Awh Edward, Barton Brian, Vogel Edward K
University of Oregon, Eugene, OR 97403-1227, USA.
Psychol Sci. 2007 Jul;18(7):622-8. doi: 10.1111/j.1467-9280.2007.01949.x.
Does visual working memory represent a fixed number of objects, or is capacity reduced as object complexity increases? We measured accuracy in detecting changes between sample and test displays and found that capacity estimates dropped as complexity increased. However, these apparent capacity reductions were strongly correlated with increases in sample-test similarity (r= .97), raising the possibility that change detection was limited by errors in comparing the sample and test, rather than by the number of items that were maintained in working memory. Accordingly, when sample-test similarity was low, capacity estimates for even the most complex objects were equivalent to the estimate for the simplest objects (r= .88), suggesting that visual working memory represents a fixed number of items regardless of complexity. Finally, a correlational analysis suggested a two-factor model of working memory ability, in which the number and resolution of representations in working memory correspond to distinct dimensions of memory ability.
视觉工作记忆是表征固定数量的物体，还是随着物体复杂性的增加而容量减小？我们测量了检测样本显示和测试显示之间变化的准确性，发现随着复杂性的增加，容量估计值下降。然而，这些明显的容量减少与样本-测试相似性的增加密切相关（r = 0.97），这增加了一种可能性，即变化检测受样本与测试比较中的误差限制，而非受工作记忆中保持的项目数量限制。因此，当样本-测试相似性较低时，即使是最复杂物体的容量估计也与最简单物体的估计相当（r = 0.88），这表明无论复杂性如何，视觉工作记忆都表征固定数量的项目。最后，一项相关分析提出了工作记忆能力的双因素模型，其中工作记忆中表征的数量和分辨率对应于记忆能力的不同维度。
