Related Experiment Videos
Flavour liking and preference conditioned by caffeine in humans
Martin R Yeomans1, Paula J Durlach, Elizabeth M Tinley
1Department of Psychology, School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK. martin@sussex.ac.uk
Summary
Repeatedly consuming a novel drink with caffeine increases its pleasantness. This Pavlovian conditioning, where the drink flavor predicts caffeine
Area of Science:
- Neuroscience
- Psychology
- Behavioral Science
Background:
- Previous studies suggest flavor pleasantness increases with caffeine consumption.
- These findings were based on between-subjects designs, raising concerns about nonspecific effects.
- A more rigorous within-subjects design is needed to confirm Pavlovian conditioning.
Purpose of the Study:
- To rigorously test if flavor pleasantness increases due to Pavlovian conditioning with caffeine.
- To differentiate between caffeine's effects and nonspecific influences on flavor preference.
Main Methods:
- Twenty moderate caffeine consumers participated in an eight-trial within-subjects study.
- Participants consumed two novel drinks: one paired with caffeine (CS+) and one with placebo (CS-).
- Drink pleasantness and sensory characteristics were evaluated after each trial.
Main Results:
- The pleasantness of the caffeine-paired drink (CS+) significantly increased over trials.
- The pleasantness of the placebo-paired drink (CS-) showed no significant change.
- Despite increased pleasantness, no overall preference for the CS+ flavor emerged post-training.
Conclusions:
- The results strongly support Pavlovian conditioning as the mechanism for increased flavor pleasantness.
- Flavor-drink associations with caffeine's postingestive effects drive pleasantness changes.
- Baseline preferences can obscure overall changes in flavor preference despite conditioning.