title: Shifting brain asymmetry: the link between meditation and structural lateralization.
abstract: Previous studies have revealed an increased fractional anisotropy and greater thickness in the anterior parts of the corpus callosum in meditation practitioners compared with control subjects. Altered callosal features may be associated with an altered inter-hemispheric integration and the degree of brain asymmetry may also be shifted in meditation practitioners. Therefore, we investigated differences in gray matter asymmetry as well as correlations between gray matter asymmetry and years of meditation practice in 50 long-term meditators and 50 controls. We detected a decreased rightward asymmetry in the precuneus in meditators compared with controls. In addition, we observed that a stronger leftward asymmetry near the posterior intraparietal sulcus was positively associated with the number of meditation practice years. In a further exploratory analysis, we observed that a stronger rightward asymmetry in the pregenual cingulate cortex was negatively associated with the number of practice years. The group difference within the precuneus, as well as the positive correlations with meditation years in the pregenual cingulate cortex, suggests an adaptation of the default mode network in meditators. The positive correlation between meditation practice years and asymmetry near the posterior intraparietal sulcus may suggest that meditation is accompanied by changes in attention processing.
authors.affiliation: Department of Neurology, UCLA School of Medicine, Los Angeles, CA 90095-7334, USA and Laboratory of Neuro Imaging, USC School of Medicine, Los Angeles, CA 90032, USA.
authors.forename: Florian
authors.initials: F
authors.lastname: Kurth
authors.affiliation: Department of Neurology, UCLA School of Medicine, Los Angeles, CA 90095-7334, USA and Laboratory of Neuro Imaging, USC School of Medicine, Los Angeles, CA 90032, USA.
authors.forename: Allan
authors.initials: A
authors.lastname: MacKenzie-Graham
authors.affiliation: Department of Neurology, UCLA School of Medicine, Los Angeles, CA 90095-7334, USA and Laboratory of Neuro Imaging, USC School of Medicine, Los Angeles, CA 90032, USA.
authors.forename: Arthur W
authors.initials: AW
authors.lastname: Toga
authors.affiliation: Department of Neurology, UCLA School of Medicine, Los Angeles, CA 90095-7334, USA and Laboratory of Neuro Imaging, USC School of Medicine, Los Angeles, CA 90032, USA eileen.luders@ucla.edu.
authors.forename: Eileen
authors.initials: E
authors.lastname: Luders
mesh_terms: D000328:Adult; D000368:Aged; D016880:Anisotropy; D001288:Attention / Q000502:physiology; D001931:Brain Mapping; D003337:Corpus Callosum / Q000033:anatomy & histology / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D066128:Gray Matter / Q000033:anatomy & histology / Q000502:physiology; D006179:Gyrus Cinguli / Q000033:anatomy & histology / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D019122:Meditation; D008875:Middle Aged; D064866:Mindfulness; D010296:Parietal Lobe / Q000033:anatomy & histology / Q000502:physiology; D055815:Young Adult
keywords: MRI; VBM; attention; default mode network; gray matter; mindfulness