Watch me talk, and learn: Characterizing the development of neural mechanisms underlying the co-learning of speech perception and production – PER2PROD

Learning to speak, from simple babbling to pronouncing complex sentences, requires learning to combine articulatory movements with abstract linguistic knowledge. This learning is shaped by the mutual constraints that the perception and production systems exert on each other, but a biophysical description of the mechanisms by which this interaction develops is lacking. My research program seeks to identify the neural mechanisms responsible for the interaction between perception and production systems by exploiting the fundamental characteristics of the temporal dynamics of speech. I hypothesize that learning to speak is an incremental learning process, in which the temporal dynamics of articulatory movements progressively influence the temporal dynamics of audiovisual integration of speech, and vice versa. I argue that neural oscillations, as an emergent property of the collective and synchronized activity of neurons commonly engaged in a task, are the computational principle underlying the learning transfer between perception and production. Using a combination of behavioural testing and neural recordings, I will test this hypothesis by first probing whether knowledge of articulatory movement is necessary for audiovisual perception to emerge in infants aged 3-21 months. Second, I will identify whether the ability to follow the rhythm of perceived speech modulates the capacity of 15-27 months old to produce words. Third, I will assess the concomitant improvement of production and perception skills (i) by characterizing the patterns of developmental change of the coherence between the audiovisual integrative cortical areas and the articulatory motor system, and (ii) by testing this model on two complementary pathologies that have an impact either on the production or perception system. The proposed research will shed light on a hitherto neglected learning process, yet known to shape our social success, and identify its associated neural mechanisms.