5 senses 'unmask' limits the peak of humans

Researchers point out, 5 human senses also have certain limitations .

The human body has certain limitations - such as the speed limit, the time to hold the breath, the limit of thirst . Today, we will explore the "peak" limits in my five senses. people.

1. Vision

Many people think that sight is the most important sense. This can be said to be correct, because humans need bộ brain neurons to receive and process image information. And try to see what our visual limits are.

Limit viewing angle

Healthy human eyes with a total binocular angle of 200 degrees horizontally (of which about 120 degrees are common angles for both eyes) and 135 degrees vertically. These angles can be changed, based on the location of the eyes on each person's face.

In nature, predators - including humans - have two eyes in front of the face, while the animals below the eye food chain are on either side of the head - like the eyes of the dove. the sentence.

With such an eye structure, the 'prey' has a wider viewing angle, but in return the received image quality is very low. However, in terms of being able to be eaten at any time, this is a very reasonable trade-off.

Blind spot

The human eye consists of many cells that receive light. The object reflects light, these cells will receive and transfer image information to the brain through the optic nerves.

Anatomical structure of the human eye: Blind Spot is a blind spot

And the only problem is that the optic nerves have to go through the photoreceptor cells behind the eyeball, so that this point does not have the nerve to receive light, which means that it cannot receive light. This point is called the 'blind spot'.

Normally, blind spots will not be a big problem when we have two eyes, along with a vision that is really good, the brain will receive information from both eyes to make up for the defect. each eye separately. But if it falls into a situation where one eye is required, the blind spot will cause a lot of trouble, even if it is dangerous to move at a high speed.

2. Hearing

Hearing is also an extremely important sense, even when it can sometimes go beyond sight when it can help people avoid risks. However, did you understand them all?

We all know that there is a barrier in the inner ear called the eardrum. When the outside noise is transmitted into the ear with the eardrum, the eardrum will vibrate. The sound waves of this oscillation will continue through the small bones that pass into the inner ear, then turn into nerve signals that travel to the brain. Then, we will feel and hear the sound.

Limit listening threshold

A healthy person can hear sounds in the frequency range of 20 - 20,000 Hz. The maximum listening threshold decreases with age. The minimum listening threshold (absolute threshold of hearing) is the term for the smallest sound intensity that a human ear can hear without any disturbing sound. Each person's listening threshold varies, varying with age, and especially depends on the frequency of the sound.

Ordinary people have a minimum hearing threshold of 0-5 decibels (such as the sound of leaves falling to the ground, the sound of dripping water from the tap to the sink), but statistically, the minimum negative intensity can be heard even down to -5 decibels. This ability to hear people at this threshold is quite rare, this ratio is about 1/10 people.

Try checking the "big" level of ears here!

3. Taste and smell

Taste and smell are governed by two different receptors - the tongue and the nose, but have a close relationship with each other. For example, if you have a stuffy nose (loss of smell), the taste of the food will be significantly reduced (taste).

Limited to feel the taste

Taste can be considered the most 'weak' sense of the 5 senses of human beings. Because even the taste felt by the tongue can be completely misleading if there is an effect of 'smell' or even 'color'.

Frédéric Brochet's research proved it. He invited 57 wine experts to taste two glasses of wine - red and white but in fact they were one. However, no one can detect the red color of wine is food color and they describe the taste of red wine like the taste of any other red wine.

Super taste and taste sensation

We understand that 'super tastes' are people with special tastes sensitive to 4 basic tastes: bitter, sweet, sour, salty. Linda Bartoshuk - a pioneer in the field of physical research, psychology has discovered and introduced the concept of "super tasting".

Tongue image of "super tastes"

Bartoshuk has proven that taste sensations are closely related to the mushroom-shaped spines on the tongue - or the sense of taste area. The blades of super tastes will have more mushroom-shaped spines, which give a stronger reaction to different tastes, especially bitterness.

However, the determination of the limit of perceived flavors - even the smallest - is still a big challenge for many scientists around the world.

Odor threshold threshold

Similar to the taste threshold, the olfactory threshold is also difficult to determine. According to the professor, ENT doctor Thomas Hummel, has had a lot of research and tests on the sense of smell, but very few of them are effective, due to lack of uniformity, lack of normative data and restrictions on test management.

4. Tactile

Tactile research is complex, because it involves a sense of pressure, temperature, and even an itching sensation. Most of the sensations and mechanisms of formation are unknown, but subcutaneous nerves are thought to be the cause.

'Two points discrimination' (two points discrimination)

One thing is for sure, tactile tendencies are more pronounced at points of concentration of neurons. Neuroscientist Marjorie A. Murray has come up with a simple experiment to prove this - experimenting on 'two distinct points'.

The experiment is as follows: You need 1 volunteer. First, bend a paper clip into a U shape, so that the two U-shaped edges are equal and separated by 2cm. Then gently press the U-tip on the back of the volunteer's hand (this person cannot see).

If he / she feels "a single point", try pressing the paper clip to another area, until the volunteer indicates that he or she feels "two points". Now move the paper clip around that point, and identify the 'two-point feel' area on the volunteer's hand.

Subcutaneous receptors are not evenly distributed throughout the body

The 'two-point' areas you've identified are the focus points of many tactile sensing cells. And according to Murray, subcutaneous receptors are not evenly distributed throughout the body.

In areas such as fingertips or lips, these receptors are significantly more than some areas such as the back, thighs, etc. That's why people are always more sensitive to what comes in contact with their hands or face, in when the back is not like that.