Distinct encoding of decision confidence in human medial prefrontal cortex

Area of Science:

• Neuroscience
• Cognitive Science
• Decision Making

Background:

• Confidence and evidence are often perceived as linked in decision-making.
• Computational models suggest separate neural estimates for confidence and evidence are crucial for adaptive behavior.

Purpose of the Study:

• To experimentally decouple subjective confidence from sensory evidence reliability and choice boundary proximity.
• To identify neural correlates of decision confidence distinct from sensory evidence processing.

Main Methods:

• A novel psychophysical task was designed to isolate confidence.
• Human functional magnetic resonance imaging (fMRI) was employed to measure brain activity during the task.
• Analysis focused on activity in the perigenual anterior cingulate cortex (pgACC), posterior parietal cortex, ventral striatum, and presupplementary motor area.

Main Results:

• The pgACC tracked expected performance, a measure of decision confidence.
• Areas like the posterior parietal cortex and ventral striatum encoded sensory reliability.
• The presupplementary motor area encoded proximity to the choice boundary.
• pgACC activity correlated with explicit confidence ratings, supporting its role in subjective confidence.

Conclusions:

• The brain appears to maintain distinct neural representations for decision confidence and sensory evidence.
• The pgACC is a key region for encoding decision confidence, separate from sensory information.
• Findings shed light on the neural basis of confidence and its dysfunction in conditions affecting the prefrontal cortex.