The feeling of pain is not just a sensory experience, but is also influenced by emotions,
beliefs and expectations, making pain a highly subjective experience. This is evident in
clinical practice, where the behavior of the physician and the treatment context can strongly
influence the pain experience of patients. Research has shown that patients' expectation that
a treatment will reduce pain influences individual perception of pain, even if the treatment
has no active ingredient. The expectancy-induced analgesia emerges due to a modulation of the
individual pain experience of patients by an engagement of endogenous inhibitory systems in
the central nervous system.
The development of expectancy-induced analgesia can be generated in several ways. The
investigators have previously demonstrated that social information and observational learning
(e.g. the patient observes analgesia in another person receiving a treatment) can lead to
expectancy-induced analgesia and pain reduction. However, the neural mechanisms (mechanisms
in the brain) of how these expectancies are acquired and the neural mechanisms of analgesia
induced by observational learning are unknown.
The investigators recently established a procedure to investigate neural mechanisms of
observational learning in placebo analgesia. Here the investigators propose to investigate
the influence of vasopressin, a neurotransmitter that is important for social interaction, on
observational learning.
The investigators will use functional magnetic resonance imaging (fMRI), a non-invasive
method, to investigate neural activity in humans. Participants will either receive
vasopressin or saline with a nasal spray. During fMRI scanning, participants will then
undergo an observational learning phase, where the study participants will learn the
experience of analgesia in another person through a video, and a testing phase, where
participants will perceive painful stimulations with the same cues as the observational
phase. The comparison of the vasopressin group and the saline group will allow us to
investigate how vasopressin influences behavioral effects of observational learning on pain
perception as well as its effect on the neural processing of observational learning.
A better understanding of how the human brain processes observationally-induced analgesia
would allow us to improve the therapeutic context of pain treatments by increasing the
contextual factors which help patients cope with pain.
Phase:
Phase 1/Phase 2
Details
Lead Sponsor:
University of Maryland University of Maryland, Baltimore