Long-term meditators show high levels of gamma waves in the brain, especially in the prefrontal cortex

Gamma waves are high frequency brain waves that are associated with active thought, learning, memory, and intelligence. In meditators, these waves show increased levels and speed of synchronization across neurons, suggesting that the brain cells are working together more efficiently. This improved neural synchronization results in more effective transmission of information. The experience for the meditator is greater mental focus and clarity.

https://www.expandinglight.org/blog/meditation/meditation-teacher-training/how-meditation-changes-your-brain/