Whether functional brain networks in Alzheimer's Disease(AD) are characterized by a loss of small-world features

Cognitive dysfunction in Alzheimer's disease(AD) could be due, at least in part, to a functional disconnection between distant brain areas. Correlation between signals of brain activity reflects functional interactions between different brain areas. An approach to the characterization of a network as complex as human brain is to apply graph theory. Graphs with many local connections and a few random long distance connections are characterized by a high cluster coefficient and a short path length; such near-optimal networks are designated as ‘‘small-world’’ networks.