Samaha Jason, Denison Rachel
Department of Psychology, University of California, 1156 High St, Santa Cruz, CA 95064, USA.
Department of Psychological and Brain Sciences, Boston University, 64 Cummington Mall, Boston, MA 02215, USA.
Neurosci Conscious. 2022 Jul 26;2022(1):niac010. doi: 10.1093/nc/niac010. eCollection 2022.
Confidence in a perceptual decision is a subjective estimate of the accuracy of one's choice. As such, confidence is thought to be an important computation for a variety of cognitive and perceptual processes, and it features heavily in theorizing about conscious access to perceptual states. Recent experiments have revealed a "positive evidence bias" (PEB) in the computations underlying confidence reports. A PEB occurs when confidence, unlike objective choice, overweights the evidence for the correct (or chosen) option, relative to evidence against the correct (or chosen) option. Accordingly, in a perceptual task, appropriate stimulus conditions can be arranged that produce selective changes in confidence reports but no changes in accuracy. Although the PEB is generally assumed to reflect the observer's perceptual and/or decision processes, post-decisional accounts have not been ruled out. We therefore asked whether the PEB persisted under novel conditions that addressed two possible post-decisional accounts: (i) post-decision evidence accumulation that contributes to a confidence report solicited after the perceptual choice and (ii) a memory bias that emerges in the delay between the stimulus offset and the confidence report. We found that even when the stimulus remained on the screen until observers responded, and when observers reported their choice and confidence simultaneously, the PEB still emerged. Signal detection-based modeling showed that the PEB was not associated with changes to metacognitive efficiency, but rather to confidence criteria. The data show that memory biases cannot explain the PEB and provide evidence against a post-decision evidence accumulation account, bolstering the idea that the PEB is perceptual or decisional in nature.
对感知决策的信心是对个人选择准确性的主观估计。因此，信心被认为是各种认知和感知过程中的一项重要计算，并且在关于有意识地获取感知状态的理论中占据重要地位。最近的实验揭示了信心报告背后的计算中存在“积极证据偏差”（PEB）。当信心与客观选择不同，相对于不利于正确（或所选）选项的证据，过度重视正确（或所选）选项的证据时，就会出现PEB。因此，在感知任务中，可以安排适当的刺激条件，这些条件会导致信心报告产生选择性变化，但准确性不变。尽管通常认为PEB反映了观察者的感知和/或决策过程，但尚未排除决策后因素的解释。因此，我们询问在解决两种可能的决策后因素解释的新条件下，PEB是否仍然存在：（i）决策后证据积累，这有助于在感知选择后引发的信心报告；（ii）在刺激消失与信心报告之间的延迟中出现的记忆偏差。我们发现，即使刺激一直保留在屏幕上直到观察者做出反应，并且观察者同时报告他们的选择和信心，PEB仍然会出现。基于信号检测的建模表明，PEB与元认知效率的变化无关，而是与信心标准有关。数据表明，记忆偏差无法解释PEB，并提供了反对决策后证据积累解释的证据，支持了PEB本质上是感知或决策性的观点。
