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Related Experiment Video

Updated: Feb 11, 2026

How to Study Placebo Responses in Motion Sickness with a Rotation Chair Paradigm in Healthy Participants

How to Study Placebo Responses in Motion Sickness with a Rotation Chair Paradigm in Healthy Participants

Published on: December 14, 2014

Response Expectancy and the Placebo Effect.

Irving Kirsch¹

¹Harvard Medical School, Boston, MA, United States.

International Review of Neurobiology

|April 24, 2018

Summary

This summary is machine-generated.

Response expectancies, beliefs about outcomes, strongly influence experiences and are key to understanding placebo effects. These expectancies are more potent and enduring than stimulus expectancies, aligning with predictive coding models.

Keywords:

Automaticity Placebo effects Predictive coding Response expectancy Stimulus expectancy

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Last Updated: Feb 11, 2026

How to Study Placebo Responses in Motion Sickness with a Rotation Chair Paradigm in Healthy Participants

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Area of Science:

Psychology
Cognitive Science
Neuroscience

Background:

Response expectancy theory explains how beliefs about outcomes shape experiences.
Distinguishes between response expectancies and stimulus expectancies.

Purpose of the Study:

To review the fundamental principles of response expectancy theory.
To highlight the significance of response expectancies in placebo effects.
To connect response expectancies with the Bayesian model of predictive coding.

Main Methods:

Review of existing literature on response expectancy theory.
Conceptual analysis comparing response and stimulus expectancies.
Integration with Bayesian predictive coding frameworks.

Main Results:

Response expectancies exert stronger and more persistent effects than stimulus expectancies.
Response expectancies are crucial for understanding placebo phenomena.
The response expectancy framework is supported by and extends the Bayesian model of predictive coding.

Conclusions:

Response expectancies are a powerful determinant of psychological and physiological experiences.
Understanding response expectancies has significant clinical implications, particularly for placebo effects.
The integration with predictive coding offers a neurobiological basis for expectancy effects.