Synesthesia: The Sixth Sense

Catherine Rasgaitis
3 min readMar 25, 2021

The majority of people experience the world through the five basic senses: sight, sound, smell, taste, and touch. But around 4% of the population naturally possess what is often called the sixth sense — synesthesia.

More accurately, synesthesia is a blending of senses. It occurs when the activation of one sense triggers the stimulation of another, unrelated sense.

People who have this ability are known as synesthetes. While all synesthetes have a different experience, the most common forms of synesthesia tend to be interpreted through sight. A typical example of this is “seeing” letters, numbers, or sounds as colors.

In similar versions of this type of synesthesia, seeing certain words or shapes can stimulate a synesthete’s sense of taste or sound.

Another notable kind of synesthesia is known as “mirror touch.” The effect of mirror touch synesthesia triggers a synesthete’s own sense of touch when they see someone else being touched. In other words, the synesthete feels a “mirror” of the touch sensations experienced by someone else.

Mirror touch synesthetes also have an enhanced sense of empathy compared to the average person. According to a study by Cognitive Neuropsychology, mirror touch makes a person better able to precisely recognize emotions based on a person’s face.

Across all variations of synesthesia, research shows similar magnifications of synesthetes’ sensory perception. For example, some synesthetes are better able to differentiate between similar smells or colors, more so than people are otherwise capable of doing.

Synesthesia also improves memory. Daniel Tammet, one particularly impressive synesthete who also falls on the autism spectrum, visualizes numbers up to 10,000 with a distinct color, shape, and texture. His synesthesia enabled him to easily recite pi to over 22,500 places.

This ability also makes it possible for Tammet to quickly perform complicated mathematical operations in his head. When multiplying numbers, Tammet claims, “I see two shapes. The image starts to change and evolve, and a third shape emerges. That’s the answer. … It’s like maths without having to think.”

Tammet’s talents don’t stop there. Thanks to his unusual brain, Tammet…



Catherine Rasgaitis

2x Top Writer — Space & Innovation | Enthusiast of all things tech and science!