Long-term effect of middle ear disease on temporal processing and P300 in two different populations of children.

BACKGROUND/OBJECTIVE: The effects of otitis media on the function of the central auditory nervous system in different populations is unknown. Understanding how the history of otitis media affects children from different nations will guide health professionals worldwide on the importance of adequate auditory stimulus in childhood. For this reason, the aim of the present study was to investigate the long-term auditory effects of middle ear disease on temporal processing and P300 in two different populations of children: Australian and Brazilian. METHODS: Temporal processing tests (Frequency Pattern Tests-FPT and Gaps in noise-GIN) and P300 were measured in 68 Brazilian and Australian children, aged between 8 to 14 years. The Brazilian otitis media group (BrOM) and Australian otitis media group (AusOM) consisted of 20 children each who had a documented history of otitis media. Control groups of 14 children (BrControl and AusControl) were also recruited from each country, all with no documented history of otitis media. RESULTS: The BrOM group showed significantly poorer performance (p<0.001) for FPT and the GIN compared to BrControl. The P300 response showed significantly longer mean latencies (p = 0.02) compared to BrControls. The AusOM group also showed significant delayed latency of P300 (p = 0.04) compared to the AusControl. The FPT showed significantly poorer performance (p = 0.04) compared to AusControls. The two otitis media groups showed no significant differences between each other on P300. Significant differences were seen however in temporal processing tests performance between the two cohorts for the otitis media groups. The BrOM group had significantly poorer responses (p<0.001) for FPT and GIN compared to the AusOM group. CONCLUSIONS: These findings support that although differences exist between BrOM and AusOM groups, otitis media can be demonstrated to affect the underlying mechanisms of the P300 measures and behavioral auditory responses in two different populations of children.

A Spectrotemporal Correlate of Language Impairment in Autism Spectrum Disorder.

This study introduces an objective neurophysiological marker of language ability, the integral of event-related desynchronization in the 5-20 Hz band during 0.2-1 seconds post auditory stimulation with interleaved word/non-word tokens. This measure correlates with clinical assessment of language function in both ASD and neurotypical pediatric populations. The measure does not appear related to general cognitive ability nor autism symptom severity (beyond degree of language impairment). We suggest that this oscillatory brain activity indexes lexical search and thus increases with increased search in the mental lexicon. While specificity for language impairment in ASD remains to be determined, such an objective index has potential utility in low functioning individuals with ASD and young children during language acquisition.

Evidence-based pathways to intervention for children with language disorders.

BACKGROUND: Paediatric speech and language therapist (SLT) roles often involve planning individualized intervention for specific children, working collaboratively with families and education staff, providing advice, training and coaching and raising awareness. A tiered approach to service delivery is currently recommended whereby services become increasingly specialized and individualized for children with greater needs. AIMS: To stimulate discussion regarding delivery of SLT services by examining evidence regarding the effectiveness of (1) intervention for children with language disorders at different tiers and (2) SLT roles within these tiers; and to propose an evidence-based model of SLT service delivery and a flowchart to aid clinical decision-making. METHODS & PROCEDURES: Meta-analyses and systematic reviews, together with controlled, peer-reviewed group studies where recent systematic reviews were not available, of interventions for children with language disorders are discussed, alongside the differing roles SLTs play in these interventions. Gaps in the evidence base are highlighted. MAIN CONTRIBUTION: The service-delivery model presented resembles the tiered model commonly used in education services, but divides individualized (Tier 3) services into Tier 3A: indirect intervention delivered by non-SLTs, and Tier 3B: direct intervention by an SLT. We report evidence for intervention effectiveness, which children might best be served by each tier, the role SLTs could take within each tier and the effectiveness of these roles. Regarding universal interventions provided to all children (Tier 1) and those targeted at children with language weaknesses or vulnerabilities (Tier 2), there is growing evidence that approaches led by education services can be effective when staff are highly trained and well supported. There is currently limited evidence regarding additional benefit of SLT-specific roles at Tiers 1 and 2. With regard to individualized intervention (Tier 3), children with complex or pervasive language disorders can progress following direct individualized intervention (Tier 3B), whereas children with milder or less pervasive difficulties can make progress when intervention is managed by an SLT, but delivered indirectly by others (Tier 3A), provided they are well trained and supported, and closely monitored. CONCLUSIONS & IMPLICATIONS: SLTs have a contribution to make at all tiers, but where prioritization for clinical services is a necessity, we need to establish the relative benefits and cost-effectiveness at each tier. Good evidence exists for SLTs delivering direct individualized intervention and we should ensure that this is available to children with pervasive and/or complex language disorders. In cases where service models are being provided which lack evidence, we strongly recommend that SLTs investigate the effectiveness of their approaches.

An Analysis of The Parameters Used In Speech ABR Assessment Protocols.

The aim of this study was to assess the parameters of choice, such as duration, intensity, rate, polarity, number of sweeps, window length, stimulated ear, fundamental frequency, first formant, and second formant, from previously published speech ABR studies. To identify candidate articles, five databases were assessed using the following keyword descriptors: speech ABR, ABR-speech, speech auditory brainstem response, auditory evoked potential to speech, speech-evoked brainstem response, and complex sounds. The search identified 1288 articles published between 2005 and 2015. After filtering the total number of papers according to the inclusion and exclusion criteria, 21 studies were selected. Analyzing the protocol details used in 21 studies suggested that there is no consensus to date on a speech-ABR protocol and that the parameters of analysis used are quite variable between studies. This inhibits the wider generalization and extrapolation of data across languages and studies.

A new measure of child vocal reciprocity in children with autism spectrum disorder.

Children's vocal development occurs in the context of reciprocal exchanges with a communication partner who models "speechlike" productions. We propose a new measure of child vocal reciprocity, which we define as the degree to which an adult vocal response increases the probability of an immediately following child vocal response. Vocal reciprocity is likely to be associated with the speechlikeness of vocal communication in young children with autism spectrum disorder (ASD). Two studies were conducted to test the utility of the new measure. The first used simulated vocal samples with randomly sequenced child and adult vocalizations to test the accuracy of the proposed index of child vocal reciprocity. The second was an empirical study of 21 children with ASD who were preverbal or in the early stages of language development. Daylong vocal samples collected in the natural environment were computer analyzed to derive the proposed index of child vocal reciprocity, which was highly stable when derived from two daylong vocal samples and was associated with speechlikeness of vocal communication. This association was significant even when controlling for chance probability of child vocalizations to adult vocal responses, probability of adult vocalizations, or probability of child vocalizations. A valid measure of children's vocal reciprocity might eventually improve our ability to predict which children are on track to develop useful speech and/or are most likely to respond to language intervention. A link to a free, publicly-available software program to derive the new measure of child vocal reciprocity is provided. Autism Res 2018, 11: 903-915. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Children and adults often engage in back-and-forth vocal exchanges. The extent to which they do so is believed to support children's early speech and language development. Two studies tested a new measure of child vocal reciprocity using computer-generated and real-life vocal samples of young children with autism collected in natural settings. The results provide initial evidence of accuracy, test-retest reliability, and validity of the new measure of child vocal reciprocity. A sound measure of children's vocal reciprocity might improve our ability to predict which children are on track to develop useful speech and/or are most likely to respond to language intervention. A free, publicly-available software program and manuals are provided.

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.

Correlation between Voice and Auditory Processing.

PURPOSE: To compare and to correlate the performance of women with behavioral dysphonia and without voice disorders in auditory processing tests and in the Voice Tone Reproduction Test (VTRT). METHODS: Forty women aged from 18 to 44 years participated and were divided in two groups: dysphonic (DG) and non-dysphonic (NDG). The participants underwent interview, hearing, otorhinolaryngology and voice assessments (voice record, VTRT through phonetography), and auditory processing assessment-using the Pitch Pattern Sequence (PPS) test and the Duration Pattern Sequence (DPS) test. The statistical analysis compared both groups, and there was a correlation test (P < 0.05). RESULTS: The NDG had a better performance in the PPS test (P = 0.000), in the VTRT test in the first attempt (P = 0.025), and in the total of correct answers (P = 0.017). There was a positive correlation between the PPS and both the first attempt of the VTRT and the total number of attempts. Regarding the DPS, there was a positive correlation for the left ear with the total number of VTRT attempts. CONCLUSIONS: Dysphonic women presented disorders in temporal auditory processing skills, revealing an important relation between vocal production and impairment of some central auditory functions. There was a positive correlation between the performance in the auditory processing assessment and the performance in voice tone reproduction in both groups. The VTRT may assist speech therapists and voice trainers in verifying difficulties of auditory perception of dysphonic women when the cause is due to behavioral tdysphonia.

Abnormalities in cortical auditory responses in children with central auditory processing disorder.

The main objective of the present study was to identify markers of neural deficits in children with central auditory processing disorder (CAPD) by measuring latency and amplitude of the auditory cortical responses and mismatch negativity (MMN) responses. Passive oddball paradigms were used with nonverbal and verbal stimuli to record cortical auditory-evoked potentials and MMN. Twenty-three children aged 9-12 participated in the study: 10 with normal hearing acuity as well as CAPD and 13 with normal hearing without CAPD. No significant group differences were observed for P1 latency and amplitude. Children with CAPD were observed to have significant N2 latency prolongation and amplitude reduction with nonverbal and verbal stimuli compared to children without CAPD. No significant group differences were observed for the MMN conditions. Moreover, electrode position affected the results in the same manner for both groups of children. The findings of the present study suggest that the N2 response could be a marker of neural deficits in children with CAPD. N2 results suggest that maturational factors or a different mechanism could be involved in processing auditory information at the central level for these children.

[Acoustic reflexes of children with and without central auditory processing disorders]. / Stapediusreflexe von Kindern mit und ohne auditive Verarbeitungs- und Wahrnehmungsstörungen.

BACKGROUND: According to international standards, determination of acoustic reflex thresholds (ART) is one of the established objective measurements in the diagnostic workup of central auditory processing disorders (CAPD). However, there is still no evidence for the significance of ART in CAPD diagnosis. PATIENTS AND METHODS: This study tested 57 children with proven CAPD and 50 healthy children (control group) with regard to group differences in mean ART (sine tones or bandpass-filtered noise). Additionally, it was investigated whether there were group differences between the mean dissociations of ART for sine tones or bandpass filtered noise. RESULTS: Neither ipsi- nor contralaterally were significant clinically relevant group differences (p < 0.050) between the mean ART of children with and without CAPD found. After Bonferroni correction, a significant group difference in the percentage of non-triggered reflexes was only observed with left-sided contralateral 2 kHz stimuli. Concerning the number of dissociations ≥20 dB, no significant group differences (p < 0.050) were detected either ipsi- or contralaterally (Fisher's test). CONCLUSION: The results of the study seem to indicate no clinically relevant ability of ART measurements to distinguish between children with and without CAPD. This renders the benefit of ART measurements for CAPD diagnosis questionable.

Developmental changes in brain response to speech perception in late-talking children: A longitudinal MMR study.

This study used a longitudinal design to examine the development of mismatch responses (MMRs) to Mandarin lexical tones, an index of neural speech discriminative responses, in late talkers and typical controls at 3, 5, and 6 years of age. Lexical tones are phonetic suprasegments that distinguish the lexical meanings of syllables in tonal languages. The 2 year-old late talkers were later divided into persistent language delay and late bloomer groups according to their performance on standardized language tests at 4 years. Results showed that children with persistent language delay demonstrated more positive mismatch responses than the typical controls at 3 years of age. At the age of 5, no group difference were found in the amplitude of MMRs, but the maturation of MMRs could be observed in the change of topography, with more prominent negative response in the frontal sites only in the typical group. Correlations were found between the index of MMRs at 3 years and children's language performance outcome at 6 years. Our results indicate that the development of fine-grained tone representations is delayed in late-talking children between 3 and 5 years and may be one of the underlying mechanisms which associated with later language performance.

Central auditory processing in patients with spinocerebellar ataxia.

BACKGROUND: Autosomal dominant spinocerebellar ataxias (SCAs) are a group of rare and heterogeneous neurodegenerative diseases characterized by the presence of progressive cerebellar ataxia. Although the symptomatology of SCAs is well known, information regarding central auditory functioning in these patients is lacking. Therefore, we assessed the central auditory processing disorders (CAPD) in patients with different subtypes of SCA. METHODS: In a retrospective cross-sectional study, we subjected 43 patients with SCAs to otorhinolaryngological, audiological, Brainstem Auditory Evoked Potential (BAEP) and acoustic immittance evaluations as well as CAPD tests, namely the Standard Spondaic Word (SSW) and the Random Gap Detection Test (RGDT). RESULTS: Most patients (83.7%) reported an imbalance when walking; many reported difficulty speaking (48.8%), dizziness (41.8%), and dysphagia (39.5%). In the audiometric test, 14/43 patients (32.5%) presented alterations, including 4/12 patients with SCA3 (33.3%), 1/8 patients with SCA2 (12.5%), 1/1 patient with SCA4 (100%), 1/1 patient with SCA6 (100%), 1/1 patient with SCA7 (100%), 3/6 patients with SCA10 (50%), and 3/14 patients with an undetermined type of SCA (21.4%). In the BAEP test, 20/43 patients (46.5%) presented alterations (11.6% na orelha esquerda e 34.9% bilateralmente), including 7/12 patients with SCA3 (58.3%), 5/8 patients with SCA2 (62.5%), 1/1 patient with SCA4 (100%), 1/1 patient with SCA6 (100%), 1/1 patient with SCA7 (100%), 4/6 patients with SCA10 (66.7%), and 2/14 patients with an undetermined type of SCA (14.2%). In the SSW, 22/40 patients (55%) presented alterations (2.5% in the right ear, 15% in the left ear, and 37.5% bilaterally), including 6/10 patients (60%) with SCA3, 3/8 (37.5%) with SCA2, 1/1 (100%) with SCA4, 1/1 (100%) with SCA6, 1/1 (100%) with SCA7, 4/5 (80%) with SCA10, and 8/14 (57.1%) with an undetermined type SCA. For the RGDT, 30/40 patients (75%) presented alterations, including 8/10 (80%) with SCA3, 6/8 (75%) with SCA2, 1/1 (100%) with SCA4, 1/1 (100%) with SCA6, 1/1 (100%) with SCA7, 4/5 (80%) with SCA10, and 9/14 (64.3%) with an undetermined type of SCA. In immittance testing, 19/43 patients (44.1%) presented alterations, including 6/12 (50%) with SCA3, 4/8 (50%) with SCA2, 1/1 (100%) with SCA4, 1/1 (100%) with SCA6, 1/1 (100%) with SCA7, 2/6 (33.3%) with SCA10, and 4/14 (28.6%) with an undetermined type of SCA. CONCLUSIONS: A majority of patients exhibited SSW test deficits, with a predominance of bilateralism, and three-fourths had impaired RGDT performance, pointing to difficulties with binaural integration and temporal resolution. Assessment of CAPD is important for therapeutic follow ups in patients with SCA.

BioMARK as electrophysiological tool for assessing children at risk for (central) auditory processing disorders without reading deficits.

Biological Marker of auditory processing (BioMARK) is an electrophysiological test tool widely known as Speech-evoked ABR. Several previous investigations have shown the utility of speech-evoked ABR in the diagnosis of language based processing deficits like learning disability and specific language impairment; however missing from literature is a study that has ruled out the existence of comorbidity of such conditions and carefully delineated the efficacy of speech-evoked ABR in children with children with auditory processing disorders sans reading deficits. Hence, the present study aimed at investigating Speech-evoked ABR in children with auditory processing disorders without reading problems. A total of 336 school going children in the age range of 8-12 years were screened for presence of central auditory processing deficits. Among the 51 children who were identified as at risk, 15 were randomly selected and served as experimental group. The control group comprised of fifteen age matched children. The inter-group comparison was done using MANOVA, which revealed significant prolongations of latencies of waves V and A (p = 0.001) along with marginal reductions in V/A slope (p = 0.052) and amplitude of responses to first formant (p = 0.065). The responses to higher frequencies did not differ between the groups. Speech-evoked ABR are affected in children who are at risk of central auditory processing disorders sans reading deficits which probably indicates the presence of abnormal brainstem encoding of speech signal in this population.

Neuromagnetic oscillations predict evoked-response latency delays and core language deficits in autism spectrum disorders.

Previous studies have observed evoked response latency as well as gamma band superior temporal gyrus (STG) auditory abnormalities in individuals with autism spectrum disorders (ASD). A limitation of these studies is that associations between these two abnormalities, as well as the full extent of oscillatory phenomena in ASD in terms of frequency and time, have not been examined. Subjects were presented pure tones at 200, 300, 500, and 1,000 Hz while magnetoencephalography assessed activity in STG auditory areas in a sample of 105 children with ASD and 36 typically developing controls (TD). Findings revealed a profile such that auditory STG processes in ASD were characterized by pre-stimulus abnormalities across multiple frequencies, then early high-frequency abnormalities followed by low-frequency abnormalities. Increased pre-stimulus activity was a 'core' abnormality, with pre-stimulus activity predicting post-stimulus neural abnormalities, group membership, and clinical symptoms (CELF-4 Core Language Index). Deficits in synaptic integration in the auditory cortex are associated with oscillatory abnormalities in ASD as well as patient symptoms. Increased pre-stimulus activity in ASD likely demonstrates a fundamental signal-to-noise deficit in individuals with ASD, with elevations in oscillatory activity suggesting an inability to maintain an appropriate 'neural tone' and an inability to rapidly return to a resting state prior to the next stimulus.

Auditory scene analysis in school-aged children with developmental language disorders.

Natural sound environments are dynamic, with overlapping acoustic input originating from simultaneously active sources. A key function of the auditory system is to integrate sensory inputs that belong together and segregate those that come from different sources. We hypothesized that this skill is impaired in individuals with phonological processing difficulties. There is considerable disagreement about whether phonological impairments observed in children with developmental language disorders can be attributed to specific linguistic deficits or to more general acoustic processing deficits. However, most tests of general auditory abilities have been conducted with a single set of sounds. We assessed the ability of school-aged children (7-15 years) to parse complex auditory non-speech input, and determined whether the presence of phonological processing impairments was associated with stream perception performance. A key finding was that children with language impairments did not show the same developmental trajectory for stream perception as typically developing children. In addition, children with language impairments required larger frequency separations between sounds to hear distinct streams compared to age-matched peers. Furthermore, phonological processing ability was a significant predictor of stream perception measures, but only in the older age groups. No such association was found in the youngest children. These results indicate that children with language impairments have difficulty parsing speech streams, or identifying individual sound events when there are competing sound sources. We conclude that language group differences may in part reflect fundamental maturational disparities in the analysis of complex auditory scenes.

Fragile spectral and temporal auditory processing in adolescents with autism spectrum disorder and early language delay.

We investigated low-level auditory spectral and temporal processing in adolescents with autism spectrum disorder (ASD) and early language delay compared to matched typically developing controls. Auditory measures were designed to target right versus left auditory cortex processing (i.e. frequency discrimination and slow amplitude modulation (AM) detection versus gap-in-noise detection and faster AM detection), and to pinpoint the task and stimulus characteristics underlying putative superior spectral processing in ASD. We observed impaired frequency discrimination in the ASD group and suggestive evidence of poorer temporal resolution as indexed by gap-in-noise detection thresholds. These findings question the evidence of enhanced spectral sensitivity in ASD and do not support the hypothesis of superior right and inferior left hemispheric auditory processing in ASD.

Decreased sensitivity to long-distance dependencies in children with a history of specific language impairment: electrophysiological evidence.

PURPOSE: One possible source of tense and agreement limitations in children with specific language impairment (SLI) is a weakness in appreciating structural dependencies that occur in many sentences in the input. This possibility was tested in the present study. METHOD: Children with a history of SLI (H-SLI; n = 12; M = 9;7 [years;months]) and typically developing same-age peers (TD; n = 12; M = 9;7) listened to and made grammaticality judgments about grammatical and ungrammatical sentences involving either a local agreement error (e.g., "Every night they talks on the phone") or a long-distance finiteness error (e.g., "He makes the quiet boy talks a little louder"). Electrophysiological (ERP) and behavioral (accuracy) measures were obtained. RESULTS: Local agreement errors elicited the expected anterior negativity and P600 components in both groups of children. However, relative to the TD group, the P600 effect for the long-distance finiteness errors was delayed, reduced in amplitude, and shorter in duration for the H-SLI group. The children's grammaticality judgments were consistent with the ERP findings. CONCLUSION: Children with H-SLI seem to be relatively insensitive to the finiteness constraints that matrix verbs place on subject-verb clauses that appear later in the sentence.

Implementation of integrated mismatch negativity in differentiating children with specific language impairment.

OBJECTIVE: The study aimed to assess the use of Integrated Mismatch Negativity (MMNi) in differentiating children with specific language impairment (SLI) from a control group. DESIGN: Six conditions were created using a 1,000-Hz standard stimulus with three deviants of 1,020, 1,050, or 1,100 Hz and two interstimulus intervals of 400 and 200 ms. Recordings were processed offline using NeuroScan Edit (NeuroScan, Texas, United States). Four time analysis points were chosen and the magnitude of the integrated deviant was compared with the 100 standard subaverages. Mismatch negativity (MMN) presence was determined when 10 or less of the standard subaverages were less than the deviant subaverage magnitude. STUDY PARTICIPANTS: A total of 18 children with SLI and 35 typical development children participated in the study. RESULTS: Pearson chi-square test demonstrated that the proportion of MMN presence in the SLI group was not significantly different from the control group and it did not vary with condition. Two-way between-group analysis of variance confirmed that using 1,000 Hz standard, 1,050 Hz deviant, and 400 ms interstimulus interval was significantly different from the other conditions. CONCLUSION: MMNi does not serve as a tool for identifying children with SLI when using pure-tone stimuli. However, using different time analysis points with MMNi should be explored further, particularly with speech material.

Assessing auditory processing disorders in children with developmental dyslexia using auditory cognitive event-related potentials.

OBJECTIVES: It has been suggested that dyslexia is linked to a core cognitive deficit in phonological awareness tasks and/or in the processing of auditory stimuli. Auditory evoked potentials are a valid, objective measure of the accuracy of central auditory processing in humans. The aim of this study was to assess auditory evoked potentials in children with dyslexia. PATIENTS AND METHODS: Sixty-six children participated in the study. A set of hearing tests and the recording of complex event-related potentials (ERPs) were performed. RESULTS: Mixmatch negativity (MMN) and P300 waves were significantly more frequent in the healthy children (control group) than in children with dyslexia. The P300 wave was present in all subjects from the control group, the MMN wave in 92% of them. In the dyslexic group, complex ERPs were recorded roughly 33% of the time. Latencies of complex ERPs in children with dyslexia were greater than latencies in children in the control group. MMN and P300 maturation (change with age) was observed only for the control group. A wide range of MMN and P300 responses was observed across children with dyslexia. CONCLUSION: Complex ERPs may be useful in determining the condition of audiologic functions; however, on their own they are not sufficient to recognize dyslexia because of the heterogeneity of nonspecific changes.

A systematic review of electrophysiological outcomes following auditory training in school-age children with auditory processing deficits.

OBJECTIVE: To systematically review the peer-reviewed literature on electrophysiological outcomes following auditory training (AT) in school-age children with (central) auditory processing disorder ([C]APD). DESIGN: A systematic review. STUDY SAMPLE: Searches of 16 electronic databases yielded four studies involving school-aged children whose auditory processing deficits had been confirmed in a manner consistent with ASHA (2005) and AAA (2010) and compared to a treated and/or an untreated control group before and after AT. A further three studies were identified with one lacking a control group and two measuring auditory processing in a manner not consistent with ASHA (2005) and AAA (2010). RESULTS: There is limited evidence that AT leads to measurable electrophysiological changes in children with auditory processing deficits. CONCLUSION: The evidence base is too small and weak to provide clear guidance on the use of electrophysiological outcomes as a measure of AT outcomes in children with auditory processing problems. The currently limited data can only be used to suggest that click-evoked AMLR and tone-burst evoked auditory P300 might be more likely to detect such outcomes in children diagnosed with (C)APD, and that speech-evoked ALLR might be more likely to detect phonological processing changes in children without a specific diagnosis of (C)APD.

Abnormal subcortical components of the corticostriatal system in young adults with DLI: a combined structural MRI and DTI study.

Developmental Language Impairment (DLI) is a neurodevelopmental disorder affecting 12% to 14% of the school-age children in the United States. While substantial studies have shown a wide range of linguistic and non-linguistic difficulty in individuals with DLI, very little is known about the neuroanatomical mechanisms underlying this disorder. In the current study, we examined the subcortical components of the corticostriatal system in young adults with DLI, including the caudate nucleus, the putamen, the nucleus accumbens, the globus pallidus, and the thalamus. Additionally, the four cerebral lobes and the hippocampus were also comprised for an exploratory analysis. We used conventional magnetic resonance imaging (MRI) to measure regional brain volumes, as well as diffusion tensor imaging (DTI) to assess water diffusion anisotropy as quantified by fractional anisotropy (FA). Two groups of participants, one with DLI (n=12) and the other without (n=12), were recruited from a prior behavioral study, and all were matched on age, gender, and handedness. Volumetric analyses revealed region-specific abnormalities in individuals with DLI, showing pathological enlargement bilaterally in the putamen and the nucleus accumbens, and unilaterally in the right globus pallidus after the intracranial volumes were controlled. Regarding the DTI findings, the DLI group showed decreased FA values in the globus pallidus and the thalamus but these significant differences disappeared after controlling for the whole-brain FA value, indicating that microstructural abnormality is diffuse and affects other regions of the brain. Taken together, these results suggest region-specific corticostriatal abnormalities in DLI at the macrostructural level, but corticostriatal abnormalities at the microstructural level may be a part of a diffuse pattern of brain development. Future work is suggested to investigate the relationship between corticostriatal connectivity and individual differences in language development.