Post-stimulus rebound of EEG power in response to vocal and non-vocal sounds in children with and without autism spectrum disorder: An exploratory study.

BackgroundIndividuals with autism spectrum disorder (ASD) show a relative indifference to the human voice. Accordingly, and contrarily to their typically developed peers, adults with autism do not show a preferential response to voices in the superior temporal sulcus; this lack of voice-specific response was previously linked to atypical processing of voices. In electroencephalography, a slow event-related potential (ERP) called the fronto-temporal positivity to voice (FTPV) is larger for vocal than for non-vocal sounds, resulting in a voice-sensitive response over right fronto-temporal sites. Here, we investigated the neurophysiological correlates of voice perception in children with and without ASD.MethodsSixteen children with autism and 16 age-matched typically developing children heard vocal (speech and non-speech) and non-vocal sounds while their electroencephalographic activity was recorded; overall IQ was smaller in the group of children with ASD. ERP amplitudes were compared using non-parametric statistical tests at each electrode and in successive 20-ms time windows. Within each group, differences between conditions were assessed using a non-parametric Quade test between 0 and 400 ms post-stimulus. Inter-group comparisons of ERP amplitudes were performed using non-paired Kruskal-Wallis tests between 140 and 180 ms post-stimulus.ResultsTypically developing children showed the classical voice-sensitive response over right fronto-temporal electrodes, for both speech and non-speech vocal sounds. Children with ASD did not show a preferential response to vocal sounds. Inter-group analysis showed no difference in the processing of vocal sounds, both speech and non-speech, but significant differences in the processing of non-vocal sounds over right fronto-temporal sites.ConclusionsOur results demonstrate a lack of voice-preferential response in children with autism spectrum disorders. In contrast to observations in adults with ASD, the lack of voice-preferential response was attributed to an atypical response to non-vocal sounds, which was overall more similar to the event-related potentials evoked by vocal sounds in both groups. This result suggests atypical maturation processes in ASD impeding the specialization of temporal regions in voice processing.

A lack of response to voices, and a great interest for music are part of the behavioral expressions, commonly (self-)reported in Autism Spectrum Disorder (ASD). These atypical interests for vocal and musical sounds could be attributable to different levels of acoustical noise, quantified in the harmonic-to-noise ratio (HNR). No previous study has investigated explicit auditory pleasantness in ASD comparing vocal and non-vocal sounds, in relation to acoustic noise level. The aim of this study is to objectively evaluate auditory pleasantness. 16 adults on the autism spectrum and 16 neuro-typical (NT) matched adults rated the likeability of vocal and non-vocal sounds, with varying harmonic-to-noise ratio levels. A group by category interaction in pleasantness judgements revealed that participants on the autism spectrum judged vocal sounds as less pleasant than non-vocal sounds; an effect not found for NT participants. A category by HNR level interaction revealed that participants of both groups rated sounds with a high HNR as more pleasant for non-vocal sounds. A significant group by HNR interaction revealed that people on the autism spectrum tended to judge as less pleasant sounds with high HNR and more pleasant those with low HNR than NT participants. Acoustical noise level of sounds alone does not appear to explain atypical interest for voices and greater interest in music in ASD.

A relative indifference to the human voice is a characteristic of Autism Spectrum Disorder (ASD). Yet, studies of voice perception in ASD provided contradictory results: one study described an absence of preferential response to voices in ASD while another reported a larger activation to vocal sounds than environmental sounds, as seen in typically developed (TD) adults. In children with ASD, an absence of preferential response to vocal sounds was attributed to an atypical response to environmental sounds. To have a better understanding of these contradictions, we re-analyzed the data from sixteen children with ASD and sixteen age-matched TD children to evaluate both inter- and intra-subject variability. Intra-subject variability was estimated with a single-trial analysis of electroencephalographic data, through a measure of inter-trial consistency, which is the proportion of trials showing a positive activity in response to vocal and non-vocal sounds. Results demonstrate a larger inter-subject variability in response to non-vocal sounds, driven by a subset of children with ASD (7/16) who do not show the expected negative Tb peak in response to non-vocal sounds around 200 ms after the start of the stimulation due to a reduced inter-trial consistency. A logistic regression model with age and clinical parameters allowed demonstrating that not a single parameter discriminated the subgroups of ASD participants. Yet, the electrophysiologically-based groups differed on a linear combination of parameters. Children with ASD showing a reduced inter-trial consistency were younger and characterized by lower verbal developmental quotient and less attempt to communicate by voice. This data suggests that a lack of specialization for processing social signal may stem from an atypical processing of environmental sounds, linked to the development of general communication abilities. Discrepancy reported in the literature may arise from that heterogeneity and it may be inadequate to divide children with ASD based only on intellectual quotient or language abilities. This analysis could be a useful tool in providing complementary information for the functional diagnostic of ASD and evaluating verbal communication impairment.

Listen up! Processing of intensity change differs for vocal and nonvocal sounds

To investigate the temporal aspect of timbre processing, we recorded auditory-evoked neuromagnetic responses to periodic complex sounds, which were matched in all acoustic parameters except for two fundamental frequencies (F0s) and 12 spectral envelopes of vocal and nonvocal categories. Only for nonvocal sounds, a significant difference in N1m latency for F0 was detected in both hemispheres. A significant difference among stimuli was detected in both hemispheres for vocal and linear sounds, whereas only in the right hemisphere for instrumental sounds. Moreover, the results of paired comparison among F0s revealed that not only the vocal sounds but also some of the nonvocal sounds were F0-independent. This latency independence may be attributed to the relatively high power in the higher frequency spectrum.

Inherited and De Novo Genetic Risk for Autism Impacts Shared Networks.

Autism is linked to a strong need for sameness and difficulties in social communication, associated with atypical brain responses to voices and changes. This study aimed to characterize neural adaptation in autistic adults using a Roving paradigm and assess how vocal vs. non-vocal, as well as neutral vs. emotional sounds, influence this adaptation. Neural adaptation was measured in 20 autistic and 20 non-autistic adults using a Roving paradigm, where sounds were repeated 4, 8, or 14 times. Neural responses and Repetition Positivity (RP) amplitudes were analyzed as indices of adaptation. RP amplitudes showed no significant differences between groups for vocal or non-vocal sounds, but adaptation dynamics varied. Non-autistic adults adapted more quickly to non-vocal (5-8 repetitions) compared to vocal sounds (12-14 repetitions). In contrast, autistic adults adapt faster to vocal than to non-vocal sounds. Moreover emotional prosodic content influenced RP amplitude in autistic adults only, suggesting heightened sensitivity to emotional cues in social contexts. The study highlights how atypical neural adaptation in autism how emotional content impacts social communication deficits. These insights enhance understanding of autism-related adaptation challenges.

Pervasive social difficulties among individuals with autism spectrum disorder (ASD) are often construed as deriving from reduced sensitivity to social stimuli. Behavioral and neurobiological evidence suggests that typical individuals show preferential processing of social (e.g., voices, faces) over nonsocial (e.g., nonvocal sounds, images of objects) information, whereas individuals with ASD may not. This reduction in sensitivity may reflect disrupted reward processing [Dawson & Bernier, ], with significant developmental consequences for affected individuals. In this study, we explore effects of social and monetary reward on behavioral and electrodermal responses (EDRs) among 8- to 12-year-old boys with (n = 18) and without (n = 18) ASD, with attention to the potential moderating effects of stimulus familiarity. During a simple matching task, participants with and without ASD had marginally slower reactions during social vs. nonsocial reward, and boys with ASD had less accurate responses than controls. Compared to baseline, reward and non-reward conditions elicited more frequent and larger EDRs for participants as a whole, and both groups showed similar patterns of EDR change within reward blocks. However, boys with and without ASD differed in their EDRs to non-reward, and response amplitude was correlated with social and emotional functioning. These findings provide some support for altered reward responding in ASD at the autonomic level, and highlight the discontinuation of reward as an important component of reward-based learning that may play a role in shaping behavior and guiding specialized brain development to subserve social behavior and cognition across the lifespan.

For prelingually deaf children, cochlear implants (CIs) can restore auditory input to the auditory cortex and the ability to acquire spoken language. Language development is strongly intertwined with voice perception. The aim of this electrophysiological study was to investigate human voice processing using measures of cortical auditory evoked potentials (AEPs) in pediatric CI users. Cortical AEPs were measured in 8 CI children (4 to 12 years old) with good auditory and language performance and 8 normal-hearing (NH) age-matched controls. The auditory stimuli were nonspeech vocal sounds (laughing, sighing, coughing) and environmental sounds (e.g., telephones, alarms, cars, bells, water, wind). Independent component analysis was used to minimize the CI artifact in cortical AEPs. Fronto-temporal positivity to vocal sounds was found in NH children, with a significant effect in the 140 to 240 msec latency range. In CI children, there was a positive response to vocal sounds in the 170 to 250 msec latency range, with a more diffuse and anterior distribution than in the NH children. Cortical responses to vocal sounds were recorded in CI children. The topography and latency of response to voice differed from that of NH children. The results suggest that cortical reorganization for processing vocal sounds may occur in congenitally deaf children fitted with a CI.

Sensory processing dysfunction not only affects most individuals with autism spectrum disorder (ASD), but at least 5% of children without ASD also experience dysfunctional sensory processing. Our understanding of the relationship between sensory dysfunction and resting state brain activity is still emerging. This study compared long-range resting state functional connectivity of neural oscillatory behavior in children aged 8–12 years with autism spectrum disorder (ASD; N=18), those with sensory processing dysfunction (SPD; N=18) who do not meet ASD criteria, and typically developing control participants (TDC; N=24) using magnetoencephalography (MEG). Functional connectivity analyses were performed in the alpha and beta frequency bands, which are known to be implicated in sensory information processing. Group differences in functional connectivity and associations between sensory abilities and functional connectivity were examined. Distinct patterns of functional connectivity differences between ASD and SPD groups were found only in the beta band, but not in the alpha band. In both alpha and beta bands, ASD and SPD cohorts differed from the TDC cohort. Somatosensory cortical beta-band functional connectivity was associated with tactile processing abilities, while higher-order auditory cortical alpha-band functional connectivity was associated with auditory processing abilities. These findings demonstrate distinct long-range neural synchrony alterations in SPD and ASD that are associated with sensory processing abilities. Neural synchrony measures could serve as potential sensitive biomarkers for ASD and SPD.

Autism spectrum disorder (ASD) is clinically characterized by social communication difficulties as well as restricted and repetitive patterns of behavior. In addition, children with ASD are more likely to experience anxiety compared with their peers who do not have ASD. Recent studies suggest that atypical amygdala structure, a brain region involved in emotions, may be related to anxiety in children with ASD. However, the amygdala is a complex structure composed of heterogeneous subnuclei, and few studies to date have focused on how amygdala subnuclei relate to in anxiety in this population. The current sample consisted of 95 children with ASD and 139 non-autistic children, who underwent magnetic resonance imaging (MRI) and assessments for anxiety. The amygdala volumes were automatically segmented. Results indicated that children with ASD had elevated anxiety scores relative to peers without ASD. Larger basal volumes predicted greater anxiety in children with ASD, and this association was not seen in non-autistic children. Findings converge with previous literature suggesting ASD children suffer from higher levels of anxiety than non-autistic children, which may have important implications in treatment and interventions. Our results suggest that volumetric estimation of amygdala's subregions in MRI may reveal specific anxiety-related associations in children with ASD.

BACKGROUND: Autism Spectrum Disorder (ASD) is a developmental disability associated with difficulties in social communication and the presence of repetitive behaviors. Along with social impairments, motor deficits can be identified as another characteristic associated with ASD. Although gait deviations have been looked at in children with ASD, not much is known about how gait deviations may persist in college students with ASD. PURPOSE: To compare running gait deviations between college students with and without ASD METHODS: Ten college students participated in this study. Five participants had a diagnosis of ASD (age 21.5±2.9 years) and 5 participants did not have an ASD diagnosis and comprised a healthy control (CON) group (age 24±3.5 years). Each participant performed 3 running trials over a 7.62 meter distance. Kinematic data were collecting using a 12-camera 3D motion capture system. Stance and swing phase time, and hip, knee, and ankle angles at initial contact and at toe off were extracted for further analysis. Variables were compared between groups using independent t-tests. As this is a preliminary analysis with a small sample size, significance was set at α≤0.10. RESULTS: Individuals with and without ASD had similar lower extremity joint angles at initial contact (hip 60.21±13.13° ASD, 53.60±16.07° CON, p=0.53; knee 37.10±12.40° ASD, 43.48±3.30° CON, p=0.36; ankle 17.66±4.89° ASD, 18.18±6.47° CON, p=0.90). The two groups also demonstrated similar knee and ankle angles at toe off (knee 24.51±3.86° ASD, 19.36±4.28° CON, p=0.11; ankle -15.74± 6.45° ASD, -13.22±10.32° CON, p=0.69), but the ASD group demonstrated less hip extension at toe off (2.97±1.07° ASD, -2.02±4.60° CON, p=0.07). The ASD group also demonstrated longer stance phases (0.29±0.03s ASD, 0.23±0.02s CON, p=0.02) and shorter swing phases (0.40±0.05s ASD, 0.47±0.05s CON, p=0.10) compared to the control group. CONCLUSION: The control group demonstrated more hip extension at toe off, which could suggest greater forward propulsion of the body. Greater propulsion is also associated with shorter ground contact times, and requires greater stability. The ASD group exhibited greater time in stance phase, and less time in swing phase, which could suggest potential balance deficits and less effective running patterns in college students with ASD.

Autism spectrum disorder is a neurodevelopmental condition characterized by social communication difficulties and restricted repetitive behaviors. Individuals with autism spectrum disorder are often diagnosed with other psychiatric conditions, including attention deficit hyperactivity disorder, anxiety, and depression. However, research on post-traumatic stress disorder among individuals with autism spectrum disorder is scarce. Nonetheless, studies have shown that those with autism spectrum disorder may face an increased risk of exposure to traumatic events. Separate lines of research in autism spectrum disorder and post-traumatic stress disorder have shown that the two may share several vulnerability factors. One of those is ruminative thinking, that is, one's tendency to re-hash thoughts and ideas, in a repetitive manner. This article examined the role of two rumination types as potential factors connecting autism spectrum disorder and post-traumatic stress disorder: brooding (continuously comparing one's current condition to one's desired condition) and reflection (an introspective effort to cognitively solve one's problems). A total of 34 adults with autism spectrum disorder (with no intellectual impairment) and 66 typically developing adults completed questionnaires assessing post-traumatic stress disorder symptoms and rumination. The results showed increased post-traumatic stress disorder symptoms in adults with autism spectrum disorder, compared to typically developing adults. Brooding rumination was also higher among those with autism spectrum disorder. Finally, brooding, but not reflection, served as a mechanism connecting autism spectrum disorder and post-traumatic stress disorder, that is, those with autism spectrum disorder showed increased brooding, which in turn predicted more post-traumatic stress disorder symptoms. This study has potential clinical implications. Rumination and cognitive inflexibility, which are common in autism spectrum disorder, could exacerbate post-traumatic symptoms among individuals with autism spectrum disorder who experience traumatic events. Interventions targeting brooding rumination and cognitive flexibility may assist in alleviating post-traumatic symptoms in individuals with autism spectrum disorder.

Multiscale static and dynamic brain functional network analysis reveals aberrant connectivity patterns in preschool children with autism spectrum disorder.

Autism spectrum disorder (ASD) is characterized by etiological and phenotypic heterogeneity. Despite efforts to categorize ASD into subtypes, research on specific functional connectivity changes within ASD subgroups based on clinical presentations is limited. This study proposed a symptom-based clustering approach to identify subgroups of ASD based on multiple clinical rating scales and investigate their distinct Electroencephalogram (EEG) functional connectivity patterns. Eyes-opened resting-state EEG data were collected from 72 children with ASD and 63 typically developing (TD) children. A data-driven clustering approach based on Social Responsiveness Scales-Second Edition and Vinland-3 scores was used to identify subgroups. EEG functional connectivity and topological characteristics in four frequency bands were assessed. Two subgroups were identified: mild ASD (mASD, n = 37) and severe ASD (sASD, n = 35). Compared to TD, mASD showed increased functional connectivity in the beta band, while sASD exhibited decreased connectivity in the alpha band. Significant between-group differences in global and regional topological abnormalities were found in both alpha and beta bands. The proposed symptom-based clustering approach revealed the divergent functional connectivity patterns in the ASD subgroups that was not observed in typical ASD studies. Our study thus provides a new perspective to address the heterogeneity in ASD research.