Sam Tilsen

Postdoctoral Fellow

Hearing and Communication Neuroscience

University of Southern California

[CV]

      Hierarchy and recursion are fundamental concepts in the scientific study of language. My research aims to understand why we observe hierarchical and recursive structures by investigating speech behavior and the neural processes from which linguistic patterns emerge. Two areas I focus on are (1) how articulatory, rhythmic, and prosodic systems interact, and (2) the role of inhibitory control in speech. Currently I am using magnetoencephalography to identify neural correlates of speech rhythmicity, and I am using magnetometry to understand how syllable stress interacts with inhibitory control of articulatory gestures. My theoretical approach attempts to unify the understanding of diverse prosodic and articulatory phenomena using a dynamical systems framework in which planning processes are described by interacting waves. My work is informed by research in neurolinguistics and systems neuroscience. I use concepts such as synchronization, stability, coupling, relative phase, potential functions, phase transitions, stochastic forces, etc. to assist in geometric visualization of the cognitive processes which give rise to recursive patterns and hierarchical structure.