Sunday, March 11, 2012

More on the Neuroscience of Meditation


Frontiers in Human Neuroscience recently published two new studies looking at the brain changes associated with meditation. These are open access publications, so the PDFs can be downloaded from the site. Both of these studies demonstrate that the brains of meditators are more integrated than those who do not meditate.

Observed benefits:
  • 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
  • increased insular gyrification may reflect an integration of autonomic, affective, and cognitive processes
  • Participants with more meditation experience exhibited increased connectivity within attentional networks, as well as between attentional regions and medial frontal regions
  • These neural relationships may be involved in the development of cognitive skills, such as maintaining attention and disengaging from distraction, that are often reported with meditation practice
Enjoy.

The unique brain anatomy of meditation practitioners: alterations in cortical gyrification

  • 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.


Citation: Luders E, Kurth F, Mayer EA, Toga AW, Narr KL, and Gaser C. (2012, Feb 29). The unique brain anatomy of meditation practitioners: alterations in cortical gyrification. Frontiers in Human Neuroscience, 6:34. doi: 10.3389/fnhum.2012.00034

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Effects of meditation experience on functional connectivity of distributed brain networks

  • Department of Psychology, Emory University, Atlanta, GA, USA
This study sought to examine the effect of meditation experience on brain networks underlying cognitive actions employed during contemplative practice. In a previous study, we proposed a basic model of naturalistic cognitive fluctuations that occur during the practice of focused attention meditation. This model specifies four intervals in a cognitive cycle: mind wandering (MW), awareness of MW, shifting of attention, and sustained attention. Using subjective input from experienced practitioners during meditation, we identified activity in salience network regions during awareness of MW and executive network regions during shifting and sustained attention. Brain regions associated with the default mode were active during MW. In the present study, we reasoned that repeated activation of attentional brain networks over years of practice may induce lasting functional connectivity changes within relevant circuits. To investigate this possibility, we created seeds representing the networks that were active during the four phases of the earlier study, and examined functional connectivity during the resting state in the same participants. Connectivity maps were then contrasted between participants with high vs. low meditation experience. Participants with more meditation experience exhibited increased connectivity within attentional networks, as well as between attentional regions and medial frontal regions. These neural relationships may be involved in the development of cognitive skills, such as maintaining attention and disengaging from distraction, that are often reported with meditation practice. Furthermore, because altered connectivity of brain regions in experienced meditators was observed in a non-meditative (resting) state, this may represent a transference of cognitive abilities “off the cushion” into daily life.
Citation: Hasenkamp W, and Barsalou LW. (2012, Mar 1). Effects of meditation experience on functional connectivity of distributed brain networks. Frontiers in Human Neuroscience, 6:38. doi: 10.3389/fnhum.2012.00038
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