Converging Notions on the Main Hypotheses Regarding the Origins of Beat Perception and Synchronization: The Key Role of Audiomotor Interactions

Abstract Beat perception and synchronization (BPS) describes a suite of cognitive and physical abilities that allow humans and some nonhuman animals to perceive and move to a rhythmic auditory stimulus. This chapter reviews two hypotheses that seek to explain the emergence of BPS in humans and a select few other animals (primarily nonhuman primates): the vocal learning hypothesis (VLH) and the gradual audiomotor evolution (GAE) hypothesis. VLH argues that vocal learning is a prerequisite to complex BPS, while GAE argues that BPS abilities may have been built upon extant interval timing mechanisms. Both hypotheses highlight the importance of sensorimotor networks in the brain, including dorsal pathways and basal-ganglia-thalamocortical loops, but they differ in the importance of vocal learning abilities in developing these pathways. Recent revisions to each hypothesis have been made to address an apparent continuum of BPS abilities across both vocal and nonvocal learning species. We suggest that there may be convergence between these revised hypotheses toward a more complete story of the emergence of rhythm production and perception.