The Clock Counts – Length Effects in English Dyslexic Readers

Abstract

In reading, length effects (LEs) are defined as an increment in the time taken to read as a function of word length and may indicate whether reading is proceeding in an efficient whole word fashion or by serial letter processing. LEs are generally considered to be a pathognomonic symptom of developmental dyslexia (DD) and predominantly have been investigated in transparent orthographies where reading impairment is characterized as slow and effortful. In the present study a sample of 18 adult participants with DD were compared to a matched sample of typical developing readers to investigate whether the LE is a critical aspect of DD in an opaque orthography, English. We expected that the DD group would present with marked LEs, in both words and non-words, compared to typical developing readers. The presence of LEs in the DD group confirmed our prediction. These effects were particularly strong in low frequency words and in non-words, as observed in reading speed. These preliminary findings may have important theoretical implications for current understanding of DD.

Shallow or deep? The impact of orthographic depth on visual processing impairments in developmental dyslexia

“…Behrmann & Plaut, 2014;Roberts et al, 2013Roberts et al, , 2015. Interestingly, word length effects and impairments for non-orthographic visual stimuli (including objects and faces) have also been noted in both children and adults with DD (Gabay et al, 2017a;Provazza et al, 2019b;Sigurdardottir et al, 2018), strengthening the account of a VWFA dysfunction. It is therefore plausible to hypothesise that a failure in its engagement may result in a visual processing deficit (in addition to phonology) in DD.…”

“…Although phonology appears to be a contributing factor in DD, some studies demonstrate that a phonological deficit may be less important (Elliot & Grigorenko, 2014;Giofrè et al, 2019b;Provazza et al 2019b;Smith-Spark et al, 2003;Vidyasagar & Pammer, 2010). For instance, not all individuals with reading disabilities demonstrate a phonological deficit (Castles & Coltheart, 1993;Frederickson & Frith, 1998;Frith, 2017;White et al, 2006;Wolf & Bowers, 1999) and individuals with poor phonological abilities can nevertheless become competent readers (Elliot & Grigorenko, 2014;Howard, 1996).…”

“…Verhoeven et al, 2011) highlighting the salience of a multi-faceted account of the deficit as well as for other developmental disorders (see Astle & Fletcher-Watson, 2020;Elliot & Grigorenko, 2014;Gibbs & Elliott, 2020). Specifically, DD may also be characterised by other underlying impairments, such as a visual processing deficit that would prevent fluent word reading (Provazza et al, 2019b;Sigurdardottir et al, 2018;Stein & Fowler, 1981;Valdois et al, 2003).…”

Double Trouble: Visual and Phonological Impairments in English Dyslexic Readers

“…Such a result stresses the importance of phonology and not merely auditory processing in adults with DD. Furthermore, it would be interesting to evaluate processing skills in the phonological and visual domains of dyslexic readers within different cultures, particularly those reading different orthographies (e.g., transparent languages such as Italian, see Provazza et al, 2019 for some considerations about dyslexia in different languages). Finally, large-scale studies should be performed to understand whether dyslexia operates as an umbrella term encompassing several different problems, such as phonological and visual processing (Giofre et al, 2019).…”

Working memory profiles of children with reading difficulties who are learning to read in Greek

“…Briefly reported in a book chapter, the findings of this study indicate a specific impairment in phonological loop and central executive with an intact visuo‐spatial sketch pad in this group. Nevertheless, investigations amongst adult English speaking dyslexics indicate that they also struggle with visual tasks when greater attentional control is required (Provazza, Giofrè, Adams, and Roberts (2019).…”