Illusions from combining senses: the McGurk Effect!

Are you familiar with the “Yanny or Laurel” debate? If so, which name did you hear? Did what you hear ever change if you were reading one of the names when listening to the sound?

 If you answered “yes” to the questions above, then you might’ve experienced something called the McGurk Effect!

Our experience of the world is essentially a combination of our different senses. This understanding varies depending on how our senses interact with each other. There are times when your different senses are picking up on conflicting inputs, like if you smell pizza, but the only food you can see around you is an apple. One example of this interaction is the McGurk Effect.

The McGurk Effect is when what you hear is influenced by what you are seeing at the same time. This phenomenon was accidentally discovered in 1976 by cognitive psychologists Harry McGurk and John MacDonald. They were using audio tapes and videos to study babies’ perception of the sounds and images of spoken language when they found something interesting: even though McGurk and MacDonald knew that the audio recording played one specific syllable (e.g. “ga”), and the video showed a person mouthing a different syllable (e.g. “ba”), they would hear a third, totally different sound (e.g. “da”)! They soon came to understand that this experience was not a mistake, but rather a characteristic of human perception.

Interestingly, the McGurk Effect varies in intensity depending on the language spoken. For example, it is not as strong in Chinese or Japanese compared to Spanish or German. However, something that is common across all tested languages is that, when the audio is unclear, then participants will resort to the visual aid to help them understand the sound.

We also made a TikTok showing the McGurk Effect in action– check it out here and see if you get the illusion:

@babiesandlanguage

Your brain uses information from multiple senses to make sense of the world, including the speech you hear and see! #McGurkEffect #Linguistics #Language #illusion #Senses #psychology

♬ original sound – Babies and Language Blog