Dynamics of cognitive predictors during reading acquisition in a sample of children overrepresented for dyslexia risk.

Literacy acquisition is a complex process with genetic and environmental factors influencing cognitive and neural processes associated with reading. Previous research identified factors that predict word reading fluency (WRF), including phonological awareness (PA), rapid automatized naming (RAN), and speech-in-noise perception (SPIN). Recent theoretical accounts suggest dynamic interactions between these factors and reading, but direct investigations of such dynamics are lacking. Here, we investigated the dynamic effect of phonological processing and speech perception on WRF. More specifically, we evaluated the dynamic influence of PA, RAN, and SPIN measured in kindergarten (the year prior to formal reading instruction), first grade (the first year of formal reading instruction) and second grade on WRF in second and third grade. We also assessed the effect of an indirect proxy of family risk for reading difficulties using a parental questionnaire (Adult Reading History Questionnaire, ARHQ). We applied path modeling in a longitudinal sample of 162 Dutch-speaking children of whom the majority was selected to have an increased family and/or cognitive risk for dyslexia. We showed that parental ARHQ had a significant effect on WRF, RAN and SPIN, but unexpectedly not on PA. We also found effects of RAN and PA directly on WRF that were limited to first and second grade respectively, in contrast to previous research reporting pre-reading PA effects and prolonged RAN effects throughout reading acquisition. Our study provides important new insights into early prediction of later word reading abilities and into the optimal time window to target a specific reading-related subskill during intervention.

Pulsatile modulation greatly enhances neural synchronization at syllable rate in children.

Neural processing of the speech envelope is of crucial importance for speech perception and comprehension. This envelope processing is often investigated by measuring neural synchronization to sinusoidal amplitude-modulated stimuli at different modulation frequencies. However, it has been argued that these stimuli lack ecological validity. Pulsatile amplitude-modulated stimuli, on the other hand, are suggested to be more ecologically valid and efficient, and have increased potential to uncover the neural mechanisms behind some developmental disorders such a dyslexia. Nonetheless, pulsatile stimuli have not yet been investigated in pre-reading and beginning reading children, which is a crucial age for developmental reading research. We performed a longitudinal study to examine the potential of pulsatile stimuli in this age range. Fifty-two typically reading children were tested at three time points from the middle of their last year of kindergarten (5 years old) to the end of first grade (7 years old). Using electroencephalography, we measured neural synchronization to syllable rate and phoneme rate sinusoidal and pulsatile amplitude-modulated stimuli. Our results revealed that the pulsatile stimuli significantly enhance neural synchronization at syllable rate, compared to the sinusoidal stimuli. Additionally, the pulsatile stimuli at syllable rate elicited a different hemispheric specialization, more closely resembling natural speech envelope tracking. We postulate that using the pulsatile stimuli greatly increases EEG data acquisition efficiency compared to the common sinusoidal amplitude-modulated stimuli in research in younger children and in developmental reading research.

Neural synchronization and intervention in pre-readers who later on develop dyslexia.

A growing number of studies has investigated temporal processing deficits in dyslexia. These studies largely focus on neural synchronization to speech. However, the importance of rise times for neural synchronization is often overlooked. Furthermore, targeted interventions, phonics-based and auditory, are being developed, but little is known about their impact. The current study investigated the impact of a 12-week tablet-based intervention. Children at risk for dyslexia received phonics-based training, either with (n = 31) or without (n = 31) auditory training, or engaged in active control training (n = 29). Additionally, neural synchronization and processing of rise times was longitudinally investigated in children with dyslexia (n = 26) and typical readers (n = 52) from pre-reading (5 years) to beginning reading age (7 years). The three time points in the longitudinal study correspond to intervention pre-test, post-test and consolidation, approximately 1 year after completing the intervention. At each time point neural synchronization was measured to sinusoidal stimuli and pulsatile stimuli with shortened rise times at syllable (4 Hz) and phoneme rates (20 Hz). Our results revealed no impact on neural synchronization at syllable and phoneme rate of the phonics-based and auditory training. However, we did reveal atypical hemispheric specialization at both syllable and phoneme rates in children with dyslexia. This was detected even before the onset of reading acquisition, pointing towards a possible causal rather than consequential mechanism in dyslexia. This study contributes to our understanding of the temporal processing deficits underlying the development of dyslexia, but also shows that the development of targeted interventions is still a work in progress.

Comparing the Outcomes of a Personalized Versus Nonpersonalized Home-Based Auditory Training Program for Cochlear Implant Users.

OBJECTIVES: Audiological rehabilitation includes sensory management, auditory training (AT), and counseling and can alleviate the negative consequences associated with (untreated) hearing impairment. AT aims at improving auditory skills through structured analytical (bottom-up) or synthetic (top-down) listening exercises. The evidence for AT to improve auditory outcomes of postlingually deafened adults with a cochlear implant (CI) remains a point of debate due to the relatively limited number of studies and methodological shortcomings. There is a general agreement that more rigorous scientific study designs are needed to determine the effectiveness, generalization, and consolidation of AT for CI users. The present study aimed to investigate the effectiveness of a personalized AT program compared to a nonpersonalized Active Control program with adult CI users in a stratified randomized controlled clinical trial. DESIGN: Off-task outcomes were sentence understanding in noise, executive functioning, and health-related quality of life. Participants were tested before and after 16 weeks of training and after a further 8 months without training. Participant expectations of the training program were assessed before the start of training. RESULTS: The personalized and nonpersonalized AT programs yielded similar results. Significant on-task improvements were observed. Moreover, AT generalized to improved speech understanding in noise for both programs. Half of the CI users reached a clinically relevant improvement in speech understanding in noise of at least 2 dB SNR post-training. These improvements were maintained 8 months after completion of the training. In addition, a significant improvement in quality of life was observed for participants in both treatment groups. Adherence to the training programs was high, and both programs were considered user-friendly. CONCLUSIONS: Training in both treatments yielded similar results. For half of the CI users, AT transferred to better performance with generalization of learning for speech understanding in noise and quality of life. Our study supports the previous findings that AT can be beneficial for some CI users.

Investigating the impact of early literacy training on white matter structure in prereaders at risk for dyslexia.

Recent prereading evidence demonstrates that white matter alterations are associated with dyslexia even before the onset of reading instruction. At the same time, remediation of reading difficulties is suggested to be most effective when provided as early as kindergarten, yet evidence is currently lacking on the early neuroanatomical changes associated with such preventive interventions. To address this open question, we investigated white matter changes following early literacy intervention in Dutch-speaking prereaders (aged 5-6 years) with an increased cognitive risk for developing dyslexia. Diffusion-weighted images were acquired before and after a 12-week digital intervention in three groups: (i) at-risk children receiving phonics-based training (n = 31); (ii) at-risk children engaging with active control training (n = 25); and (iii) typically developing children (n = 27) receiving no intervention. Following automated quantification of white matter tracts relevant for reading, we first examined baseline differences between at-risk and typically developing children, revealing bilateral dorsal and ventral differences. Longitudinal analyses showed that white matter properties changed within the course of the training; however, the absence of intervention-specific results suggests that these changes rather reflect developmental effects. This study contributes important first insights on the neurocognitive mechanisms of intervention that precedes formal reading onset.

Lilliput: speech perception in speech-weighted noise and in quiet in young children.

OBJECTIVE: The aim of this study was to develop an open-set word recognition task in speech-weighted noise and in quiet for young children and examine age effects for open versus closed response formats. DESIGN: Dutch monosyllabic words were presented in quiet and in stationary speech-weighted noise to 4- and 5-year-old children as well as to young adults in an open-set response format. Additionally, performance in open and closed context was assessed, as well as in a picture-pointing paradigm. STUDY SAMPLE: More than 200 children and 50 adults with normal hearing participated in the various validation phases. RESULTS: Average fitted speech reception thresholds (50%) yielded an age effect between 4-year and 5-year olds (and adults), both in speech-weighted noise and in quiet. The closed-set format yielded lower (better) SNRs than the open-set format, and children benefitted to the same extent as adults from phonetically similar words in speech-weighted noise. Additionally, the 4 AFC picture-pointing paradigm can be used to assess word recognition in quiet from 3 years of age. CONCLUSIONS: The same materials reveal performance differences between 4 and 5 years of age (and adults), both in quiet and speech-weighted noise using an open-set response format. This relatively small yet significant difference in SRT for a gap of only 1 year shows a developmental change for word recognition in speech-weighted noise and in quiet in the first decade of life.The study is part of the protocol registered on ClinicalTrials.gov (ID = NCT04063748).

Electrophysiologic Evidence That Directional Deep Brain Stimulation Activates Distinct Neural Circuits in Patients With Parkinson Disease.

OBJECTIVES: Deep brain stimulation (DBS) delivered via multicontact leads implanted in the basal ganglia is an established therapy to treat Parkinson disease (PD). However, the different neural circuits that can be modulated through stimulation on different DBS contacts are poorly understood. Evidence shows that electrically stimulating the subthalamic nucleus (STN) causes a therapeutic effect through antidromic activation of the hyperdirect pathway-a monosynaptic connection from the cortex to the STN. Recent studies suggest that stimulating the substantia nigra pars reticulata (SNr) may improve gait. The advent of directional DBS leads now provides a spatially precise means to probe these neural circuits and better understand how DBS affects distinct neural networks. MATERIALS AND METHODS: We measured cortical evoked potentials (EPs) using electroencephalography (EEG) in response to low-frequency DBS using the different directional DBS contacts in eight patients with PD. RESULTS: A short-latency EP at 3 milliseconds originating from the primary motor cortex appeared largest in amplitude when stimulating DBS contacts closest to the dorsolateral STN (p < 0.001). A long-latency EP at 10 milliseconds originating from the premotor cortex appeared strongest for DBS contacts closest to the SNr (p < 0.0001). CONCLUSIONS: Our results show that at the individual patient level, electrical stimulation of different nuclei produces distinct EP signatures. Our approach could be used to identify the functional location of each DBS contact and thus help patient-specific DBS programming. CLINICAL TRIAL REGISTRATION: The ClinicalTrials.gov registration number for the study is NCT04658641.

Ahead of maturation: Enhanced speech envelope training boosts rise time discrimination in pre-readers at cognitive risk for dyslexia.

Dyslexia has frequently been related to atypical auditory temporal processing and speech perception. Results of studies emphasizing speech onset cues and reinforcing the temporal structure of the speech envelope, that is, envelope enhancement (EE), demonstrated reduced speech perception deficits in individuals with dyslexia. The use of this strategy as auditory intervention might thus reduce some of the deficits related to dyslexia. Importantly, reading-skill interventions are most effective when they are provided during kindergarten and first grade. Hence, we provided a tablet-based 12-week auditory and phonics-based intervention to pre-readers at cognitive risk for dyslexia and investigated the effect on auditory temporal processing with a rise time discrimination (RTD) task. Ninety-one pre-readers at cognitive risk for dyslexia (aged 5-6) were assigned to two groups receiving a phonics-based intervention and playing a story listening game either with (n = 31) or without (n = 31) EE or a third group playing control games and listening to non-enhanced stories (n = 29). RTD was measured directly before, directly after and 1 year after the intervention. While the groups listening to non-enhanced stories mainly improved after the intervention during first grade, the group listening to enhanced stories improved during the intervention in kindergarten and subsequently remained stable during first grade. Hence, an EE intervention improves auditory processing skills important for the development of phonological skills. This occurred before the onset of reading instruction, preceding the maturational improvement of these skills, hence potentially giving at risk children a head start when learning to read. A video abstract of this article can be viewed at https://www.youtube.com/watch?v=e0BfT4dGXNA.

The digit triplet test as a self-test for hearing screening at the age of school-entry.

OBJECTIVE: The current study aimed to investigate the feasibility of the digit triplet test (DTT) as a self-test in normal-hearing children at school-entry age (5-6 years) compared to an administrator-controlled test. DESIGN AND STUDY SAMPLE: Thirty-seven first grade elementary school children took part in this study. Next to a pure-tone screening, the test battery consisted of a DTT speech-in-noise screening (self-test and administrator-controlled assessment), and cognitive tests related to auditory/working memory and attention skills. RESULTS: The reference-SRT ± 2SD, obtained with the administrator-controlled DTT, was -9.8 ± 1.6 dB SNR, and could be estimated with a precision of 0.7 dB. The test duration for one ear was about 4.5 min. Self-tests resulted in higher (poorer) SRTs. Only a small proportion of children performed stably across repeated self-test administrations. With about 6 min for one ear, the test duration was rather long. The influence of auditory/working memory and attentional abilities appeared to be limited. CONCLUSION: Our data suggest that a self-administered DTT is not suitable for a large proportion of children at school-entry.

A three-time point longitudinal investigation of the arcuate fasciculus throughout reading acquisition in children developing dyslexia.

Although the neural basis of dyslexia has intensively been investigated, results are still unclear about the existence of a white matter deficit in the arcuate fasciculus (AF) throughout development. To unravel this ambiguity, we examined the difference in fractional anisotropy (FA) of the AF between children developing dyslexia and children developing typical reading skills in a longitudinal sample with three MRI time points throughout reading development: the pre-reading stage (5-6 years old), the early reading stage (7-8 years old) and the advanced reading stage (9-10 years old). Applying along-the-tract analyses of white matter organization, our results confirmed that a white matter deficit existed in the left AF prior to the onset of formal reading instruction in children who developed dyslexia later on. This deficit was consistently present throughout the course of reading development. Additionally, we evaluated the use of applying a continuous approach on the participants' reading skills rather than the arbitrary categorization in individuals with or without dyslexia. Our results confirmed the predictive relation between FA and word reading measurements later in development. This study supports the use of longitudinal approaches to investigate the neural basis of the developmental process of learning to read and the application of triangulation, i.e. using multiple research approaches to help gain more insight and aiding the interpretation of obtained results.

Cortical compensation for hearing loss, but not age, in neural tracking of the fundamental frequency of the voice.

Auditory processing is affected by advancing age and hearing loss, but the underlying mechanisms are still unclear. We investigated the effects of age and hearing loss on temporal processing of naturalistic stimuli in the auditory system. We used a recently developed objective measure for neural phase-locking to the fundamental frequency of the voice (f0) which uses continuous natural speech as a stimulus, that is, "f0-tracking." The f0-tracking responses from 54 normal-hearing and 14 hearing-impaired adults of varying ages were analyzed. The responses were evoked by a Flemish story with a male talker and contained contributions from both subcortical and cortical sources. Results indicated that advancing age was related to smaller responses with less cortical response contributions. This is consistent with an age-related decrease in neural phase-locking ability at frequencies in the range of the f0, possibly due to decreased inhibition in the auditory system. Conversely, hearing-impaired subjects displayed larger responses compared with age-matched normal-hearing controls. This was due to additional cortical response contributions in the 38- to 50-ms latency range, which were stronger for participants with more severe hearing loss. This is consistent with hearing-loss-induced cortical reorganization and recruitment of additional neural resources to aid in speech perception.NEW & NOTEWORTHY Previous studies disagree on the effects of age and hearing loss on the neurophysiological processing of the fundamental frequency of the voice (f0), in part due to confounding effects. Using a novel electrophysiological technique, natural speech stimuli, and controlled study design, we quantified and disentangled the effects of age and hearing loss on neural f0 processing. We uncovered evidence for underlying neurophysiological mechanisms, including a cortical compensation mechanism for hearing loss, but not for age.

The identification of predominant auditory steady-state response brain sources in electroencephalography using denoising source separation.

Different approaches have been used to extract auditory steady-state responses (ASSRs) from electroencephalography (EEG) recordings, including region-related electrode configurations (electrode level) and the manual placement of equivalent current dipoles (source level). Inherent limitations of these approaches are the assumption of the anatomical origin and the omission of activity generated by secondary sources. Data-driven methods such as independent component analysis (ICA) seem to avoid these limitations but only to face new others such as the presence of ASSRs with similar properties in different components and the manual selection protocol to select and classify the most relevant components carrying ASSRs. We propose the novel approach of applying a spatial filter to these components in order to extract the most relevant information. We aimed to develop a method based on the reproducibility across trials that performs reliably in low-signal-to-noise ratio (SNR) scenarios using denoising source separation (DSS). DSS combined with ICA successfully reduced the number of components and extracted the most relevant ASSR at 4, 10 and 20 Hz stimulation in group and individual level studies of EEG adolescent data. The anatomical brain location for these low stimulation frequencies showed results in cortical areas with relatively small dispersion. However, for 40 and 80 Hz, results with regard to the number of components and the anatomical origin were less clear. At all stimulation frequencies the outcome measures were consistent with literature, and the partial rejection of inter-subject variability led to more accurate results and higher SNRs. These findings are promising for future applications in group comparison involving pathologies.

Neural tracking of the fundamental frequency of the voice: The effect of voice characteristics.

Traditional electrophysiological methods to study temporal auditory processing of the fundamental frequency of the voice (f0) often use unnaturally repetitive stimuli. In this study, we investigated f0 processing of meaningful continuous speech. EEG responses evoked by stories in quiet were analysed with a novel method based on linear modelling that characterizes the neural tracking of the f0. We studied both the strength and the spatio-temporal properties of the f0-tracking response. Moreover, different samples of continuous speech (six stories by four speakers: two male and two female) were used to investigate the effect of voice characteristics on the f0 response. The results indicated that response strength is inversely related to f0 frequency and rate of f0 change throughout the story. As a result, the male-narrated stories in this study (low and steady f0) evoked stronger f0-tracking compared to female-narrated stories (high and variable f0), for which many responses were not significant. The spatio-temporal analysis revealed that f0-tracking response generators were not fixed in the brainstem but were voice-dependent as well. Voices with high and variable f0 evoked subcortically dominated responses with a latency between 7 and 12 ms. Voices with low and steady f0 evoked responses that are both subcortically (latency of 13-15 ms) and cortically (latency of 23-26 ms) generated, with the right primary auditory cortex as a likely cortical source. Finally, additional experiments revealed that response strength greatly improves for voices with strong higher harmonics, which is particularly useful to boost the small responses evoked by voices with high f0.

Atypical processing in neural source analysis of speech envelope modulations in adolescents with dyslexia.

Different studies have suggested that language and developmental disorders such as dyslexia are associated with a disturbance of auditory entrainment and of the functional hemispheric asymmetries during speech processing. These disorders typically result from an issue in the phonological component of language that causes problems to represent and manipulate the phonological structure of words at the syllable and/or phoneme level. We used Auditory Steady-State Responses (ASSRs) in EEG recordings to investigate the brain activation and hemisphere asymmetry of theta, alpha, beta and low-gamma range oscillations in typical readers and readers with dyslexia. The aim was to analyse whether the group differences found in previous electrode level studies were caused by a different source activation pattern or conversely was an effect that could be found on the active brain sources. We could not find differences in the brain locations of the main active brain sources. However, we observed differences in the extracted waveforms. The group average of the first DSS component of all signal-to-noise ratios of ASSR at source level was higher than the group averages at the electrode level. These analyses included a lower alpha synchronisation in adolescents with dyslexia and the possibility of compensatory mechanisms in theta, beta and low-gamma frequency bands. The main brain auditory sources were located in cortical regions around the auditory cortex. Thus, the differences observed in auditory EEG experiments would, according to our findings, have their origin in the intrinsic oscillatory mechanisms of the brain cortical sources related to speech perception.

Brain mapping of auditory steady-state responses: A broad view of cortical and subcortical sources.

Auditory steady-state responses (ASSRs) are evoked brain responses to modulated or repetitive acoustic stimuli. Investigating the underlying neural generators of ASSRs is important to gain in-depth insight into the mechanisms of auditory temporal processing. The aim of this study is to reconstruct an extensive range of neural generators, that is, cortical and subcortical, as well as primary and non-primary ones. This extensive overview of neural generators provides an appropriate basis for studying functional connectivity. To this end, a minimum-norm imaging (MNI) technique is employed. We also present a novel extension to MNI which facilitates source analysis by quantifying the ASSR for each dipole. Results demonstrate that the proposed MNI approach is successful in reconstructing sources located both within (primary) and outside (non-primary) of the auditory cortex (AC). Primary sources are detected in different stimulation conditions (four modulation frequencies and two sides of stimulation), thereby demonstrating the robustness of the approach. This study is one of the first investigations to identify non-primary sources. Moreover, we show that the MNI approach is also capable of reconstructing the subcortical activities of ASSRs. Finally, the results obtained using the MNI approach outperform the group-independent component analysis method on the same data, in terms of detection of sources in the AC, reconstructing the subcortical activities and reducing computational load.

Structural brain dynamics across reading development: A longitudinal MRI study from kindergarten to grade 5.

Primary education is the incubator for learning academic skills that help children to become a literate, communicative, and independent person. Over this learning period, nonlinear and regional changes in the brain occur, but how these changes relate to academic performance, such as reading ability, is still unclear. In the current study, we analyzed longitudinal T1 MRI data of 41 children in order to investigate typical cortical development during the early reading stage (end of kindergarten-end of grade 2) and advanced reading stage (end of grade 2-middle of grade 5), and to detect putative deviant trajectories in children with dyslexia. The structural brain change was quantified with a reliable measure that directly calculates the local morphological differences between brain images of two time points, while considering the global head growth. When applying this measure to investigate typical cortical development, we observed that left temporal and temporoparietal regions belonging to the reading network exhibited an increase during the early reading stage and stabilized during the advanced reading stage. This suggests that the natural plasticity window for reading is within the first years of primary school, hence earlier than the typical period for reading intervention. Concerning neurotrajectories in children with dyslexia compared to typical readers, we observed no differences in gray matter development of the left reading network, but we found different neurotrajectories in right IFG opercularis (during the early reading stage) and in right isthmus cingulate (during the advanced reading stage), which could reflect compensatory neural mechanisms.

The Cost of Intrinsic and Extrinsic Cognitive Demands on Auditory Functioning in Older Adults With Normal Hearing or Using Hearing Aids.

OBJECTIVES: We investigated the impact of both intrinsic and extrinsic cognitive demands on auditory and secondary task performance in older adults with normal hearing (NH) and adults using hearing aids (HAs) in an ecologically relevant listening environment. DESIGN: Fifteen adults with NH and 15 adults using HAs (60 to 72 years of age) were recruited to perform the "Audiovisual True-to-Life Assessment of Auditory Rehabilitation"-paradigm (AVATAR), which combines an auditory-visual speech-in-noise task with three secondary tasks on either auditory localization or visual short-term memory in a preload multitask paradigm. Intrinsic demands were altered by presenting speech either at equivalent speech accuracy levels of 50% correct (SPIN50%) or equivalent speech-to-noise ratios of +5dB SNR (SPIN+5dB). We manipulated the amount of extrinsic cognitive demands by including one (dual condition) or three secondary tasks (quadruple condition). Performance decrements on the secondary tasks were considered to reflect an increase in resource allocation to speech understanding and thus an increase in listening effort. In addition, we administered a cognitive test battery as well as a questionnaire on self-reported hearing difficulties and subjective measures of effort and motivation. RESULTS: Speech understanding and secondary task performance on the visual short-term memory task were lower in the SPIN50% condition compared to SPIN+5dB. Whereas speech understanding at SPIN50% was equally high in the dual and quadruple conditions, the quadruple condition resulted in lower secondary task performance on the visual short-term memory task, higher levels of self-reported effort, and lower motivation compared to the dual-task condition. The same was true for experimental conditions at SPIN+5dB. Additionally, adults with NH outperformed adults using HAs on speech understanding, auditory localization, and self-reported hearing abilities, but no group differences were observed on secondary task costs or cognitive measures. CONCLUSIONS: This study showed that, irrespective of the hearing status of the listener, speech performance was not affected by the amount of extrinsic cognitive demands, but was worse and required more effort under conditions with a more negative SNR. Also, increasing the extrinsic cognitive demands resulted in lower performance on one of the secondary tasks, suggesting that more complex listening environments require more effort. Although adults with NH outperformed HA users on speech understanding and auditory localization, the two groups did not differ with respect to secondary task costs.

The digit triplet test: a scoping review.

OBJECTIVE: This review article presents an overview of all Digit Triplet Tests (DTT) and digits-in-noise tests (DIN) and their variations in language, speech material, masking noise, test procedures, and targeted population. The effects on aspects of validity, reliability, and feasibility are investigated. DESIGN: Scoping review. STUDY SAMPLE: All studies referring to the DTT and DIN were collected from Pubmed and Embase. Search terms "digit triplet test" and "digits in noise" were used. Citations of selected articles were scanned backwards in time (the bibliography of the already selected research article) and forward in time (articles that cited the already selected research article). The search terms yielded 95 results in total. Eventually, 39 papers were selected. RESULTS: Analyses showed psychometric reference-curves with steep slopes and speech reception thresholds with high measurement precision which are strongly associated with pure tone audiometry. High sensitivity and specificity to detect elevated pure tone thresholds were noted for test variants. Certain procedural modifications of the DTT and DIN can further improve the test. Additionally, large-scale application of the DTT and DIN is feasible. CONCLUSION: The DTT and DIN are a very valuable tool for screening and diagnostics for a wide variety of populations.

Brain activity patterns of phonemic representations are atypical in beginning readers with family risk for dyslexia.

There is an ongoing debate whether phonological deficits in dyslexics should be attributed to (a) less specified representations of speech sounds, like suggested by studies in young children with a familial risk for dyslexia, or (b) to an impaired access to these phonemic representations, as suggested by studies in adults with dyslexia. These conflicting findings are rooted in between study differences in sample characteristics and/or testing techniques. The current study uses the same multivariate functional MRI (fMRI) approach as previously used in adults with dyslexia to investigate phonemic representations in 30 beginning readers with a familial risk and 24 beginning readers without a familial risk of dyslexia, of whom 20 were later retrospectively classified as dyslexic. Based on fMRI response patterns evoked by listening to different utterances of /bA/ and /dA/ sounds, multivoxel analyses indicate that the underlying activation patterns of the two phonemes were distinct in children with a low family risk but not in children with high family risk. However, no group differences were observed between children that were later classified as typical versus dyslexic readers, regardless of their family risk status, indicating that poor phonemic representations constitute a risk for dyslexia but are not sufficient to result in reading problems. We hypothesize that poor phonemic representations are trait (family risk) and not state (dyslexia) dependent, and that representational deficits only lead to reading difficulties when they are present in conjunction with other neuroanatomical or-functional deficits.

Subcortical auditory neural synchronization is deficient in pre-reading children who develop dyslexia.

Auditory processing of temporal information in speech is sustained by synchronized firing of neurons along the entire auditory pathway. In school-aged children and adults with dyslexia, neural synchronization deficits have been found at cortical levels of the auditory system, however, these deficits do not appear to be present in pre-reading children. An alternative role for subcortical synchronization in reading development and dyslexia has been suggested, but remains debated. By means of a longitudinal study, we assessed cognitive reading-related skills and subcortical auditory steady-state responses (80 Hz ASSRs) in a group of children before formal reading instruction (pre-reading), after 1 year of formal reading instruction (beginning reading), and after 3 years of formal reading instruction (more advanced reading). Children were retrospectively classified into three groups based on family risk and literacy achievement: typically developing children without a family risk for dyslexia, typically developing children with a family risk for dyslexia, and children who developed dyslexia. Our results reveal that children who developed dyslexia demonstrate decreased 80 Hz ASSRs at the pre-reading stage. This effect is no longer present after the onset of reading instruction, due to an atypical developmental increase in 80 Hz ASSRs between the pre-reading and the beginning reading stage. A forward stepwise logistic regression analysis showed that literacy achievement was predictable with an accuracy of 90.4% based on a model including three significant predictors, that is, family risk for dyslexia (R = .31), phonological awareness (R = .23), and 80 Hz ASSRs (R = .26). Given that (1) abnormalities in subcortical ASSRs preceded reading acquisition in children who developed dyslexia and (2) subcortical ASSRs contributed to the prediction of literacy achievement, subcortical auditory synchronization deficits may constitute a pre-reading risk factor in the emergence of dyslexia.