Thursday, 8 July 2010

Spot the changes

Would you notice if I was switched with another person while we talked? What a silly question, you might reply. You can't get swapped out in a conversation, and if you were talking to someone, and not asleep, surely you'd notice if your conversation partner was changed for a new person. Oh, but you'd be oh so very wrong. Watch this short video, as a man asking for directions is changed out before two people's eyes, and neither of them notice that the person they were talking to is gone.

The problem is our brain is too good at filling in the gaps, and ignoring things it thinks are irrelevant. Much of what we see in our day to day life is a broadly painted picture, with our brains filling in the blanks with patterns from our previous experience. This makes eye-witness testimony some of the most unreliable and weakest of the forms of evidence. It's ironic that in law, eye-witness evidence is considered some of the strongest.

Edited to add: I forgot two things. First, I want to hat-tip Neuroskeptic for an article that had the video. Second, I want to link this other, more amusing video. In it, the person is not just swapped out for another White male with a similar hair cut, but by a bald White male, Black male, a much shorter Asian female, and a variety of other people. You'd think people would notice when the appearance and gender of the person they're talking to radically changed!


Alaskan Dave Down Under said...

We'd all like to think we wouldn't fall for it, but it's quite well done. Big city, lot's of anonymous pedestrians, attention is immediately focused on map, switch occurs before the person can get a fix on who they are talking to, and then attention right back on the map. Wouldn't work in a non-crowded setting though, like Squarebanks.

And it was phunnie, too, also.

TwoYaks said...

I thought distractability is a big feature, but I've been poking around and the studies seem to suggest that isn't the case. The original experiment was done in a quiet office where the there's only the subject and the swapping pair. The person ducks down to file something, and a second person pops up. 0% of the participants noticed the change.

This is on the heels of an experiment where subjects are told to focus on a movie of a person standing up, walking to the camera, and then walking out the door. The camera swaps to another view as he walks over and talks on a phone. In the camera swap, the actor is changed, substantially. People fail to notice.

The experiments would sugguest it's not distractability, but that we encode incredibly little information when it comes to strangers...

gpc said...

Frankly, I find it reassuring. When I was in high school, my little sister changed her hair color a dozen times within a 2-week period and I never noticed. She still, lo these many years later, thinks it's hysterical. Now I can tell her that 50% of the population would have been equally oblivious.