Declarative memory supports children's math skills: A longitudinal study.

Substantial progress has been made in understanding the neurocognitive underpinnings of learning math. Building on this work, it has been hypothesized that declarative and procedural memory, two domain-general learning and memory systems, play important roles in acquiring math skills. In a longitudinal study, we tested whether in fact declarative and procedural memory predict children's math skills during elementary school years. A sample of 109 children was tested across grades 2, 3 and 4. Linear mixed-effects regression and structural equation modeling revealed the following. First, learning in declarative but not procedural memory was associated with math skills within each grade. Second, declarative but not procedural memory in each grade was related to math skills in all later grades (e.g., declarative memory in grade 2 was related to math skills in grade 4). Sensitivity analyses showed that the pattern of results was robust, except for the longitudinal prediction of later math skills when accounting for stable inter-individual differences via the inclusion of random intercepts. Our findings highlight the foundational role of early domain-general learning and memory in children's acquisition of math.

Spatiospectral image processing workflow considerations for advanced MR spectroscopy of the brain.

Magnetic resonance spectroscopy (MRS) is one of the few non-invasive imaging modalities capable of making neurochemical and metabolic measurements in vivo. Traditionally, the clinical utility of MRS has been narrow. The most common use has been the "single-voxel spectroscopy" variant to discern the presence of a lactate peak in the spectra in one location in the brain, typically to evaluate for ischemia in neonates. Thus, the reduction of rich spectral data to a binary variable has not classically necessitated much signal processing. However, scanners have become more powerful and MRS sequences more advanced, increasing data complexity and adding 2 to 3 spatial dimensions in addition to the spectral one. The result is a spatially- and spectrally-variant MRS image ripe for image processing innovation. Despite this potential, the logistics for robustly accessing and manipulating MRS data across different scanners, data formats, and software standards remain unclear. Thus, as research into MRS advances, there is a clear need to better characterize its image processing considerations to facilitate innovation from scientists and engineers. Building on established neuroimaging standards, we describe a framework for manipulating these images that generalizes to the voxel, spectral, and metabolite level across space and multiple imaging sites while integrating with LCModel, a widely used quantitative MRS peak-fitting platform. In doing so, we provide examples to demonstrate the advantages of such a workflow in relation to recent publications and with new data. Overall, we hope our characterizations will lower the barrier of entry to MRS processing for neuroimaging researchers.

Rapid Interactions of Widespread Brain Networks Characterize Semantic Cognition.

Language comprehension requires the rapid retrieval and integration of contextually appropriate concepts ("semantic cognition"). Current neurobiological models of semantic cognition are limited by the spatial and temporal restrictions of single-modality neuroimaging and lesion approaches. This is a major impediment given the rapid sequence of processing steps that have to be coordinated to accurately comprehend language. Through the use of fused functional magnetic resonance imaging and electroencephalography analysis in humans (n = 26 adults; 15 females), we elucidate a temporally and spatially specific neurobiological model for real-time semantic cognition. We find that semantic cognition in the context of language comprehension is supported by trade-offs between widespread neural networks over the course of milliseconds. Incorporation of spatial and temporal characteristics, as well as behavioral measures, provide convergent evidence for the following progression: a hippocampal/anterior temporal phonological semantic retrieval network (peaking at ∼300 ms after the sentence final word); a frontotemporal thematic semantic network (∼400 ms); a hippocampal memory update network (∼500 ms); an inferior frontal semantic syntactic reappraisal network (∼600 ms); and nodes of the default mode network associated with conceptual coherence (∼750 ms). Additionally, in typical adults, mediatory relationships among these networks are significantly predictive of language comprehension ability. These findings provide a conceptual and methodological framework for the examination of speech and language disorders, with additional implications for the characterization of cognitive processes and clinical populations in other cognitive domains.SIGNIFICANCE STATEMENT The present study identifies a real-time neurobiological model of the meaning processes required during language comprehension (i.e., "semantic cognition"). Using a novel application of fused magnetic resonance imaging and electroencephalography in humans, we found that semantic cognition during language comprehension is supported by a rapid progression of widespread neural networks related to meaning, meaning integration, memory, reappraisal, and conceptual cohesion. Relationships among these systems were predictive of individuals' language comprehension efficiency. Our findings are the first to use fused neuroimaging analysis to elucidate language processes. In so doing, this study provides a new conceptual and methodological framework in which to characterize language processes and guide the treatment of speech and language deficits/disorders.

Relational uncertainty: Does parental perception of adopted children's academic success change over time?

While initial findings suggested that children who are adopted (adoptees) perform less well academically, this result is not consistent across the literature. To explain these, often conflicting, results, researchers acquired a lagging view, in which adoptees need to "catch up" to their non-adopted peers. According to the lagging view, those adopted at a younger age have less catching up to do than those adopted when they are older. However, the lagging view does not account for the period in which adoptees and their new families adjust to one another. A period that we refer to as relational uncertainty. This is particularly relevant as data on adoptees' academic performance is largely based on parent reports. The overarching goal of this study was to determine if parental perception of adoptees' academic achievement changed over time, after accounting for the impact of age of adoption. Using a nationally representative dataset, we found that after accounting for age of adoption the length of time that children resided in their adoptive homes predicted parental perception of academic performance. Specifically, after accounting for age of adoption, parental perception of adoptees' academic performance demonstrated early consistency followed by a significant decline. We also investigated if the relation, of those factors previously associated with parental perception of adoptees' academic performance, remained after variance was accounted for by both age of adoption and children's length of stay in their adoptive homes. Several previous factors (where the child lived pre-adoption and the socioeconomic status of their adoptive household) and child characteristics (sex and the first language the child learned to speak) demonstrated a continued association. Results indicate the need for a paradigm shift in how we view parent reports of adoptees' academic achievement, as well as the frequently reported factors surrounding adoptees' academic performance. The implications for how to support adoptees' academic achievement are discussed.

The Contribution of Text Characteristics to Reading Comprehension: Investigating the Influence of Text Emotionality.

In the current study, we examined relations between text features (e.g., word concreteness, referential cohesion) and reading comprehension using multilevel logistic models. The sample was 158 native English-speaking students between 8 years 8 months and 11 years 2 months of age with a wide range of reading ability. In line with the simple view of reading, decoding ability and language comprehension were associated with reading comprehension performance. Text characteristics, including indices of word frequency, number of pronouns, word concreteness, and deep cohesion, also predicted unique variance in reading comprehension performance over and above the simple view's components. Additionally, the emotional charge of text (i.e., lexical ratings of arousal) predicted reading comprehension beyond traditional person-level and text-based characteristics. These findings add to a small but growing body of evidence suggesting that it is important to consider emotional charge in addition to person-level and text-based characteristics to better understand reading comprehension performance.

Parent-Child Shared Book Reading Mediates the Impact of Socioeconomic Status on Heritage Language Learners' Emergent Literacy.

The promotion of parent-child shared book reading for the development of children's literacy is a vital component of early literacy evidence-based recommendations. A robust body of research demonstrates that, regardless of socioeconomic status, parent-child shared book reading promotes monolingual children's literacy. However, despite the growing population of heritage language learners in the United States, those who grow up in homes where a familial language is spoken but receive English instruction at school, parent-child shared book reading research among heritage language learners remains scarce. Further, the impact of parent-child shared book reading is likely to alter the influence of family's socioeconomic status on heritage language learners' emergent literacy development. Here, parent-child shared book reading and children's emergent literacy were examined using latent variable path analyses in a national sample of 965 heritage language learners ages 2 to 6 years old. Parent-child shared book reading mediated the effect of socioeconomic status on heritage language learners' emergent literacy.

The influence of orthographic depth on multilinguals' neural networks.

Orthographic depth, the consistency and complexity of grapheme-phoneme correspondence, influences brain activation in multilinguals' first (L1) and second language (L2). The intrinsic functional connectivity of cross-language transfer was investigated between two groups of multilinguals, those whose L2 orthography is deeper than their L1 (S-to-D group) and those whose L2 orthography is shallower than their L1 (D-to-S group). Based on previous reports, we focused on two seed regions: the Visual Word Form Area (VWFA) and the left posterior supramarginal gyrus (pSMG). Group comparisons revealed stronger connectivity for the D-to-S group between the left pSMG and the right precuneus/cuneal cortex and the right SMG/angular gyrus. Moreover, we found that the greater the linguistic orthographic distance-the less similar in orthographic depth two languages are-the greater the negative connectivity between the left pSMG and the right pSMG, middle frontal gyrus (MFG) and frontal pole, and a cluster that included the inferior frontal gyrus (IFG) pars opercularis, frontal operculum, and insular cortex. When linguistic distance was greater, there was also greater negative connectivity between the VWFA and the left precuneus. Furthermore, stronger connectivity was found between the left pSMG and the right precuneus in multilinguals who spoke at least three languages (trilinguals) compared to those who only spoke two languages (bilinguals). Follow-up analyses revealed that this difference was driven by stronger intrinsic connectivity in D-to-S trilinguals compared to the S-to-D trilinguals. Taken together, the findings of this study suggest that multilinguals' intrinsic functional connectivity is shaped by the orthographic depth of their L2 in relation to L1, as well as differences between bilingualism and trilingualism.

Literacy-supporting skills in college students with specific reading comprehension deficit and developmental language disorder.

Specific reading comprehension deficit (S-RCD) and developmental language disorder (DLD) are both commonly occurring developmental disorders of language. The ways in which these disorders do and do not overlap during childhood are a matter of debate (Nation & Norbury, 2005). Moreover, in both populations, the challenges faced by individuals in adulthood are understudied. Here, we combined data across cohorts of college students, and classified individuals with only S-RCD (n = 20), only DLD (n = 55), and co-occurring S-RCD and DLD (n = 13). Individuals with good language and reading skills, who matched those with S-RCD on decoding, comprised our typical language and reading group (TD; n = 20). Beyond the measures used for classification, group-level differences were identified in sentence-level reading fluency, phonological processing, verbal working memory, and rapid automatized naming. We found that skill profiles differed across groups; however, we found no evidence of weaknesses beyond the core deficit in reading comprehension observed in those with only S-RCD. In contrast, when S-RCD co-occurs with DLD, weaknesses are observed in phonological processing, as well as reading fluency and verbal working memory. These findings suggest that some adults with S-RCD have co-occurring DLD as a core weakness. These findings, as well as differences between individuals with S-RCD and DLD, are further discussed.

Skill Profiles of College Students With a History of Developmental Language Disorder and Developmental Dyslexia.

Developmental language disorder (DLD) and developmental dyslexia (DD) are two prevalent subtypes of Specific Learning Disabilities (SLDs; Diagnostic and Statistical Manual of Mental Disorders [5th ed.; DSM-5]). Yet, little information is available regarding the distinct challenges faced by adults with DLD and/or DD in college. The purpose of the present report is to characterize the relative strengths and challenges of college students with a history of DLD and/or DD, as this information is critical for providing appropriate institutional support. We examined the cognitive skill profiles of 352 college students (ages 18-35 years), using standardized and research-validated measures of reading, spoken language, nonverbal cognition, and self-reported childhood diagnostic history. We classified college students as having DLD (n = 50), and/or DD (n = 40), or as typically developed adults (n = 132) according to procedures described for adults with DLD and DD. A structural equation model determined the cognitive, language, and reading measures predicted by the classification group. Adults with DLD demonstrated poor verbal working memory and speeded sentence-level reading. Adults with DD primarily demonstrated deficits in phonology-based skills. These results indicate that adults with DLD and/or DD continue to face similar challenges as they did during childhood, and thus may benefit from differentially targeted accommodations in college.

Left posterior prefrontal regions support domain-general executive processes needed for both reading and math.

Substantial evidence has suggested that reading and math are supported by executive processes (EP). However, to date little is known about which portion of the neural system underpinning domain-general executive skills works to support reading and math. In this study, we aimed to answer this question using fMRI via two complementary approaches. First, imaging data were acquired whilst a sample of 231 adolescents performed each of three separate tasks designed to assess reading comprehension, numerical magnitude estimation, and EP in working memory (WM), respectively. With careful task designs and conjunction analyses, we were able to isolate cross-domain brain activity specifically related to EP, as opposed to lower-level domain-general processes (e.g., visual processing). Second, the meta-analytic tool Neurosynth was used to independently identify brain regions involved reading, math, and EP. Using a combination of forward and reverse statistical inference and conjunction analyses, we again isolated brain regions specifically supporting domain-general EP. Results from both approaches yielded overlapping activation for reading, math, and EP in the left ventrolateral prefrontal cortex, left inferior frontal junction, and left precentral gyrus. This pattern suggests that posterior regions of the prefrontal cortex, rather than more central regions such as mid-DLPFC, play a leading role in supporting domain-general EP utilized by both reading and math.

Readers Recruit Executive Functions to Self-Correct Miscues During Oral Reading Fluency.

Reading fluency undoubtedly underlies reading competence; yet, the role of executive functions (EF) is less well understood. Here, we investigated the relationship between children's reading fluency and EF. Children's (n = 82) reading and language performance was determined by standardized assessments and EF by parental questionnaire. Results revealed that production of more miscues was explained by poorer reading and language performance and EF. Yet, self-correcting a miscue was predicted by better EF, beyond reading and language abilities. Intriguingly, EF partially mediated the relationship between reading and self-correction, suggesting that self-correction reflects parallel recruitment and coordination of domain-specific and domain-general processes.

The impact of expressive language development and the left inferior longitudinal fasciculus on listening and reading comprehension.

BACKGROUND: During the first 3-years of life, as the brain undergoes dramatic growth, children begin to develop speech and language. Hallmarks of this progression are seen when children reach developmental milestones, forming the foundation of language. Expressive language milestones, such as the production of a child's first word, are delayed in 5-8% of children. While for some children delays in reaching these milestones are harbingers of developmental disorders, for others expressive language delays appear to resolve. Regardless of whether or not early language skills appear resolved, difficulty with later comprehension is a likely outcome. Whether this heightened risk for poor comprehension differs based on text features, individual characteristics, or receipt of intervention remains unknown. Moreover, this relationship between expressive language development and comprehension is not yet linked to neurobiology, though the inferior longitudinal fasciculus (ILF) is a potential neurobiological correlate. Therefore, we investigated the impact of, and interactions between, expressive language development, early intervention, and the ILF on comprehension. METHODS: Longitudinal recurrent survival analyses predicted the risk of answering a comprehension question incorrectly. Predictors of comprehension included expressive language development, passage features, participant characteristics, fractional anisotropy, receipt of early intervention, and later diagnosis of speech or language disorders. RESULTS: Children with later expressive language milestones had poorer comprehension. When comprehension text features were examined, children with later milestones had poorer listening and reading comprehension, and poorer narrative and expository comprehension. The left ILF acted as a neurodevelopmental correlate, one that moderated the relationship between expressive language milestones and comprehension. Specifically, the left ILF exacerbated the relationship for those who did not receive early intervention and buffered the relationship for those who received intervention services. Early intervention decreased the risk of poor comprehension by 39% for children later diagnosed with a speech or language disorder. CONCLUSIONS: Early intervention should be provided for children with delayed expressive language milestones, particularly those who are at risk for speech or language disorders. The ILF plays a critical role in the relationship between expressive language development and comprehension, which may be that of a protective factor for children with the most severe early issues with speech and language.

Learning Lexical Information Depends Upon Task, Learning Approach, and Reader Subtype.

Learning to read relies upon the integration of phonological, orthographic, and semantic information. However, no studies have investigated how children with varying reading abilities learn phonological-orthographic (PO) and semantic aspects of novel words as a function of both learning approach (LA; e.g., learning new words in isolation or context) and outcome (fluency or comprehension). In this study, 45 children participated in three tasks that differentially tested PO and semantic attributes of novel pseudo-words learned through two learning approaches. Children were classified into groups as having dyslexia (DYS), having specific reading comprehension deficits (S-RCDs), or being typically developing readers (TD). Differences were found between groups, with S-RCD poorer than TD on semantic but not PO components of learning. Children with DYS displayed impaired results on both semantic and PO learning but showed an interaction on task by LA performance. Specifically, in the DYS group, isolation LA yielded better performance on PO learning, while context LA was better for semantic learning. These results indicate that (a) children with S-RCDs have a unique learning profile that is dissociable from DYS and TD and (b) reading impairments are not static but rather influence acquisition of reading skill in different ways, depending on reading profile.

Characterizing and decomposing the neural correlates of individual differences in reading ability among adolescents with task-based fMRI.

To better characterize the neural correlates of the full spectrum of reading ability, this fMRI study examined how variations in reading ability correlate with task-based brain activity during reading among a large community sample of adolescents (N = 234). In addition, complimentary approaches taking advantage of empirical as well as independent meta-analytic information were employed to isolate neural substrates of domain-general executive processes that are predictive of reading ability. Age-related differences in brain activity were also examined. Better reading was associated with increased activation in left anterior and inferior temporal regions and parts of orbitofrontal cortex, along with reduced activation in the thalamus and left frontal eye field (FEF). Converging evidence suggests that FEF activity corresponds to executive processes during reading. In contrast, activity in temporal regions is likely to reflect cognitive processes specific to reading. Older adolescents also demonstrated increased activation in an orbitofrontal region that overlaps with the aforementioned age-independent, reading-related regions, along with reduced activity in parietal and occipital regions. These results suggest that comparedto poor readers, proficient readers benefit from efficient reading-specific processes and require less executive effort, implemented via the FEF, during a reading comprehension task.

Fairy Tales versus Facts: Genre Matters to the Developing Brain.

Neurobiological studies of discourse comprehension have almost exclusively focused on narrative comprehension. However, successful engagement in modern society, particularly in educational settings, also requires comprehension with an aim to learn new information (i.e., "expository comprehension"). Despite its prevalence, no studies to date have neurobiologically characterized expository comprehension as compared with narrative. In the current study, we used functional magnetic resonance imaging in typically developing children to test whether different genres require specialized brain networks. In addition to expected activations in language and comprehension areas in the default mode network (DMN), expository comprehension required significantly greater activation in the frontoparietal control network (FPN) than narrative comprehension, and relied significantly less on posterior regions in the DMN. Functional connectivity analysis revealed that, compared with narrative, the FPN robustly correlated with the DMN, and this inter-network communication was higher with increased reading expertise. These findings suggest that, relative to narrative comprehension, expository comprehension shows (1) a unique configuration of the DMN, potentially to support non-social comprehension processes, and (2) increased utilization of top-down regions to help support goal-directed comprehension processes in the DMN. More generally, our findings reveal that different types of discourse-level comprehension place diverse neural demands on the developing brain.

Neurochemistry Predicts Convergence of Written and Spoken Language: A Proton Magnetic Resonance Spectroscopy Study of Cross-Modal Language Integration.

Recent studies have provided evidence of associations between neurochemistry and reading (dis)ability (Pugh et al., 2014). Based on a long history of studies indicating that fluent reading entails the automatic convergence of the written and spoken forms of language and our recently proposed Neural Noise Hypothesis (Hancock et al., 2017), we hypothesized that individual differences in cross-modal integration would mediate, at least partially, the relationship between neurochemical concentrations and reading. Cross-modal integration was measured in 231 children using a two-alternative forced choice cross-modal matching task with three language conditions (letters, words, and pseudowords) and two levels of difficulty within each language condition. Neurometabolite concentrations of Choline (Cho), Glutamate (Glu), gamma-Aminobutyric (GABA), and N- acetyl-aspartate (NAA) were then measured in a subset of this sample (n = 70) with Magnetic Resonance Spectroscopy (MRS). A structural equation mediation model revealed that the effect of cross-modal word matching mediated the relationship between increased Glu (which has been proposed to be an index of neural noise) and poorer reading ability. In addition, the effect of cross-modal word matching fully mediated a relationship between increased Cho and poorer reading ability. Multilevel mixed effects models confirmed that lower Cho predicted faster cross-modal matching reaction time, specifically in the hard word condition. These Cho findings are consistent with previous work in both adults and children showing a negative association between Cho and reading ability. We also found two novel neurochemical relationships. Specifically, lower GABA and higher NAA predicted faster cross-modal matching reaction times. We interpret these results within a biochemical framework in which the ability of neurochemistry to predict reading ability may at least partially be explained by cross-modal integration.

Dysfunction of Rapid Neural Adaptation in Dyslexia.

Identification of specific neurophysiological dysfunctions resulting in selective reading difficulty (dyslexia) has remained elusive. In addition to impaired reading development, individuals with dyslexia frequently exhibit behavioral deficits in perceptual adaptation. Here, we assessed neurophysiological adaptation to stimulus repetition in adults and children with dyslexia for a wide variety of stimuli, spoken words, written words, visual objects, and faces. For every stimulus type, individuals with dyslexia exhibited significantly diminished neural adaptation compared to controls in stimulus-specific cortical areas. Better reading skills in adults and children with dyslexia were associated with greater repetition-induced neural adaptation. These results highlight a dysfunction of rapid neural adaptation as a core neurophysiological difference in dyslexia that may underlie impaired reading development. Reduced neurophysiological adaptation may relate to prior reports of reduced behavioral adaptation in dyslexia and may reveal a difference in brain functions that ultimately results in a specific reading impairment.

Brain bases of reading fluency in typical reading and impaired fluency in dyslexia.

Although the neural systems supporting single word reading are well studied, there are limited direct comparisons between typical and dyslexic readers of the neural correlates of reading fluency. Reading fluency deficits are a persistent behavioral marker of dyslexia into adulthood. The current study identified the neural correlates of fluent reading in typical and dyslexic adult readers, using sentences presented in a word-by-word format in which single words were presented sequentially at fixed rates. Sentences were presented at slow, medium, and fast rates, and participants were asked to decide whether each sentence did or did not make sense semantically. As presentation rates increased, participants became less accurate and slower at making judgments, with comprehension accuracy decreasing disproportionately for dyslexic readers. In-scanner performance on the sentence task correlated significantly with standardized clinical measures of both reading fluency and phonological awareness. Both typical readers and readers with dyslexia exhibited widespread, bilateral increases in activation that corresponded to increases in presentation rate. Typical readers exhibited significantly larger gains in activation as a function of faster presentation rates than readers with dyslexia in several areas, including left prefrontal and left superior temporal regions associated with semantic retrieval and semantic and phonological representations. Group differences were more extensive when behavioral differences between conditions were equated across groups. These findings suggest a brain basis for impaired reading fluency in dyslexia, specifically a failure of brain regions involved in semantic retrieval and semantic and phonological representations to become fully engaged for comprehension at rapid reading rates.

Phonemic restoration in developmental dyslexia.

The comprehension of fluent speech in one's native language requires that listeners integrate the detailed acoustic-phonetic information available in the sound signal with linguistic knowledge. This interplay is especially apparent in the phoneme restoration effect, a phenomenon in which a missing phoneme is "restored" via the influence of top-down information from the lexicon and through bottom-up acoustic processing. Developmental dyslexia is a disorder characterized by an inability to read at the level of one's peers without any clear failure due to environmental influences. In the current study we utilized the phonemic restoration illusion paradigm to examine individual differences in phonemic restoration across a range of reading ability, from very good to dyslexic readers. Results demonstrate that restoration occurs less in those who have high scores on measures of phonological processing. Based on these results, we suggest that the processing or representation of acoustic detail may not be as reliable in poor and dyslexic readers, with the result that lexical information is more likely to override acoustic properties of the stimuli. This pattern of increased restoration could result from a failure of perceptual tuning, in which unstable representations of speech sounds result in the acceptance of non-speech sounds as speech. An additional or alternative theory is that degraded or impaired phonological processing at the speech sound level may reflect architecture that is overly plastic and consequently fails to stabilize appropriately for speech sound representations. Therefore, the inability to separate speech and noise may result as a deficit in separating noise from the acoustic signal.

Glutamate and choline levels predict individual differences in reading ability in emergent readers.

Reading disability is a brain-based difficulty in acquiring fluent reading skills that affects significant numbers of children. Although neuroanatomical and neurofunctional networks involved in typical and atypical reading are increasingly well characterized, the underlying neurochemical bases of individual differences in reading development are virtually unknown. The current study is the first to examine neurochemistry in children during the critical period in which the neurocircuits that support skilled reading are still developing. In a longitudinal pediatric sample of emergent readers whose reading indicators range on a continuum from impaired to superior, we examined the relationship between individual differences in reading and reading-related skills and concentrations of neurometabolites measured using magnetic resonance spectroscopy. Both continuous and group analyses revealed that choline and glutamate concentrations were negatively correlated with reading and related linguistic measures in phonology and vocabulary (such that higher concentrations were associated with poorer performance). Correlations with behavioral scores obtained 24 months later reveal stability for the relationship between glutamate and reading performance. Implications for neurodevelopmental models of reading and reading disability are discussed, including possible links of choline and glutamate to white matter anomalies and hyperexcitability. These findings point to new directions for research on gene-brain-behavior pathways in human studies of reading disability.