Identification of letters embedded in briefly presented words (e.g., TABLE), pseudowords (e.g., TOBLE), and illegal nonwords (e.g., TPBFE) was measured using the Reicher-Wheeler paradigm. Children diagnosed as dyslexic and showing a clear disadvantage in recognizing and reading aloud words and pseudowords (compared to chronological age-matched controls) showed a pattern of results that was qualitatively identical to both reading age and chronological age control children. In all three groups a small nonsignificant advantage was obtained for letter identification in words compared to pseudowords, and a massive advantage for letter identification in pseudowords compared to illegal nonwords. A group of adult participants tested with the same materials showed the classic word superiority effect as well as a pseudoword advantage over illegal nonwords. These results suggest that the pseudoword superiority effect is subtended by regularities operating at the level of sublexical orthographic representations (orthotactic constraints). This phenomenon could provide a useful tool for future investigations of the development of orthotactic constraints during reading acquisition. (C) 2003 Elsevier Science (USA). All rights reserved.