Buildup and bistability in auditory streaming as an evidence accumulation process with saturation

Area of Science:

• Auditory perception
• Computational neuroscience
• Psychoacoustics

Background:

• Auditory stream formation, crucial for the cocktail party problem, is studied using ABA triplet sequences.
• Perception alternates between integration (galloping pattern) and segregation (interleaved streams).
• The buildup function (BUF) describes the increasing probability of segregation over time, influenced by frequency differences (DF).

Purpose of the Study:

• To develop and validate a pseudo-neuromechanistic model for auditory stream formation.
• To quantitatively account for perceptual alternations and buildup functions in auditory streaming.
• To investigate the role of auditory cortex activity in perceptual switching.

Main Methods:

• A pseudo-neuromechanistic model incorporating primary auditory cortex (A1) spiking activity was developed.
• The model simulates noisy evidence accumulation and threshold-based perceptual switching.
• The model was tested against experimental data on buildup functions, mean durations, and dominance distributions at various DFs.

Main Results:

• The model quantitatively predicts buildup functions, mean percept durations, and normalized dominance duration distributions across different DFs.
• It explains perceptual alternations without invoking direct competition between percepts.
• The model highlights the inadequacy of averaging independent triplet processing in previous studies.

Conclusions:

• The proposed model offers a straightforward and intuitive explanation for auditory stream segregation and integration dynamics.
• It accurately captures key features of perceptual switching in response to ABA tone sequences.
• The findings emphasize the importance of considering sequential processing and trial-to-trial variability in auditory perception models.