喝咖啡有助于提高記憶力

If you’re trying to commit a set of items to memory, you may want to give your brain a bit of caffeine. But how you time it matters, finds a new study out today in Nature Neuroscience. The researchers found that giving people caffeine after they memorized a series of pictures significantly boosted their ability to remember the subtler details, compared to people who’d been given dummy pills. Before you down a six-shot Americano, though, be aware that there’s a sweet spot: A 200-milligram dose of caffeine – about the amount in a large cup of coffee – was the only one to do the trick.

如果你想記住什么事情，你或許該給自己的大腦一些咖啡因。但是你在何時給它咖啡因相當重要，這是《自然神經(jīng)科學》(Nature Neuroscience)在1月13日發(fā)布的一份新研究報告中所發(fā)現(xiàn)的。研究者們發(fā)現(xiàn)，在人們記住一系列圖片之后給予他們咖啡因(相較于給予安慰劑的對比組)，能夠極大地提高記住更細微細節(jié)的能力。不過，在你狂灌六杯美式咖啡之前，請先記住最有效劑量是：200毫克的咖啡因——大概是一大杯咖啡中的咖啡因含量——才能起到這個效果。

The researchers had participants – who were not regular caffeine consumers – try to memorize a series of pictures. Afterwards, they were given a caffeine pill or a placebo (dummy) pill. Twenty-four hours later, when the caffeine was fully out of their systems, they were asked to determine which pictures in a new set had also been shown the day before. The tricky part was that some of the new items were similar but not identical to the old ones, meaning that the participants had to recall the initial items in some amount of detail.

研究者們讓不經(jīng)常攝入咖啡因的受試者嘗試記住一系列圖片。然后給予他們咖啡因藥丸或安慰劑。24小時之后，咖啡因完全排出體外，這些受試者被要求在一套新的圖片中挑出哪些圖片在前一天出現(xiàn)過。這里容易出錯的地方在于，有些圖片只是和之前的圖片相類似，但并不完全一樣，這意味著受試者必須要回憶起原來那些圖片上的某些細節(jié)。

It turned out that people in the caffeine group were much better than their non-caffeinated counterparts at recognizing the new items that were similar but not the same as old ones. And this is cool because it suggests that caffeine may influence how the brain consolidates memories.

結果證明，在辨識和舊有圖片類似卻又不盡相同的圖片方面，咖啡因組的表現(xiàn)比對照組的表現(xiàn)要好得多。這個結果很酷，因為它表明，咖啡因能影響大腦鞏固記憶的方式。

“We’ve always known that caffeine has cognitive-enhancing effects, ” said study author Michael Yassa, “but its particular effects on strengthening memories and making them resistant to forgetting has never been examined in detail in humans. We report for the first time a specific effect of caffeine on reducing forgetting over 24 hours.”

“我們一直都知道，咖啡因有提高認知力的效果，”該研究報告的作者邁克爾·亞薩(Michael Yassa)說，“但其對加強記憶力、防止遺忘的特定效果卻從未在人類身上加以詳細地驗證過。我們是首次對24小時內(nèi)咖啡因?qū)p少遺忘所產(chǎn)生的特定效果進行匯報。”

A key aspect was the caffeine was administered after the memory task, rather than before it, which ensures that other caffeine-related factors, like attention, anxiety or energy are not what’s driving the phenomenon.

重要的一點是，咖啡因是在記憶力任務之后給予的，而不是之前，這確保了其他和咖啡因相關的因素，如注意力、焦慮或能量等，并不是造成這種現(xiàn)象的原因。

Yassa added that what’s really interesting is that the study focuses on a more detailed form of memory. “If we used a standard recognition memory task without these tricky similar items, we would have found no effect of caffeine, ” he said. “However, using these items requires the brain to make a more difficult discrimination — what we call pattern separation, which seems to be the process that is enhanced by caffeine in our case.”

亞薩補充表示，真正有趣的是，這項研究專注于記憶力的一個更為細枝末節(jié)的形式。“如果我們采用一種標準辨識記憶力任務，沒有這些個容易混淆的相似點，我們可能發(fā)現(xiàn)的結果是，咖啡因沒有效果，”他說，“而采用這些相似圖片之后，就要求大腦做出更困難的辨識——這就是我們所稱之為的‘模式分辨’，在我們的研究中，咖啡因似乎就是加強了這一過程。”

Now the and his team just have to unravel why the caffeine effect occurs at all, and which brain mechanisms are responsible. “We can use brain-imaging techniques to address these questions, ” said Yassa. “We also know that caffeine is associated with healthy longevity and may have some protective effects from cognitive decline like Alzheimer’s disease. These are certainly important questions for the future.”

現(xiàn)在，亞薩和他的團隊只需闡述為什么會產(chǎn)生這種咖啡因效果，以及哪部分大腦機制對其負責的問題。“我們可以使用大腦成像技術來解決這些問題，”亞薩說，“我們還知道，咖啡因和長壽聯(lián)系在一起，也可能對老年癡呆癥等認知力衰退疾病具有防護作用。這些都是未來相當重要的問題。”

You can do an informal caffeine experiment on yourself, but again, remember that it’s the 200 mg dose – the equivalent of about two small cups or one tall Starbucks

你可以自己嘗試一下非正式的咖啡因?qū)嶒?，不過請記住，劑量是200毫克——相當于兩小杯咖啡或是一杯星巴克中杯咖啡——這一劑量的效果似乎是最大的。更大的劑量很有可能阻礙學習能力，因為會帶來各種副作用(很難知道你到底是處于不安還是焦慮狀態(tài))。這項研究無疑是激動人心的，因為它指出了適量咖啡因有助于大腦健康的另一個方面——不僅僅是長期的，更是日常的。