The cerebral cortex is very wrinkled. how does the wrinkling make the brain more efficient?

By increasing the surface area and amount of neurons.

Explanation:

The outer layer made up of the neural tissue that covers the cerebrum of the brain is known as the cerebral cortex. The cerebral cortex is important as the integration of the signals takes place in this region.The entire surface of the cerebral cortex is covered in folds and grooves and appears wrinkled. The names used for the folds is known as gyrus whereas the grooves are known as the sulcus. These wrinkles increase the total surface area of the brain which in turn allows the accomodation of more neurons and makes the brain much mroe efficient.