Structural impacts on the timing and amplitude of the negative BOLD response

The positive (PBR) and negative BOLD responses (NBR) arising in task-fMRI display varying magnitudes and dynamics across voxels. While the effects of structure, particularly of veins, on the PBR have been studied, little is known of NBR-structure relationships. Like the PBR, the NBR is often used as a surrogate marker of neuronal activation in both basic and clinical research and assessing its relationship with cortical structure may help interpret group differences. We therefore investigated how local structure affects BOLD amplitude and timing in PBR and NBR areas using multi-band fMRI during visual stimulation to obtain high temporal resolution (TR=0.45s) data combined with T1 imaging and susceptibility-weighted imaging (SWI) to quantify the local densities of gray/white matter and veins, respectively.
Source: Magnetic Resonance Imaging - Category: Radiology Authors: Tags: Original contribution Source Type: research