Flexible Representation of Speech

The overarching goal of this exploratory research is to understand the dynamic and flexible nature of speech processing in the human supratemporal plane. The temporal lobe has long been established as a region of interest in the speech perception and processing literature because it contains the auditory cortex. More recently, research has localized the supratemporal plane as an area that exhibits response specificity to acoustic properties of complex auditory signals like speech. The supratemporal plane, comprised of Heschl's gyrus, the planum polare, and the planum temporale, is capable of the rapid spectrotemporal analysis required to map acoustic information to linguistic representation. Neural activity in this area, however, is rarely studied directly because it is difficult to access with non-invasive measures like scalp electroencephalography (EEG). Capitalizing on the unique opportunity to access these areas via routine clinical stereoelectroencephalography (sEEG) in a patient population, this study seeks to understand how cortical responses reflect the diagnosticity of two acoustic-phonetic dimensions of interest and how responses rapidly and flexibly adapt to changes in listening demands. Examining how neural response to voice onset time (VOT) and fundamental frequency (F0) modulates as a function of perceptual weight carried in signaling phoneme categories, and identifying how changes in listening context shift perceptual weight, will provide invaluable data that indicates how speech processing flexibly adapts to short-term acoustic patterns.