Bridging the hemispheres in meditation: thicker callosal regions and enhanced fractional anisotropy (FA) in long-term practitioners.
Eileen Luders, Owen R Phillips, Kristi Clark, Florian Kurth, Arthur W Toga, Katherine L Narr
Neuroimage February 21, 2012 DOI: 10.1016/j.neuroimage.2012.02.026 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Cross-sectional observational study Longitudinal Peer reviewed |
|---|---|
| Sample size | 60 |
| Population | 30 long-term meditators and 30 controls matched for sex, age, and handedness |
| Intervention | Meditation |
| Measures | fractional anisotropy (FA), callosal thickness |
| Topics | Meditation |
| Keywords | Corpus callosum Humans Magnetic resonance imaging Anisotropy Image processing, computer-assisted Middle aged Female Functional laterality Young adult Diffusion tensor imaging |
| Key findings | Callosal measures were larger in long-term meditators than controls, particularly in anterior sections, but differences reached significance only with point-wise rather than segment-specific measures and were more prominent for fractional anisotropy than callosal thickness. The authors propose these findings may indicate greater connectivity and hemispheric integration, while cautioning that behavioral confirmation and longitudinal studies are needed. |
Abstract
Recent findings suggest a close link between long-term meditation practices and the structure of the corpus callosum. Prior analyses, however, have focused on estimating mean fractional anisotropy (FA) within two large pre-defined callosal tracts only. Additional effects might exist in other, non-explored callosal regions and/or with respect to callosal attributes not captured by estimates of FA. To further explore callosal features in the framework of meditation, we analyzed 30 meditators and 30 controls, carefully matched for sex, age, and handedness. We applied a multimodal imaging approach using diffusion tensor imaging (DTI) in combination with structural magnetic resonance imaging (MRI). Callosal measures of tract-specific FA were complemented with other global (segment-specific) estimates as well as extremely local (point-wise) measures of callosal micro- and macro-structure. Callosal measures were larger in long-term meditators compared to controls, particularly in anterior callosal sections. However, differences achieved significance only when increasing the regional sensitivity of the measurement (i.e., using point-wise measures versus segment-specific measures) and were more prominent for microscopic than macroscopic characteristics (i.e., callosal FA versus callosal thickness). Thicker callosal regions and enhanced FA in meditators might indicate greater connectivity, possibly reflecting increased hemispheric integration during cerebral processes involving (pre)frontal regions. Such a brain organization might be linked to achieving characteristic mental states and skills as associated with meditation, though this hypothesis requires behavioral confirmation. Moreover, longitudinal studies are required to address whether the observed callosal effects are induced by meditation or constitute an innate prerequisite for the start or successful continuation of meditation.
Comparable studies
Other cross-sectional and survey studies on meditation, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Construct Validity of the Five Facet Mindfulness Questionnaire in Meditating and Nonmeditating Samples Experienced meditators and nonmeditating comparison groups | 2008 | Cross-sectional study | |
| Neural Correlates of Dispositional Mindfulness During Affect Labeling Adult participants | 2007 | Observational cross-sectional | n = 27 |
| Assessing mindfulness in children and adolescents: Development and validation of the Child and Adolescent Mindfulness Measure (CAMM). School-aged children and adolescents | 2011 | Cross-sectional validation study | n = 1,413 |
| Mindfulness and self-compassion as predictors of psychological wellbeing in long-term meditators and matched nonmeditators Experienced meditators and demographically matched nonmeditators | 2012 | Cross-sectional study | n = 152 |
| Mechanisms of Action in the Inverse Relationship Between Mindfulness and Psychological Distress Undergraduates | 2008 | Cross-sectional, correlational |
Citations in the library
Cited by 37
- Breath of Life: The Respiratory Vagal Stimulation Model of Contemplative Activity Frontiers in Human Neuroscience October 9, 2018
- Meditation effects within the hippocampal complex revealed by voxel-based morphometry and cytoarchitectonic probabilistic mapping Frontiers in Psychology 2013
- Issues and Perspectives in Meditation Research: In Search for a Definition Frontiers in Psychology 2013
- Meditation reduces pain-related neural activity in the anterior cingulate cortex, insula, secondary somatosensory cortex, and thalamus Frontiers in Psychology December 16, 2014
- Epistemological implications of near-death experiences and other non-ordinary mental expressions: Moving beyond the concept of altered state of consciousness Medical Hypotheses April 11, 2015
and 32 more in the library
Cites 21
- Alterations in Brain and Immune Function Produced by Mindfulness Meditation Psychosomatic Medicine July 1, 2003
- Meditation experience is associated with increased cortical thickness Neuroreport November 7, 2005
- Long-term meditators self-induce high-amplitude gamma synchrony during mental practice Proceedings of the National Academy of Sciences November 8, 2004
- Neural correlates of attentional expertise in long-term meditation practitioners Proceedings of the National Academy of Sciences June 28, 2007
- Neural Correlates of Dispositional Mindfulness During Affect Labeling Psychosomatic Medicine July 1, 2007
and 16 more in the library