A Comparative Study of Anterior Insula Real-time fMRI Neurofeedback Training Based on Unidimensional vs. Multidimensional Interoceptive Regulation Strategies

This study uses a randomized between-subject design to compare the efficacy of two interoceptive strategies in regulating anterior insula activity during real-time fMRI neurofeedback training. A total of 60 healthy participants are recruited and are randomly assigned to one of two groups. The heartbeat detection group (HDG; n = 30) uses a heartbeat detection strategy to upregulate anterior insula activity during neurofeedback training. The multidimensional interoception group (MIG; n = 30) uses a multidimensional interoception strategy which involves shifting attention among respiratory sensations, cardiac signals, gastric sensations, and bladder distension, to increase anterior insula activity during neurofeedback training. The neurofeedback protocol includes 4 training sessions with real-time neurofeedback and 1 transfer session without neurofeedback. Each session comprises 6 regulation (upregulate anterior insula activity with interoception strategies) blocks and 6 baseline (rest) blocks. Interoceptive accuracy is assessed using a heartbeat detection task performed before and after neurofeedback training. During MRI scanning, a heartbeat counting task will be employed prior to neurofeedback training to localize the anterior insula. The behavioral effects of neurofeedback training are evaluated using a pain empathy rating task and an interoception/relaxation rating task following the regulation or baseline block. Individual differences in personality traits and interoceptive characteristics are assessed using validated Chinese questionnaires, including State-Trait Anxiety Inventory (STAI), Beck Depression Inventory-Ⅱ (BDI-Ⅱ), Toronto Alexithymia Scale (TAS), Autism Spectrum Quotient (ASQ), Bermond-Vorst Alexithymia Questionnaire (BVAQ), Multidimensional Assessment of Interoceptive Awareness (MAIA), Interoceptive Confusion Questionnaire (ICQ), Interpersonal Reactivity Index (IRI), and Cognitive Flexibility Inventory (CFI). Affective moods are assessed using the Positive and Negative Affect Schedule (PANAS).