英国研究人员发现,短期视觉记忆比科学家想象的更加灵活。这种记忆并不像人们原来以为的那样,只局限于有限数目的物体,而是能够在整体景象中进行“分配”。让人感兴趣的物体会分配到更多的记忆,背景因素则分配到较少的记忆。
据英国《金融时报》报道,研究人员保罗·贝斯和马苏德·侯赛因要求伦敦大学学院的志愿者观看一个电脑屏幕,屏幕上先是显示一些物体,几秒后变成空白,然后一个物体重新出现,但位置略有些变动。志愿者须说出这个物体向左还是向右移了。
随着屏幕上的物体增多,人们回忆物体原始位置的准确性出现递减。但在物体只有四、五件时,记忆的准确性并未大幅下降,这与普遍的观点不同。此项研究结果登载在8月8日的《科学》(Science)杂志上。
譬如,在观看奥运会接力赛跑时,我们可能将更多的记忆分配给我们所支持的那一队,场中关键物体——接力棒也会占据较大一部分记忆。虽然对于次要的细节,如运动员的服装和其他队的成员,记忆会比较不清晰,但在视觉上容易引起注意的细节,如运动员粉红色的头发,会吸引我们的注意。
“这涉及到将工作记忆分配给那些最重要的事物。”贝斯表示。“当某样东西吸引我们的注意时,我们将部分工作记忆转移到它上面,以备这件东西最终变得很重要。换句话说,它得到很大份额的记忆资源。”(生物谷Bioon.com)
生物谷推荐原始出处:
Science,Vol. 321. no. 5890, pp. 851 - 854,Paul M. Bays,Masud Husain
Dynamic Shifts of Limited Working Memory Resources in Human Vision
Paul M. Bays1,2* and Masud Husain1,2
Our ability to remember what we have seen is very limited. Most current views characterize this limit as a fixed number of items—only four objects—that can be held in visual working memory. We show that visual memory capacity is not fixed by the number of objects, but rather is a limited resource that is shared out dynamically between all items in the visual scene. This resource can be shifted flexibly between objects, with allocation biased by selective attention and toward targets of upcoming eye movements. The proportion of resources allocated to each item determines the precision with which it is remembered, a relation that we show is governed by a simple power law, allowing quantitative estimates of resource distribution in a scene.
1 Institute of Cognitive Neuroscience, University College London, 17 Queen Square, London WC1N 3AR, UK.
2 Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK.