(PS4-50) Infant EEG and Expressive Language Are Associated with Executive Function

One of the earliest indicators of autism spectrum disorder (ASD), a neurodevelopmental disorder, is a delay in language and communication development, especially expressive language (Buzhardt et al., 2022). Expressive language is the use of language to interact with the world (Balboni et al., 2016). Along with impairments in social communication, research has indicated that individuals with ASD also have impairments in executive functioning (EF), especially in inhibition, working memory, and cognitive flexibility (Corbett et al., 2009; Solomon et al., 2008). Both of these impairments can be explained in part due to differences in brain activity for individuals with ASD. Research using electroencephalography (EEG) has shown that children with ASD show reduced alpha band power across many brain regions including the frontal cortex (Wang et al., 2013), which is involved in EF and social skills (Otero & Barker, 2013). Such early neural biomarkers of ASD are important for understanding the development of this disorder. The goal of the current study was to examine neural and language predictors of EF in infants.

Thirty-one infants aged (9-12 months old) were recruited for this study. Infants completed the A-not-B task. The A-not-B task measures early EF: cognitive flexibility, inhibition, and working memory (Schworer et al., 2022). Participants’ adaptive behavior was measured by parent report using the Vineland Adaptive Behavior Scales-Second Edition (Vineland-II), including communication. This study focused specifically on the expressive communication subdomain of communication. Baseline EEG was collected while participants watched an age-appropriate video. Analysis used participants’ performance on the A-not-B task, scores from the expressive communication subdomain from the Vineland-II, and baseline alpha power in frontal electrodes 3 and 4. A linear regression showed the overall model was significant (R_­² = .62, p = .019) and that unique variance could be attributed to both F3 electrode alpha power (β = 1.97, p = .018) and expressive communication (β = .60, p = .011).

            These results indicate that infants’ expressive communication predicts their performance on the A-not-B task. Results also indicated that baseline alpha power at the F3 electrode predicted A-not-B task performance above and beyond power at F4. The F3 electrode is located on the left side of the scalp which would indicate that left frontal lobe activity influences A-not-B task performance. This suggests that the left prefrontal cortex (PFC) is specifically related to EF in infancy and may relate to lateralization of working memory to the left PFC (Best & Miller, 2010). These findings indicate the importance of further research regarding the neural mechanisms behind EF as frontal lateralization develops. It is also important to understand the neural mechanisms behind lateralization development in the frontal lobe in in infants who are well below the typical age of ASD diagnosis and may help distinguish the differences in neural etiology and lateralization that  underlie the symptomology.