Modulating Phonological Working Memory With Anodal High-Definition Transcranial Direct Current Stimulation to the Anterior Portion of the Supplementary Motor Area.

BACKGROUND: Phonological working memory is key to vocabulary acquisition, spoken word recognition, real-time language processing, and reading. Transcranial direct current stimulation, when coupled with behavioral training, has been shown to facilitate speech motor output processes, a key component of nonword repetition, the primary task used to assess phonological working memory. In this study, we examined the efficacy of combining overt nonword repetition training with anodal high-definition transcranial direct current stimulation (HD tDCS) to the presupplementary motor area (preSMA) to enhance nonword repetition. OBJECTIVE: This study investigated whether 20 min of active or sham anodal HD tDCS targeting preSMA concurrently with a nonword repetition task differentially impacted nonword repetition ability. METHOD: Twenty-eight neurotypical college-age adults (18-25 years; 19 females, eight males, one nonbinary) completed a 20-min nonword repetition training task where they received either active or sham 1-mA anodal HD tDCS to the preSMA while overtly repeating a list of four-, five-, six-, and seven-syllable English-like nonwords presented in a random order. Whole nonword accuracy and error patterns (phoneme and syllable) were measured prior to and following training. RESULTS: Following training, both groups showed a decrease in nonword repetition accuracy. The drop in performance was significantly greater for the active stimulation group compared to the sham stimulation group at the four-syllable nonword length. DISCUSSION: The findings suggest that targeting the speech motor component of nonword repetition through overt training and HD tDCS to the preSMA does not enhance phonological working memory ability.

Neural patterns elicited by lexical processing in adolescents with specific language impairment: support for the procedural deficit hypothesis?

BACKGROUND: Deficits in procedural memory have been proposed to account for the language deficits in specific language impairment (SLI). A key aspect of the procedural deficit hypothesis (PDH) account of SLI is that declarative memory is intact and functions as a compensatory mechanism in the acquisition of language in individuals with SLI. The current study examined the neural correlates of lexical-phonological and lexical-semantic processing with respect to these predictions in a group of adolescents with SLI with procedural memory impairment and a group of chronologically age-matched (CA) normal controls. METHODS: Participants completed tasks designed to measure procedural and declarative memory and two ERP tasks designed to assess lexical-semantic and lexical-phonological processing in the auditory modality. Procedural memory was assessed using a statistical learning task. Lexical-semantic processing was assessed using a sentence judgment task modulating semantic congruency and lexical-phonological processing was assessed using a word/nonword decision task modulating word frequency. Behavioral performance on the tasks, mean amplitude of the cortical response, and animated topographs were examined. RESULTS: Performance on the statistical word-learning task was at chance for the adolescents with SLI, whereas declarative memory was no different from the CA controls. Behavioral accuracy on the lexical-semantic task was the same for the adolescents with SLI and CA controls but accuracy on the lexical-phonological task was significantly poorer for the adolescents with SLI as compared to the CA controls. An N400 component was elicited in response to semantic congruency on the lexical-semantic task for both groups but differences were noted in both the location and time course of the cortical response for the SLI and CA groups. An N400 component was elicited by word frequency on the lexical-phonological task for the CA controls not for the adolescents with SLI. In contrast, post hoc analysis revealed a cortical response based on imageability for the adolescents with SLI, but not CA controls. Statistical word learning was significantly correlated with speed of processing on the lexical decision task for the CA controls but not for the adolescents with SLI. In contrast, statistical word learning ability was not correlated with the modulation of the N400 on either task for either group. CONCLUSION: The behavioral data suggests intact semantic conceptual knowledge, but impaired lexical phonological processing for the adolescents with SLI, consistent with the PDH. The pattern of cortical activation in response to semantic congruency and word frequency suggests, however, that the processing of lexical-semantic and lexical-phonological information by adolescents with a history of SLI may be supported by both overlapping and nonoverlapping neural generators to those of CA controls, and a greater reliance on declarative memory strategies. Taken together, the findings from this study suggest that the underlying representations of words in the lexicons of adolescents with a history of SLI may differ qualitatively from those of their typical peers, but these differences may only be evident when behavioral data and neural cortical patterns of activation are examined together.

Statistical word learning in Catalan-Spanish and English-speaking children with and without developmental language disorder.

BACKGROUND: A growing body of work shows that children with developmental language disorder (DLD) perform poorly on statistical word learning (SWL) tasks, consistent with the predictions of the Procedural Deficit Hypothesis that predicts that procedural memory is impaired in DLD. To date, however, SWL performance has not been compared across linguistically heterogeneous populations of children with DLD. AIMS: To compare SWL performance in a group of age, sex and non-verbal IQ-matched Catalan-Spanish and English-speaking children with and without DLD. METHODS & PROCEDURES: Two cohorts of children: (1) 35 Catalan-Spanish-speaking children with DLD (Mage = 8;7 years) and 35 age/sex-matched typical developing (TD) children (Mage = 8;9 years), and (2) 24 English-speaking children with DLD (Mage = 9;1 years) and 19 age/sex matched TD controls (Mage = 8;9 years) completed the tone version of a SWL task from Evans et al. (2009). Children listened to a tone language in which transitional probabilities within tone words were higher than those between words. OUTCOMES & RESULTS: For both Catalan-Spanish and English cohorts, overall performance for the children with DLD was poorer than that of the TD controls regardless of the child's native language. Item analysis revealed that children with DLD had difficulty tracking statistical information and using transitional probability to discover tone word boundaries within the input. For both the Catalan-Spanish and English-speaking children, SWL accounted for a significant amount of unique variance in Receptive and Expressive vocabulary. Likelihood ratio analysis revealed that for both Catalan-Spanish and English cohorts, children having performance ≤ 45% on the SWL task had an extremely high degree of likelihood of having DLD. The analysis also revealed that for the Catalan-Spanish and English-speaking children, scores of ≥ 75% and ≥ 70%, respectively, were highly likelihood to be children with normal language abilities. CONCLUSIONS & IMPLICATIONS: The findings add to a pattern suggesting that SWL is a mechanism that children rely on to acquire vocabulary. The results also suggest that SWL deficits, in particular when combined with other measures, may be a reliable diagnostic indicator for children with DLD regardless of the child's native language, and whether or not the child is bilingual or monolingual. WHAT THIS PAPER ADDS: What is already known on the subject Although there is some disagreement, a small but growing body of work suggests that deficits in procedural memory, as measured either by motor sequencing (Serial Reaction Time-SRT) or SWL tasks, may be part of the deficit profile of children with DLD. To date, studies have not examined SWL across linguistically heterogeneous populations of children with DLD to determine if it is a unique clinical marker of the disorder. What this paper adds to existing knowledge The results show that children with DLD, regardless of their native language, or whether the child is bi- or monolingual, have difficulties on SWL tasks, and that these deficits are linked to severity of the language disorder. Taken together, these results indicate that procedural memory deficits may be a core feature of DLD. This suggests that statistical-learning tasks using tone stimuli can also advance our understanding of statistical-learning abilities in children with DLD more globally. What are the potential or actual clinical implications of this work? The current study shows that statistical-learning tasks using tone stimuli can be used in conjunction with standardized assessment measures to differentiate children with DLD from children with typical language ability.

Cognitive Processes Related to Memory Capacity Explain Nearly All of the Variance in Language Test Performance in School-Age Children With and Without Developmental Language Disorder.

The purpose of this study was to investigate the dimensionality of the cognitive processes related to memory capacity and language ability and to assess the magnitude of the relationships among these processes in children developing typically (TD) and children with developmental language disorder (DLD). Participants were 234 children between the ages of 7;0 and 11;11 (117 TD and 117 DLD) who were propensity matched on age, sex, mother education and family income. Latent variables created from cognitive processing tasks and standardized measures of comprehension and production of lexical and sentential aspects of language were tested with confirmatory factor analysis (CFA) and structural regression. A five-factor CFA model that included the constructs of Fluid Intelligence, Controlled Attention, Working Memory, Long-Term Memory for Language Knowledge and Language Ability yielded better fit statistics than two four-factor nested models. The four cognitive abilities accounted for more than 92% of the variance in the language measures. A structural regression model indicated that the relationship between working memory and language ability was significantly greater for the TD group than the DLD group. These results are consistent with a broad conceptualization of the nature of language impairment in older, school-age children as encompassing a dynamic system in which cognitive abilities account for nearly all of the variance in linguistic abilities.

Toddlers' Ability to Leverage Statistical Information to Support Word Learning.

PURPOSE: This study investigated whether the ability to utilize statistical regularities from fluent speech and map potential words to meaning at 18-months predicts vocabulary at 18- and again at 24-months. METHOD: Eighteen-month-olds (N = 47) were exposed to an artificial language with statistical regularities within the speech stream, then participated in an object-label learning task. Learning was measured using a modified looking-while-listening eye-tracking design. Parents completed vocabulary questionnaires when their child was 18-and 24-months old. RESULTS: Ability to learn the object-label pairing for words after exposure to the artificial language predicted productive vocabulary at 24-months and amount of vocabulary change from 18- to 24 months, independent of non-verbal cognitive ability, socio-economic status (SES) and/or object-label association performance. CONCLUSION: Eighteen-month-olds' ability to use statistical information derived from fluent speech to identify words within the stream of speech and then to map the "words" to meaning directly predicts vocabulary size at 24-months and vocabulary change from 18 to 24 months. The findings support the hypothesis that statistical word segmentation is one of the important aspects of word learning and vocabulary acquisition in toddlers.

A New Memory Perspective on the Sentence Comprehension Deficits of School-Age Children With Developmental Language Disorder: Implications for Theory, Assessment, and Intervention.

Purpose The nature of the relationship between memory and sentence comprehension in school-age children with developmental language disorder (DLD) has been unclear. We present a novel perspective that highlights the relational influences of fluid intelligence, controlled attention, working memory (WM), and long-term memory (LTM) on sentence comprehension in children with and without DLD. This perspective has new and important implications for theory, assessment, and intervention. Method We review a large-scale study of children with and without DLD that focused on the connections between cognition, memory, and sentence comprehension. We also summarize a new model of these relationships. Results Our new model suggests that WM serves as a conduit through which syntactic knowledge in LTM, controlled attention, and general pattern recognition indirectly influence sentence comprehension in both children with DLD and typically developing children. For typically developing children, language-based LTM and fluid intelligence indirectly influence sentence comprehension. However, for children with DLD, controlled attention plays a larger indirect role. Conclusions WM plays a key role in children's ability to apply their syntactic knowledge when comprehending canonical and noncanonical sentences. Our new model has important implications for the assessment of sentence comprehension and for the treatment of larger sentence comprehension deficits.

Consistency of a Nonword Repetition Task to Discriminate Children with and without Developmental Language Disorder in Catalan-Spanish and European Portuguese Speaking Children.

Nonword repetition has been proposed as a diagnostic marker of developmental language disorder (DLD); however, the inconsistency in the ability of nonword repetition tasks (NRT) to identify children with DLD raises significant questions regarding its feasibility as a clinical tool. Research suggests that some of the inconsistency across NRT may be due to differences in the nature of the nonword stimuli. In this study, we compared children's performance on NRT between two cohorts: the children in the Catalan-Spanish cohort (CS) were bilingual, and the children in the European Portuguese cohort (EP) were monolingual. NRT performance was assessed in both Spanish and Catalan for the bilingual children from Catalonia-Spain and in Portuguese for the monolingual children from Portugal. Results show that although the absolute performance differed across the two cohorts, with NRT performance being lower for the CS, in both Catalan and Spanish, as compared to the EP cohort in both, the cut-points for the likelihood ratios (LH) were similar across the three languages and mirror those previously reported in previous studies. However, the absolute LH ratio values for this study were higher than those reported in prior research due in part to differences in wordlikeness and frequency of the stimuli in the current study. Taken together, the findings from this study show that an NRT consisting of 3-, 4-, and 5-syllable nonwords, which varies in wordlikeness ratings, when presented in a random order accurately identifies and correctly differentiates children with DLD from TD controls the child is bilingual or monolingual.

Tracking Changes in Frontal Lobe Hemodynamic Response in Individual Adults With Developmental Language Disorder Following HD tDCS Enhanced Phonological Working Memory Training: An fNIRS Feasibility Study.

Background: Current research suggests a neurobiological marker of developmental language disorder (DLD) in adolescents and young adults may be an atypical neural profile coupled with behavioral performance that overlaps with that of normal controls. Although many imaging techniques are not suitable for the study of speech and language processing in DLD populations, fNIRS may be a viable option. In this study we asked if fNIRS can be used to identify atypical cortical activation patterns in individual adults with DLD and track potential changes in cortical activation patterns following a phonological working memory training protocol enhanced with anodal HD tDCS stimulation to the presupplementary motor area (preSMA). Objective/Hypothesis: The purpose of this study was two-fold: (1) to determine if fNIRS can be used to identify atypical hemodynamic responses in individual young adults with DLD during active spoken word processing and, (2) to determine if fNIRS can detect changes in hemodynamic response in these same adults with DLD following anodal HD tDCS enhanced phonological working memory training. Methods: Two adult subjects with DLD (female, age 25) completed a total of two sessions of fNIRs working memory task prior to and following one session of a non-word repetition task paired with anodal HD tDCS (1.0 mA tDCS; 20 min) to the preSMA. Standardized z-scores of behavioral measures (accuracy and reaction time) and changes in hemodynamic response during an n-back working memory task for the two participants with DLD was compared to that of a normative sample of 21 age- and gender- matched normal controls (ages 18 to 25) prior to and following phonological working memory training. Results: Individual standardized z-scores for each participant with DLD indicated that prior to training, hemoglobin response in the prefrontal lobe for both participants was markedly different from each other and normal controls. Following training, standard scores showed that the hemodynamic response for both participants moved within normal limits for ROIs. Conclusion: These findings highlight the feasibility of fNIRS to establish individual differences in the link between behavior and neural patterns in single subjects with DLD, as well as track individual differences in changes in brain activity following working memory training.

A Comparison of the Storage-Only Deficit and Joint Mechanism Deficit Hypotheses of the Verbal Working Memory Storage Capacity Limitation of Children With Developmental Language Disorder.

Purpose The storage-only deficit and joint mechanism deficit hypotheses are 2 possible explanations of the verbal working memory (vWM) storage capacity limitation of school-age children with developmental language disorder (DLD). We assessed the merits of each hypothesis in a large group of children with DLD and a group of same-age typically developing (TD) children. Method Participants were 117 children with DLD and 117 propensity-matched TD children 7-11 years of age. Children completed tasks indexing vWM capacity, verbal short-term storage, sustained attention, attention switching, and lexical long-term memory (LTM). Results For the DLD group, all of the mechanisms jointly explained 26.5% of total variance. Storage accounted for the greatest portion (13.7%), followed by controlled attention (primarily sustained attention; 6.5%) and then lexical LTM (5.6%). For the TD group, all 3 mechanisms together explained 43.9% of total variance. Storage accounted for the most variance (19.6%), followed by lexical LTM (16.0%), sustained attention (5.4%), and attention switching (3.0%). There was a significant LTM × Group interaction, in which stronger LTM scores were associated with significantly higher vWM capacity scores for the TD group as compared to the DLD group. Conclusions Results support a joint mechanism deficit account of the vWM capacity limitation of children with DLD. Results provide substantively new insights into the underlying factors of the vWM capacity limitation in DLD. Supplemental Material https://doi.org/10.23641/asha.9932312.

Cognitive predictors of sentence comprehension in children with and without developmental language disorder: Implications for assessment and treatment.

Purpose: This paper summarises the clinical ramification of a large-scale study of the direct and indirect (mediated) influences of four cognitive mechanisms that are relevant to the comprehension of syntactic structure by school-age children with and without developmental language disorder (DLD). Method: A total of 117 children with DLD and 117 propensity-matched typically-developing (TD) children completed sentence comprehension tasks and cognitive tasks related to fluid reasoning, controlled attention, speed of processing, phonological short-term memory (pSTM), complex working memory (cWM) and language knowledge in long-term memory (LTM). Result: Results of confirmatory factor analysis (CFA) indicated that the most salient characteristics of cognitive processing in children with and without DLD were represented by a measurement model that included four latent variables: fluid reasoning, controlled attention, complex WM and language knowledge in LTM. Structural equation modelling (SEM) indicated that complex WM mediated the relationship between sentence comprehension and fluid reasoning, controlled attention and long-term memory for language knowledge. Conclusion: Our research suggests that the most salient characteristics of cognitive processing in children with and without DLD can be condensed to four cognitive factors: fluid reasoning, controlled attention, complex WM and language knowledge in LTM. We suggest a few measures that clinicians can use to reliably assess these factors, and we summarise a functional intervention programme that is designed to promote the strategic organisation of information in ways that challenge verbal complex WM and LTM processes that support language comprehension and use.

Effect of auditory status on visual emotion recognition in adolescents.

Adolescents with severe to profound hearing loss who wear cochlear implants (CIs) experience significantly more peer problems compared to peers with typical hearing (TH). Differences in peer social dynamics may relate to perception not only of message content, but also message intent based on a speaker's emotion from visual (e.g. facial expressions) and auditory (e.g. prosody) cues. Pediatric CI users may experience greater difficulty with auditory emotion recognition due to an impoverished signal representation provided by the device, but the effect of auditory status on visual emotion recognition yields conflicting results. OBJECTIVES: The current study examined accuracy and speed of visual emotion recognition in adolescents with CIs and peers with TH. METHODS: Participants included 58 adolescents (10-18 years) stratified by auditory status: 34 CI users and 24 TH peers. Participants identified the intended emotion (i.e. happiness, sadness, anger, fear, disgust, and surprise) of static images of faces displayed on a computer screen. RESULTS: No significant differences by auditory status emerged for response accuracy, response time to all trials, or response time to correct trials. Type of emotion significantly affected both accuracy and response time. CONCLUSION: Adolescents with CIs show similar accuracy and response time in recognizing static facial expressions compared to TH peers. Future studies should explore the association between visual emotion recognition and social well-being to determine the relationship between emotion recognition and overall quality of life in adolescents with CIs.

Word Frequency Is Associated With Cognitive Effort During Verbal Working Memory: A Functional Near Infrared Spectroscopy (fNIRS) Study.

PURPOSE: Psycholinguistic models traditionally view verbal working memory capacity as independent from linguistic features; connectionist models suggest otherwise. Moreover, lexical processing studies show high frequency words differ in cognitive effort from low frequency words, although these effects during concurrent processing of words in working memory are unknown. This novel study examines potential differences in cognitive effort, as measured by differences in HbO2 and Hb, for high frequency versus low frequency words during a working memory paradigm. METHODS: A total of 21 neurologically typical participants (age 18-23) completed an auditory, n-back, working memory task comparing performance with high- as compared to low- frequency words. Hemodynamic changes in the prefrontal cortex were recorded with a continuous-wave functional near-infrared spectroscopy (fNIRS) device. Behavioral data (accuracy, reaction time) were recorded using E-prime. RESULTS: Differences in word frequency were evident at both behavioral and neurological levels. Participants were more accurate, albeit slower in identifying the target two back in a sequence for low- as compared to high-frequency words. Patterns of hemodynamic changes were also significantly different between HF and LF conditions. CONCLUSION: The results from this study indicate that the behavioral and neurological signatures inherent in holding high- versus low-frequency words in working memory differs significantly. Specifically, the findings from this study indicated that words differing in frequency place different demands on cognitive processing load in memory updating tasks.

Patterns of structural lateralization in cortical language areas of older adolescents.

Structural lateralization of cortical language areas has been extensively studied in the past, with the conclusion that there is a predominant left lateralization in the majority of typically developing adolescents. However, lateralization in this age group has often been examined using cortical volumetric measures, without taking into account the independence of surface area and thickness. Utilizing structural MRI data in a relatively large sample size, the lateralization of cortical volume, surface area, and thickness was analysed across regions of interest (ROIs) known to support language processing in 118 typically developing adolescents, ages 13;9 to 18;9 using a laterality index. Results showed that the laterality index scores for volume and surface area were more strongly correlated than volume and thickness. Results also showed that not all language regions were left lateralized, with some ROIs being significantly right lateralized. Results also showed that surface area and thickness did not always share direction of lateralization. Taken together these results indicate that cortical ROIs supporting language are not all strongly left lateralized in adolescents. These data also show that cortical surface area and cortical thickness need to be treated independently in future studies characterizing language and lateralization in the adolescent brain.

Structural Relationship Between Cognitive Processing and Syntactic Sentence Comprehension in Children With and Without Developmental Language Disorder.

Purpose: We assessed the potential direct and indirect (mediated) influences of 4 cognitive mechanisms we believe are theoretically relevant to canonical and noncanonical sentence comprehension of school-age children with and without developmental language disorder (DLD). Method: One hundred seventeen children with DLD and 117 propensity-matched typically developing (TD) children participated. Comprehension was indexed by children identifying the agent in implausible sentences. Children completed cognitive tasks indexing the latent predictors of fluid reasoning (FLD-R), controlled attention (CATT), complex working memory (cWM), and long-term memory language knowledge (LTM-LK). Results: Structural equation modeling revealed that the best model fit was an indirect model in which cWM mediated the relationship among FLD-R, CATT, LTM-LK, and sentence comprehension. For TD children, comprehension of both sentence types was indirectly influenced by FLD-R (pattern recognition) and LTM-LK (linguistic chunking). For children with DLD, canonical sentence comprehension was indirectly influenced by LTM-LK and CATT, and noncanonical comprehension was indirectly influenced just by CATT. Conclusions: cWM mediates sentence comprehension in children with DLD and TD children. For TD children, comprehension occurs automatically through pattern recognition and linguistic chunking. For children with DLD, comprehension is cognitively effortful. Whereas canonical comprehension occurs through chunking, noncanonical comprehension develops on a word-by-word basis. Supplemental Material: https://doi.org/10.23641/asha.7178939.

Cognitive Predictors of Spoken Word Recognition in Children With and Without Developmental Language Disorders.

Purpose: This study examined the influence of cognitive factors on spoken word recognition in children with developmental language disorder (DLD) and typically developing (TD) children. Method: Participants included 234 children (aged 7;0-11;11 years;months), 117 with DLD and 117 TD children, propensity matched for age, gender, socioeconomic status, and maternal education. Children completed a series of standardized assessment measures, a forward gating task, a rapid automatic naming task, and a series of tasks designed to examine cognitive factors hypothesized to influence spoken word recognition including phonological working memory, updating, attention shifting, and interference inhibition. Results: Spoken word recognition for both initial and final accept gate points did not differ for children with DLD and TD controls after controlling target word knowledge in both groups. The 2 groups also did not differ on measures of updating, attention switching, and interference inhibition. Despite the lack of difference on these measures, for children with DLD, attention shifting and interference inhibition were significant predictors of spoken word recognition, whereas updating and receptive vocabulary were significant predictors of speed of spoken word recognition for the children in the TD group. Conclusion: Contrary to expectations, after controlling for target word knowledge, spoken word recognition did not differ for children with DLD and TD controls; however, the cognitive processing factors that influenced children's ability to recognize the target word in a stream of speech differed qualitatively for children with and without DLDs.

"Whatdunit?" Sentence Comprehension Abilities of Children With SLI: Sensitivity to Word Order in Canonical and Noncanonical Structures.

PURPOSE: With Aim 1, we compared the comprehension of and sensitivity to canonical and noncanonical word order structures in school-age children with specific language impairment (SLI) and same-age typically developing (TD) children. Aim 2 centered on the developmental improvement of sentence comprehension in the groups. With Aim 3, we compared the comprehension error patterns of the groups. METHOD: Using a "Whatdunit" agent selection task, 117 children with SLI and 117 TD children (ages 7:0-11:11, years:months) propensity matched on age, gender, mother's education, and family income pointed to the picture that best represented the agent in semantically implausible canonical structures (subject-verb-object, subject relative) and noncanonical structures (passive, object relative). RESULTS: The SLI group performed worse than the TD group across sentence types. TD children demonstrated developmental improvement across each sentence type, but children with SLI showed improvement only for canonical sentences. Both groups chose the object noun as agent significantly more often than the noun appearing in a prepositional phrase. CONCLUSIONS: In the absence of semantic-pragmatic cues, comprehension of canonical and noncanonical sentences by children with SLI is limited, with noncanonical sentence comprehension being disproportionately limited. The children's ability to make proper semantic role assignments to the noun arguments in sentences, especially noncanonical, is significantly hindered.

Relations between patterning skill and differing aspects of early mathematics knowledge.

Patterns are often considered central to early mathematics learning; yet, the empirical evidence linking early pattern knowledge to mathematics performance is sparse. In the current study, 36 children ranging in age from 5 to 13 years old (M = 9.1 years) completed a pattern extension task with three pattern types that varied in difficulty. They also completed three math tasks that tapped calculation skill and knowledge of concepts. Children were successful on the pattern extension task, though older children fared better than younger children, potentially due in part to their explanations that considered both dimensions of the pattern (shape and size). Importantly, success on the pattern extension task was related to mathematics performance. After controlling for age and verbal working memory, patterning skill predicted calculation skill; however, patterning skill was not associated with knowledge of concepts. Results suggest that patterning may play a key role in the development of some aspects of early mathematics knowledge.

Syntactic Versus Memory Accounts of the Sentence Comprehension Deficits of Specific Language Impairment: Looking Back, Looking Ahead.

Purpose: Compared with same-age typically developing peers, school-age children with specific language impairment (SLI) exhibit significant deficits in spoken sentence comprehension. They also demonstrate a range of memory limitations. Whether these 2 deficit areas are related is unclear. The present review article aims to (a) review 2 main theoretical accounts of SLI sentence comprehension and various studies supporting each and (b) offer a new, broader, more integrated memory-based framework to guide future SLI research, as we believe the available evidence favors a memory-based perspective of SLI comprehension limitations. Method: We reviewed the literature on the sentence comprehension abilities of English-speaking children with SLI from 2 theoretical perspectives. Results: The sentence comprehension limitations of children with SLI appear to be more fully captured by a memory-based perspective than by a syntax-specific deficit perspective. Conclusions: Although a memory-based view appears to be the better account of SLI sentence comprehension deficits, this view requires refinement and expansion. Current memory-based perspectives of adult sentence comprehension, with proper modification, offer SLI investigators new, more integrated memory frameworks within which to study and better understand the sentence comprehension abilities of children with SLI.

A Proof of Concept Study of Function-Based Statistical Analysis of fNIRS Data: Syntax Comprehension in Children with Specific Language Impairment Compared to Typically-Developing Controls.

Functional near infrared spectroscopy (fNIRS) is a neuroimaging technology that enables investigators to indirectly monitor brain activity in vivo through relative changes in the concentration of oxygenated and deoxygenated hemoglobin. One of the key features of fNIRS is its superior temporal resolution, with dense measurements over very short periods of time (100 ms increments). Unfortunately, most statistical analysis approaches in the existing literature have not fully utilized the high temporal resolution of fNIRS. For example, many analysis procedures are based on linearity assumptions that only extract partial information, thereby neglecting the overall dynamic trends in fNIRS trajectories. The main goal of this article is to assess the ability of a functional data analysis (FDA) approach for detecting significant differences in hemodynamic responses recorded by fNIRS. Children with and without SLI wore two, 3 × 5 fNIRS caps situated over the bilateral parasylvian areas as they completed a language comprehension task. FDA was used to decompose the high dimensional hemodynamic curves into the mean function and a few eigenfunctions to represent the overall trend and variation structures over time. Compared to the most popular GLM, we did not assume any parametric structure and let the data speak for itself. This analysis identified significant differences between the case and control groups in the oxygenated hemodynamic mean trends in the bilateral inferior frontal and left inferior posterior parietal brain regions. We also detected significant group differences in the deoxygenated hemodynamic mean trends in the right inferior posterior parietal cortex and left temporal parietal junction. These findings, using dramatically different approaches, experimental designs, data sets, and foci, were consistent with several other reports, confirming group differences in the importance of these two areas for syntax comprehension. The proposed FDA was consistent with the temporal characteristics of fNIRS, thus providing an alternative methodology for fNIRS analyses.

Semantic Structure in Vocabulary Knowledge Interacts With Lexical and Sentence Processing in Infancy.

Although the size of a child's vocabulary associates with language-processing skills, little is understood regarding how this relation emerges. This investigation asks whether and how the structure of vocabulary knowledge affects language processing in English-learning 24-month-old children (N = 32; 18 F, 14 M). Parental vocabulary report was used to calculate semantic density in several early-acquired semantic categories. Performance on two language-processing tasks (lexical recognition and sentence processing) was compared as a function of semantic density. In both tasks, real-time comprehension was facilitated for higher density items, whereas lower density items experienced more interference. The findings indicate that language-processing skills develop heterogeneously and are influenced by the semantic network surrounding a known word.