Modelling individual differences in reading using an optimised MikeNet simulator: the impact of reading instruction.

Reading is vital for acquiring knowledge and studies have demonstrated that phonology-focused interventions generally yield greater improvements than meaning-focused interventions in English among children with reading disabilities. However, the effectiveness of reading instruction can vary among individuals. Among the various factors that impact reading skills like reading exposure and oral language skills, reading instruction is critical in facilitating children's development into skilled readers; it can significantly influence reading strategies, and contribute to individual differences in reading. To investigate this assumption, we developed a computational model of reading with an optimised MikeNet simulator. In keeping with educational practices, the model underwent training with three different instructional methods: phonology-focused training, meaning-focused training, and phonology-meaning balanced training. We used semantic reliance (SR), a measure of the relative reliance on print-to-sound and print-to-meaning mappings under the different training conditions in the model, as an indicator of individual differences in reading. The simulation results demonstrated a direct link between SR levels and the type of reading instruction. Additionally, the SR scores were able to predict model performance in reading-aloud tasks: higher SR scores were correlated with increased phonological errors and reduced phonological activation. These findings are consistent with data from both behavioral and neuroimaging studies and offer insights into the impact of instructional methods on reading behaviors, while revealing individual differences in reading and the importance of integrating OP and OS instruction approaches for beginning readers.

Do the relations of vocabulary and attentional control with word reading and spelling change as a function of development and spelling scoring method?

The current study examined the potentially changing relations of vocabulary knowledge and attentional control with word reading and spelling from Grade 2 to Grade 4. Spelling was scored using a conventional correctness score and an alternative nonbinary scoring method that reflects the degree of correctness (i.e., text distance). A total of 165 Grade 2 English-speaking children in the United States were longitudinally followed from Grade 2 to Grade 4 with annual assessments on word reading, spelling, vocabulary, and attentional control. Results from multiple linear regression models in each grade revealed that spelling was significantly related with vocabulary in Grades 3 and 4 and to attentional control in Grades 2 and 3. A reverse pattern emerged for word reading, where word reading was significantly related with vocabulary only in Grade 2 and to attentional control only in Grade 4. The results were similar for either spelling scoring method. Our findings underscore the dynamic relations of vocabulary and attentional control with word reading and spelling for children in Grades 2 to 4. Nonbinary scoring methods for spelling such as text distance might not provide additional insights compared with conventional correctness scores for the relations of vocabulary and attentional control with spelling.

Morphological Assessment Features and their Relations to Reading: A Meta-Analytic Structural Equation Modeling Study.

Morphemes are the smallest meaningful unit of language (e.g., affixes, base words) that express grammatical and semantic information. Additionally, morphological knowledge is significantly related to children's word reading and reading comprehension skills. Researchers have broadly assessed morphological knowledge by using a wide range of tasks and stimuli, which has influenced the interpretation of the relations between morphological knowledge and reading outcomes. This review of 103 studies used meta-analytic structural equation modeling (MASEM) to investigate the relations between commonly occurring morphological knowledge assessment features (e.g., written versus oral, spelling versus no spelling) in the literature to reading outcomes, including word reading and reading comprehension. Meta-regression techniques were used to examine moderators of age and reading ability. Morphological assessments that used a written modality (e.g., reading, writing) were more predictive of word reading outcomes than those administered orally. Assessments of morphological spelling were more predictive of both word reading and reading comprehension outcomes than those that did not examine spelling accuracy. Age was a significant moderator of the relation between morphology and word reading, such that the relation was stronger for the younger than the older children. Younger children also demonstrated higher relations between multiple task dimensions and reading comprehension, including oral tasks, tasks without decoding, and tasks that provided context clues. These findings have important implications for future morphological intervention studies aimed to improve children's reading outcomes, in particular the use of orthography and spelling within the context of teaching morphology.

Early skills that predict English reading ability: A longitudinal study of bilingual children from 5 to 10 years.

Despite substantial research, the contribution of oral language skills acquired in Spanish to Spanish-English bilingual children's acquisition of English reading skill is unclear. The current study addressed this question with data on the oral language and pre-literacy skills of 101 Spanish-English bilingual learners at 5 years of age and their English word reading (i.e., decoding) and reading comprehension skills at 6, 7, 8, 9, and 10 years. Separate multilevel models using English language, Spanish language, and pre-literacy skills as predictors of these outcomes identified English phonological awareness, Spanish phonological awareness, and concepts of print knowledge as positive predictors of word reading. A final model including all these significant predictors found only Spanish phonological awareness and concept of print to be significant predictors. Significant predictors of reading comprehension in separate models were English vocabulary, Spanish phonological awareness, and concepts about print. In the final model, only English vocabulary and Spanish phonological awareness predicted English reading comprehension. These findings provide evidence that phonological awareness is a language-general skill that supports reading across languages, consistent with the common underlying proficiency model of bilingual reading development. The finding that only English vocabulary predicts English reading comprehension suggests that vocabulary knowledge is not part of a common underlying proficiency but is language specific in its value to reading ability.

Language and reading in attention-deficit/hyperactivity disorder and comorbid attention-deficit/hyperactivity disorder + developmental language disorder.

Background: The current study sought to examine whether psycholinguistic assessments could discriminate children and adolescents with developmental language disorder (DLD) from those with attention-deficit/hyperactivity disorder (ADHD; combined or inattentive subtype) and comorbid DLD + ADHD. Methods: The Clinical Evaluation of Language Fundamentals-Screening Test (CELFST; Wiig et al., 2013), the Comprehensive Test of Phonological Processing (nonword repetition subtest; Wagner et al., 2013), and the Test of Word Reading Efficiency (sight word and phonemic decoding subtests; Torgesen et al., 2012) were examined in 441 children and adolescents between 6 and 16 years of age. Results: The presence of a language disorder (with or without ADHD) predicted poor performance across tasks. Children and adolescents with ADHD (combined vs. inattentive) only significantly differed in sight word reading, in favor of those with combined type. Measures of reading efficiency could distinguish between the two types of ADHD, but not between other groups. Interestingly, scores on the standard language screener were no worse for children with ADHD + DLD than children with DLD only. Conclusions: The combination of comorbid ADHD + DLD did not appear to be associated with lower language abilities, sight word reading, or phonemic decoding relative to DLD alone. Reading efficiency was effective in discriminating between ADHD subtypes. These findings offer valuable insights into differential diagnosis and the identification of comorbidity.

Aprendizaje de la lectura mediante la asociación imagen- palabra escrita: una revisión de la evidencia en niños con discapacidad intelectual y autismo

Se tiene como objetivo determinar si la asociación imagen - palabra escrita, como parte del método de instrucción de palabras a la vista limita la adquisición del aprendizaje de la lectura en niños con discapacidad intelectual y autismo. Para lo cual, se realizó una revisión narrativa de los estudios reportados en las bases de datos de Scopus, Willey, ScienceDirect, Taylor & Francis, y Sage. Los hallazgos evidencian que la presentación de imagen y palabra escrita como estímulo compuesto puede obstaculizar el proceso de reconocimiento del texto, lo que sugiere la necesidad de emplear esta estrategia con precaución. En consecuencia, se recomienda fomentar actividades de aprendizaje donde la palabra escrita se presente de manera independiente; entre las prácticas alternativas que pueden implementarse, destacan la presentación de la imagen como retroalimentación posterior a la exposición aislada de la palabra escrita. Otra opción viable consiste en mostrar la palabra escrita, seguida de la instrucción de hacer coincidir palabra con imagen.

The objective was to determine if the image-written word association, as part of the straight forward word instruction method, limits the acquisition of learning to read in children with intellectual disabilities and autism. For which, a narrative review of the studies reported in the Scopus, Willey, ScienceDirect, Taylor & Francis, and Sage databases was carried out. It was considered, the presentation of an image and a written word as a compound stimulus can hinder the text recognition process, suggesting the need to use this strategy with caution. Consequently, it is recommended to encourage learning activities where the written word is presented independently. However, it is possible to use the images as feedback, in order to avoid the negative effect of the images.

O objetivo foi verificar se a associação imagem-palavra escrita, como parte do método de instrução das palavras simples, limita a aquisição da aprendizagem da leitura em crianças com deficiência intelectual e autismo. Para isso, foi realizada uma revisão narrativa dos estudos relatados nas bases de dados Scopus, Willey, ScienceDirect, Taylor & Francis e Sage. Considerou-se que a apresentação de uma imagem e uma palavra escrita, e apresentá-la como um estímulo composto, pode dificultar o reconhecimento do texto, sugerindo a necessidade de emprego dessa estratégia com cautela. Nesse sentido, recomenda-se promover atividades de aprendizagem onde a palavra escrita deve ser apresentado sozinho. No entanto, é possível usar as imagens como feedback, a fim de evitar o efeito negativo das imagens.

The relationship between vocabulary depth knowledge, word reading, and reading comprehension in Chinese.

Although vocabulary depth (VD) is recognized as a crucial factor in reading comprehension, the investigation of its role in reading comprehension remains insufficient. This study aimed to address two significant research gaps in this domain. First, empirical evidence is needed to explore the construct of VD knowledge, particularly within the Chinese language. Second, the underlying mechanism that connects VD and reading comprehension requires further clarification. In this study, a sample of 326 native Chinese students from Grade 4 participated in a comprehensive battery of tests assessing VD knowledge, word reading, and reading comprehension. Based on theoretical frameworks of VD knowledge, we measured six subtypes of VD knowledge: polysemy, collocation, word register, part-of-speech, semanticassociations, and homonyms. The results of factor analysis revealed that Chinese VD knowledge can be conceptualized as a two-factor construct, encompassing in-depth semantic knowledge (VD-meaning) and knowledge of word usage (VD-usage). Both VD-meaning and VD-usage demonstrated significant direct effects on reading comprehension, highlighting the critical role of VD in determining reading comprehension outcomes in Chinese. Furthermore, our findings indicated an indirect contribution of VD to reading comprehension, specifically through the mediating effect of word reading on the relationship between VD-meaning and reading comprehension. This study represents a pioneering empirical investigation that delved into the construct of VD in Chinese. In addition, we discuss the role of VD knowledge and its interaction with word reading in the context of Chinese reading comprehension, which could significantly enhance our understanding of the underlying mechanism that links vocabulary knowledge to reading comprehension.

Preschool emergent literacy skills as predictors of reading and spelling in Grade 2 and the role of migration background in Germany.

Children's emergent literacy skills are essential for the development of later literacy abilities and school success. However, children with migration background often show poorer language skills in the majority language and are at a greater risk of developing literacy deficits. In addition, there is evidence for the predictive role of emergent literacy skills in reading comprehension, but there has been relatively little research concerning the association between preschool emergent literacy skills and word reading and spelling in Germany, especially for children with migration background. This study examines the associations of emergent literacy skills (vocabulary, phonological awareness [PA], letter knowledge, and rapid naming) with word reading and spelling from kindergarten to the end of Grade 2 and evaluates the role of migration background (i.e., use of the majority or minority language at home) in these associations. Data from 187 preschool children were obtained before school entry (Mage = 63.58 months, SD = 4.45). The results show that vocabulary and letter knowledge were strong predictors of word reading, whereas letter knowledge and PA were significant predictors of spelling. Furthermore, children's migration background was negatively associated with preschool vocabulary and PA. For children with migration background, vocabulary was a significant predictor of word reading, whereas letter knowledge was the best predictor of word reading for children without migration background. The results reflect the complexity of language development and the relevance of emergent literacy skills as predictors for word reading and spelling. Specific interventions should be developed to promote children's literacy abilities.

Comorbid Word Reading and Mathematics Computation Difficulty at Start of First Grade.

The purpose of this analysis was to describe cognitive processes associated with comorbid difficulty between word reading (WR) and mathematics computation (MC) at the start of first grade among children selected for WR and MC delays. A sample of 234 children (mean age 6.50 years, SD = 0.31) was assessed on WR, MC, core cognitive processes (phonological processing, rapid automatized naming, verbal counting [VC]), and domain-general cognitive processes (working memory, oral language, nonverbal reasoning, attentive behavior). Structural equation modeling was used to predict a latent Comorbidity factor, which modeled shared variance between WR and MC, and to identify processes associated with that Comorbidity factor. Results identified each of the core cognitive processes, especially VC, and each of the domain-general cognitive processes, especially working memory, as explaining shared variance between WR and MC. Implications for understanding comorbid difficulty at the start of first grade and designing coordinated first-grade interventions are discussed.

The influence of segmental and suprasegmental phonological awareness on word and pseudoword reading-A comparison between native English speakers and native Chinese speakers of English.

Segmental and suprasegmental phonological awareness (PA) are closely related to word reading skills in native speakers learning to read an alphabetic script as used in English. However, their roles in English word and pseudoword reading among native Chinese (NC) speakers, and how English proficiency might affect these relationships, remain less clear. This study examined the links between English segmental/suprasegmental PA and word/pseudoword reading in NC and native English (NE) speakers. Both child and adult participants were assessed on English segmental and suprasegmental PA, alongside vocabulary, at a single time point. The results showed that both segmental PA (elision and segmenting nonwords) and suprasegmental PA (aural suffix judgment and written suffix judgment) were significantly correlated with English real word and pseudoword reading of both NE and NC children, and NC adults, but not NE adults. Moreover, for NE and NC children, segmental PA correlated stronger with real word reading than suprasegmental PA after controlling for vocabulary. Among NC adults, both segmental and suprasegmental PA significantly contributed to real word reading. For pseudoword reading, after controlling for vocabulary, segmental PA had a stronger correlation among NC children and adults, while suprasegmental PA was more influential for NE children. This research gives insights into factors influencing NC speakers' English word reading ability, bearing essential implications for enhancing second language literacy in learners from a logographic background.

Early language dissociation in bilingual minds: magnetoencephalography evidence through a machine learning approach.

Does neural activity reveal how balanced bilinguals choose languages? Despite using diverse neuroimaging techniques, prior studies haven't provided a definitive solution to this problem. Nonetheless, studies involving direct brain stimulation in bilinguals have identified distinct brain regions associated with language production in different languages. In this magnetoencephalography study with 45 proficient Spanish-Basque bilinguals, we investigated language selection during covert picture naming and word reading tasks. Participants were prompted to name line drawings or read words if the color of the stimulus changed to green, in 10% of trials. The task was performed either in Spanish or Basque. Despite similar sensor-level evoked activity for both languages in both tasks, decoding analyses revealed language-specific classification ~100 ms post-stimulus onset. During picture naming, right occipital-temporal sensors predominantly contributed to language decoding, while left occipital-temporal sensors were crucial for decoding during word reading. Cross-task decoding analysis unveiled robust generalization effects from picture naming to word reading. Our methodology involved a fine-grained examination of neural responses using magnetoencephalography, offering insights into the dynamics of language processing in bilinguals. This study refines our understanding of the neural underpinnings of language selection and bridges the gap between non-invasive and invasive experimental evidence in bilingual language production.

The Role of Verbal Fluency as a Variable in Reading and Comprehension Skills in Bengali.

The study explored the role of verbal fluency in determining reading and comprehension skills in Bengali among 10-year old typically developing Bengali children. Robust correlations were found between semantic fluency and word reading (0.63) as well as semantic fluency and comprehension (0.70). Good correlation was found between letter fluency and comprehension (0.49), and, word reading and comprehension (0.62). The findings suggest that good word storing capacity and executive functions led to enhanced automaticity of retrieval and verbal fluency, which together with improved orthographic and phonological processing led to good word reading scores, contributing to lesser cognitive load thereby easing out the complex text comprehension task. Transcending narrow empirical base of reading theories derived from Western writing typologies delimited to orthographic depth and psycholinguistic grain size, the study contends that verbal fluency is another interesting variable determining the reading and comprehension skills in Bengali along with visuo-spatial complexity and complex phonology-orthography inconsistencies.

The effect of attention shifting on Chinese children's word reading in primary school.

BACKGROUND: This study explored the effects of attention shifting on Chinese children's word reading. OBJECTIVE: The sample consisted of 87 fourth-grade children from Shaoxing City, China. METHODS: The students completed measures of the attention shifting task, reading accuracy test, reading fluency test, and rapid automatized naming test. RESULTS: The results showed that reading fluency was significantly correlated with attention shifting scores, specifically with tag1 and tag6 (ps < 0.05). The reading accuracy score was also significantly correlated with tag6 (p < 0.05). According to the regression analysis of attention shifting on word reading, even when controlling for rapid automatic naming, attention shifting significantly affected word reading fluency at approximately 600 ms (p = .011). Attention shifting did not affect children's word reading accuracy. SHORT CONCLUSION: These findings suggest that attention shifting is significantly associated with children's word reading. Educators should focus on developing children's attention shifting to improve their word reading ability.

Executive functions underlie word reading and reading fluency in Chinese children with attention deficit/hyperactivity disorder, reading disabilities, and comorbid attention deficit/hyperactivity disorder and reading disabilities.

The current study examined the executive function (EF) deficits and their roles in reading in one hundred and four Cantonese-speaking children with typical development, reading disabilities (RD), ADHD, and comorbid ADHD and RD (ADHD + RD). Children's EF and reading skills were measured. Analysis of variance results showed that all children with disorders manifested deficits in verbal and visuospatial short-term and working memory and behavioral inhibition. Moreover, children with ADHD and ADHD + RD also exhibited deficits in inhibition (IC and BI) and cognitive flexibility. These findings demonstrated that the EF deficits in Chinese children with RD, ADHD, and ADHD + RD are similar to those in their counterparts using alphabetic languages. However, children with ADHD + RD displayed more severe deficits in visuospatial working memory compared to children with RD and ADHD, which was inconsistent with that observed in children using alphabetic languages. Regression analysis results showed that verbal short-term memory was a significant predictor for both word reading and reading fluency in children with RD and ADHD + RD. Moreover, behavioral inhibition significantly predicted reading fluency in children with ADHD. These findings also agreed with previous studies. Collectively, the results of the current study showed that the EF deficits and their roles in reading found in Chinese children with RD, ADHD, and ADHD + RD are mainly consistent with children using alphabetic languages. However, more studies are still needed to confirm these findings, especially comparing the severity of working memory among these three disorders.

Phonological Awareness and Rapid Automatized Naming: The Mediating Effect of Word Reading and Spelling in Children with Developmental Dyslexia, Attention Deficit Hyperactivity Disorder, and Mild Intellectual Disability.

INTRODUCTION: In learning to read, children learn to integrate orthographic, phonological, and semantic codes into highly specified and redundant lexical representations. The aim is to test a proposed model for the relationship between phonological awareness (PA) and rapid automatized naming (RAN) as mediated by word reading (WR) and spelling (SP) in children with developmental dyslexia (DD), attention deficit hyperactivity disorder (ADHD), and mild intellectual disability (ID). METHODS: The relation between PA and RAN was found to be mediated by WR and SP in children with DD, ADHD, and mild ID. Three groups of children were included: DD children (N = 70), ADHD children (N = 68), and ID children (N = 69). This is a quantitative correlational, cross-sectional study investigating the strength and direction of relationships among proposed variables. RESULTS: The relation between PA and RAN was found to be mediated by WR and SP. Based on their correlation analysis, the researcher concluded that there are significant correlations between PA, RAN, WR, and SP. PA correlates positively with RAN and SP. RAN correlates positively with WR and SP. CONCLUSION: The study extended our knowledge of the relationship between PA and RAN as mediated by WR and SP in children with DD, ADHD, and mild ID. In practice, this is conducive to promote the utilization of "PA" and "RAN" so as to improve the early literacy skills (WR and SP) among children with DD, ADHD, and mild ID.

Brain bases of morphological awareness and longitudinal word reading outcomes.

Children's spoken language skills are essential to the development of the "reading brain," or the neurocognitive systems that underlie successful literacy. Morphological awareness, or sensitivity to the smallest units of meaning, is a language skill that facilitates fluent recognition of meaning in print. Yet despite the growing evidence that morphology is integral to literacy success, associations among morphological awareness, literacy acquisition, and brain development remain largely unexplored. To address this gap, we conducted a longitudinal investigation with 75 elementary school children (5-11 years of age) who completed an auditory morphological awareness neuroimaging task at Time 1 as well as literacy assessments at both Time 1 and Time 2 (1.5 years later). Findings reveal longitudinal brain-behavior associations between morphological processing at Time 1 and reading outcomes at Time 2. First, activation in superior temporal brain regions involved in word segmentation was associated with both future reading skill and steeper reading gains over time. Second, a wider array of brain regions across the language network were associated with polymorphemic word reading as compared with broader word reading skill (reading both simple and complex words). Together, these findings reinforce the importance of word segmentation skills in learning to read and highlight the importance of considering complex word reading skills in building comprehensive neurocognitive models of literacy. This study fills a gap in our knowledge of how processing meaningful units in speech may help to explain differences in children's reading development over time and informs ongoing theoretical questions about the role of morphology in learning to read.

The effect of attention shifting on Chinese children's word reading in primary school

Abstract Background This study explored the effects of attention shifting on Chinese children's word reading. Objective The sample consisted of 87 fourth-grade children from Shaoxing City, China. Methods The students completed measures of the attention shifting task, reading accuracy test, reading fluency test, and rapid automatized naming test. Results The results showed that reading fluency was significantly correlated with attention shifting scores, specifically with tag1 and tag6 (ps < 0.05). The reading accuracy score was also significantly correlated with tag6 (p < 0.05). According to the regression analysis of attention shifting on word reading, even when controlling for rapid automatic naming, attention shifting significantly affected word reading fluency at approximately 600 ms (p = .011). Attention shifting did not affect children's word reading accuracy. Short conclusion These findings suggest that attention shifting is significantly associated with children's word reading. Educators should focus on developing children's attention shifting to improve their word reading ability.

Longitudinal Predictors of Word Reading for Children with Williams Syndrome.

We examined the cognitive, language, and instructional predictors of early word-reading ability in a sample of children with Williams syndrome longitudinally. At Time 1, sixty-nine 6-7-year-olds (mean age = 6.53 years) completed standardized measures of phonological awareness, visual-spatial perception, vocabulary, and overall intellectual ability. Word-reading instruction type was classified as (systematic) Phonics (n = 35) or Other (n = 34). At Time 2, approximately three years later (mean age = 9.47 years), children completed a standardized assessment of single-word reading ability. Reading ability at Time 2 varied considerably, from inability to read any words to word-reading ability slightly above the level expected for age. The results of a multiple regression indicated that Time 1 word-reading instruction type, phonological awareness, and visual-spatial perception (as assessed by a matching letter-like forms measure) each explained significant unique variance in word reading at Time 2. A systematic phonics approach was associated with significantly better performance than other reading-instruction approaches. Exploratory analyses suggested that the relations between these factors were complex. Considered together, these findings strongly suggest that, in line with the Cumulative Risk and Resilience Model of reading disability, word-reading (dis)ability in Williams syndrome is probabilistic in nature, resulting from the interaction of multiple individual and environmental risk and protective factors. The results also have educational implications: Early word-reading instruction for children with Williams syndrome should combine systematic phonics and phonological awareness training while also incorporating letter discrimination instruction highlighting the visual-spatial differences between similar-appearing letters.

The Role of Morphological Decomposition in Reading Complex Words in Arabic in Elementary School Years.

We examined the role of morphological processing in the reading of inflections and derivations in Arabic, a morphologically-rich language, among 228 first-graders and 230 second-graders. All words were morphologically complex, with differences in number of morphemes and morphological transparency. Inflections consisted of three morphemes, with high transparency of the root morpheme, while derivations consisted of two morphemes with lower transparency of the root. Results indicated that, despite their matching in frequency and syllabic length, reading performances of derivations was better than those of inflections. That is, three-morphemic highly transparent inflections were read slower and involved more errors than bi-morphemic less transparent derivations. These differences in reading performance between inflectional and derivational words might suggest that Arab-speaking novice readers use a morphological decomposition process that is reflected in reading accuracy and fluency. The results highlight the important role morphology has in reading, even at a young age, along with reading acquisition.

Neural specialization to English words in Chinese children: Joint contribution of age and English reading abilities.

N1 tuning to words, a neural marker of visual word recognition, develops by an interaction between age and ability. The development of N1 tuning to a second learnt print is unclear. The present study examined the joint contribution of age and English reading abilities to N1 amplitude and tuning to English print in Chinese children in Hong Kong. EEG signals were recorded from 179 children (six to nine years old) while they were performing a repetition detection task comprised of different print stimuli measuring three types of tuning, i.e., coarse tuning (real word versus false font), fine tuning (real versus nonword), and lexicality effect (real versus pseudo word). Children were assessed in English word reading accuracy (EWR) and English sub-lexical orthographic knowledge (EOK). Results indicated that coarse tuning decreased with age but increased with EWR and EOK. Fine tuning uniquely increased with EOK, and the lexicality effect increased with EWR. At last, higher EWR was linked to less right-lateralized coarse tuning in younger children. Taken together, the findings support the visual perceptual expertise account in the L2 context, in that N1 coarse tuning, fine tuning, and lexicality effect are driven by skill improvement.