Structural differences in the cortex of individuals who experience the autonomous sensory meridian response

Abstract

Background and purpose: The autonomous sensory meridian response (ASMR) is a multimodal perceptual phenomenon in which specific sensory triggers evoke tingling sensations on the scalp, neck, and shoulders; these sensations are accompanied by a positive and calming affective state. Previous functional neuroimaging research has shown that ASMR experiences involve medial prefrontal and sensorimotor brain areas. The purpose of the current study was to examine whether there are structural differences in the cortex of individuals who experience ASMR. Methods: Seventeen individuals with ASMR and 17 matched control participants completed an MPRAGE structural MRI scan. These data were analyzed to determine if group differences were present for measures of cortical thickness, cortical complexity, sulcal depth, and gyrification. Results: ASMR was associated with reduced cortical thickness in a number of regions including the left precuneus, precentral gyrus, and insula, and the right orbitofrontal cortex, superior frontal cortex, and paracentral lobule. Reduced thickness was observed bilaterally in the supramarginal gyrus. Individuals with ASMR also showed less cortical complexity in the pars opercularis and pars triangularis. Conclusions: The differences in cortical thickness and complexity were in brain areas whose functions relate to the ASMR experience. These differences include neural regions related to phonological processing, sensorimotor functions, and attention.