Zainab Haseeb¹, Anna Kosovicheva¹; ¹University of Toronto Mississauga

Visual performance varies across the visual field and differs between individuals, potentially contributing to errors in everyday tasks. These variations may stem from anatomical factors, such as photoreceptor density, as well as attentional factors, including the allocation of covert attention. This study investigated the relationship between individual differences in low-level spatial resolution and the distribution of covert attention across the visual field. In addition, we examined participants’ awareness of these performance differences across the visual field. Participants performed two distinct tasks: a line bisection task to evaluate low-level spatial resolution, and a visual search task to examine how covert attention is distributed across the visual field, while maintaining fixation at the center of the display. Stimuli were presented at 4º eccentricity across 4 cardinal and 4 diagonal locations. The bisection task measured spatial resolution by having participants judge whether the stem of a T-shape was offset to the left or right across ten levels (-0.12-0.12º). The second task assessed allocation of covert attention with a search task in which participants reported the orientation of a rotated T among Ls, placed in a random location around fixation. All stimuli were presented at the same 4º eccentricity. To assess whether participants were aware of their performance differences around the visual field, participants provided confidence ratings for their responses in both tasks. Results revealed no significant relationship between spatial resolution in the T-bisection task and accuracy in the search task, suggesting that these measures reflect distinct aspects of visual processing. This was further supported by confidence ratings, which tracked accuracy in the search task, but did not correlate with accuracy in the bisection task. Together, these findings point to distinct mechanisms underlying performance asymmetries around the visual field.

Acknowledgements: This work was supported by an NSERC Discovery Grant to AK