Electroencephalographic correlates of word and non-word listening in children with specific language impairment: An observational study

Auditory processing in children diagnosed with speech and language impairment (SLI) is atypical and characterized by reduced brain activation compared to typically developing (TD) children. In typical speech and language development processes, frontal, temporal, and posterior regions are engaged during single-word listening, while for non-word listening, it is highly unlikely that perceiving or speaking them is not followed by frequent neurones’ activation enough to form stable network connections. This study aimed to investigate the electrophysiological cortical activity of alpha rhythm while listening words and non-words in children with SLI compared to TD children. The participants were 50 children with SLI, aged 4 to 6, and 50 age-related TD children. Groups were divided into 2 subgroups: first subgroup – children aged 4.0 to 5.0 years old (E = 25, C = 25) and second subgroup – children aged 5.0 to 6.0 years old (E = 25, C = 25). The younger children’s group did not show statistically significant differences in alpha spectral power in word or non-word listening. In contrast, in the older age group for word and non-word listening, differences were present in the prefrontal, temporal, and parieto-occipital regions bilaterally. Children with SLI showed a certain lack of alpha desynchronization in word and non-word listening compared with TD children. Non-word perception arouses more brain regions because of the unknown presence of the word stimuli. The lack of adequate alpha desynchronization is consistent with established difficulties in lexical and phonological processing at the behavioral level in children with SLI.