Effects of Repetition Suppression on Sound Induced Flash Illusion With Aging

Abstract

The sound-induced flash illusion (SiFI) is a classical auditory-dominated multisensory integration phenomenon in which the observer misperceives the number of visual flashes due to the simultaneous presentation of a different number of auditory beeps. Although the SiFI has been documented to correlate with perceptual sensitivity, to date there is no consensus as to how it corresponds to sensitivity with aging. The present study was based on the SiFI paradigm (Shams et al., 2000), adding repeated auditory stimuli prior to the appearance of audiovisual stimuli to investigate the effects of repetition suppression (RS) on the SiFI with aging. The repeated auditory stimuli consisted of one or two of the same auditory stimuli presented twice in succession, which were then followed by the audiovisual stimuli. By comparing the illusions in old and young adults, we aimed to explore the influence of aging on the RS of auditory stimuli on the SiFI. The results showed that both age groups showed SiFI effects, however, the RS performance of the two age groups had different effects on the fusion and fission illusions. The illusion effect in old adults was weaker than in young adults. Specifically, RS only affected fission illusions in the old adults but both fission and fusion illusions in young adults. Thus, the present study indicated that the decreased perceptual sensitivity based on auditory RS could weaken the SiFI effect in multisensory integration and that old adults are more susceptible to RS, showing that old adults perceived the SiFI effect weakly under auditory RS.

Repetition Suppression in Visual and Auditory Modalities Affects the Sound-Induced Flash Illusion

“…(2020) used repeated auditory stimuli to explore the SiFI and found that in young people, the hit rate with two preceding auditory stimuli was higher than that with one preceding auditory stimulus. This finding indicates that the RS effect also has an effect on information competition in audiovisual integration (Sun et al., 2020). However, it is still uncertain whether the RS effect in different modalities has different effects on audiovisual integration.…”

“…(2014) found striking differences between the fission and fusion illusions in older adults, indicating that the sensitivity and response bias associated with the SiFI were different in aging populations. Sun et al. (2020) also found, by comparing differences in the SiFI effect between older and younger adults, that the reason for the increase in fission illusion sensitivity caused by age was the decreased perceptual sensitivity among older adults.…”

“…Repetition suppression (RS) is an adaptation effect caused by stimulus repetition that can change individuals’ perceptual sensitivity (Kohn, 2007; Sun et al., 2020). That is, when exactly the same stimulus is repeated, the stimulus presented later will be affected by the stimulus presented first, thus causing neural activation induced by it to decline.…”

“…At the neural level, the amplitude of neural activity in the cerebral cortex induced by the stimuli decreased significantly after the stimuli were repeated (Grill-Spector et al., 1998; Malach et al., 1995). Previous studies have shown that repeated stimuli improve the visual system’s ability to process information, and the sensitivity of retinal or visual cortex neurons decreases after adaptation, suggesting that repeated stimuli can alter perceptual sensitivity (Kohn, 2007; Sun et al., 2020).…”

“…These results suggest that visual and auditory RS affect perceptual sensitivity. Sun et al. (2020) used repeated auditory stimuli to explore the SiFI and found that in young people, the hit rate with two preceding auditory stimuli was higher than that with one preceding auditory stimulus.…”