Synesthesia, It's All in the Mind

• While most of us experience the world through orderly, segregated senses, for some people two or more sensations are comingled.
• Those with synesthesia may feel or taste sound, or hear or taste shapes.
• The chords of a strumming guitar may be a soft brushing sensation at the back of an ankle, a musical note may taste like pickles, a trumpet may sound “pointed”, the taste of chicken may feel “round”.
• While synesthetes’ perceptions are consistent over time, they are not shared with each other. Letters, for instance, don’t produce the same color for all synesthetes.
• Even relatives who have synesthesia see things differently.
• According to one study, only one letter elicits consensus among a majority of synesthetes; that is, they see “O” as a shade of white.
• At times, during the last 200 years of research, synesthetes were considered to be mentally defective and at other times they were idealized as artistically gifted. Often, they were not believed.
• More recently, scientists have discovered that synesthetes frequently have more than one form of the trait.
• A small group of scientists in the United States, the United Kingdom, Canada, Germany, and elsewhere are currently doing research with volunteers to try to find out why synesthesia is more common in women than in men and why it is an international phenomenon.
• In 1812, Dr. G.T.L. Sachs published the first scientific treatise on synesthesia. In it, he described how he and his sister experienced vivid color sensations when seeing, hearing, or even thinking, about various vowels, consonants, names, and numbers.
• For the next 70 years, the only synesthetes to describe their symptoms publicly were doctors and researchers whose curiosity about their conditions were greater than their fear of being ridiculed or labeled insane.
• Despite the obvious intelligence of the physician witnesses, most researchers viewed synesthesia as an illness.
• In 1864, Ernest Chabalier, a French doctor, described how a friend who was also a physician, saw colors when he heard vowels, numbers, time periods, and proper names; however, Chabalier thought it significant that his friend had suffered hallucinations as a child.
• A decade later, when Dr. Jean Nussbaumer, of Vienna, vividly described his own and his brother’s colored hearing, another Austrian physician suggested, not too tactfully, that the Nussbaumers were mentally unbalanced.
• Only in the late 1870’s did George Henry Lewes offer a more sympathetic protrayal, comparing the twinned sensations of synesthetes to his own feeling of a chill in his legs when he witnessed an unpleasant sight.
• Synesthetes appear to be normal in every other way. Some even appear to have above average ability in recalling information.
• In the decades surrounding the turn of the century, synesthetes came out of the closet and pseudo-synesthetes came out of the woodwork. Among the literati, having synesthesia became the yardstick for measuring an artist’s genius.
• The intensity of association of a letter or word with a particular shade is a hallmark of “colored-language” synesthesia.
• Despite a few negatives, synesthesia more often provides pleasure.
• As research into synesthesia continues, scientists are optimistic they can gain insight into human consciousness and perception in general; however, reality isn’t the same for everyone.

When you read a newspaper or listen to someone speaking do you see a rainbow of colors? If so, you might have synesthesia.

Synesthesia is a strange blending of the senses in which the stimulation of one modality simultaneously produces sensation in a different modality. Synesthetes hear colors, feel sounds and taste shapes. What makes synesthesia different from drug-induced hallucinations is that synesthetic sensations are highly consistent: for particular synesthetes, the note F might be a reddish shade of rust, a 3 can always be pink or truck can always be blue.

All synesthetes are not the same

The estimated occurrence of synesthesia ranges from rarer than one in 20,000 to as many as one in 200. Of the various manifestations of synesthesia, the most common involves seeing monochromatic letters, digits, and words in unique colors—this is called grapheme-color synesthesia. One rather striking observation is that such synesthetes all seem to experience very different colors for the same graphemic cues. Different synesthetes may see 3 in yellow, pink or red. Such synesthetic colors are not determined by meaning, because 2 may be orange but two can be blue and 7 may be red but the word seven will be green. Even more perplexing is that synesthetes typically report seeing both the color the character is printed in as well as their synesthetic color.

Synesthetes report having unusually good memory for things such as phone numbers, security codes, and polysyllabic anatomical terminology because digits, letters and syllables take on such a unique panoply of colors. Synesthetes also report making computational errors because 6 and 8 have the same color and claim to prejudge couples they meet because the colors of their first names clash so hideously.

Are synesthetes overly imaginative?

For too long, synesthetes were dismissed as having rather overactive imaginations, confusing memories for perceptions or taking metaphorical speech far too literally. Recent research, however, has documented the reality of synesthesia and is beginning to make headway into understanding what might cause such unusual perceptions.

In one experimental task, people were asked to say the color of the ink a word is printed in as quickly as possible (for example, responding "pink" to and "blue" to ). For lexical synesthetes, these words take on unique colors. When the synesthetic color matches the ink color, responses are fast, but when the synesthetic color mismatches the ink color, responses are slow, presumably because subjects need to resolve the conflict over which color name to respond with. Although such results demonstrate that synesthesia is automatic, in the sense that they cannot turn off their synesthesic experience even when it interferes with a task, these results do not reveal whether synesthetic colors are perceptions or memories.

Claims for the perceptual reality of synesthetic colors have been bolstered by recent functional brain imaging studies by researchers in the U. K. showing that synesthetic color activates central visual areas of the brain thought to be involved in perceiving real colors.

No one claims to know what causes synesthesia

The causes of synesthesia remain unknown. Some scientists have suggested that everyone is born synesthetic but that the typical developmental trajectory results in these highly interconnected brain areas have become far more segregated. We do not know why synesthetes retain some of these anomalous connections. A biological determinant may be partially at work in certain cases of synesthesia, because the condition tends to run in families; moreover, nearly six times as many women as men report synesthesia. Whatever its causes or origins, synesthesia provides cognitive neuroscientists with a unique opportunity to learn more about how the brain creates our perceptual reality.