Our everyday existence is an illusion. It’s everything in our minds and only perceived by the senses. The human senses are the organs through which we process all of life’s information. The senses are the portals through which we experience the glory of life and all its wonders. The vibrant colors of a sunset and the gentle touch of a loved one are just two examples of the many things that shape our views and sense of self. What they are, how many there are, and how they all function together are all discussed in this article.
But first, let us understand that,
Research Highlights
What is a Sense?
The conventional definition of “sense” is “a facility by which the body perceives an external stimulus; one of the faculties of sight, smell, touch, taste, and hearing.”
In easy terms, A sense is a physiological capacity or ability that allows an organism, especially humans, to perceive and interpret environmental information. It is how we acquire information about the external environment and our internal state.
Humans rely on multiple senses to perceive and comprehend reality.
The Five Basic Human Senses
1. Sight (Vision)
Vision, or sight, is one of humans’ five basic senses. It’s a major factor in how we take in information and interpret the world. The eyes, optic nerves, and brain play essential roles in human vision.
Sight helps humans see the world as seen via cones and rods in the eyes. The rods in the eyes are responsible for interpreting the contrast and the range of greys present in a view. The cons interpret the color, including the saturation, hue, and tint. The lenses in the eyes have the job of interpreting blurriness, sharpness, and depth.
The ability to see gives us access to information that significantly shapes how we engage with the world. At the same time, the sense of vision can even affect the body’s sleep-wake cycle. In visually impaired individuals, the absence of light can desynchronize the circadian rhythm, influencing the quality of their sleep.
2. Touch (Somatosensation)
Touch, also known as tactile perception, is one of the five fundamental senses possessed by humans. It is the capacity to detect and perceive physical sensations through the skin, the primary sensory organ for touch and the biggest organ in the body.
Mechanoreception is the scientific name for the sense of touch, and according to the Stanford Encyclopedia of Philosophy, touch is believed to be the first sense humans develop.
The skin on the lips and soles of your feet is incredibly sensitive and responsive to touch, while there are separate touch receptors in your tongue and throat.
The sense of touch is essential to our psychological, emotional, and physiological health and interactions with the outside world.
Studies have shown that physical contact has a calming effect on lonely or anxious individuals. Touch also affects decision-making. According to six studies by Harvard and Yale’s psychologists published in Science on June 24, 2010, texture can be connected with abstract concepts and impact decision-making.
3. Hearing (Audition)
The sense of hearing is what allows us to pick up and make sense of sound waves. Ears are vital because they allow us to hear others and appreciate the world around us. The ear is composed of three parts: the outer ear, the inner ear, and the middle ear. All sounds are fundamentally vibrations; therefore, the outer ear transmits these vibrations into the ear canal, where the brain converts them into meaningful sounds. In addition to hearing, this sense is essential for body balance or equilibrium.
Hearing is essential for communication, environmental awareness, emotional impact, speech development, and spatial perception, among other functions. It is an essential aspect of our sensory experience, connecting us to the world and enhancing our understanding of others and our surroundings.
4. Taste (Gustation)
Think about the first time you tried a piece of delicious chocolate cake. When you put a piece of cake on your tongue, tiny receptors undergo a chemical reaction along with saliva, allowing you to feel the cake’s sweet flavor. This is what we call as sense of taste.
There are approximately 10,000 taste receptors on the tongue, palate, and roof of the mouth. The little bumps on the tongue, roof of the mouth, and back of the throat are responsible for our heightened sensitivity to flavor. Without them, you wouldn’t have been able to enjoy the flavor of any of the delicious meals you’ve eaten throughout your life.
We experience sweet, sour, bitter, salty, and umami flavors. Umami, the fifth sense, is a Japanese term for a flavorful, meaty flavor, an amino acid found in hot spicy foods. It is prevalent in protein-rich foods such as meats, dairy, and crustaceans and is under study.
5. Smell (Olfaction)
Smell is the last of the five senses. Smell, or olfaction, is unique because the organ that perceives it is related directly to the brain. Because of this, your sense of smell will be exceptionally strong.
The olfactory bulb, a large nerve in the nasal cavity, detects odors and alerts the brain when inhaled. Higher concentrations of odor molecules stimulate the brain’s olfactory bulb more intensely. This renders strong odors offensive and nauseating. Lighter aromas transmit softer signals to the brain. What are the types of odors, and how can we prevent foul odors? Learn here in our article.
Our sense of smell is also closely related to our sense of taste. It was previously thought humans could only take in around 10,000 distinct smells. Still, research published in the May 11, 2017, edition of the journal Science reveals that people can differentiate among 1 trillion different smells.
These brain regions are linked by neuroscientists to learning and memory. Multiple studies have demonstrated that smells can improve learning efficacy.
Senses for which you don’t have receptors are also developed by your brain. Taste and smell information is used to produce the sensation of flavor, while touch and temperature data are used to create the sensation of moisture.
We Have More Than Five Human Senses
We have been taught for centuries that we only possess five senses – sight, hearing, taste, touch, and smell – a basic fact rooted in our conception of human nature. What if, however, I told you that the story of our senses is significantly more captivating than what meets the eye?
When Aristotle came up with his definitive list, he linked them to visible “Sense Organs.” But modern neuroscience recognizes there is more to it than that. Let’s explore the ways in which using all of our senses might enrich our lives.
6. The Sixth Sense
The ability to receive information beyond the range of the five typical senses is sometimes called a “sixth sense” and is commonly related to intuition. Some people think it includes picking up on hidden environmental signals or energy, though this is still up for discussion.
7. Itch Sensation
The sensation of discomfort or irritation on the skin that causes the need to scratch or touch the region is known as itch or pruritus. Unlike other touch sensations, this one uses a separate sensor system. Skin irritants, allergies, bug bites, and underlying medical disorders are some potential causes.
Like pain, itching has a defensive purpose. When your skin starts to itch, it might indicate something is wrong. Scratching the irritated region could eliminate the source of the itch or at least speed up the healing process. However, itching that persists for an extended period of time might be a sign of a more serious medical condition.
8. Stretch Sense
Humans have different sensors for detecting stretches in the body, such as in muscles, GIT tracts, urinary tracts, blood vessels, or muscles. For example, when you need to urinate or defecate, either bloated or gassy, the stretch receptors in the area are activated, sending the signals to address the body to act. This sensation also includes the construction of blood vessels associated with headaches.
Humans are also aware of spatial stuff, like when objects are near us or in our personal bubble. These senses also help to determine where we are inside the space, for example, a small room or a bigger hall. Such as,
9. Nociception
Pain is what we call it in easy language. This was once thought to occur when one’s senses become overloaded, particularly the touch sensation. However, it is currently recognized as a distinct human sense type. It serves a vital purpose in alerting individuals to harmful behavior or unpleasant sensations.
Pain receptors can be found in the skin, muscles, joints, and internal organs and have different names as cutaneous for skin, somatic for joints and muscles, and visceral pain for the pain felt in organs.
Rarely a person will be born unable to feel pain. This is usually the result of a mutation in a specific gene, dramatically increasing the likelihood that they will encounter a wide variety of painful injuries, both minor and major.
10. Thermoreception
The capacity to detect heat and cold is called thermoreception. Feeling the heat of the sun or the cold of a winter breeze are examples of how this sense is put to use.
Thermoreception is also considered to be more than one sense, not only because there are two hot/cold receptors but also because the brain contains thermoreceptors with an entirely distinct detection mechanism.
These thermoreceptors in the brain monitor the body’s internal temperature. The skin’s thermoreceptors allow us to detect the ambient temperature. This helps us stay safe from extreme temperatures, such as those that can cause burns or frostbite.
11. Proprioception
This human sense enables you to determine the location of your body parts with other body parts. This sense constantly works in little ways, such as when you scratch an itch on your foot without looking at it to determine its location. Or by walking abruptly after getting up without tripping.
Scientist links this human sense to the sensors inside the points, muscles, and ligaments that give awareness of presence to your body.
It’s also one of the things police officers test when they suspect a drunk driver is behind the wheel. This is tested by the “close your eyes and touch your nose” test.
In a 2016 study published in The New England Journal of Medicine, researchers found that individuals with a particular mutation in the PIEZO2 gene had a reduced sense of proprioception. Physiotherapy and targeted exercises can enhance proprioception in individuals with sensory deficits or rehabilitate from injuries.
12. Equilibrioception
We need not simply be aware of our spatial location to stay upright. For this purpose, we have a mechanism called equilibrioception. The vestibular system in the inner ear aids with this process, along with the visual system and proprioception, to achieve balance.
We all have sensed it as a child twirling around and around on the front lawn knowing that once your equilibrioception is thrown off, you will collapse and take a moment to regain your balance.
13. Kinesthatoception
We know about the human awareness of proprioception, but that sense is for static cases. When moving, like in a car or walking, this sense is called Kinesthatoception to Kinesthesis.
Kinesthetic sense can incorporate a broader spectrum of bodily movement and awareness-related sensory experiences. It encompasses proprioception (the sensation of body position) and the sense of body movement through space. The kinesthetic sensation also involves perceiving force, effort, and muscular tension during movement.
Constantly at work while awake, kinesthatoception works with other senses like touch and vestibular (balance) perception to give you a full picture of your body and how it moves.
Motor skills, balance, and coordination are all possible consequences of a compromised kinesthetic sense. Enhancing kinesthetic awareness and compensating for sensory impairments can be aided by physical therapy and targeted exercises.
14. Chemoreception
The sense is denoted by our bodies sensing foreign substances such as medicines, chemicals, and hormonal imbalances. It is also involved in the vomiting reflex.
15. The Sensation of Hunger And Thirst
The sensation of hunger is considered a separate human sense as it regulates the level of sodium in our bodies, which helps us decide when we should eat.
Like hunger, this system lets your body keep tabs on how well-hydrated it is, so it can signal to you when you need to replenish your fluid reserves.
16. Interoception
Try to feel your heartbeat for a moment without looking for a pulse. If you can do that without much trouble, you have a strong sense of interoception, which only about 10% of people have.
It may sound like a cool party trick to feel your own heartbeat and other internal organs. Still, research reveals this human sense strongly correlates with high emotional intelligence. According to studies, those with heightened ‘cardiac interoception’ are better able to feel and understand a broader range of emotions, as well as the feelings of others.
Like balance, it is an advanced meta-sense that integrates input from various bodily systems. Initially, scientists believed its function was to aid in homeostasis, the process by which your body maintains equilibrium so that you don’t have too much or too little of, say, iron, copper, calcium, or sodium, don’t overheat or underheat, use about as much energy as you take in, and so on. In recent years, however, scientists have learned that interoception might aid us in areas like motivation, emotion, and self-awareness, proving that “trust your gut” is more than a cliche.
17. Chronoception And Circadian Rhythm
Chronoception is our capacity to perceive the time frame of events and experiences. According to studies, humans, especially children, have a precise sense of time. We all can give the idea of how long a minute or an hour can be. But this can also be disturbed by changes in our circadian rhythm.
18. Synesthesia
Some people, known as synesthetes, can simultaneously experience sensations like a crossover in many senses in response to a single stimulus. It is a rare human sense found in 1 out of 2000 people.
The most common form is grapheme-color synesthesia, in which each number or letter is associated with a specific color or shade.
19. Magnetoreception
It is the magnetic field detection capability. Humans, in contrast to most birds, have relatively weak magnetoreception. However, experiments have shown that humans have limited awareness of magnetic fields. It has been suggested that ferric iron deposits in our noses play a role, but the exact process is still unclear. Some studies also suggest that humans with magnetic implants have been demonstrated to have significantly enhanced magnetoreception compared to those without.
How Do Our Senses Work Together?
Your brain almost never relies on data from just one sense when working. Studies have demonstrated that our senses do not function independently but cooperate to provide a more complete and accurate picture of our external environment. This means our brain interprets and integrates data from all our senses to construct a complete and consistent representation of the world, known as multisensory perception.
For example, as a plane takes off, the cabin in front of us appears to be elevated even though our field of vision has not changed. Our sensory canals indicate that we are tilting rearward, which alters our field of vision.
Using another simple example, a cup, our eyes see an exterior, but because we hold it and feel it, our brain receives additional information and recognizes it as a three-dimensional object. Here, our senses of sight and sensation collaborate to give us a complete picture.
But with time and age, this system usually declines and causes some evident changes in the sensory system; what are these changes and how we can manage them are discussed in this article. Click here to take a look!
Senses Not Possessed by Humans
Certain senses are exclusive to the animal kingdom.
- Electroception – the capacity to detect electrical fields in the environment. Sharks can detect electrical fields in their environment, including those emitted by unknown prey.
- Polarized light – many organisms, such as invertebrates and birds, use polarized light to determine their direction of travel.
In conclusion, thinking humans only have five senses is a false simplification, and enlisting them means we are leaving many things that actually keep us alive and functioning daily.
Each of our above-mentioned senses contributes significantly to how we take in the world. Our senses provide a rich, multifaceted experience, from the sixth sense of interoception through the sensation of time and beyond. Consider how you feel when you are strolling. Observe the variety of sensations you experience. Perhaps you observe a colorful sunset. Or hear a stream’s water flowing over rocks. You may encounter fallen leaves.
We should expect to learn even more about the human senses as technology and study develop. Understanding oneself and the world around us is only one of many potential outcomes when we accept the multifaceted nature of humans.
