Cool article that I recently came across.
'India's Vedic Sanskrit pandits train for years to orally memorize and exactly recite 3,000-year old oral texts ranging from 40,000 to over 100,000 words. We wanted to find out how such intense verbal memory training affects the physical structure of their brains. Through the India-Trento Partnership for Advanced Research (ITPAR), we recruited professional Vedic pandits from several government-sponsored schools in the Delhi region; then we used structural magnetic resonance imaging (MRI) at India’s National Brain Research Center to scan the brains of pandits and controls matched for age, gender, handedness, eye-dominance and multilingualism.
What we discovered from the structural MRI scanning was remarkable. Numerous regions in the brains of the pandits were dramatically larger than those of controls, with over 10 percent more grey matter across both cerebral hemispheres, and substantial increases in cortical thickness. Although the exact cellular underpinnings of gray matter and cortical thickness measures are still under investigation, increases in these metrics consistently correlate with enhanced cognitive function.
Most interestingly for verbal memory was that the pandits' right hippocampus—a region of the brain that plays a vital role in both short and long-term memory—had more gray matter than controls across nearly 75 percent of this subcortical structure. Our brains have two hippocampi, one on the left and one on the right, and without them we cannot record any new information. Many memory functions are shared by the two hippocampi. The right is, however, more specialized for patterns, whether sound, spatial or visual, so the large gray matter increases we found in the pandits’ right hippocampus made sense: accurate recitation requires highly precise sound pattern encoding and reproduction. The pandits also showed substantially thickening of right temporal cortex regions that are associated with speech prosody and voice identity.'