Why do people have hallucinations?

Illusion refers to the perceptual experience when there is no corresponding objective stimulus. So why do people hallucinate?

Hallucinations generally include visual hallucinations, auditory hallucinations, color hallucinations and olfactory hallucinations. The most common are hallucinations and auditory hallucinations!

Hallucinations are a specific state! (Generally divided into two types: one is highly concentrated, and the other is semi-awake) Psychological activities that make the brain give wrong instructions!

When the spirit is highly concentrated, the frequency of information transmission is beyond the range that the brain can bear under normal circumstances! Overloading the brain and giving out wrong instructions!

When you are half awake, your brain's ability to receive and analyze information is reduced! Will also issue the wrong command ~!

When these wrong instructions are sent to the corresponding functional areas, hallucinations will occur! For example, the brain sends wrong instructions to the visual nerve, which will produce hallucinations!

visual hallucination; Vision

There are many dazzling illusion pictures at present. These pictures are visual afterimages produced by human hallucinations:

Stare at the light bulb for more than 30 seconds and try not to move your eyes. Then look at any white area. See the glowing light bulb? This is the classic? Visual residual image? .

The visual system is more sensitive to changing stimuli. When the stimulus turns white, the cells that were originally concerned about black react more strongly than other cells, producing brighter afterimages, just like a lighted lamp.

This is a negative afterimage. Of course, positive afterimages also exist.

When light stimulation acts on visual organs, the excitement of cells does not disappear with the termination of stimulation, but can be maintained for a short time. The sensory impression left after the stimulation stops is called afterimage.

Visual afterimage can be divided into positive afterimage and negative afterimage. Positive and negative images are a kind of sensory impression with the same nature as the original stimulus. Negative afterimage is a kind of sensory impression opposite to the original stimulus. For example, the bright part becomes the dark part, and the dark part becomes the bright part. The appearance of positive and negative afterimages is due to the traces left by nerve excitement. The TV movies we watch are all applications of positive and negative images. The film is shown at a speed of 24 frames per second, and the visual residue gives us the illusion of continuous pictures. If you see a colored light stimulus, the negative afterimage is the complementary color of the original color. The duration of afterimage is affected by the intensity of stimulation, the action time, the part of retina receiving stimulation and fatigue.

the illusion of depth

Look at the picture on the left. Is the black surface up or down?

If you look at this picture a little, you will feel the depth inversion. This picture is probably the most representative of all the pictures with unclear depth, and there are many such pictures with unclear depth. This is the illusion of depth. Why is this happening? Realistic three-dimensional objects are reflected on the retina in the form of planes. The visual system forcibly perceives a plane figure as a three-dimensional figure. However, on the retina, different three-dimensional objects may have the same plane image. At this time, the visual system will perceive the plane figure as one of the three-dimensional figures, but it may also perceive it as another. At the same time, your brain can only feel one image at a time, but it is impossible to feel two images at the same time. What does it matter? Fuzzy perception? Similar.

Black forest figures

The black line seems to bend outward?

The analytic black line is completely straight and parallel. This classic illusion was created by German psychologist ewald in19th century. The black forest was first discovered.

Trapezoidal hallucination

Which line looks longer, the red line or the blue line?

The analytical red line is slightly longer than the blue line, although they are exactly the same length. Less than 90? The angle of makes the edge containing it look shorter, but it is greater than 90? This angle makes the side containing it look longer. This is the trapezoidal illusion.

chessboard

Analysis: The chessboard is completely flat. This chessboard is based on Swedish artist Oscar? Based on the design of Reuters Sward, Bruno? Western creation.