Reading focus
Syllabus: How Do We Perceive the World?
Use the tutorial to distinguish sensory evidence, response criterion, and the consequences of mistakes. The purpose is to explain why a change in reports need not mean a change in sensitivity.
A question to consider. A station announcement becomes more important to a listener, who now reports hearing it more often. Which counts would you collect to determine what changed?
Why this reading
A person can report more signals without becoming better at distinguishing them. This tutorial separates sensitivity from response bias, then asks how the costs of mistakes change an appropriate decision rule.
Before you read
A hit is a detected target; a false alarm is a target report when the target is absent. Sensitivity describes how distinguishable the alternatives are. A criterion sets how much evidence is needed for a response. Utility means the value assigned to an outcome within a model, not a judgment of moral worth.
Read for
- Compare changes in sensitivity with movements of the response criterion.
- Follow how target frequency and payoffs alter the criterion that maximizes expected utility.
- Use the figures to explain why accuracy and utility can favor different responses. Distinguish the model’s prediction from observed behavior.
Consider afterwards
- A listener reports more faint tones after missed signals become costly. Which response counts would distinguish improved sensitivity from a changed criterion?
Editorial context
The tutorial includes modeling and reanalysis of earlier emotion-perception data. Its optimality claims depend on specified probabilities and payoffs. Real situations may not supply those values, and a fitted decision model does not by itself identify a neural mechanism.