The developmental trajectory of vocal and event-related potential responses to frequency-altered auditory feedback.

Speech motor control develops gradually as the acoustics of speech are mapped onto the positions and movements of the articulators. In this event-related potential (ERP) study, children and adults aged 4-30 years produced vocalizations while exposed to frequency-altered feedback. Vocal pitch variability and the latency of vocal responses were found to differ as a function of age. ERP responses indexed by the P1-N1-P2 complex were also modulated as a function of age. P1 amplitudes decreased with age, whereas N1 and P2 amplitudes increased with age. In addition, a correlation between vocal variability and N1 amplitudes was found, suggesting a complex interaction between behavioural and neurological responses to frequency-altered feedback. These results suggest that the neural systems that integrate auditory feedback during vocal motor control undergo robust changes with age and physiological development.