Little Listeners: Uncovering the Dynamics Between Predictive Processes and Conversation Turns During Early Language Acquisition

Background and Aims Despite language acquisition being a difficult undertaking, infants have various temporal sensitivities to sound that allows them to rapidly pick up speech. Conversational turn-taking is among the most important of these sensitivities, and previous literature emphasizes its anticipatory nature, citing predictive coding as a possible explanation. However, its mechanisms and development are still unknown. The present study aims to explore the development of anticipatory processes in infants during critical periods of language acquisition through conversational turn-taking. Methods 8 six-month-olds and 15 adults were presented with auditory stimuli in the form of conversations composed of a question and an answer, with varying pause lengths between conversational turns, while event-related potentials (ERPs) were recorded. Results Preliminary results showed infants experience greater neural activation in response to long conversational pauses. Adults instead show more activation during overlaps, with peaks of negative activity similar to the N400 in the right hemisphere. Infants also display the N400 during typical silences in the left hemisphere. Adults and infants show an inversion of polarity in the left hemisphere in conditions of typical and long pauses. Waveforms resembling the P1-N1-P2-N2 complex were found in adults and infants in the left hemisphere when exposed to long silences. Waveforms similar to MNM were also found in infants in response to typical pauses, and in adults during long pauses. Furthermore, infant left hemispheres show increased neural activity in response to long pauses, while adult left hemispheres show more activity when exposed to overlaps. Discussion The results, despite being preliminary, show promising signs that mechanisms for language processing are already in place at six months. Further data collection should confirm the preliminary results.