Sensory phenomena in life

1, sensitivity and sensory threshold

Sensitivity is the sensory ability of sensory organs to suitable stimuli, which can also be said to be sensory sensitivity. Sensitivity is measured by sensory threshold. Sensory threshold refers to the amount of stimulus that can cause sensation in a certain period of time. Sensitivity can be divided into absolute sensitivity and differential sensitivity, which are measured by absolute sensory threshold and differential sensory threshold respectively.

Absolute sensitivity and absolute sensory threshold. Feeling is caused by stimuli, but not all stimuli can cause people to feel. In addition to the appropriateness of the stimulus, the stimulus must also reach an appropriate limit. For example, under normal circumstances, we can't feel the dust falling on our skin, and we can't hear the ticking of watches worn on our wrists. To feel, the stimulus must reach a certain amount. The minimum stimulus that just causes sensation is called absolute sensory threshold, and the ability to feel this minimum stimulus is called absolute sensitivity. Absolute sensory threshold is inversely proportional to absolute sensitivity, that is, the smaller the absolute sensory threshold, the higher the sensitivity and the lower the sensitivity. For example, if a person can hear a voice half weaker than others, then his hearing threshold is half smaller than others, and his absolute sensitivity is twice as high as others.

Differential sensitivity and differential sensory threshold. Although the stimulus intensity changes again after the stimulus causes the sensation, not all the changes in the stimulus intensity can be detected by us. If 1g is added to the original weight of 100g, the change is generally imperceptible. Only by adding more than 3g can we detect the difference in weight between them. The smallest change of stimulus that can just cause differential sensation is called differential sensation threshold, and the sensory ability that can just detect the smallest difference is called differential sensitivity. Discrimination sensitivity and discrimination sensory threshold are also inversely proportional.

The study of sensitivity and sensory threshold is of great significance to education. If teachers can understand and master students' sensitivity level and its development and change law, it will play a positive role in organizing classroom teaching, teaching students in accordance with their aptitude and career guidance.

2, the adaptation of feeling

The phenomenon that sensitivity changes due to the continuous effect of stimulation on sensory organs is called adaptation. Adaptation can not only increase sensitivity, but also decrease sensitivity. In daily life, sensory adaptation is very common, especially visual adaptation. For example, if you walk from a sunny street to a dark cinema during the day, you can't see anything at first, and then you can gradually recognize the outlines of the passages and chairs. This is an adaptation to weak light, called "dark adaptation", which is the continuous effect of weak light on improving your sensory ability; On the other hand, when you go to the cinema in out of the dark, the strong sunlight almost makes people blind, and it takes a while to feel dizzy. This is an adaptation to strong light, which is called "bright adaptation". It is the continuous action of strong light that causes the decline of visual sensitivity (bright adaptation). "Into Lan Zhi's room, I haven't heard its fragrance for a long time; The boss who enters abalone can't smell its odor for a long time, which is a phenomenon of olfactory adaptation. " "Looking for glasses with glasses" is a tactile adaptation phenomenon. As a result of continuous tasting, the dishes cooked later will become more and more salty, which is a phenomenon of taste adaptation.

It is generally difficult to adapt to hearing, but pain can't adapt at all or it is difficult to adapt, because pain is a harmful stimulus signal, and if it is too easy to adapt, it will endanger the survival of organisms.

Adaptability is formed in the long-term evolution of organisms, which is of positive significance for us to perceive external things and regulate our own behavior.

3. Feeling contrast

Contrast is a phenomenon that the same receptor receives different stimuli, thus changing its sensitivity. There are two kinds of sensory contrast: simultaneous contrast and subsequent contrast.

Simultaneous contrast is a phenomenon that several stimuli act on the same receptor at the same time, thus changing the sensitivity. For example, the same gray rectangle appears darker on a white background and brighter on a black background. If you change the background to red and green, the gray on the red background will be slightly green and the gray on the green background will be slightly red. Continuous contrast is a phenomenon that the sensitivity changes when several stimuli act on the same receptor continuously. For example, if you eat sugar and then eat an apple, you will feel malic acid. If you eat an apple and then eat sugar, you will feel that sugar is sweeter.

It is more meaningful to study the phenomenon of contrast. The color design of machinery, equipment and process pipelines in industrial production should consider the phenomenon of sensory contrast. Make full use of sensory contrast in intuitive teaching to improve teaching effect.

4. Sensory interaction

Sensory interaction is the phenomenon that the sensitivity to stimulation changes because other sensory organs are stimulated. Under certain conditions, different senses can interact with each other, thus changing sensitivity. For example, the squeak when scraping glass with a knife will make many people's skin feel cold; Weak light stimulation can improve auditory sensitivity, while strong light stimulation can reduce auditory sensitivity and so on.

5. Common feelings

Synaesthesia is a psychological phenomenon in which one feeling has another feeling. The most common phenomenon is the sense of temperature caused by color vision (color contrast-cold and warm contrast). Such as red, orange, yellow and other colors are easy to cause people's warmth, so they are called warm colors; Colors such as blue, cyan and purple are easy to make people feel cold, so they are called cool colors. Red, orange and yellow often make people feel close, which is called entering color; Blue, cyan and purple often give people a deep feeling, which is called fading. The depth of color can also cause a feeling of lightness and heaviness. Black and white balls of the same size and texture, the white one will make people feel light, and the black one will make people feel heavy. In addition, different tones will also cause different psychological effects. For example, red makes people excited, blue makes people calm and black makes people feel dignified. Synaesthesia has important application value in daily life.

First, sensory adaptation

The phenomenon that sensitivity changes under the continuous action of external stimuli is called sensory adaptation.

For example, I stayed in Lan Zhi's room for a long time and didn't smell its fragrance-olfactory adaptation.

Hands in warm water will feel hot at first, but then they will not be hot. -Adapt to skin feeling.

From bright environment to dark environment, or from dark environment to bright environment-visual adaptation.

PS: Dark adaptation takes a long time, usually 30-40 minutes. Red light can protect dark adaptation, so photographers had better wear red glasses in darkroom.

Second, feel the afterimage.

The sensory image that can be retained for a period of time after the external stimulus stops is called sensory afterimage.

For example, I walked around the beam for three days-listening to the afterimage.

Looking at the light bulb for a period of time, suddenly turning off the light will appear an image-visual afterimage.

PS: If the image you see is the same as before, it is the positive image; If the image you see at this time is contrary to the previous one, it is a negative afterimage.

Third, feeling contrast

The phenomenon that different stimuli act on the same sensory organ and change its sensitivity is called sensory contrast.

For example, red flowers are also lined with green leaves-visual contrast.

When eating Rhizoma Coptidis first and then eating honey, honey is sweeter-taste comparison.

Compared with the room temperature of air conditioner, it feels hotter outside.

Fourth, synaesthesia

The phenomenon that a stimulus not only causes one feeling, but also causes another feeling is called synaesthesia.

I feel warm when I see red, and cold when I see blue.

The lights in the ballroom are influenced by the rhythm of music.