The timing of confidence computations in human prefrontal cortex

Area of Science:

• Cognitive Neuroscience
• Computational Neuroscience

Background:

• Understanding the timing of confidence computations is vital for elucidating the neural and computational underpinnings of metacognition.
• While neural correlates of confidence judgments are studied, the temporal dynamics remain largely unknown.

Approach:

• Participants judged visual stimulus orientation and rated confidence.
• Transcranial magnetic stimulation (TMS) was applied to the dorsolateral prefrontal cortex (DLPFC) or vertex at various post-stimulus times.
• Effects on accuracy, metacognitive ability, and confidence were assessed.

Key Points:

• TMS to DLPFC, but not vertex, significantly increased confidence.
• This increase in confidence occurred without altering accuracy or metacognitive ability.
• The effect was consistent for TMS delivered between 200 and 500 ms post-stimulus.

Conclusions:

• Confidence computations occur over a broad temporal window, starting before perceptual decisions are fully formed.
• These findings provide critical constraints for computational models of confidence generation.
• The dorsolateral prefrontal cortex (DLPFC) plays a key role in the timing of confidence computations.