Fractional Anisotropy estimates how ‘cigar-shaped’ (anisotropic) white matter fiber tracts are at a given voxel. A greater fractional anisotropy means greater white matter fiber density and/or coherence.

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- Volumetry

- Concentration

- Thickness

- Fractional Anisotropy

- Diffusivity

- Gyrification


Different Morphometric Measures 

Tang, YY., Hölzel, B. & Posner, M. The neuroscience of mindfulness meditation. Nat Rev Neurosci 16, 213–225 (2015). https://doi.org/10.1038/nrn3916.

The Neuroscience of Mindfulness Meditation

Wang, P. P., & Jernigan, T. L. (1994). Morphometric studies using neuroimaging. Neurologic clinics, 12(4), 789–802.

Morphometric studies using neuroimaging. 

Volumetry measures the volume (mm^2) of a particular region of interest (e.g. amygdala). The significance of volumetry measures is that larger volumetric measures translate to be a larger structure size of that particular brain region.

Volumetry in morphometry

Concentration estimates the concentration of gray or white matter throughout the brain on a voxel-by-voxel basis, or in voxels within a predefined region of interest. The significance of a concentration measurement in morphometry is that greater concentration means that there is a greater density of tissue type within voxel or region of interest.

Concentration in morphometry

Thickness estimates the thickness (mm) of cortex or other structures (e.g., corpus callosum). The significance of thickness in the measurement of brain structure is that greater thickness translates to a greater number of neurons/glia or fibers in a given region.

Thickness in morphometry

Fractional anisotropy in morphometry

Diffusivity estimates the coherence of water diffusion either parallel (axial diffusivity) or perpendicular (radial diffusivity) to axons. A Lower axial diffusivity means that there is greater axonal integrity. A lower radial diffusivity means that there is a greater myelination.

Diffusivity in morphometry


Gyrification estimates the degree of folding of cortical surface on a point-by-point basis. A higher index of gyrification means that there is greater cortical surface area (mm^2) per unit volume (mm^3), which is associated with greater cognitive functionality.

Gyrification in morphometry

Somatic:

- Improved Immune Response

- Improvement in Conditions Worsened by Stress

Neurological:

- Improved functioning of the amygdala and dorsal anterior cingulate cortex

- Increased gray matter in the right anterior insula

- Increased left-sided anterior activation

- Increased connection between the amygdala and the ventromedial prefrontal cortex (VMPFC)

Physical Effects Resulting From Mindfulness-Based Stress Reduction

There is preliminary evidence that results from disparate methods are comparable. Regardless of this preliminary evidence, different methods should not be expected to produce consistent results, since they likely rely on different underlying cellular changes for their outcomes. Nevertheless, the sensitivity differences of the varying morphometric imaging methods may be more of a  source of additional information than a shortcoming.




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