A transferable anxiolytic placebo effect from noise to negative effect.

BACKGROUND The placebo effect in relieving negative emotion arousal is poorly understood. AIMS We examined whether placebo expectation established with noise stimuli could have a transferable anxiolytic effect on negative emotion arousal. METHODS In Experiment 1, noise intensity was surreptitiously lowered during placebo condition in the preconditioning phase to reinforce placebo expectation, and the noise-relieving placebo effect was assessed in the testing phase. In Experiment 2, the same manipulation as in Experiment 1 was administered in the preconditioning phase, but the anxiolytic placebo effect was assessed in the testing phase using negative pictures. RESULTS Intensity and annoyance by the noise in Experiment 1 were significantly reduced, and unpleasantness in Experiment 2 was also significantly reduced in the placebo condition. CONCLUSION Direct noise-relieving placebo effects and transferred anxiolytic placebo effects were found. The present study provides evidence that the placebo effect can be transferred from noise to emotion.