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Maurer, U.

Publications and source records attributed to Maurer, U..

7 recordsLinked to original sources

Hierarchical Predictive Processing during Natural Reading

Key neural mechanisms underlying reading, especially in the context of sentences and texts, remain elusive. An influential theory states that the brain rapidly generates a hierarchy of probabilistic predictions about upcoming words at multiple levels of linguistic representation. When encountering a word, a reader integrates sensory input with the linguistic predictions, and rely on the resulting prediction error signals to achieve efficient comprehension. Here, we tested this hierarchical predictive account with a natural reading task while EEG and eye movements were simultaneously recorded. We find distinct prediction error signals attributable to word contextual, lexical, and orthographic levels of predictions. These prediction error signals exhibit a temporal order. Our results also indicate that context-based predictions rapidly constrain orthographic-level predictions. We thus provide evidence for a hierarchical predictive process central to efficient natural reading.

neuroscience↗

Posterior Periodic Alpha Power as a Neural Marker of Early Biliteracy Skills: The Mediating Role of Rapid Automatized Naming in Chinese-English Bilingual Children

In school-aged children, resting-state posterior alpha activity has been linked to thalamocortical signal coordination and literacy-related cognition. However, findings are mixed, partly because conventional band power measures conflate oscillatory (periodic) activity with the broadband aperiodic (1/f) background. We tested Chinese-English bilingual children in Grades 1 to 5 (N = 121; 72 families; mean age = 8.23 years, SD = 0.81) to examine if posterior periodic alpha power (8-12 Hz), isolated from aperiodic components, predicts foundational biliteracy skills (Chinese and English word reading and dictation). We also tested whether Chinese digit rapid automatized naming (CDRAN) mediates these associations. In regression models that accounted for family clustering and controlled for age, socioeconomic status (SES), and aperiodic components (exponent and offset), higher periodic alpha power uniquely predicted better performance on all four literacy outcomes. In structural equation models that accounted for family clustering, periodic alpha power predicted CDRAN ({beta} = .213, p = .011), and CDRAN significantly predicted Chinese word reading ({beta} = .442, p < .001), Chinese dictation ({beta} = .346, p = .003), English word reading ({beta} = .302, p < .001), and English dictation ({beta} = .349, p < .001). Indirect effects via CDRAN were significant for all outcomes. These findings suggest that aperiodic-adjusted periodic alpha power is associated with biliteracy variation across Chinese and English and that its association with biliteracy operates in part through rapid serial naming efficiency.

neuroscience↗

Deviant functional connectivity patterns in the EEG and their potential use for dyslexia screening

Developmental dyslexia (DD) is a common learning disorder with potential neural origins. While EEG-based brain activation measures combined with machine learning have shown promise for DD screening, these approaches often lack validation on independent participants, which is a crucial step for practical application. This study developed an EEG-based screening approach and investigated the neural correlates of DD in Chinese children. EEG signals were recorded from 130 children (82 with DD, 48 typically developing) aged betweeen 7 and 11 during resting-state and working memory tasks. The EEG data were preprocessed into clean segments to compute functional connectivity (FC) matrices across four frequency bands (delta, theta, alpha, beta). The segments were split into two independent samples, ensuring independence at the participant level: Sample 1, used for training and five-fold cross validation of the convolutional neural networks, and Sample 2, used for cross-sample validation with the trained model. The beta-band FC index in the eyes-open condition achieved the highest within-sample classification accuracy (98%) and cross-sample accuracy (70%, p < .001). Discriminative FC patterns revealed that children with DD exhibited reduced temporal-parietal and central connectivity but increased frontal-central connectivity, likely reflecting compensatory mechanisms. Within the DD group, stronger FCs showed significant negative correlations with Chinese word reading accuracy and fluency. These findings suggest that EEG-based FC measures can effectively distinguish DD and reveal neural markers associated with impaired reading performance. This approach shows promise for noninvasive screening and deeper insight into the neural basis of DD, particularly in non-alphabetic language systems.

neuroscience↗

Neural mechanism underlying preview effects and masked priming effects in visual word processing

Two classic experimental paradigms - masked repetition priming and the boundary paradigm - have played a pivotal role in understanding the process of visual word recognition. Traditionally, these paradigms have often been employed by different communities of researchers, with their own long-standing research traditions. Nevertheless, a review of the literature suggests that the brain-electric correlates of word processing established with both paradigms may show interesting similarities, in particular with regard to the location, timing, and direction of N1 and N250 effects. However, as of yet, no direct comparison has been undertaken between both paradigms. In the current study, we used combined eye-tracking/EEG to perform such a within-subject comparison using the same materials (single Chinese characters) as stimuli. Our results show the typical early repetition effects of N1 and N250 for both paradigms. However, repetition effects in N250 (i.e., a reduced negativity following identical-word primes/previews as compared to different-word primes/previews) were larger in the boundary paradigm than with masked priming. For N1 effects, repetition effects were similar across the two paradigms showing a larger N1 after repetitions as compared to alternations. Therefore, the results indicate that at the neural level, a briefly presented and masked foveal prime produces qualitatively similar facilitatory effects on visual word recognition as a parafoveal preview before a saccade, although such effects appear to be stronger in the latter case.

neuroscience↗

How the dominant reading direction changes parafoveal processing: A combined EEG/eye-tracking study

Reading directions vary across writing systems. Through long-term experience readers adjust their visual systems to the dominant reading direction in their writing systems. However, little is known about the neural correlates underlying these adjustments because different writing systems do not just differ in reading direction, but also regarding visual and linguistic properties. Here, we took advantage that Chinese is read to different degrees in left-right or top-down directions in different regions. We investigated visual word processing in participants from Taiwan (both top-down and left-right directions) and from mainland China (only left-right direction). Combined EEG/eye tracking was used together with a saccade-contingent parafoveal preview manipulation to investigate neural correlates, while participants read 5-word lists. Fixation-related potentials (FRPs) showed a reduced late N1 effect (preview positivity), but this effect was modulated by the prior experience with a specific reading direction. Results replicate previous findings that valid previews facilitate visual word processing, as indicated by reduced FRP activation. Critically, the results indicate that this facilitation effect depends on experience with a given reading direction, suggesting a specific mechanism how cultural experience shapes the way people process visual information.

neuroscience↗

Is there magnocellular facilitation of early neural processes underlying visual word recognition? Evidence from masked repetition priming with ERPs

An influential theory in the field of visual object recognition proposes that fast magnocellular (M) information facilitates neural processing of spatially more fine-grained but slower parvocellular (P) information. While written words can be considered as a special type of visual objects, it is unknown whether magnocellular facilitation also plays a role in reading. We used a masked priming paradigm that has been shown to result in neural facilitation in visual word processing and tested whether these facilitating effects are mediated by the magnocellular system. In two experiments, we manipulated the influence of magnocellular and parvocellular systems on visual processing of a contextually predictable target character by contrasting high versus low spatial frequency and luminance versus color contrast, respectively. In addition, unchanged (normal) primes were included in both experiments as a manipulation check. As expected, unchanged primes elicited typical repetition effects in the N1, N250 and P3 components of the ERP in both experiments. In the experiment manipulating spatial contrast, we obtained repetition effects only for the N1 component for both M- and P-biased primes. In the luminance versus color contrast experiment, repetition effects were found in N1 and N250 for both M- and P- biased primes. Furthermore, no interactions were found between M- vs. P-biased prime types and repetition. Together these results indicate that M- and P- information contributes jointly to early neural processes underlying visual word recognition.

neuroscience↗

Genome Wide Association Scan identifies new variants associated with a cognitive predictor of dyslexia.

Developmental dyslexia (DD) is one of the most prevalent learning disorders among children and is characterized by deficits in different cognitive skills, including reading, spelling, short term memory and others. To help unravel the genetic basis of these skills, we conducted a Genome Wide Association Study (GWAS), including nine cohorts of reading-impaired and typically developing children of European ancestry, recruited across different countries (N=2,562-3,468).\n\nWe observed a genome-wide significant effect (p<1x10-8) on rapid automatized naming of letters (RANlet) for variants on 18q12.2 within MIR924HG (micro-RNA 924 host gene; p = 4.73x10-9), and a suggestive association on 8q12.3 within NKAIN3 (encoding a cation transporter; p = 2.25 x10-8). RAN represents one of the best universal predictors of reading fluency across orthographies and linkage to RAN has been previously reported within CELF4 (18q12.2), a gene highly expressed in the fetal brain which is co-expressed with NKAIN3 and predicted to be a target of MIR924. These findings suggest new candidate DD susceptibility genes and provide insights into the genetics and neurobiology of dyslexia.

genomics↗