The developmental trend of transposed letters effects in masked priming

Individual differences and the transposed letter effect during reading

When a preview contains substituted letters (SL; markey) word identification is more disrupted for a target word (monkey), compared to when the preview contains transposed letters (TL; mnokey). The transposed letter effect demonstrates that letter positions are encoded more flexibly than letter identities, and is a robust finding in adults. However, letter position encoding has been shown to gradually become more flexible as reading skills develop. It is unclear whether letter position encoding flexibility reaches maturation in skilled adult readers, or whether some differences in the magnitude of the TL effect remain in relation to individual differences in cognitive skills. We examined 100 skilled adult readers who read sentences containing a correct, TL or SL preview. Previews were replaced by the correct target word when the reader's gaze triggered an invisible boundary. Cognitive skills were assessed and grouped based on overlapping variance via Principal Components Analysis (PCA) and subsequently used to predict eye movement measures for each condition. Consistent with previous literature, adult readers were found to generally encode letter position more flexibly than letter identity. Very few differences were found in the magnitude of TL effects between adults based on individual differences in cognitive skills. The flexibility of letter position encoding appears to reach maturation (or near maturation) in skilled adult readers.

Consonant and vowel transposition effects during reading development: A study on Italian children and adults

Recently, Colombo, Spinelli, and Lupker, using a masked transposed letter (TL) priming paradigm, investigated whether consonant/vowel (CV) status is important early in orthographic processing. In four experiments with Italian and English adults, they found equivalent TL priming effects for CC, CV, and VC transpositions. Here, we investigated that question with younger readers (aged 7-10) and adults, as well as whether masked TL priming effects might have a phonological basis. That is, because young children are likely to use phonological recoding in reading, the question was whether they would show TL priming that is affected by CV status. In Experiment 1, target words were preceded by primes in which two letters (either CV, VC, or CC) were transposed versus substituted (SL). We found significant TL priming effects, with an increasing developmental trend but, again, no letter type by priming interaction. In Experiment 2, the transpositions/substitutions involved only pairs of vowels with those vowels having either diphthong or hiatus status. The difference between these two types of vowel clusters is only phonological; thus, the question was, "Would TL priming interact with this factor?" TL priming was again found with an increasing trend with age, but there was no vowel cluster by priming interaction. There was, however, an overall vowel cluster effect (slower responding to words with hiatuses) which decreased with age. The results suggest that TL priming only taps the orthographic level, and that CV status only becomes important at a later phonological level.