Spatial Frequency Sensitivity Differences between Adults of Good and Poor Reading Ability

To determine whether normal adults of good and poor reading ability exhibit different patterns of sensitivity to spatial frequency, as previously found between dyslexic and nondyslexic control subjects. The visual acuity, spatial frequency sensitivity, and reading ability of 96 normal, nondyslexic adults was assessed. Participants were ranked according to reading ability. The top 50% were classified as good readers and the bottom 50% as poor readers. Despite no differences in visual acuity, good and poor readers showed different patterns of spatial frequency sensitivity. In particular, compared with good readers, poor readers showed reduced sensitivity to spatial frequencies between 2 and 6 cyc/deg, and no differences in sensitivity were found at lower or higher spatial frequencies. The findings indicate that spatial frequency sensitivity differences found previously between dyslexic and nondyslexic controls can extend to the normal (nondyslexic) adult population.