Our MTS speaker for Monday April 14 is John Iversen from UC San Diego.

April 14th, 3pm, KL 232

Title: Rhythm and the Brain: Studies of neural dynamics of beat perception.

Abstract: I am interested in using music as a tool to understand fundamental brain processes, such as how our perceptions of the world are jointly shaped by external stimuli and internal interpretation. In this talk I’d like to present an overview of several studies that have examined different aspects of rhythm perception and production, including the impact of culture on rhythm perception, comparative studies of rhythm production, the role of modality on rhythm perception, and the neurobiology of rhythm perception. Rhythm provides a rich domain for studying the interaction of auditory and motor systems, and my focus is on the potential impact of the motor system on auditory perception. The perceptual experience of a simple musical rhythm, for example, strongly depends upon the listener’s metrical interpretation (where one hears the beat). Such interpretation can be altered at will, providing a model of the voluntary cognitive organization of perception. We would like to understand the mechanisms involved in generating the internal sense of beat. Where in the brain do the bottom-up and top-down influences in rhythm perception converge? Is it purely auditory, or does it involve other systems, such as motor system? To answer these questions we have conduced a series of experiments in which we measured brain responses as participants listened to a repeating rhythmic phrase, using magnetoencephalography. Because of the volitional nature of beat perception, participants were able to voluntarily shape their rhythm perception, even as the physical stimulus was unchanged. I will review several results demonstrating temporally precise rhythmic modulation of beta-band (20-30Hz) oscillatory responses that reflect the active interpretation of a rhythm, and results localizing the endogenous beat to motor cortices. I hope this can lead to a vigorous discussion of theories of temporal perception.

Bio: John Iversen is a cognitive neuroscientist studying music and the brain. He is currently an Associate Project Scientist at UC San Diego in the Institute for Neural Computation. After undergraduate studies in Physics at Harvard, John received graduate degrees in Philosophy of Science and in Speech at Cambridge, and received a PhD in Speech and Hearing Science from MIT. After a decade at The Neurosciences Institute in La Jolla, he is currently at UCSD at the Swartz Center for Computational Neuroscience. His work has focused on the study of rhythm perception and production in music and language, spanning behavioral and neuroscience approaches. His work has addressed the role of culture in rhythm perception, whether rhythm perception is specially tied to the auditory sense, and brain mechanisms involved in generating the perceived beat in music. Increasingly he is directing this work towards applications to medicine and education. He is currently directing the SIMPHONY project at UCSD, a longitudinal study of the effect of music training on children’s brain and cognitive development. Woven through this work is a desire to understand how we actively shape our perceptions of the world. John draws from a background in physics and neuroscience and a life-long interest in percussion, which currently finds expression through Japanese taiko drum performance with San Diego Taiko, a group that he co-founded in 2004.