Brief incoherent audiovisual contexts reduce the McGurk effect by decreasing visual weight.

Evidence

To provide evidence for this “binding and fusion” AVSSA process, Nahorna et al. ( 2012 , 2015 ) showed that the McGurk effect can be significantly and strongly reduced by an audiovisual context made of a few seconds of incoherent material (sounds and images coming from different speech sources) presented before the McGurk target (audio “ba” plus video “ga”): the target, classically perceived as “da” in the McGurk effect, was more often perceived as “ba”, suggesting a decreased weight of the visual input in the fusion process. The interpretation was that the incoherent context resulted in an “unbinding” effect decreasing the visual weight and hence diminishing the McGurk effect. — Dijk, Pim van, Physiology, Psychoacoustics and…, 5137

Previous experiments on the modulation of the McGurk effect by audiovisual coherent vs. incoherent contexts presented before the McGurk target have provided experimental evidence supporting AVSSA. Indeed, incoherent contexts appear to decrease the McGurk effect, suggesting that they produce lower audiovisual coherence hence less audiovisual fusion. — Dijk, Pim van, Physiology, Psychoacoustics and…, 5135

To provide evidence for this “binding and fusion” AVSSA process, Nahorna et al. ( 2012 , 2015 ) showed that the McGurk effect can be significantly and strongly reduced by an audiovisual context made of a few seconds of incoherent material (sounds and images coming from different speech sources) presented before the McGurk target (audio “ba” plus video “ga”): the target, classically perceived as “da” in the McGurk effect, was more often perceived as “ba”, suggesting a decreased weight of the visual input in the fusion process. The interpretation was that the incoherent context resulted in an “unbinding” effect decreasing the visual weight and hence diminishing the McGurk effect. This modulation of the McGurk effect through incoherent contexts was further extended to speech in noise (Ganesh et al. 2013 ), and a possible neurophysiological correlate of the binding/unbinding process was provided in an EEG experiment (Ganesh et al. 2014 ). — Dijk, Pim van, Physiology, Psychoacoustics and…, 5143

Categorization

• QUESTION: The unbinding mechanism — a few seconds of incoherent content durably reduces visual weight in fusion — begs the question of what temporal window and coherence threshold drive rebinding.
• XREF: Relates to the McGurk effect, the canonical cross-modal speech illusion, and prior-trial context effects studied in psychophysics. — connects to: Exposure to low-coherence audiovisual contexts reduces subsequent multisensory fusion; Brief audiovisual context can sharply weaken the McGurk fusion effect.; Audiovisual fusion is context-modulated, not automatic, and scales with audio-video coherence — Dijk, Pim van, Physiology, Psychoacoustics and…, 5177 (+5 more)
• corroborated: 7 independent passages support this claim — Dijk, Pim van, Physiology, Psychoacoustics and…, 5137; Dijk, Pim van, Physiology, Psychoacoustics and…, 5135; Dijk, Pim van, Physiology, Psychoacoustics and…, 5143

Broader Connections

• Brief audiovisual context can sharply weaken the McGurk fusion effect. #corroborates (0.95)
• Temporal audiovisual coherence strength determines visual weighting in fusion. #expands (0.82)
• Audiovisual context coherence strengthens perceptual binding of speech syllables #expands (0.80)
• Audiovisual fusion is context-modulated, not automatic, and scales with audio-video coherence #qualifies (0.75) — Dijk, Pim van, Physiology, Psychoacoustics and…, 5177
• Vision and sound expectations must concord for convincing audio-scene perception #qualifies (0.72)