Jozien Goense1, Nikos K. Logothetis1,2
1Dept. of Physiology of Cognitive Processes, Max-Planck Institute for Biological Cybernetics, Tuebingen, Germany; 2Division of Imaging Science & Biomedical Engineering, University of Manchester, United Kingdom
While the dynamics and mechanism of the positive BOLD response have been well studied, much less is known about the mechanism of the negative BOLD response. We studied the properties of the negative BOLD response by comparing the BOLD-, functional CBV- and CBF-responses in regions exhibiting positive and negative BOLD in primary visual cortex (V1) of anesthetized monkeys. Both positive and negative BOLD signals were accompanied by increases in CBV, although CBF was decreased in the unstimulated region.