Strategic trade-offs between quantity and quality in working memory.
Strategic trade-offs between quantity and quality in working memory.
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DOI：
10.1037/xhp0000211
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发表时间：
2016-08
期刊：
影响因子：
--
通讯作者：
Alvarez GA
中科院分区：
文献类型：
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作者：
Fougnie D;Cormiea SM;Kanabar A;Alvarez GA
工作内存容量是否由一个不变的限制决定--例如四个内存存储插槽？性能通常不受任务指令影响的事实被认为是对这种记忆结构模型的支持。在这里，我们修改了一个标准的工作记忆任务，以激励参与者记住更多的项目。参与者被要求在较短的记忆间隔内记住一组颜色。在一种情况下，参与者使用色轮报告随机物品的颜色。在修改后的任务中，参与者对所有项目做出反应，只有当所有反应都在色轮的正确一半上时，他们的反应才被认为是正确的。我们寻找了数量和质量之间的权衡--参与者储存了更多的物品，但在被要求报告所有物品时不那么精确。当任务被阻止时，当编码后提示任务类型时，这种权衡被观察到，但当在反应过程中提示任务类型时，没有观察到这种权衡，这表明任务差异改变了项目的主动编码和维护方式。这种对工作记忆内容的战略控制挑战了对内存存储采取僵化限制的模型。
Is working memory capacity determined by an immutable limit—e.g. four memory storage slots? The fact that performance is typically unaffected by task instructions has been taken as support for such structural models of memory. Here, we modified a standard working memory task to incentivize participants to remember more items. Participants were asked to remember a set of colors over a short retention interval. In one condition, participants reported a random item’s color using a color wheel. In the modified task, participants responded to all items and their response was only considered correct if all responses were on the correct half of the color wheel. We looked for a trade-off between quantity and quality—participants storing more items, but less precisely, when required to report them all. This trade-off was observed when tasks were blocked, when task-type was cued after encoding, but not when task-type was cued during the response, suggesting that task differences changed how items were actively encoded and maintained. This strategic control over the contents of working memory challenges models that assume inflexible limits on memory storage.