[dustin_archibald]

While sitting outside the local butcher shop, I was staring at the Christmas lights they had around the window. They had them flashing in way that the lights seemed to be moving in one direction; clockwise (I'm sure you see that all the time). As an exercise I dedicated my time there to making the lights move in the opposite direction. It was hard to do at first, but now I can look at them and make them go in either direction.

I don't know if everyone can do that naturally or not...

[zeroca]

This is the matter of perception. As I mentioned before, reading isn’t my favorite method; I rarely read scientists’ theories, because I think that developing intellectually they blunt the intuition, but after I moderate sub-forum – biology/psychology, I got the book at once: brief course in psychology. To say the truth, I’ve never studied it, but as medicine anyway is close to this sphere, everything seems very interesting to me. I only slightly looked at part – perception and as if a coincidence read your thread.

I created an animation. I part is developed by me, but the II, and III parts – taken from the course of psychology.

The technique was following: Each entire cycle of animation (one entire turn of each spinning wheel) consists of 20 frames: phases of the starting and ending frames differ from each-other and ciphers show lagging, i.e. different angle between them (each ending phase is turned clockwise at mentioned angle towards the starting one, but starting one is the same for every wheel=stopped wheel). Each cycle afterwards is repeating permanently (to make a permanent picture of revolving), and the option of revolving - clockwise is given to each one, i.e. all wheels are turning clockwise. Enjoy it! And please, concentrate on the variant, when legging equals to 270 degrees, but explanation will be given as soon as I read the part – perception.

In the II and III examples intervals a and b are of the same length.

[mkirkpatrick]

Zeroca, how on earth do you manage to do these wonderful drawings,

I would really like to be able to present stuff like that!

Kind regards, Michael.

[zeroca]

Dear Michael!
Thanks for your high opinion about my drawings.
Here’s a new animation: Almost the same one, but difference is that two opposite segments (we can count it one segment) is made red, and I forgot to mention, that speed in both: previous and present one is - 12 frames/sec. This animation was made in order to show visually that all wheels spin clockwise. Anyone can notice shift (jump) from final phase to the starting one, when the ended thorough cycle is beginning anew; it happens because of lagging (the ending phase is turned clockwise at shown angle to starting one), but it doesn’t matter in our particular case.

Please, compare two animations: from previous and present post.
Everyone is welcomed to express his analysis on this matter. I.e. to explain, why visual effect is, as if some wheels spin counterclockwise. Please be as accurate, brief and close to the subject as can. Your opinions will be counted of high value.

The nether two ranges are final, ending phases of cycle, shown for demonstrative purposes.
Regards,
zeroca.

P.s. I'd like to add, that variant, when lagging equals to 360, is the same as when it equals 0.

[zeroca]

Let’s proceed with explanations:

Reading of the part of “brief course of psychology” – perception didn’t give me the explanation of considered by us test above (the truth, it gave a lot of interesting explanations of some other phenomena). Anyway, I took first four successive phases of animations (when lagging equals to 0 degrees–I picture, and when the lagging equals to 135 degrees - II picture) and overdrew mentioned four phases for both cases. You can read on the animation the colors of each successive phase: 1.blue, 2.black, 3.red and 4.green;
(There are 16 spokes in all within each wheel).
You see clearly that in I picture (see separate sector below) the next position! of first blue spoke is marked as black; red spoke is the position of 16-th spoke (the second phase of spinning), its following - green is the position of 15-th spoke (third phase of spinning), i.e. each following position of previous spoke is close to the starting position of next spoke from the left side (in each following position).

As for the II picture, each following position of first blue spoke is disposed close to the position of the second blue spoke (each spoke from previous position takes the next position close to the former position of the next spoke) from the right side (In each following position).
I.e. eye constructed the way that “it prefers” to perceive closer next disposition - shifting to closer distance despite direction of spinning! I.e. motion is perceived by eye as sum of shiftings between closest distances of spokes’ positions.
I see that this isn’t perfect explanation, but let’s continue deeper analysis in following posts.

[zeroca]

At the same time I offer a little test for eye. An animation below is the modification of the test from the course of psychology. Enjoy it! Explanation will be given in the following post.

Cover your left eye with hand or simply close it. Concentrate with opened right eye on the bigger black ball, not diverting the attention from it. Simultaneously watch the movement of the small ball with “complementary field of vision”. Keep distance of approximately 30cm from the screen. You notice that at some distance small black ball disappears and in a while it appears anew.

P.s. You can conduct a test otherwise: with closed right, and opened left eye, but in this case with opened left eye you should concentrate on moving (smaller) ball, observing with “additional field of vision” the bigger black ball. You see clearly, that in a while bigger black ball disappears, and then appears anew in the field of vision.

[mkirkpatrick]

Originally Posted by zeroca At the same time I offer a little test for eye. An animation below is the modification of the test from the course of psychology. Enjoy it! Explanation will be given in the following post. Cover your left eye with hand or simply close it. Concentrate with opened right eye on the bigger black ball, not diverting the attention from it. Simultaneously watch the movement of the small ball with “complementary field of vision”. Keep distance of approximately 30cm from the screen. You notice that at some distance small black ball disappears and in a while it appears anew. P.s. You can conduct a test otherwise: with closed right, and opened left eye, but in this case with opened left eye you should concentrate on moving (smaller) ball, observing with “additional field of vision” the bigger black ball. You see clearly, that in a while bigger black ball disappears, and then appears anew in the field of vision.

Yes it does work! How on earth do you work all this out,keep up this interesting work.
kind regards michael.

[harmonygirl]

REALLY COOL! Where they disappear, is this where your nose interferes with the field of vision?

[zeroca]

Originally Posted by harmonygirl REALLY COOL! Where they disappear, is this where your nose interferes with the field of vision?

I don't know as for anybody else's nose, but as for my nose, you guessed: it’s really great!!! Even some people instead of shaking my hand shake my nose by mistake, but as for test, as you noticed, a nose remains on the side of closed eye, so it “isn’t to blame” for it.

I read the part of psychology – perception, trying to find out the answer for the phenomenon, mentioned in dustin archibald’s post, but in spite of the fact that the author of this book is one of the best psychologist - Revaz Natadze, I couldn’t find the explanation, so I will have to offer my solution about it, but I’ve almost forgotten the construction (anatomy and physiology of eye).
But when reading the part – vision and its sensitivity, I reread and remembered the anatomy of the retina: there are two different kinds of receptors on it – rod cell and cone cell (of retina) but the place on the retina, where the optic nerve (nervus opticus) comes out, is deprived of receptors, so this point is never irritated by light, so is called “a blind point” and the part of picture, which falls on this “blind point” isn’t perceived.
The diameter of the “blind point” is 1.8 mm, but it makes an angle of 6 degrees in the field of vision. When looking binocularly (with both eyes), this defect of vision isn’t detected by person, because the field of vision of the second eye covers it. Even with closed one and moving second eye this defect of vision isn’t detected, because “blind point” is moving, and part of the picture, fallen on it also is moving to another part of retina, i.e. this point is detectable only with closed one and fixed another eye. I found this test in this book and offered my modification - animation about it, so I took it from the book and didn’t work it out…

[zeroca]

When reading the brief course of psychology (part - attention), I came across one interesting experiment: as it appears, the individual doesn’t perceive by vision everything that’s in the field of vision (for instance, if we are looking at the blackboard with 20 different numbers written on it, we don’t perceive simultaneously all, but only part of them) despite impressing of all of them on the retina. What’s the reason? i.e. why all numbers aren’t perceived despite them being within the field of vision? It was told in the conclusion that volume of attention is restricted (defined).

As experiment revealed, volume of attention usually equals to 5-6 simple impressions. When in the device, called tacho-scope, the persons were shown huge amount of black points with the speed of one/tenth, or one/fourth of second, the persons couldn’t perceive more than six ones at the time. (The number of shown simultaneously perceived objects lessens to five, if instead of black points small pictures of numbers are displayed)
As a conclusion, the person generally can’t perceive all material that’s impressed on the retina. The question, why, isn’t answered yet, at least I didn’t find what is material substrate, ground for such perception in detail.
I offer a simple animation, as test for readers:
You should concentrate on red point within the circle and test, how many numbers or letters you can read at the same time. I can 4-5 including red point.
The technique of animation: there are 40 frames in animation and speed is 4 frames/sec, i.e. the time of appearance of one frame is one fourth part of second. Numbers and red point are placed within the same one frame.