Neural measures reveal individual differences in controlling access to working memory
Neural measures reveal individual differences in controlling access to working memory
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DOI：
10.1038/nature04171
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发表时间：
2005-11-24
期刊：
影响因子：
64.8
通讯作者：
Machizawa, MG
中科院分区：
文献类型：
--
作者：
Vogel, EK;McCollough, AW;Machizawa, MG
视觉短期记忆的容量是非常有限的，只能同时保持三到四个对象（1，2）。这种极端的限制需要有效的机制来从直接环境中选择最相关的对象来表示在内存中，并限制不相关的项目消耗容量（3-5）。在这里，我们报告了一个神经生理学测量人类的记忆选择机制，衡量一个人的效率，排除不相关的项目被存储在内存中。通过检查视觉记忆的每时每刻的内容，我们观察到选择效率在个体之间存在很大差异，并且强烈预测每个人的特定记忆容量。具体地，高能力个体在仅表示相关项目方面比低能力个体有效得多，低能力个体低效地编码和维护关于显示中存在的不相关项目的信息。这些结果提供的证据表明，在许多情况下，低容量的个人实际上可能存储更多的信息在内存中比高容量的个人。事实上，这种将内存容量辅助分配给不相关对象的做法可能是造成总体存储容量差异的主要原因。
The capacity of visual short-term memory is highly limited, maintaining only three to four objects simultaneously(1,2). This extreme limitation necessitates efficient mechanisms to select only the most relevant objects from the immediate environment to be represented in memory and to restrict irrelevant items from consuming capacity(3-5). Here we report a neurophysiological measure of this memory selection mechanism in humans that gauges an individual's efficiency at excluding irrelevant items from being stored in memory. By examining the moment-by-moment contents of visual memory(6), we observe that selection efficiency varies substantially across individuals and is strongly predicted by the particular memory capacity of each person. Specifically, high capacity individuals are much more efficient at representing only the relevant items than are low capacity individuals, who inefficiently encode and maintain information about the irrelevant items present in the display. These results provide evidence that under many circumstances low capacity individuals may actually store more information in memory than high capacity individuals. Indeed, this ancillary allocation of memory capacity to irrelevant objects may be a primary source of putative differences in overall storage capacity.