Talk: Neural representations of social placebo effect

Speaker: Xinyuan Yan, Beijing Normal University (grid.20513.35)
Title: Neural representations of social placebo effect
Emcee: Valentina Borghesani
Backend host: Ali Rigby
Presented during Neuromatch Conference 3.0, Oct 26-30, 2020.

Summary: Abstract
Knowing the efficacy of administrated treatment is critical for inducing placebo effect. For example, giving treatment with full information could enable better therapeutic effect than just administrating treatment in hidden way. Even fake pill with “effective” descriptions would produce therapeutic-like effects. One fascinating question would be: how human brain could encode and represent treatment-related information to generate placebo responses? In the current study, we answered this question within the framework of social placebo effect (SPE), a latest placebo effect that can facilitate social functioning. Specifically, we examined the spontaneous representation and information-based representation by adopting resting-state and concepts representation task. Behavioral measurement was also adopted to confirm the placebo responses. We found that the spontaneous representation for treatment information has enhanced functional connectivity within social brain network, as well as between vmPFC and superior frontal gyrus. Further, in concepts representation task, treatment’s efficacy was represented in vmPFC, left middle frontal, right lateral orbitofrontal cortex with more distinct and finer-grained pattern in placebo condition. Finally, combing neural indices and behavioral indices, participants in placebo condition can be discriminated from control condition with a classification accuracy of 89%. Our study revealed the potential neural mechanisms for explaining why giving treatment information would induce placebo effect in multiple perspectives. These findings may further contribute to the way to manipulate effectiveness of treatment in clinical practice.