demonstrations:the_mcgurk_effect
The McGurk Effect
Materials: ★☆☆ Easy to get from supermarket or hardware store
Difficulty: ★☆☆ Can be easily done by most teenagers
Safety: ★☆☆ Minimal safety procedures required
Categories: Senses and Perception, The Brain and Nerves, Psychology
Alternative titles: Do You Hear What You See?
Summary
The McGurk effect occurs when conflicting visual and auditory cues lead the brain to misinterpret what sound is being heard. By combining mismatched audio and video of a spoken word, students can observe how visual information influences auditory perception.
Procedure
- Record a person repeating a simple word, such as “pie,” ensuring both audio and video are clear.
- Make a second recording of the same person saying a slightly different word, such as “bye” or “guy.”
- Create a video that plays the audio from the first recording while showing the video from the second recording.
- Ask volunteers to watch the video and report what word they “hear.”
- Repeat the test with volunteers closing their eyes while listening to the same audio.
- Compare results to see how strongly the visual cues affected perception.
Links
McGurk Effect (with explanation) - brainrulesbook:
📄 Putting the McGurk Effect to the Test - Science Buddies: https://www.sciencebuddies.org/blog/putting-the-mcgurk-effect-to-the-test
Variations
- Try using different word pairs (e.g., “ba” vs. “fa”).
- Test with larger or smaller groups of volunteers to compare consistency.
- Examine whether age or prior knowledge of the McGurk effect changes results.
- Use video editing software to slightly misalign the audio and video timing.
Safety Precautions
- No physical risks are involved.
- Remind participants that this is a harmless perceptual illusion.
Questions to Consider
- Why does the brain sometimes prioritize visual information over auditory information? (Vision often provides more precise cues for speech in noisy environments.)
- What happens when participants close their eyes? (They usually report hearing the actual audio word, since no conflicting visual information is present.)
- How might the McGurk effect relate to technologies like virtual reality or video conferencing? (It shows how mismatched audio and video can alter perception and understanding.)
- Do all participants experience the effect equally strongly? (No, sensitivity to the McGurk effect can vary among individuals.)