Neural activations are mostly circularly stimulated. A neuron is activated by other neurons to which it is connected. In turn, its own activation stimulates other connected neurons to activation. If an impulse is started at any one place on the axon, it propagates in both directions.


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[[Functional connectivity]] is defined as the temporal dependency of [[neuronal activation]] patterns of anatomically separated brain regions and in the past years an increasing body of neuroimaging studies has started to explore functional connectivity by measuring the level of co-activation of [[resting state functional magnetic resonance imaging]] time-series between brain regions.