psychopyko » illusion

Quirks of being human

pyko — Thu, 10 Jun 2010 13:43:33 +0000

We are all human, yet we are all different from each other, we are all unique; or as someone put it "You are unique, just like everyone else." However, for the majority of us, no matter how "unique" we are, we are still human...which means most of us are susceptible to quirks in how our brain works.

So what is all this random rambling about? Well for those that are unaware, I enjoy understanding and learning how the human mind works - especially when it doesn't quite work as expected, such as when we see optical illusions. So here are a few that I would like to share.

Impossible Motion: Magnet-Like Slopes

Our brain doesn't always decipher what we see with our eyes in the real world properly. It tries to be too smart and often fails. But that's ok, since it means we can see awesome optical illusions!

Change Blindness

You've probably heard of this before - as humans we can be very "blind" to how our environment changes around us. Some rather big changes can occur and we don't notice at all.

Another change blindness example - just for fun

Leaning Tower Illusion

So what about a still image, no videos, just a plain old image. How will your eyes (or should I say brain) trick you now?

The two images are identical...really!

That's it for now - hope you enjoyed the random selection above What I find most interesting is that for many of these "brain quirks" even though you know what is happening, even though you know the trick you still can't un-trick your brain to see what is really there.

dragon illusion

pyko — Wed, 19 Sep 2007 03:08:52 +0000

Another great illusion - and this time you get to make it! Have a look at the Three Dragons from Grand Illusions - the movie clip is really quite cool! After seeing the clip I actually went and made it straight away (much easier to make than the penguin) but sadly it didn't turn out as nice as the illusion in the video clip. It seems like you need some light behind the dragon for it to work. Though I'll still put it on my desk at work and see if I get any weird looks

Must say this time I had no idea why this illusion works, other than the random guess of our brains getting tricked yet again. However there is a short explanation on the website:

If we move around when viewing a solid object, our brain knows how the object we are looking at should behave. However the dragon gives us the wrong clues, because we mis-interpret what its shape is. We assume that the nose of the dragon is pointing out towards us, but in fact the dragon's head is concave.

So I guess since our brain makes up for the head being concave, it also somehow makes the dragon's head follows us!

Another similar illusion (which I presume works on the same principles) is the Einstein Hollow Face Illusion. If you haven't heard of it or seen it click on the link and have a look at the video. In fact, I can't believe I've just found this website, it is chockablock full of great illusions (or should I say Grand Illusions =P).

Update (25/09/2007)
I am no longer disappointed with the dragon as I managed to see the illusion few days ago! Started off with my random decision to film the dragon and since that turned out so well, decided to give it another go. Here are some tips to help see the illusion if you still can't seem to see it:

Stand about an arm's length away from the dragon
Close one eye (this really helps a lot!)
Place the dragon so you're looking at it roughly eye level
Position it so you can see the ears clearly (so not front on, but on a slight angle)
Convince yourself that the snout is pointing out

Once you've convinced yourself the snout is pointing out you should be able to move your head around and the dragon's head should follow If you're still finding it hard to see the illusion, take a step back and try again. It is quite hard to see the illusion with both eyes, but I find if you take a few steps back and not concentrate too much on it you might get a glimpse of the illusion.

The first time seeing the illusion in real life is the hardest, but once you've seen it, it is much easier to see it again (but just as amazing). A cool thing you can try when you're seeing the illusion is to touch the snout - now that you can't do with a film.

clear as black and white…right?

pyko — Tue, 11 Sep 2007 12:28:12 +0000

The image above probably looks very normal - a set of everyday chess pieces (without pawns). White pieces on top covered by black clouds, and black pieces at the bottom covered by white clouds. If they don't look like chess pieces, try clicking on the picture to enlarge it - my friend thought they were teeth when he saw it on my msn display pic!

So, if we are imaginative, and assume the chess pieces are real, it would make sense that we can use them and play a normal game of chess...right? Well, not quite - because the chess pieces are identical. They are the same - pixel for pixel. If you don't believe me 'cut and paste' the chess pieces and they will magically "change colour". Even if you believe me you can give it a go, quite mind blowing if you ask me!

When I first saw this picture in a psychology lecture and I was confused as to why the lecturer (Bart) had put the image up, until he said "It's an optical illusion, the chess pieces are the same." I think most people in the lecture had a sudden "no way" moment - I certainly did!

After the lecture, I tried to replicate the illusion (without much success) until I stumbled across the article Image segmentation and lightness perception that was published in Nature. Funny thing is the lecturer was actually one of the authors of the article - no wonder he used it in his lecture. My understanding of the illusion is that our brain takes some shortcuts when processing the image, and therefore it 'cuts' the image into segments which may not necessarily be correct, thus causing the illusion. For a better explanation read the article - it's quite interesting.

There are a few other optical illusion on Bart's homepage (go into Cool Demos), some of them are quite cool, but a must see is the moving version of this illusion. If you ask me THAT is really mind blowing!

Oh, and if you want to see my attempt to create the illusion have a look at my deviantID.

shoe print illusion

pyko — Tue, 04 Sep 2007 12:30:15 +0000

Was going to post this up last week, but then saw the free penguin/tux and I just had to post that first Anyway, this is the first of hopefully many cool optical illusions that I will post up. I love optical illusions, and I'm going to try and post up "rare" illusions on my blog - so stay tuned!

In my opinion, this illusion is extra cool because nothing was done deliberately to get the illusion effect. The photo was actually taken by Marty, and every now and then it appears on her laptop slideshow screensaver (everytime it appears I point at it and go psycho )

The amazing illusion...

The illusion reminds me of something I read ages ago on the Internet - someone had saw footprints on the sand, but instead of being imprints, they were coming out from the ground...like if people were walking on the other side of the ground. I vaguely remember seeing a photo of the "inverted footprints" and thinking 'Wow, how is that possible? If it was photoshopped whoever did it must be really skilled!'

However, I know better now...it is in fact an optical illusion! Try this - save the image and rotate it 90 degrees counter-clockwise...the shoe prints should now appear normal. If I'm not mistaken (from my very limited knowledge from one session of psychology), the reason the the illusion we see this illusion is because the way our brain works.

As humans, we are accustomed to light coming from above us, probably because the main source of light is the sun. Therefore, our brains are wired to automatically calculate if things bulge out or cave in depending on the shadows. I think that is why when you rotate the photo (and therefore changing the location of the shadow) the shoe print flips back and forth. As with most optical illusions of this kind you can force yourself to flip between the two states.

Oh, and the other cool thing (also from psychology) is if you didn't bother to save the image and rotate it, but instead just tilted your head it would probably look more or less the same as the upright image. Again, because our brain automatically goes "you're tilted, so the world is tilted, let's un-tilt what we are seeing now". Same concept as when you just wake up and see your clock/door/room - you don't freak out and think your room has turned on it's side, in fact it seems rather upright. Amazing isn't it!