Abstract
This study examined whether i) brief videos aiming to optimize outcome expectations would augment the efficacy of progressive muscle relaxation (PMR) and ii) whether participants’ characteristics would moderate these effects. Sixty-eight healthy subjects randomized to one of three experimental manipulations before undergoing a single PMR session either watched i) a video displaying a neutral expert, ii) a video with a warm expert, or iii) were part of an active control condition. Constrained linear mixed models indicated increased relaxation and decreased stress levels for all participants after the PMR session. The primary outcome was the change of perceived relaxation/stress from pre to post. Participants with high neuroticism and trait anxiety indicated an augmented PMR’s efficacy and increased outcome expectations when watching the warm expert video compared to the control group or the less warm expert. Brief videos displaying an expert aiming to optimize outcome expectations regarding a brief stress-reducing psychological intervention may boost or decrease an intervention’s efficacy. Effects may depend on the viewer’s personality and the (video) expert’s communication style.
This article is protected by copyright. All rights reserved.