Why there is an illusion of a hole in the palm. Binocular vision illusion. Diagonal lines are equal

Place one end of the rolled paper tube against the right eye. Place your left hand on the other end of the tube so that the tube rests between your thumb and forefinger. Both eyes are open and must look into the distance. If the images obtained in the right and left eyes fall on the corresponding areas of the cerebral cortex, an illusion will arise - a "hole in the palm".

Eye accommodation

Preliminary explanations.

Accommodation is understood as the ability of the eye to clearly see objects at different distances. Accommodation is based on the ability of the eye to change the refractive power of the optical system by changing the curvature of the lens.

Through thin gauze stretched over a wooden frame, look at the printed text about 50 cm from your eyes. If you fix your gaze on the letters, then the gauze threads become difficult to see. If you fix your gaze on the threads of gauze, then it is impossible to clearly see the text, the letters are constantly blurring. Therefore, it is impossible to see both the grid and the letter equally clearly.

Revealing a blind spot on the retina

Preliminary explanations.

The area of ​​the retina where the fibers that form the optic nerve converge is called the blind spot. When the rays hit the blind spot, the image does not appear as a result of the absence of light-sensitive elements in this area. Normally, the area of ​​the blind spot ranges from 2.5 to 6 mm2.

Place a previously prepared drawing in front of your eyes. Covering your left eye with your left eye and holding the card in outstretched right hand, slowly bring it closer to your open right eye. Fix your gaze on the left image (cross). At a distance of 20 - 25 cm from the eye, the right image (circle) will disappear. This is evidence of the presence of a blind spot on the retina.

Then the experiment is repeated, in this case you close your right eye and fix the right image on the card with your left eye.

Determination of hearing acuity.

Place a mechanical watch to your ear and keep it away from you until you can no longer hear it ticking. At the moment the sound disappears, measure the distance (in cm) between the watch and your ear. The larger it is, the better the hearing sensitivity. Now bring the watch closer to your ear from afar until a subtle sound appears. Measure the distance as well. Calculate the average. So find your auditory sensitivity

Revealing the sensitivity of the tongue to various stimuli

On different parts of the tongue, alternately apply drops of solutions of quinine, sugar, sodium chloride and citric acid with a glass rod, determine the taste of the solution. Make a taste map of the tongue and sketch it.

TOPIC " MUSCULOSKELETAL SYSTEM"

Determination of the flexibility of the spine

1) Take a ruler in your hands and stand on a chair or rung of a ladder.

2) Without bending your legs, bend the body at the lower back.

3) Measure the distance between the index finger of the hands down and the level of the chair (ladder).

Evaluation of results: good flexibility of the spine - if the finger drops below the level of the chair by 5-10 cm.

Insufficient flexibility of the spine - the finger has reached the level of support.

Poor flexibility of the spine - the finger did not reach the level of support

Identification of posture disorders

1. Stand with your back against a wall with your head, shoulders, and buttocks touching the wall.

2. Try to stick your palm and then your fist between the waist and the wall.

Evaluation of results: posture should be considered normal, if a palm passes between the waist and the wall, the fist should not pass.

Determination of the presence of flat feet

1. It is necessary to take a sheet of wet paper and stand on it. Outline the footprint with a pencil.

2. Find the center of the heel and the center of the third toe.

3.Connect the two found points with a straight line.

Evaluation of results: if in the narrow part the trace does not go beyond the line, there is no flat feet.

Combination of static and dynamic muscle work

1. Take dumbbells, notice the time during which you can hold them in your arms spread out to the side.

2. Take a rest, and then do physical exercises with the same dumbbells. Notice how long the fatigue will come.

3. What kind of work is easier - dynamic, to move the load or static, associated with holding it?

Topic: Visual analyzer.

Target: Study of the structural features and functions of the visual analyzer.

Tasks:

1. To create conditions for understanding the value of the visual analyzer in human life and the need to comply with hygienic rules to preserve vision.

2. Create conditions for studying the structural features of the visual analyzer and identifying the relationship between the structure and the functions performed.

3. To create conditions for the formation of UUD, namely: to compare, analyze, identify cause - effect relationships, draw conclusions.

4. Create conditions for the formation of skills and abilities to work in a group.

Equipment: presentation, table "Visual analyzer", eye model, handouts.

Lesson type: combined (lesson in obtaining new knowledge)

Methods: partially - search, problematic.

Form of work: group, individual, frontal.

During the classes

Organizing time.

Motivation.

Knowledge assessment, test execution with mutual verification.

1) The accumulation of bodies of neurons forms:

a. Gray matter

b. white matter of the brain and spinal cord

2) The spinal cord performs in our body:

a. reflex function only

b. only conductive function

v. reflex and conductive functions

3) Which part of the brain does the cerebral hemispheres belong to?

a. spinal cord

b. brain

Teacher: What is part of the central nervous system? (Student responses.)

Teacher: The entire human body is permeated with nerve cells. Thanks to nerve cells, communication with the environment and the body's response to the environment are carried out. Question: What is the name of this process? (student response)

What is the name of the path along which nerve impulses pass (student's answer)

Question: Can you give examples of a reflex arc? (student response)

What are the parts of the reflex arc? (student response)

Question: How many paths have you seen? (student response)

Compare with the structure of the analyzer? (student response)

Teacher: What areas of the cerebral cortex do you remember and what are they responsible for? (1 person shows according to the table)

Teacher: You have objects on your tables (mandarin, rattle, soft toy). Collect as much information as possible about them. Using all possible senses.

Teacher: With the help of which sense organ did you receive the most information. (Student responses)

Teacher: What is the significance of the organ of vision in human life? (student response)

Question: What can disturb the functioning of the organ of vision? (student response)

Teacher: Guys, try to form the topic of today's lesson (student response)

See. analyzer

Cluster method

Structure Functions

Meaning

Students form the purpose and objectives of the lesson.

Teacher: In the course of zoology, we studied the organs of vision in various groups of animals.

Question: How did the improvement of the organs of vision go? (student response)

Teacher: So gradually nature came to a more perfect organ of vision. (students' answers)

Problematic question: Why do they say "Take care like the apple of your eye"? (students' answers)

Teacher: 90% of the information we get through this body.

Teacher: Guys, close your eyes for a few seconds.

Question: How do you feel? (student response)

Teacher: Let's find out how our eye works?

Learning a new topic.

Work in groups, students study material from the textbook.

Group 1 - eye position, auxiliary organs, functions.

Group 2 - internal and external structure of the eye, functions

Group 3 - ray path through the transparent medium of the eye.

Time is given for independent study of the material in groups. (7 minutes)

Question 1 to group: What have you learned about the position of the eye, auxiliary organs, functions? (student response) (Slide)

Question 2 to group: How is the internal structure of the eye, functions? (student response) (Slide)

Distribute cards, decipher digital symbols.

Question 3 to group: How is the path of rays through the transparent medium of the eye carried out? (student response) (Slide)

Physical exercise "Gymnastics for the eyes" (drawing a figure eight with closed eyes)

Teacher: You and I have studied all parts of the eye and functions.

Question: Why do you think the image that hits the retina is inverted? Why don't we see everything around us upside down? (students' answers)

Teacher: As a rule, analyzers give a correct idea of ​​the surrounding reality, but mistakes are possible.

Question: What are they called? (student response)

Laboratory work

"Illusion associated with binocular vision"

Purpose: to see the illusions associated with binocular vision.

Equipment: rolled paper sheet.

Progress:

Attach one end of the tube to the right eye. Place your left hand on the other end of the tube so that the tube rests between your thumb and forefinger. Both eyes are open and must look into the distance. If the images obtained in the right and left eyes fall on the corresponding areas of the cerebral cortex, an illusion arises - a “hole in the palm”.

Conclusion: If the images obtained in the right and left eyes fall on the corresponding areas of the cerebral cortex, there will be an illusion, a hole in the palm

Anchoring

Teacher: Now let's turn to the slide "Test your knowledge"

Reflection: What was interesting? (students' answers)

What was not clear, caused a difficulty? (students' answers)

What would you like to know about the visual analyzer? (students' answers)

Homework: Ex 49.

1. Review the structural features of the visual analyzer.

2. Reveal the connection between the structure and the functions performed.

3. Prepare a message “Causes that worsen the work of the organ of vision.

4. Prepare a memo for the eyes: for working with a computer. Types of eye gymnastics.

Today, optical illusions can often be found on the Internet - these are faces hidden behind other images, and photographs (as in the case of a blue or golden dress), and drawings in which you can see two different objects at once (as in the picture, where you can see rabbit and duck).

But there is an amazing illusion that you can easily arrange yourself. It is based on the features of the brain and vision. Thanks to a special technology, you can trick the brain and make it see a hole in your hand! And all this with a simple sheet of paper.

Vanessa Hill, founder of a YouTube channel called Braincraft, filmed a video tutorial of this illusion and explained why the brain works in this case in this case.

Here's a step-by-step guide:

1. Take a sheet of A4 paper and roll it into a narrow tube.

2. Place the tube with your right hand over your right eye and look through it.

3. Now bring your left palm to your left eye about 5 cm from your face.

4. Stay in this position. Keep your hand in place and look through the tube. Do not focus on your palms.

5. After about 10-15 seconds, the picture from both eyes will seem to match, and you will see a hole in the middle of your left palm.

How is it? Did you manage to achieve this unusual optical illusion?

Vanessa explained the mechanism of what is happening. Our eyes see two different pictures. Since the brain cannot combine two images, one of them displaces the other. As a result, the picture that one eye sees becomes dominant. This phenomenon of how our brains work is called binocular (or retinal) competition.

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Optical illusions not only stress your brain, but can also be a sign of certain mental, perceptual or visual disorders. If you are deceived by these four illusions, then you are all right.

Hollow mask

Hollow mask video illusion is one of the most popular in mental illness. Observe yourself: what do you see when the mask rotates in this video?

If it seemed to you that the pink side of the mask is also convex, most likely your sanity is in order. But for people who suffer from schizophrenia, this illusion acts much less often.

Approximately 30% of patients with paranoid or undifferentiated schizophrenia, during an exacerbation, see a concave surface even after turning the mask. Among healthy people, the illusion does not work about 10% of the time. Also, a low susceptibility to this illusion can be a sign of proximity to psychosis.

Experts attribute this to a disorder of volitional attention, which develops in patients with schizophrenia due to dysfunction of the prefrontal cortex. For those who have successfully undergone treatment for schizophrenia, the illusion of the "hollow mask" begins to operate again.

Dot Cylinder

Take a close look at this video. This is a rotating cylinder. It is in your power to "switch" its front side - you can "put" only white or only black dots in front. Try to "switch" several times.

Do you see the black "side" of the cylinder when you focus on the white? Most people's answer is yes. But volunteers with a high "autism rate" focus on only one color and literally stop seeing the other "side", this can be tracked by the size of their pupils. Scientists seriously suggest using this illusion as a rapid diagnostic test.

It is known that people with autism spectrum disorders find it easier to see the details rather than the big picture. However, scientists still do not fully understand the mechanisms of this. Perhaps this is due to the peculiarities of the transmission of sensory signals or the inability to switch or divide attention to several objects.

Oblique lines

Before you are six rows of figures - three blocks of two rows. Look closely: are these pairs of rows narrowing or widening?

Image: Ariella V. Popple / pnas.org

People with normal vision answer that the pairs of rows converge to the right edge of the picture. But people with amblyopia - a disease also called "lazy eye" - can see both narrowing of the rows, and their expansion. In reality, the rows are parallel to each other.

"A hole in the palm"

Another illusion that can indicate vision problems. It cannot be filmed, you can only see it with your own eyes. You will need a piece of paper rolled up into a tube (a notebook or newspaper will also work).

Place the tube over your right eye and look into the distance. Place your left hand on the far end of the tube on the left side.

In people with binocular - normal - vision, a "hole" will be visible in the middle of the palm, and many other objects will be visible through it. This is due to the fact that the picture, seen through the opening of the tube, is superimposed on the image of the palm in the other eye.

With simultaneous vision - when both eyes see, but the images do not merge into one visual image - the "hole" will not coincide with the center of the palm. With monocular vision - when only the right or left eye sees - the phenomenon of a "hole" in the palm does not appear at all.

Remember that the diagnosis can only be made by a qualified specialist after a sufficiently long observation. If you feel unwell or in doubt about your health, seek medical help.

Recently, a new optical illusion has appeared on the Internet, which depicts blurry colored spots on a white background. The author of the picture stated that if you start to peer into the image for about a minute, then only a white background will remain in front of the viewer.

Scientists attribute this optical illusion to the Troxler effect. Its essence lies in the fact that the human brain is able to ignore the signals of the receptors if the gaze is focused on any object for a long time. That is, when peripheral details are blurred, they eventually disappear.

A person can observe the same effect, for example, when putting on underwear in the morning. The first few seconds he feels the presence of clothes, but soon his sensory neurons adapt, and the feeling of the presence of cowards disappears.

Impressed by the peculiarities of human perception, we decided not to dwell on one optical illusion and compile a selection of images that can break your brain.

Smooth floor

That's right, this is an absolutely flat floor. The unusual surface was developed by the British company Casa Ceramica, and the optical illusion only works if you look at the floor from a certain point.

Same size of railroad parts

As wild as it may seem, these two parts of the toy railroad are equal. However, the part on the left appears to be noticeably larger than the part on the right. Optical illusion is called the Jastrow effect after the American psychologist Joseph Jastrow. He explained back in the 19th century that two curved shapes would appear different when aligned along the edge. Due to the fact that the top of the part is slightly longer than the bottom, it seems that the size of the parts is different.

The video clearly demonstrates how this illusion works.

Does the cat go down or go up?

A photo of an innocent cat went viral back in 2015, with netizens wondering if a cat is coming up or down.

Trying to find the answer to the question, they resorted to all possible spheres of human knowledge - from biology to architecture. After extensive research, the Internet community has come to the conclusion that the cat is going down the stairs, not up them.

Strange photo of a couple hugging

The image of two people hugging went viral after a Reddit user posted it with the caption, "It broke my brain ..."

People could not understand what was happening in the photo and who was the owner of whose legs until the solution was found. The fact is that the black guy has black shorts on the sides, and white in the middle, which creates a huge dissonance in the perception of what is happening.

Diagonal lines are equal

You are probably 100 percent sure that these diagonal lines are of different lengths. Another brain-bearing illusion that allows you to think so is called Zander's parallelogram. In fact, the diagonal lines are equal.

By CountingPine

Cells A and B are the same color

This illusion is called "the illusion of Adelson's shadow," and it is directly related to the perception of our past. The fact is that a lighter cell surrounded by dark ones will appear whiter and vice versa. Our eyes are also used to ignoring gradual changes in light levels. Therefore, it seems to us that cells A and B are different colors, but this is actually not the case.

By Edward H. Adelson

The proof that the colors of the cells are the same is clearly demonstrated in this video.

Is the girl underwater?

In the photo it may seem that the girl is under water, but that was not the case. As many netizens have noticed, her hair is dry and does not float, and the "air bubbles" are just well-captured drops of water.

Giant hole in hand

The person's hand in this photo looks like it contains an endless abyss. The illusion is created by gradually decreasing the rectangles inside the spiral.