Differently confident: Susceptibility to bias in perceptual judgments of size interacts with working memory capacity

Much prior research has shown that retrieval of information from long-term memory (LTM) can influence many aspects of complex cognition in situ. However, research also has shown that not all individuals manage information retrieved from LTM in equivalent fashions. Specifically, high working memory capacity (WMC) individuals have been shown to be better able to manage not only what information is retrieved from LTM, but also whether it is applied to the task-at-hand. As such, it is likely that WMC will interact with the biasing influences of prior knowledge on current task performance. In this series of studies, high and low WMC individuals were asked to make perceptual judgments of size that either did or did not activate biasing prior knowledge. Results indicate that when retrieving information from LTM, high WMC individuals are actually more susceptible to perceptual bias and also are erroneously more confident in the accuracy of their response. However, when no retrieval from LTM is necessary, this effect reverses. This suggests that high WMC individuals are indeed able to inhibit such biasing information; however, their overconfidence in the quality of information retrieved from their own LTM can make them susceptible to making errors in perceptual judgments.