This Is Really Wild — The McGurk Effect

So a little while ago I discovered ThinkGeek this has been a wonderful terrible thing.  Wonderful because there are more than enough incredibly awesome useless gadgets to keep me entertained for a few lifetimes.  Terrible because within minutes of checking out the site I had already purchased a universal remote for my key-chain, a packet of miracle berries for some friends and I to play with, an old school usb cell phone attachment for my brother (x-mas gift) and a book on cognitive neuroscience called Mind Hacks.  As fun as all of the above have been, it’s the book that has inspired this argument.

It’s basically a primer on cognitive neuroscience.  Trust me, that kind of thing is actually fun to read if it’s well written.  Most chapters actually include some easy try-at-home experiments that demonstrate interesting little things about how your mind works.  One of the coolest ones I’ve come across so far is the McGurk effect.

To experience the McGurk effect, scroll down and watch the video of the dirty looking white guy at the bottom of this post.  Listen to what he’s saying.  Make sure you watch him as you do this.  What sound is he making?

Most people hear “Da Da” when they watch this video.  A couple times I’ve also heard people tell me it sounds like “La Da.”

Now close your eyes or look away and listen without being able to see the video.  You can now hear him very clearly saying “Ba Ba.”  What’s going on?

In reality, our dirty white guy here was filmed saying “Ga Ga” but the audio that goes along with the video is of him saying “Ba Ba.”  Your eyes and your ears are giving you conflicting signals so your mind interprets them as a sound that can make sense of (for the most part) both sources of input.  The wild thing is that now, even though you know he’s saying “Ba Ba” you can still only hear “Da Da” when you’re watching his mouth, no matter how hard you try to hear the correct sound!

It’s a really cool reminder that the “sounds” we hear are not actually floating around out there.  It’s just the way that our mind interprets vibrations picked up by our ear drums, and obviously it takes more than one sense into account.

Pretty cool.

Now I’m off to go buy a Titanium Spork.  What in the world could I ever need a Titanium Spork for?

…

…quit asking stupid questions.