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Specific word reading difficulty, commonly termed ‘developmental dyslexia’, refers to the low end of the word reading skill distribution but is frequently considered to be a neurodevelopmental disorder. This term implies that brain development is thought to be disrupted, resulting in an abnormal and dysfunctional brain. We take issue with this view, pointing out that there is no evidence of any obvious neurological abnormality in the vast majority of cases of word reading difficulty cases. The available relevant evidence from neuroimaging studies consists almost entirely of correlational and group-differences studies. However, differences in brains are certain to exist whenever differences in behavior exist, including differences in ability and performance. Therefore, findings of brain differences do not constitute evidence for abnormality; rather, they simply document the neural substrate of the behavioral differences. We suggest that dyslexia is best viewed as one of many expressions of ordinary ubiquitous individual differences in normal developmental outcomes. Thus, terms such as “dysfunctional” or “abnormal” are not justified when referring to the brains of persons with dyslexia.

•A novel methodology to enhance the standard design matrix is proposed within the GLM framework for task-related fMRI data analysis.•The proposed methodology offers an enhanced potential: (a) It efficiently copes with uncertainties in modeling the hemodynamic response. (b) It accommodates unmodeled brain-induced sources beyond the task-related ones, as well as potential interfering scanner-induced artifacts, uncorrected head-motion residuals, and other unmodeled physiological signals. (c) It integrates external knowledge regarding the sparsity percentage associated with both the experimental design and brain atlases without the necessity of an explicit spatial template.•Results show the new approach is more sensitive to detecting significant activity than using the standard design matrix.•Results evidence the new approach provides more anatomically reliable activation clusters than using the standard design matrix.•A new toolbox extension for SPM with the proposed methodology was developed. In this paper, we introduce a novel methodology for the analysis of task-related fMRI data. In particular, we propose an alternative way for constructing the design matrix, based on the newly suggested Information-Assisted Dictionary Learning (IADL) method. This technique offers an enhanced potential, within the conventional GLM framework, (a) to efficiently cope with uncertainties in the modeling of the hemodynamic response function, (b) to accommodate unmodeled brain-induced sources, beyond the task-related ones, as well as potential interfering scanner-induced artifacts, uncorrected head-motion residuals and other unmodeled physiological signals, and (c) to integrate external knowledge regarding the natural sparsity of the brain activity that is associated with both the experimental design and brain atlases. The capabilities of the proposed methodology are evaluated via a realistic synthetic fMRI-like dataset, and demonstrated using a test case of a challenging fMRI study, which verifies that the proposed approach produces substantially more consistent results compared to the standard design matrix method. A toolbox extension for SPM is also provided, to facilitate the use and reproducibility of the proposed methodology.

Research into second language (L2) reading is an exponentially growing field. Yet, it still has a relatively short supply of comparable, ecologically valid data from readers representing a variety of first languages (L1). This article addresses this need by presenting a new data resource called MECO L2 (Multilingual Eye Movements Corpus), a rich behavioral eye-tracking record of text reading in English as an L2 among 543 university student speakers of 12 different L1s. MECO L2 includes a test battery of component skills of reading and allows for a comparison of the participants’ reading performance in their L1 and L2. This data resource enables innovative large-scale cross-sample analyses of predictors of L2 reading fluency and comprehension. We first introduce the design and structure of the MECO L2 resource, along with reliability estimates and basic descriptive analyses. Then, we illustrate the utility of MECO L2 by quantifying contributions of four sources to variability in L2 reading proficiency proposed in prior literature: reading fluency and comprehension in L1, proficiency in L2 component skills of reading, extralinguistic factors, and the L1 of the readers. Major findings included (a) a fundamental contrast between the determinants of L2 reading fluency versus comprehension accuracy, and (b) high within-participant consistency in the real-time strategy of reading in L1 and L2. We conclude by reviewing the implications of these findings to theories of L2 acquisition and outline further directions in which the new data resource may support L2 reading research.

The serial advantage, defined as the gain in naming rate in the serial over the discrete task of the same content, was examined between grades and types of content in English and Greek. 720 English- and Greek-speaking children from Grades 1, 3, and 5 were tested in rapid naming and reading tasks of different content, including digits, objects, dice, number words, and words. Each type of content was presented in two presentation formats: multiple stimulus displays (i.e., serial naming) and isolated stimulus displays (i.e., discrete naming). Serial tasks yielded faster naming rates—irrespective of task content—in both languages. However, content-specific characteristics influenced the trajectory of the serial advantage between grades. Improvement in the serial advantage between grades was found to be greatest for word reading, which started off similar to object naming in Grade 1, but ended up similar to digit or dice naming by Grade 5. In addition, growth in serial advantage was found to be associated with growth in discrete naming rate only in grade level analysis. For individuals, greater serial advantage was found to rely on processing skills specific to serial naming rather than on differences in the rate of naming isolated items. Our findings suggest that group level findings may not generalize to individuals, and although practice and familiarity with the content on the naming/reading task may impact the development of serial advantage, isolated item identification processes contribute little to individual differences in the gain in serial naming rates.

We recently pointed out that there is no evidence to support the commonly held view that there is something wrong with the brains of children who have great difficulty learning to read. In response, it was argued that dyslexia should be considered to be a neurodevelopmental disorder because of its potential to adversely affect quality of life, and because there are differences between the brains of people with different levels of reading skill. We agree with these two points, but they are irrelevant to the issue in question, because neither establishes the critical notion of disrupted neurodevelopment; that is, a brain fault. Differences between groups do not imply that any individuals are abnormal, and calling a brain improperly developed on the basis of cultural issues has absurd implications. Even calling brains atypical is unfounded because reference to typicality hinges on knowledge of the relevant distributions, which is currently lacking. Moreover, there is at present no obvious role for neurology- or neuroscience-based input for the critical issue of the assessment and remediation of the reading difficulties themselves. We reiterate our conclusion that there is, at the moment, no credible foundation to support the claim that dyslexia is a neurodevelopmental disorder.

The ‘rapid temporal processing’ and the ‘temporal sampling framework’ hypotheses have been proposed to account for the deficits in language and literacy development seen in specific language impairment and dyslexia. This paper reviews these hypotheses and concludes that the proposed causal chains between the presumed auditory processing deficits and the observed behavioural manifestation of the disorders are vague and not well established empirically. Several problems and limitations are identified. Most data concern correlations between distantly related tasks, and there is considerable heterogeneity and variability in performance as well as concerns about reliability and validity. Little attention is paid to the distinction between ostensibly perceptual and metalinguistic tasks or between implicit and explicit modes of performance, yet measures are assumed to be pure indicators of underlying processes or representations. The possibility that diagnostic categories do not refer to causally and behaviourally homogeneous groups needs to be taken seriously, taking into account genetic and neurodevelopmental studies to construct multiple-risk models. To make progress in the field, cognitive models of each task must be specified, including performance domains that are predicted to be deficient versus intact, testing multiple indicators of latent constructs and demonstrating construct reliability and validity.

CheckVocal is a Windows application that facilitates checking the accuracy and response time of recorded vocal responses in naming and other experimental tasks using the DMDX display and response collection software. CheckVocal handles all keeping-track and presents each recorded response audiovisually (as waveform, spectrogram, and sound played out) along with the correspondingprinted correct response andregistered responsetime. The user simply decides whether the response was correct, wrong, or missing, with a single mouse click advancing to the next response. Response ti me correction can be done manually or automatically (retriggering by apower threshold). Data safety and integrity is ensured by cross-checking and status saving, so t hat interruptedsessions can be resumed later. CheckVocal is freely available to the DMDX community via a dedicated Web page.

Speech comprehension depends on the integrity of both the spectral content and temporal envelope of the speech signal. Although neural processing underlying spectral analysis has been intensively studied, less is known about the processing of temporal information. Most of speech information conveyed by the temporal envelope is confined to frequencies below 16 Hz, frequencies that roughly match spontaneous and evoked modulation rates of primary auditory cortex neurons. To test the importance of cortical modulation rates for speech processing, we manipulated the frequency of the temporal envelope of speech sentences and tested the effect on both speech comprehension and cortical activity. Magnetoencephalographic signals from the auditory cortices of human subjects were recorded while they were performing a speech comprehension task. The test sentences used in this task were compressed in time. Speech comprehension was degraded when sentence stimuli were presented in more rapid (more compressed) forms. We found that the average comprehension level, at each compression, correlated with (i) the similarity between the frequencies of the temporal envelopes of the stimulus and the subject's cortical activity (\"stimulus-cortex frequency-matching\") and (ii) the phase-locking (PL) between the two temporal envelopes (\"stimulus-cortex PL\"). Of these two correlates, PL was significantly more indicative for single-trial success. Our results suggest that the match between the speech rate and the a priori modulation capacities of the auditory cortex is a prerequisite for comprehension. However, this is not sufficient: stimulus-cortex PL should be achieved during actual sentence presentation.

A broad battery of psychoacoustic measures and standard measures of reading and spelling were applied to 102 adults. The test group included individuals with a childhood history of reading difficulties and controls with no reported reading difficulties. Reading scores were variable in both groups. Poor auditory processing abilities were recorded in poor readers; particular difficulties were posed by tasks requiring spectral distinctions, the simplest of which was pure tone frequency discrimination. In absolute terms, the greatest deficits were recorded in tasks in which stimuli were presented in brief forms and in rapid succession. Auditory processing abilities accounted for more than 50% of the reading score variance in the control group, but their correlation with reading scores was lower in the group with childhood histories of reading difficulties. The additional variability in the latter group resulted largely from the prevalence of reading-compensated poor psychoacoustic performers, whose short-term word memory was also typically poor. Taken together, these findings support a link between impaired auditory resolution and poor reading. Psychoacoustic difficulties are largely retained through adulthood and may be the source of the retained reading difficulties.