Functional organization of the superior temporal gyrus for speech perception

PROJECT SUMMARY The basic mechanisms underlying comprehension of spoken language are still largely unknown. Over the past decade, we have gained new insights to how the human brain extracts the most fundamental linguistic elements (consonants and vowels) from a complex and highly variable acoustic signal. However, the next set of questions await pertaining to the sequencing of those auditory elements and how they are integrated with other features, such as, the amplitude envelope of speech. Further investigation of the cortical representation of speech sounds can likely shed light on these fundamental questions. Previous research has implicated the superior temporal cortex in the processing of speech sounds, but little is known about how these sounds are linked together into the perceptual experience of words and continuous speech. The recording of neural activity directly from the cortical surface is a promising approach to study this since it can provide both high spatial and temporal resolution. This proposal seeks to examine the mechanisms of phonetic encoding by utilizing neurophysiological recordings obtained during neurosurgical procedures. High-density electrode arrays and advanced signal processing will be utilized to unravel both local and population encoding of speech sounds in the lateral temporal cortex. The overall goal is to determine how the brain extracts linguistic elements from a complex acoustic speech signal towards better understanding and remediating human language disorders.