太过专注使人“无意失聪”

Becoming engrossed in a good book or a crossword really can block the ability to hear, a study has found.

Scientists demonstrated that when someone focuses their full attention on something, they can become deaf to normally audible sounds. It happens because visual and hearing senses are trying to share limited brain capacity, they said.

But it can have serious consequences, and could be the cause of some road accidents. The phenomenon is known as "inattentional deafness".

Study leader Professor Nilli Lavie, from the Institute of Cognitive Neuroscience at University College London, said: " 'Inattentional deafness' is a common everyday experience. For example, when engrossed in a good book or even a captivating newspaper article, we may fail to hear the train driver's announcement and miss our stop. Or if we're texting while walking, we may fail to hear a car approaching and attempt to cross the road without looking."

In the study, 100 volunteers performed computer tasks involving a series of croSome were easy, such as being able to tell that the arms of the cross were different colors. Others were more challenging and involved identifying subtle length differences.

At certain points, a tone was played unexpectedly through the headphones, after which the experiment was stopped.

Participants were then asked if they had heard the sound.

When judging colors, only two in ten volunteers missed the tone. But when focusing on the more difficult tasks, eight in ten failed to hear it.

Prof Lavie wrote in the journal Attention, Perception And Psychophysics: "Hearing is often thought to have evolved as an early warning system that does not depend on attention, yet our work shows that if our attention is taken elsewhere, we can be effectively deaf to the world around us."

It is well known that many road accidents are caused by drivers' inattention.

Sounds such as a lorry beeping while reversing, a cyclist's bell or a scooter horn could all be missed by a motorist focusing intently on visual information from a road sign or satellite -navigation map.

一项研究发现，当人们全神贯注看书或做填字游戏时，他们会暂时听不到周围的声音。

科学家解释说，当人们集中精神做事时，会对外界一般的声音充耳不闻。之所以会这样，是因为大脑中的视觉细胞和听觉细胞会争夺有限的大脑空间。

这在某些时候会产生极其严重的后果，比如引发交通事故。这种现象被称作是“无意失聪”。

伦敦大学学院认知神经学研究所的尼尔利•拉唯教授是这项研究的带头人，他说：“‘无意失聪’这种现象在日常生活中很常见。比如，当你全神贯注地盯着一本书或报纸上的一篇文章时，你很有可能会因为没听见火车报站的声音而坐过站。或者你一边走路一边发短信，汽车开来了也听不见，还要横穿马路。”

研究中，100位志愿者要在电脑上完成一些试验项目，包括一些简单的小游戏，例如辨别填字游戏的行列颜色是否相同。有的则属于比较高难，需要甄别出细微的长度差别。

在志愿者答题的过程中，研究人员会突然播放一个声音，答题过程也会随之终止。

然后研究人员会询问志愿者是否听见了这个声音。

在做色彩辨别时，仅有两成人没听见这个声音。而在回答更为困难的问题时，有八成人都没听见这个声音。

拉唯教授在给《注意力、感知力和心理物理学》杂志撰写的文章中称：“人们一般认为，在人类进化的初级阶段，听觉作为一种预警能力并不需要注意力。然而我们的研究发现，如果人的注意力被某种东西吸引，他就听不见周围世界的声音。”

众所周知，许多交通事故都是由于驾驶员注意力不集中造成的。

比如当摩托车驾驶员仔细看路边的指示牌或电子导航地图时，他就有可能听不到卡车、自行车、踏板车朝他开过来的声音。