No abstract

Keywords N400, EEG, language comprehension, sensitivity, Emotiv EPOC+, multivariate pattern analyses Highlights -New methods show hints that brain data can be used to infer language processing -A gaming headset records EEG waveforms comparable to a research grade system -50% of individual children show significant N400 effects in two paradigms -We can decode semantic context in up to 88% of children using multivariate analyses Abstract:Can we use electrophysiological data to assess language processing? Although we usually cannot infer cognition from brain data, there are some circumstances in which discriminative brain signals are enough to tell us that cognitive processing has occurred. For example, if we observe differential neural responses to identical stimuli that vary only in cognitive context, we can infer an influence of context on stimulus processing. Here, we used this logic to develop a test for receptive language ability in individual children. We were motivated by the suggestion that some non-verbal individuals, such as a subset of autistic children, may understand more language than they can demonstrate; for these people a neural test would be transformative. We developed two child-friendly paradigms in which typically developing children listened to identical spoken words in congruent and incongruent lexicalsemantic contexts. In the congruent condition, the target word was strongly predicted by the context, while in the incongruent condition, the target word violated lexical-semantic predictions. In both paradigms, we simultaneously measured EEG with a research-grade system, Neuroscan's SynAmps2, and an adapted gaming system, Emotiv's EPOC+. In both paradigms, at a group level, we found a statistically significant N400 effect to lexical-semantic violations, and we also detected significant effects in about half of our participants individually.The same effects were present, although with a numerically smaller amplitude, with EPOC+.Using multivariate analyses on individual children's EEG data increased our sensitivity to detect evidence of lexical-semantic processing, reaching an 88% detection rate in a paradigm using sentences. This provides a promising avenue to assess language comprehension in individuals, which could be used to identify language comprehension abilities in children who may otherwise struggle to demonstrate how much they understand.

It has been proposed that language impairments in children with Autism Spectrum Disorders (ASD) stem from atypical neural processing of speech and/or nonspeech sounds. However, the strength of this proposal is compromised by the unreliable outcomes of previous studies of speech and nonspeech processing in ASD. The aim of this study was to determine whether there was an association between poor spoken language and atypical event-related field (ERF) responses to speech and nonspeech sounds in children with ASD (n = 14) and controls (n = 18). Data from this developmental population (ages 6-14) were analysed using a novel combination of methods to maximize the reliability of our findings while taking into consideration the heterogeneity of the ASD population. The results showed that poor spoken language scores were associated with atypical left hemisphere brain responses (200 to 400 ms) to both speech and nonspeech in the ASD group. These data support the idea that some children with ASD may have an immature auditory cortex that affects their ability to process both speech and nonspeech sounds. Their poor speech processing may impair their ability to process the speech of other people, and hence reduce their ability to learn the phonology, syntax, and semantics of their native language.