Cognitive control beyond single-item tasks: Insights from pupillometry, gaze, and behavioral measures.

Cognitive control has been typically examined using single-item tasks. This has implications for the generalizability of theories of control implementation. Previous studies have revealed that different control demands are posed by tasks depending on whether they present stimuli individually (i.e., single-item) or simultaneously in array format (i.e., multi-item). In the present study, we tracked within-task performance in single-item and multi-item Stroop tasks using simultaneous pupillometry, gaze, and behavioral response measures, aiming to explore the implications of format differences for cognitive control. The results indicated within-task performance decline in the multi-item version of the Stroop task, accompanied by pupil constriction and dwell time increase, in both the incongruent and the neutral condition. In contrast, no performance decline or dwell time increase was observed in the course of the single-item version of the task. We interpret these findings in terms of capacity constraints on cognitive control, with implications for cognitive control research, and highlight the need for better understanding of the cognitive demands of multi-item tasks. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Early rapid naming longitudinally predicts shared variance in reading and arithmetic fluency.

A number of cognitive factors have been suggested to underlie development in reading and arithmetic skills. Although the two domains are strongly linked, only a few studies have investigated the processes that are shared between them during the early school years. Rapid automatized naming (RAN) has been identified as a strong predictor of a common fluency factor in reading and arithmetic. In the current study with 232 Norwegian children, we examined how RAN in preschool and Grade 1 relates to the shared and nonshared variance in arithmetic fluency and reading fluency in Grade 3. Furthermore, we examined whether related processing skills (phoneme awareness, working memory, speed of processing, and symbol knowledge) can account for the relationship between RAN and shared fluency-or if they predict variance that is unique to each domain. Our results show that RAN in both preschool and Grade 1 is a strong predictor of shared variance between reading fluency and arithmetic fluency measured several years later, whereas other predictors mainly relate to the nonshared parts of variance in the fluency outcomes. That is, control variables with the theoretical potential to explain some of RAN's relation to the overlap between reading and arithmetic fluency do not in fact account for this relationship. Our findings provide a starting point for future investigations of the mechanisms of rapid naming.

Serial and discrete naming and reading in Chinese first graders: Testing predictions from the cascaded processing hypothesis.

Recent studies have suggested that-beyond automaticity and prosody-reading fluency involves parallel processing of adjacent items presented in a sequence, termed "cascaded processing." To date, most studies examining cascaded processing have been conducted in alphabetic orthographies. Thus, the purpose of this study was to examine the cascaded processing hypothesis in Chinese. A total of 119 Grade 1 Chinese children (61 boys and 58 girls; Mage = 7.30 years, SD = 0.31) were assessed on serial and discrete naming of digits as well as on serial and discrete naming of high-frequency one- and two-character words and low-frequency one-character words presented with pinyin. Results of hierarchical regression analyses showed, first, that serial digit naming was a unique predictor of discrete naming of low-frequency one-character words and two-character words, but not of high-frequency one-character words. Second, serial digit naming was a unique predictor of reading of high-frequency one- and two-character word reading after controlling for discrete word reading. These findings suggest that Chinese first graders process high-frequency characters holistically (similar to simple digits), which then facilitates parallel processing of multiple stimuli when they are presented in a sequence.

Immediate and sustained effects of verbal labels for newly-learned categories.

Labels for the categories have been found to facilitate learning by boosting accuracy. According to the label-feedback hypothesis, this facilitation is due to a mechanism selectively sensitising perceptual dimensions. To further investigate the label-facilitation phenomenon, one group of participants in our study learned both named and hard-to-name artificial categories, in a novel, within-subjects design. Another group of participants was administered a-highly similar-paired-associate task purportedly not involving sensitization of dimensions. Results showed that labels boosted accuracy during learning, but only when learning to categorise-not when learning to associate. The label-feedback hypothesis posits that labels exert an influence also after new categories have been learned. To test for sustained effects of labels, we administered a post-learning visual discrimination task while monitoring participants' eye movements and analysing dwell time on the trained shapes. There was some indication of sustained effects of labels for newly-learned categories, but there was no effect following learning to associate. Our results suggest that labels for newly learned categories have immediate effects during learning and that the effects of labels may also be sustained during post-learning processing.

Conflict monitoring or multi-tasking? Tracking within-task performance in single-item and multi-item Stroop tasks.

Cognitive control is applied in situations that require overriding a habitual and automatic response. The conflict monitoring hypothesis and the Expected Value of Control (EVC) theory as its extension posit a control system responsible for detecting conflicting occasions and adapting to them dynamically within a task. Here we evaluate this prediction in two versions of one of the most popular tasks in cognitive control, namely the Stroop task. We hypothesized that nearby-items interference combines with task interference in the multi-item version effectively turning it into a multi-task that may challenge cognitive control. Adopting an alternative methodology tracking within-task performance, we compared the classical multi-item version of the Stroop task and its single-item counterpart in adults and children. The results revealed a within-task performance decline only in the multi-item version of the task, in both incongruent and neutral conditions, modulated by the presumed maturity of the control system. These findings suggest capacity constraints in control implementation and allocation under conditions requiring parallel execution of multiple cognitive tasks. Task complexity and demands seem to modulate effects on performance. We discuss implications for cognitive control as well as substantial concerns regarding the calculation and use of indices of interference based on the commonly used multi-item version of the Stroop task.

Cascaded processing in naming and reading: Evidence from Chinese and Korean.

Previous studies have shown that the ability to simultaneously process multiple items when these appear in serial format (called "cascaded" processing) is an important element of reading fluency. However, most evidence in support of cascaded processing comes from studies conducted in European orthographies. Thus, the purpose of the current study was to examine whether the same findings generalize to nonlinear and nonalphabetic orthographies (i.e., Korean and Chinese). Serial and discrete naming of digits and objects were measured in a sample of 610 Chinese and Korean children from Grades 1, 3, 5, and 6. Children were also assessed on discrete word reading and on word- and text-reading fluency. Results of hierarchical regression analysis showed that discrete naming was the main predictor of discrete word reading in both languages as early as Grade 1. Serial digit naming was the main predictor of word-reading fluency across grades and languages. Finally, serial object naming made a unique contribution to word- and text-reading fluency in Chinese upper grades. Taken together, these findings suggest that, beyond accurate and fast word recognition, there is a universal multi-item (or cascaded) processing skill involved in serial naming and reading fluency.

Task format modulates the relationship between reading ability and Stroop interference.

Previous research has shown that Stroop interference and reading ability are negatively related, with higher reading skills associated with less interference. A direct link between interference and the speed of inhibition of the task-irrelevant dimension (i.e., word) has been proposed to explain this relationship. If that were the case then it should apply regardless of the format of the Stroop task, that is, whether stimuli are presented simultaneously (multi-item version) or individually (single-item version). Here we examine data from six experiments using single-item and multi-item Stroop tasks and their relationship to reading measures. Our results indicate that reading performance is primarily related to the multi-item version of the Stroop task and not to the single-item version. These findings question the direct link between inhibition and interference as an interpretation of the reading-interference relationship. We argue that cascaded processing of successive items, and the ability to monitor and control this process, is the cognitive mechanism regulating the relationship between reading and interference. Therefore, we propose that the link between Stroop interference and reading is indirect, and their relationship is determined by the efficiency in temporally overlapping processing of adjacent items. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

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.

Lexicality effects on orthographic learning in beginning and advanced readers of Dutch: An eye-tracking study.

Orthographic learning is the topic of many recent studies about reading, but much is still unknown about conditions that affect orthographic learning and their influence on reading fluency development over time. This study investigated lexicality effects on orthographic learning in beginning and relatively advanced readers of Dutch. Eye movements of 131 children in Grades 2 and 5 were monitored during an orthographic learning task. Children read sentences containing pseudowords or low-frequency real words that varied in number of exposures. We examined both offline learning outcomes (i.e., orthographic choice and spelling dictation) of target items and online gaze durations on target words. The results showed general effects of exposure, lexicality, and reading-skill level. Also, a two-way interaction was found between the number of exposures and lexicality when detailed orthographic representations were required, consistent with a larger overall effect of exposure on learning the spellings of pseudowords. Moreover, lexicality and reading-skill level were found to affect the learning rate across exposures based on a decrease in gaze durations, indicating a larger learning effect for pseudowords in Grade 5 children. Yet, further interactions between exposure and reading-skill level were not present, indicating largely similar learning curves for beginning and advanced readers. We concluded that the reading system of more advanced readers may cope somewhat better with words varying in lexicality, but is not more efficient than that of beginning readers in building up orthographic knowledge of specific words across repeated exposures.

Asymmetric Morphological Priming Among Inflected and Derived Verbs and Nouns in Greek.

The present study examined differences between inflectional and derivational morphology using Greek nouns and verbs with masked priming (with both short and long stimulus onset asynchrony) and long-lag priming. A lexical decision task to inflected noun and verb targets was used to test whether their processing is differentially facilitated by prior presentation of their stem in words of the same grammatical class (inflectional morphology) or of a different grammatical class (derivational morphology). Differences in semantics, syntactic information, and morphological complexity between inflected and derived word pairs (both nouns and verbs) were minimized by unusually tight control of stimuli as permitted by Greek morphology. Results showed that morphological relations affected processing of morphologically complex Greek words (nouns and verbs) across prime durations (50-250ms) as well as when items intervened between primes and targets. In two of the four experiments (Experiments 1 and 3), inflectionally related primes produced significantly greater effects than derivationally related primes suggesting differences in processing inflectional versus derivational morphological relations, which may disappear when processing is less dependent on semantic effects (Experiment 4). Priming effects differed for verb vs. noun targets with long SOA priming (Experiment 3), consistent with processing differences between complex words of different grammatical class (nouns and verbs) when semantic effects are maximized. Taken together, results demonstrate that inflectional and derivational relations differentially affect processing complex words of different grammatical class (nouns and verbs). This finding indicates that distinctions of morphological relation (inflectional vs. derivational) are not of the same kind as distinctions of grammatical class (nouns vs. verbs). Asymmetric differences among inflected and derived verbs and nouns seem to depend on semantic effects and/or processing demands modulating priming effects very early in lexical processing of morphologically complex written words, consistent with models of lexical processing positing early access to morphological structure and early influence of semantics.

Enhanced design matrix for task-related fMRI data analysis.

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.

Lexical stress representation in spoken word recognition.

According to a popular model of speech production, stress is underspecified in the lexicon, that is, it is specified only for words with stress patterns other than the default, termed the "default metrics" assumption. Alternatively, stress may be fully specified in the lexicon as part of every lexical representation. In the current study the two accounts are tested in the perceptual domain using behavioral and eye-tracking data in Greek. In a first experiment, cross-modal fragment priming was used in a lexical-decision task. According to default metrics, priming should occur for targets with antepenultimate- or final-syllable stress but not for targets with the default penultimate-syllable stress. The same word pairs were used in two subsequent visual world experiments. Default metrics predict an asymmetric pattern of results, namely that incoming spoken words with the default stress pattern should inhibit the activation of lexical representations with nondefault stress, whereas the converse should not be observed; that is, spoken words with nondefault stress should not inhibit representations of words with the default stress. None of the results provided support for the idea of default metrics, leading to alternative conceptualizations regarding the representation of stress. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Prevalence of spelling errors affects reading behavior across languages.

This cross-linguistic study investigated the impact of spelling errors on reading behavior in five languages (Chinese, English, Finnish, Greek, and Hebrew). Learning theories predict that correct and incorrect spelling alternatives (e.g., "tomorrow" and "tommorrow") provide competing cues to the sound and meaning of a word: The closer the alternatives are to each other in their frequency of occurrence, the more uncertain the reader is regarding the spelling of that word. An information-theoretic measure of entropy was used as an index of uncertainty. Based on theories of learning, we predicted that higher entropy would lead to slower recognition of words even when they are spelled correctly. This prediction was confirmed in eye-tracking sentence-reading experiments in five languages widely variable in their writing systems' phonology and morphology. Moreover, in each language, we observed a characteristic Entropy × Frequency interaction; arguably, its functional shape varied as a function of the orthographic transparency of a given written language. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Word- and Text-Level Processes Contributing to Fluent Reading of Word Lists and Sentences.

In this study, we investigated how word- and text-level processes contribute to different types of reading fluency measures. We aimed to increase our understanding of the underlying processes necessary for fluent reading. The sample included 73 Dutch Grade 3 children, who were assessed on serial word reading rate (familiar words), word-list reading fluency (increasingly difficult words), and sentence reading fluency. Word-level processes were individual word recognition speed (discrete word reading) and sequential processing efficiency (serial digit naming). Text-level processes were receptive vocabulary and syntactic skills. The results showed that word- and text-level processes combined accounted for a comparable amount of variance in all fluency outcomes. Both word-level processes were moderate predictors of all fluency outcomes. However, vocabulary only moderately predicted sentence reading fluency, and syntactic skills merely contributed to sentence reading fluency indirectly through vocabulary. The findings indicate that sequential processing efficiency has a crucial role in reading fluency across various measures besides individual word recognition speed. Additionally, text-level processes come into play when complexity and context availability of fluency measures increases, but the exact timing requires further study. Findings are discussed in terms of future directions and their possible value for diagnostic assessment and intervention of reading difficulties.

Dyslexia: Still Not a Neurodevelopmental Disorder.

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.

Evolving Concepts of Dyslexia and Their Implications for Research and Remediation.

Aspects of dyslexia definitions are framed as a contrast between the past and the future, focusing on implications for research and remedial education, highlighting assumptions that bias or limit research or clinical practice. A crucial development is evident in understanding dyslexia, moving from its conceptualization as a discrete identifiable condition toward the realization of continuity with the general population with no clear boundaries and no qualitative differences. This conceptual evolution amounts to a transition from considering dyslexia to be some entity that causes poor reading toward considering the term dyslexia to simply label poor reading performance. This renders obsolete any searches for abnormalities and directs efforts toward understanding reading skill as a multifaceted domain following a complex multifactorial developmental course.

Using Serial and Discrete Digit Naming to Unravel Word Reading Processes.

During reading acquisition, word recognition is assumed to undergo a developmental shift from slow serial/sublexical processing of letter strings to fast parallel processing of whole word forms. This shift has been proposed to be detected by examining the size of the relationship between serial- and discrete-trial versions of word reading and rapid naming tasks. Specifically, a strong association between serial naming of symbols and single word reading suggests that words are processed serially, whereas a strong association between discrete naming of symbols and single word reading suggests that words are processed in parallel as wholes. In this study, 429 Grade 1, 3, and 5 English-speaking Canadian children were tested on serial and discrete digit naming and word reading. Across grades, single word reading was more strongly associated with discrete naming than with serial naming of digits, indicating that short high-frequency words are processed as whole units early in the development of reading ability in English. In contrast, serial naming was not a unique predictor of single word reading across grades, suggesting that within-word sequential processing was not required for the successful recognition for this set of words. Factor mixture analysis revealed that our participants could be clustered into two classes, namely beginning and more advanced readers. Serial naming uniquely predicted single word reading only among the first class of readers, indicating that novice readers rely on a serial strategy to decode words. Yet, a considerable proportion of Grade 1 students were assigned to the second class, evidently being able to process short high-frequency words as unitized symbols. We consider these findings together with those from previous studies to challenge the hypothesis of a binary distinction between serial/sublexical and parallel/lexical processing in word reading. We argue instead that sequential processing in word reading operates on a continuum, depending on the level of reading proficiency, the degree of orthographic transparency, and word-specific characteristics.

Is Dyslexia a Brain Disorder?

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.

Tracking the effects of dyslexia in reading and spelling development: A longitudinal study of Greek readers.

In this study, we followed Greek children with and without dyslexia for 18 months, assessing them twice on a battery of phonological, reading, and spelling tasks, aiming to document the relative progress achieved and to uncover any specific effects of dyslexia in the development of reading and spelling beyond the longitudinal associations among variables that are observed in typical readers. A wide-ranging match was achieved between the dyslexic group and the younger reading-matched comparison group, enabling longitudinal comparisons on essentially identical initial performance profiles. Group differences were found in the development of tasks relying on phonological processing skill, such as phoneme deletion in pseudowords, pseudoword reading accuracy and time, as well as in graphemic spelling accuracy. The results confirm findings from cross-sectional studies of reading difficulty in the relatively transparent Greek orthography and are consistent with a phonological processing deficit underlying and reciprocally interacting with underdevelopment of reading and spelling skills in the impaired population.

Preschool Phonological and Morphological Awareness As Longitudinal Predictors of Early Reading and Spelling Development in Greek.

Different language skills are considered fundamental for successful reading and spelling acquisition. Extensive evidence has highlighted the central role of phonological awareness in early literacy experiences. However, many orthographic systems also require the contribution of morphological awareness. The goal of this study was to examine the morphological and phonological awareness skills of preschool children as longitudinal predictors of reading and spelling ability by the end of first grade, controlling for the effects of receptive and expressive vocabulary skills. At Time 1 preschool children from kindergartens in the Greek regions of Attika, Crete, Macedonia, and Thessaly were assessed on tasks tapping receptive and expressive vocabulary, phonological awareness (syllable and phoneme), and morphological awareness (inflectional and derivational). Tasks were administered through an Android application for mobile devices (tablets) featuring automatic application of ceiling rules. At Time 2 one year later the same children attending first grade were assessed on measures of word and pseudoword reading, text reading fluency, text reading comprehension, and spelling. Complete data from 104 children are available. Hierarchical linear regression and commonality analyses were conducted for each outcome variable. Reading accuracy for both words and pseudowords was predicted not only by phonological awareness, as expected, but also by morphological awareness, suggesting that understanding the functional role of word parts supports the developing phonology-orthography mappings. However, only phonological awareness predicted text reading fluency at this age. Longitudinal prediction of reading comprehension by both receptive vocabulary and morphological awareness was already evident at this age, as expected. Finally, spelling was predicted by preschool phonological awareness, as expected, as well as by morphological awareness, the contribution of which is expected to increase due to the spelling demands of Greek inflectional and derivational suffixes introduced at later grades.