What Has Neuroimaging Taught Us on the Neurobiology of Yoga? A Review

Abstract

Yoga is becoming increasingly popular worldwide, with several implicated physical and mental benefits. Here we provide a comprehensive and critical review of the research generated from the existing neuroimaging literature in studies of yoga practitioners. We reviewed 34 international peer-reviewed neuroimaging studies of yoga using magnetic resonance imaging (MRI), positron emission tomography (PET), or single-photon emission computed tomography (SPECT): 11 morphological and 26 functional studies, including three studies that were classified as both morphological and functional. Consistent findings include increased gray matter volume in the insula and hippocampus, increased activation of prefrontal cortical regions, and functional connectivity changes mainly within the default mode network. There is quite some variability in the neuroimaging findings that partially reflects different yoga styles and approaches, as well as sample size limitations. Direct comparator groups such as physical activity are scarcely used so far. Finally, hypotheses on the underlying neurobiology derived from the imaging findings are discussed in the light of the potential beneficial effects of yoga.

Effects of Mind‐Body Exercise in Cancer Survivors: A Systematic Review and Meta‐Analysis

“…However, Tai Chi and Qigong have their origins as martial arts based on traditional Chinese medicine, which rooted in the ancient philosophy of naive materialism and natural dialectics [ 34 ]. Yoga is a physical, mental, and spiritual discipline originating from ancient India, which could deliver practitioners from suffering or disease [ 35 ]. Different types of mind-body exercises are different in training methods and essentials, postures, movement characteristics, purpose, and function [ 36 ].…”

Management of post-traumatic stress disorder symptoms by yoga: an overview

“…In a recent review, van Aalst et al [44] synthesized neurobiology advances determined from a neuroimaging framework. First, the authors stated that despite heterogeneous practice of yoga and target assessment, cerebral structural and functional changes were consistent in the 34 included studies.…”

Twelve-Week Yoga vs. Aerobic Cycling Initiation in Sedentary Healthy Subjects: A Behavioral and Multiparametric Interventional PET/MR Study

“…First, the group size in this academic interventional trial was relatively small and the duration and frequency of the intervention was limited, because the feasibility of the study for the subjects was considered. However, previous studies investigating effects of yoga on the brain used similar study designs in terms of study duration and frequency (4,66,67,(73)(74)(75). The study length and frequency were considered as an optimal balance between study feasibility, duration, cost, and potential drop-out rate.…”

“…Besides behavioral studies, a limited number of imaging studies have investigated the effects of yoga on objective biomarkers in the brain. Different advanced neuroimaging techniques such as positron emission tomography (PET) and magnetic resonance (MR) imaging allow to investigate the biochemical, functional, and structural effects of yoga in a non-invasive way ( 4 ). However, since most studies so far have focused specifically on the meditational dimension of yoga, evidence for the combined tripartite effects is scarce.…”

“…As the choice of an appropriate control group is critical to disentangle the impact of yoga practice on brain function without confounding factors ( 4 , 18 ), we have chosen to use moderate-intensity indoor cycling as control intervention. Both interventions are practiced in group, can be guided by a skilled teacher, are of similar duration per exercise unit and can be metabolically matched.…”