Lateralization of ERPs to speech and handedness in the early development of Autism Spectrum Disorder

Abstract

BackgroundLanguage is a highly lateralized function, with typically developing individuals showing left hemispheric specialization. Individuals with autism spectrum disorder (ASD) often show reduced or reversed hemispheric lateralization in response to language. However, it is unclear when this difference emerges and whether or not it can serve as an early ASD biomarker. Additionally, atypical language lateralization is not specific to ASD as it is also seen more frequently in individuals with mixed- and left-handedness. Here, we examined early asymmetry patterns measured through neural responses to speech sounds at 12 months and behavioral observations of handedness at 36 months in children with and without ASD.MethodsThree different groups of children participated in the study: low-risk controls (LRC), high risk for ASD (HRA; infants with older sibling with ASD) without ASD, and HRA infants who later receive a diagnosis of ASD (ASD). Event-related potentials (ERPs) to speech sounds were recorded at 12 months. Utilizing a novel observational approach, handedness was measured by hand preference on a variety of behaviors at 36 months.ResultsAt 12 months, lateralization patterns of ERPs to speech stimuli differed across the groups with the ASD group showing reversed lateralization compared to the LRC group. At 36 months, factor analysis of behavioral observations of hand preferences indicated a one-factor model with medium to high factor loadings. A composite handedness score was derived; no group differences were observed. There was no association between lateralization to speech at 12 months and handedness at 36 months in the LRC and HRA groups. However, children with ASD did show an association such that infants with lateralization patterns more similar to the LRC group at 12 months were stronger right-handers at 36 months.ConclusionsThese results highlight early developmental patterns that might be specific to ASD, including a potential early biomarker of reversed lateralization to speech stimuli at 12 months, and a relation between behavioral and neural asymmetries. Future investigations of early asymmetry patterns, especially atypical hemispheric specialization, may be informative in the early identification of ASD.

EEG Analytics for Early Detection of Autism Spectrum Disorder: A data-driven approach

“…Finch et al . 61 found differences in lateralization patterns of ERPs to speech stimuli across the same groups as the present study by 12 months of age, with the ASD group showing reversed lateralization compared to the LRC− group 61 . Taken together, significant differences between ASD and non-ASD subjects may be present as early as 12 months or before in temporal, frontal and temporal-parietal regions.…”

Toward a conceptual framework for early brain and behavior development in autism

“…Differences in fine and gross motor skills observed at 6 months of age in HR-ASD children 7 suggest that motor development in the first year of life may have a role in the development of autism. 7 , 28 The presence of increased motor stereotypies in HR-ASD infants 14 at 12 months of age also points to abnormal development of motor systems, suggesting that processes that regulate diminishing gross motor rhythmic stereotypies between 6 and 12 months may be abnormal. Indeed sensorimotor systems that integrate and transform visual and auditory information into motor commands during the infant period play a prominent role in a recent computational model of ASD emergence.…”

“…Statistically significant main effects reported from group based analyses (with three or more groups) retain clinical meaning only after planned post hoc between-group analyses, controlling for family-wise error rate, have been described. For example, planned post hoc comparisons that reveal group differences between LR and HR-ASD groups (for example, oculomotor function; 26 fixation duration; 27 motor development; 7 ERP components 28 ) provide minimal interpretable information if the HR-negative group falls at an intermediary position and doesn’t statistically differ from either LR or HR-ASD groups. Indeed, there are very few studies that elucidate clear and interpretable evidence for a disorder-specific effect (that is, LR=HR-negative≠HR-ASD), a familial effect (that is, LR≠HR-negative=HR-ASD), or an endophenotypic effect (that is, LR≠HR-negative≠HR-ASD).…”

Language delay aggregates in toddler siblings of children with autism spectrum disorder

“…1 , differed from other studies in that it reported continuous language scores as estimated marginal means (rather than T -scores) based on a model testing effects of sex, age, language subscale, and diagnostic group on language outcome. This study shared subjects with some smaller studies containing appropriate continuous language data that were excluded from the main meta-analysis of continuous scores [ 45 , 67 , 68 ]. For purposes of comparison, supplemental analyses repeat the meta-analysis using these smaller studies instead of this large BSRC study and show consistent results (Additional file 1 : Table S1 and Figure S1).…”