On the edge of awareness: ictal consciousness and psychosis in focal epilepsy.

A confidence judgment about a current stimulus can be predicted from a previous confidence judgment about a different stimulus. This confidence serial dependence phenomenon is known as “confidence leak” (; ). Confidence leak is thought to occur across virtually any task and domain but nonetheless remains severely underexplored. In fact, it has been explicitly investigated in only five papers (; ; ; ; ) and one conference abstract (). The earliest investigation of confidence leak appears to be in a paper focused on providing evidence for decision noise in perceptual decision-making (). Mueller & Weidemann showed that subjects had a tendency to repeat the same confidence judgment in consecutive trials, which shows the existence of noise in the confidence criterion placement. The first paper specifically devoted to confidence serial dependence showed that confidence leaks across different perceptual tasks and different ways of indicating confidence, thus ruling out simple motor confounds (). Confidence leak was subsequently demonstrated within recognition memory and was even shown to occur across tasks from different domains (in this case memory and perception) (). Similarly, showed that a classifier trained on confidence serial dependence in one domain can predict confidence serial dependence in different domains. Finally, confidence leak has been shown to occur even when the previous trial did not require an explicit confidence judgment (). As the brief review above shows, while confidence leak has been established as a ubiquitous and robust phenomenon, it is still unclear whether the strength of the effect can be modulated. One particular source of modulation could be the motor action used to make a response. Indeed, both first-order choices and confidence judgments in simple psychophysical tasks are mediated by the action required to indicate the decision (; ; ; ; ; ; ; ). Some modulations of first-order choices include the motor effort () or the motor cost () of the action associated with the decision, where perceptual decisions associated with less costly actions are preferred. Confidence judgments have also been shown to depend on the perceptual-motor mapping of representations (; ; ). For example, TMS perturbations of premotor cortical regions influence confidence without affecting signal discrimination abilities (). Overall, motor actions have been shown to robustly affect confidence judgments, but whether or not they also modulate confidence serial dependence remains unknown.