Activity lingers longer in certain areas of the brain in those with Alzheimer's than it does in healthy people, Mayo Clinic researchers who created a map of the brain found. The results suggest varying brain activity may reduce the risk of Alzheimer's disease. The study, "Non-stationarity in the "Resting Brain's" Modular Architecture," was presented at the Alzheimer's Association International Conference and recently published in the journal PLoS One. Researchers compared brain activity to a complex network, with multiple objects sharing information along pathways.

"Our understanding of those objects and pathways is limited," says lead author David T. Jones, M.D. "There are regions in the brain that correspond to those objects, and we are not really clear exactly what those are. We need a good mapping or atlas¹（地图集） of those regions that make up the network in the brain, which is part of what we were doing in this study."

Researchers examined 892 cognitively² normal people taking part in the Mayo Clinic Study of Aging, and set out to create an active map of their brains while the people were "at rest," not engaged in a specific task. To do this, they employed task-free, functional³ magnetic resonance⁴ imaging to construct an atlas of 68 functional regions of the brain, which correspond to the cities on the road map.

Researchers filled in the roads between these regions by creating dynamic（动态的） graphic⁵ representations of brain connectivity within a sliding time window.

This analysis revealed that there were many roads that could be used to exchange information in the brain, and the brain uses different roads at different times. The question to answer then, said Dr. Jones, is whether or not Alzheimer's patients used this map and these roads in a different way than their healthy peers.

"What we found in this study was that Alzheimer's patients tended to spend more time using some roads and less time using other roads, biasing⁶（偏置） one over the other," he says.