The relationship between time to peak of fMRI-BOLD responses and difficulty of a task suggests neuronal origins to the BOLD contrast

摘要

Functional magnetic resonance imaging (fMRI) and its blood oxygen level contrast (BOLD) was used to study the response of the vibrissa system of rodents to different combinations of bilateral stimulations. We found that difficult tasks to perform, associated with longer neuronal periods, were correlated with larger times to peak (ttp) for the BOLD signal. This delay depended on number of vibrissa stimulated and the region of brain studied. By contrast, delay was not affected by which hemisphere was stimulated.