Reading focus
Syllabus: How Do We Perceive the World?
Compare the review’s explanations of expectation effects and its acknowledged disagreements. Use the opening signal-detection distinction to assess claims based on reports, and the recognition unit to assess claims based on neural representations.
A question to consider. Someone identifies a blurred object more accurately after a predictive cue. What would separate improved sensory evidence, a useful prior, attention, and a changed response rule?
Why this reading
Prior experience can help interpret uncertain sensory information. This review distinguishes evidence for expectation effects from the stronger claim that one computational or neural theory explains them.
Before you read
A prior expresses what is probable before current evidence is considered. A likelihood describes how compatible that evidence is with a proposed cause. Bayesian inference combines these; predictive coding is a proposed implementation, not a synonym. Expectation concerns what is likely, whereas attention concerns what is relevant.
Read for
- Track how sensory uncertainty and the reliability of expectations affect the proposed balance between them.
- Compare dampening and sharpening accounts of reduced neural responses to expected inputs.
- Distinguish findings consistent with predictive coding from tests that separate it from alternatives. Examine how attention and response decisions could affect a comparison.
Consider afterwards
- An expected image produces a smaller brain response but better identification. Which explanations remain possible, and what further measurement could separate them?
Editorial context
This is a 2018 synthesis of a developing debate. Neural response changes, reported experience, and decision performance are different evidence. The authors identify disagreements and underdetermined mechanisms; their clinical extensions are hypotheses, not diagnostic conclusions or established explanations of every condition.