Distinguishing cause from effect – many deficits associated with developmental dyslexia may be a consequence of reduced and suboptimal reading experience

Abstract

(2018) Distinguishing cause from effect -many deficits associated with developmental dyslexia may be a consequence of reduced and suboptimal reading experience, Language, Cognition and Neuroscience, 33:3, 333-350, DOI: 10.1080/23273798.2017 The cause of developmental dyslexia is still unknown despite decades of intense research. Many causal explanations have been proposed, based on the range of impairments displayed by affected individuals. Here we draw attention to the fact that many of these impairments are also shown by illiterate individuals who have not received any or very little reading instruction. We suggest that this fact may not be coincidental and that the performance differences of both illiterates and individuals with dyslexia compared to literate controls are, to a substantial extent, secondary consequences of either reduced or suboptimal reading experience or a combination of both. The search for the primary causes of reading impairments will make progress if the consequences of quantitative and qualitative differences in reading experience are better taken into account and not mistaken for the causes of reading disorders. We close by providing four recommendations for future research.ARTICLE HISTORY

Learning to read facilitates the retrieval of phonological representations in rapid automatized naming: Evidence from unschooled illiterate, ex‐illiterate, and schooled literate adults

“…Peterson et al, ) and may cause researchers to revisit the causal role of RAN in developmental dyslexia (cf. Huettig et al, ). Relatedly, these results can be relevant for neuropsychological/psychoeducational assessment.…”

“…Whereas, some developmental studies reported a unidirectional effect of (early) RAN on later reading skills (Lervåg & Hulme, ; Verhagen, Aarnoutse, & van Leeuwe, ; Wei, Georgiou, & Deng, ), others found a reciprocal relation between RAN and reading (Compton, ; Peterson et al, ; Wolff, ), and hence, reading experience is not only influenced by but is also a causal influence on RAN (cf. Huettig, Lachmann, Reis, & Petersson, ). Indeed, in a recent longitudinal study from prekindergarten to fourth‐grade, Peterson et al () did find evidence for a causal effect of early reading skills on children's RAN but only at the very beginning of literacy acquisition (while the relation was reversed in older children).…”

“…Taken together these longitudinal studies can best be summarized as evidence for a bidirectional relationship between reading and RAN. It is important to note, however, that although longitudinal designs are usually powerful (Goswami, ; Huettig et al, ), the literacy‐RAN link is moderated by development and thus intrinsically confounded with neural maturation and also with schooling in such studies. Therefore, these studies preclude the possibility to examine in a fine‐grained manner the causal‐consequence direction from learning to read to RAN.…”

How many words do we read per minute? A review and meta-analysis of reading rate

“…There is a related literature on factors correlating with dyslexia (e.g.,Huettig, Lachmann, Reis, & Petersson, 2018), which is not covered here unless it can be assumed that the variables also correlate with individual differences in normal reading rate.…”

The culturally co-opted brain: how literacy affects the human mind

“…Huettig, Lachmann, Reis, and Petersson (2018) suggest that many deficits associated with developmental dyslexia are in fact a consequence of reduced and/or suboptimal reading experience. They point out that almost all deficits observed in individuals with dyslexia have also been observed in illiterate and low literate people.…”