The effects of meditation on brain function are an active area of neuroscience research. Eileen Luders, a neurologist at UCLA has recently published the results of a study in which morphological changes in a portion of the frontal lobe called the insula were seen in meditators. The changes, which involved increased amounts of in-folding of the cortex, were quantitatively related to the duration of meditation practice. This is important for several reasons. First, gyrification is seen as a key step in increasing the volume of the cerebral cortex within the confines of the rigid skull; more gyrification means more brain capacity. Second, the quantitative relationship or dose relationship implies that the change in structure is a response to the meditation. Third, a structural adaption of the brain to activity raises question as to what is going on in all that extra brain! Neural plasticity involves strengthening of synaptic connections through a process called long term potentiation, but also generation of new neurons or neurogenesis may underlie some key aspects of neural plasticity.
Current data suggest that neurogenesis occurs under physiological conditions in very restricted areas of the brain. The best studied is the granular cell zone of the dentate gurus of the hippocampus. Another less well studied area of neurogenesis is in the subventricular zone of the frontal lobe. New neurons from this area migrate a comparatively long way to the olfactory cortex in the ventral olfactory neurogenic stream (VONS) and form key interneurons involved with sense of smell. Could some new neurons also migrate to other regions of the frontal lobe neocortex?
Neocortical neurogenesis is a controversial notion. Researchers including Liz Gould of Princeton University seem to hold out the possibility at least in sufficiently supportive conditions. Others, such as Fred Gage at the Salk Institute find no evidence to support this in man through carbon 14 dating studies. What we need is a BrDU labeling study in meditators! Any volunteers?!!
The unique brain anatomy of meditation practitioners: alterations in cortical gyrification
by Lutz Jäncke, frontiersin.org
November 30th -0001
1 Laboratory of Neuro Imaging, Department of Neurology, UCLA School of Medicine, Los Angeles, CA, USA
2 Department of Medicine, Center for Neurobiology of Stress, UCLA School of Medicine, Los Angeles, CA, USA
3 Department of Psychiatry, University of Jena, Jena, Germany
4 Department of Neurology, University of Jena, Jena, Germany
Several cortical regions are reported to vary in meditation practitioners. However, prior analyses have focused primarily on examining gray matter or cortical thickness. Thus, additional effects with respect to other cortical features might have remained undetected. Gyrification (the pattern and degree of cortical folding) is an important cerebral characteristic related to the geometry of the brain’s surface. Thus, exploring cortical gyrification in long-term meditators may provide additional clues with respect to the underlying anatomical correlates of meditation. This study examined cortical gyrification in a large sample (n = 100) of meditators and controls, carefully matched for sex and age. Cortical gyrification was established by calculating mean curvature across thousands of vertices on individual cortical surface models. Pronounced group differences indicating larger gyrification in meditators were evident within the left precentral gyrus, right fusiform gyrus, right cuneus, as well as left and right anterior dorsal insula (the latter representing the global significance maximum). Positive correlations between gyrification and the number of meditation years were similarly pronounced in the right anterior dorsal insula. Although the exact functional implications of larger cortical gyrification remain to be established, these findings suggest the insula to be a key structure involved in aspects of meditation. For example, variations in insular complexity could affect the regulation of well-known distractions in the process of meditation, such as daydreaming, mind-wandering, and projections into past or future. Moreover, given that meditators are masters in introspection, awareness, and emotional control, increased insular gyrification may reflect an integration of autonomic, affective, and cognitive processes. Due to the cross-sectional nature of this study, further research is necessary to determine the relative contribution of nature and nurture to links between cortical gyrification and meditation.
Keywords: brain, cortical complexity, curvature, folding, insula, meditation, mindfulness, MRI
Citation: Luders E, Kurth F, Mayer EA, Toga AW, Narr KL and Gaser C (2012) The unique brain anatomy of meditation practitioners: alterations in cortical gyrification. Front. Hum. Neurosci. 6:34. doi: 10.3389/fnhum.2012.00034
Received: 09 November 2011; Accepted: 14 February 2012; Published online: 29 February 2012.
Amishi P. Jha, University of Miami, USA
, University of Zurich, Switzerland
Donna R. Roberts, Medical University of South Carolina, USA
Copyright: © 2012 Luders, Kurth, Mayer, Toga, Narr and Gaser. This is an open-access article distributed under the terms of the Creative Commons Attribution Non Commercial License, which permits non-commercial use, distribution, and reproduction in other forums, provided the original authors and source are credited.
*Correspondence: Eileen Luders and Arthur W. Toga, Laboratory of Neuro Imaging, Department of Neurology, UCLA School of Medicine, 635 Charles Young Drive South, Suite 225, Los Angeles, CA 90095-7334, USA. e-mail: email@example.com; firstname.lastname@example.org