An investigation of brain processes supporting meditation

Abstract

Meditation is an ancient spiritual practice, which aims to still the fluctuations of the mind. We investigated meditation with fMRI in order to identify and characterise both the "neural switch" mechanism used in the voluntary shift from normal consciousness to meditation and the "threshold regulation mechanism" sustaining the meditative state. Thirty-one individuals with 1.5-25 years experience in meditation were scanned using a blocked on-off design with 45 s alternating epochs during the onset of respectively meditation and normal relaxation. Additionally, 21 subjects were scanned during 14.5 min of sustained meditation. The data were analysed with SPM and ICA. During the onset of meditation, activations were found bilaterally in the putamen and the supplementary motor cortex, while deactivations were found predominately in the right hemisphere, the precuneus, the posterior cingulum and the parieto-temporal area. During sustained meditation, SPM analysis revealed activation in the head of nucleus caudatus. Extensive deactivations were observed in white matter in the right hemisphere, i.e. mainly in the posterior occipito-parieto-temporal area and in the frontal lobes. ICA identified 38 components including known baseline-resting state components, one of which not only overlaps with the activated area revealed in the SPM analysis but extends further into frontal, temporal, parietal and limbic areas, and might presumably constitute a combination of frontoparietal and cinguloopercular task control systems. The identified component processes display varying degrees of correlation. We hypothesise that a proper characterisation of brain processes during meditation will require an operational definition of brain dynamics matching a stable state of mind.

Impact of mindfulness on the neural responses to emotional pictures in experienced and beginner meditators

“…This reduced activation in the right MPFC is consistent with findings from Baerentsen et al (2010), who reported deactivation of this cortical region during sustained meditation. Additionally, our findings are in line with a study conducted by Kross and colleagues (Kross et al, 2009) investigating the relationship between brain function and the acceptance of emotional states.…”

Operational Definition: The “Achilles Heel” of Meditation

“…Rao and Paranjpe (2008, p. 188) tried to coin the expression "passive diffused attention or inattention" when referring to meditation. Baerentsen et al (2010) refer to meditation as the control of fluctuations of the mind that aim to still the fluctuations (patterning) of the mind. These authors are naturally referring to the effects and not to the technique, and offer a confusing understanding to its readers.…”

The exploration of meditation in the neuroscience of attention and consciousness

“…The research reports on meditation in this issue (Baerentsen et al 2010;Baijal and Srinivasan 2010;Cahn et al 2010;Travis et al 2010) investigate the neural changes as the practitioners meditate in the laboratory (Tagini and Raffone's article in this issue presents a related theoretical development). These studies employ both FA and OM meditation types.…”

“…The fMRI investigation by Baerentsen et al (2010) elucidates fundamental aspects of meditation practice beyond specific styles, with a view of meditation as a practice to still the fluctuations of the mind, with reference to Patanjali's classical analysis of yoga. Baerentsen et al's study reveals distributed deactivation and activation patterns in the brain, in both cortical and subcortical regions, characterizing switching into the meditation state and sustaining it.…”