Language and Cognition

The auditory representation of speech sounds in human motor cortex

Connie Cheung
Liberty S. Hamilton
Keith Johnson
Edward F. Chang

In humans, listening to speech evokes neural responses in the motor cortex. This has been controversially interpreted as evidence that speech sounds are processed as articulatory gestures. However, it is unclear what information is actually encoded by such neural activity. We used high-density direct human cortical recordings while participants spoke and listened to speech sounds. Motor cortex neural patterns during listening were substantially different than during articulation of the same sounds. During listening, we observed neural activity in the superior and inferior regions of...

High-Resolution, Non-Invasive Imaging of Upper Vocal Tract Articulators Compatible with Human Brain Recordings

Kristofer E. Bouchard
David F. Conant
Gopala K. Anumanchipalli
Benjamin Dichter
Kris S. Chaisanguanthum
Keith Johnson
Edward F. Chang

A complete neurobiological understanding of speech motor control requires determination of the relationship between simultaneously recorded neural activity and the kinematics of the lips, jaw, tongue, and larynx. Many speech articulators are internal to the vocal tract, and therefore simultaneously tracking the kinematics of all articulators is nontrivial — especially in the context of human electrophysiology recordings. Here, we describe a noninvasive, multi-modal imaging system to monitor vocal tract kinematics, demonstrate this system in six speakers during production of nine American...

Phonological encoding and phonetic duration

Melinda D. Fricke

Co-advisors: Susanne Gahl and Keith Johnson