Visual localization in dyslexia

Individuals with specific reading disability (SRD) may exhibit visual psych ophysical abnormalities that include prolonged visual persistence, decrease d luminance contrast sensitivity, lower flicker fusion thresholds, abnormal metacontrast masking, and lower motion detection sensitivity. These abnorm alities could result from impairment of the magnocellular division of the v isual afferent pathway to the cortex. The authors predicted that an impairm ent of this pathway would also cause abnormalities in ability to localize v isual stimuli. This prediction was tested in 2 experiments. Results of both experiments showed that adults who reported a history of SRD and who curre ntly had lower reading performance were less able than non-SRD participants to report the locations of small visual stimuli that were briefly flashed at positions similar to the ends of lines of text.