Visual perceptual learning is similar across the extrafoveal central visual fields

Abstract

Visual perceptual learning occurs with the presentation of novel visual stimuli at retinal sites near the fovea to 20 degrees eccentricities. It was unclear if the magnitude and rate of visual learning were similar across the central visual fields or if visual learning decreased with increasing eccentricity. The robustness of learning across the visual fields may affect the magnitude of computer-aided visual recovery after visual brain injury. Therefore we determined if eccentricity was a factor that influenced perceptual learning. Subjects were trained to detect the presence or absence of a single line oriented differently (odd-element) from an array of lines that otherwise had the same orientation. The odd-element line was presented 3 degrees, 9 degrees or 18 degrees from fixation. Perceptual performance improved during training trials with a similar magnitude and similar learning curve slopes at all 3 eccentricities. Pre- and post-training performance improved to a similar magnitude at 3 vs 9 degrees in 4 of 4 subjects tested and at 9 degrees vs 18 degrees in 4 of 5 subjects. In the fifth subject there was no post-training improvement in performance at 18 degrees. Visual perceptual learning is similar across the extrafoveal central visual fields in almost all subjects.