Background: The neural correlates of hypnosis remain incompletely characterized despite recognition of its clinical utility. Examining functional connectivity changes in large-scale brain networks during hypnosis can provide insights into cognitive control, dissociation, and self-awareness while guiding optimized clinical use cases across various conditions.

Objectives: This study aimed to systematically review fMRI studies of hypnosis, qualitatively synthesize evidence regarding its impact on connectivity within and between the default mode, salience, and executive control networks, and offer recommendations for future research by identifying gaps and inconsistencies in existing literature and methodology.

Methods: PubMed, PsycINFO, Scopus and Web of Science and other databases were systematically searched for fMRI studies on hypnosis. Peer-reviewed articles written in English were screened against eligibility criteria. Study data were extracted into a standardized form and quality assessed using a Newcastle-Ottawa Scale. A qualitative synthesis was performed focused on hypnosis effects on connectivity within and between the default mode, salience, and central executive networks.

Results: 35 experimental studies met inclusion criteria (n=689 participants). The review found heterogeneous effects on network connectivity during hypnosis, with both increased and decreased connectivity reported depending on suggestions used. The evidence indicates potential therapeutic effects for pain and anxiety, but overall direct clinical support was limited. Preliminary findings suggest hypnosis impacts connectivity between salience/executive control networks, enhancing top-down regulation of interoception and affect. Reduced connectivity was also reported within default mode regions involved in internal mentation like the posterior cingulate cortex and precuneus.

Conclusions: While the literature exhibits variability in protocols and results, findings overall indicate that hypnosis exerts top-down influence on internal mentation, attentional control, and emotional processing through altering functional interactions between cortical and subcortical brain regions. Inconsistencies arising from methodological variations and study heterogeneity constrain definitive conclusions. Addressing these limitations through standardized protocols and comparisons based on universal large scale brain network taxonomy would strengthen the evidence for the neural signature of hypnosis and enhance its applicability in various contexts.