Separation of sensory and attention input to the human primary somatosensory cortex by spin- and gradient-echo BOLD fMRI

High spatial resolution laminar specific fMRI has a potential to separate between top-down and bottom-up signals. In this study, we investigated the effect of attention across cortical layers in the human S1 using SAGE-EPI sequence. fMRI experiments during vibrotactile stimulation with passive and attention tasks with 0.8mm isotropic resolution at 7T were performed. We demonstrated that the SE-BOLD can identify laminar profiles of bottom-up and top-down processes: the laminar profile of passive task showed the peak at layer 4, but that of attention task showed the peak at the superficial layers.