A few days ago a psychologist named Ulric Neisser died. I never met Ulric, but I did read much of his work when I was an undergraduate, including this wonderful monograph on John Dean’s distorted memory during the Watergate Scandal.

Neisser also carried out some wonderful work into perception, and created one of the first videos demonstrating the power of inattentional blindness. In the Neisser video you have to count the number of basketball passes made by the team wearing white shirts…..

….and you miss….well, you know what. It was this video that inspired Dan Simons to make his wonderful basketball video…..

….in which you miss…you know what. And Dan’s video was one of the main sources of motivation behind me making my colour changing card trick video…..

….in which you miss….well, you know what.

And that’s what great about science. Your work doesn’t die with you, but instead leaves a lasting legacy for future generations. In many ways, you live forever. Ulric, your work showed that people often don’t see what is right in front of their eyes. We shall miss you too.


  1. Thank You Richard for reminding me about this. I know all these experiments and I think they are fantastic. I use them often to explain inattentional blindness. Thank you Ulric, Dan and Richard.

  2. I once changed the colour and pattern of my top four times in front of a guy I was sitting in a pub with, three times while he was away from the table and once while he was sitting at the table – right in front of him – and he didn’t notice any of the changes. I’m only glad that we were just good friends after that display of inattentional blindness!

  3. The gorilla trick never worked for me, even when unwarned… I guess I never paid enough attention to the things I was supposed to count or follow…

    But the great colour changing card trick literally blew my mind the first time I saw it.

  4. It was the card-trick that brought me to this very blog… I was shown it in my psychology class and the link at the end sent me here 🙂 My condoleances to Neisser’s family 😦

  5. OMG! I was feeling smug because I saw the obvious gorilla; then I felt smug because I thought “oh it’s an obvious deck-switch”; then I didn’t notice any of the four colour changes!

  6. I tried counting the passes on the second video, at some point thought it was a trick and the people made invisible passes which I could not count, and thought (I may have already missed a few), and then I saw the gorilla and thought it was a trick to misguide me on counting. At the end I had counted wrong but I saw the gorilla. Is that the trick? U cannot do both?

    1. The trick is that a lot of people are so much concentrating on counting the passes that they don’t notice the gorilla at all.

  7. astrologia vive para siempre ahora que la epigenetica explica como afectan a una embarazada y su feto: luminosidad del 3º mes de gestacion, frutos tipicos de ese mes y stress de de la actividad tipica de ese mes (cierre contable del año, vacaciones, comienzo de actividad laboral, etc)

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