GPS正在讓我們的大腦衰退

When was the last time you navigated somewhere using a paper map? Or parked at a stop sign in a strange neighborhood, looking vaguely at the sky, trying to retrace how you got yourself into this godforsaken rabbit warren of one-way streets in the first place?

你上一次使用紙質(zhì)地圖是在什么時候?你是不是也會把車停在一個陌生街區(qū)的停車標(biāo)志旁，然后呆呆地望著天空，試圖追溯你是如何進(jìn)入這個荒涼的單行道的?

Thanks to the app on that fancy little pocket computer you carry around but call a phone, you no longer have to exercise the part of your brain to use spatial reasoning to work your way out places you're not very familiar with. In fact, a new study published in the journal Nature Communications suggests that satellite navigation, or satnav, effectively "switches off" our hippocampus and prefrontal cortex — the parts of the brain responsible for simulating routes based on prior knowledge, and planning and decision-making, respectively.

多虧了你隨身攜帶的智能手機(jī)上的GPS應(yīng)用程序，你不必再運用你的大腦進(jìn)行空間推理來幫你在不熟悉的街道找到出路。事實上，發(fā)表在《自然通訊》雜志上的一項新研究表明，衛(wèi)星導(dǎo)航能夠有效地“切斷”我們的海馬體和前額葉皮質(zhì)(大腦中負(fù)責(zé)模擬路線的部分)之間的聯(lián)系。

The research team from University College London (UCL) stuck 24 participants in fMRI machines and had them navigate through a computer simulation of streets in the city of London. The scientists monitored the subjects' brain activity while navigating from memory versus when they simply followed the directions given to them by a satnav device. It turned out that there were major spikes in the activity of both the hippocampus and the prefrontal cortex when the participants encountered giant roundabouts similar to London's Seven Dials or the Magic Roundabout of Swindon, but those parts of the brain didn't fire up when the satnav fed them instructions.

倫敦大學(xué)學(xué)院(UCL)的研究小組讓24名參與者在計算機(jī)模擬的倫敦街道中穿行，并使用功能磁共振成像儀監(jiān)測著參與者的大腦活動。結(jié)果表明，當(dāng)參與者遇到倫敦的地標(biāo)建筑時，海馬體和前額葉皮質(zhì)的活動都變得十分活躍;但是當(dāng)衛(wèi)星導(dǎo)航向他們提供指示時，大腦的這些部分并沒有活躍起來。

"If you are having a hard time navigating the mass of streets in a city, you are likely putting high demands on your hippocampus and prefrontal cortex," said lead author Dr. Hugo Spiers of UCL Experimental Psychology, in a press release. "Our results fit with models in which the hippocampus simulates journeys on future possible paths while the prefrontal cortex helps us to plan which ones will get us to our destination. When we have technology telling us which way to go, however, these parts of the brain simply don't respond to the street network. In that sense our brain has switched off its interest in the streets around us."

該研究的首席作者，UCL的實驗心理學(xué)雨果·斯皮爾斯博士在一次新聞發(fā)布會上說：“如果你在一個城市的街道網(wǎng)絡(luò)里遇到了困難，你可能會對你的海馬體和前額葉皮質(zhì)提出很高的要求。海馬體會為我們模擬出可能的路徑，而前額葉皮質(zhì)會幫助我們弄清楚哪些路徑可以帶我們到達(dá)目的地。然而，當(dāng)我們手頭有技術(shù)告訴我們該走哪條路時，大腦的這些部分根本不會對街道網(wǎng)絡(luò)做出反應(yīng)。也就是說，我們的大腦對周圍的街道已經(jīng)提不起興趣了”。

Previous research has shown that the gray matter in the memory centers of London cab drivers increases during the 3-to-4-year period of training in which they learn all London's 25,000 streets and countless landmarks, resulting in the hippocampus of these drivers being larger than normal.

之前就有研究表明，倫敦出租車駕駛員的記憶中心灰質(zhì)在3到4年的訓(xùn)練期里都有所增加。因為在這期間，他們必須記住倫敦25000條街道和無數(shù)的地標(biāo)性建筑，這使得這些駕駛員的海馬體大于正常人。

So, what's going to happen to our hippocampi and prefrontal cortices now that we don't rely on them to help us get around anymore? Will those part of our brain atrophy, shriveling to useless raisins and unable to do the work related to memory capabilities we take for granted? The answer is: We don't know yet.

如果我們真的不再依靠海馬體和前額葉皮質(zhì)來四處走動，結(jié)果會怎么樣呢?它們真的會萎縮成毫無用處的葡萄干，無法再進(jìn)行與記憶有關(guān)的工作嗎?目前的答案是：還不清楚。

"Understanding how the environment affects our brain is important," says co-author Dr. Amir-Homayoun Javadi, who ran the brain imaging analysis at UCL, and is now at the University of Kent. "My research group is now exploring how physical and cognitive activity affect brain activity in a positive way. Satnavs clearly have their uses and their limitations."

研究的合著者賈瓦迪博士表示：“了解環(huán)境如何影響我們的大腦是很重要的，我的研究小組正在探索身體和認(rèn)知活動會如何以積極的方式影響大腦活動，并弄清楚它們的用途和局限性”。