White matter matters
Quantifying the living human brain isn’t an easy task, particularly when it comes to elusive and difficult to measure high cognitive functions such as behavior, empathy, humanity, and humility. (Yes, I am referring to Meghan Markle). Recently, scientists used diffusion tensor imaging (DTI) to examine how individual differences in behavior might compare to white matter structure and connectivity.
White matter is the tissue through which messages pass between different areas of grey matter within the brain.
A team of researchers from China came to an intriguing conclusion and published the findings in the International Journal of Neuroscience. The team matched 19 young males (median age of 18 years old) who scored high on the Pathological Narcissism Inventory (PNI) test, with similar age young males scoring low.
The PNI is a self-reported test to measure dimensions of pathological narcissism. You can access and test (link) your narcissistic score on a scale of 1 to 40 to determine whether or not you score high on Entitlement Rage, Exploitativeness, Grandiose Fantasy, Self-sacrificing, Self-enhancement, and Contingent Self-esteem Hiding the Self Devaluing.
Researchers found that the integrity of white matter microstructure in the corpus callosum (CC) — the most prominent white matter structure in the human brain that connects the right and left hemispheres — appears to predict PNI score. Individuals scoring high on PNI have decreased brain white matter microstructures and connection pathways of white matter.
The abnormal white matter brain regions may be one of the neuropathological basis of narcissism.
The connections of white matter develop early in life. The first three years of a newborn’s brain’s life go through increased myelination and axonal packing. This timeframe encourages rapid microstructural white matter development of an infant. By the age of 25, normative brain development is almost complete. White matter development is fast in the first two years and progresses more slowly to as late as 30 years in humans. How the process will go on is presumably defined at birth; however, specific training may interfere with the process. Newborns can not speak, but the neural basis for…