Brain Event-Related Potentials (ERPs) Measured at Birth Predict Later Language Development in Children with and Without Familial Risk for Dyslexia

Infant neural speech encoding is associated with pre-reading skill development

OBJECTIVE

We longitudinally investigated whether infant P1 and N2 ERPs recorded in newborns and at 28 months could predict pre-reading skills at 28 months and 4-5 years.

METHODS

We recorded ERPs to a pseudoword in newborns and at 28 months in a sample over-represented by infants with familial dyslexia risk. Using multiple linear regression models, we examined P1 and N2 associations with pre-reading skills at 28 months and 4-5 years.

RESULTS

Shorter latencies of the newborn P1 predicted faster serial naming at 28 months. Larger amplitudes and shorter latencies of P1 at 28 months predicted better serial naming abilities and auditory working memory across the pre-reading stage. Right-lateralized P1 and N2 were related to poorer pre-reading skills.

CONCLUSIONS

Infant ERPs, particularly P1, providing information about neural speech encoding abilities, are associated with pre-reading skill development.

SIGNIFICANCE

Infant and early childhood neural speech encoding abilities may work as early predictive markers of reading development and impairment. This study may help to plan early interventions targeting phonological processing to prevent or ameliorate learning deficits.

Infant mismatch responses to speech-sound changes predict language development in preschoolers at risk for dyslexia

OBJECTIVE

We investigated how infant mismatch responses (MMRs), which have the potential for providing information on auditory discrimination abilities, could predict subsequent development of pre-reading skills and the risk for familial dyslexia.

METHODS

We recorded MMRs to vowel, duration, and frequency deviants in pseudo-words at birth and 28 months in a sample over-represented by infants with dyslexia risk. We examined MMRs' associations with pre-reading skills at 28 months and 4-5 years and compared the results in subgroups with vs. without dyslexia risk.

RESULTS

Larger positive MMR (P-MMR) at birth was found to be associated with better serial naming. In addition, increased mismatch negativity (MMN) and late discriminative negativity (LDN), and decreased P-MMR at 28 months overall, were shown to be related to better pre-reading skills. The associations were influenced by dyslexia risk, which was also linked to poor pre-reading skills.

CONCLUSIONS

Infant MMRs, providing information about the maturity of the auditory system, are associated with the development of pre-reading skills. Speech-processing deficits may contribute to deficits in language acquisition observed in dyslexia.

SIGNIFICANCE

Infant MMRs could work as predictive markers of atypical linguistic development during early childhood. Results may help in planning preventive and rehabilitation interventions in children at risk of learning impairments.

Associations between EEG power and coherence with cognition and early precursors of speech and language development across the first months of life

The neural processes underpinning cognition and language development in infancy are of great interest. We investigated EEG power and coherence in infancy, as a reflection of underlying cortical function of single brain region and cross-region connectivity, and their relations to cognition and early precursors of speech and language development. EEG recordings were longitudinally collected from 21 infants with typical development between approximately 1 and 7 months. We investigated relative band power at 3-6Hz and 6-9Hz and EEG coherence of these frequency ranges at 25 electrode pairs that cover key brain regions. A correlation analysis was performed to assess the relationship between EEG measurements across frequency bands and brain regions and raw Bayley cognitive and language developmental scores. In the first months of life, relative band power is not correlated with cognitive and language scales. However, 3-6Hz coherence is negatively correlated with receptive language scores between frontoparietal regions, and 6-9Hz coherence is negatively correlated with expressive language scores between frontoparietal regions. The results from this preliminary study contribute to the existing literature on the relationship between electrophysiological development, cognition, and early speech precursors in this age group. Future work should create norm references of early development in these domains that can be compared with infants at risk for neurodevelopmental disabilities.

Leveraging brain science for impactful advocacy and policymaking: The synergistic partnership between developmental cognitive neuroscientists and a parent-led grassroots movement to drive dyslexia prevention policy and legislation

Reading proficiency is crucial for academic, vocational, and economic success and has been closely linked to health outcomes. Unfortunately, in the United States, a concerning 63% of fourth-grade children are reading below grade level, with approximately 7%-10% exhibiting a disability in word reading, developmental dyslexia. Research in developmental cognitive neuroscience indicates that individuals with dyslexia show functional and structural brain alterations in regions processing reading and reading-related information, with some of these differences emerging as early as preschool and even infancy. This suggests that some children start schooling with less optimal brain architecture for learning to read, emphasizing the need for preventative education practices. This article reviews educational policies impacting children with dyslexia and highlights a decentralized parent-led grassroots movement, Decoding Dyslexia, which centers the voices of those directly impacted by dyslexia. It utilizes civic engagement practices, advocacy and lobbying on local, federal, and social media platforms, and strong partnerships with scientists to drive systems-level change in educational practices, leading to dyslexia prevention legislation across the U.S. The ongoing partnership continues to address the profound gaps between scientific findings and policymaking to drive systems-level change for contemporary challenges in educational practices within a learning disabilities framework.

Cortical Auditory Evoked Potential Testing in Children With Auditory Neuropathy Spectrum Disorder

PURPOSE

In the present report, we reviewed the role of cortical auditory evoked potentials (CAEPs) as an objective measure during the evaluation and management process in children with auditory neuropathy spectrum disorder (ANSD).

METHOD

We reviewed the results of CAEP recordings in 66 patients with ANSD aged between 2 months and 12 years and assessed the relationship between their characteristics (prevalence, morphology, latencies, and amplitudes) and various clinical features, including the mode of medical management.

RESULTS

Overall, the CAEPs were present in 85.2% of the ears tested. Factors such as prematurity, medical complexity, neuronal issues, or presence of syndromes did not have an effect on the presence or absence of CAEPs. CAEP latencies were significantly shorter in ears with cochlear nerve deficiency than in ears with a normal caliber nerve. Three different patterns of CAEP responses were observed in patients with bilateral ANSD and present cochlear nerves: (a) responses with normal morphology and presence of both P1-P2complex and N2 components, (b) responses with abnormal morphology and presence of the N2 component but undefined P1-P2complex peak, and (c) entirely absent responses. None of the patients with normal, mild, or moderate degree of hearing loss had a complete absence of CAEP responses. No significant differences were uncovered when comparing the latencies across unaided and aided children and children who later received cochlear implants.

CONCLUSIONS

The CAEP protocol used in our ANSD program did inform about the presence or absence of central auditory stimulation. Absent responses typically fit into an overall picture of complete auditory deprivation and all of these children were ultimately offered cochlear implants after failing to develop oral language. Present responses, on the other hand, were acknowledged as a sign of some degree of auditory stimulation but always interpreted with caution given that prognostic implications remain unclear.

Intergenerational longitudinal associations between parental reading/musical traits, infants' auditory processing, and later phonological awareness skills

The intergenerational transmission of language/reading skills has been demonstrated by evidence reporting that parental literacy abilities contribute to the prediction of their offspring's language and reading skills. According to the "Intergenerational Multiple Deficit Model," literacy abilities of both parents are viewed as indicators of offspring's liability for literacy difficulties, since parents provide offspring with genetic and environmental endowment. Recently, studies focusing on the heritability of musical traits reached similar conclusions. The "Musical Abilities, Pleiotropy, Language, and Environment (MAPLE)" framework proposed that language/reading and musical traits share a common genetic architecture, and such shared components have an influence on the heritable neural underpinnings of basic-level skills underlying musical and language traits. Here, we investigate the intergenerational transmission of parental musical and language-related (reading) abilities on their offspring's neural response to a basic auditory stimulation (neural intermediate phenotype) and later phonological awareness skills, including in this complex association pattern the mediating effect of home environment. One-hundred and seventy-six families were involved in this study. Through self-report questionnaires we assessed parental reading abilities and musicality, as well as home literacy and musical environment. Offspring were involved in a longitudinal study: auditory processing was measured at 6  months of age by means of a Rapid Auditory Processing electrophysiological paradigm, and phonological awareness was assessed behaviorally at 5  years of age. Results reveal significant correlations between parents' reading skills and musical traits. Intergenerational associations were investigated through mediation analyses using structural equation modeling. For reading traits, the results revealed that paternal reading was indirectly associated with children's phonological awareness skills via their electrophysiological MisMatch Response at 6  months, while maternal reading was directly associated with children's phonological awareness. For musical traits, we found again that paternal musicality, rather than maternal characteristics, was associated with children's phonological phenotypes: in this case, the association was mediated by musical environment. These results provide some insight about the intergenerational pathways linking parental reading and musical traits, neural underpinnings of infants' auditory processing and later phonological awareness skills. Besides shedding light on possible intergenerational transmission mechanisms, this study may open up new perspectives for early intervention based on environmental enrichment.

The Role of Visual Factors in Dyslexia

What are the causes of dyslexia? Decades of research reflect a determined search for a single cause where a common assumption is that dyslexia is a consequence of problems with converting phonological information into lexical codes. But reading is a highly complex activity requiring many well-functioning mechanisms, and several different visual problems have been documented in dyslexic readers. We critically review evidence from various sources for the role of visual factors in dyslexia, from magnocellular dysfunction through accounts based on abnormal eye movements and attentional processing, to recent proposals that problems with high-level vision contribute to dyslexia. We believe that the role of visual problems in dyslexia has been underestimated in the literature, to the detriment of the understanding and treatment of the disorder. We propose that rather than focusing on a single core cause, the role of visual factors in dyslexia fits well with risk and resilience models that assume that several variables interact throughout prenatal and postnatal development to either promote or hinder efficient reading.

Neural phoneme discrimination in variable speech in newborns - Associations with dyslexia risk and later language skills

A crucial skill in infant language acquisition is learning of the native language phonemes. This requires the ability to group complex sounds into distinct auditory categories based on their shared features. Problems in phonetic learning have been suggested to underlie language learning difficulties in dyslexia, a developmental reading-skill deficit. We investigated auditory abilities important for language acquisition in newborns with or without a familial risk for dyslexia with electrophysiological mismatch responses (MMRs). We presented vowel changes in a sequence of acoustically varying vowels, requiring grouping of the stimuli to two phoneme categories. The vowel changes elicited an MMR which was significantly diminished in infants whose parents had the most severe dyslexia in our sample. Phoneme-MMR amplitude and its hemispheric lateralization were associated with language test outcomes assessed at 28 months, an age at which it becomes possible to behaviourally test children and several standardized tests are available. In addition, statistically significant MMRs to violations of a complex sound-order rule were only found in infants without dyslexia risk, but these results are very preliminary due to small sample size. The results demonstrate the relevance of the newborn infants' readiness for phonetic learning for their emerging language skills. Phoneme extraction difficulties in infants at familial risk may contribute to the phonological deficits observed in dyslexia.

Decoding of speech information using EEG in children with dyslexia: Less accurate low-frequency representations of speech, not "Noisy" representations

The amplitude envelope of speech carries crucial low-frequency acoustic information that assists linguistic decoding. The sensory-neural Temporal Sampling (TS) theory of developmental dyslexia proposes atypical encoding of speech envelope information < 10 Hz, leading to atypical phonological representations. Here a backward linear TRF model and story listening were employed to estimate the speech information encoded in the electroencephalogram in the canonical delta, theta and alpha bands by 9-year-old children with and without dyslexia. TRF decoding accuracy provided an estimate of how faithfully the children's brains encoded low-frequency envelope information. Between-group analyses showed that the children with dyslexia exhibited impaired reconstruction of speech information in the delta band. However, when the quality of speech encoding for each child was estimated using child-by-child decoding models, then the dyslexic children did not differ from controls. This suggests that children with dyslexia encode neither "noisy" nor "normal" representations of the speech signal, but different representations.

Researcher-practitioner partnerships and in-school laboratories facilitate translational research in reading

Educational neuroscience approaches have helped to elucidate the brain basis of Reading Disability (RD) and of reading intervention response; however, there is often limited translation of this knowledge to the broader scientific and educational communities. Moreover, this work is traditionally lab-based, and thus the underlying theories and research questions are siloed from classroom practices. With growing awareness of the neurobiological origins of RD and increasing popularity of putative "brain-based" approaches in clinics and classrooms, it is imperative that we create more direct and bidirectional communication between scientists and practitioners. Such direct collaborations can help dispel neuromyths, and lead to increased understanding of the promises and pitfalls of neuroscience approaches. Moreover, direct partnerships between researchers and practitioners can lead to greater ecological validity in study designs to improve upon the translational potential of findings. To this end, we have forged collaborative partnerships, and built cognitive neuroscience laboratories within independent reading disabilities schools. This approach affords frequent and ecologically valid neurobiological assessment as children's reading improves in response to intervention. It also permits the creation of dynamic models of leading and lagging relationships of students' learning, and identification of individual-level predictors of intervention response. The partnerships also provide in-depth knowledge of student characteristics and classroom practices, which, when combined with the data we acquire, may facilitate optimization of instructional approaches. In this commentary, we discuss the creation of our partnerships, the scientific problem we are addressing (variable response to reading intervention), and the epistemological significance of researcher-practitioner bi-directional learning.

Eye tracking based assessment of lexical processing and early lexical development in very preterm children

BACKGROUND

Associations between lexical processing and lexical development during the second year of life have been little studied in preterm children.

AIMS

To evaluate associations between lexical processing at 18 months and lexical development between 12 and 18 months in very preterm children.

STUDY DESIGN

Correlational study.

SUBJECTS

25 Finnish-speaking children born <32 gestational weeks.

OUTCOME MEASURES

Lexical processing (reaction time RT; correct looking time CLT) was measured with an eye tracking technology-based task at 18 months' corrected age. Lexical development was measured longitudinally at 12-, 15- and 18-months' corrected age using the following screening instruments: the short form version of the MacArthur Communicative Development Inventories and the Communication and Symbolic Behavior Scale: Infant-Toddler Checklist.

RESULTS

The longer the RT of the child, the weaker expressive skills the child had at 12 and 15 months (correlations coefficient values -0.45 to -0.51). The more the child looked at the target image compared to the distractor (CLT), the stronger expressive skills the child had at 18 months (r = 0.45-0.52). A linear regression model with RT and gender as independent variables explained 33 % of the variance in lexical skills at 18 months. A model with CLT explained 40 % of expressive skills at 18 months.

CONCLUSIONS

Lexical processing at 18 months was associated with expressive lexical development in very preterm children. The results suggest eye tracking technology based methods may have utility in the assessment of early lexical growth in preterm children, although further research is needed to assess psychometric properties and predictive value of the method.

Development of Atypical Reading at Ages 5 to 9 Years and Processing of Speech Envelope Modulations in the Brain

Different studies have suggested that during speech processing readers with dyslexia present atypical levels of neural entrainment as well as atypical functional hemispherical asymmetries in comparison with typical readers. In this study, we evaluated these differences in children and the variation with age before and after starting with formal reading instruction. Synchronized neural auditory processing activity was quantified based on auditory steady-state responses (ASSRs) from EEG recordings. The stimulation was modulated at syllabic and phonemic fluctuation rates present in speech. We measured the brain activation patterns and the hemispherical asymmetries in children at three age points (5, 7, and 9 years old). Despite the well-known heterogeneity during developmental stages, especially in children and in dyslexia, we could extract meaningful common oscillatory patterns. The analyses included (1) the estimations of source localization, (2) hemispherical preferences using a laterality index, measures of neural entrainment, (3) signal-to-noise ratios (SNRs), and (4) connectivity using phase coherence measures. In this longitudinal study, we confirmed that the existence of atypical levels of neural entrainment and connectivity already exists at pre-reading stages. Overall, these measures reflected a lower ability of the dyslectic brain to synchronize with syllabic rate stimulation. In addition, our findings reinforced the hypothesis of a later maturation of the processing of beta rhythms in dyslexia. This investigation emphasizes the importance of longitudinal studies in dyslexia, especially in children, where neural oscillatory patterns as well as differences between typical and atypical developing children can vary in the span of a year.

Neural detection of changes in amplitude rise time in infancy

Amplitude rise times play a crucial role in the perception of rhythm in speech, and reduced perceptual sensitivity to differences in rise time is related to developmental language difficulties. Amplitude rise times also play a mechanistic role in neural entrainment to the speech amplitude envelope. Using an ERP paradigm, here we examined for the first time whether infants at the ages of seven and eleven months exhibit an auditory mismatch response to changes in the rise times of simple repeating auditory stimuli. We found that infants exhibited a mismatch response (MMR) to all of the oddball rise times used for the study. The MMR was more positive at seven than eleven months of age. At eleven months, there was a shift to a mismatch negativity (MMN) that was more pronounced over left fronto-central electrodes. The MMR over right fronto-central electrodes was sensitive to the size of the difference in rise time. The results indicate that neural processing of changes in rise time is present at seven months, supporting the possibility that early speech processing is facilitated by neural sensitivity to these important acoustic cues.

Cortical auditory evoked potentials in 1-month-old infants predict language outcomes at 12 months

The neurophysiological assessment of infants in their first developmental year can provide important information about the functional changes of the brain and supports the study of behavioral and developmental characteristics. Infants' cortical auditory evoked potentials (CAEPs) reflect cortical maturation and appear to predict subsequent language abilities. This study aimed to identify CAEP components to two auditory stimulus intensities in 1-month-old infants and to understand how these are associated with social interactive and self-regulatory behaviors. In addition, it examined whether CAEPs predicted developmental outcomes when infants were assessed at 12 months of age. At 1 month, P2 and N2 components were present for both auditory stimulus intensities, with an increased P2 amplitude being observed for the higher-intensity stimuli. We also observed that an increased P2 amplitude in the lower intensity predicted receptive and expressive language competencies at 12 months. These results are consistent with previous findings indicating an association between auditory processing and developmental outcomes in infants. This study suggests that specific auditory neurophysiological markers are associated with developmental outcomes in the first developmental year.

Predicting Reading From Behavioral and Neural Measures - A Longitudinal Event-Related Potential Study

Fluent reading is characterized by fast and effortless decoding of visual and phonological information. Here we used event-related potentials (ERPs) and neuropsychological testing to probe the neurocognitive basis of reading in a sample of children with a wide range of reading skills. We report data of 51 children who were measured at two time points, i.e., at the end of first grade (mean age 7.6 years) and at the end of fourth grade (mean age 10.5 years). The aim of this study was to clarify whether next to behavioral measures also basic unimodal and bimodal neural measures help explaining the variance in the later reading outcome. Specifically, we addressed the question of whether next to the so far investigated unimodal measures of N1 print tuning and mismatch negativity (MMN), a bimodal measure of audiovisual integration (AV) contributes and possibly enhances prediction of the later reading outcome. We found that the largest variance in reading was explained by the behavioral measures of rapid automatized naming (RAN), block design and vocabulary (46%). Furthermore, we demonstrated that both unimodal measures of N1 print tuning (16%) and filtered MMN (7%) predicted reading, suggesting that N1 print tuning at the early stage of reading acquisition is a particularly good predictor of the later reading outcome. Beyond the behavioral measures, the two unimodal neural measures explained 7.2% additional variance in reading, indicating that basic neural measures can improve prediction of the later reading outcome over behavioral measures alone. In this study, the AV congruency effect did not significantly predict reading. It is therefore possible that audiovisual congruency effects reflect higher levels of multisensory integration that may be less important for reading acquisition in the first year of learning to read, and that they may potentially gain on relevance later on.

Common Misconceptions about the Phonological Deficit Theory of Dyslexia

In this discussion paper, I review a number of common misconceptions about the phonological deficit theory (PDH) of dyslexia. These include the common but mistaken idea that the PDH is simply about phonemic awareness (PA), and, consequently, is a circular “pseudo”-explanation or epiphenomenon of reading difficulties. I argue that PA is only the “tip of the phonological iceberg” and that “deeper” spoken-language phonological impairments among dyslexics appear well before the onset of reading and even at birth. Furthermore, not even reading-specific expressions of phonological deficits—PA or pseudoword naming, can be considered circular if we clearly distinguish between reading proper—real meaning-bearing words, or real text, and the mechanisms (subskills) of reading development (such as phonological recoding). I also explain why an understanding of what constitutes an efficient writing system explains why phonology is necessarily a major source of variability in reading ability and hence a core deficit (or at least one core deficit) among struggling readers whether dyslexic or non-dyslexic. I also address the misguided notion that the PDH has now fallen out of favor because most dyslexia researchers have (largely) ceased studying phonological processing. I emphasize that acceptance of the PDH does not imply repudiation of other non-phonological hypotheses because the PDH does not claim to account for all the variance in reading ability/disability. Finally, I ask where neurobiology enters the picture and suggest that researchers need to exercise more caution in drawing their conclusions.

Speech Processing in Autism Spectrum Disorder: An Integrative Review of Auditory Neurophysiology Findings

Purpose Investigations into the nature of communication disorders in autistic individuals increasingly evaluate neural responses to speech stimuli. This integrative review aimed to consolidate the available data related to speech and language processing across levels of stimulus complexity (from single speech sounds to sentences) and to relate it to the current theories of autism. Method An electronic database search identified peer-reviewed articles using event-related potentials or magnetoencephalography to investigate auditory processing from single speech sounds to sentences in autistic children and adults varying in language and cognitive abilities. Results Atypical neural responses in autistic persons became more prominent with increasing stimulus and task complexity. Compared with their typically developing peers, autistic individuals demonstrated mostly intact sensory responses to single speech sounds, diminished spontaneous attentional orienting to spoken stimuli, specific difficulties with categorical speech sound discrimination, and reduced processing of semantic content. Atypical neural responses were more often observed in younger autistic participants and in those with concomitant language disorders. Conclusions The observed differences in neural responses to speech stimuli suggest that communication difficulties in autistic individuals are more consistent with the reduced social interest than the auditory dysfunction explanation. Current limitations and future directions for research are also discussed.

Portable Acquisition of Auditory ERPs: A Pilot Study of Premature Infants

BACKGROUND

Prior work suggests that event-related potential (ERP) studies in infancy may help predict developmental outcome.

METHODS

As part of a longitudinal study of early child development, we used the auditory oddball stimulus paradigm with a portable electroencephalography system to obtain ERP data from two-month-old infants (32 term, six preterm) in Sri Lanka. The mismatch negativity was calculated between 200 and 350 milliseconds after stimulus presentation.

RESULTS

We found a significant correlation between birth weight and mismatch negativity (P = 0.046), and our time-frequency analysis indicated power differences between standard and oddball tones at approximately 5 and 18 Hz. There was no significant difference between mismatch negativity in children undergoing ERP studies in a hospital setting (30) versus in the child's home (eight).

CONCLUSIONS

Although our modest sample size precludes drawing definitive conclusions, these preliminary results show that it is possible to acquire ERP datasets using currently available portable technology in a hospital or home setting, even in a developing nation such as Sri Lanka. Follow-up of this cohort will include developmental assessments, which will add to the growing literature relating early electrophysiology to developmental outcome.

Modulation of Theta Phase Synchrony during Syllable Processing as a Function of Interactive Acoustic Experience in Infancy

Plasticity, a prominent characteristic of the infant brain, supports formation of cortical representations as infants begin to interact with and adapt to environmental sensory events. Enhanced acoustic processing efficiency along with improved allocation of attentional resources at 7 months and establishment of well-defined phonemic maps at 9 months have been shown to be facilitated by early interactive acoustic experience (IAE). In this study, using an oddball paradigm and measures of theta phase synchrony at source level, we examined short- and long-term effects of nonspeech IAE on syllable processing. Results demonstrated that beyond maturation alone, IAE increased the efficiency of syllabic representation and discrimination, an effect that endured well beyond the immediate training period. As compared with naive controls, the IAE-trained group at 7, 9, and 18 months showed less theta phase synchrony for the standard syllable and at 7 and 18 months for the deviant syllable. The decreased theta phase synchrony exhibited by the trained group suggests more mature, efficient, acoustic processing, and thus, better cortical representation and discrimination of syllabic content. Further, the IAE modulatory effect observed on theta phase synchrony in left auditory cortex at 7 and 9 months was differentially associated with receptive and expressive language scores at 12 and 18 months of age.

Functional Connectivity in Infancy and Toddlerhood Predicts Long-Term Language and Preliteracy Outcomes

Functional connectivity (FC) techniques can delineate brain organization as early as infancy, enabling the characterization of early brain characteristics associated with subsequent behavioral outcomes. Previous studies have identified specific functional networks in infant brains that underlie cognitive abilities and pathophysiology subsequently observed in toddlers and preschoolers. However, it is unknown whether and how functional networks emerging within the first 18 months of life contribute to the development of higher order, complex functions of language/literacy at school-age. This 5-year longitudinal imaging project starting in infancy, utilized resting-state functional magnetic resonance imaging and demonstrated prospective associations between FC in infants/toddlers and subsequent language and foundational literacy skills at 6.5 years old. These longitudinal associations were shown independently of key environmental influences and further present in a subsample of infant imaging data (≤12 months), suggesting early emerged functional networks specifically linked to high-order language and preliteracy skills. Moreover, emergent language skills in infancy and toddlerhood contributed to the prospective associations, implicating a role of early linguistic experiences in shaping the FC correlates of long-term oral language skills. The current results highlight the importance of functional organization established in infancy and toddlerhood as a neural scaffold underlying the learning process of complex cognitive functions.

White matter in infancy is prospectively associated with language outcomes in kindergarten

Language acquisition is of central importance to child development. Although this developmental trajectory is shaped by experience postnatally, the neural basis for language emerges prenatally. Thus, a fundamental question remains: do structural foundations for language in infancy predict long-term language abilities? Longitudinal investigation of 40 children from infancy to kindergarten reveals that white matter in infancy is prospectively associated with subsequent language abilities, specifically between: (i) left arcuate fasciculus and phonological awareness and vocabulary knowledge, (ii) left corticospinal tract and phonological awareness, and bilateral corticospinal tract with phonological memory; controlling for age, cognitive, and environmental factors. Findings link white matter in infancy with school-age language abilities, suggesting that white matter organization in infancy sets a foundation for long-term language development.

The validity of the Language Environment Analysis system in two neonatal intensive care units

AIM

To evaluate the validity of the Language Environment Analysis (LENA) system's automatic measures in two neonatal intensive care units supporting parent-infant closeness, and in two Finno-Ugric languages: Finnish and Estonian.

METHODS

The sound environment of 70 very preterm infants was recorded for 16 h in the neonatal intensive care units with the LENA system roughly at the gestational age of 32 (+2) weeks. Of these, the recordings of 14 infants (20%, two 5-min samples with a high percentage of speech, totally 140 min) were analysed in detail and in two different ways. Parental closeness diaries were used to document the presence of the parents. Agreements between LENA system and human coder estimates were analysed.

RESULTS

Findings showed a high variation in agreements. The highest agreements were found in female and adult word counts (r = 0.91 and 0.95). The agreements for child vocalisation count, conversational turns and silence were modest or low (r = -0.03 to 0.64).

CONCLUSION

Our study provides novel information on the validity of the LENA system in the neonatal intensive care unit. Findings show that the LENA system provides valid information on adult words, but LENA estimates for child vocalisations were less valid at this early age.

ERP Mismatch Negativity Amplitude and Asymmetry Reflect Phonological and Rapid Automatized Naming Skills in English-Speaking Kindergartners

The mismatch negativity (MMN), an electrophysiological response to an oddball auditory stimulus, is related to reading ability in many studies. There are conflicting findings regarding exactly how the MMN relates to risk or actual diagnosis of dyslexia/reading impairment, perhaps due to the heterogeneity of abilities in children with reading impairment. In this study, 166 English-speaking kindergarten children oversampled for dyslexia risk completed behavioral assessments and a speech-syllable MMN paradigm. We examined how early and late MMN mean amplitude and laterality were related to two established predictors of reading ability: phonological awareness (PA) and rapid automatized naming (RAN). In bootstrapped group analyses, late MMN amplitude was significantly greater in children with typical PA ability than low PA ability. In contrast, laterality of the early and late MMN was significantly different in children with low versus typical RAN ability. Continuous analyses controlling for child age, non-verbal IQ, and letter and word identification abilities showed the same associations between late MMN amplitude with PA and late MMN laterality with RAN. These findings suggest that amplitude of the MMN may relate to phonological representations and ability to manipulate them, whereas MMN laterality may reflect differences in brain processes that support automaticity needed for reading.

Unveiling the Mysteries of Dyslexia-Lessons Learned from the Prospective Jyväskylä Longitudinal Study of Dyslexia

This paper reviews the observations of the Jyväskylä Longitudinal Study of Dyslexia (JLD). The JLD is a prospective family risk study in which the development of children with familial risk for dyslexia (N = 108) due to parental dyslexia and controls without dyslexia risk (N = 92) were followed from birth to adulthood. The JLD revealed that the likelihood of at-risk children performing poorly in reading and spelling tasks was fourfold compared to the controls. Auditory insensitivity of newborns observed during the first week of life using brain event-related potentials (ERPs) was shown to be the first precursor of dyslexia. ERPs measured at six months of age related to phoneme length identification differentiated the family risk group from the control group and predicted reading speed until the age of 14 years. Early oral language skills, phonological processing skills, rapid automatized naming, and letter knowledge differentiated the groups from ages 2.5-3.5 years onwards and predicted dyslexia and reading development, including reading comprehension, until adolescence. The home environment, a child's interest in reading, and task avoidance were not different in the risk group but were found to be additional predictors of reading development. Based on the JLD findings, preventive and intervention methods utilizing the association learning approach have been developed.

Speech discrimination in infants at family risk of dyslexia: Group and individual-based analyses

Deficiencies in discriminating and identifying speech sounds have been widely attested in individuals with dyslexia as well as in young children at family risk (FR) of dyslexia. A speech perception deficit has been hypothesized to be causally related to reading and spelling difficulties. So far, however, early speech perception of FR infants has not been assessed at different ages within a single experimental design. Furthermore, a combination of group- and individual-based analyses has not been made. In this cross-sectional study, vowel discrimination of 6-, 8-, and 10-month-old Dutch FR infants and their nonrisk (no-FR) peers was assessed. Infants (N = 196) were tested on a native English /aː/-/eː/ and non-native English /ɛ/-/æ/ contrast using a hybrid visual habituation paradigm. Frequentist analyses were used to interpret group differences. Bayesian hierarchical modeling was used to classify individuals as speech sound discriminators. FR and no-FR infants discriminated the native contrast at all ages. However, individual classification of the no-FR infants suggests improved discrimination with age, but not for the FR infants. No-FR infants discriminated the non-native contrast at 6 and 10 months, but not at 8 months. FR infants did not show evidence of discriminating the contrast at any of the ages, with 0% being classified as discriminators. The group- and individual-based data are complementary and together point toward speech perception differences between the groups. The findings also indicate that conducting individual analyses on hybrid visual habituation outcomes is possible. These outcomes form a fruitful avenue for gaining more understanding of development, group differences, and prospective relationships.

Perceptual expertise with Chinese characters predicts Chinese reading performance among Hong Kong Chinese children with developmental dyslexia

This study explores the theoretical proposal that developmental dyslexia involves a failure to develop perceptual expertise with words despite adequate education. Among a group of Hong Kong Chinese children diagnosed with developmental dyslexia, we investigated the relationship between Chinese word reading and perceptual expertise with Chinese characters. In a perceptual fluency task, the time of visual exposure to Chinese characters was manipulated and limited such that the speed of discrimination of a short sequence of Chinese characters at an accuracy level of 80% was estimated. Pair-wise correlations showed that perceptual fluency for characters predicted speeded and non-speeded word reading performance. Exploratory hierarchical regressions showed that perceptual fluency for characters accounted for 5.3% and 9.6% variance in speeded and non-speeded reading respectively, in addition to age, non-verbal IQ, phonological awareness, morphological awareness, rapid automatized naming (RAN) and perceptual fluency for digits. The findings suggest that perceptual expertise with words plays an important role in Chinese reading performance in developmental dyslexia, and that perceptual training is a potential remediation direction.

Development of Print-Speech Integration in the Brain of Beginning Readers With Varying Reading Skills

Learning print-speech sound correspondences is a crucial step at the beginning of reading acquisition and often impaired in children with developmental dyslexia. Despite increasing insight into audiovisual language processing, it remains largely unclear how integration of print and speech develops at the neural level during initial learning in the first years of schooling. To investigate this development, 32 healthy, German-speaking children at varying risk for developmental dyslexia (17 typical readers and 15 poor readers) participated in a longitudinal study including behavioral and fMRI measurements in first (T1) and second (T2) grade. We used an implicit audiovisual (AV) non-word target detection task aimed at characterizing differential activation to congruent (AVc) and incongruent (AVi) audiovisual non-word pairs. While children’s brain activation did not differ between AVc and AVi pairs in first grade, an incongruency effect (AVi > AVc) emerged in bilateral inferior temporal and superior frontal gyri in second grade. Of note, pseudoword reading performance improvements with time were associated with the development of the congruency effect (AVc > AVi) in the left posterior superior temporal gyrus (STG) from first to second grade. Finally, functional connectivity analyses indicated divergent development and reading expertise dependent coupling from the left occipito-temporal and superior temporal cortex to regions of the default mode (precuneus) and fronto-temporal language networks. Our results suggest that audiovisual integration areas as well as their functional coupling to other language areas and areas of the default mode network show a different development in poor vs. typical readers at varying familial risk for dyslexia.

Early Interactive Acoustic Experience with Non-speech Generalizes to Speech and Confers a Syllabic Processing Advantage at 9 Months

During early development, the infant brain is highly plastic and sensory experiences modulate emerging cortical maps, enhancing processing efficiency as infants set up key linguistic precursors. Early interactive acoustic experience (IAE) with spectrotemporally-modulated non-speech has been shown to facilitate optimal acoustic processing and generalizes to novel non-speech sounds at 7-months-of-age. Here we demonstrate that effects of non-speech IAE endure well beyond the immediate training period and robustly generalize to speech processing. Infants who received non-speech IAE differed at 9-months-of-age from both naïve controls and those with only passive acoustic exposure, demonstrating broad modulation of oscillatory dynamics. For the standard syllable, increased high-gamma (>70 Hz) power within auditory cortices indicates that IAE fosters native speech processing, facilitating establishment of phonemic representations. The higher left beta power seen may reflect increased linking of sensory information and corresponding articulatory patterns, while bilateral decreases in theta power suggest more mature automatized speech processing, as less neuronal resources were allocated to process syllabic information. For the deviant syllable, left-lateralized gamma (<70 Hz) enhancement suggests IAE promotes phonemic-related discrimination abilities. Theta power increases in right auditory cortex, known for favoring slow-rate decoding, implies IAE facilitates the more demanding processing of the sporadic deviant syllable.

Is atypical rhythm a risk factor for developmental speech and language disorders?

Although a growing literature points to substantial variation in speech/language abilities related to individual differences in musical abilities, mainstream models of communication sciences and disorders have not yet incorporated these individual differences into childhood speech/language development. This article reviews three sources of evidence in a comprehensive body of research aligning with three main themes: (a) associations between musical rhythm and speech/language processing, (b) musical rhythm in children with developmental speech/language disorders and common comorbid attentional and motor disorders, and (c) individual differences in mechanisms underlying rhythm processing in infants and their relationship with later speech/language development. In light of converging evidence on associations between musical rhythm and speech/language processing, we propose the Atypical Rhythm Risk Hypothesis, which posits that individuals with atypical rhythm are at higher risk for developmental speech/language disorders. The hypothesis is framed within the larger epidemiological literature in which recent methodological advances allow for large-scale testing of shared underlying biology across clinically distinct disorders. A series of predictions for future work testing the Atypical Rhythm Risk Hypothesis are outlined. We suggest that if a significant body of evidence is found to support this hypothesis, we can envision new risk factor models that incorporate atypical rhythm to predict the risk of developing speech/language disorders. Given the high prevalence of speech/language disorders in the population and the negative long-term social and economic consequences of gaps in identifying children at-risk, these new lines of research could potentially positively impact access to early identification and treatment. This article is categorized under: Linguistics > Language in Mind and Brain Neuroscience > Development Linguistics > Language Acquisition.

Novel word learning deficits in infants at family risk for dyslexia

Children of reading age diagnosed with dyslexia show deficits in reading and spelling skills, but early markers of later dyslexia are already present in infancy in auditory processing and phonological domains. Deficits in lexical development are not typically associated with dyslexia. Nevertheless, it is possible that early auditory/phonological deficits would have detrimental effects on the encoding and storage of novel lexical items. Word-learning difficulties have been demonstrated in school-aged dyslexic children using paired associate learning tasks, but earlier manifestations in infants who are at family risk for dyslexia have not been investigated. This study assessed novel word learning in 19-month-old infants at risk for dyslexia (by virtue of having one dyslexic parent) and infants not at risk for any developmental disorder. Infants completed a word-learning task that required them to map two novel words to their corresponding novel referents. Not at-risk infants showed increased looking time to the novel referents at test compared with at-risk infants. These findings demonstrate, for the first time, that at-risk infants show differences in novel word-learning (fast-mapping) tasks compared with not at-risk infants. Our findings have implications for the development and consolidation of early lexical and phonological skills in infants at family risk of later dyslexia.

Family-Centered Care Enhanced Neonatal Neurophysiological Function in Preterm Infants: Randomized Controlled Trial

BACKGROUND

Family-centered intervention for preterm infants has shown short- to medium-term developmental benefits; however, the neurological effects of intervention have rarely been explored.

OBJECTIVE

The objectives of this study were to examine the effect of a family-centered intervention program (FCIP) on neurophysiological functions in preterm infants with very low birth weight (VLBW; birth weight of < 1500 g) in Taiwan, to compare the effect of the FCIP with that of a usual-care program (UCP), and to explore the FCIP-induced changes in neurobehavioral and neurophysiological functions.

DESIGN

This was a multicenter, single-blind randomized controlled trial.

SETTING

The study took place in 3 medical centers in northern and southern Taiwan.

PARTICIPANTS

Two hundred fifty-one preterm infants with VLBW were included.

INTERVENTION

The FCIP group received a family-centered intervention and the UCP group received standard care during hospitalization.

MEASUREMENTS

Infants were assessed in terms of neurobehavioral performance using the Neonatal Neurobehavioral Examination-Chinese version, and their neurophysiological function was assessed using electroencephalography/event-related potentials during sleep and during an auditory oddball task during the neonatal period.

RESULTS

The FCIP promoted more mature neurophysiological function than the UCP, including greater negative mean amplitudes of mismatch negativities in the left frontal region in the oddball task in all infants, lower intrahemispheric prefrontal-central coherence during sleep in infants who were small for gestational age, and higher interhemispheric frontal coherence during sleep in those who were appropriate for gestational age. Furthermore, interhemispheric coherence was positively associated with the total neurobehavioral score in preterm infants who were appropriate for gestational age (r = 0.20).

LIMITATIONS

The fact that more parental adherence strategies were used in the FCIP group than in the UCP group might have favored the intervention effect in this study.

CONCLUSIONS

Family-centered intervention facilitates short-term neurophysiological maturation in preterm infants with VLBW in Taiwan.

Prenatal exposure to antiepileptic drugs and early processing of emotionally relevant sounds

INTRODUCTION

Prenatal exposure to antiepileptic drugs (AEDs) is associated with developmental compromises in verbal intelligence and social skills in childhood. Our aim was to evaluate whether a multifeature Mismatch Negativity (MMN) paradigm assessing semantic and emotional components of linguistic and emotional processing would be useful to detect possible alterations in early auditory processing of newborns with prenatal AED exposure.

MATERIAL AND METHODS

Data on AED exposure, pregnancy outcome, neuropsychological evaluation of the mothers, information on maternal epilepsy type, and a structured neurological examination of the newborn were collected prospectively. Blinded to AED exposure, we compared a cohort of 36 AED-exposed with 46 control newborns at the age of two weeks by measuring MMN with a multifeature paradigm with six linguistically relevant deviant sounds and three emotionally uttered sounds.

RESULTS

Frontal responses for the emotionally uttered stimulus Happy differed significantly in the exposed newborns compared with the control newborns. In addition, responses to sounds with or without emotional component differed in newborns exposed to multiple AEDs compared with control newborns or to newborns exposed to only one AED.

CONCLUSIONS

These preliminary findings suggest that prenatal AED exposure may alter early processing of emotionally and linguistically relevant sound information.

Individual differences in subphonemic sensitivity and phonological skills

Many studies have established a link between phonological abilities (indexed by phonological awareness and phonological memory tasks) and typical and atypical reading development. Individuals who perform poorly on phonological assessments have been mostly assumed to have underspecified (or "fuzzy") phonological representations, with typical phonemic categories, but with greater category overlap due to imprecise encoding. An alternative posits that poor readers have overspecified phonological representations, with speech sounds perceived allophonically (phonetically distinct variants of a single phonemic category). On both accounts, mismatch between phonological categories and orthography leads to reading difficulty. Here, we consider the implications of these accounts for online speech processing. We used eye tracking and an individual differences approach to assess sensitivity to subphonemic detail in a community sample of young adults with a wide range of reading-related skills. Subphonemic sensitivity inversely correlated with meta-phonological task performance, consistent with overspecification.

Delayed development of phonological constancy in toddlers at family risk for dyslexia

Phonological constancy refers to infants' ability to disregard variations in the phonetic realisation of speech sounds that do not indicate lexical contrast, e.g., when listening to accented speech. In typically-developing infants, this ability develops between 15- and 19-months of age, coinciding with the consolidation of infants' native phonological competence and vocabulary growth. Here we investigated the developmental time course of phonological constancy in infants at family risk for developmental dyslexia, using a longitudinal design. Developmental dyslexia is a disorder affecting the acquisition of reading and spelling skills, and it also affects early auditory processing, speech perception, and lexical acquisition. Infants at-risk and not at-risk for dyslexia, based on a family history of dyslexia, participated when they were 15-, 19-, and 26-months of age. Phonological constancy was indexed by comparing at-risk and not at-risk infants' ability to recognise familiar words in two preferential looking tasks: (1) a task using words presented in their native accent, and (2) a task using words presented in a non-native accent. We expected a delay in phonological constancy for the at-risk infants. As predicted, in the non-native accent task, not at-risk infants recognised familiar words by 19 months, but at-risk infants did not. The control infants thus exhibited phonological constancy. By 26 months, at-risk toddlers did show successful word recognition in the native accent task. However, for the non-native accent task at 26 months, neither at-risk nor control infants showed familiar word recognition. These findings are discussed in terms of the impact of family risk for dyslexia on toddlers' consolidation of early phonological and lexical skills.

Development of Dyslexia: The Delayed Neural Commitment Framework

It is now evident that explanations of many developmental disorders need to include a network perspective. In earlier work, we proposed that developmental dyslexia (DD) is well-characterized in terms of impaired procedural learning within the language networks, with the cerebellum being the key structure involved. Here, we deepen the analysis to include the child's developmental process of constructing these networks. The "Delayed Neural Commitment (DNC)" framework proposes that, in addition to slower skill acquisition, dyslexic children take longer to build (and to rebuild) the neural networks that underpin the acquisition of reading. The framework provides an important link backwards in time to the development of executive function networks and the earlier development of networks for language and speech. It is consistent with many theories of dyslexia while providing fruitful suggestions for further research at the genetic, brain, cognitive and behavioral levels of explanation. It also has significant implications for assessment and teaching.

Sensitivity to amplitude envelope rise time in infancy and vocabulary development at 3 years: A significant relationship

Here we report, for the first time, a relationship between sensitivity to amplitude envelope rise time in infants and their later vocabulary development. Recent research in auditory neuroscience has revealed that amplitude envelope rise time plays a mechanistic role in speech encoding. Accordingly, individual differences in infant discrimination of amplitude envelope rise times could be expected to relate to individual differences in language acquisition. A group of 50 infants taking part in a longitudinal study contributed rise time discrimination thresholds when aged 7 and 10 months, and their vocabulary development was measured at 3 years. Experimental measures of phonological sensitivity were also administered at 3 years. Linear mixed effect models taking rise time sensitivity as the dependent variable, and controlling for non-verbal IQ, showed significant predictive effects for vocabulary at 3 years, but not for the phonological sensitivity measures. The significant longitudinal relationship between amplitude envelope rise time discrimination and vocabulary development suggests that early rise time discrimination abilities have an impact on speech processing by infants.

Neural Underpinnings of Early Speech Perception and Emergent Literacy

Mismatch negativity (MMN) is an event-related potential component used to index automatic auditory change detection. Thus, MMN provides an excellent tool to assess the speech sensitivity of infants and children. Although MMN is well established in adults, the polarity and latency of mismatch responses (MMRs) in infants are highly inconsistent across studies. This paper aims to provide a comprehensive review of MMN studies of speech perception in early infancy. In particular, data from a series of MMN studies of Mandarin lexical tone, vowels, and initial consonants will be presented to demonstrate how phonological saliency, size of deviance, and neural maturation modulate MMRs in early infancy. These data suggest that MMN and positive MMRs index different functional characteristics and may provide information on when and how children's speech perception becomes automatic at different developmental stages. By using MMN to index sensitivity to speech discrimination, dyslexic children usually show reduced or absent MMN, which supports the relationship between phonological sensitivity and literacy. However, children with attention deficit/hyperactivity disorder showed the typical MMN, but attenuated P3a and enhanced late discriminative negativity. Taken together, the MMR characteristics, including amplitude, peak latency, and the transition of polarity, may be used to index the maturation of speech development and for the early identification of children with atypical language development.

Reduced left-lateralized pattern of event-related EEG oscillations in infants at familial risk for language and learning impairment

The ability to rapidly discriminate successive auditory stimuli within tens-of-milliseconds is crucial for speech and language development, particularly in the first year of life. This skill, called Rapid Auditory Processing (RAP), is altered in infants at familial risk for language and learning impairment (LLI) and is a robust predictor of later language outcomes. In the present study, we investigate the neural substrates of RAP, i.e., the underlying neural oscillatory patterns, in a group of Italian 6-month-old infants at risk for LLI (FH+, n = 24), compared to control infants with no known family history of LLI (FH−, n = 32). Brain responses to rapid changes in fundamental frequency and duration were recorded via high-density electroencephalogram during a non-speech double oddball paradigm. Sources of event-related potential generators were localized to right and left auditory regions in both FH+ and FH− groups. Time-frequency analyses showed variations in both theta (Ɵ) and gamma (ɣ) ranges across groups. Our results showed that overall RAP stimuli elicited a more left-lateralized pattern of oscillations in FH− infants, whereas FH+ infants demonstrated a more right-lateralized pattern, in both the theta and gamma frequency bands. Interestingly, FH+ infants showed reduced early left gamma power (starting at 50 ms after stimulus onset) during deviant discrimination. Perturbed oscillatory dynamics may well constitute a candidate neural mechanism to explain group differences in RAP. Additional group differences in source location suggest that anatomical variations may underlie differences in oscillatory activity. Regarding the predictive value of early oscillatory measures, we found that the amplitude of the source response and the magnitude of oscillatory power and phase synchrony were predictive of expressive vocabulary at 20 months of age. These results further our understanding of the interplay among neural mechanisms that support typical and atypical rapid auditory processing in infancy.

•

Neural sources of RAP in infancy were identified at right/left auditory regions.

•

FH− infants demonstrated a mature left-lateralized pattern of neural oscillations.

•

FH+ infants demonstrated a more right-lateralized pattern of neural oscillations.

•

FH+ infants showed reduced left gamma power during rapid auditory discrimination.

•

Source and oscillatory measures are both associated with later language skills.

Speech-in-noise perception ability can be related to auditory efferent pathway function: a comparative study in reading impaired and normal reading children

Introduction

Deficient auditory processing can cause problems with speech perception and affect the development and evolution of reading skills. The efferent auditory pathway has an important role in normal auditory system functions like speech-in-noise perception, but there is still no general agreement on this.

Objective

To study the performance of the efferent auditory system in a group of children with reading impairment in comparison with normal reading and evaluation of its relationship with speech-in-noise perception.

Methods

A total of 53 children between the ages of 8–12 years were selected for the study of which 27 were with reading impairment and 26 were normal reading children. Transient evoked otoacoustic emissions suppression and auditory recognition of words-in-noise test were performed for all the children.

Results

The average amplitude of transient evoked otoacoustic emissions suppression showed a significant difference between the two groups in the right (p = 0.004) and in the left ear (p = 0.028). Assessment of the relationship between transient evoked otoacoustic emissions suppression and monaural auditory recognition of words-in-noise scores showed a significant moderate negative relationship only in the right ear (p = 0.034, r = −0.41) of the normal reading children. Binaural auditory recognition of words-in-noise scores were significantly correlated with the amplitude of transient evoked otoacoustic emissions suppression in the right ear (p < 0.001, r = −0.75) and in the left ear (p < 0.001, r = −0.64) of normal reading children. In the reading impaired group, ?a weaker correlation was observed between binaural auditory recognition of words-in-noise scores and transient evoked otoacoustic emissions suppression in the right (p = 0.003, r = −0.55) and in the left ear (p = 0.012, r = −0.47).

Conclusions

Transient evoked otoacoustic emissions suppression pattern in the reading impaired group was different compared with normal reading children, and this difference could be related to efferent system performance. Words-in-noise scores in children with impaired reading were lower than in normal reading children. In addition, a relationship was found between transient evoked otoacoustic emissions suppression and words-in-noise scores in both normal and impaired reading children.

A preliminary study of auditory mismatch response on the day of cochlear implant activation in children with hearing aids prior implantation

Objective

The study aimed to explore the characteristics of auditory mismatch response (MMR) in hearing-impaired children on the day when the cochlear implant (CI) was started (power-up) and the speech processor was programmed, and to investigate the effects of wearing hearing aids (HAs) before cochlear implantation on the early stage of postoperative auditory cortex plasticity, providing some demonstrative data for the objective evaluation of postoperative early auditory ability in children who underwent cochlear implantation.

Methods

The participants were 34 children with profound sensorineural hearing loss, who underwent cochlear implantation. The classical passive Oddball paradigm was adopted, using a pair of vowels which only have different lexical tones. The standard stimulus was /a2/ and the devious stimulus was /a4/.

Results

1) On the day of CI activation, the auditory MMR has been elicited in 30 children; the MMR incidence was 88%. 2) We observed both positive and negative auditory MMR waveforms. And logistic regression analysis showed that it was influenced by the age at cochlear implantation. 3) The duration with HA before surgery significantly influenced the MMR latency. The children with longer duration of HA use have much earlier latency of MMR. 4) There was a significant positive correlation between the age at HA use initiation and MMR amplitude. Earlier initial HA use was associated with smaller amplitude.

Conclusions

MMR in response to Mandarin lexical tone can be recorded in most pediatric patients who had experience with HA on the day of CI power up. MMR is closely associated with the age at cochlear implantation, duration of HA use, and the age at HA use initiation. Hearing-impaired children should wear HA as early as possible and ensure consistent usage.

The somatosensory mismatch negativity as a window into body representations in infancy

How the body is represented in the developing brain is a topic of growing interest. The current study takes a novel approach to investigating neural body representations in infants by recording somatosensory mismatch negativity (sMMN) responses elicited by tactile stimulation of different body locations. Recent research in adults has suggested that sMMN amplitude may be influenced by the relative distance between representations of the stimulated body parts in somatosensory cortex. The current study uses a similar paradigm to explore whether the sMMN can be elicited in infants, and to test whether the infant sMMN response is sensitive to the somatotopic organization of somatosensory cortex. Participants were healthy infants (n = 31) aged 6 and 7 months. The protocol leveraged a discontinuity in cortical somatotopic organization, whereby the representations of the neck and the face are separated by representations of the arms, the hands and the shoulder. In a double-deviant oddball protocol, stimulation of the hand (100 trials, 10% probability) and neck (100 trials, 10% probability) was interspersed among repeated stimulation of the face (800 trials, 80% probability). Waveforms showed evidence of an infant sMMN response that was significantly larger for the face/neck contrast than for the face/hand contrast. These results suggest that, for certain combinations of body parts, early pre-attentive tactile discrimination in infants may be influenced by distance between the corresponding cortical representations. The results provide the first evidence that the sMMN can be elicited in infants, and pave the way for further applications of the sMMN in studying body representations in preverbal infants.

Developmental changes in automatic rule-learning mechanisms across early childhood

Infants' ability to learn complex linguistic regularities from early on has been revealed by electrophysiological studies indicating that 3-month-olds, but not adults, can automatically detect non-adjacent dependencies between syllables. While different ERP responses in adults and infants suggest that both linguistic rule learning and its link to basic auditory processing undergo developmental changes, systematic investigations of the developmental trajectories are scarce. In the present study, we assessed 2- and 4-year-olds' ERP indicators of pitch discrimination and linguistic rule learning in a syllable-based oddball design. To test for the relation between auditory discrimination and rule learning, ERP responses to pitch changes were used as predictor for potential linguistic rule-learning effects. Results revealed that 2-year-olds, but not 4-year-olds, showed ERP markers of rule learning. Although, 2-year-olds' rule learning was not dependent on differences in pitch perception, 4-year-old children demonstrated a dependency, such that those children who showed more pronounced responses to pitch changes still showed an effect of rule learning. These results narrow down the developmental decline of the ability for automatic linguistic rule learning to the age between 2 and 4 years, and, moreover, point towards a strong modification of this change by auditory processes. At an age when the ability of automatic linguistic rule learning phases out, rule learning can still be observed in children with enhanced auditory responses. The observed interrelations are plausible causes for age-of-acquisition effects and inter-individual differences in language learning.

Comparing the Effect of Thinking Maps Training Package Developed by the Thinking Maps Method on the Reading Performance of Dyslexic Students

The present study aimed to develop the thinking maps training package and compare its training effect with the thinking maps method on the reading performance of second and fifth grade of elementary school male dyslexic students. For this mixed method exploratory study, from among the above mentioned grades' students in Isfahan, 90 students who met the inclusion criteria were selected by multistage sampling and randomly assigned into six experimental and control groups. The data were collected by reading and dyslexia test and Wechsler Intelligence Scale for Children-fourth edition. The results of covariance analysis indicated a significant difference between the reading performance of the experimental (thinking maps training package and thinking maps method groups) and control groups ([Formula: see text]). Moreover, there were significant differences between the thinking maps training package group and thinking maps method group in some of the subtests ([Formula: see text]). It can be concluded that thinking maps training package and the thinking maps method exert a positive influence on the reading performance of dyslexic students; therefore, thinking maps can be used as an effective training and treatment method.

Simulating reading acquisition: The link between reading outcome and multimodal brain signatures of letter-speech sound learning in prereaders

During reading acquisition, neural reorganization of the human brain facilitates the integration of letters and speech sounds, which enables successful reading. Neuroimaging and behavioural studies have established that impaired audiovisual integration of letters and speech sounds is a core deficit in individuals with developmental dyslexia. This longitudinal study aimed to identify neural and behavioural markers of audiovisual integration that are related to future reading fluency. We simulated the first step of reading acquisition by performing artificial-letter training with prereading children at risk for dyslexia. Multiple logistic regressions revealed that our training provides new precursors of reading fluency at the beginning of reading acquisition. In addition, an event-related potential around 400 ms and functional magnetic resonance imaging activation patterns in the left planum temporale to audiovisual correspondences improved cross-validated prediction of future poor readers. Finally, an exploratory analysis combining simultaneously acquired electroencephalography and hemodynamic data suggested that modulation of temporoparietal brain regions depended on future reading skills. The multimodal approach demonstrates neural adaptations to audiovisual integration in the developing brain that are related to reading outcome. Despite potential limitations arising from the restricted sample size, our results may have promising implications both for identifying poor-reading children and for monitoring early interventions.

Cortical Responses to Chinese Phonemes in Preschoolers Predict Their Literacy Skills at School Age

We investigated whether preschoolers with poor phonological awareness (PA) skills had impaired cortical basis for detecting speech feature, and whether speech perception influences future literacy outcomes in preschoolers. We recorded ERP responses to speech in 52 Chinese preschoolers. The results showed that the poor PA group processed speech changes differentially compared to control group in mismatch negativity (MMN) and late discriminative negativity (LDN). Furthermore, speech perception in kindergarten could predict literacy outcomes after literacy acquisition. These suggest that impairment in detecting speech features occurs before formal reading instruction, and that speech perception plays an important role in reading development.

Investigating the Influences of Language Delay and/or Familial Risk for Dyslexia on Brain Structure in 5-Year-Olds

Early language delay has often been associated with atypical language/literacy development. Neuroimaging studies further indicate functional disruptions during language and print processing in school-age children with a retrospective report of early language delay. Behavioral data of 114 5-year-olds with a retrospective report of early language delay in infancy (N = 34) and those without (N = 80) and with a familial risk for dyslexia and those without are presented. Behaviorally, children with a retrospective report of early language delay exhibited reduced performance in language/reading-related measures. A voxel-based morphometry analysis in a subset (N = 46) demonstrated an association between reduced gray matter volume and early language delay in left-hemispheric middle temporal, occipital, and frontal regions. Alterations in middle temporal cortex in children with a retrospective report of early language delay were observed regardless of familial risk for dyslexia. Additionally, while children with isolated familial risk for dyslexia showed gray matter reductions in temporoparietal and occipitotemporal regions, these effects were most profound in children with both risk factors. An interaction effect of early language delay and familial risk was revealed in temporoparietal, occipital, and frontal cortex. Our findings support a cumulative effect of early behavioral and genetic risk factors on brain development and may ultimately inform diagnosis/treatment.

Distinct ERP profiles for auditory processing in infants at-risk for autism and language impairment

Early identification of autism spectrum disorder (ASD) is crucial for the formulation of effective intervention programs. Language deficits may be a hallmark feature of ASD and language delay observed in ASD shows striking similarities to that observed in children with language impairment (LI). Auditory processing deficits are seen in both LI and ASD, however, they have not previously been compared directly using Event-Related Potentials (ERPs) in the two at-risk populations. This study aims to characterize infants at-risk for ASD (HR-ASD) at the electrophysiological level and to compare them with infants at-risk for LI (HR-LI) and controls, to find specific markers with predictive value. At 12-month-old, auditory processing in HR-ASD, HR-LI and controls was characterized via ERP oddball paradigm. All infants were then evaluated at 20 months, to investigate the associations between auditory processing and language/ASD-related outcomes. In both HR-ASD and HR-LI, mismatch response latency was delayed compared to controls, whereas only HR-ASD showed overall larger P3 amplitude compared to controls. Interestingly, these ERP measures correlated with later expressive vocabulary and M-CHAT critical items in the whole sample. These results may support the use of objective measurement of auditory processing to delineate pathophysiological mechanisms in ASD, as compared to LI.