Alterations in cerebral glucose metabolism measured by FDG PET in subjects performing a meditation practice based on clitoral stimulation

Abstract

Background: The relationship between sexuality, or the libido, and spirituality or religion has long been debated in psychiatry. Recent studies have explored the neurophysiology of both sexual experiences and spiritual practices such as meditation or prayer. In the present study, we report changes in cerebral glucose metabolism in a unique meditation practice augmented by clitoral stimulation called, Orgasmic Meditation, in which a spiritual state is described to be attained by both male and female participants engaged in the practice as a pair. Methods: Male (N=20) and female (N=20) subjects had an intravenous catheter connected to a bag of normal saline inserted prior to the practice. During the practice, men stimulated their partner’s clitoris for exactly 15 minutes (he received no sexual stimulation). Midway through the practice, researchers injected 18F-fluorodeoxyglucose so the scan would reflect cerebral metabolism during the practice. Positron emission tomography (PET) imaging was performed approximately 30 minutes later. Results: In the female participants, the meditation state showed significant decreases in the left inferior frontal, inferior parietal, insula, middle temporal, and orbitofrontal regions as well as in the right angular gyrus, anterior cingulate and parahippocampus compared to a neutral state (p<0.01). Male subjects had significant decreases in the left middle frontal, paracentral, precentral, and postcentral regions as well as the right middle frontal and paracentral regions during meditation (p<0.01). Men also had significantly increased metabolism in the cerebellum and right postcentral and superior temporal regions (p<0.01). Conclusions: These findings represent a distinct pattern of brain activity, for both men and women, that is a hybrid between that of other meditation practices and sexual stimulation. Such findings have potential psychotherapeutic implications and may deepen our understanding of the relationship between spiritual and sexual experience.

Neuroimaging evaluation of the long term impact of a novel paired meditation practice on brain function

“…Both OM and non-meditation subjects were excluded based on previous studies performed at our Department so that “(Luders and Kurth, 2019 ) they had any active psychological, physical, or neurological disorders that might affect cerebral metabolism (Afonso et al, 2020 ); they were taking medications that could alter cerebral blood flow or metabolism; and (Manna et al, 2010 ) they had significant claustrophobia or other reason why they could not lie still in the scanner. Female subjects were excluded if they were breastfeeding or pregnant (Newberg et al, 2023 ).”…”

“…The FDG PET imaging was performed utilizing general standard of care procedures at the Marcus Institute of Integrative Health that have been previously reported (Newberg et al, 2023 ). All subjects initially had an intravenous catheter inserted with an attached intravenous saline bag placed on a moveable pole.…”

“…After the subjects rested for approximately 10 min, 148 to 296 MBq of FDG were injected via a manual bolus. PET scans were acquired on a 3T Siemens mMR PET-MRI scanner (Siemens Medical Solutions USA, Inc., Malvern, PA) over approximately 30 min (Newberg et al, 2023 ).…”

“…The 18 F-FDG PET brain images were analyzed utilizing SPM12 (Wellcome Department of Cognitive Neurology, Institute of Neurology, London, UK) running on Matlab 2020b (MathWorks Inc., Sherborn, MA). The processing steps that were used for the analysis are provided as follows and were previously described (Newberg et al, 2023 ): “(1) Segmentation of the anatomical (T1-weighted) MRI data into gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) tissue compartments and creation of a skull-stripped version of the original anatomical scan used for PET-MRI co-registration. (2) PET-MRI co-registration: Using rigid-body transformations the spatial orientation of the PET and MRI images from the same subject were aligned.…”