Understanding the Mechanisms And Benefits of Autonomous Sensory Meridian Response (ASMR) Consumption: a Systematic Review.

Aim: To summarize the ASMR intervention studies and the approaches to examine objective parameters and potential benefits. Materials and Methods: A search strategy was performed in Scopus, Web of Science, MEDLINE, EMBASE, and Google Scholar following the PRISMA statements and was registered in PROSPERO (CRD42021228070). Studies in which ASMR intervention was included or compared with controls were selected. Results: twenty-eight studies (27 healthy and 1 depression participants) were included. Many studies have incomplete data. Specific patterns of MRI and EEG components were found. Specifically, nucleus accumbens, dorsal anterior cingulate gyrus, insula, and inferior frontal gyrus, decreased functional connectivity between the dorsolateral prefrontal cortex (dlPFC) and posterior cingulate cortex (PCC), diminished connectivity in the left precuneus, default mode network (DMN) with reduced functional connectivity. In EEG the results vary among increased alpha power in the left frontal, left parietal, and right parietal, and near the precuneus; an increase in gamma power in sensorimotor regions, a declined delta band power in the right frontal region, a decreased alpha power in occipital, while alpha and gamma power increased in the central areas. Conclusion: This review attempts to understand the designs and future implications of a novel therapeutic tool. The inconsistency of the ASMR intervention and control design, the various questionnaires assessing the condition, the contrasting risk of bias among studies, the lack of ethnic diversity of the participants, and the mostly subjective self-reported sensations, made this systematic review highly heterogeneous. This, in turn, impacts the generalization of the benefits and neurological components.