Bouncing the network: A dynamical systems model of auditory–vestibular interactions underlying infants’ perception of musical rhythm

• Published in: Developmental science 2021-09, Vol.24 (5), p.e13103-n/a
• Main Authors: Tichko, Parker, Kim, Ji Chul, Large, Edward W.
• Format: Article
• Language: English
• Subjects: Auditory plasticity; Auditory system; auditory–vestibular interactions; Hearing; Hebbian plasticity; infant development; Infants; Motor systems; music and movement; Neural networks; neural oscillations; nonlinear oscillators; Ontogeny; Perception; Rhythm; rhythm perception; Vestibular system
• ISSN: 1363-755X; 1467-7687
• DOI: 10.1111/desc.13103

Previous work suggests that auditory–vestibular interactions, which emerge during bodily movement to music, can influence the perception of musical rhythm. In a seminal study on the ontogeny of musical rhythm, Phillips‐Silver and Trainor (2005) found that bouncing infants to an unaccented rhythm influenced infants’ perceptual preferences for accented rhythms that matched the rate of bouncing. In the current study, we ask whether nascent, diffuse coupling between auditory and motor systems is sufficient to bootstrap short‐term Hebbian plasticity in the auditory system and explain infants’ preferences for accented rhythms thought to arise from auditory–vestibular interactions. First, we specify a nonlinear, dynamical system in which two oscillatory neural networks, representing developmentally nascent auditory and motor systems, interact through weak, non‐specific coupling. The auditory network was equipped with short‐term Hebbian plasticity, allowing the auditory network to tune its intrinsic resonant properties. Next, we simulate the effect of vestibular input (e.g., infant bouncing) on infants’ perceptual preferences for accented rhythms. We found that simultaneous auditory–vestibular training shaped the model's response to musical rhythm, enhancing vestibular‐related frequencies in auditory‐network activity. Moreover, simultaneous auditory–vestibular training, relative to auditory‐ or vestibular‐only training, facilitated short‐term auditory plasticity in the model, producing stronger oscillator connections in the auditory network. Finally, when tested on a musical rhythm, models which received simultaneous auditory–vestibular training, but not models that received auditory‐ or vestibular‐only training, resonated strongly at frequencies related to their “bouncing,” a finding qualitatively similar to infants’ preferences for accented rhythms that matched the rate of infant bouncing. Previous work suggests that auditory–vestibular interactions (e.g., bouncing infants to music) shape infants’ perception of musical rhythm in real‐time. Here, we introduce a dynamical systems model, based on neural oscillation and Hebbian plasticity, to model auditory–vestibular interactions underlying infants’ perception of musical rhythm. Similar to infants’ preferences for accented rhythms that matched the rate of bouncing, models trained on combined auditory–vestibular stimulation preferred vestibular‐related rhythmic frequencies, suggesting that plasticity in the auditory