Neural correlates of feedback processing during a sensory uncertain speech - nonspeech discrimination task

Area of Science:

• Cognitive Neuroscience
• Auditory Perception
• Speech Processing

Background:

• Understanding how the brain processes performance feedback, especially under conditions of uncertainty, is crucial for explaining decision-making and learning.
• Previous research has identified distinct neural components related to feedback processing, but their roles in the context of sensory uncertainty remain less clear.

Purpose of the Study:

• To investigate the neurocognitive mechanisms of feedback processing during a speech-nonspeech discrimination task with manipulated sensory uncertainty.
• To delineate the temporal sequence and functional roles of neural signals (anterior N1, Feedback-Related Negativity [FRN], P3) in response to feedback valence and uncertainty.

Main Methods:

• Participants performed a speech-nonspeech discrimination task using ambiguous German vowel stimuli.
• Sensory uncertainty was manipulated by creating stimuli that were morphs between speech and non-speech sounds.
• Electroencephalography (EEG) was used to record neural responses (anterior N1, FRN, P3) to performance feedback, alongside confidence ratings.

Main Results:

• The anterior N1 component, linked to attentional modulation, was largest following negative feedback, indicating early detection of behavioral relevance.
• Larger Feedback-Related Negativity (FRN) amplitudes were observed for both negative and uninformative feedback, suggesting a 'worse than expected' evaluation.
• Sensory uncertainty specifically modulated the feedback-P3 component, with larger amplitudes for high-uncertainty stimuli and positive feedback, indicating a more detailed analysis stage.

Conclusions:

• Feedback processing involves a sequential cascade: initial relevance detection (anterior N1), binary valence discrimination (FRN), and detailed analysis influenced by uncertainty (P3).
• Sensory uncertainty reduces objective accuracy in stimulus categorization but does not affect subjective response confidence.
• These findings provide a neurocognitive framework for understanding how uncertainty shapes feedback processing and influences perception.