Department of Psychological and Brain Sciences, University of California, Santa Barbara, Santa Barbara, CA, USA.
Atten Percept Psychophys. 2023 Jul;85(5):1710-1721. doi: 10.3758/s13414-022-02646-5. Epub 2023 Jan 31.
Working memory (WM) is the ability to maintain and manipulate information no longer accessible in the environment. The brain maintains WM representations over delay periods in noisy population-level activation patterns, resulting in variability in WM representations across items and trials. It is established that participants can introspect aspects of the quality of WM representations, and that they can accurately compare which of several WM representations of stimulus features like orientation or color is better on each trial. However, whether this ability to evaluate and compare the quality of multiple WM representations extends to spatial WM tasks remains unknown. Here, we employed a memory-guided saccade task to test recall errors for remembered spatial locations when participants were allowed to choose the most precise representation to report. Participants remembered either one or two spatial locations over a delay and reported one item's location with a saccade. On trials with two spatial locations, participants reported either the spatial location of a randomly cued item, or the location of the stimulus they remembered best. We found a significant improvement in recall error and increase in response time (RT) when participants reported their best-remembered item compared with trials in which they were randomly cued. These results demonstrate that participants can accurately introspect the relative quality of neural WM representations for spatial position, consistent with previous observations for other stimulus features, and support a model of WM coding involving noisy representations across items and trials.
工作记忆（WM）是一种在环境中无法获取信息时维持和操作信息的能力。大脑通过在嘈杂的群体激活模式中延迟期间维持 WM 表示，从而导致 WM 表示在项目和试验之间的变异性。已经确立，参与者可以内省 WM 表示质量的某些方面，并且他们可以准确地比较在每次试验中哪种刺激特征（如方向或颜色）的 WM 表示更好。然而，这种评估和比较多个 WM 表示质量的能力是否扩展到空间 WM 任务尚不清楚。在这里，我们使用了记忆引导的眼跳任务来测试参与者在允许选择最精确的报告表示时对记住的空间位置的回忆错误。参与者在延迟期间记住一个或两个空间位置，并通过眼跳报告一个项目的位置。在有两个空间位置的试验中，参与者要么报告随机提示项目的空间位置，要么报告他们记得最好的刺激的位置。与他们随机提示的试验相比，当参与者报告他们记得最好的项目时，我们发现回忆错误显著减少，反应时间（RT）增加。这些结果表明，参与者可以准确地内省空间位置的神经 WM 表示的相对质量，与先前对其他刺激特征的观察结果一致，并支持涉及项目和试验中噪声表示的 WM 编码模型。
