Visual Illusions:
I frequently hear people imply, if they don't state directly, that two working eyes are required for depth perception. This is surprising because with a moment's reflection, it's easy to see that there are depth cues that don't require both...
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Posted on November 19, 2007 11:10 PM • 1 Comments • 0 TrackBacks
Cool Stuff: And right now, I'm doing some stuff with motion aftereffects, so I've been looking for them all over. This one rocks (it's even better if you watch it in full screen mode):...
Posted on November 9, 2007 12:45 PM • 3 Comments • 0 TrackBacks
From Anstis & Casco, 2006, Movie 1, p. 1088 OK, here's a really, really cool illusion published last year, and that I learned about only recently. To see it, go to Stuart Anstis' page here, watch the first movie...
Posted on October 20, 2007 9:58 AM • 9 Comments • 0 TrackBacks
Everybody knows the Margaret Thatcher Illusion. If you've forgotten about it, here's the best example I've found (from Schwaninger et al.1) Both the top and bottom pairs are the same photos, but they look very different depending on whether they're...
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Posted on September 19, 2007 9:00 AM • 8 Comments • 0 TrackBacks
Everybody's seen Kanizsa's triangle: It's a simple illusory figure illusion, first reported by Kanizsa(1). The illusion is likely caused by the processes that the visual system uses to separate figures from their ground(2), but to date there doesn't appear to...
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Posted on May 20, 2007 1:44 AM • 13 Comments • 0 TrackBacks
In honor of the announcement of the Best Visual Illusion of the Year (via Steve), I thought I'd revive the old cool visual illusion series. I may post about this year's winner, the leaning tower illusion, in the future, but...
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Posted on May 15, 2007 4:13 PM • 0 Comments • 0 TrackBacks
One of my favorite perceptual illusions isn't actually visual. It's often called the "cutaneous rabbit" illusion1, for reasons that will be apparent in a moment. I stumbled across it when reading a paper by Dennett and Kinsbourne2. Here's their description...
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Posted on November 18, 2006 6:40 AM • 1 Comments • 0 TrackBacks
In keeping with the theme of illusions that result from crossmodal interactions, this week's illusion is the ventriloquism effect, first reported by Howard and Tempelton in 1966. As you can probably tell from the name, the ventriloquism effect involves...
Posted on November 11, 2006 9:30 AM • 0 Comments • 0 TrackBacks
Last week, I talked about the sound-induced flash illusion, in which presenting a single flash with two or more auditory beeps caused people to see two or more flashes. This week, a study showing that the same effect can be...
Posted on November 4, 2006 10:08 AM • 2 Comments • 0 TrackBacks
You may have seen this illusion in a post from earlier in the week over at Cognitive Daily, but I thought I'd say a little bit more about it, and talk about a related illusion. First, click play (from Sham's...
Posted on October 28, 2006 9:08 AM • 1 Comments • 0 TrackBacks
I was reminded of this illusion by the Seed Daily Zeitgeist yesterday. In order to get the full effect, I'll show you one set of photos here, and the rest of the post will be below the fold. The first...
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Posted on September 23, 2006 9:06 AM • 26 Comments • 0 TrackBacks
This week's visual illusion is related to Mach bands, and similar in some ways to the watercolor effect. It's called the Craik-O'Brien-Cornsweet effect (or just the Cornsweet effect)1. This is the best example I've ever seen (from here): What you...
Posted on July 8, 2006 10:38 AM • 3 Comments • 0 TrackBacks
Discovered in the 1860s by Ernst Mach (hence the name), Mach Bands are actually a set of interrelated phenomena. Take a look at this image: From here The individual bands should appear as gradients, and they may even appear to...
Posted on July 1, 2006 8:20 AM • 0 Comments • 0 TrackBacks
Here is an illusion that was discovered relatively recently. Take a look at this (from here): You should see two figures with a purple outter border and an orange inner border. What color is the interior of the figure? It...
Posted on June 24, 2006 12:00 PM • 3 Comments • 0 TrackBacks
In yesterday's post on afterimages and aftereffects, I mentioned that demonstrations of neural adaptation for a particular feature (in the post, I used the examples of color and motion) is generally taken as evidence of the existence of specific neurons...
Posted on June 18, 2006 5:18 PM • 0 Comments • 0 TrackBacks
Most of you have probably seen this before, but if you haven't, look at the flag for 30 seconds (if it doesn't work with 30, try 60), and then look at the white space underneath it. You should see a...
Posted on June 17, 2006 12:35 PM • 2 Comments • 0 TrackBacks
As you all know, I love visual illusions, and this may be one of my favorites. This picture is pretty small (go here for a bigger version), but you should be able to figure out what's going on by watching...
Posted on June 11, 2006 11:00 AM • 2 Comments • 0 TrackBacks
Cognitive stuff from a cognitive person. If you've got any requests, drop me an email. If it takes me a while to get to it, drop me another one.
