Feature-Specific Patterns of Attention and Functional Connectivity in Human Visual Cortex

The ability to successfully allocate attention to a particular space or feature in the visual world is vital for successful day-to-day functioning. Attention refers to a narrowing of focus, with increased processing of an attended attribute at the expense of other non-attended dimensions. This attentional mechanism can modulate activity in the visual cortex and beyond. However, the full range of spatial scales at which attentional effects are evident in the visual cortex as a function of task is still relatively little understood. This thesis aimed to investigate the effects of attentional modulation across the visual cortex at several spatial scales, examining activation at the level of mean activity in individual regions-of-interest (ROIs), comparing patterns of voxel-level activity, and employing connectivity-style approaches to examine communication between multiple visual areas simultaneously.