The typical and atypical developing mind: a common model.

We present a theory of atypical development based on a developmental theory of the typical mind integrating developmental, cognitive, and psychometric theory and research. The paper comprises three parts. First, it outlines the theory of typical development. The theory postulates central cognitive mechanisms, such as relational integration, executive and inferential processes, and domain-specific processes underlying different environmental relations, such as visuospatial or quantitative relations. Cognitive development advances in cycles satisfying developmental priorities in mastering these systems, such as executive control from 2-6 years, inferential control from 7-11 years, and truth control from 12-18 years. Second, we discuss atypical development, showing how each neurodevelopmental disorder emerges from deficiencies in one or more of the processes comprising the architecture of the mind. Deficiencies in relational integration mechanisms, together with deficiencies in social understanding, yield autism spectrum disorder. Deficiencies in executive processes yield attention-deficit and hyperactivity disorder. Deficiencies in symbolic representation yield specialized learning difficulties, such as dyslexia and dyscalculia. Finally, we discuss clinical and educational implications, suggesting the importance of early diagnosis of malfunctioning in each of these dimensions and specific programs for their remediation.

Eye Movement Evidence for Simultaneous Cognitive Processing in Reading.

Measuring simultaneous processing, a reliable predictor of reading development and reading difficulties (RDs), has traditionally involved cognitive tasks that test reaction or response time, which only capture the efficiency at the output processing stage and neglect the internal stages of information processing. However, with eye-tracking methodology, we can reveal the underlying temporal and spatial processes involved in simultaneous processing and investigate whether these processes are equivalent across chronological or reading age groups. This study used eye-tracking to investigate the simultaneous processing abilities of 15 Grade 6 and 15 Grade 3 children with RDs and their chronological-age controls (15 in each Grade). The Grade 3 typical readers were used as reading-level (RL) controls for the Grade 6 RD group. Participants were required to listen to a question and then point to a picture among four competing illustrations demonstrating the spatial relationship raised in the question. Two eye movements (fixations and saccades) were recorded using the EyeLink 1000 Plus eye-tracking system. The results showed that the Grade 3 RD group produced more and longer fixations than their CA controls, indicating that the pattern of eye movements of young children with RD is typically deficient compared to that of their typically developing counterparts when processing verbal and spatial stimuli simultaneously. However, no differences were observed between the Grade 6 groups in eye movement measures. Notably, the Grade 6 RD group outperformed the RL-matched Grade 3 group, yielding significantly fewer and shorter fixations. The discussion centers on the role of the eye-tracking method as a reliable means of deciphering the simultaneous cognitive processing involved in learning.

Phonological ability and neural congruency: Phonological loop or more?

OBJECTIVE: We explored neural components in Electroencephalography (EEG) signals during a phonological processing task to assess (a) the neural origins of Baddeley's working-memory components contributing to phonological processing, (b) the unitary structure of phonological processing and (c) the neural differences between children with dyslexia (DYS) and controls (CAC). METHODS: EEG data were collected from sixty children (half with dyslexia) while performing the initial- and final- phoneme elision task. We explored a novel machine-learning-based approach to identify the neural components in EEG elicited in response to the two conditions and capture differences between DYS and CAC. RESULTS: Our method identifies two sets of phoneme-related neural congruency components capturing neural activations distinguishing DYS and CAC across conditions. CONCLUSIONS: Neural congruency components capture the underlying neural mechanisms that drive the relationship between phonological deficits and dyslexia and provide insights into the phonological loop and visual-sketchpad dimensions in Baddeley's model at the neural level. They also confirm the unitary structure of phonological awareness with EEG data. SIGNIFICANCE: Our findings provide novel insights into the neural origins of the phonological processing differences in children with dyslexia, the unitary structure of phonological awareness, and further verify Baddeley's model as a theoretical framework for phonological processing and dyslexia.

RAN-related neural-congruency: a machine learning approach toward the study of the neural underpinnings of naming speed.

Objective: Naming speed, behaviorally measured via the serial Rapid automatized naming (RAN) test, is one of the most examined underlying cognitive factors of reading development and reading difficulties (RD). However, the unconstrained-reading format of serial RAN has made it challenging for traditional EEG analysis methods to extract neural components for studying the neural underpinnings of naming speed. The present study aims to explore a novel approach to isolate neural components during the serial RAN task that are (a) informative of group differences between children with dyslexia (DYS) and chronological age controls (CAC), (b) improve the power of analysis, and (c) are suitable for deciphering the neural underpinnings of naming speed. Methods: We propose a novel machine-learning-based algorithm that extracts spatiotemporal neural components during serial RAN, termed RAN-related neural-congruency components. We demonstrate our approach on EEG and eye-tracking recordings from 60 children (30 DYS and 30 CAC), under phonologically or visually similar, and dissimilar control tasks. Results: Results reveal significant differences in the RAN-related neural-congruency components between DYS and CAC groups in all four conditions. Conclusion: Rapid automatized naming-related neural-congruency components capture the neural activity of cognitive processes associated with naming speed and are informative of group differences between children with dyslexia and typically developing children. Significance: We propose the resulting RAN-related neural-components as a methodological framework to facilitate studying the neural underpinnings of naming speed and their association with reading performance and related difficulties.

Expanding horizons of cross-linguistic research on reading: The Multilingual Eye-movement Corpus (MECO).

Scientific studies of language behavior need to grapple with a large diversity of languages in the world and, for reading, a further variability in writing systems. Yet, the ability to form meaningful theories of reading is contingent on the availability of cross-linguistic behavioral data. This paper offers new insights into aspects of reading behavior that are shared and those that vary systematically across languages through an investigation of eye-tracking data from 13 languages recorded during text reading. We begin with reporting a bibliometric analysis of eye-tracking studies showing that the current empirical base is insufficient for cross-linguistic comparisons. We respond to this empirical lacuna by presenting the Multilingual Eye-Movement Corpus (MECO), the product of an international multi-lab collaboration. We examine which behavioral indices differentiate between reading in written languages, and which measures are stable across languages. One of the findings is that readers of different languages vary considerably in their skipping rate (i.e., the likelihood of not fixating on a word even once) and that this variability is explained by cross-linguistic differences in word length distributions. In contrast, if readers do not skip a word, they tend to spend a similar average time viewing it. We outline the implications of these findings for theories of reading. We also describe prospective uses of the publicly available MECO data, and its further development plans.

Fixation-related potentials in naming speed: A combined EEG and eye-tracking study on children with dyslexia.

OBJECTIVE: We combined electroencephalography (EEG) and eye-tracking recordings to examine the underlying factors elicited during the serial Rapid-Automatized Naming (RAN) task that may differentiate between children with dyslexia (DYS) and chronological age controls (CAC). METHODS: Thirty children with DYS and 30 CAC (Mage = 9.79 years; age range 7.6 through 12.1 years) performed a set of serial RAN tasks. We extracted fixation-related potentials (FRPs) under phonologically similar (rime-confound) or visually similar (resembling lowercase letters) and dissimilar (non-confounding and discrete uppercase letters, respectively) control tasks. RESULTS: Results revealed significant differences in FRP amplitudes between DYS and CAC groups under the phonologically similar and phonologically non-confounding conditions. No differences were observed in the case of the visual conditions. Moreover, regression analysis showed that the average amplitude of the extracted components significantly predicted RAN performance. CONCLUSION: FRPs capture neural components during the serial RAN task informative of differences between DYS and CAC and establish a relationship between neurocognitive processes during serial RAN and dyslexia. SIGNIFICANCE: We suggest our approach as a methodological model for the concurrent analysis of neurophysiological and eye-gaze data to decipher the role of RAN in reading.

Dyslexia in a consistent orthography: Evidence from reading-level match design.

Studies in consistent orthographies using reading-level (RL) match design have produced conflicting results, possibly because of problems with general ability and RL matching in many studies. We matched the participants on both verbal and nonverbal ability and on reading tasks with no ceiling effects and compared the performance of Grades 4 and 6 Greek-speaking children with dyslexia to those of chronological age (CA) and RL matched control groups across a variety of tasks associated with dyslexia (phonological awareness, rapid naming, phonological memory, and orthographic processing). The results showed that although both Grade 4 and Grade 6 dyslexics performed poorer than the CA groups in most tasks, they did not perform poorer than the RL group in any of the tasks included. We conclude with a discussion of the theoretical ramifications of the results and the appropriateness of the RL match design in studying dyslexia in consistent orthographies.

Specific Language Impairment and Reading Disability: Categorical Distinction or Continuum?

Specific language impairment (SLI) and reading disability (RD) are familial, moderately heritable comorbid developmental disorders. The key deficit of SLI is oral language, whereas children with RD exhibit impairment in learning to read. The present study examines the possible co-occurrence of RD and SLI and the nature of this co-occurrence at a linguistic and a cognitive level in an orthographically consistent language. Four groups of children participated in the study: an RD group ( n = 10), an SLI group ( n = 13), a possible comorbid group ( n = 9), and a control-no deficit group ( n = 20). Analysis showed that all three clinical groups in our sample performed similarly in phonological awareness and naming-speed tasks. However, significant group differences were observed in orthographic processing, reading, semantics, and phonological memory measures, thus supporting the view that SLI and RD are distinct disorders. Results are in line with previous findings indicating that SLI and RD share common characteristics, although the two conditions are manifested with different symptoms.

The Structure of Speed of Processing Across Cultures.

We examined whether a general processing factor emerges when using response times for cognitive processing tasks and whether such a factor is valid across three different cultural groups (Chinese, Canadian, and Greek). Three hundred twenty university students from Canada (n = 115), China (n = 110), and Cyprus (n = 95) were assessed on an adaptation of the Das-Naglieri Cognitive Assessment System (D-N CAS; Naglieri & Das, 1997). Three alternative models were contrasted: a distinct abilities processing speed model (Model 1) that is dictated by the latent four cognitive factors of planning, attention, simultaneous and successive (PASS) processing, a unitary ability processing speed model (Model 2) that is dictated by the response time nature of all measures, and a bifactor model (Model 3) which included the latent scores of Models 1 and 2 and served as the full model. Results of structural equation modeling showed that (a) the model representing processing speed as a collection of four cognitive processes rather than a unitary processing speed factor was the most parsimonious, and (b) the loadings of the obtained factors were invariant across the three cultural groups. These findings enhance our understanding of the nature of speed of processing across diverse cultures and suggest that even when cognitive processes (i.e., PASS) are operationalized with response time measures, the processing component dominates speed.

Your Brain on the Movies: A Computational Approach for Predicting Box-office Performance from Viewer's Brain Responses to Movie Trailers.

The ability to anticipate the population-wide response of a target audience to a new movie or TV series, before its release, is critical to the film industry. Equally important is the ability to understand the underlying factors that drive or characterize viewer's decision to watch a movie. Traditional approaches (which involve pilot test-screenings, questionnaires, and focus groups) have reached a plateau in their ability to predict the population-wide responses to new movies. In this study, we develop a novel computational approach for extracting neurophysiological electroencephalography (EEG) and eye-gaze based metrics to predict the population-wide behavior of movie goers. We further, explore the connection of the derived metrics to the underlying cognitive processes that might drive moviegoers' decision to watch a movie. Towards that, we recorded neural activity-through the use of EEG-and eye-gaze activity from a group of naive individuals while watching movie trailers of pre-selected movies for which the population-wide preference is captured by the movie's market performance (i.e., box-office ticket sales in the US). Our findings show that the neural based metrics, derived using the proposed methodology, carry predictive information about the broader audience decisions to watch a movie, above and beyond traditional methods. In particular, neural metrics are shown to predict up to 72% of the variance of the films' performance at their premiere and up to 67% of the variance at following weekends; which corresponds to a 23-fold increase in prediction accuracy compared to current neurophysiological or traditional methods. We discuss our findings in the context of existing literature and hypothesize on the possible connection of the derived neurophysiological metrics to cognitive states of focused attention, the encoding of long-term memory, and the synchronization of different components of the brain's rewards network. Beyond the practical implication in predicting and understanding the behavior of moviegoers, the proposed approach can facilitate the use of video stimuli in neuroscience research; such as the study of individual differences in attention-deficit disorders, and the study of desensitization to media violence.

How Is RAN Related to Reading Fluency? A Comprehensive Examination of the Prominent Theoretical Accounts.

We examined the prominent theoretical explanations of the RAN-reading relationship in a relatively transparent language (Greek) in a sample of children (n = 286) followed from Grade 1 to Grade 2. Specifically, we tested the fit of eight different models, as defined by the type of reading performance predicted (oral vs. silent word reading fluency), the type of RAN tasks (non-alphanumeric vs. alphanumeric), and the RAN effects (direct vs. indirect). Working memory, attention, processing speed, and motor skills were used as "common cause" variables predicting both RAN and reading fluency and phonological awareness and orthographic processing were used as mediators of RAN's effects on reading fluency. The findings of both concurrent and longitudinal analyses indicated that RAN is a unique predictor of oral reading fluency, but not silent reading fluency. Using alphanumeric or non-alphanumeric RAN did not particularly affect the RAN-reading relationship. Both phonological awareness and orthographic processing partly mediated RAN's effects on reading fluency. Theoretical implications of these findings are discussed.

Why is rapid automatized naming related to reading?

The objective of this study was to examine why rapid automatized naming (RAN) is related to reading by manipulating processes involved at the input, processing, and output stages of its production. In total, 65 children in Grade 2 and 65 in Grade 6 were assessed on serial and discrete RAN (Digits and Objects), Cancellation, RAN Yes/No, and oral and silent reading fluency. The results of regression analyses indicated that RAN is related to reading because both involve serial processing and oral production of the names of the stimuli.

Low-level deficits in beat perception: neither necessary nor sufficient for explaining developmental dyslexia in a consistent orthography.

This article reports two different studies examining the theoretical account of low-level deficits in beat perception as an alternative explanation of developmental dyslexia in Greek, an orthographically consistent language. Study I examined the relationship of amplitude rise time and frequency discrimination with measures of phonological processing, working memory, and reading fluency in a large unselected sample of Grade 4 children. Study II examined the presence of beat perception deficits in groups of Grade 2, 4, and 6 children with dyslexia and their chronological age controls. The results provided no evidence to support meaningful associations between beat perception tasks and reading or the theoretical account of beat perception deficits as a sufficient explanation or contributing factor to dyslexia. Implications on the importance of auditory processing in reading in orthographically consistent languages are discussed.

Are auditory and visual processing deficits related to developmental dyslexia?

The purpose of this study was to examine if children with dyslexia learning to read a consistent orthography (Greek) experience auditory and visual processing deficits and if these deficits are associated with phonological awareness, rapid naming speed and orthographic processing. We administered measures of general cognitive ability, phonological awareness, orthographic processing, short-term memory, rapid automatized naming, auditory and visual processing, and reading fluency to 21 Grade 6 children with dyslexia, 21 chronological age-matched controls and 20 Grade 3 reading age-matched controls. The results indicated that the children with dyslexia did not experience auditory processing deficits, but about half of them showed visual processing deficits. Both orthographic processing and rapid automatized naming deficits were associated with dyslexia in our sample, but it is less clear that they were associated with visual processing deficits.

Rapid naming speed components and reading development in a consistent orthography.

We examined how rapid automatized naming (RAN) components-articulation time and pause time-predict word and text reading fluency in a consistent orthography (Greek). In total, 68 children were followed from Grade 2 to Grade 6 and were assessed three times on RAN (Digits and Objects), phonological awareness, orthographic processing, speed of processing, and reading fluency. Both RAN components were strongly related to reading fluency and, with few exceptions, accounted for unique variance over and above the contribution of speed of processing, phonological awareness, and orthographic processing. The amount of predictive variance shared between the components and the cognitive processing skills varied across time. The implications of these findings for the RAN-reading relationship are discussed.

Auditory temporal processing and dyslexia in an orthographically consistent language.

We examined two hypotheses relating auditory processing to dyslexia in Greek, an orthographically consistent language. Study I examined the "P-center" or "beat detection" hypothesis (Goswami et al., 2002) in a sample of Grade 6 dyslexics, Grade 6 chronological age (CA) controls, and Grade 4 reading age (RA) controls. Study II examined the "temporal processing," or "rapid auditory processing" hypothesis (Tallal, 1980) in a sample of Grade 7 dyslexics, CA controls, and in two groups of CA matched children with low frequency discrimination or low tone sequencing performance. Both studies indicate that (a) as a group, dyslexic children did not perform significantly worse on auditory processing measures than the control groups; (b) measures of auditory processing mostly did not account for unique amount of variance in phonological processing, reading, or spelling; and (c) at an individual level of analysis, some of the dyslexic children experienced auditory temporal processing deficits. Implications on the importance of auditory processing in reading in orthographically consistent languages are discussed.

Investigating the double-deficit hypothesis in Greek: findings from a longitudinal study.

This study examined longitudinally the double-deficit hypothesis in Greek, an orthographically consistent language, following a group of children from kindergarten to Grade 2. Four groups were formed on the basis of two composite scores of phonological and naming-speed criterion measures: a double-deficit group (DD; n = 17), a phonological deficit group (PD; n = 33), a naming deficit group (ND; n = 33), and a control group exhibiting no deficits (CnD; n = 159). The four groups were identified in Grade 1, and they were compared retrospectively in kindergarten only on the criterion measures, and in Grades 1 and 2 on measures of word-reading fluency and accuracy, orthographic processing, and passage comprehension. The effects of verbal and nonverbal ability, age, gender, and parental education were controlled among the groups. Results showed that the DD group exhibited greater dysfunction in reading and orthographic processing compared to the single-deficit and CnD groups. Also, although the three deficit groups were not easily differentiated in kindergarten, their differences were maximized in Grade 1 and retained in Grade 2. The type and severity of reading deficits found in the ND group were mostly associated with naming speed at both the word- and text-reading levels, deficits that persisted across development. The PD group showed mostly deficient orthographic and poor decoding skills that improved across development. Implications of the findings for the double-deficit hypothesis in languages with transparent orthographies are discussed.

Evidence of poor planning in children with attention deficits.

This study examined the planning performance of children with attention deficits, and also investigated the possible interactions between inattention and anxiety in the performance of executive function tasks. A group of 98 children (grades 4 and 6), derived from an initial group of 550, were assigned to an attention difficulties group (AD) and a control group (n = 49 each) based on their scores on a variety of cognitive attention measures and teacher scales of attention and hyperactivity. The two groups were matched on age, gender, parental education, non-verbal and verbal ability. They were compared on Crack-the-Code (C-t-C) action-planning task, embedded and ambiguous figures and Theory of Mind tasks. Analyses indicated that the failure of AD children on cognitive performance measures is linked to planning impairments. The co-occurrence of anxiety, in turn, did not interact with inattention to affect planning performance differentially. Implications of these findings for the current discussion about the cognitive and emotional processes underlying impaired performance among children with attention deficits on executive control tasks are discussed.