Who are the noisiest neighbors in the hood? Using error analyses to study the acquisition of letter-position processing.

This research examines the acquisition of letter-position processing. Study 1 investigated letter-position processing in Grades 1-6 and adult readers, using the occurrence of specific error types as the outcome measure. Between Grades 1 and 2, there was a shift from making more other-word to making more letter-position errors. This shift was a function of reading proficiency, not of years of reading instruction. Based on the multiple-route model of reading development (Grainger, Lété, Bertand, Dufau, & Ziegler, 2012), we argue that the fact that children make fewer other-word errors (i.e., mostly letter-identity errors) opens up the opportunity for them to make "the more advanced" letter-position errors. Finally, skilled adult readers still made fewer letter-position errors than typical readers in Grade 6, suggesting that the acquisition process is not finalized by the end of primary school. In Study 2, we directly compared letter-position processing with letter-identity processing. Thirty children in Grade 3 and 30 children in Grade 4 read aloud words with and without higher-frequency distractors. Children more often misread a word with a higher-frequency distractor than without such a distractor and this effect was stronger for below-average than for above-average readers. Converging with the results of Study 1, we found that a letter-position distractor is more disruptive than a letter-identity distractor. These results confirm that the acquisition of letter-position processing lags behind of that of letter-identity processing. The results are discussed within the framework of the Lexical Tuning Hypothesis (Castles, Davis, Cavalot, & Forster, 2007), which stresses the importance of feedback between letter (identity and position) coding and (developing) orthographic representations. (PsycINFO Database Record

Taking the Book from the Bookshelf: Masked Constituent Priming Effects from Compound Words and Nonwords.

Recent evidence from visual word recognition points to the important role of embedded words, suggesting that embedded words are activated independently of whether they are accompanied by an affix or a non-affix. The goal of the present research was to more closely examine the mechanisms involved in embedded word activation, particularly with respect to the "edge-alignedness" of the embedded word. We conducted two experiments that used masked priming in combination with lexical decision. In Experiment 1, monomorphemic target words were either preceded by a compound word prime (e.g., textbook-BOOK/textbook-TEXT), a compound-nonword prime (e.g., pilebook-BOOK/textpile-TEXT), a non-compound nonword prime (e.g., pimebook-BOOK/textpime-TEXT) or an unrelated prime (e.g., textjail-BOOK/jailbook-TEXT). The results revealed significant priming effects, not only in the compound word and compound-nonword conditions, but also in the non-compound nonword condition, suggesting that embedded words (e.g., book) were activated independently of whether they occurred in combination with a real morpheme (e.g., pilebook) or a non-morphemic constituent (e.g., pimebook). Priming in the compound word condition was greater than in the two nonword conditions, indicating that participants benefited from the whole-word representation of real compound words. Constituent priming occurred independently of whether the target word was the first or the second embedded constituent of the prime (e.g., textbook-BOOK vs. textbook-TEXT). In Experiment 2, significant priming effects were found for edge-aligned embedded constituents (e.g., pimebook-BOOK), but not for mid-embedded (e.g., pibookme-BOOK) or the outer-embedded constituents (e.g., bopimeok-BOOK), suggesting that edge-alignedness is a key factor determining the activation of embedded words.

Disentangling the developmental trajectories of letter position and letter identity coding using masked priming.

Masked transposed-letter (TL) priming effects have been used to index letter position processing over the course of reading development. Whereas some studies have reported an increase in TL priming over development, others have reported a decrease. These findings have led to the development of 2 somewhat contradictory accounts of letter position development: the lexical tuning hypothesis and the multiple-route model. One factor that may be contributing to these discrepancies is the use of baseline primes that substitute letters in the target word, which may confound the effect of changes in letter position processing over development with those of letter identity. The present study included an identity prime (e.g., listen-LISTEN), in addition to the standard two-substituted-letter (2SL; e.g., lidfen-LISTEN) and all-letter-different (ALD; e.g., rodfup-LISTEN) baselines, to remove the potential confound between letter position and letter identity information in determining the effect of the TL prime. Priming effects were measured in a lexical decision task administered to children aged 7-12 and a group of university students. Using inverse transformed response times, targets preceded by a TL prime were responded to significantly faster than those preceded by 2SL and ALD primes, and priming remained stable across development. In contrast, targets preceded by a TL prime were responded to significantly slower than those preceded by an ID prime, and this reaction-time cost increased significantly over development, with adults showing the largest cost. These findings are consistent with a lexical tuning account of letter position development, and are inconsistent with the multiple-route model. (PsycINFO Database Record

Word and pseudoword superiority effects on letter position processing in developing and skilled readers.

Studies have shown that letter position processing changes as reading develops. Whether these changes are driven by the development of the orthographic lexicon is currently unclear. In this study, we administered a novel variant of the Reicher-Wheeler task to children aged 7-12 years (Experiment 1) and adults (Experiment 2) to clarify the role of the developing lexicon in letter position processing. The task required participants to report the identity of a letter at a specified position within 3 orthographic contexts: anagram words (e.g., slime - which has the anagram partner, smile), pseudowords (e.g., blire - brile), and illegal nonwords (e.g., bfgsv - bsgfv). The influence of a reader's whole-word orthographic representations was investigated by comparing the performance of words to pseudowords (word superiority effect or WSE), and the influence of their knowledge of orthotactic constraints was investigated by comparing pseudowords to illegal nonwords (pseudoword superiority effect or PSE). While the PSE increased with developing orthographic skills (as indexed by irregular word reading) in primary schoolchildren, the WSE emerged only in adult readers. Furthermore, the size of the WSE increased with orthographic skill in adults. The findings are discussed in regards to current models and theories of visual word recognition and reading development. (PsycINFO Database Record

Morpho-orthographic segmentation without semantics.

Masked priming studies have repeatedly provided evidence for a form-based morpho-orthographic segmentation mechanism that blindly decomposes any word with the mere appearance of morphological complexity (e.g., corn + er). This account has been called into question by Baayen et al. Psychological Review, 118, 438-482 (2011), who pointed out that the prime words previously tested in the morpho-orthographic condition vary in the extent to which the suffix conveys regular meaning. In the present study, we investigated whether evidence for morpho-orthographic segmentation can be obtained with a set of tightly controlled prime words that are entirely semantically opaque. Using a visual lexical decision task, we compared priming from truly suffixed primes (hunter-HUNT), completely opaque pseudo-suffixed primes (corner-CORN), and non-suffixed primes (cashew-CASH). The results show comparable magnitudes of priming for the truly suffixed and pseudo-suffixed primes, and no priming from non-suffixed primes, and therefore provide further important evidence in support of morpho-orthographic segmentation processes operating in the absence of any possible role for semantics.

The locus of impairment in English developmental letter position dyslexia.

Many children with reading difficulties display phonological deficits and struggle to acquire non-lexical reading skills. However, not all children with reading difficulties have these problems, such as children with selective letter position dyslexia (LPD), who make excessive migration errors (such as reading slime as "smile"). Previous research has explored three possible loci for the deficit - the phonological output buffer, the orthographic input lexicon, and the orthographic-visual analysis stage of reading. While there is compelling evidence against a phonological output buffer and orthographic input lexicon deficit account of English LPD, the evidence in support of an orthographic-visual analysis deficit is currently limited. In this multiple single-case study with three English-speaking children with developmental LPD, we aimed to both replicate and extend previous findings regarding the locus of impairment in English LPD. First, we ruled out a phonological output buffer and an orthographic input lexicon deficit by administering tasks that directly assess phonological processing and lexical guessing. We then went on to directly assess whether or not children with LPD have an orthographic-visual analysis deficit by modifying two tasks that have previously been used to localize processing at this level: a same-different decision task and a non-word reading task. The results from these tasks indicate that LPD is most likely caused by a deficit specific to the coding of letter positions at the orthographic-visual analysis stage of reading. These findings provide further evidence for the heterogeneity of dyslexia and its underlying causes.