Here is a saying in science, "Correlation does not indicate causation."

You perceived improvement in cognitive function may have nothing to do with your anger explosion. Or, it could be that your brain hormones and such surged. Your combat sports may have conditioned your brain to release endorphins that can heighten mental function when you get stimulated by physical activity. Nobody can say.

By brain chemistry, I am referring to any of the chemical functions in the brain and how they cause toxic residue. Every metabolic function has its waste products. Repeated or high intensity stresses can overwhelm the brains toxin elimination system and cause brain dysfunction.

It is similar when one works out at the gym or goes for a hard run, the intense muscle use causes lactic acid to build up. The lactic acid clears from the muscles with just moderate muscle use.

The toxins in the brain only clear during a specific stage of sleep. If you are not experiencing enough slow wave sleep for the amount of waste produced, the brain can remain polluted. It struggles to use nutrients when it is congested with waste products. This is not a damaged condition.

Stress, physical or emotional stress, increases the production of these waste products that need to be cleared.