Neural adaptation in brain responses to vocal and emotional sounds in school-age children

It is crucial to understand vocal emotion processing, as the ability to perceive and interpret emotional cues in speech plays a fundamental role in social and cognitive development. Child's brains adjust predictions about future sensory inputs, becoming increasingly efficient at interpreting and anticipating sensory input based on accumulated experience. Despite these key aspects of voice perception and the associated neurofunctional massive changes in the auditory cortex, little is known about neural adaptation to voice in school-age children. Neural adaptation was assessed in forty-one 8-13 years children and 27 adults. Auditory evoked potentials (AEPs) were measured in a roving paradigm while trains of 4, 8 and 14 repetitions of vocal (neutral and emotional) and non-vocal sounds were presented. Repetition Positivity (RP) was calculated as the difference between many (12-14) and (2-4) few repetitions. P1 amplitudes were measured to study regularity encoding dynamics according to repetitions. Obligatory AEPs do not display same morphology in both groups: P1-N250 is measured in children while P1-N1-P2 complex is described in adults. RP was measured in both groups in response to all sound categories. Repetition suppression was observed for P1 amplitude regardless of sound category. Our results indicate that regularity-encoding processes remain unaffected by the nature and valence of sounds highlighting an evolutionarily conserved mechanism. This stability suggests that the capacity to detect and adapt to regularities constitutes a fundamental property of the auditory system, enabling efficient filtering of redundant input and optimized allocation of neural resources to novel or behaviorally relevant stimuli.