Peters Benjamin, Rahm Benjamin, Kaiser Jochen, Bledowski Christoph
Institute of Medical Psychology, Goethe University, Frankfurt am Main, Germany.
Zuckerman Institute, Columbia University, New York, USA.
J Vis. 2019 Jul 1;19(7):3. doi: 10.1167/19.7.3.
Working memory enables the storage of few items for a short period of time. Previous research has shown that items in working memory cannot be accessed equally well, indicating that they are held in at least two different states with different capacity limitations. However, it is unclear whether differences between states are due to limitations of the number of items that can be stored, or the quality with which items are stored. We employed a sequential whole-report procedure where participants reported the remembered orientation of each of two or four encoded Gabor patches. In addition, they rated their memory confidence prior to each report. Participants performed 600 trials per condition, allowing us to obtain reliable subjective ratings and estimates of precision, guessing, and misreport using a mixture model, separately for each sequential report. Different measures of memory quality consistently showed discontinuous trajectories across reports with a steep drop from the first to the second remembered item but only slight decreases thereafter. In contrast, both reported and modeled guessing changed continuously across reports. Our results support the notion of two states in working memory and show that they are distinguished by memory quality rather than quantity.
工作记忆能够在短时间内存储少量项目。先前的研究表明,工作记忆中的项目不能被同等程度地访问,这表明它们至少以两种具有不同容量限制的不同状态被保持。然而,尚不清楚状态之间的差异是由于可存储项目数量的限制,还是项目存储的质量。我们采用了一种顺序全报告程序,参与者报告两个或四个编码的加博尔斑块中每个斑块的记忆方向。此外,他们在每次报告之前对自己的记忆信心进行评分。参与者在每个条件下进行600次试验,这使我们能够使用混合模型分别为每个顺序报告获得可靠的主观评分以及对准确性、猜测和错误报告的估计。不同的记忆质量测量方法始终显示出跨报告的不连续轨迹,从第一个记忆项目到第二个记忆项目有急剧下降,但此后仅略有下降。相比之下,报告的和建模的猜测在各报告之间持续变化。我们的结果支持工作记忆中存在两种状态的观点,并表明它们是由记忆质量而非数量来区分的。