Health Talk: Synesthesia

For Laura Rosser, numbers are always associated with colors. The number two is always orange and the number five always red. Rosser also associates colors with music. While playing the piano, she “sees” the note E flat as turquoise and the note F sharp as yellow-green. Many notes together create a medley of colors for her. Although Rosser’s story, reported by ABC News, may suggest that she simply has a very creative and poetic mind, these phenomena can be attributed to a condition called synesthesia. Simply put, Rosser’s brain has some internal cross-wiring that involuntarily activates one sensory pathway on the stimulation of another sensory pathway. Thus when she reads a number or hears some music, her sensory pathways for seeing color are immediately activated.

“Color synesthesia,” as this is called, is not the only form of the condition. The ABC News article also narrates the case of James Wannerton who can “taste” words. For Wannerton, the word “change” tastes like cheese and the words “roasted nuts” taste, not like nuts, but like burned meat. Certain words can be especially distasteful for Wannerton. The name Derek, for example, tastes like earwax.
Like Rosser and Wannerton, most synesthetes have this condition since birth. Scientists have recently discovered that the condition could be hereditary and could have its roots in genetic mutations. According to the New Scientist, researchers at the Imperial College London and the University of Oxford have discovered that a region on chromosome 2 may be responsible for the condition.
What is particularly interesting about this find is that the same chromosomal region has been associated with autism and epilepsy. This discovery has led scientists to believe that the three conditions may share some common underlying neurological mechanism.

Other chromosome regions which have been linked to this disorder include regions on chromosomes 5, 6, and 12. These regions are responsible for directing the way the brain gets structured.
Scientists have still not figured out which exact genes are responsible for the disorder but hope that the findings will shed some light on the functioning of the brain. Research in this field has also called to question the fact that the condition is completely hereditary and if certain environmental factors cause the condition.

ScienceDaily reports that color synesthesia is influenced to a certain degree by environmental factors. Studies conducted by scientists at the University of Edinburgh and University of Sussex revealed that color synesthesia has some certain common characteristics in many individuals. The letter A, for example, is always associated with the color red, while the letter V is associated with the color purple.
Scientists believe that this color-letter association has to do with the way people learn languages. A is commonly used in English and is hence associated with a very common color term — red. V, a rather uncommon letter, is associated with the relatively uncommon term purple. This shows that external factors can influence synesthesia to a large degree.
Even more surprising is the discovery that hypnosis is able to induce synesthesia in individuals normally not exhibiting the condition.

Medical News Today describes a study conducted by scientists at the University College London in which subjects who were hypnotized displayed color synesthesia. The scientists who conducted the study believe that hypnosis may cause certain suppressed connections in the brain to become activated, causing the various sensory pathways to become interlinked.
These researchers believe that synesthesia is not caused due to abnormal connections in the brain, but due to increased activation of existing links in the brain.
Research has thus found some insights into the condition, but the actual mechanism of the condition still remains a mystery.

As for those with this condition, their daily lives are not affected much by the condition. In fact, many have developed artistic abilities because of the condition.
As Rosser put it, “I see it as a gift, as a sort of spiritual god thing that enables more intuition, whether it’s musical or even with people to be able to see some extra things out there.”