The fact that humans are more perceptive than you may have thought, especially when it comes to their five senses, may actually surprise you.

How many senses are there in an average human being? Answers to this question often include seeing, hearing, touch, smell, and taste, assuming you associate senses with their receptors, such as the retinas in your eyes and the cochlea in your ears. The concept was widely acknowledged, even though Aristotle had initially categorised the skin, eyes, nose, ears, and mouth as sense organs. These are not, however, the only senses that Homo sapiens have acquired.

Due to their ability to gather information about the outside world, these senses are known as "exteroceptive" senses.

five senses
Image Source: Frontiers for Young Minds

But in addition, your body contains receptors that detect a variety of internal activities that you are totally unconscious of, such as your heartbeat, breathing, stomach churning, and many more. Traditionally, they have been combined under the umbrella term "interoception," as another sense.

9, 21 or more senses

All of your senses seem to be awake and alert when you're enjoying a wonderful dinner at your preferred restaurant. You can virtually taste the meal you're about to order, you can see the waiter, you can smell other food being made, you can feel the silk serviette in your hands and you can hear other diners talking. That's a lot of sense information to process for one person, and most people would think that's all. However, neuroscientists believe that humans can perceive far more than the five senses taught in school. While the precise number of senses is debatable, there could be 9, 21, or more, depending on how you experience and describe them.

For starters, your body has receptors that transmit data other than what we consider to be senses, such as temperature.

Also, some of your receptors serve more than one sense. Your retinas, for example, are portals for the light waves required for vision, but some retinal cells also tell your brain whether it is day or night.

Let's explore some of these 'extra' senses that you use on a daily basis but rarely give much thought to:

Thermoception

A common human response to temperature and environment is one of the body's most universal senses. Since you frequently touch hot or cold objects, the ability to sense temperature is sometimes included in the category of "normal touch." Thermoception, which also aids in regulating internal body temperature, is really regulated by two distinct brain regions (one for cold and one for hot), and is unrelated to physical touch receptors. The body's thermoreceptors deliver signals to the brain that cause our body's internal temperature to adjust and prompt us to alter our surroundings in order to avoid burns or frostbite.

Pressure

Another sense that most people overlook is the capacity to perceive pressure. This may be the sensation of increased pressure on a particular area of your body, like your ears when you drive up a steep slope, or it may be the result of sitting in an uncomfortable chair. This sensitivity to pressure enables us to physically interact with others in more suitable and comfortable ways.

Pain

Also referred to as nociception, pain sensitivity was once associated with "touch" and described as a "overload" of touch receptors. However, this notion was disproved upon the discovery of nocireceptors. In actuality, there are three distinct kinds of pain receptors: cutaneous, somatic, and visceral, which are found in the skin, bones, and internal organs.

Known as "somatic" senses, these three additional senses—temperature, pressure, and pain—are arguably the most noticeable additions to our normal five senses. But we're only getting started.

Interoceptive senses

Proprioception

The ability to detect internally where various bodily parts are at any given moment. Among many other things, if your head is tilted or standing straight, if your arms are crossed, and if your legs are bent. Orientation and coordination depend heavily on your ability to judge the relative positions of your bodily parts. For this reason, we don't have to look down at our feet when we walk or up at our hands when we're doing delicate tasks.

Equilibrioception

Our ability to move about the environment without tripping over is one of the most vital senses that is often disregarded. This feeling also aids in the detection of acceleration. This interoceptive sense of balance allows us to execute a great deal of complex movements while maintaining our balance. This is very similar to our vestibular system, which is an organ system made up of three fluid-filled canals in the ear. Small hair cells in the canals detect fluid fluctuations and send nerve impulses to the brain, allowing us to stay upright.

Organic Sense

Your mouth becomes parched from dehydration or your stomach begins to growl—these are responses of your organic sense.

Chronoception

The sense of time is distributed among several brain regions, including as the cerebellum, cerebral cortex, and basal ganglia, and is not primarily related to any one sensory system. This mechanism helps us maintain our Circadian rhythms, whereas smaller cell clusters can keep rhythm and allow us to instinctively note the passage of time in smaller chunks.

Direction

When someone says they have an excellent "sense" of direction, other people usually laugh it off or get jealous. Some people can actually sense the planet's magnetic poles vaguely, which gives them a superior sense of direction. Humans have a tiny magnetite crystal in the ethmoid bone, which is located beneath the eyes and close to the back of the nose.

This is also present in birds and other migratory animals, albeit in greater amounts. This small amount of magnetite is said to have aided in migrating and hunting along the course of evolution, giving humans a hazy sensitivity to the magnetic poles.

Chemicals

The body's chemoreceptors, which are mainly found in the heart, allow us to sense chemicals and blood-borne infections. These chemoreceptors encourage us to avoid harmful chemicals, such as moving away from smoke odours and unused food. They also react to blood acidity and oxygen concentrations, modifying levels accordingly.

Additionally, these chemoreceptors are intimately linked to our body's capacity to throw up in order to rid itself of anything really toxic.

People may claim to have a "sixth sense" for many different reasons—seeing dead people is not the only one—but if they claim to have much more, they are not technically wrong.
Now, you can either tell them more about the additional senses and how much more advanced our senses are overall, or you can just agree with them the next time they make up the claim that they have the "sixth" sense.

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