科學家想開發(fā)一種“大自然處方”

A new study,published Thursday in Frontiers in Psychology,attempted to answer that question by asking participants to spend time in a place that"brings a sense of contact with nature"for at least 10 minutes per outing,three times per week,over the course of eight weeks.The researchers found that participants who immersed themselves in a"nature experience"for at least 20 minutes per outing experienced a significant decrease in their levels of the stress hormone cortisol.

心理學前沿(Frontiers in Psychology)周四發(fā)表的一項新研究試圖解決這個問題。研究人員要求研究參與者，每周三次每次至少10分鐘置身于“感知大自然環(huán)境接觸”狀態(tài)下，為期八周。研究人員發(fā)現(xiàn)，那些每次至少20分鐘沉浸在“大自然體驗”中的參與者，壓力荷爾蒙皮質(zhì)醇水平明顯下降。

The study's authors wrote that they envision ultimately developing a"nature prescription"—or"nature pill"—that health care providers can offer to their patients as a low-cost,preventive mental health treatment.(The"pill"is the time spent outside.)

論文作者說，他們最后想開發(fā)一種“大自然處方”(即“天然藥丸”)。衛(wèi)生保健機構可作為心理健康疾病低廉醫(yī)治方法推薦給患者。(“藥丸劑量”是暴躁在外部空間時間)

This research is the first step toward that goal,says MaryCarol R.Hunter,the study's lead author and an associate professor at the School for Environment and Sustainability at the University of Michigan.

該項研究主要作者、密歇根大學環(huán)境與可持續(xù)發(fā)展學院副教授MaryCarol R.Hunter說，我們的研究是邁向這一目標的第一步。

That's because the subject is tricky and expensive to study.Scientists don't yet know exactly which aspects of nature and green space—whether they're trees,grass,water,or plants—trigger the benefits of being outside.It's also difficult for them to design studies using the gold standard of a randomized clinical trial because neither scientists nor study participants are supposed to know which treatment or intervention the subject receives.In a study about exposure to nature,it's typically obvious to both the scientist and their subjects who's being sent to green spaces.

那是因為這門學科很難學，也很昂貴?？茖W家還不確切地知道自然和綠色空間的哪些方面-無論是樹木，草地，水還是植物-都會引發(fā)外出的好處。他們也很難使用隨機臨床試驗的金標準來設計研究，因為科學家和研究參與者都不應該知道受試者接受哪種治療或干預。在一項關于暴露于自然的研究中，對于被送往綠地的科學家和他們的科目來說，這通常是顯而易見的。

So Hunter and her colleagues tried an"adaptive management"approach instead.They let their 36 participants freely decide where,when,and how long they spent time in nature,provided they obeyed certain ground rules.They couldn't use phones or internet-connected devices to browse social media or the internet,and they couldn't make calls or read during their designated time outside.Their nature experience also couldn't include aerobic exercise.The researchers were collecting saliva samples that,in addition to cortisol,measured the hormone amylase,which can be influenced by physical activity.

所以，Hunter和她的同事嘗試采用了一種“適應性管理”方法。他們讓36名參與者自己決定置身于大自然位置、什么時候開始和停留時間。但應試者必須遵守某些基本規(guī)定，如不得使用手機或聯(lián)網(wǎng)設備瀏覽社交媒體或互聯(lián)網(wǎng)新聞，也不能在規(guī)定的置身于戶外時間打電話或閱讀書籍。大自然體驗時間不進行任何有氧運動。研究人員事后收集了應試者唾液樣本，除測量了皮質(zhì)醇外，還測量了人體活動影響的激素淀粉酶。

"They could pick any place they wanted,"says Hunter,"but when they went to the place they actually had to feel some resonance to nature,feel connected to it.You could go sit next to one tree and just be with the tree,that could do it for you.The same person might go to a city park free of the noise of traffic."

Hunter說：“可選擇去任何地方，但必須真正感受到與大自然產(chǎn)生共鳴，去感受大自然環(huán)境。坐在樹旁邊，和這樹在一起，對健康是有好處的。城市人也可去公園，那里沒有交通噪音。”

Peter James,an assistant professor in the department of population medicine at Harvard Medical School who has studied the link between nature and well-being,says the study's approach highlights the trade-off of letting participants shape the intervention based on their own interests.While it makes the research more feasible,it becomes difficult to know whether they stayed outdoors longer because of a personal inclination,like because they were having a great time—or some other factor unknown to the researchers.It's also then hard to know the characteristics of the participants'nature experience.

哈佛醫(yī)學院(Harvard Medical School)公共醫(yī)學系助理教授Peter James研究了自然與幸福之間的聯(lián)系(link)。他說，為研究進行順利，研究方法強調(diào)了尊重應試者興趣的重要性。但是很難知道他們根據(jù)自己意愿會在戶外待多久，若過得愉快也許更長，或存在研究人員尚不知道因素。因此很難知道參與者自然體驗感受。

"This is a consistent problem in the literature,"says James."What is a nature experience?Is it looking at trees,grass,going on a hike,walking in an urban park?It's one of the vexing problems in this area of research."

James說：“這是在文學作品中存在的一致性問題。什么是大自然體驗?是看樹、看草、是遠足、是在城市公園漫步嗎?這是該研究領域最煩人問題之一。 ”

Hunter says that people's changing perception of nature is at the heart of this challenge.Venturing into a wilderness area might feel relaxing and restorative for one person,but terrifying for someone else,who'd much rather decompress in an urban park.Doctors who want to prescribe a nature experience to their patients shouldn't focus on a standard experience but rather encourage them to go where they feel most connected to the outdoors,Hunter says.

Hunter說，人們對大自然感受不同是這問題核心。有人進入荒野地區(qū)，感到心靈得到放松，精力得到恢復。但也有人感到恐懼，他們寧愿選擇在城市公園里抒緩壓力。Hunter說，醫(yī)生若要給病人開大自然體驗藥方，就不應著眼于標準體驗模式，而應該鼓勵他們選擇適合自己戶外地方。

She also plans to release additional research based on the data collected in this study.In particular,Hunter wants to look at the self-reported information she gathered from participants about their mood,stress,and energy level to see if there's a correlation with the decrease in cortisol.

她還計劃根據(jù)研究數(shù)據(jù)公布更多內(nèi)容。Hunter尤其想看她收集的參與者撰寫的自己情緒、壓力和精力變化信息報告，了解一下這些變化是否與皮質(zhì)醇下降有關。