Distinct encoding of decision confidence in human medial prefrontal cortex

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 115; no. 23; pp. 6082 - 6087
• Main Authors: Bang, Dan, Fleming, Stephen M.
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 05.06.2018
• Subjects: Adaptive control; Adult; Biological Sciences; Brain; Brain - physiology; Brain mapping; Brain Mapping - methods; Choice Behavior - physiology; Coding; Computational neuroscience; Confidence intervals; Cortex (cingulate); Cortex (parietal); Decision making; Decision Making - physiology; Degeneration; Estimates; Female; Functional magnetic resonance imaging; Gyrus Cinguli - physiology; Humans; Lesions; Magnetic Resonance Imaging - methods; Male; Neostriatum; Neurodegeneration; Prefrontal cortex; Prefrontal Cortex - physiology; Presupplementary motor area; Psychophysics; Reliability; Reproducibility of Results; Somatosensory cortex; fMRI; medial prefrontal cortex; confidence; decision making
• ISSN: 0027-8424; 1091-6490; 1091-6490
• DOI: 10.1073/pnas.1800795115

Our confidence in a choice and the evidence pertaining to a choice appear to be inseparable. However, an emerging computational consensus holds that the brain should maintain separate estimates of these quantities for adaptive behavioral control. We have devised a psychophysical task to decouple confidence in a perceptual decision from both the reliability of sensory evidence and the relation of such evidence with respect to a choice boundary. Using human fMRI, we found that an area in the medial prefrontal cortex, the perigenual anterior cingulate cortex (pgACC), tracked expected performance, an aggregate signature of decision confidence, whereas neural areas previously proposed to encode decision confidence instead tracked sensory reliability (posterior parietal cortex and ventral striatum) or boundary distance (presupplementary motor area). Supporting that information encoded by pgACC is central to a subjective sense of decision confidence, we show that pgACC activity does not simply covary with expected performance, but is also linked to within-subject and between-subject variation in explicit confidence estimates. Our study is consistent with the proposal that the brain maintains choice-dependent and choice-independent estimates of certainty, and sheds light on why dysfunctional confidence often emerges following prefrontal lesions and/or degeneration.