Neural competition between concurrent speech production and other speech perception.

Area of Science:

• Neuroscience
• Auditory Perception
• Speech Processing

Background:

• Simultaneous speech production and comprehension present a neural competition within the auditory cortex (AC).
• Previous research suggested opposing signal dynamics for self and other speech processing, necessitating investigation into neural resolution mechanisms.

Purpose of the Study:

• To investigate neural competition during simultaneous self and other speech processing using human neuroimaging.
• To identify specific brain regions and lateralization patterns involved in resolving this competition.

Main Methods:

• Utilized neuroimaging (fMRI) in humans.
• Employed lateralized stimulations with external speech samples and ipsilateral/contralateral feedback of actively produced self-speech vowels.
• Conducted experiments with both simultaneous active self-speech and listening to recorded self-speech.

Main Results:

• Others' speech classification during active self-speech elicited activity in the planum temporale (PTe).
• Specific activation in the left anterior superior temporal cortex (STC) supported self-speech processing, while the right STC was more involved in other-speech processing during dichotic stimulation.
• Inferior frontal regions showed activity during recognition of recorded self-speech challenging other-speech classification, but not with active self-speech.

Conclusions:

• Active self-speech during other-speech perception induces a neural reordering, functional reassignment, and altered lateralization in auditory and frontal brain regions.
• Distinct mechanisms for self and other speech processing exist in the left and right STC, beyond general speech processing in PTe.
• Findings challenge established brain networks for uncompetitive speech perception, highlighting adaptive neural strategies during dual-task speech scenarios.