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.

    The research, by the French Laboratory of Neurobiology and Cognition, is published in the magazine Science.

    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.

    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.

    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.

    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.

    科學(xué)家們提出理論依據(jù)，解釋為什么當(dāng)你玩得開心的時(shí)候，時(shí)間總是過得飛快，而當(dāng)你無聊的時(shí)侯，時(shí)間卻過得特別慢。

    通過掃描發(fā)現(xiàn)，大腦活動的方式隨著我們對事情的關(guān)注程度發(fā)生變化。

    我們在無聊的時(shí)候，往往把注意力集中在時(shí)間的流逝上，這樣會使大腦活動產(chǎn)生錯(cuò)覺，總覺得時(shí)鐘似乎走得更慢。

    法國神經(jīng)生物和認(rèn)知學(xué)實(shí)驗(yàn)室進(jìn)行的此項(xiàng)研究發(fā)表在《科學(xué)》雜志上。

    在研究中，當(dāng)12名志愿者同時(shí)看一幅圖像時(shí)，研究者們用核磁共振成像掃描儀來監(jiān)控他們大腦的活動。

    志愿者們被分配了各種不同的任務(wù)。一次他們被要求專注于圖象持續(xù)的時(shí)間，另一次集中觀察圖象的色彩，第三次同時(shí)關(guān)注圖象持續(xù)的時(shí)間和色彩。

    結(jié)果表明，在觀看圖像的過程中，注意的對象多的話，就會激活大腦區(qū)域網(wǎng)絡(luò)。

    科學(xué)家們認(rèn)為如果大腦忙于關(guān)注一項(xiàng)任務(wù)中的多個(gè)方面，那么它不得不分散注意力，這樣就不太會注意到時(shí)間的流逝。

    所以，我們還沒真正注意到時(shí)間，時(shí)間就已經(jīng)過去了，而且似乎過得特別快。

    然而，如果大腦并沒有受到這樣的刺激，它就會把全部精力用來監(jiān)控時(shí)間的流逝。

    這樣就會覺得時(shí)間過得特別慢，但是事實(shí)上這可能是對現(xiàn)實(shí)情況的更準(zhǔn)確的認(rèn)識。

    事實(shí)上，研究者們發(fā)現(xiàn)，志愿者們越是注意圖像持續(xù)的時(shí)間，他們對于時(shí)間的估計(jì)就越準(zhǔn)確。

    主任研究員詹尼弗·庫爾博士說，大腦中有許多參與估計(jì)時(shí)間的區(qū)域，同時(shí)他們對行為控制和行動準(zhǔn)備也起到重要的作用。

    她說這種區(qū)域重合說明大腦在活動的間隙可能會注意到時(shí)間，在很大程度上就像音樂家用腳來記錄時(shí)間、運(yùn)動員預(yù)料發(fā)令員的槍聲一樣。