Violation of auditory regularities is reflected in pupil dynamics

Area of Science:

• Neuroscience
• Cognitive Science
• Auditory Perception

Background:

• The brain constructs internal predictive models.
• Prediction violations can lead to model updates or replacements.
• Pupil dilation responses (PDRs) are linked to locus coeruleus-norepinephrine (LC-NE) activity and signal significant prediction errors.

Purpose of the Study:

• To investigate PDRs during transitions between regular and random auditory patterns.
• To explore how PDRs reflect internal model updates or resets.
• To examine PDRs as biomarkers for prediction violation magnitude.

Main Methods:

• Participants listened to auditory sequences with regular and random tone patterns.
• Participants were instructed to maintain attention by finding gaps.
• Pupil dilation responses (PDRs) were recorded and analyzed in relation to pattern transitions.

Main Results:

• Transitions from regular to random patterns induced PDRs, indicating model resets.
• Transitions between regular patterns also induced PDRs, suggesting model resets.
• Transitions from random to regular patterns did not induce PDRs, suggesting gradual model updates.
• PDRs and pupil event rates correlated with information content changes in auditory sequences.

Conclusions:

• PDRs serve as biomarkers for LC-NE activation, reflecting prediction violation extent.
• Auditory sequence transitions differentially impact internal models, signaled by PDRs.
• PDRs provide insights into neural mechanisms of predictive coding and model updating.