Metacognition refers to the ability to monitor and introspect upon cognitive performance. Abundant research suggests that individual metacognition is easily affected by feedback in daily life, but how feedback affects metacognition in perceptual decision-making remains unclear. Here we investigated how trial-by-trial feedback shapes perceptual metacognition in two experiments with either high (n = 82) or low difficulty (n = 90). Participants were randomly divided into a feedback group in which participants received trial-by-trial performance feedback or a no-feedback group. Results showed that, in the high-difficulty task, participants in the feedback group revealed inferior metacognitive performance than the no-feedback group, manifested as decreased metacognitive efficiency while controlling for performance sensitivity. In the low-difficulty task, however, participants in the feedback group had higher metacognitive efficiency than the no-feedback group. The distinct patterns of findings in the two experiments indicate that whether feedback promotes or impedes metacognition is adjusted by task difficulty.

元认知是指监控和反思认知表现的能力。大量研究表明，个体元认知很容易受到日常生活中反馈的影响，但反馈如何影响感知决策中的元认知仍不清楚。在这里，我们在两个高难度（n = 82）或低难度（n = 90）的实验中研究了逐次试验反馈如何塑造感知元认知。参与者被随机分为反馈组和无反馈组，其中参与者收到逐次试验的表现反馈。结果表明，在高难度任务中，反馈组的参与者表现出比无反馈组较差的元认知表现，表现为在控制表现敏感性的情况下元认知效率下降。然而，在低难度任务中，反馈组的参与者比无反馈组的元认知效率更高。两个实验的不同发现模式表明，反馈是否促进或阻碍元认知是根据任务难度进行调整的。