White Matter Fiber Bundles Bridging Music and Movement

Abstract

Humans naturally move in time with music, whereas similar behavior is rarely observed in other animals. This ability arises from beat perception and synchronization (BPS), the coupled processes of perceiving a musical beat and aligning movements to it. This article examines the neural basis of BPS by focusing on connections between auditory and motor systems. First, I review theoretical frameworks that explain BPS in evolutionary background and neural mechanisms: the Vocal Learning and Rhythmic Synchronization hypothesis, which emphasize auditory–motor circuits supporting complex vocal learning, and the Gradual Audiomotor Evolution hypothesis, which highlights gradual refinements of the motor cortico–basal ganglia–thalamo–cortical loop and the dorsal auditory pathway. Although they differ in emphasis, both frameworks underscore the importance of the dorsal auditory pathway that links auditory and motor systems. I then summarize anatomical evidence on two white-matter pathways along this dorsal pathway—“direct”(long-segment arcuate fasciculus) and “indirect” (posterior arcuate fasciculus and superior longitudinal fasciculus) pathways. These pathways may play complementary roles in BPS, and clarifying this functional division of labor is a challenge for future research. This line of work may ultimately illuminate why humans are uniquely driven to move with musical rhythm.