Functional characterization of human Heschl's gyrus in response to natural speech

• Published in: NeuroImage (Orlando, Fla.) Vol. 235; p. 118003
• Main Authors: Khalighinejad, Bahar, Patel, Prachi, Herrero, Jose L., Bickel, Stephan, Mehta, Ashesh D., Mesgarani, Nima
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15.07.2021; Elsevier Limited; Elsevier
• Subjects: Acoustics; Adult; Auditory Cortex - physiology; Auditory field maps; Brain Mapping; Cerebral hemispheres; Cortex (auditory); Cortex (temporal); Cortical mapping; EEG; Electrocorticography; Electrodes; Epilepsy - diagnosis; Epilepsy - surgery; Female; Functional morphology; Heschl’s gyrus; Human auditory cortex; Humans; iEEG; Information processing; Language; Latency; Male; Middle Aged; Neurosurgery; Neurosurgical Procedures; Sound; Spatial distribution; Speech; Speech perception; Speech Perception - physiology; Tonotopy; Heschl’s gyrus; Auditory field maps; Cortical mapping; iEEG; Tonotopy; Human auditory cortex
• ISSN: 1053-8119; 1095-9572; 1095-9572
• DOI: 10.1016/j.neuroimage.2021.118003

Heschl's gyrus (HG) is a brain area that includes the primary auditory cortex in humans. Due to the limitations in obtaining direct neural measurements from this region during naturalistic speech listening, the functional organization and the role of HG in speech perception remain uncertain. Here, we used intracranial EEG to directly record neural activity in HG in eight neurosurgical patients as they listened to continuous speech stories. We studied the spatial distribution of acoustic tuning and the organization of linguistic feature encoding. We found a main gradient of change from posteromedial to anterolateral parts of HG. We also observed a decrease in frequency and temporal modulation tuning and an increase in phonemic representation, speaker normalization, speech sensitivity, and response latency. We did not observe a difference between the two brain hemispheres. These findings reveal a functional role for HG in processing and transforming simple to complex acoustic features and inform neurophysiological models of speech processing in the human auditory cortex.