General law of feeling
Feeling is a subjective image of the objective world, and any feeling must meet two conditions: first, the subject's sensory ability; The other is the stimulation of the objective world. The former is a sensitive issue; The latter is a matter of sensory threshold.
1. Sensitivity and sensory threshold
(1) sensitivity
Sensitivity: it is the sensory ability of sensory organs to suitable stimuli. That is, people's sensitivity to stimuli.
Absolute sensitivity: the ability to feel the minimum amount of stimulus.
Differential sensitivity: The ability to detect the smallest difference between two stimuli of the same kind is called differential sensitivity.
(2) Sensory threshold
Sensitivity is measured by sensory threshold. Sensory threshold refers to the stimulus range that can cause people to feel.
Absolute sensory threshold: the minimum amount of stimulus that can cause sensation.
Differential sensory threshold: also known as just-detectable difference, also known as minimum-detectable difference, refers to the minimum change that can cause the stimulus of just-detectable differential sensory. It is the smallest difference that distinguishes different stimuli.
For example, a glass of water can't feel sweet when adding 100 g of sugar at first, but it can feel sweet when adding 300 g; Then add it to 300 grams to feel the sweetness, which is absolutely sensitive; The taste difference between100g and 300g can be detected, which shows the discrimination sensitivity. The minimum amount of 300 grams that causes taste bud stimulation is the absolute sensory threshold; Then the amount between 100 and 300 grams is the differential sensory threshold.
Sensitivity is inversely proportional to the sensory threshold, and the greater the sensory threshold, the worse the sensory ability.
2. The law of sensitivity change (sensory phenomenon)
(1) sensory adaptation
Sensory adaptation is a phenomenon that the sensitivity changes because the stimulus continues to act on the same receptor. Sensory adaptation can either increase or decrease sensitivity. Under normal circumstances, continuous strong stimulation reduces sensitivity; Continuous weak stimulation will increase sensitivity.
Visual adaptation can be divided into dark adaptation and light adaptation.
① dark adaptation: from bright environment to dark environment, you can't see things at first, and then you can see things gradually. This is called dark adaptation. Dark adaptation is a process of improving sensitivity when light stimulation changes from strong to weak.
(2) From the dark environment to the bright environment, I began to feel that the light stung my eyes and soon got used to it. This is called bright adaptation. Photoadaptation is a process in which the sensitivity decreases when the light stimulus changes from weak to strong.
Olfactory adaptation: Entering Lan Zhi's room for a long time without smelling its fragrance? This is olfactory adaptation.
Adaptation of skin sensation: When swimming, you will feel that the water is very cold when you just jump into the water, and this feeling will soon disappear. This is the adaptation of skin feeling. When you put your hand in warm water, you start to feel hot, and then you don't feel hot. This is the adaptation of temperature perception.
In addition, there are adaptations to hearing and taste. All kinds of feelings can be adapted, and the adaptation phenomenon is manifested in all kinds of feelings, among which pain is the most difficult to adapt, because pain has a protective effect.
(2) Feeling contrast
Sensory contrast: the phenomenon that different stimuli act on the same sensory organ and change its sensitivity is called sensory contrast. There are two kinds of sensory contrast: simultaneous contrast and subsequent contrast.
① Simultaneous contrast: refers to the change of sensitivity to a stimulus caused by several stimuli acting on the same receptor at the same time.
For example:? A little red in the evergreen tree? 、? Stand out from the crowd? 、? Is the moon star rare? . Another example is the French novelist Zola's novel "The Hall", which describes some rich ladies and wives, finds some ugly people with no characteristics, and often carries them around to show their beauty in public places. Another example: "Tang Bohu ordered autumn fragrance"? Chou-heung also smiled? It also takes advantage of the contrast effect.
② Successive contrast: refers to the change of sensitivity to a stimulus caused by several stimuli acting on the same receptor one after another. For example, if you take medicine after eating sugar, you will feel that the medicine is particularly bitter. If you eat sugar after eating, you will feel that sugar is particularly sweet. ? Bitter first, then sweet? . Coming out of cold water and then into slightly hotter water, I feel that hot water is hotter.
(3) Sensory aftereffect
The sensory phenomenon that remains temporarily after the stimulation stops is called sensory aftereffect, which is also called sensory afterimage. (4) Compensation and interaction of sensation.
① Compensation function of senses: When some senses are lost, other senses can be used to compensate.
For example, blind people have better hearing than normal people.
2 Sensory Interaction Synaesthesia: The phenomenon that a stimulus not only causes one feeling, but also causes another feeling is called synaesthesia.
For example, red looks warm and blue looks cool; When listening to music with clear rhythm, I feel the lights flashing like the rhythm of music. A Bing, a blind man, reflected the moon in the eyes of two springs, which was very sad.
Test practice
The longer the chef cooks, the heavier the salty taste, which reflects the law of sensitivity change ().
A. Feeling contrast
B. Sensory aftereffect
C. sensory compensation
D. sensory adaptation
The answer is D. The saltier the chef's cooking, the more it reflects the sensory adaptation, so the answer is D.
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