the next 20 years. The deal is expected to increase trade between China and South Korea to $300 billion, according to estimates from the South Korean Ministry of Trade, Industry and Energy.

根據協定，中韓兩國將在未來20年內取消90%以上產品的關稅，包括醫療設備、電子產品和泡菜。南韓貿易、工業和能源部估算，這項協定可望使雙方貿易額增至三千億美元。

For South Korea’s kimchi industry, it should have been a victory. But the producers, in factories across the country, are still reeling from a bureaucratic change in China. By classifying kimchi as pickled goods, the Chinese government basically blocked all imports of the product from South Korea.

對南韓的泡菜業來說，原本也應該是一場勝利。可中國的政策變化依然讓南韓各地工廠的泡菜生產商們跌跌撞撞。藉由將泡菜歸類為醃製食品，中國政府基本上完全封殺了南韓泡菜的進口。

Kimchi is fermented and has high levels of bacteria. As such, it did not pass the hygiene standards in China normally applied to pickled goods, which are sterilized and have low amounts of bacteria.

泡菜經發酵製成，細菌含量高，因此無法通過平常適用於醃製食品的衛生標準，亦即需經殺菌消毒，細菌含量低。

In a few short years, South Korea’s once-growing kimchi trade with China plunged, from hundreds of thousands of dollars of exports a year to $16,800 last year. Instead, the cabbage dish is flowing in the opposite direction, with China now exporting hundreds of millions of dollars’ worth of kimchi a year to South Korea.

短短幾年間，南韓對中國一度成長的泡菜出口貿易重跌，從每年幾十萬美元的出口額減少到去年的16,800美元。現在反而換成逆輸入：中國每年出口價值數億美元的泡菜到南韓。

“We are feeling a sense of crisis as the owners of kimchi,” said Kim Young-rok, a South Korean politician.

南韓政界人士金泳錄說：「身為泡菜的擁有者，我們感受到危機。」

Other Chinese agricultural products have also undercut local business and dominated food markets and grocery stores, touching a nerve for farmers in South Korea, Mr. Kim said.

金泳錄說，中國其他的農產品同樣以低價和南韓店家競爭，主宰了南韓的食品市場和雜貨店，觸動南韓農民的敏感神經。

In February, the Chinese government said it would revise its regulations on kimchi in a move that was seen as alast-minute concessionto South Korea. But it is not clear whether the classification has been changed, since theWorld Trade Organizationhas not yet confirmed the new designation.

今年二月，中國政府表示將修訂針對泡菜的規定。此舉被視為中國在最後關頭對南韓作出的讓步。目前還不清楚分類標示是否已經改變，因為還沒有得到世界貿易組織的確認。

Even if the rules change, it may be difficult to reverse the damage. As cheap Chinese kimchi has flooded the market in South Korea, local producers have struggled to hold on to their business.

即使規定有所改變，南韓泡菜或許也很難扭轉損失。隨著廉價的中國泡菜湧入南韓市場，本地生產者都在苦撐。

Some have moved their factories to China to keep costs down. Others factories have closed down.

一些店家為了降低成本，已經把工廠遷到中國；有些乾脆關門大吉。

The government is trying to preserve kimchi’s cultural significance, if not its economic import.

就算保不住泡菜的經濟價值，南韓政府也要努力保存泡菜的文化重要性。

It successfully lobbied the United Nations to name kimchi to its cultural heritage list. At the World Institute of Kimchi, a research institute financed by the South Korean government, scientists havebeen told to“nurture and develop the kimchi industry that will boost the national growth.

”南韓已經成功遊說聯合國把泡菜列入聯合國非物質文化遺產名錄。在南韓政府資助的研究機構世界泡菜研究所，科學家們接到的指示是「培育發展泡菜產業，將可提振國家成長。」