Neurochemical dynamics during two hypnotic states evidenced by magnetic resonance spectroscopy

This study explores neurochemical changes in the brain during hypnosis, targeting the parieto-occipital (PO) and posterior superior temporal gyrus (pSTG) regions using proton magnetic resonance spectroscopy (MRS). We examined 52 healthy, hypnosis experienced participants to investigate how two different hypnotic states of varying depth impacted brain neurochemistry in comparison to each other and to their respective non-hypnagogic control conditions. Alongside neurochemical assessments, we recorded respiration and heart rate variability (HRV) to further explore possible associations between physiological correlates of hypnotic depth. Significant changes in myo-Inositol concentration relative to total creatine were observed in the PO region during the deeper hypnosis state, possibly indicating reduced neuronal activity. No significant neurochemical shifts were detected in the pSTG region. Additionally, our findings revealed notable physiological changes during hypnosis. Respiratory rates were significantly slowed in both hypnotic states compared to the respective controls, with more pronounced slowing in the deeper hypnotic state. This study contributes a first-time insight into neurochemical responses during hypnotic states. We hope offering a foundation for further research in understanding the neurobiological correlates of hypnosis in both, basic science and—down the line—clinical applications.