第8讲 认知的第一步—感觉及其规律在线视频

好 同学们 从现在开始
Well, every one, from now on

我们就要讲述各种具体的心理现象了
we will talk about various specific mental phenomena

今天我们要讲的是感觉现象
Today we are talking about sensation phenomena

什么是感觉呢
What is sensation?

在日常生活中 我们可能会说
In daily life we might say

“今天我感觉不错”
"I sense good today!"

其实指的是
Actually, we mean that

我们有一种愉快的心境状态
we have a happy state of mind

有时候我们说
sometimes we say

“我对他没感觉”
"I don't sense anything about him!"

意思是 我不喜欢他
meaning that I don't like him

那么这些说法
Well, these statements

其实都是一些日常概念
are actually some everyday concepts

而我们心理学所讲的感觉
and sensation in psychology

是一个科学概念
is a scientific concept

它指的是一种认识事物的过程
referring to a process of understanding things

感觉就是人脑对直接作用于感官系统的
Sensation is the reflection of the human brain on the single attribute

客观事物的单一属性的反映
of objective things directly acting on the sensory system

任何一种动物都通过独特的感官系统
Any animal obtains information from the outside world

从外界获取信息
through a unique sensory system

那么我们人类的感官系统有哪些呢
So What sensory systems do we humans have?

在漫长的历史演化过程中
In the long evolutionary process

我们人类形成了视觉 听觉
humans have formed five sensory systems of vision, hearing

嗅觉 味觉和肤觉这五大感官系统
smell, taste and skin

外部的刺激作用于我们的感官系统
When external stimuli act on our sensory system

我们就会产生视觉 听觉
we will produce sense of vision, hearing

嗅觉 味觉和肤觉等相应的感觉
smell, taste and skin

比如 我们面前有一个苹果
For example, there is an apple in front of us

我们用眼睛去看
We see it with our eyes

苹果表面反射的一定波长的光
The light of a certain wavelength reflected on

作用于我们的视觉系统
the surface of the apple acts on our visual system

我们就看到它是红色的
and we see that it is red

我们用鼻子闻一下
We smell it with our nose

苹果散发的气体物质
The gaseous substance emitted by the apple

作用于我们鼻腔上部
acts the olfactory cells in the mucous membrane

黏膜中的嗅细胞
of the upper part of our nasal cavity

我们就知道它是香的
we know that it is very fragrant

我们用嘴一咬
When we bite with our mouth

苹果内部的化学物质
the chemicals inside the apple

作用于我们舌面的味蕾
act on the taste buds of our tongue

我们就知道它是甜的
we know that it is sweet

拿在手上掂一下苹果会压迫我们的皮肤表面
Apple presses the surface of our skin

我们就知道它有一定的重量
we know that it has a certain weight

我们通过感觉系统
Through the sensory system

就可以获得事物多个方面的信息
we can obtain information on many aspects of things

这就使我们有可能对这些信息
which makes it possible for us to process this information

进行更高水平的加工
at a higher level

同时还保证了我们
while also ensuring the balance of our information

与环境的信息平衡
with the environment

当刺激作用于我们的感官
When stimuli act on our sensory organs

我们就产生感觉
we produce sensations

那么刺激与我们的感觉之间
So what is the relationship

是什么关系呢
between stimuli and our sensations?

从直观上来看
Intuitively

刺激的强度跟我们的感觉
the intensity of the stimulus with our sensations

具有直接的因果关系和比例
has a direct causal and proportional relationship

也就是说 如果一个刺激越强
that is, the stronger a stimulus

我们的感觉就会越强烈
the stronger our sensation

比如 水的温度越高
For example, the higher the temperature of water

我们就感觉越热
the hotter we feel

但是仔细体会
But if you experience it carefully

你会发现
you will find that

刺激和感觉的关系
the relationship between stimulus and sensation

并不是那么直接
is not so direct

比如
For example

当我们刚把手伸进凉水的时候
when we just reach into the cold water

觉得水很凉
we feel that the water is very cold

过了一会就觉得没有那么凉了
After a while, we feel that it is not that cold

我们刚从黑暗的地方
When we come to the sun from the dark place

到太阳底下的时候会觉得阳光很刺眼
we just feel that the sun is dazzling

但是过了一会 就没有那么刺眼了
but after a while, it is less dazzling

我们中国古代有一个说法
In ancient China, there was a saying

叫做 入芝兰之室
When you enter the room with vanilla and orchid

久而不闻其香
you will not smell the fragrance after a long time

入鲍鱼之肆
when you enter the salted fish shop

久而不闻其臭
you will not smell bad after a long time

他的意思是说
That is to say

房间里有芝和兰这两种有香气的植物 房间里就闻着很香
the plant smelled very fragrant in the room

但进去待一会以后
but after some time

就觉着没有那么香了
it smelled less fragrant

进入卖咸鱼的店
Entering the store selling salted fish

闻着很臭
it smells stinky

但在里面待了一段时间以后
but after a while

就闻着没有那么臭了
it smells less stinky

所以
Therefore

其实客观刺激
although objective stimuli

和我们的主观感觉虽然有关系
and subjective sensation are related

但它们是不同的现象 是两码事
they are different phenomena and two different things

早期的心理学很喜欢研究
Early psychology liked to study

物理刺激和心理感受之间关系
the relationship between physical stimuli and mental feelings

这在当时叫心理物理学
which was called psychophysics at the time

是德国的物理学家
which was proposed by the German physicist

古斯塔夫·费希纳提出来的
Gustav Fechner

关于心理物理学
With regard to psychophysics

一个基本的问题是
a basic question is

是不是任何刺激
can we notice all the stimuli

作用于我们的感官我们都能感受到呢
acting on our sense organs?

比如
For example

无论多么微弱的光我们都能看到吗
can we see the light no matter how weak it is?

无论多轻的物体
Can we notice all the stimuli

落到我们皮肤上我们都能感受到吗
that fall on our skin no matter how light it is?

显然不是
Obviously not

每时每刻
Every moment

都会有灰尘落到我们的皮肤上面
dust will fall on our skin

我们却感受不到
but we can't notice it

因为刺激太微弱了
because the stimulus is too weak

那么多么强烈的刺激我们才会感受到呢
So how strong is the stimulus that we will notice?

心理学家把人感觉到
Psychologists call the critical value of the amount

某个刺激的存在所需的量的临界值
a person required to notice the presence of a certain stimulus

刚刚能引起感觉的最小刺激量
the minimum amount of stimulus that can just cause sensation

叫做绝对感觉阈限
the absolute sensory threshold

人的感官能够觉察刚刚能引起
And the ability of a person's sensory organs notice

感觉的最小刺激量的能力
the smallest amount of stimulus that has just caused a sensation

叫做绝对感受性
is called absolute sensibility

那么 这两个概念是什么关系
What is the relationship between these two concepts?

其实绝对感受性
In fact, absolute sensibility is defined by

是用绝对感觉阈限来界定的
the absolute sensory threshold

绝对感觉阈限越大
The larger the absolute sensory threshold

也就是引起感觉
that is, the greater the minimum amount of stimulus

所需要的最小刺激量越大
required to cause sensation

我们的感受性就越小
the lower the absolute sensibility

相反 绝对感觉阈限越小
Conversely, the smaller the absolute sensory threshold

也就是能引起
that is, the smaller the minimum amount of stimulus

感觉所需要的最小刺激量越小
required to cause sensation

那么感受性就越大
the greater the sensitivity

他们两个是反比关系
The two are inversely related

心理学家发现

不同的感觉系统 不同的人
Different sensory systems and different people

感觉阈限是不一样的
have different sensory thresholds

我们在附加学习材料里面
In additional learning materials

列举了五种感官的
we listed the specific data of the absolute sensory threshold

绝对感觉阈限的具体数据
of the five sensory organs

大家可以去了解一下
you can learn about them

那么 对某个具体的人来说
So, for a specific person

绝对感受性是不是永远不变呢
is absolute sensibility the same forever?

其实不是
Actually not

人的绝对感受性是会发生变化的
The absolute sensibility of a person will change

其中最常见的变化是由于刺激物的持续作用
The most common change is the change in sensibility

而使感受性发生的变化
due to the continuous action of stimulus

这种现象叫作适应
This phenomenon is called adaptation

视觉 听觉 嗅觉
Sense of vision, hearing, smell

触压觉 温度觉等等都表现出适应
touch pressure, temperature, etc. all show adaptation

其中 视觉适应分为暗适应
Among them, visual adaptation is divided into dark adaptation

和明适应两种
and bright adaptation

当我们从暗处来到光亮处
When we come to the light from the dark

我们的视觉感受性就会下降
the visual sensibility decreases

这叫明适应
which is called bright adaptation

长时间被关在暗处的人
People who are kept in the dark for a long time

一到光亮处
when they come to the bright place

觉得光线特别亮 特别刺眼
feel that the light is particularly bright and dazzling

过一会就感觉没有那么亮了
After a while, they feel less bright

也就是感受性下降了
that is, their sensibility decreases

这就是明适应
This is bright adaptation

一般来说 明适应发生的非常快
Generally, bright adaptation happens quickly

当我们从亮处来到暗处的时候
When we go to a dark place from a bright place

我们能的视觉感受性会提高
our visual sensibility will improve

这就是暗适应
which is dark adaptation

晚上休息的时候
When we go to sleep

我们刚刚关灯的时候
and turn off the lights at night

觉得房间里特别黑
we feel that the room is very dark

过了一会 就不那么黑了
After a while, it is not so dark

也就是感受性提高了
that is, the sensitivity is improved

这就是暗适应
This is dark adaptation

一般来说
Generally speaking

暗适应的时间比较长
dark adaptation takes a long time

前面提到的
As mentioned earlier

入芝兰之室
When you enter the room with vanilla and orchid

久而不闻其香
you will not smell the fragrance after a long time

入鲍鱼之肆
when you enter the salted fish shop

久而不闻其臭
you will not smell bad after a long time

其实是一种嗅觉适应
actually is a kind of olfactory adaptation

也就是 在刺激的持续作用下
that is, under the continuous action of stimulation

我们的嗅觉感受性下降了
the olfactory sensibility decreases

关于心理物理学
Regarding psychophysics

另一个基本的问题是
another basic question is

刺激的量只要发生变化
can we notice the change

我们都能感受到吗
whenever the amount of stimulus changes?

比如 重量发生变化
For example, when the weight changes

声音发生变化
the sound changes, etc

心理学家把人感到某个刺激强度变化
Psychologists call the threshold of the minimum physical difference

所需的最小物理差异的
required for a person to notice a change

临界值叫作差别阈限
in the intensity of a stimulus as the difference threshold

而人的感官刚刚能够识别出
and the ability of human notice the minimum physical

两个刺激的最小物理差异的能力
difference between two stimuli

叫差别感受性
is called difference sensitivity

物理刺激改变多少
How much do physical stimuli change

我们才能觉察到呢
before we can notice?

是不是改变的多
If the stimuli change a lot

就一定能感受到变化
you will definitely notice the change

改变的少
and if the stimuli change a little

就一定不会感受到变化呢
you will definitely not notice the change?

德国生理学家恩斯特·韦伯认为
German physiologist Ernst Weber believed that

对刺激物的差别感觉
the differential sense of stimuli

不是取决于一个
did not depend on

刺激增加的绝对数量
the absolute amount of a stimulus increase

而是取决于刺激物的增量
but on the ratio of the stimulus increase

与原刺激量的比值
to the original stimulus amount

他提出的规律叫作韦伯定律
The law he proposed was called Weber's law

也就是K＝ΔI/I
that was K =ΔI/I

其中I是标准刺激强度
“I” was the standard stimulus size

也就是原先的刺激强度
that is, the original stimulus size

△I是产生最小可觉差的量
“△I” is the amount of just noticeable difference

也就是相对于原先的刺激来说
that is, compared to the original stimulus

增加或减少多少量
the amount that increase or decrease in stimulus

就可以刚刚感觉到刺激的变化
that can just be noticed

而k是一个比值
And “k” is a ratio

是一个恒定的量 叫做韦伯常数
a constant amount, called Weber's constant

比如 我们买了10斤苹果
For example, we buy 10 pounds of apple

假如拿走0.5斤
if you take 0.5 pounds away

我们就能刚刚感受到重量减轻的话
and we can just notice the weight loss

那么标准刺激 I就是10
then the standard stimulus I is 10

最小可觉差△I是0.5
the just noticeable difference △I is 0.5

韦伯常数 就是0.05
and the Weber constant k is 0.05

我们在附加学习材料里面
in additional learning materials

列举了多种刺激的韦伯常数
We listed Weber constants of various stimuli

大家可以去了解
and you can learn about them

对于韦伯定律
For Weber's law

需要做两点说明
two points need to be explained

第一 对不同感觉来说
first, for different sensations

K的数值也就是韦伯常数是不同的
the values of Ks, that is, Weber's constants are different

第二 韦伯定律只适用于中等强度的刺激
second, Weber's law only applies to medium-intensity stimuli

如果刺激强度过高或者过低
If the stimulus intensity is too strong or too weak

韦伯常数也会发生变化
the Weber constant will change

就不再是常数了
and it will no longer be a constant

绝对阈限和差别阈限
Absolute threshold and difference threshold

是感觉阈限的两种形式
are two forms of sensory threshold

而人的绝对感受性
The absolute sensibility

和差别感受性
and differential sensibility of human beings

共同组成了人类感受刺激的能力
together form the human ability to sense stimuli.

好 今天的内容就讲完了
OK, that’s all for today

现在我们回顾一下主要内容
Now let's review the main content

今天我们主要讲了
Today we mainly talked about

感觉是人脑对直接
that sensation is the reflection of the human brain on the single attribute

作用于感官系统的客观事物单一属性的反映
of objective things directly acting on the sensory system

感觉的能力表现为绝对感受性
The human ability to sense stimuli is expressed as absolute sensibility

和差别感受性
and differential sensibility

这两种感受性是用
These two sensitivities

绝对感觉阈限和差别感觉阈限来说明的
are illustrated by absolute and differential sensory thresholds

绝对感受性会发生变化
Absolute sensibility might change

表现为感觉适应
and be manifested as sensory adaptation

而差别感受性它符合韦伯定律
and differential sensibility conforms to Weber's law

下次课我们将介绍
In the next lecture, we will talk about

为什么感觉对人的生存具有重大的意义
why sensations are of great significance to the survival of human

好 下次再见
OK, see you next time