ISLAMABAD: The abundance of crevices and ridges in the outer layer of the human brain – commonly referred to as “folds” – make the organ instantly recognizable. Theory holds that the folding brain is a result of evolution, a way to condense the cerebral cortex and improve brain cell communication and functioning. Now, researchers have shed light on how folding occurs in the human brain and how it changes with age.To find out whether folding of the cerebral cortex is universal in humans, Dr. Wang and team used magnetic resonance imaging (MRI) to map the brain folds of more than 1,000 healthy adults. However, the team found that as we age, cortical folding changes. Specifically, the researchers found that tension on the inside of the cerebral cortex reduces. “It would be similar to the skin,” explains Dr. Wang. “As we age, the tension drops and the skin starts to slacken.” The researchers also identified gender differences in cortical folding; among men and women of the same age, the cerebral cortex of women showed slightly less folding. “More work is needed in this area but it does suggest that the effect Alzheimer’s disease has on the folding of the brain is akin to premature aging of the cortex,” says Dr. Wang. “The next step will be to see if there is a way to use the changes in folding as an early indicator of disease.” Overall, the researchers believe their study has provided some much-needed insight into the factors that influence cortical folding in the human brain. Dr. Yujiang Wang said that “It has long been known that the size and thickness of the cortex changes with age but the existence of a general law for folding shows us how to combine these quantities into a single measure of folding that can then be compared between genders, age groups, and disease states.”