The capacity of visual short-term memory is set both by visual information load and by number of objects
The capacity of visual short-term memory is set both by visual information load and by number of objects
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DOI：
10.1111/j.0963-7214.2004.01502006.x
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发表时间：
2004-02-01
影响因子：
8.2
通讯作者：
Cavanagh, P
中科院分区：
文献类型：
--
作者：
Alvarez, GA;Cavanagh, P
先前的研究表明，视觉短期记忆有一个固定的容量，大约是四个物体。然而，我们发现，在我们检查的五个刺激类别中，容量变化很大，从阴影立方体的1.6到颜色的4.4（使用变化检测任务估计）。我们还估计了每个类中每个项目的信息负载，使用视觉搜索率。我们测量的不同类别的记忆容量的变化几乎完全反映在视觉搜索速度的相反方向的变化上（搜索速度和记忆容量的倒数之间的r（2）= 0.992）。刺激类别中每个项目的信息负荷越大（如较慢的搜索速度所示），人们可以在记忆中记住的类别项目就越少。外推这种线性关系表明，容量也有一个上限，大约为四个或五个对象。因此，视觉信息负荷和物体的数量都对视觉短期记忆施加了容量限制。
Previous research has suggested that visual short-term memory has a fixed capacity of about four objects. However, we found that capacity varied substantially across the five stimulus classes we examined, ranging from 1.6 for shaded cubes to 4.4 for colors (estimated using a change detection task). We also estimated the information load per item in each class, using visual search rate. The changes we measured in memory capacity across classes were almost exactly mirrored by changes in the opposite direction in visual search rate (r(2)=.992 between search rate and the reciprocal of memory capacity).Thegreater the information load of each item in a stimulus class (as indicated by a slower search rate), the fewer items from that class one can hold in memory. Extrapolating this linear relationship reveals that there is also an upper bound on capacity of approximately four or five objects. Thus, both the visual information load and number of objects impose capacity limits on visual short-term memory.