Information Processing in Near Peripheral Vision

Abstract

The present study required that Ss name briefly exposed single lower-case letters that were presented at a total of 24 locations (8 meridians X 3 retinal eccentricities, 0.5 degrees, 2.75 degrees, and 5.0 degrees from a central fixation point, 0 degrees). One group of 12 Ss received a set size (load) of 2 letters, and another group of 12 Ss received a set size (load) of 24 letters. Ss given the larger load were significantly less accurate and significantly slower (longer vocal latencies) in naming the letters. In addition, significant main effects of retinal eccentricity and meridian were found. Ss performed more poorly as the stimuli were presented more eccentrically. Also, performance tended to be somewhat poorer above and below the fixation point than it did left or right of fixation. There was also some tendency toward a right visual field superiority. Unlike an earlier study, there was little evidence in favor of a "tunnel vision" interpretation, which would have required an interaction of load X retinal eccentricity. Possible reasons for the different results from the two studies are discussed in terms of a levels-of-processing interpretation.