A new twist on an old illusion.

The monkey business illusion.

Did it work on you?

This video is great especially since most people studying psychology have seen the original gorilla video. This even worked on a group of the most important vision scientists in the world at a recent Vision Sciences Society annual meeting.

Also, check out the invisiblegorilla.com for more videos and posts by Dan Simons!

More like this


On their website, they have a few more videos, including the *original* gorilla video, the door illusion, and a presentation of the above video to a large group that includes yet another twist (and I don't mean that he wears a gorilla suit at the podium).

I saw another illusion like this, so I noticed the gorilla. I didn't see the black player actually leave the scene, but as the gorilla left I noticed a player was missing and figured she left around the time the gorilla entered (which was true). I totally missed the color change of the curtain.

That little twist is actually me ;)

By The Omnibrain (not verified) on 16 May 2010 #permalink

I counted the passes and missed a couple, and I saw the gorilla, noted that the stage wasn't any more crowded, but didn't explicitly note a lost player. I didn't notice the curtain changing.

I wonder what the distribution of counted passes is in the gorilla-noticer groups and the prior-video-viewer groups?

Why do you call it an illusion?

You set a specific task as to activity in a very crowded scene involving two stated events series.

I counted 16 passes, probably because at two points I thought I missed a pass and so added it in even while continuing to count.

Nonetheless, if given that kind of assignment, that kind of accuracy is positive and demonstrates an ability to mentally screen out what is extraneous to task.

Had you assigned the task of recording all the events on screen, or anomalies on screen, I suspect in my case at least, my scoring, because of my ability to narrow or broaden my concentration to task, is good.

Therefore the only conclusion I can make as to your little game is that it is nothing more than trickery passing as scientific study although you folks may think otherwise.

In that case the deluded are yourselves.


By Jack Jersawitz (not verified) on 18 May 2010 #permalink

Wow Jack,

You're a complete ass and have clearly missed the entire point.

Thanks for you insight!

By The Omnibrain (not verified) on 18 May 2010 #permalink


An illusion often has misdirection at its core. Don't be a "sore loser." You weren't meant to accurately do anything. It's an insight to how the brain works in terms of perception of complex events, particularly when trying to concentrate on one aspect of a situation. It has many scientific implications as well as the fact that it should change the way that eyewitness accounts are used in courts and police investigations.

I don't get why it's called an illusion, I noticed everything. Plus, how could you not notice the gorilla?

you see it because you expecting to see a gorilla
when my teacher show this video on class, almost noone realize that a gorilla passing by because they are to focused on the ball that passed around