Neural responses in human superior temporal cortex support coding of voice representations.
Kyle Rupp1, Jasmine L Hect1, Madison Remick1
1Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America.
Plos Biology
|July 28, 2022
Summary
Human auditory cortex, including the superior temporal gyrus (STG) and superior temporal sulcus (STS), processes voice features automatically. Neural activity in STG/STS encodes voice category and acoustics, not just sound features, for effective voice perception.
Area of Science:
- Neuroscience
- Auditory Perception
- Human Audition
Background:
- Voice perception relies on specialized auditory cortex regions like the superior temporal gyrus (STG) and superior temporal sulcus (STS).
- The precise mechanisms of voice encoding within the human auditory cortex are not fully understood.
Purpose of the Study:
- To investigate voice encoding at the cortical level using intracerebral recordings.
- To determine how the auditory hierarchy contributes to voice perception.
Main Methods:
- Intracerebral recordings were obtained from 8 epilepsy surgery patients during auditory stimulus presentation.
- Analysis focused on voice selectivity and decoding of vocalizations from neural activity across the auditory hierarchy (STP, STG, STS).
Main Results:
- Voice selectivity increased along the auditory hierarchy from the supratemporal plane (STP) to the STG and STS.
- Vocalizations were accurately decoded from auditory cortical activity, even without linguistic content.
- STG/STS responses were best explained by voice category and acoustics, unlike STP responses, which were explained by acoustic features alone.
Conclusions:
- Neural activity in the STG and STS exhibits an early, less-selective window followed by a sustained, voice-selective window.
- The auditory cortex, particularly STG/STS, employs categorical encoding for voice perception, facilitating feature extraction beyond basic acoustic properties.
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