Feindel Brain and Mind Seminar Series - September 30

Research Director, Aix Marseille Université, INSERM, INS, Institut de Neurosciences des Systèmes, Marseille, France

Neural Dynamics and Computations Constraining Speech and Music Processing

Abstract: Benjamin Morillon will depict the neural dynamics underlying music perception and speech comprehension, emphasizing time scales and adaptive processes. First, he will explore why humans spontaneously dance to music, presenting behavioral and neuroimaging evidence that motor dynamics reflect predictive timing during music listening. While auditory regions track the rhythm of melodies, intrinsic neural dynamics at delta (1.4 Hz) and beta (20-30 Hz) frequencies in the dorsal auditory pathways encode the wanting-to-move experience, or "groove." These neural dynamics are organized along the pathway in a spectral gradient, with the left sensorimotor cortex coordinating groove-related delta and beta activity. Predictions from a neurodynamic model suggest that spontaneous motor engagement during music listening arises from predictive timing, driven by interactions of neural dynamics along the dorsal auditory pathway. Second, to investigate speech comprehension, a framework was developed utilizing the concept of channel capacity. This approach examines the influence of various acoustic and linguistic features on the comprehension of compressed speech. Results demonstrate that comprehension is independently affected by each feature, with varying degrees of impact and a clear dominance of the syllabic rate. Complementing this framework, human intracranial recordings reveal how neural dynamics in the auditory cortex adapt to different acoustic features, facilitating parallel processing of speech at syllabic and phonemic time scales. These findings underscore the dynamic adaptation of neural processes to temporal characteristics in speech and music, enhancing our understanding of language and music perception.

Bio: Benjamin Morillon is a cognitive neuroscientist specializing in human auditory neurophysiology and the sequential encoding of information in the human brain. After earning a PhD at the Ecole Normale Supérieure de Paris (France), he worked as a postdoctoral fellow at Columbia University (USA) and McGill University (Canada). Since 2016, he has held a tenured position at the Institut de Neurosciences des Systèmes in Marseille, France. He advocates for a synergetic approach that integrates computational modeling, cognitive psychology, and multi-modal functional neuroimaging to understand how humans process sensory information. His research primarily addresses two key questions. The first line of inquiry focuses on auditory hemispheric asymmetry, particularly during speech and music perception, to uncover the physiological and functional similarities and differences between the two auditory cortices. This research aims to elucidate the fundamental relationship between acoustic properties and specific neural networks, revealing how these interactions facilitate efficient auditory neural coding. The second research focus examines the interplay between auditory and motor neural systems. This involves analyzing how overt motor routines and covert motor cortical activity influence auditory processing and behavioral performance, as well as identifying which auditory stimuli, such as groovy music, automatically evoke a motor neural response. Overall, his work underscores the critical role of motor areas in sensory perception, particularly in the processing of contextual temporal information.

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