Scientists have come up with a theory for why time flies when you are having fun-- and drags when you are bored.

    Scans have shown that patterns of activity in the brain change depending on how we focus on a task.
    Concentrating on time passing, as we do when bored, will trigger brain activity which will make it seem as though the clock is ticking more slowly.
    我們在無聊的時候，往往把注意力集中在時間的流逝上，這樣會使大腦活動產生錯覺，總覺得時鐘似乎走得更慢

    The research, by the French Laboratory of Neurobiology and Cognition, is published in the magazine Science.
    法國神經生物和認知學實驗室進行的此項研究發表在《科學》雜誌上。
    In the study, 12 volunteers watched an image while researchers monitored their brain activity using MRI scans.

    Volunteers were given a variety of tasks. In one they were told to concentrate simply on the duration of an image, in another they were asked to focus on the colour, and in a third they were asked to concentrate on both duration and colour.
    The results showed that a network of brain regions was activated when more subjects were paid attention to duration.
    結果表明，在觀看圖像的過程中，注意的物件多的話，就會啟動大腦區域網路。

    It is thought that if the brain is busy focusing on many aspects of a task, then it has to spread its resources thinly, and pays less heed to time passing. Therefore, time passes without us really noticing it, and seems to go quickly.
    However, if the brain is not stimulated in this way, it concentrates its full energies on monitoring the passing of time. This may make time seem to drag, but in fact it is probably a more accurate perception of reality.

    Indeed, the researchers found that the more volunteers concentrated on the duration of the images, the more accurate were their estimates of its duration.
    事實上，研究者們發現，志願者們越是注意圖像持續的時間，他們對於時間的估計就越準確。
    Lead researcher Dr Jennifer Coull said many of the areas of the brain involved in estimating time were the same that played a key role in controlling movement, and preparing for action.
    主任研究員 Coull 博士說，大腦中有許多參與估計時間的區域，同時他們對行為控制和行動準備也起到重要的作用。

    She said this overlap suggests that the brain may make sense of time as intervals between movements, in much the same way as a musician marks time with his foot, or an athlete anticipates the sound of a starter's pistol.

    Professor Tonmoy Sharma, director of the Clinical Neuroscience Research Centre, told BBC News Online the research was "interesting neuroscience".
    "It is interesting that the same parts of the brain that are involved in motor function are also involved time perception."
    Professor Sharma said there was growing evidence that specific functions were not controlled exclusively by individual areas of the brain, but by complex networks within the organ.