My favorite type of illusion is what Wikipedia tells me is called a “robust illusion” – the type that doesn’t depend on being tricked. Robust illusions work even when you’re told exactly what mistake your brain is going to make – the prior knowledge doesn’t matter. Our brains still screw it up reliably.
I used to face this illusion every day – our dorm elevators are set to stay on the 1st floor for an irritating and inconvenient amount of time, no matter how many times you press your floor or the “close door” button.
Pressing that button made me feel better even though it doesn’t work, has never worked, and never will work. Because my brain is stupid.
(Maybe ‘stupid’ is too strong a term. But at the very least, my brain is willfully ignorant.)
Luckily, my brain isn’t alone: a friend sent me a video of “The McGurk Effect” (it starts at 0:38), telling me it was this awesome thing where a guy says “Bah, bah, bah” to a video recording of him mouthing “Fah, fah, fah”, and you actually hear the “Fah”s because your brain gets confused and decides to make the sound up out of nowhere.
I was skeptical, then floored when I actually heard the “Fah”. I couldn’t believe it worked even though I knew exactly what was going to happen.
It’s a must watch. I promise it’ll blow your mind.
I went searching for journal articles on it and they didn’t make me feel any smarter – how am I supposed to trust my brain when it can be such a liar?
(The Cliff’s Notes version of the linked article:
Auditory Processing Center: Okay, he’s saying “Bah”, so –
Visual Processing Center: Cool, yeah, but he’s saying “Fah“. Go tell the Auditory cortex.
Auditory Processing Center: What? No, that’s not it at all, he –
Visual Processing Center: Yeah, whatever. I win, screw you. AUDITORY CORTEX?
Auditory Cortex: ‘Sup.
Visual Processing Center: He’s saying “Fah”.
Auditory Cortex: Cool. I’ll go tell the frontal lobe. *leaves*
Auditory Processing Center: … I hate you.)
Action Potential 
Awww, your video has been blocked because of copyright problems. Booo.
The day I realized I couldn’t trust my brain came when I was in my Cognitive Psychology class and they showed us a video. They told us to count the number of times a basketball was thrown to a person in a white shirt. There were black shirt people and white shirted people all moving around in a circle throwing the basketball everywhere. I counted 17, and I was proud.
Then, the professor asked us how many passes we had counted. We discussed that for a while. Then he asked, “How many of you noticed something weird in that video?” Only about 20% of the class of 200 people raised their hand. He replayed the video, and in the middle, a guy in a gorilla suit walks into the frame. He goes into THE MIDDLE OF THE CIRCLE, and stands there while the basketball is being passed around him. He dances around for a bit. Then he leaves.
Honest to God, I did not see him. WHAT ELSE ARE YOU HIDING FROM ME BRAIN?
Got a new video link – try again!
Dude, that gorilla video mystifies me – I definitely watched it last summer, and was intent on counting the number of passes, sure – but that’s no excuse for totally missing a gorilla! I couldn’t believe it!
I should link to that one too, really. Forgot all about it!
Me, too: “Gorilla? There was a gorilla?” I felt like an idiot.
My law enforcement family members tell me that’s why they don’t rely too much on eye witnesses.
Video content blocked.
Here is a different video that demonstrates the McGurk Effect.
http://www.metacafe.com/watch/330773/hearing_lips_and_seeing_voices_the_mcgurk_effect/
Ack! Thanks!
That was awesome! It’s amazing how our brains can rationalize conflicting data. It makes me wonder to what level that type of rationalization rises. Begin metaphysical daydream now…
AP, your posts are starting to make me spew/choke on my coffee on a regular basis. I cant wait for the dat when you team up with ZDoggMD and make an educational rap video about bacterial vaginosis.
Take this one step further and imagine the suffering of someone with a psychiatric illness. “Reality” cannot be trusted.
That video is so cool. Didn’t trust it at first so I hit rewind, waited to hear the first “fah”, closed my eyes and boom, back to “bah”. Opened them again and right back to “fah”. Crazy, but so neat. I’ll have to pass that video around, thanks for posting that!