Investigation of layer-specific BOLD signal in the human visual cortex during visual attention

Directing spatial attention towards a particular stimulus location enhances cortical responses at corresponding regions in cortex. How attention modulates the laminar response profile within the attended region remains unclear, however. In this paper, we use high-field (7T) functional magnetic resonance imaging to investigate the effects of attention on laminar activity profiles in areas V1-V3 both when a stimulus was presented to the observer and in the absence of visual stimulation. Replicating previous findings, we find robust increases in the overall BOLD response for attended regions in cortex, both with and without visual stimulation. When analysing the BOLD response across the individual layers in visual cortex, we observed no evidence for laminar-specific differentiation with attention. We offer several potential explanations for these results, including theoretical, methodological and technical reasons. Additionally, we provide all data and pipelines openly in order to promote analytic consistency across layer-specific studies and improve reproducibility.