Reading proficiency predicts the extent of the right, but not left, perceptual span in older readers.

The gaze-contingent moving-window paradigm was used to assess the size and symmetry of the perceptual span in older readers. The eye movements of 49 cognitively intact older adults (60-88 years of age) were recorded as they read sentences varying in difficulty, and the availability of letter information to the right and left of fixation was manipulated. To reconcile discrepancies in previous estimates of the perceptual span in older readers, individual differences in written language proficiency were assessed with tests of vocabulary, reading comprehension, reading speed, spelling ability, and print exposure. The results revealed that higher proficiency older adults extracted information up to 15 letter spaces to the right of fixation, while lower proficiency readers showed no additional benefit beyond 9 letters to the right. However, all readers showed improvements to reading with the availability of up to 9 letters to the left-confirming previous evidence of reduced perceptual span asymmetry in older readers. The findings raise questions about whether the source of age-related changes in parafoveal processing lies in the adoption of a risky reading strategy involving an increased propensity to both guess upcoming words and make corrective regressions.