Changes in functional magnetic resonance imaging with Yogic meditation: A pilot study

Abstract

Background:The neural substrates of Yogic meditation are not well understood. Meditation is theorized to be a conscious mental process that induces a set of complex physiological changes within the areas of the brain termed as the “relaxation response.”Aims and objective:Pilot data of a functional magnetic resonance imaging (fMRI) study is presented to observe and understand the selective activations of designated brain regions during meditation.Material and methods:Four trained healthy Patanjali Yoga practitioners in their mid-60s participated in this prototype interventional study. A three-part 1-min block design alternating between meditation (test) and relaxation (control) phase with an imaginary visual fixation and auditory stimulation was used.Result and observation:The fMRI images revealed strong activation in the right prefrontal regions during the visual and auditory fixation meditation phases compared to no activations during the relaxation phase. A comparison between the visual and auditory fixations revealed shifts within the prefrontal and temporal regions. In addition, activation in occipital and temporal regions was observed during the meditation phase. Occipital lobe activation was more apparent during visual meditation phase.Conclusion:It is concluded that specific fMRI brain activations are observed during different forms of Yogic meditation (visual and auditory phases). Occipital and prefrontal activation could be modulating the known neurophysiological and biological effects of meditation.

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

“…(B) Neuronal resting-state function: red ( Herzog et al, 1991 ), blue ( Khalsa et al, 2009 ), not in this figure ( Lou et al, 1999 ; Cohen et al, 2009 ; Wang et al, 2011 ). (C) Neural activation: red ( Engström et al, 2010 ), purple ( Kalyani et al, 2011 ), green ( Froeliger et al, 2012c ), pink ( Hernández et al, 2015 ), orange ( Mishra et al, 2017 ), yellow ( Wadden et al, 2018 ), dark blue ( Gothe et al, 2018 ), and light blue ( Lin et al, 2015 ). (D) Functional connectivity, seed regions (circles with a white border) connected (full lines) with brain regions (circles), representing higher functional connectivity: red ( Gard et al, 2015 ); higher degree centrality for caudate nuclei, blue ( Hernández et al, 2018 ), green ( Sevinc et al, 2018 ), pink ( Eyre et al, 2016 ), purple ( Santaella et al, 2019 ), light blue represents a network with a change in power spectrum ( Dodich et al, 2019 ), not in this figure ( Froeliger et al, 2012a ).…”

“…Fourthly, in parallel with the findings of Hernández et al (2015) , increased activation in the right prefrontal regions during a meditation phase (auditory fixation and visual fixation) was observed in four experienced Patanjali yoga practitioners. The authors did not report any statistics, detailed demographics, or scan acquisition parameters ( Mishra et al, 2017 ).…”

“…From the five studies focusing on CBF/perfusion and glucose metabolism changes during a yoga meditation practice, it was shown that CBF is influenced by yoga meditation ( Herzog et al, 1991 ; Lou et al, 1999 ; Cohen et al, 2009 ; Khalsa et al, 2009 ; Wang et al, 2011 ), but influences on CBF may depend heavily on the type and focus of the meditation ( Fox et al, 2016 ; Figure 1B ). Eight studies investigated neural activation changes during yoga meditation, with a majority of the studies showing increased activation in the frontal regions during yoga meditation ( Froeliger et al, 2012c ; Hernández et al, 2015 ; Lin et al, 2017 ; Mishra et al, 2017 ). Functional connectivity studies ( Froeliger et al, 2012a ; Gard et al, 2015 ; Eyre et al, 2016 ; Hernández et al, 2018 ; Sevinc et al, 2018 ; Dodich et al, 2019 ; Santaella et al, 2019 ) observed improved connectivity in yoga subjects, compared to controls, in multiple networks and regions.…”

“…Increased GABA levels, associated with stress reduction, decreased MI, and increased NAA levels have been reported after yoga ( Streeter et al, 2007 , 2010 ; Nagothu et al, 2015 ). Increased GABA levels might be the result of the activated PFC during or after yoga, as observed in multiple yoga studies ( Froeliger et al, 2012c ; Hernández et al, 2015 ; Lin et al, 2017 ; Mishra et al, 2017 ), which is believed to increase glutamate, stimulating the reticular nucleus of the thalamus to increase secretions of GABA ( Guglietti et al, 2013 ).…”

Virtual Reality–Guided Meditation for Chronic Pain in Patients With Cancer: Exploratory Analysis of Electroencephalograph Activity

“…Subjective reports of the benefits of mindfulness meditation have prompted investigations into the potential corresponding neurophysiological states. Exploration of fluctuations in brain wave voltage amplitude (power) topography and coherence (associated areas of activity) using EEG variations in neural activity assessed with functional magnetic resonance imaging and cortical evoked responses to visual and auditory stimuli that reflect the impact of meditation on attention [4,[17][18][19][20][21][22][23][24][25][26]. However, findings remain speculative.…”