Purpose: Visual functions vary with retinal eccentricity. Spatial resolution declines rapidly with eccentricity, while motion discrimination is sometimes better in the periphery than in the central field. Visual attention usually involves the central field, but this might be an indirect result of demands for spatial resolution. The present study investigated peripheral vision of stationary and moving patterns under varied attentional demands, with multiple stimuli in both central and peripheral fields.

Method: Grating patches were displayed on three adjacent video monitors, in the central field and at ± 30 deg eccentricity. Temporal thresholds were measured for motion direction discriminations; and orientation discrimination thresholds were measured for stationary gratings. In most conditions, 2 - 6 stimuli appeared simultaneously (1 or 2 on each monitor); and the target was cued by a pointer before, during, or after the multi-stimulus array. Discriminations in multi-stimulus conditions were compared with those in single-stimulus baseline conditions.

Results & conclusions: Peripheral vision differed for stationary and moving patterns. Greater attentional demands and more complex stimulus arrays produced poorer discriminations especially in the periphery, but this peripheral decline was much greater for stationary than for moving patterns. Moreover, for stationary patterns, central and peripheral vision were competitive, with central discriminations hindering peripheral discriminations. For moving patterns, the competition between central and peripheral vision was negligible. Evidently, multiple stationary stimuli are visually competitive, but moving patterns are processed more cooperatively.