Recent research challenges the long-held belief that humans possess only five senses. A growing number of cognitive scientists and neuroscientists now argue that the human sensory system may encompass as many as 33 distinct senses. This perspective has gained momentum through studies conducted by the Rethinking the Senses project at the University of Glasgow.
Traditional notions of the five senses—sight, sound, smell, taste, and touch—fail to account for the complexity of human perception. Researchers emphasize that additional sensory systems, including balance, body position, internal body awareness, temperature, pain, and proprioception, significantly enhance our lived experiences. This broader understanding of sensory perception has implications for how we interact with the world around us.
Leading this exploration, Charles Spence, a neuroscientist at the University of Oxford, suggests that humans likely possess between 22 and 33 senses. He explains that sensory information does not operate in isolation but instead blends continuously, shaping our experiences in profound ways. For instance, the act of tasting food involves not just the tongue but also the sense of smell and touch.
One of the most illustrative examples of this interaction is the sense of taste itself. The tongue can identify only five basic flavors: sweet, salty, sour, bitter, and umami. However, the rich flavors of specific foods, such as strawberries or coffee, emerge from odor molecules that travel from the mouth to the nasal cavity during chewing. Additionally, the texture of food—whether creamy, firm, or thin—also plays a crucial role in how we perceive flavor.
Understanding Sensory Blending
The blending of sensory information occurs throughout the body. Proprioception allows individuals to recognize the position of their limbs without visual cues. The vestibular system, located in the inner ear, helps maintain balance and spatial orientation, while interoception monitors internal states like hunger and heart rate. Some researchers further identify a sense of agency and a sense of ownership, both of which can be disrupted in individuals who have suffered strokes, leading to feelings of detachment from their own limbs.
Experiments conducted by the University of Glasgow illustrate the flexibility of these sensory systems. In one study, altering the sound of footsteps made participants feel either lighter or heavier while walking. In another experiment, background noise from aircraft changed the perception of food flavors, making salty and sweet tastes less intense while enhancing savory notes. This phenomenon explains why certain foods, such as tomato juice, may taste better when consumed at high altitudes.
Research indicates that perception is a coordinated process. Visual input can shift with balance, while smell influences texture, and sound alters flavor. All sensory modalities remain active, even during daily activities dominated by screens. The conventional story of five senses overlooks the intricate network of signals that continuously informs our experiences.
In summary, the understanding of human senses is evolving beyond the simplistic five-sense framework. As researchers continue to explore the complexities of perception, it becomes increasingly clear that humans experience the world through a rich tapestry of sensory inputs, which work together to shape our understanding and interaction with our environment.
