Fig. 1
From: Different brain networks mediate the effects of social and conditioned expectations on pain
Design and results. a Design. The social information could be either low or high on average (SocialLOW or SocialHIGH), but was not correlated with actual heat intensity. In contrast, the learning cues (CSLOW and CSHIGH,) were followed by low-to-medium or medium-to-high heat intensity, respectively. b Each trial started with the simultaneous presentation of social information (“pain ratings of previous participants”, depicted as vertical lines on a VAS) and one of the CS (animal or vehicle drawing). Participants then rated their pain expectation, received a short heat pain stimulation, and rated how much pain they experienced. c Effects on behavior, physiology, and brain patterns. Violinplots show the effects for SocialHIGH > SocialLOW and CSHIGH > CSLOW. Each dot reflects the beta (effect magnitude) estimate of one participant. Both social information and CS significantly influenced expectation (social information: t(35) = 10.65, p < 0.001, CS: t(35) = 3.02, p = 0.005) and pain ratings (social: t(35) = 6.19, p < 0.001, CS: t(35) = 3.13, p = 0.003). Skin conductance responses (SCR) were significantly modulated by social information (t(35) = 2.04, p = 0.049), but not by CS. Neither NPS nor SIIPS showed significant responses to social information or CS. Asterisks denote significant effects at p < 0.05 (using t tests). d, e Time course of expectation and pain ratings. The difference between dotted and solid lines reflects the CS effect, and the difference between gray and black lines the social information effect. CS effects on expectation and pain increased over time (interaction effects CS*Time on expectation: t(35) = 3.02, p = 0.004, on pain: t(35) = 2.03, p = 0.049). Social information effects on expectations and pain remained significant throughout the experiment, but decreased over time for expectation ratings (Social × Time on expectations: t(35) = −4.57, p < 0.001). The x-axis shows trials per condition. f Behavioral mediation analysis. Expectation ratings significantly mediated both Social (t(35) = 8.56, p < 0.001) and CS effects on pain (t(35) = 3.27, p < 0.001). Source data for panels c, d, and e are provided as a Source Data file
