Meditation and neurodegeneration; what do we know?

Can meditation stop or reverse neurodegeneration? The answer is yes but the method can’t resolve any problems by itself.

meditatebandw

Authors: Newberg, A. B., Serruya, M., Wintering, N., Moss, A. S., Reibel, D., & Monti, D. A.

Year: 2014

Title: Meditation and neurodegenerative diseases.

Summary: Meditation research is now so fragmented that only by taking an overview can a fuller understanding of what we know be arrived at. In the research literature, these overviews are called strategic reviews or meta-studies. Newberg and colleagues offer their perspective on what we know about how our brain functions decline and what we can do to stop it. The authors set out the broad definitions for Alzheimer’s Disease, Frontotemporal lobar dementia (FTLD) including Pick’s Disease and Parkinson’s Disease, and discuss the potential of meditation to help people with declining brain function.

There is no shortage of evidence for a relationship between meditation and both functional and structural change in the brain, but the devil really is in the detail. In common with a wide range of other behaviours, meditation will have an effect on the brain, but understanding which meditation methods create which effects is not a simple matter. This meta-study describes the influence of meditation into two areas, attention and memory, but it also includes an element of cognition more generally. The paper illustrates evidence for a relationship between meditation and improvements in performance in all three areas (attention, memory and other cognitive functions). Some of these improvements have been linked to recorded physical changes to the brain. Individual studies are discussed demonstrating quite specific effects of meditation practices. For example that vipassana meditation appears to improve working memory and focused attention methods may help sustained visual attention.

Unfortunately, there is almost no replication of the cited effects (replication being identical studies reporting the same results). This report also reduces all meditation to a singular family of mind training, evidence suggests that this is an unscientific approach. Grouping together methods from kundalini, tantra, sutra with MBIs in a meta-review is fraught with difficulty, particularly as robust theoretical frameworks for these practices don’t exist in neuroscience or cognitive psychology. However, in defence of the authors, meditation has been researched in the west for at least 45 years and attempts to understand and review progress should be welcomed.

Link: https://nyaspubs.onlinelibrary.wiley.com

Meditation can change the size of your brain

The brain is plastic, to what extend does it undergo structural changes during meditation?

pexels-photo-935553.jpeg

Authors: Kieran C.R. Fox, Savannah Nijeboer, Matthew L. Dixon, James L. Floman,
Melissa Ellamil, Samuel P. Rumak, Peter Sedlmeier, Kalina Christoff

Year: 2014

Title: Is meditation associated with altered brain structure? A systematic review and meta-analysis of morphometric neuroimaging in meditation practitioners

Summary: Like almost every contemplative scientist will point out, our understanding of what meditation can do for us in its infancy. However, this investigation sets out the progress made in understanding meditation related to structural changes in the brain. The researcher identified 21 studies that imaged the brains of meditators, looking for structural changes. Although most of the research was cross-sectional in nature some ‘before and after’ examples are included.

This project reviewed research that used any of the six leading measures of structural changes in the brain (volumetry, concentration, thickness, fractional anisotropy (FA), diffusivity (axial and radial) and gyrification). The selected papers were qualitatively reviewed and also subject to an anatomical likelihood estimation (ALE) meta-analysis. Qualitative results highlighted nine brain areas that might have undergone structural alteration as a result of meditation practice. Seven areas of grey matter: anterior/mid-cingulate cortex, fusiform gyrus, hippocampus, inferior temporal gyrus, insular cortex, rostrolateral prefrontal cortex, somatomotor cortices and two white matter pathways: corpus callosum, superior longitudinal fasciculus.

Although Lazer et al. made efforts to link the results of morphometric neuroimaging to a range of functional studies there are a number of problems in this approach. There is little structure in how meditators and meditation methods are grouped together,  both in creating the meta-analysis and explanations for alterations in brain structures. This in part reflects the limitations of the 21 neuroimaging studies used, it is also linked to the widely documented problems in the theoretical frameworks used by contemplative science. For example, common features are looked for in diverse experiments using different forms of meditation, both secular and spiritual. Although the participants from the experimental groups cited in the studies had all meditated, they often differ significantly in the methods they use, frequency and duration of practice and time spent in intensive meditation retreat.

Despite the limitations, which are in large part symptomatic of meditation research in general, this remains an influential study fo0r both cognitive psychology and neuroscience.

Link: https://www.sciencedirect.com