美国科学60秒 SSS 2015-03-09
时间：2019-01-20 作者：英语课 分类：2015年Scientific American(三)月
英语课
Have you ever sworn that you left your phone in the car only to find it in your pocket or on your desk or, admit it, in the fridge. Or maybe you just dreamed that you left it on the dashboard(汽车仪表盘) and the memory was so real, you had to check there first. Well, it happens to the best of us. And if you believe the latest research, it can happen to animals too.
OK, critters(小动物) don’t misplace their electronic devices, but researchers are finding that memory can be as tricky for some beasties(小动物) as it for us. Take, for example, bees. Bees flying forages(饲料) are renowned(著名的) for their ability to remember which flowers are best and where to find them. But it turns out bees can be bollixed(搞乱).
Scientists trained bumblebees(大黄蜂) bees to expect a droplet(小滴) of sugar water from 2 artificial flowers: one that was solid yellow, the other looking like an archery(剑术) target of black-and-white rings. A few minutes later, the insects were allowed to choose between those 2 flowers and a third one that had yellow rings, a combo of the previous patterns. In their short-term to us, the bees correctly showed preference for the pedals they had seen had the sweet stuff(甜食).
But when challenged a few days later, the bees got bamboozled(迷惑), they began selecting the yellow-ringed flower, even though it had never given them anything. It was like their memories had merged, or so conclude the authors in their paper in the journal Current Biology.
Meanwhile, another team of researchers found they could manipulate the memories of mice while the animals slept. As rodents(啮齿动物) skitter(飞掠而过) from here to there, what are called “place cells” in their brains record their pathways and locations. These cells than replay these movements during sleep, helping the animals remember where they have been.
In this study, researchers used the electrodes(电极) to turn on cells in the sleeping animals’ pleasure center at the same time as certain place cells lit up. This simultaneous sleepy time stimulation essentially forged an artificial memory, linking a particular location with good feelings. So when the mice woke up, they spent more time in the happy place of their dreams than anywhere else, even though nothing special actually happened there. This research is in the journal Nature Neuroscience.
Both studies suggest that we all may need to take our memories with a grain(一粒) of salt, or a dollop(团) of nectar(花蜜). Or a nice piece of cheese.
Karen Hopkin.