Background & Aims

Placebo and nocebo effects can be acquired through direct pain experiences or by observing others’ pain-related behaviors (Bajcar & B?bel, 2018). While there is evidence of a relationship between brain activity and these effects, still little is known about structural brain differences in people who respond to placebo and nocebo with different magnitudes. This study aimed to bridge this gap by comparing the brain structure and the strength of placebo hypoalgesia and nocebo hyperalgesia when induced through observational learning. Furthermore, the study explores how psychological traits influence the development of these observationally learned placebo and nocebo responses.

Methods

Participants (n=190) underwent an experimental procedure and MRI scanning on two different occasions. During the experimental procedure, placebo and nocebo effects were elicited by observational learning. Participants received thermal stimuli applied to both forearms, one covered with a placebo ointment and the other with a nocebo one. The procedure consisted of pretest, cream application, observational learning phase and posttest. In the pretest and posttest, participants rated experienced pain intensity on the Numerical Rating Scale (NRS). Also, participants’ pain expectations were measured on the NRS after the observational learning phase. Additionally, participants filled out a battery of questionnaires testing individual traits.

Results

Both behavioral and magnetic resonance imaging (MRI) data analysis is still ongoing and the results will be presented at the congress.

Conclusions

Identification of brain structures related to placebo effects could lead to the development of new treatments that harness the placebos to enhance the efficacy of existing therapies. Deeper understanding of placebo effects induced by observational learning and their neuroanatomical determinants might contribute to a better understanding of how social information influences clinical setting treatment efficacy and can shed a light on developing novel tools for clinical practice.

References

Bajcar, E. A., & B?bel, P. (2018). How does observational learning produce placebo effects? A model integrating research findings. Frontiers in psychology, 9, 2041.

Presenting Author

Helena Bieniek

Poster Authors

Karolina Wiercioch-Kuzianik

PhD

Institute of Psychology, Jagiellonian University in Kraków

Lead Author

Justyna Br?czyk

Jagiellonian University

Lead Author

Helena Bieniek

Jagiellonian Univeristy

Lead Author

El?bieta A. Bajcar

PhD

Jagiellonian University

Lead Author

Stefanie dr. Meeuwis

Health, Medical, and Neuropsychology unit at Leiden University’s Institute of Psychology

Lead Author

Julia Badzinska

Jagiellonian University

Lead Author

Helena Hartmann

University Hospital Essen

Lead Author

Renate Rutiku

PhD

Lead Author

Przemys?aw B?bel

Prof.

Jagiellonian University, Institute of Psychology, Pain Research Group

Lead Author

Topics

  • Pain Imaging