Mapping stimulus-driven hemodynamic changes in white matter using 7T high-resolution fMRI

In this study, by integrating 7T high-resolution imaging and massive data averaging, we show that white matter fMRI activations can be detected at a single-voxel level. Hemodynamic changes evoked by the flickering checkerboard stimuli were not homogenous within the optic radiation, and the averaged pattern exhibited a delayed time to peak longer than V1, consistent with previous literature. The current datasets also revealed stimulus-locked changes in certain white-matter tracts beyond the visual pathway.