The neurophysiological correlates of click rate discrimination in children

The current study investigated rhythmic stimuli perception in typically developing children (5-18 years old, n = 48, 22 girls). In the behavioral part of the study, where children discriminated between two click trains varied around frequencies of 16, 27, 40 and 83 Hz, we identified the shift toward better performance for the frequencies higher than 40 Hz. To dig into neurophysiological mechanisms of this process we recorded 28-channels EEG while similar auditory clicks were presented in trains of 500 ms with interstimulus intervals of 800-1000 ms. We focused on brain correlates of temporal and pitch-related processing - the intertrial-phase coherence at the frequency of stimulation (ITPC) and sustained wave (SW). ITPC was more pronounced under the stimulation at frequencies of 27 and 40 Hz and served as a reliable predictor of click rate discrimination at 27 Hz. Conversely, the SW exhibited a larger amplitude under the stimulation at 40 and 83 Hz and explained the variance in click rate discrimination at 40 Hz, with higher SW amplitude correlating with better performance. Our results elucidate the association of ITPC and SW with specific aspects of auditory perception in children, which might help to understand abnormalities in these responses seen in neurodevelopmental disorders.