Audition controls the flow of visual time during multisensory perception.

Area of Science:

• Cognitive Psychology
• Neuroscience
• Speech Perception

Background:

• Previous research on audition-vision interaction primarily used non-speech stimuli.
• Multisensory processing in speech perception remains an active area of investigation.

Purpose of the Study:

• To introduce and investigate the Audiovisual Time-Flow Illusion in spoken language.
• To determine the influence of auditory input on visual speech perception.

Main Methods:

• Participants were presented with manipulated auditory speech stimuli (pauses inserted/portions removed).
• Visual speech stimuli were presented concurrently with manipulated auditory stimuli.
• Participants reported their perception of the visual speech, which was presented intact.

Main Results:

• Auditory manipulations led participants to perceive intact visual speech as pausing or skipping.
• Reversing the manipulation to the visual stream did not elicit a similar illusion in the auditory stream.
• This indicates a directional influence from audition to vision in speech processing.

Conclusions:

• Auditory input plays a dominant role in synchronizing audiovisual speech perception.
• The auditory modality dictates the perceived pace of visual speech, establishing the Audiovisual Time-Flow Illusion.
• This finding highlights the crucial role of audition in multisensory integration during spoken language comprehension.