In several meditation traditions, practitioners engage in a form of sustained, spatially directed visual attention which can lead to an alteration in visual perception and awareness. To understand how this state arises, it is important to identify the neural circuitry that underlies the sustained spatial attention technique and to characterize its effects on the mechanisms of visual perception. Functional magnetic resonance imaging (fMRI) is used to monitor brain activity in the visual cortex during sustained visuospatial attention. Retinotopic mapping is used to identify early visual areas and high level attention-related areas, including the frontal eye fields and the lateral intraparietal lobe. Participants direct sustained visual attention to a visual stimulus presented to the left or right visual field. Functional connectivity between retinotopically-defined visual areas is assessed using coherency analysis. Ongoing work should provide insight into brain networks mediating sustained spatial attention, and how communication between these regions correlates with the depth of attentional focus.