Laminar imaging of positive and negative BOLD in human visual cortex at 7Â T

Here we use half-millimeter human functional and structural magnetic resonance imaging (fMRI, MRI) to derive laminar profiles in early visual cortex using a paradigm known to elicit two separate responses originating from an excitatory and a suppressive source, avoiding any contamination due to blood-stealing. We report the shape of laminar blood level oxygenation level dependent (BOLD) profiles from the excitatory and suppressive conditions. We analyse positive and negative %BOLD laminar profiles with respect to the dominating linear trend towards the pial surface, a confounding feature of gradient echo BOLD fMRI, and examine the correspondence with the anatomical landmark of input-related signals in primary visual cortex, the stria of Gennari.