Evaluating the effects of a conditioning training paradigm on loneliness, socio-affective processing, and brain connectivity: a study protocol of a two-arm randomised controlled trial

Abstract

Background: Loneliness has become a global epidemic and is a significant threat to people’s health. Existing interventions for loneliness often attempt to increase opportunities for social activities, but results are mixed. Here, we will use a two-arm randomised controlled trial and evaluate the effects of a novel training paradigm grounded in the principles of evaluative conditioning to change their socio-affective processing, brain connectivity, and reduce loneliness. Methods: We aim to recruit 180 lonely individuals and randomly allocate them into either the evaluative conditioning group or the control group. They will receive six 30-minute training sessions online over the course of three weeks. Behavioural and MRI assessments will be conducted at baseline, immediately after, and 3 months after the intervention. The primary outcomes will be self-reported loneliness and implicit loneliness. Secondary outcomes will include functional brain connectivity, emotional processing and social motivation, anxiety and depression levels, emotional state and reactivity, social network, and social support. We will investigate the intervention effects and evaluate whether emotional processing and brain connectivity are the mediators. Discussion: This study will provide important evidence for the intervention effects of conditioning on loneliness at both behavioural and neural levels, contributing to the development of a real-life loneliness intervention model. Trial registration: ClinicalTrials.gov, NCT06521099. Registered on July 2024.