Socioeconomic status and neural processing of a go/no-go task in preschoolers: An assessment of the P3b.

While it is well established that lower socioeconomic status (SES) is associated with poorer executive functioning (EF), how SES relates to the neural processing of EF in childhood remains largely unexplored. We examined how household income and parent education related to amplitudes of the P3b, an event-related potential component, during one EF task. We assessed the P3b, indexing inhibition and attention allocation processes, given the importance of these skills for academic success. Children aged 4.5-5.5 years completed a go/no-task, which assesses inhibitory control and attention, while recording EEG. The P3b was assessed for both go trials (indexing sustained attention) and no-go trials (indexing inhibition processes). Higher household income was related to larger P3b amplitudes on both go and no-go trials. This was a highly educated sample, thus results indicate that P3b amplitudes are sensitive to household income even within the context of high parental education. Findings build on the behavioral literature and demonstrate that SES also has implications for the neural mechanisms underlying inhibition and attention processing in early childhood.

Neural responses to linguistic stimuli in children with and without autism spectrum disorder.

Atypical neural responses to language have been found in toddlers with autism spectrum disorder (ASD) and in their unaffected siblings. However, given that language difficulties are often seen in these children, it is difficult to interpret whether these neural differences are a result of the diagnosis of ASD or impairments in their language abilities. In this study, we recorded event-related potentials (ERPs) from four groups of 36-month-olds: low-risk control (LRC), high risk for ASD defined as having an older sibling with ASD (HRA) but who do not have ASD or milder autism-like symptoms (HRA-Typ), HRA children who do not have ASD but exhibit milder autism-like symptoms (HRA-Atyp) and HRA children diagnosed with ASD (ASD). Children listened to words expected to be acquired early (e.g. ball) and words expected to be acquired late (e.g. calf). ERPs were analysed over time windows sensitive to word processing as well as frontal and temporo-parietal sites over the left and right hemispheres. When controlling for language abilities, there were group differences within the temporo-parietal sites. Specifically, the HRA-Atyp group showed a different timed response to late words compared to the ASD and LRC groups. In addition, we found a relation between neural responses in the left frontal sites and ASD severity. Our results suggest that both language abilities and ASD diagnoses are important to consider when interpreting neural differences in lexical processing.

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

BACKGROUND: Language 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. METHODS: Three 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. RESULTS: At 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. CONCLUSIONS: These 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.