The effect of stimulus duration and monocular viewing on the "oblique effect" in peripheral vision.

Luminance thresholds were obtained for narrow bars of light in vertical, horizontal and oblique orientations. From 5 degrees to 60 degrees into the periphery, a small but significant elevation in threshold was found for stimuli in oblique orientations. The monocularly obtained data replicate an earlier report using binocular presentations and a stimulus duration of 100 msec. When exposure time was 10 msec or 500 msec, this effect of orientation broke down. Theoretical implications are discussed.