Quantifying the reliance on different sublexical correspondences in German and English

Developmental Dyslexia, Reading Acquisition, and Statistical Learning: A Sceptic's Guide

Many theories have been put forward that propose that developmental dyslexia is caused by low-level neural, cognitive, or perceptual deficits. For example, statistical learning is a cognitive mechanism that allows the learner to detect a probabilistic pattern in a stream of stimuli and to generalise the knowledge of this pattern to similar stimuli. The link between statistical learning and reading ability is indirect, with intermediate skills, such as knowledge of frequently co-occurring letters, likely being causally dependent on statistical learning skills and, in turn, causing individual variation in reading ability. We discuss theoretical issues regarding what a link between statistical learning and reading ability actually means and review the evidence for such a deficit. We then describe and simulate the "noisy chain hypothesis", where each intermediary link between a proposed cause and the end-state of reading ability reduces the correlation coefficient between the low-level deficit and the end-state outcome of reading. We draw the following conclusions: (1) Empirically, there is evidence for a correlation between statistical learning ability and reading ability, but there is no evidence to suggest that this relationship is causal, (2) theoretically, focussing on a complete causal chain between a distal cause and developmental dyslexia, rather than the two endpoints of the distal cause and reading ability only, is necessary for understanding the underlying processes, (3) statistically, the indirect nature of the link between statistical learning and reading ability means that the magnitude of the correlation is diluted by other influencing variables, yielding most studies to date underpowered, and (4) practically, it is unclear what can be gained from invoking the concept of statistical learning in teaching children to read.

Order among chaos: Cross-linguistic differences and developmental trajectories in pseudoword reading aloud using pronunciation Entropy

In this work we propose the use of Entropy to measure variability in pronunciations in pseudowords reading aloud: pseudowords where participants give many different pronunciations receive higher Entropy values. Monolingual adults, monolingual children, and bilingual children proficient in different European languages varying in orthographic depth were tested. We predicted that Entropy values will increase with increasing orthographic depth. Moreover, higher Entropy was expected for younger than older children, as reading experience improves the knowledge of grapheme-phoneme correspondences (GPCs). We also tested if interference from a second language would lead to higher Entropy. Results show that orthographic depth affects Entropy, but only when the items are not strictly matched across languages. We also found that Entropy decreases across age, suggesting that GPC knowledge becomes refined throughout grades 2-4. We found no differences between bilingual and monolingual children. Our results indicate that item characteristics play a fundamental role in pseudoword pronunciation variability, that reading experience is associated with reduced variability in responses, and that in bilinguals' knowledge of a second orthography does not seem to interfere with pseudoword reading aloud.

Variations in the use of simple and context-sensitive grapheme-phoneme correspondences in English and German developing readers

Learning to read in most alphabetic orthographies requires not only the acquisition of simple grapheme-phoneme correspondences (GPCs) but also the acquisition of context-sensitive GPCs, where surrounding letters change a grapheme's pronunciation. We aimed to explore the use and development of simple GPCs (e.g. a ➔ /æ/) and context-sensitive GPCs (e.g. [w]a ➔ /ɔ/, as in "swan" or a[l][d] ➔ /o:/, as in "bald") in pseudoword reading. Across three experiments, English- and German-speaking children in grades 2-4 read aloud pseudowords, where vowel graphemes had different pronunciations according to different contexts (e.g. "hact", "wact", "hald"). First, we found that children use context-sensitive GPCs from grade 2 onwards, even when they are not explicitly taught. Second, we used a mathematical optimisation procedure to assess whether children's vowel responses can be described by assuming that they rely on a mix of simple and context-sensitive GPCs. While the approach works well for German adults (Schmalz et al. in Journal of Cognitive Psychology, 26, 831-852, 2014), we found poor model fits for both German- and English-speaking children. Additional analyses using an entropy measure and data from a third experiment showed that children's pseudoword reading responses are variable and likely affected by random noise. We found a decrease in entropy across grade and reading ability across all conditions in both languages. This suggests that GPC knowledge becomes increasingly refined across grades 2-4.

Two distinct parsing stages in nonword reading aloud: Evidence from Russian

Word reading partly depends on the activation of sublexical letter clusters. Previous research has studied which types of letter clusters have psychological saliency, but less is known about cognitive mechanisms of letter string parsing. Here, we take advantage of the high degree of context-dependency of the Russian orthography to examine whether consonant–vowel (CV) clusters are treated as units in two stages of sublexical processing. In two experiments using a nonword reading task, we use two orthogonal manipulations: (a) insertion of a visual disruptor (#) to assess whether CV clusters are kept intact during the early visual parsing stage, and (b) presence of context-dependent grapheme–phoneme correspondences (GPCs; e.g., л[а] → /l/; л[я] → /lj/), to assess whether CV clusters remain intact or are split during the print-to-speech conversion stage. The results suggest that although CV clusters are initially processed as perceptual units in the early visual parsing stage, letters and not CV clusters drive print-to-speech conversion.

German and English Bodies: No Evidence for Cross-Linguistic Differences in Preferred Orthographic Grain Size

Previous studies have found that words and nonwords with many body neighbours (i.e., words with the same orthographic body, e.g., cat, brat, at) are read faster than items with fewer body neighbours. This body-N effect has been explored in the context of cross-linguistic differences in reading where it has been reported that the size of the effect differs as a function of orthographic depth: readers of English, a deep orthography, show stronger facilitation than readers of German, a shallow orthography. Such findings support the psycholinguistic grain size theory, which proposes that readers of English rely on large orthographic units to reduce ambiguity of print-to-speech correspondences in their orthography. Here we re-examine the evidence for this pattern and find that there is no reliable evidence for such a cross-linguistic difference. Re-analysis of a key study (Ziegler et al., 2001), analysis of data from the English Lexicon Project (Balota et al., 2007), and a large-scale analysis of nine new experiments all support this conclusion. Using Bayesian analysis techniques, we find little evidence of the body-N effect in most tasks and conditions. Where we do find evidence for a body-N effect (lexical decision for nonwords), we find evidence against an interaction with language.

Getting to the bottom of orthographic depth

Orthographic depth has been studied intensively as one of the sources of cross-linguistic differences in reading, and yet there has been little detailed analysis of what is meant by orthographic depth. Here we propose that orthographic depth is a conglomerate of two separate constructs: the complexity of print-to-speech correspondences and the unpredictability of the derivation of the pronunciations of words on the basis of their orthography. We show that on a linguistic level, these two concepts can be dissociated. Furthermore, we make different predictions about how the two concepts would affect skilled reading and reading acquisition. We argue that refining the definition of orthographic depth opens up new research questions. Addressing these can provide insights into the specific mechanisms by which language-level orthographic properties affect cognitive processes underlying reading.