Related Experiment Video
Updated: Jun 2, 2026
08:50
How to Study Placebo Responses in Motion Sickness with a Rotation Chair Paradigm in Healthy Participants
Published on: December 14, 2014
Motivation and placebos: do different mechanisms occur in different contexts?
1School of Psychology, University of Plymouth, Plymouth PL4 8AA, UK. mhyland@plymouth.ac.uk
Summary
Short-term placebo effects stem from response expectancy and conditioning. Long-term therapeutic changes involve goal satisfaction impacting the inflammatory response and hypothalamic-pituitary-adrenal axis.
Area of Science:
- Psychology
- Neuroscience
- Medicine
Background:
- Common assumption: short-term and long-term placebo mechanisms are identical.
- Short-term paradigms lack motivation for health improvement.
- Long-term paradigms involve patient valuation of health improvement.
Purpose of the Study:
- Challenge the assumption of identical placebo mechanisms.
- Review motivational theories of placebo effects.
- Propose a new theory differentiating short-term and long-term placebo mechanisms.
Main Methods:
- Review of three motivational theories: classical placebo motivation, goal activation model, and motivational concordance model.
- Analysis of current data to support a new theoretical framework.
- Outline empirical predictions for the proposed theory.
Main Results:
- Short-term placebo effects are attributed to response expectancy, conditioning, and goal activation.
- Long-term therapeutic change is linked to goal satisfaction and affect.
- These effects modulate the inflammatory response system and hypothalamic-pituitary-adrenal axis.
Conclusions:
- Short-term and long-term placebo mechanisms differ significantly.
- A new theory integrates motivational and physiological pathways.
- Potential for combining placebo effects with other psychological interventions is highlighted.
Related Concept Videos
01:54The Placebo Effect
The placebo effect occurs when people's expectations or beliefs influence or determine their experience in a given situation. In other words, simply expecting something to happen can actually make it happen.
02:07Blind Procedures
Ideally, the people who observe and record the children’s behavior are unaware of who was assigned to the experimental or control group, in order to control for experimenter bias. Experimenter bias refers to the possibility that a researcher’s expectations might skew the results of the study. Remember, conducting an experiment requires a lot of planning, and the people involved in the research project have a vested interest in supporting their hypotheses. If the observers knew which child was...
01:18Incentive Theory: Pull Theory of Motivation
Incentive theory, or the "pull theory" of motivation, suggests that external rewards primarily drive behavior. Individuals are motivated to engage in activities when they anticipate a desirable outcome. This is why people often work hard for promotions or study intensively to achieve high grades. These incentives can be tangible, physical rewards such as money or promotions, or intangible, non-physical rewards like praise and social recognition.
The theory differentiates between intrinsic and...
The theory differentiates between intrinsic and...
01:17Classical Conditioning in Daily Life
Classical conditioning, a fundamental principle of associative learning, explains various phenomena observed in daily life, such as fear development, the placebo effect, taste aversion, and drug habituation. These applications demonstrate the profound impact of associative learning on human behavior and physiological responses.
John B. Watson and Rosalie Rayner famously demonstrated the development of fear through classical conditioning in their experiment with Little Albert. They paired the...
John B. Watson and Rosalie Rayner famously demonstrated the development of fear through classical conditioning in their experiment with Little Albert. They paired the...
01:11Blinding
Blinding is a commonly used method of not telling participants which treatment a subject is receiving. Blinding is a critical part of a randomized control trial or RCT. It reduces the bias that affects the results. In an RCT, blinding is used in the form of a placebo. A placebo effect occurs when untreated subjects falsely believe they have received the treatment and report improved symptoms. A placebo or a dummy treatment is administered to subjects to negate the bias caused by such an effect.
01:22Purposive Learning
E. C. Tolman emphasized the purposiveness of behavior — the idea that much of our behavior is goal-directed. For instance, employees who aim for a promotion work diligently to meet their targets. Tolman argued that when classical conditioning and operant conditioning occur, the organism acquires certain expectations. In classical conditioning, a child might fear a dog because they expect it to bite. In operant conditioning, a person might consistently work overtime because they expect a bonus...