Why we hear a beat in music: linking auditory perception, prediction, and action

The question of why we hear a beat in music, particularly because we as humans are seemingly unique in this ability, has intrigued researchers for decades. In this talk, I will argue that studying our ability to tap to musical beat can reveal much about the neural underpinnings of auditory scene analysis, pattern detection, temporal prediction, and sensorimotor integration. I will present work that combines human and rodent behaviour, rodent electrophysiology, and computational modelling to show that rhythmic presentation of sounds may confer sensory salience, which could be explained by firing rate adaptation in the ascending auditory pathway. It is also known that rhythmic auditory stimulation recruits motor regions of the brain, and that striatal dopamine plays a key role in timekeeping, reward, and motor circuits. Therefore, a hypothesis could be that beat perception is the detection of an abstract temporal regularity that automatically engages motor circuits and on which temporal predictions can be formed, with additional reward attained when synchronising movements to future sensory events. An implication of this idea is that the ability to synchronise to an auditory beat, even if this is not a naturally rewarding behaviour, should be trainable in any species capable of precise timekeeping and anticipatory motor actions. I will present preliminary evidence that rats can indeed be trained to predictively synchronise to a metronome beat, potentially extending the range of tools and techniques available to study perception, prediction, and sensorimotor synchronisation in the brain.