We believe that synesthesia is a defect in perception because we believe that our senses behave like watertight compartments. However, this is not the case: it has been shown that if we listen to certain sounds, the sweet taste of a food is enhanced.
People with this rare condition called synesthesia see sounds, smell colors, and taste shapes. In other words, synesthetes show us that there are people who have a different experience of the world. Not only different but we could even say better. For a synaesthetic, the rest of the human beings see the world in a boring way, as in black and white; they have the possibility of perceiving a world where letters, numbers or sounds are accompanied by a variety of colors. A synaesthetic does not perceive sounds, sights, smells, tastes and touches separately, but the stimuli received by his sensory organs are mixed in his brain.
Interestingly, all human beings are born synesthetics: the same response is obtained in the cerebral cortex regardless of whether the stimulus is a bright light or a loud noise. Later, each sense is segregated and ends up being perceived in different places in the cortex: sounds appear in the temporal lobe and visual stimuli find a response in the occiput. Apparently, these “sensory islands” are not created in the brain of synaesthetics, but rather, for some yet undiscovered reason, the synaptic links remain more or less intact.
Why, then, do we suppose that they do not perceive reality correctly? We can only hold on to the principle of mediocrity: the common is the right thing to do. But there is no way to decide which is the “right” way. It is not worth saying that because there are more of us, the synesthetes are not right.
