Zehetleitner, M. | Search bioRxiv

bioRxiv2019

Cognitive modelling reveals distinct electrophysiological markers of decision confidence and error monitoring

Is confidence in perceptual decisions generated by the same brain processes as decision itself, or does confidence require metacognitive processes following up on the decision? In a masked orientation task with varying stimulus-onset-asynchrony, we used EEG and cognitive modelling to trace the timing of the neural correlates of confidence. Confidence as reported by observers increased with stimulus-onset-asynchrony in correct and to a lesser degree in incorrect trials, a pattern incompatible with established models of confidence. Electrophysiological activity in two different time periods was associated with confidence, namely, 350 - 500 ms after stimulus onset and 250 - 350 ms after the response. Cognitive modelling revealed that only the activity following on the stimulus exhibited the same statistical regularities as confidence, while the statistical pattern of the activity following the response was not compatible with confidence. It is argued that electrophysiological markers of decision confidence and error awareness are at least in parts distinct.

neuroscience↗

bioRxiv2018

Multiple statistical signatures of human confidence

Recent studies have traced the neural correlates of confidence in perceptual choices using statistical signatures of confidence. The most widely used statistical signature is the folded X-pattern, which was derived from a standard model of confidence assuming an objective definition of confidence as the posterior probability of making the correct choice given the evidence. The folded X-pattern entails that confidence as the subjective probability of being correct equals the probability 0.75 if the stimulus in neutral about the choice options, increases with discriminability of the stimulus in correct trials, and decreases with discriminability in incorrect trials. Here, we show that the standard model of confidence is a special case in which there is no reliable trial-by-trial evidence about discriminability itself. According to a more general model, if there is enough evidence about discriminability, objective confidence is characterised by different pattern: For both correct and incorrect choices, confidence increases with discriminability. In addition, we demonstrate the consequence if discriminability is varied in discrete steps within the standard model: confidence in choices about neutral stimuli is no longer .75. Overall, identifying neural correlates of confidence by presupposing the folded X-pattern as a statistical signature of confidence is not legitimate.

neuroscience↗