Figure 1.

Schematic illustration of the neurophysiological processes underpinning hemodynamic neuroimaging signals. The boxed processes linked by thick gray arrows around the outside represent components of interest to those focussing on “parametric neurovascular coupling,” whereas the more detailed processes illustrated in the center represent important concepts in for investigation of “physiological neurovascular coupling.” The relationships between the illustrated biophysical or physiological components, as well as the baseline conditions upon which changes are superimposed, may be mediated by the factors illustrated in Figure 6.