Never mind the repeat: How speech expectations reduce tracking at the cocktail party

Area of Science:

• Auditory Neuroscience
• Cognitive Neuroscience
• Speech Processing

Background:

• The brain selectively processes speech in noisy environments by leveraging past experiences.
• Understanding how prior experience alters neural processing of speech mixtures is crucial for auditory perception research.

Purpose of the Study:

• To investigate changes in selective neural processing of speech mixtures due to listener experience.
• To examine how attention interacts with different types of speech priming (exact, voice, message) on cortical responses.

Main Methods:

• Utilized three priming experiments to quantify cortical selection of temporal speech landmarks.
• Applied the temporal response function (TRF) method to single-trial electroencephalography (EEG) recordings.
• Analyzed attentional effects on speech processing based on target and background speaker priming.

Main Results:

• Prior experience led to attenuations in cortical responses during multispeaker listening, counteracting typical attentional gains.
• Observed significant changes at the P2 processing stage (220-320 msec) specifically for primed speech targets.
• No suppressions were found at earlier processing stages or under partial priming conditions.

Conclusions:

• Late-stage selective attention involves the auditory system testing its predictive model of speech.
• A reduction in the P2 component correlates with improved target word recall, suggesting its role in temporal prediction error detection.
• The auditory system refines temporal structure inference for continuous speech representation based on predictive models.