Confidence in memory's accuracy

Abstract

Despite accounts of a consistent and strong association between confidence and memory accuracy, they can be shown to dissociate. That belief in the truth of a memory may be influenced more by our metacognitive judgments of the memory’s quality (vividness or distinctiveness) than its factual accuracy was tested using real-world colour natural scenes photographs as retrieval cues in a continuous-response source memory task. Importantly, the correlation between memory quality and confidence was very large. Reducing the visual vividness of the images did not affect this very large correlation. Displaying pictures in a homogenous list arrangement (where all pictures represented the same natural scene category) reduced performance and memory accuracy but did not disrupt the very large correlation between distinctiveness and confidence. The correlation between accuracy and confidence remained moderate to large throughout. The relationship between accuracy and confidence was moderated by the vividness or distinctiveness of the memory, increasing confidence in the memory for the same level of accuracy, causing them to dissociate. The association between memory quality and accuracy acted largely indirectly, mediated through confidence. A 2-AFC recognition memory task, also using natural scenes photographs, reproduced the very large correlation between vividness and confidence. Remembering moderated the relationship between vividness and confidence, remembering being associated with higher confidence and higher vividness. Increases in the proportion of correct responses associated with remembering was seen only at highest levels of confidence. The 2-AFC task revealed a very large correlation between familiarity and confidence. Recollection was of less importance for accuracy when familiarity was high and of more importance when familiarity was low. The quality of a memory is associated with confident recollection, even if the detail is incorrect. The findings have implications for theoretical accounts of eyewitness testimony, illusions of memory accuracy, false memories, and dual process theory.