Post-decision biases reveal a self-consistency principle in perceptual inference

• Published in: eLife Vol. 7
• Main Authors: Luu, Long, Stocker, Alan A
• Format: Journal Article
• Language: English
• Published: England eLife Sciences Publications, Ltd 22.05.2018; eLife Sciences Publications Ltd
• Subjects: Bayesian inference; Bias; bounded rationality; Brain - physiology; Computational and Systems Biology; Decision Making; Female; Humans; Judgment; Male; Models, Neurological; Neuroscience; Orientation, Spatial; perception; Photic Stimulation; Visual Perception; computational biology; systems biology; bounded rationality; decision-making; neuroscience; bias; Bayesian inference; human; perception
• ISSN: 2050-084X; 2050-084X
• DOI: 10.7554/eLife.33334

Making a categorical judgment can systematically bias our subsequent perception of the world. We show that these biases are well explained by a self-consistent Bayesian observer whose perceptual inference process is causally conditioned on the preceding choice. We quantitatively validated the model and its key assumptions with a targeted set of three psychophysical experiments, focusing on a task sequence where subjects first had to make a categorical orientation judgment before estimating the actual orientation of a visual stimulus. Subjects exhibited a high degree of consistency between categorical judgment and estimate, which is difficult to reconcile with alternative models in the face of late, memory related noise. The observed bias patterns resemble the well-known changes in subjective preferences associated with cognitive dissonance, which suggests that the brain’s inference processes may be governed by a universal self-consistency constraint that avoids entertaining ‘dissonant’ interpretations of the evidence.