The developmental trajectory of functional excitation‐inhibition balance relates to language abilities in autistic and allistic children

Abstract

Autism is a neurodevelopmental condition that has been related to an overall imbalance between the brain's excitatory (E) and inhibitory (I) systems. Such an EI imbalance can lead to structural and functional cortical deviances and thus alter information processing in the brain, ultimately giving rise to autism traits. However, the developmental trajectory of EI imbalances across childhood and adolescence has not been investigated yet. Therefore, its relationship to autism traits is not well understood. In the present study, we determined a functional measure of the EI balance (f‐EIB) from resting‐state electrophysiological recordings for a final sample of 92 autistic children from 6 to 17 years of age and 100 allistic (i.e., non‐autistic) children matched by age, sex, and nonverbal‐IQ. We related the developmental trajectory of f‐EIB to behavioral assessments of autism traits as well as language ability. Our results revealed differential EI trajectories for autistic compared to allistic children. Importantly, the developmental trajectory of f‐EIB values related to individual language ability. In particular, elevated excitability in late childhood and early adolescence was linked to decreased listening comprehension. Our findings provide evidence against a general EI imbalance in autistic children when correcting for non‐verbal IQ. Instead, we show that the developmental trajectory of EI balance shares variance with autism trait development at a specific age range. This is consistent with the proposal that the late development of inhibitory brain activity is a key substrate of autism traits.

Maturational constraints on tracking of temporal attention in infant language acquisition.

“…Indeed, autistic children show differential development in EEG oscillations and non-oscillatory electrophysiological activity (Tierney et al, 2012), and these electrophysiological differences relate to language development (Romeo et al, 2021;Shuffrey et al, 2022;Wilkinson et al, 2020). In a recent study, it has been shown that the development of E/I imbalances across childhood and adolescence are associated with individual differences in listening comprehension in both autistic and non-autistic children (Plueckebaum et al, 2023). Additionally, there are some indications that the maturation of iAPF is atypical in autistic children (Edgar et al, 2019;Green et al, 2022;but see Carter Leno et al, 2021;Lefebvre et al, 2018).…”