Global relationship between anatomical connectivity and activity propagation in the cerebral cortex

Anatomical connectivity is a prerequisite for cooperative interactions betw een cortical areas, but it has yet to be demonstrated that association fibr e networks determine the macroscopical flow of activity in the cerebral cor tex. To test this notion, we constructed a large-scale model of cortical ar eas whose interconnections were based on published anatomical data from tra cing studies. Using this model we simulated the propagation of activity in response to activation of individual cortical areas and compared the result ing topographic activation patterns to electrophysiological observations on the global spread of epileptic activity following intracortical stimulatio n. Here we show that a neural network with connectivity derived from experi mental data reproduces cortical propagation of activity significantly bette r than networks with different types of neighbourhood-based connectivity or random connections. Our results indicate that association fibres and their relative connection strengths are useful predictors of global topographic activation patterns in the cerebral cortex. This global structure-function relationship may open a door to explicit interpretation of cortical activat ion data in terms of underlying anatomical connectivity.