Cover picture: The spatiotemporal evolution of perfusion-related functional imaging signals demonstrates etiology-dependent differences. Cerebral blood volume (CBV) signals (top four images) center on activated pial arterioles and evolve with spatial similarity across time and graded stimulation. Oxygenation responses (bottom four images) originate in the capillary bed and metamorphose into large draining veins. Understanding the differences between these responses, in terms of both spatiotemporal profile and their relationship to underlying neuronal activity, will influence the development and interpretation of functional brainmapping strategies. For details, see the article by Nemoto et al. in this issue (pages 3850–3861).