Temporal dynamics of early visual word processing – Early versus late N1 sensitivity in children and adults

Abstract

In the course of reading development children become familiar with letter strings and learn to distinguish between lexical and non-lexical items. In previous studies, the N1 component of the ERP was shown to reflect print tuning but also to be sensitive to lexical effects. It remains unclear, however, whether these two aspects of orthographic processing occur at the same time or in different time windows during the lengthy N1 component. Moreover, it is unclear whether these processes develop late or occur already at early stages of literacy acquisition and whether this is similar for native languages and languages acquired later in life. To address these questions, 27 children were tested longitudinally, i.e. before (mean: 7.6 years) and after one year of classroom-based English instruction. Additionally, 22 adult speakers of English as a foreign language (mean: 25.1 years) were investigated. A 128-channel EEG was recorded while participants performed a one-back task with native German words, English words, pseudowords and false-font strings. The event-related EEG analysis of early and late N1 phases revealed early effects related to print tuning and late effects related to lexical processing in the native, but not in the second language of adult readers. In the absence of lexicality effects in children, print tuning effects were found across both early and late N1 segments. The temporally distinct N1 sensitivities to print and lexicality reflect temporal dynamics of visual word processing, which seem to depend on reading expertise or maturation.

Early Brain Sensitivity to Word Frequency and Lexicality During Reading Aloud and Implicit Reading

“…In this study, we refrained from testing coarse neural tuning for print, as indexed by differences in amplitudes between letter and symbols strings (therefore, symbols were not included in the material). Robust print tuning effects in the visual N1 have already been demonstrated elsewhere, at the group (e.g., Maurer et al., 2006, 2007; Brem et al., 2009; Araújo et al., 2012) and individual level (Eberhard-Moscicka et al., 2016). However, studies do not agree in finding differences between different kinds of letter strings such as lexicality and frequency effects.…”

“…But again, lexicality effects on N1 have not been reliably found in children (Kast et al., 2010; Araújo et al., 2012; Hasko et al., 2013; Eberhard-Moscicka et al., 2015). All together, these results seem to suggest that N1 sensitivity to word frequency and lexicality depends on the phase of reading development, as well as on reading expertise (Araújo et al., 2015; Eberhard-Moscicka et al., 2015, 2016). However, in other studies, neither adults nor children processed pseudowords differently than words in the N1 component (Maurer et al., 2005b) or adults did not exhibit a N1 specialization for words over pseudowords in contrast to children who showed larger amplitudes for words (Maurer et al., 2006).…”

“…A related question is whether and how the linguistic intention of the subject (given the task goals) could affect N1 sensitivity to the lexico-semantic properties of a written word. To date, mainly implicit word-processing tasks were used to study early visual processing, such as repetition detection (e.g., Maurer et al., 2006; Eberhard-Moscicka et al., 2015, 2016), lexical decision (a general measure of “wordlikness”, e.g., Kast et al., 2010; Mahé et al., 2012), or other variants of implicit reading (Araújo et al., 2012, 2015). However, using these implicit tasks as a proxy of reading in real life may not be as straightforward: in these tasks, participants had no conscious intention to engage in linguistic processing, and the focus is presumably on visual word form rather than grapheme-to-phoneme conversion.…”

N1 lateralization and dyslexia: An event‐related potential study in children with a familial risk of dyslexia

“…Xue, Jiang, Chen, and Dong () showed that the N1 lexicality effect is also modulated by factors such as familiarity of the script and stimulus length. Recently, Eberhard‐Moscicka, Jost, Fehlbaum, Pfenninger, and Maurer () found that the first and the second subcomponent of the N1 are sensitive to course print tuning in children, whereas in adults only the first subcomponent is sensitive to course print tuning and the second subcomponent is sensitive to the lexicality effect, but only in the participants' native language German and not in the second language English. Zhao et al () found that the N1 was larger in response to words than consonant strings among 7‐year‐old readers with a high reading ability in contrast to readers with a low reading ability.…”

Scalp Topography of Lower Urinary Tract Sensory Evoked Potentials

“…On the other hand, mean amplitude was calculated for time windows defined based on the group mean peak latencies (± 2 standard deviations (SD)) of the individually set P1 (Cz–Fz: 43–79 ms; Cz–AvgRef: 43–79 ms), N1 (Cz–Fz: 87–147 ms; Cz–AvgRef: 88–148 ms), and P2 (Cz–Fz: 210-302 ms; Cz–AvgRef: 220–300 ms) markers (n = 222) of the difference channels. In addition, time windows for specific SEP components were chosen in an unbiased way independent from specific channels (Albrecht et al 2005 ; Eberhard-Moscicka et al 2016 ; Meyer et al 2007 ) using the global field power (GFP) as a global measure of the map strength (root mean square of all voltages in a map) representing the SD across all channels (Fig. 2 d).…”