Data from: A metacognitive illusion in monkeys

Like humans, monkeys can make accurate judgments about their own memory by reporting their confidence during cognitive tasks. Some have suggested that animals use associative learning to make accurate confidence judgments, while others have suggested animals directly access and estimate the strength of their memories. Here we test a third, non-exclusive possibility: perhaps monkeys, like humans, base metacognitive inferences on heuristic cues. Humans are known to use cues like perceptual fluency (e.g., how easy something is to see) when making metacognitive judgments. We tested monkeys using a match-to-sample task in which the perceptual fluency of the stimuli was manipulated. The monkeys made confidence wagers on their accuracy after each trial. We found that monkeys’ wagers were affected by perceptual fluency even when their accuracy was not. This is novel evidence that animals are susceptible to metacognitive illusions similar to those experienced by humans.

与人类相仿，猴子可在认知任务中通过报告自身信心，对自身记忆做出精准判断。部分研究者提出，动物借助联想学习做出精准的信心判断；另有观点认为动物可直接调取并评估自身记忆的强度。本研究旨在检验第三种非排他性可能性：或许与人类一样，猴子的元认知推理（metacognitive inferences）基于启发式线索（heuristic cues）。已知人类在进行元认知判断时，会借助诸如知觉流畅性（perceptual fluency，例如辨识事物的难易程度）这类线索。我们采用样例匹配任务（match-to-sample task）对猴子开展实验，该任务中刺激物（stimuli）的知觉流畅性被人为操控。每一轮试次结束后，猴子需针对自身判断的准确性做出信心下注。我们发现，即便猴子的判断准确性未受影响，其信心下注仍会受到知觉流畅性的调控。本研究为动物会遭遇与人类相似的元认知错觉（metacognitive illusions）提供了全新证据。