Reactivity of the EEG μ Rhythm on Observing and Performing Actions in Young Children with Different Levels of Receptive Speech Development

Abstract

The reactivity of EEG power in the individually defined μ frequency ranges was studied in the central, frontal, and parietal EEG leads in children imagining an action, watching the real action, and performing the action him- or herself. The study involved 39 children aged 17–41 months. Analysis of the variance of EEG power in the μ range demonstrated significant desynchronization in the central, frontal, and parietal EEG leads on observation and performance of actions. The Observing a real action situation was accompanied by greater power desynchronization in the μ range in the medial frontal (Fz) and medial parietal (Pz) loci as compared with the Observing a fake action situation. With the aim of identifying the role of the mirror neuron system in speech assimilation processes, we analyzed the characteristics of EEG μ rhythm reactivity in children with different levels of receptive speech development, as defined using the Bayley test. Children with high levels on the receptive speech scale were found to display greater EEG power desynchronization in the μ range when observing a real action in the frontal (F3) and parietal (P3) loci of the left hemisphere as compared with children with intermediate levels on this scale. The results obtained here show that children demonstrating higher levels of activation of the mirror neuron system have higher levels of speech comprehension.