White matter integrity refers to the structural and functional health of the white matter in the brain. White matter consists of nerve fibers covered in myelin, which transmit signals between different regions of the brain. Disruption or damage to white matter can impair communication between brain regions and lead to a variety of cognitive and neurological conditions, such as multiple sclerosis, Alzheimer's disease, and traumatic brain injury. Research in this area aims to understand the factors that contribute to white matter integrity, how it changes over time, and how it may be improved or protected through interventions such as exercise, cognitive training, or medication. Techniques such as diffusion tensor imaging and magnetic resonance imaging are commonly used to study white matter integrity.