I came across this today and found it quite remarkable. I’m not going to say anything more right now but, if you have a minute, test yourself with this short video.
No questions just yet – just take a look.
If you’d like to learn a bit more, then listen in to this week’s excellent Guardian Science Weekly Podcast.
Please don’t give anything away in the comments – at least for a day.
🙂
😉 Åsa
Oh crap.
I am so intrigued! But I can’t watch videos at work, so I’m going to have to wait…
Ah, bad luck Benoit.
I tested this on my wife and it worked!
Still not giving the game away until at least this afternoon to give the morning shift a go.
Oh. Reminds me of the Comedy of Errors at the Regent’s Park open air theatre. Equally surreal moment.
Thanks for your comment Frank…
…but I am going…
…to use an old trick of Brian Clegg’s…
…to bump your comment off the front page…
…because I suspect it gives too much of a hint to the unwary. 😉
Oh, sorry! I thought it was sufficiently obscure to be safe.
No worries Frank – I just thought you might be underestimating the subtlety and complexity of many of the minds at work here on NN…! 😉
The idea has recently been put to good use in TfL’s cyclist awareness campaign:
Do the test
Heehee, I’ve seen it before and now it’s easy!
Yes, and Yes! 😉
Well done for trying (to everyone who’s not seen this before)!
Andreas – nice to see that this sort of research is being put to good use. The wider implications are discussed in the podcast linked to in my post.
It is remarkable the first time you see it, eh? I have a few of these on my blog. One I found on YouTube uses a street scene; while trickier, it’s a more ‘real world’ example in some ways.
Oh, nice find Andreas. That looks like the bridge under Redriff Road by Greenland Dock, by the way.
Heh – I hadn’t actually seen this before, but I’d read about it, so I knew the trick. My count was off by 1, though 🙂
I believe they have come up with an updated one, but can’t find it just now. Their original paper is there.
I like the TFL ads with the oversize cyclists/motorcycles too.
Stephen> I guess the main thing would be how many counts people were off?! 😉 but yeah, it’s a fun thing to see. There are some other tests about the “blue and red dots that are moving and not moving” that I ended up doing in a test situation at uni a few years back. Had something to do with “how we focus on different things when the things change” and the difference when you focus on the Red ones, and only the blue move and then they change the question afterwards.
I guess there are plenty of these tests around? I still find them very fun to do (if annoying results sometimes of course)
And after you’ve done this one, try the same in the video Bob posted. I found it a lot easier there!
I only got around to Bob’s video today and hadn’t realised at all that the two psychologists behind the basketball/gorilla video shown above had been awarded an IgNobel! Or that the gorilla would reappear…
If anyone is still looking at this, I would just like to reiterate that the Guardian podcast on this (an extended interview with psychologist, Daniel Simons) is well worth a listen.
The idea that we aren’t as good at noticing things as we think has implications for many areas of our lives: witness statements in criminal trials, giving undue credence to confident speakers in meetings and our ability to watch cinema (full of inconsistent jump cuts that we mostly don’t notice).
In the US, where the death penalty still operates, people convicted — and then executed — on the basis of confident eye-witness testimony have later been exonerated by forensic (often DNA) evidence. Only slowly is the judicial system learning to place less weight on witness statements, especially confident ones who, it turns out, may not have good grounds for their confidence.
I wonder how this phenomenon also reaches into the scientific sphere? How many ‘confident’ scientists have levered shoddy data into prominent publications? I don’t imagine we are more immune than anyone else, despite our professional skepticism…
I’m just reading _The age of wonder_ by Richard Holmes. He describes how astronomer William Herschel in the late 18th c became “interested in the psychology of the observation process, and recorded the many physical tricks his eyes could play”. Later his sister Caroline compiled “an index of his remarks on practical observation”.
Maybe things are easier in our age of digital machines and computer processing of results?
Ha – you’d think!
I’m sure computerised image analysis has contributed a great deal but there is still plenty of work for the untrained amateur to do in astronomy, as the wonderful Web2.0 project Galaxy Zoo demonstrates.
Enjoy the rest of the book – I really liked it (though it’s a bit patchy).
I totally fell for that the first time I saw it. i was so angry LMAO
Now I’m wondering if this sort of test works best as a video. If you were watching a live demo, I guess the gorilla would be a lot easier to spot.