Research on brain networks shows that the brain is organized into interacting systems rather than isolated regions. Networks are groups of brain areas that show coordinated activity and jointly support particular functions, such as perception, memory, or attention.

One key finding is the existence of large-scale networks like the default mode network, which is active when we are inwardly focused, the frontoparietal control network, which helps with flexible decision making, and sensory networks that process vision, hearing, and movement. These networks can be identified using functional MRI by tracking correlations in activity over time.

The brain’s wiring is studied as a connectome, mapping structural links between regions and functional relationships in their activity patterns. Graph theory provides tools to describe this organization, treating brain regions as nodes and connections as edges. Measures such as degree, modularity, and path length characterize how efficiently information flows and how networks are clustered into communities.

Network development is not fixed at birth. During childhood and adolescence, connections are refined, long range links strengthen, and network segregation and integration increase. Aging is linked to reduced segregation between networks and changes in connectivity that may affect cognition.

Clinical research links altered network organization to neurological and psychiatric conditions. Disorders such as schizophrenia, depression, Alzheimer’s disease, and epilepsy show characteristic disruptions in connectivity patterns. These changes may contribute to symptoms and could serve as biomarkers or targets for interventions.

Overall, the network perspective reveals that brain function emerges from dynamic interactions between distributed systems, highlighting integration, flexibility, and balance between specialized and global processing.