Atypical perceptual and neural processing of emotional prosodic changes in children with autism spectrum disorders

Objective

The present study explored the processing of emotional speech prosody in school-aged children with autism spectrum disorders (ASD) but without marked language impairments (children with ASD [no LI]).

The discrimination of and orienting to speech and non-speech sounds in children with autism

The present study aimed to find out how different stages of cortical auditory processing (sound encoding, discrimination, and orienting) are affected in children with autism. To this end, auditory event-related potentials (ERP) were studied in 15 children with autism and their controls. Their responses were recorded for pitch, duration, and vowel changes in speech stimuli, and for corresponding changes in the non-speech counterparts of the stimuli, while the children watched silent videos and ignored the stimuli. The responses to sound repetition were diminished in amplitude in the children with autism, reflecting impaired sound encoding. The mismatch negativity (MMN), an ERP indexing sound discrimination, was enhanced in the children with autism as far as pitch changes were concerned. This is consistent with earlier studies reporting auditory hypersensitivity and good pitch-processing abilities, as well as with theories proposing enhanced perception of local stimulus features in individuals with autism. The discrimination of duration changes was impaired in these children, however. Finally, involuntary orienting to sound changes, as reflected by the P3a ERP, was more impaired for speech than non-speech sounds in the children with autism, suggesting deficits particularly in social orienting. This has been proposed to be one of the earliest symptoms to emerge, with pervasive effects on later development.     

Neurophysiological responses to faces and gaze direction differentiate children with ASD,ADHD and ASD + ADHD

Children with autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) demonstrate face processing abnormalities that may underlie social impairment. Despite substantial overlap between ASD and ADHD, ERP markers of face and gaze processing have not been directly compared across pure and comorbid cases. Children with ASD (n = 19), ADHD (n = 18), comorbid ASD + ADHD (n = 29) and typically developing (TD) controls (n = 26) were presented with upright/inverted faces with direct/averted gaze, with concurrent recording of the P1 and N170 components. While the N170 was predominant in the right hemisphere in TD and ADHD, children with ASD (ASD/ASD + ADHD) showed a bilateral distribution. In addition, children with ASD demonstrated altered response to gaze direction on P1 latency and no sensitivity to gaze direction on midline-N170 amplitude compared to TD and ADHD. In contrast, children with ADHD (ADHD/ASD + ADHD) exhibited a reduced face inversion effect on P1 latency compared to TD and ASD. These findings suggest children with ASD have specific abnormalities in gaze processing and altered neural specialisation, whereas children with ADHD show abnormalities at early visual attention stages. Children with ASD + ADHD are an additive co-occurrence with deficits of both disorders. Elucidating the neural basis of the overlap between ASD and ADHD is likely to inform aetiological investigation and clinical assessment.     

Expanding our understanding of sensory gating in children with autism spectrum disorders

ObjectiveThis study examined sensory gating in children with autism spectrum disorders (ASD). Gating is usually examined at the P50 component and rarely at mid- and late-latency components.MethodsElectroencephalography data were recorded during a paired-click paradigm, from 18 children with ASD (5–12 years), and 18 typically-developing (TD) children. Gating was assessed at the P50, N1, P2, and N2 event-related potential components. Parents of all participants completed the Short Sensory Profile (SSP).ResultsTD children showed gating at all components while children with ASD showed gating only at P2 and N2. Compared to TD children, the ASD group showed significantly reduced gating at P50, N1, and P2. No group differences were found at N2, suggesting typical N2 gating in the ASD group. Time-frequency analyses showed reduced orientation and neural synchronization of auditory stimuli. P50 and N1 gating significantly correlated with the SSP.ConclusionAlthough children with ASD have impaired early orientation and filtering of auditory stimuli, they exhibited gating at P2 and N2 components suggesting use of different gating mechanisms compared to TD children. Sensory deficits in ASD may relate to gating.SignificanceThe data provide novel evidence for impaired neural orientation, filtering, and synchronization in children with ASD.     

Auditory evoked potentials to speech and nonspeech stimuli are associated with verbal skills in preschoolers

Children’s obligatory auditory event-related potentials (ERPs) to speech and nonspeech sounds have been shown to associate with reading performance in children at risk or with dyslexia and their controls. However, very little is known of the cognitive processes these responses reflect. To investigate this question, we recorded ERPs to semisynthetic syllables and their acoustically matched nonspeech counterparts in 63 typically developed preschoolers, and assessed their verbal skills with an extensive set of neurocognitive tests. P1 and N2 amplitudes were larger for nonspeech than speech stimuli, whereas the opposite was true for N4. Furthermore, left-lateralized P1s were associated with better phonological and prereading skills, and larger P1s to nonspeech than speech stimuli with poorer verbal reasoning performance. Moreover, left-lateralized N2s, and equal-sized N4s to both speech and nonspeech stimuli were associated with slower naming. In contrast, children with equal-sized N2 amplitudes at left and right scalp locations, and larger N4s for speech than nonspeech stimuli, performed fastest. We discuss the possibility that children’s ERPs reflect not only neural encoding of sounds, but also sound quality processing, memory-trace construction, and lexical access. The results also corroborate previous findings that speech and nonspeech sounds are processed by at least partially distinct neural substrates.     

Atypical processing of auditory temporal complexity in autistics

Autistics exhibit a contrasting combination of auditory behavior, with enhanced pitch processing abilities often coexisting with reduced orienting towards complex speech sounds. Based on an analogous dissociation observed in vision, we expected that autistics’ auditory behavior with respect to complex sound processing may result from atypical activity in non-primary auditory cortex. We employed fMRI to explore the neural basis of complex non-social sound processing in 15 autistic and 13 non-autistics, using a factorial design in which auditory stimuli varied in spectral and temporal complexity. Spectral complexity was modulated by varying the harmonic content, whereas temporal complexity was modulated by varying frequency modulation depth. The detection task was performed similarly by autistics and non-autistics. In both groups, increasing spectral or temporal complexity was associated with activity increases in primary (Heschl's gyrus) and non-primary (anterolateral and posterior superior temporal gyrus) auditory cortex Activity was right-lateralized for spectral and left-lateralized for temporal complexity. Increasing temporal complexity was associated with greater activity in anterolateral superior temporal gyrus in non-autistics and greater effects in Heschl's gyrus in autistics. While we observed similar hierarchical functional organization for auditory processing in both groups, autistics exhibited diminished activity in non-primary auditory cortex and increased activity in primary auditory cortex in response to the presentation of temporally, but not of spectrally complex sounds. Greater temporal complexity effects in regions sensitive to acoustic features and reduced temporal complexity effects in regions sensitive to more abstract sound features could represent a greater focus towards perceptual aspects of speech sounds in autism.     

Multisensory integration of speech sounds with letters vs. visual speech: only visual speech induces the mismatch negativity

Numerous studies have demonstrated that the vision of lip movements can alter the perception of auditory speech syllables (McGurk effect). While there is ample evidence for integration of text and auditory speech, there are only a few studies on the orthographic equivalent of the McGurk effect. Here, we examined whether written text, like visual speech, can induce an illusory change in the perception of speech sounds on both the behavioural and neural levels. In a sound categorization task, we found that both text and visual speech changed the identity of speech sounds from an /aba/‐/ada/ continuum, but the size of this audiovisual effect was considerably smaller for text than visual speech. To examine at which level in the information processing hierarchy these multisensory interactions occur, we recorded electroencephalography in an audiovisual mismatch negativity (MMN, a component of the event‐related potential reflecting preattentive auditory change detection) paradigm in which deviant text or visual speech was used to induce an illusory change in a sequence of ambiguous sounds halfway between /aba/ and /ada/. We found that only deviant visual speech induced an MMN, but not deviant text, which induced a late P3‐like positive potential. These results demonstrate that text has much weaker effects on sound processing than visual speech does, possibly because text has different biological roots than visual speech.     

Brief report: Attention patterns to non-social stimuli and associations with sensory features in autistic children

BackgroundAberrant attention patterns have been commonly reported in autistic children. However, few studies have examined attention to non-social stimuli varying in salience and complexity using eye-tracking technology, as well as their links to clinical sensory features.MethodForty-one children [16 with autism spectrum disorder (ASD), 10 with developmental delay (DD), and 15 neurotypical (NT)] ages 4 to 13 years were included in this cross-sectional study. Children completed a passive-viewing eye-tracking task designed to measure visual attention (e.g., fixation duration and count) to non-social stimuli with sensory qualities involving motion (spinning or non-spinning) and sound. Parents completed a clinical questionnaire about their child’s sensory behaviors. Eye-tracking metrics were compared across stimulus conditions and diagnostic groups, and their associations with parent-report sensory features were examined.ResultsOverall children showed longer fixation durations and fewer fixation counts to more complex stimuli (e.g., moving or spinning objects), but such facilitatory effects of stimulus properties tended to be less evident in DD versus ASD or NT groups. More clinical sensory features, especially hyperresponsiveness, were moderately to highly associated with quicker initial fixations and longer fixation durations across stimulus conditions in ASD, but not in DD and NT groups.ConclusionThe overall attention and initial orientation to non-social stimuli were comparable across autistic children and their non-autistic peers, with some sensory properties such as dynamic motion producing a facilitatory effect (i.e., fewer fixations of longer durations) on attention. However, sensory differences, particularly hyperresponsiveness, might underlie attention patterns as impacted by stimulus properties specifically in autism.     

Repetitive and Stereotyped Behaviors in Children with Autism Spectrum Disorders in the Second Year of Life

This study examined repetitive and stereotyped behaviors (RSB) in children with autism spectrum disorders (ASD, n = 50), developmental delays without ASD (DD; n = 25) and typical development (TD, n = 50) between 18 and 24 months of age. Children with ASD demonstrated significantly higher frequency and longer duration of RSB with objects, body, and sensory behaviors during a systematic behavior sample than both the DD and TD groups. RSB with objects were related to concurrent measures of symbolic capacity and social competence in the second year and predicted developmental outcomes as well as severity of autism symptoms at 3 years in children with communication delays. RSB in the second year appear to be important for early identification and prediction of developmental outcomes.     

No evidence for impaired multisensory integration of low-level audiovisual stimuli in adolescents and young adults with autism spectrum disorders

Abrupt click sounds can improve the visual processing of flashes in several ways. Here, we examined this in high functioning adolescents with Autism Spectrum Disorders (ASD) using three tasks: (1) a task where clicks improve sensitivity for visual temporal order (temporal ventriloquism); (2) a task where a click improves visual search (pip-and-pop), and (3) a task where a click speeds up the visual orienting to a peripheral target (clock reading). Adolescents with ASD were, compared to adolescents with typical development (TD), impaired in judgments of visual temporal order, but they were unimpaired in visual search and orienting. Importantly, in all tasks visual performance of the ASD group improved by the presence of clicks by at least equal amounts as in the TD group. This suggests that adolescents and young adults with ASD show no generalized deficit in the multisensory integration of low-level audiovisual stimuli and/or the phasic alerting by abrupt sounds.     

Familiar Face Recognition in Children with Autism: The Differential use of Inner and Outer Face Parts

We investigated whether children with autistic spectrum disorders (ASD) have a deficit in recognising familiar faces. Children with ASD were given a forced choice familiar face recognition task with three conditions: full faces, inner face parts and outer face parts. Control groups were children with developmental delay (DD) and typically developing (TD) children. Children with ASD and children with DD recognised slightly fewer faces than did TD children, but there was no ASD-specific deficit. All groups displayed the same pattern of face part superiority: full-face superiority over inner face, and inner face superiority over outer face. Therefore, the pattern of familiar face recognition by children with ASD was similar to the pattern found in other children.     

Disruptive Behavior Disorders in Adolescents With ASD: Comparisons to Youth With Intellectual Disability or Typical Cognitive Development

Dual diagnosis of autism spectrum disorder (ASD) and behavior problems and/or mental disorders has become increasingly recognized and studied. Reported rates in samples of mixed-age youth with ASD are often above 70%, making this comorbidity more the rule than the exception. The present study compared rates of disruptive behavior disorder diagnosis in a sample of 13-year-old adolescents with ASD (n = 58), intellectual disability (ID; n = 40), or typical cognitive development (TD; n = 100). In youth without ASD, there was a high negative correlation between IQ and disruptive behavior disorders, assessed with the Child Behavior Checklist (CBCL) and the Diagnostic Interview Schedule for Children (DISC). In youth with ASD, however, the presence of a comorbid disruptive behavior disorder was unrelated to IQ, indicating that higher intelligence was not a protective factor for disruptive behavior disorders (DBDs) in ASD. On four CBCL scales and two DISC scales examined, youth with ASD had significantly higher rates than TD youth, though not generally higher than youth with ID. The most commonly diagnosed comorbid disorder in the early adolescents with ASD was attention-deficit/hyperactivity disorder. This has implications for planning school-based interventions, particularly for high-functioning children with ASD who are more likely to be fully included in general education.     

The First Year Inventory: Retrospective Parent Responses to a Questionnaire Designed to Identify One-Year-Olds at Risk for Autism

The First Year Inventory (FYI) is a parent questionnaire designed to assess behaviors in 12-month-olds that suggest risk for an eventual diagnosis of autism. We examined the construct validity of the FYI by comparing retrospective responses of parents of preschool children with autism spectrum disorders (ASD; n = 38), other developmental disabilities (DD; n = 15), and typical development (TD; n = 40). Children with ASD were rated at significantly higher risk on the FYI than children with DD or TD. The DD group was at intermediate risk, also significantly higher than the TD group. These retrospective data strengthen the validity of the FYI and have implications for refining the FYI to improve its utility for prospective screening of 12-month-olds.     

Effects of Background Noise on Cortical Encoding of Speech in Autism Spectrum Disorders

This study provides new evidence of deficient auditory cortical processing of speech in noise in autism spectrum disorders (ASD). Speech-evoked responses (~100–300 ms) in quiet and background noise were evaluated in typically-developing (TD) children and children with ASD. ASD responses showed delayed timing (both conditions) and reduced amplitudes (quiet) compared to TD responses. As expected, TD responses in noise were delayed and reduced compared to quiet responses. However, minimal quiet-to-noise response differences were found in children with ASD, presumably because quiet responses were already severely degraded. Moreover, ASD quiet responses resembled TD noise responses, implying that children with ASD process speech in quiet only as well as TD children do in background noise.     

Gray and white matter brain chemistry in young children with autism

CONTEXT: The brain pathophysiological abnormalities underlying autism remain unclear. Neuroimaging and histological studies suggest cellular abnormalities early in the course of the disease. OBJECTIVE: To measure the in vivo chemical profile of gray and white matter tissues in autism. DESIGN: Cross-sectional spectroscopic imaging study comparing 3- to 4-year-old children with autism spectrum disorder (ASD) with age-matched comparison groups of children with delayed development (DD) and typical development (TD). SETTING: The University of Washington Diagnostic Imaging Sciences Center, Seattle. PARTICIPANTS: Forty-five 3- to 4-year-old children with ASD, 12 age-matched children with DD, and 10 age-matched children with TD. MAIN OUTCOME MEASURES: Estimates of gray and white matter concentrations for choline-containing compounds (Cho), creatine plus phosphocreatine, N-acetylaspartate (NAA), and myo-inositol (mI). Transverse relaxation times for Cho, creatine plus phosphocreatine, and NAA expressed relative to control subjects with TD were examined to evaluate tissue compactness. RESULTS: The children with ASD demonstrated decreased gray matter concentrations of Cho (P < .001), creatine plus phosphocreatine (P = .02), NAA (P = .02), and mI (P = .008) compared with children with TD. Gray matter Cho transverse relaxation was also prolonged for the ASD sample compared with the TD group (P = .01). The children with ASD demonstrated significantly decreased levels of Cho (P = .04) and mI (P = .008) and trend-level NAA (P = .09) in gray matter compared with the DD group. For white matter, both children with ASD and children with DD showed a similar pattern of NAA and mI level decreases (for children with ASD vs children with TD: NAA, P = .03; mI, P = .04; for children with DD vs children with TD, NAA, P = .03; mI, P = .07). In several analyses, cerebral volume contributed significantly as a covariate. CONCLUSIONS: Reduced gray matter chemical concentrations and altered Cho transverse relaxation, in a pattern distinct from that in children with DD, suggest decreased cellularity, or density, at this early time point in ASD. Possibly reflecting shared developmental features, white matter results were common to ASD and DD groups. The relationship between cerebral volume and neurochemistry at this early time point may indicate processes related to unit scaling.     

Different,difficult or distinct? Mothers' and fathers' perceptions of temperament in children with and without intellectual disabilities

Background Can ratings of temperament be a way of identifying young children with intellectual disabilities (ID) who are at risk for being experienced as difficult? We aimed to explore parents' reports of temperament in their young children with or without ID, as well as positive and negative impact of the child on parents. Method Mothers and fathers of 55 children recently diagnosed with ID and 183 age‐matched typically developing (TD) children completed the EASI Temperamental Survey and two scales of the Family Impact Questionnaire measuring positive and negative impact of the child on parents. Results Parents rated children with mixed ID/DD (developmental delay) as shyer and more impulsive, and less active and sociable when compared with TD children. Children with mixed ID/DD were also reported to have more negative and less positive impact on the family compared with the TD group. In subgroup analyses, children with Down syndrome and cerebral palsy/motor impairment were described as having less negative impact on parents and were described as low in negative emotionality. Children with autism spectrum disorder (ASD), ID/DD nos and other less common diagnoses had a similar pattern of temperament with high emotionality, shyness and impulsivity, and low activity and sociability. Parents of children with ASD and ID/DD reported the highest level of negative impact. Conclusions Temperamental characteristics such as high negative emotionality and impulsivity, which can be identified earlier than behavioural problems, could be indicators of negative impact on parents of young children with ID. Despite great variability in temperament among children with mixed ID/DD, results indicated common temperamental characteristics among children with ASD, ID/DD and other diagnosis.     

Attentional Learning Helps Language Acquisition Take Shape for Atypically Developing Children,Not Just Children with Autism Spectrum Disorders

The shape bias—generalising labels to same shaped objects—has been linked to attentional learning or referential intent. We explore these origins in children with typical development (TD), autism spectrum disorders (ASD) and other developmental disorders (DD). In two conditions, a novel object was presented and either named or described. Children selected another from a shape, colour or texture match. TD children choose the shape match in both conditions, children with DD and ‘high-verbal mental age’ (VMA) children with ASD (language age > 4.6) did so in the name condition and ‘low-VMA’ children with ASD never showed the heuristic. Thus, the shape bias arises from attentional learning in atypically developing children and is delayed in ASD.     

Deconvolution of magnetic acoustic change complex (mACC)

ObjectiveThe aim of this study was to design a novel experimental approach to investigate the morphological characteristics of auditory cortical responses elicited by rapidly changing synthesized speech sounds.MethodsSix sound-evoked magnetoencephalographic (MEG) responses were measured to a synthesized train of speech sounds using the vowels /e/ and /u/ in 17 normal hearing young adults. Responses were measured to: (i) the onset of the speech train, (ii) an F0 increment; (iii) an F0 decrement; (iv) an F2 decrement; (v) an F2 increment; and (vi) the offset of the speech train using short (jittered around 135 ms) and long (1500 ms) stimulus onset asynchronies (SOAs). The least squares (LS) deconvolution technique was used to disentangle the overlapping MEG responses in the short SOA condition only.ResultsComparison between the morphology of the recovered cortical responses in the short and long SOAs conditions showed high similarity, suggesting that the LS deconvolution technique was successful in disentangling the MEG waveforms. Waveform latencies and amplitudes were different for the two SOAs conditions and were influenced by the spectro-temporal properties of the sound sequence. The magnetic acoustic change complex (mACC) for the short SOA condition showed significantly lower amplitudes and shorter latencies compared to the long SOA condition. The F0 transition showed a larger reduction in amplitude from long to short SOA compared to the F2 transition. Lateralization of the cortical responses were observed under some stimulus conditions and appeared to be associated with the spectro-temporal properties of the acoustic stimulus.ConclusionsThe LS deconvolution technique provides a new tool to study the properties of the auditory cortical response to rapidly changing sound stimuli. The presence of the cortical auditory evoked responses for rapid transition of synthesized speech stimuli suggests that the temporal code is preserved at the level of the auditory cortex. Further, the reduced amplitudes and shorter latencies might reflect intrinsic properties of the cortical neurons to rapidly presented sounds.SignificanceThis is the first demonstration of the separation of overlapping cortical responses to rapidly changing speech sounds and offers a potential new biomarker of discrimination of rapid transition of sound.     

Familiarity affects the processing of task-irrelevant auditory deviance

The effects of familiarity on auditory change detection on the basis of auditory sensory memory representations were investigated by presenting oddball sequences of sounds while participants ignored the auditory stimuli. Stimulus sequences were composed of sounds that were familiar and sounds that were made unfamiliar by playing the same sounds backward. The roles of frequently presented stimuli (standards) and infrequently presented ones (deviants) were fully crossed. Deviants elicited the mismatch negativity component of the event-related brain potential. We found an enhancement in detecting changes when deviant sounds appeared among familiar standard sounds compared when they were delivered among unfamiliar standards. Familiarity with the deviant sounds also enhanced the change-detection process. We suggest that tuning to familiar items sets up preparatory processes that affect change detection in familiar sound sequences.     

Relationship of autistic traits between parents and children with and without autism spectrum disorder

BackgroundAlthough parents with a child with autism spectrum disorder (ASD) have usually been identified as having the “broader autism phenotype”, empirical research on the differences in autistic-like characteristics between parents with and without ASD children has yielded inconsistent results.MethodThis survey of the autistic traits of parents and children was conducted in 119 parents with ASD children and 108 parents with typically developing (TD) children. Parents’ autistic traits were quantified using the Autism-Spectrum Quotient and children’s autistic traits were quantified using the Autism Spectrum Quotient—Children’s Version.ResultsThe autistic traits of ASD children were significantly higher than those of the TD children; however, autistic traits were similar between parents in the two groups. Furthermore, the correlations of autistic traits between parents and children were only significant for the TD group and not for the ASD group.ConclusionsThe current findings indicate that the relationship of autistic traits between parents and children exists in the TD group, and that the Autism-Spectrum Quotient may be used for parents as a screening aid to identify children who should be further screened for autistic traits.