The development of print tuning in children with dyslexia: Evidence from longitudinal ERP data supported by fMRI

Lexical and sublexical orthographic processing: An ERP study with skilled and dyslexic adult readers

“…3 reveals that at the majority of posterior sites (e.g., PO3/PO4) the N1 response to pseudowords, although weaker, tends to peak slightly earlier than the response to symbol-sequences and this effect is more clearly present over the left hemisphere. In addition, similarly to previous studies (e.g., Maurer et al, 2005Maurer et al, , 2011, pseudowords and symbolsequences evoked responses already in the earlier P1 component, reflecting that letter-specific processing in adults is under way as early as 80-120 ms. Taken together, the observed ERP activity is compatible with the idea that reading acquisition, and skilled processing of letters, drives the emergence of a perceptual mechanism specifically attuned to the properties of the orthographic code, signaled by the P1/N1 electrophysiological response Maurer et al, 2005Maurer et al, , 2006McCandliss et al, 2003). We note that in earlier ERP studies using false-font instead to better control for low-level visual differences with letters, print tuning effects were still robust (Eberhard-Moscicka et al, 2014), suggesting that the effects shown in studies using symbol strings are not due to low-level differences.…”

“…The N1 is a negative deflection peaking at approximately 150-200 ms post stimulus onset, which is significantly enhanced to orthographic strings (vs. non-orthographic items like symbols) in the left occipitotemporal region (e.g., Bentin, Mouchetant-Rostaing, Giard, Echallier, & Pernier, 1999;Brem et al, 2009;Maurer et al, 2005; for an overview, see Maurer & McCandliss, 2007), and might therefore be a neural index of the reduced specialization for written word processing in reading disorders like dyslexia. Similar effects have been found in the preceding P1 component ($50-150 ms; e.g., Maurer et al, 2005Maurer et al, , 2011 and the early P1-N1 peak(s) might reflect a reorganization of the brain that occurs as a function of reading training. For example, in a longitudinal study demonstrated that over the course of kindergarten to the second grade, there is an increased activation in response to visual words that occurs around 150-270 ms.…”

“…To provide a complete scenario, we further manipulated reading competence, so average and impaired dyslexic readers were compared as a between-subject factor. In the recent years, an increasing number of studies have provided evidence for a failure in orthographic processing in dyslexia, as expressed by behavioral (Araújo, Faísca, Bramão, Petersson, & Reis, 2014;Bergmann & Wimmer, 2008;Marinelli, Angelelli, Notarnicola, & Luzzatti, 2009;Marinus & de Jong, 2010) and neural correlates such as dyslexic vOT under activation (Hawelka, Gagl, & Wimmer, 2010;Maurer et al, , 2011van der Mark et al, 2009;Wimmer et al, 2010) or absent modulations of N1 responses to letter strings vs. symbols . Considering previous interpretations of impaired vOT orthographic processing in dyslexia as a tuning deficit at sublexical or lexical level van der Mark et al, 2009;Wimmer et al, 2010), we would expect a condition-specific group effect in N1 waveform as well, depending on whether this component reflects processing at these levels (since selective responses to letters in the N1 time window most likely originate from the inferior occipitotemporal cortex; Maurer & McCandliss, 2007;Tarkiainen, Helenius, Hansan, Cornelissen, & Salmelin, 1999).…”

Print-specific multimodal brain activation in kindergarten improves prediction of reading skills in second grade

“…Previous studies showed that print sensitivity is diminished in young dyslexic children (Maurer et al, 2007) but may normalise after they have gained experience with reading (Maurer et al, 2011) although dyslexic adults also show deficient sensitivity (Helenius et al, 1999;Shaywitz and Shaywitz, 2005). Together with the recent finding of clear functional and structural alterations in the left occipito-temporal cortex (Raschle et al, 2011;Specht et al, 2009) of preschool children with a familial risk of dyslexia, these studies thus clearly point to the potential power of print sensitivity as an index for successful reading acquisition.…”

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

“…It is indispensable that hypotheses from cross-sectional studies are validated by longitudinal studies. Some such investigations have already been carried out (Bradley, Corwyn, Burchinal, McAdoo, & Garcia Coll, 2001;Bus, Van IJzendoorn, & Pellegrini, 1995;Linkersdörfer et al, 2015;Lyytinen, Erskine, Hämä-läinen, Torppa, & Ronimus, 2015;Maurer et al, 2011;Wimmer, Mayringer, & Landerl, 2000) or are currently being conducted. It is important that future longitudinal studies are large-scale enough to include enough individuals who will develop dyslexia (i.e.…”