White matter and cognition: making the connection

Summary & key facts

This paper is a review that argues the brain's white matter — the long-range wiring that connects different brain areas — is just as important for thinking as the brain's gray matter. The authors summarize evidence that white matter makes up about half the brain, that damage to white matter often causes thinking problems, and that white matter changes may be involved in diseases like Alzheimer's and chronic traumatic encephalopathy. Studying white matter more closely could help explain why people lose thinking skills and point to ways to prevent or treat those problems.

Key facts:

• White matter is the brain's wiring that connects different brain regions and helps organize behavior.
• About half of the human brain is white matter, not just gray matter.
• Across evolution, white matter has grown more than gray matter, suggesting its importance for human thinking.
• Damage to white matter (called white matter lesions) regularly leads to problems with thinking and behavior.
• The authors propose that problems with white matter may play a role in neurodegenerative diseases such as Alzheimer's disease and in chronic traumatic encephalopathy, a brain condition linked to repeated head injury.
• The review says that learning more about white matter could improve how we prevent and treat cognitive problems tied to white matter disorders.

Abstract

Whereas the cerebral cortex has long been regarded by neuroscientists as the major locus of cognitive function, the white matter of the brain is increasingly recognized as equally critical for cognition. White matter comprises half of the brain, has expanded more than gray matter in evolution, and forms an indispensable component of distributed neural networks that subserve neurobehavioral operations. White matter tracts mediate the essential connectivity by which human behavior is organized, working in concert with gray matter to enable the extraordinary repertoire of human cognitive capacities. In this review, we present evidence from behavioral neurology that white matter lesions regularly disturb cognition, consider the role of white matter in the physiology of distributed neural networks, develop the hypothesis that white matter dysfunction is relevant to neurodegenerative disorders, including Alzheimer's disease and the newly described entity chronic traumatic encephalopathy, and discuss emerging concepts regarding the prevention and treatment of cognitive dysfunction associated with white matter disorders. Investigation of the role of white matter in cognition has yielded many valuable insights and promises to expand understanding of normal brain structure and function, improve the treatment of many neurobehavioral disorders, and disclose new opportunities for research on many challenging problems facing medicine and society.

Topics

Alzheimer's disease research and treatments Functional Brain Connectivity Studies S100 Proteins and Annexins

Categories

Health Sciences Medicine Physiology

Tags

Behavioral neurology Brain Structure and Function Chronic traumatic encephalopathy Cognition Cognitive psychology Cognitive science Concussion Dementia Disease Environmental health Injury prevention Magnetic resonance imaging Medicine Neurology Neuroscience Pathology Poison control Psychology Radiology White matter

Conditions & symptoms

Difficulty focusing