Notes from a Linguistic Mystic

Here at LinguisticMystic, I do my best to post things of interest to everybody, not just linguists. So, in the interest of wider public appeal, I’d like show off one of the stranger things to ever come out of research in Phonetics and Psycholinguistics: The McGurk effect.

Before I talk any further, you should get a demonstration. Watch the following short video, with your sound turned on. First, watch it a few times, and decide what the man is saying. Then, shut your eyes and re-play the video a few more times, with your eyes closed through the whole movie.

The Video: The McGurk Effect Demonstration

Kinda freaky, huh? When you watched it with your eyes open, you likely heard “Da Da” (or something similar). However, when you shut your eyes, he was clearly saying “Ba Ba”.

This effect is caused by the fact that in conversation, we frequently watch the other participants’ mouths moving, just to reinforce what’s being said. Generally, this works relatively well (just ask somebody who can read lips), but here, the makers of the video are messing with us a bit. The sound is a recording of the speaker saying “Ba Ba”, but the video shows him making the mouth and lip movements for “Ga Ga”. When presented with this conflicting data, some strange little loop in the brain of 98% of adults merges the two, giving us the final perception of “Da da”. This effect was first described in a paper called “Hearing lips and seeing voices”, by Harry McGurk and John MacDonald.

Truthfully, I don’t quite understand how this works, and I’m sure there’s a whole bevy of psycholinguists working on that as we speak. However, it’s a really cool effect, and it underscores the idea that what we perceive can be affected by other factors beyond our control.

So, really, I don’t have to post any interesting content here. I’ll just post boring stuff, and then make it look like it’s REALLY cool. That way, your brain will average it out. Or, you know, not. Yeah, probably not. Worth a try, though.

For more information on the McGurk effect, visit: (Includes Higher resolution versions of the above video)

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