Reduced Neural Specialization for Word-level Linguistic Prosody in Children with Autism

A thematic review of autism spectrum disorder research in Saudi Arabia: Insights into diagnosis, assessment, and language considerations

This study reviews the crucial role of language in Autism Spectrum Disorder (ASD) diagnosis and assessment in Saudi Arabia. Using tailored search strings, 206 relevant documents were retrieved from the Web of Science and Scopus databases. An increasing trend in ASD research in Saudi Arabia was observed through temporal analysis. Keyword analysis identified key themes including "autism," "language," "assessment," "diagnosis," "Saudi Arabia," and "children." The focus of research has shifted over the years, from pure clinical and diagnostic aspects to a more comprehensive approach that includes language and cultural factors in ASD evaluation. The findings underscore the need for culturally and linguistically sensitive assessment tools, acknowledging the impact of bilingualism on language development, and the importance of language difficulties in diagnostic decision-making. The study highlights the necessity for further research, especially longitudinal studies examining the influence of language and cultural factors on ASD outcomes. The findings are significant for clinical practice, emphasizing the need for linguistically sensitive approaches in ASD diagnosis and assessment. This research serves as a guide for future studies by identifying the gaps in existing literature and areas of focus. The study identifies crucial gaps in existing literature, particularly the need for longitudinal studies examining the influence of language and cultural factors on ASD outcomes. The findings underscore the importance of culturally and linguistically sensitive approaches in ASD diagnosis and assessment, providing a novel insight for future research and clinical practice in Saudi Arabia.

The Neural Development of Chinese Lexical Tone Perception: A Mismatch Negativity Study Across Childhood, Adolescence, and Adulthood

BACKGROUND/OBJECTIVES

In a tonal language like Chinese, phonologically contrasting tones signify word meanings at the syllable level. Although the development of lexical tone perception ability has been examined in many behavioral studies, its developmental trajectory from childhood to adulthood at the neural level remains unclear. This cross-sectional study aimed to examine the issue by measuring the mismatch negativity (MMN) response to a Chinese lexical tonal contrast in three groups.

METHODS

The MMN response to a flat-falling tonal contrast (Tone1 versus Tone4) were recorded from children (25 participants aged 6-8), adolescents (26 participants aged 12-14), and young adults (20 participants aged 18-24). Nonsense speech stimuli were also used by superimposing Tone1 and Tone4 on an English syllable.

RESULTS

All three groups demonstrated typical early MMN responses in both the meaningful and nonsense syllable conditions. However, the MMN amplitudes varied significantly across groups, with the child group showing smaller responses compared to the adolescent and adult groups, while the latter two groups had similar MMN amplitudes.

CONCLUSIONS

Neural sensitivity to tonal contrasts is not fully mature in children and reaches a more adult-like level during adolescence, with no significant difference in sensitivity to meaningful versus nonsense syllables. These results provide new insights into the neural development of lexical tone perception in a tonal language, highlighting its maturation during adolescence in this process.

Focus-marking in a tonal language: Prosodic differences between Cantonese-speaking children with and without autism spectrum disorder

Abnormal speech prosody has been widely reported in individuals with autism. Many studies on children and adults with autism spectrum disorder speaking a non-tonal language showed deficits in using prosodic cues to mark focus. However, focus marking by autistic children speaking a tonal language is rarely examined. Cantonese-speaking children may face additional difficulties because tonal languages require them to use prosodic cues to achieve multiple functions simultaneously such as lexical contrasting and focus marking. This study bridges this research gap by acoustically evaluating the use of Cantonese speech prosody to mark information structure by Cantonese-speaking children with and without autism spectrum disorder. We designed speech production tasks to elicit natural broad and narrow focus production among these children in sentences with different tone combinations. Acoustic correlates of prosodic focus marking like f0, duration and intensity of each syllable were analyzed to examine the effect of participant group, focus condition and lexical tones. Our results showed differences in focus marking patterns between Cantonese-speaking children with and without autism spectrum disorder. The autistic children not only showed insufficient on-focus expansion in terms of f0 range and duration when marking focus, but also produced less distinctive tone shapes in general. There was no evidence that the prosodic complexity (i.e. sentences with single tones or combinations of tones) significantly affected focus marking in these autistic children and their typically-developing (TD) peers.

Auditory Challenges and Listening Effort in School-Age Children With Autism: Insights From Pupillary Dynamics During Speech-in-Noise Perception

PURPOSE

This study aimed to investigate challenges in speech-in-noise (SiN) processing faced by school-age children with autism spectrum conditions (ASCs) and their impact on listening effort.

METHOD

Participants, including 23 Mandarin-speaking children with ASCs and 19 age-matched neurotypical (NT) peers, underwent sentence recognition tests in both quiet and noisy conditions, with a speech-shaped steady-state noise masker presented at 0-dB signal-to-noise ratio in the noisy condition. Recognition accuracy rates and task-evoked pupil responses were compared to assess behavioral performance and listening effort during auditory tasks.

RESULTS

No main effect of group was found on accuracy rates. Instead, significant effects emerged for autistic trait scores, listening conditions, and their interaction, indicating that higher trait scores were associated with poorer performance in noise. Pupillometric data revealed significantly larger and earlier peak dilations, along with more varied pupillary dynamics in the ASC group relative to the NT group, especially under noisy conditions. Importantly, the ASC group's peak dilation in quiet mirrored that of the NT group in noise. However, the ASC group consistently exhibited reduced mean dilations than the NT group.

CONCLUSIONS

Pupillary responses suggest a different resource allocation pattern in ASCs: An initial sharper and larger dilation may signal an intense, narrowed resource allocation, likely linked to heightened arousal, engagement, and cognitive load, whereas a subsequent faster tail-off may indicate a greater decrease in resource availability and engagement, or a quicker release of arousal and cognitive load. The presence of noise further accentuates this pattern. This highlights the unique SiN processing challenges children with ASCs may face, underscoring the importance of a nuanced, individual-centric approach for interventions and support.

Atypical brain lateralization for speech processing at the sublexical level in autistic children revealed by fNIRS

Autistic children often exhibit atypical brain lateralization of language processing, but it is unclear what aspects of language contribute to this phenomenon. This study employed functional near-infrared spectroscopy to measure hemispheric lateralization by estimating hemodynamic responses associated with processing linguistic and non-linguistic auditory stimuli. The study involved a group of autistic children (N = 20, mean age = 5.8 years) and a comparison group of nonautistic peers (N = 20, mean age = 6.5 years). The children were presented with stimuli with systematically decreasing linguistic relevance: naturalistic native speech, meaningless native speech with scrambled word order, nonnative speech, and music. The results revealed that both groups showed left lateralization in the temporal lobe when listening to naturalistic native speech. However, the distinction emerged between autism and nonautistic in terms of processing the linguistic hierarchy. Specifically, the nonautistic comparison group demonstrated a systematic reduction in left lateralization as linguistic relevance decreased. In contrast, the autism group displayed no such pattern and showed no lateralization when listening to scrambled native speech accompanied by enhanced response in the right hemisphere. These results provide evidence of atypical neural specialization for spoken language in preschool- and school-age autistic children and shed new light on the underlying linguistic correlates contributing to such atypicality at the sublexical level.

Neurophysiological measures of auditory sensory processing are associated with adaptive behavior in children with Autism Spectrum Disorder

BACKGROUND

Atypical auditory cortical processing is consistently found in scalp electrophysiological and magnetoencephalographic studies of Autism Spectrum Disorder (ASD), and may provide a marker of neuropathological brain development. However, the relationship between atypical cortical processing of auditory information and adaptive behavior in ASD is not yet well understood.

METHODS

We sought to test the hypothesis that early (100-175 ms) auditory processing in ASD is related to everyday adaptive behavior through the examination of auditory event-related potentials (AEPs) in response to simple tones and Vineland Adaptive Behavior Scales in a large cohort of children with ASD (N = 84), aged 6-17, and in age- and IQ- matched neurotypically (NT) developing controls (N = 132).

RESULTS

Statistical analyses revealed significant group differences in early AEPs over temporal scalp regions (150-175 ms), and the expected rightward lateralization of the AEP (100-125 ms and 150-175 ms) to tonal stimuli in both groups. Lateralization of the AEP (150-175 ms) was significantly associated with adaptive functioning in the socialization domain.

CONCLUSIONS

These results lend support to the hypothesis that atypical processing of sensory information is related to everyday adaptive behavior in autism.