Attention Alters Population Spatial Frequency Tuning.

Spatial frequency (SF) selectivity serves as a fundamental building block within the visual system, determining what we can and cannot see. Attention is theorized to augment the visibility of items in our environment by changing how we process SFs. However, the specific neural mechanisms underlying this effect remain unclear, particularly in humans. Here, we used functional magnetic resonance imaging to measure voxel-wise population SF tuning (pSFT), which allowed us to examine how attention alters the SF response profiles of neural populations in the early visual cortex (V1-V3). In the scanner, participants (five female, three male) were cued to covertly attend to one of two spatially competing letter streams, each defined by low or high SF content. This task promoted feature-based attention directed to a particular SF, as well as the suppression of the irrelevant stream's SF. Concurrently, we measured pSFT in a task-irrelevant hemifield to examine how the known spatial spread of feature-based attention influenced the SF tuning properties of neurons sampled within a voxel. We discovered that attention elicited attractive shifts in SF preference, toward the attended SF. This suggests that attention can profoundly influence populations of SF preference across the visual field, depending on task goals and native neural preferences.