Predicting the sound-induced flash illusion: A time-window-of-integration approach

The sound-induced flash illusion (SIFI) refers to the observation that pairing a single flash with two auditory beeps leads to the illusory perception of two visual stimuli (fission illusion). Susceptibility to the illusion depends on many factors, like exact physical stimulus parameters, participants' expectations, attention, age, and clinical/nonclinical population membership. While there exist many experimental studies, very few models have been proposed to account for the phenomenon. Here we suggest a formal model called "time-window-of-integration for SIFI" based on the notion of a temporal binding window that predicts the occurrence of illusory flashes as a function of the temporal and physical stimulus arrangement. The model's performance is illustrated in a study investigating differences in SIFI performance between elderly hearing aid users and those with the same degree of mild hearing loss who were not using hearing aids. The results suggest that the higher incidence of reporting an illusory flash for hearing aid users is due to both a larger temporal window of integration and a larger bias to report the illusion. By proposing a time window mechanism for the effects of stimulus parameter variations on the illusion, thereby complementing the Bayesian causal inference explanation for the cognitive foundations of the illusion, the time-window-of-integration for SIFI model will help to better understand the diverse results from clinical and nonclinical studies. (PsycInfo Database Record (c) 2026 APA, all rights reserved).