Right vs left Brain optical illusion

[Liberal]

@Throatwarbler Mangrove

For those of you who claim you can “change it at will”, do you feel the same effect when looking at other spinning images?

:dubious:

Excuse me? I for one did not claim; I reported. I can change the spin direction of this particular image at will. If you have some other image for me to look at, I will report to you what I observe of it.

:mad:

[Aholibah]

@Chief Pedant

a silhouette, because it reduces three dimensions to two, will look identical with either direction of rotation.

So then, is it impossible to create a ‘spinning silhouette’ animation that only appears to spin in one direction?

[chorpler]

@GuanoLad

Whether people can see it go one direction or the other is neither here nor there. The question in my mind is does it really indicate you’re “left brained” or “right brained” as per their list?

And I say no, they’re completely wrong.

Oh, yes, definitely they’re wrong.

[ianzin]

@Rick

There are two pictures.

1. What Rick said is correct. There are two images. The easiest way to notice this is that sometimes the left leg is raised, sometimes the right leg. For each individual observer, this affects which way she seems to be spinning. As Rick said, they seem to switch images after about 30-40 seconds.

2. Even if the image did not change, I think that most people would have a ‘dominant’ interpretation but could ‘persuade’ themselves to see an alternative interpretation if they tried. Simple home experiment: straighten out a wire paperclip and bend it into an abstract wire shape. Hold it in front of strong light so that it becomes a silhouette. Slowly twirl it between your fingers so that it is revolving, say, clockwise. Look at it with one eye. You can persuade yourself to interpret the rotation as either clockwise or counter-clockwise.

3. This left brain/right brain stuff is largely exaggerated and mis-represented in the popular press. Even if there is some evidence to suggest that the two halves of the brain have distinct sets of primary responsibilities, I’m not sure this necessarily equates to any meaningful way to categorise people. The way this kind of thing is represented in the pop media is self-defining nonsense. Some people may have more aptitude for, say, logical tasks than others. Ergo, we are told they must be ‘left brain’ people. But this is an assumption. For all we know, 50% of those who are very logical have a ‘dominant’ left lobe, and 50% do not. Unless we actually slice open their brains, take a look and can detect a significant and physical distinction, we are making guesses.

[Indistinguishable]

@ianzin

1. What Rick said is correct. There are two images. The easiest way to notice this is that sometimes the left leg is raised, sometimes the right leg. For each individual observer, this affects which way she seems to be spinning. As Rick said, they seem to switch images after about 30-40 seconds.

No, there are not. As others have noted, you can go open this up in your favorite image editor and see. What’s happening is that you are mentally reinterpreting the raised leg as either the left or the right leg; from this silhouette alone, it is not possible to determine which is which. (In fact, this is another great way to switch your perception; try to rethink of the raised leg as the right or the left one).

[Colophon]

Weird, when I first saw it, I was looking at her, um, upper body and saw it as anti-clockwise, but then when I look at her legs it’s clockwise because of the shadow.

So I think this is really a test to see whether you’re a breast or leg man

[ianzin]

@Indistinguishable

No, there are not.

Thank you for this correction. I replied too hastily the last time. Apologies.

[jovan]

@ianzin

1. What Rick said is correct. There are two images. The easiest way to notice this is that sometimes the left leg is raised, sometimes the right leg. For each individual observer, this affects which way she seems to be spinning. As Rick said, they seem to switch images after about 30-40 seconds.

It’s been said several times now but there are 34 frames in this animation. That’s all. Playing it back frame by frame, it still works and it’s even easier to change the direction. With a little observation, one can also see where the ambiguity lies. With the exception of frames #6 and #25, which show the dancer in profile view, all other images can be interpreted as her either facing front or back. The middle frames (#13 to #18) are especially ambiguous but with a minimum of concentration, you can see her facing either way with the animation stopped.

This makes this illusion similar to the classic Rubin vase or the old woman/young woman illusions: your brain has to decide between two equally likely interpretation of the retinal image.

I did a quick search of research papers and couldn’t find anything on this particular illusion. What may be interesting is that while it might appear to be a motion perception-related illusion, it also works as an ambiguous illusion when viewed as still images.

[Shagnasty]

@Colophon

Weird, when I first saw it, I was looking at her, um, upper body and saw it as anti-clockwise, but then when I look at her legs it’s clockwise because of the shadow.

So I think this is really a test to see whether you’re a breast or leg man

Funny, she hovered full frontal in my gaze so I guess that goes to show I like it both ways.

[Quint]

What do you suppose the results would be if it was a guy with a boner instead of a woman with implants and perky nipples? The feminist perspective needs its’ pound of flesh (so to speak).

[chorpler]

@ianzin

1. What Rick said is correct. There are two images. The easiest way to notice this is that sometimes the left leg is raised, sometimes the right leg. For each individual observer, this affects which way she seems to be spinning. As Rick said, they seem to switch images after about 30-40 seconds.

The strange is that there is no left or right leg, strictly speaking – either leg could be left or right depending on how you’ve interpreted it. There’s a very similar example in Rudy Rucker’s book The Fourth Dimension showing a 2D drawing of the outline of a hand, and you’re supposed to decide if it’s a left or right hand. But of course it could be either, depending on whether you think the palm is facing up or down. (Obviously this only works with a simple drawing where you can’t tell if you’re supposed to be looking at the palm or the back of the hand.)

[Princhester]

@mr. jp

I would additionally like to note that, scientifically speaking, that dancer is damn hot.

Seriously, is the particular image used deliberate? One of the first things I noticed when I looked at this was that the image has been drawn with hard nipples. I mean, why? Is it because

1/ it was just done to cause more people to bother thinking about the illusion at all ie made it more popular on the internet because it looked sexy

2/ the person putting the illusion together borrowed a .gif which just happened to be slightly saucy

3/ distraction of the brains of those interested in the female form assists with creating mental confusion and makes the illusion work better

I mean, the pixels representing her nipples didn’t just happen. I’m interested in what the rationale was here.

[Sapo]

You guys know that there are, well, actual porn sites all over the internet, right? Let’s try to focus here.

I am really curious about every person who sees this spin anticlockwise. Are you considering the shadow? The shadow makes it very clear that the raised leg moves right to left in front of the body, which makes this clockwise.

Someone mentioned seeing the shadow as on a translucent surface from below. Is that how other people who see this counterclockwise are interpreting it? Or are you just ignoring the shadow?

[nivlac]

Looking at the whole figure, it’s strictly counter-clockwise for me. BUT… if you cover the top and just look at the legs, then it’s looks clockwise. It really depends on whether you see the leg on the ground as the left leg or right leg. Nice illusion.

[jovan]

@Sapo

I am really curious about every person who sees this spin anticlockwise. Are you considering the shadow? The shadow makes it very clear that the raised leg moves right to left in front of the body, which makes this clockwise.

No, the shadow is ambiguous as well. Like I wrote in my previous post, this isn’t a motion illusion: each individual still frame is ambiguous. The woman either faces front or back. Both interpretations are equally valid and the shadow is consistent with that.

Instead of watching the animation in your browser, open it in a program that allows you to control playback. I used Quicktime Player. Look at the very first frame. Is she facing front or back? If you see her facing back, with her right leg pointing away and down, she will appear to move clockwise. If you look at her as if she’s facing you, looking slightly up, and with her right leg pointed towards you, and up, she will appear to move counter-clockwise.

[What_Exit]

@Throatwarbler Mangrove

Well, either I’m the one being whooshed here, or you guys need to cut back on the acid, because it’s plain as day that the picture simply switches after a set time. Just watch it for 30 seconds or so. They purposely chose an image that’s distracting(woman) and hard to focus on, and notice that you only see a silhouette, which would make the transition seamless (if you could see any other details on the model, the change from clockwise to counterclockwise would be too obvious). If you look away for a moment and the direction changed, it just means the direction changed while you were looking away.

For those of you who claim you can “change it at will”, do you feel the same effect when looking at other spinning images?

:dubious:

It is a small GIF file. Save it to your hardrive and open it up. A Gif format won’t include a random reversal. It is an interesting illusion. I see in clockwise, except for once, I got it to reverse by closing one eye at a time.

Jim

[Aholibah]

I think it would be really interesting to see results of PET scans as people looked at this animation and worked at switching from one direction to the other. As I said earlier, I default to CW. I have to look off to the side and keep her in my peripheral vision and concentrate on making her go CCW, then look back when I’ve got her spinning that way. Then to go back CW, I still have to look off to the side but it takes a lot less effort to perceive her as switching back to CW.

Anyway, in the absence of PET scan results, I don’t see how we can conclude anything about brain hemisphere action as it relates to people’s perception of this animation.

[jovan]

I found it.

The original form of this illusion is called the Sinsteden windmill:

Some illusions are caused by ambiguity in the scene. In 1860, Sinsteden noticed a remarkable thing about a windmill seen in silhouette towards the darkening evening sky of the west. This view is represented to the left. It is unclear whether the axis of the sails is directed away from you or towards you. The direction of rotation of the sails depends on which is the case. Sinsteden and I can, by a conscious effort, imagine the scene in whichever way we choose, and if we switch views, the direction of rotation reverses!

The page linked has an animated gif of the windmill. The dancer is just a perkier version of the same illusion. The windmill has no nipples that I can see.

Now about the claim of left/right brain. I found this tantalizing sentence from a 1945 paper:

Interest in reversal of perspectives in such figures as the Necker-Wheatstone cube and the Sinsteden windmill typified by the studies of McDougall, Fredericksen and Guilford, Hunt and Guilford, and George, has centered chiefly on the influence of personality differences upon the rate of reversal.

(My emphasis)

Unfortunately, I can’t get the references for this paper, but looking at publications by those mentioned, I find:
Personality Traits and Fluctuations of the Outline Cube

McDougall has suggested that the rate of fluctuation of an ambiguous figure, such as the outline cube, might be used as an objective test if introversion-extraversion.

The notion that ambiguous figures can be used to predict personality seems to go back to at least William McDougall, that’s 100 years ago. As far as I can tell, this particular theory disappears from the litterature after the 1945 paper cited above.

@Aholibah

I think it would be really interesting to see results of PET scans as people looked at this animation and worked at switching from one direction to the other.

There’s this paper: Human brain activity during spontaneously reversing perception of ambiguous figures.

Looking at ambiguous figures results in rivalry with spontaneous alternation between two percepts. Using event-related functional magnetic resonance imaging, we localized transient human brain activity changes during perceptual reversals. Activation occurred in ventral occipital and intraparietal higher-order visual areas, deactivation in primary visual cortex and the pulvinar. Thus, without any physical stimulus changes, salient perceptual flips briefly engage widely separated specialized cortical areas, but are also associated with intermittent activity breakdown in structures putatively maintaining perceptual stability. Together, the dynamics of integrative perceptual experience are reflected in rapid spatially differentiated activity modulation within a cooperative set of neural structures.

[WhyNot]

@Throatwarbler Mangrove

Well, either I’m the one being whooshed here, or you guys need to cut back on the acid, because it’s plain as day that the picture simply switches after a set time. Just watch it for 30 seconds or so. They purposely chose an image that’s distracting(woman) and hard to focus on, and notice that you only see a silhouette, which would make the transition seamless (if you could see any other details on the model, the change from clockwise to counterclockwise would be too obvious). If you look away for a moment and the direction changed, it just means the direction changed while you were looking away.

For those of you who claim you can “change it at will”, do you feel the same effect when looking at other spinning images?

:dubious:

But I can “change it at will” NOT when the little “blip” (which is the video restarting) happens. I can let the “blip” go by CW, and two turns or three turns or five turns later switch her to CCW. Or I can let the “blip” go by and not change her direction at all. It’s nothing to do with the “blip”. It is pretty trippy.

I feel an odd pressure in my left eye when I make her go CCW - the more difficult direction for me. Totally relaxed, she goes CW.

Which means the “test” is spot on for me. When I’m mentally “relaxed,” I’m much more right brained, but I’ve trained myself to think in the left brained ways as well, but it still takes more effort.

[pulykamell]

@Throatwarbler Mangrove

Well, either I’m the one being whooshed here, or you guys need to cut back on the acid, because it’s plain as day that the picture simply switches after a set time. Just watch it for 30 seconds or so. They purposely chose an image that’s distracting(woman) and hard to focus on, and notice that you only see a silhouette, which would make the transition seamless (if you could see any other details on the model, the change from clockwise to counterclockwise would be too obvious). If you look away for a moment and the direction changed, it just means the direction changed while you were looking away.

For those of you who claim you can “change it at will”, do you feel the same effect when looking at other spinning images?

:dubious:

Dude. Like I said, watch it with a bunch of people in the same room together. They will see it going in different directions at the same time, completely shooting down your theory. It’s simply an illusion.