Discrimination of reversible mirrored letters (e.g., d and b) poses a challenge when learning to read as it requires overcoming "mirror invariance," an evolutionary-old perceptual tendency of processing mirror images as equivalent. The present study investigated "when," in reading development, mirror-image discrimination…

The authors used a multiple-baseline-across-behaviors (i.e., word lists) design to evaluate a computer-based flashcard intervention on automatic sight-word reading in a 4th-grade student with moderate to severe intellectual disabilities. Immediately after the intervention was applied to each of three lists of sight words, the student made rapid…