Researchers in the fields of neuroscience, psychology, and philosophy state that everyday human experience involves much more than sight and hearing. Even when spending long periods in front of screens, people continue to constantly use their senses, often unconsciously.
According to specialists, when the state of attention is heightened, it is possible to perceive the rough or smooth texture of objects, muscular stiffness in the shoulders, or the softness of food. Common activities such as brushing one’s teeth or taking a shower involve multiple simultaneous sensations, including the tingling of toothpaste, the sound and temperature of running water, the smell of shampoo, and later the aroma of freshly brewed coffee.
Historically, Aristotle defended the existence of five human senses. However, like other conceptions of Antiquity, this idea has been revised by modern science. Contemporary studies indicate that the number of human senses may be significantly greater.
According to current research, nearly all human experience is multisensory. Visual, auditory, olfactory, and tactile perceptions do not occur in isolation but simultaneously, composing an integrated experience of the environment and the body itself.
Researchers point out that what a person feels can influence what they see, just as visual stimuli can alter auditory perception. Experiments demonstrate that fragrances added to shampoos modify how hair texture is perceived. The scent of roses, for example, tends to make hair feel silkier.
Studies in the field of food perception indicate that aromas added to low-fat yogurts can make them seem richer and thicker without the need to increase emulsifiers. This occurs because the perception of odors in the mouth, which reach the nasal passages, is influenced by the viscosity of the liquids consumed.
Professor Charles Spence of the Crossmodal Research Laboratory at the University of Oxford states that many neuroscientists estimate the existence of between 22 and 33 distinct senses. Among them is proprioception, which is responsible for informing the position of body limbs without the need for visual observation.
According to researchers, the sense of balance depends on the vestibular system located in the auditory canals, together with vision and proprioception. Another relevant sense is interoception, which allows the perception of internal bodily changes, such as variations in heart rate and the sensation of hunger.
There is also the sense of agency, related to the perception of control over one’s own movements. In patients who have suffered a stroke, this sense may be impaired, leading some to believe that their limbs are being moved by another person.
In addition, there is the sense of body ownership. Clinical reports indicate that some post-stroke patients recognize sensations in a limb but feel that it does not belong to them.
Researchers emphasize that some traditionally recognized senses are, in fact, combinations of several sensory systems. Touch, for example, involves distinct perceptions such as pain, temperature, itch, and pressure. Likewise, the experience of taste results from the integration of touch, smell, and taste.
Gustation refers to sensations detected by receptors on the tongue responsible for salty, sweet, sour, bitter, and umami flavors. Flavors such as mint, mango, strawberry, or raspberry do not have specific receptors on the tongue.
According to specialists, there is no mathematical combination capable of explaining fruit flavors solely from basic tastes. Most of what is perceived as flavor results from the action of smell.
During chewing or drinking, odor compounds are released in the mouth and reach the nose through the nasopharynx, located at the back of the throat. This process is fundamental to the gustatory experience.
Touch also plays an important role by integrating aromas and flavors, influencing food preferences, such as the choice between soft or firm egg yolks, as well as the appreciation of creamy textures.
Vision, in turn, is influenced by the vestibular system. Studies show that during an aircraft’s takeoff, passengers tend to perceive the cabin as tilted backward, even when the visual relationship of objects remains unchanged. This perception results from the combination of visual stimuli and information from the vestibular system.
The study of the senses constitutes an interdisciplinary field. Philosophers, neuroscientists, and psychologists work jointly at the Centre for the Study of the Senses at the School of Advanced Study, University of London. In 2013, the institution launched the project Rethinking the Senses, directed by Professor Sir Colin Blakemore.
Among the project’s findings is the observation that altering the sound of one’s own footsteps can change the perception of body weight. Research also showed that audio guides at the Tate Britain museum, which simulate the speech of figures depicted in artworks, allow visitors to remember more visual details of the works.
Other studies indicate that aircraft noise interferes with taste perception. While salty, sweet, and sour flavors are reduced in the presence of white noise, umami remains unaffected. As tomatoes and tomato juice are rich in this component, their flavor tends to be enhanced during flights.
These phenomena are presented in the interactive exhibition Senses Unwrapped in London, where the public can experience sensory illusions, such as those involving size and weight. One example features curling stones of different sizes that appear to have different weights, even though they all have the same mass.
According to researchers, situations like these highlight the complexity and interdependence of human senses. A brief pause in daily routine can reveal how multiple sensory systems operate simultaneously to enable an integrated perception of the surrounding world.
