In 1812, George Sachs submitted a medical dissertation in the German university town of Erlangen that described his own remarkable condition. Sachs was an albino. His hair and skin were of purest white, as were those of his youngest sister. He had been born in Saint Ruprecht, a small and lonely village in a mountainous area, and was the oldest of five children. He was a religious and modest man with a high educational level. At this point in time, albinism had mainly been documented in Africa, where a white-skinned baby born to black parents would be treated as a monster, and barred from breeding. During the slave trade, these black albinos were sometimes acquired as curiosities to serve in the mansions and palaces of Europe. The great showman, Phineas Barnum, would later include albinos in his travelling circus. Our colorful albino, George Sachs, was âdiscoveredâ by Dr Julius Schlegel in August 1795 at the age of nine. We know little of their relationship but Schlegel and Sachs would go on to become colleagues and, indeed, one of Schlegelâs motivations for advancing Sachs was to prove that an albino can have a normal intellect, and could even practice as a doctor. Albinism is now understood in terms of genetic mutations in the proteins that make skin pigmentation and there is no logical reason why this would affect intellect. However, the story in this book is not concerned with the outward manifestations of color such as the color of our skin or hair. It concerns how some people color their mental worlds. Indeed, George Sachs was remarkable for another reason.
Towards the end of his medical dissertation, Sachs describes how certain sounds, words and ideas have colors that are not seen by the other people around him. In the alphabet, the letters A and E are both shades of red; I is white, as are M and N; D is yellow; S is dark blue and so on. Of the numbers, 1 is white, 2 is of uncertain color, 3 is ash color, 4 is red and so on. Groups of numbers took on the color of the last digit. So, for example, 34 and 24 are the color of four (=red) and 35 and 25 are the color of five (=yellow). Musical sounds also had colors, as did certain words such as city names and days of the week. The colors for these words did not always correspond to the colors of the letters that comprise them.
There is a certain irony in the fact that someone with such rich experiences of color was, in terms of physical appearance, devoid of color. Sachsâ description is now recognized as the first medical account of the condition that we now know as synesthesia. I use the term âconditionâ deliberately but with qualification. Synesthesia is a real phenomenon with a biological basis that is found in a minority of people. It is not, however, a disorder. Nor is it a condition that requires treatment or sympathy. It is not, with the benefit of hindsight, associated with albinism (most synesthetes are not albinos). In fact, synesthesia is a condition that many people aspire to. Many artists seek to recreate it. Many cultures induce it using âmagicalâ plants to achieve spiritual enlightenment. Having synesthesia may also lead to certain benefits in everyday life, such as to oneâs memory. This book tells the story of synesthesia and, in so doing, reveals important conclusions concerning how all of our brains create sensory experiences. How is it possible to experience color when there is no color there? What makes people with synesthesia different? Why might all babies be synesthetic? Why might sensory mixing be an important feature of all brains, whether synesthetic or not? Before going on to consider these questions, the first question that needs to be tackled is: what is synesthesia?
Aliens in the family
People with synesthesia experience the ordinary world in extraordinary ways. Words can have tastes; names can have color; and the sequence of numbers may glide through space. Most definitions of synesthesia emphasize that there is an âextraâ sensation that is tagged on to what would normally be expected. For example, the sound of a flute may be a pastel lemon color. The sound is both heard and seen, but the color does not replace the heard soundâit coexists with it. This is why synesthesia is regarded as an extra sensation. Of course, for someone with synesthesia it doesnât feel like there is something extra because they have experienced the world this way for all their life. On the contrary, to a synesthete, it seems like there is something absent in the experiences of the people around them. To a synesthete, the color of a musical note may be just as much of a property of the music as the noteâs pitch and it doesnât feel, to them, like it is extra. The New York artist, Carol Steen, describes it in the following way:
There have been times when I have had one sensation such as toothache and observed the color of the pain, its taste and smell. All these synesthetic perceptions are aspects of one overall experience. I perceive them as related in the same way that windows, a door and front steps combine to become the image of a house.
Synesthetes can always vividly remember the moment in their life that they discovered that their way of experiencing the world was fundamentally different from the people around them. It is fascinating that this insight into their own experiences comes about only by contrasting it with what other people claim to experience. We just take our experiences for granted unless they are questioned in some way. When revealed to be different they can suddenly take on an importance that they never previously enjoyed. One of our research volunteers, Debbie, describes the moment that she inadvertently ventured out of the synesthesia closet.
I did not âdiscoverâ my synesthesia until I made a comment to my parents in my mid-twenties about a number. They were disputing some number that I had given them as a statistic and I said, by way of proof, that it could not have been seventy and had to be forty because it was a red number with a warm feel, and it was only halfway up the line to 100. It is extremely strange when the two people who know you better than anyone else regard you as though you were a complete alien. I then went on to describe how my numbers are not only colored, but also have very distinct patterns, as does time âthe time of day, days of the week, months within the year, and the years themselves.
Debbieâs drawing of her arrangement of numbers in space is shown in Figure 1. She is able to vary the perspective from which the pattern is observed, and this is illustrated by the different positions of the âlittle menâ. Each number would also have a color.
The colors that people experience tend to be very precise and they rarely seem to change over time. The synesthetic color doesnât override the true color. They seem to coexist and compete for attention. The colors and the experiences are very hard to put into words. Some synesthetes see the color as if it is on the page, but they still claim to be able to see that the text is truly black and white. Others describe the colors on some kind of âinner screenâ or perhaps floating in space at a fixed distance from their body. I received the following email from a synesthete, Rosemary, after she had listened to a radio documentary about synesthesia. This was one of the very first times that she had attempted to put her own experiences into words.
I read in black and white and THINK in color. The word âScotlandâ, for instance, is visible to my eyes as black, but is sensed as color in my head. I sense âScotlandâ spelled out in my head and the initial letter, S, lends an overall color to the feel of the whole word. In Scotlandâs case, gloss white, whilst the colors of the remaining seven letters are less significant and trail off into the distance. Iâve found it so hard to name colors. Words appear to be the wrong medium for what my brain âseesâ and âfeelsâ. For instance, after listening to your radio programme I at first thought of one of the brightest letters of the alphabetâthe letter Q. I asked myself âwhat color is Qâ? The first answer I came up with was that âQ was Q-coloredâ. I then realized this was nonsense, that Q wasnât a color; Q was an intense shade of pink. But âpinkâ sounded totally wrong to me as the word âpinkâ is composed of four colors beginning with brown (brown being the color of the letter P in âpinkâ). Next I wondered why Q was pink, and straight away got the answer that Q was pink because queens were pink, but immediately realized that this was nonsense tooââwhy are queens pink?â (the word âqueenâ is probably pink because the letter Q is pink, but that doesnât help either). Next, I thought of the letter S, which is gloss white and, asking myself âwhyâ, I assumed it was because snakes were white! Again, nonsense.
Synesthetes will often name their children to fit their synesthesia and choose their partners on this basis. This quote from one of our synesthetes, Sharon, is typical:
I was thinking the other day about my sonâs name [Adam]. It is red and yellow like mine. My husbandâs name is yellow. There are other names that I considered for my son but in the end I found I just couldnât have a child with a blue or purple name. It would feel like having a stranger in the family.
Synesthesia runs in families, so there is a strong likelihood that the child will have synesthesia themselves, but the child will probably associate a different color to the name, andâworse stillâthere is no guarantee that the color will be nice. One synesthete changed the spelling of her name from Sarah to Cera because the combination of colors in her original name clashed. Anne does not like the grayness of her name, as she explains:
I donât like my name because it is gray and olive green [a= gray but n=olive green], although the red-orange âeâ at the end makes it a little better. It still reminds me of those Spanish stuffed olives with a red-orange pimento. As the color of names go, it is not great.
When some people tell their parents that the number forty is âred with a warm feelâ, they get quite a different response to that experienced by Debbie. âNo! Forty is dark green with a brittle feelâ or âNo! Forty is a mixture of brilliant yellow for the 4 and translucent for the 0.â Although synesthesia runs in families, different family members disagree about what the âcorrectâ color is. George Sachsâ youngest sister had synesthesia too, and they disagreed over the colors. I have come across a set of identical twins, Jacqueline and Mary, with similar types of synesthesia but different sets of colors. They hadnât discussed it together as children and they didnât even realize that their way of seeing the world was special until they were in their early twenties when one of them happened to mention it to her mother who regarded it as âweirdâ. As Mary puts it:
I donât think I had even realized that my twin had it as well until then. We certainly argue about what colors certain letters areâI really canât imagine that she sees A as red, for example, whereas I see it as green. We have never come to blows over this. I suppose it is something that has made us a bit closer as it is something we share although in a slightly different way.
The first letters of their alphabets are given below.
| Jacqueline | Mary |
A | red | light green |
B | deep blue | indigo |
C | yellow | dark violet |
D | brown | dark brown |
E | blue/black | very dark turquoise |
F | pale mauve | lilac |
G | brown, slightly golden | reddish brown |
H | very pale blue | mustard yellow |
I | pale gray/white | black |
The fact that synesthesia runs in families doesnât automatically make it genetic. Money runs in families too, but wealth isnât genetic. However, there is scientific evidence of a genetic link to synesthesia. If synesthesia was inherited culturally by, for example, a mother teaching her daughter the colors of the alphabet then we would expect close agreement between mothersâ and daughtersâ colors, or between the colors of pairs of siblings. This is not found. Many family members arenât even aware of each otherâs synesthesia until after childhood. Colored alphabet books have also been suggested to be involved, but this doesnât explain why some people exposed to these books develop synesthesia and others do not. A large survey of synesthetes in Australia compared their colors with those found in colored alphabet books published between 1914 and 1986, and found no evidence of any correspondence. Although synesthetic experiences of color are particularly common, synesthesia can be found for the other senses and different types of synesthesia can co-occur with a family. James Wannerton, whom we will meet again in Chapter 2, experiences tastes for words. For example, âprofitâ tastes of unripe, pithy orange and âpeaceâ tastes of tomato soup. His sister reports a completely different type of synesthesia. When she reads, she experiences colored letters but the colors appear to be shining through the page. Synesthetes also often have more than one type of synesthesia. This suggests that different types of synesthesia have a common cause. Carol Steen, for example, experiences colors and other aspects of vision from touch, smell, sound, taste and pain. The albino, George Sachs, also had a wide variety of different types. All these facts argue against the view that synesthesia clusters in families because of word of mouth. But these facts also provide some clues as to how the gene is operating. The gene cannot determine exactly what types of synesthesia will be found in a person or what the precise associations will be (e.g. is âAâ red or light green?), but it does seem to increase the likelihood that they will develop some form of synesthesia.
Recent research has started collecting DNA samples from people with synesthesia and their relatives. Cells containing DNA can easily be obtained by gently rubbing the inside of oneâs cheek and the cell samples can be sent to laboratories in other parts of the world. Geneticists in Dublin (Ireland), Cambridge (UK) and Texas (USA) are currently hunting the synesthesia gene. This research has demonstrated, definitively, that there is a genetic component to synesthesia. However, it is looking less likely that there will be a single synesthesia gene. There may be several genes that are implicated in synesthesia. Perhaps different families have different synesthesia genes, or perhaps there are ten synesthesia genes and a person needs a certain number of these to become synesthetic. At present, we just donât know.
Is it possible to carry the synesthesia gene (or genes) but not be synesthetic? Yes. There are many cases of synesthesia, such as Debbieâs, in which neither parent has synesthesia. Unless there is an unusually high incidence of synesthesia in milkmen (or mailmen in the US), it is likely that one or both parents could carry the gene without having synesthesia. Synesthesia has also been noted to skip generations such that grandparents and grandchildren have it but the intermediate generation does not. There are even some genetically identical twins in which one twin has it and the other one does not. This doesnât disprove a genetic theory, but it does prove that genes arenât everything. It is possible that both twins could have the synesthesia gene but only one goes on to develop synesthesia. The real test of the genetic theory lies in the twinsâ offspring. If both twins have the gene, then the non-synesthetic twin should be just as likely to have synesthetic children as the synesthetic twin. This remains to be seen. Ultimately, any explanation of synesthesia will have to address genetic and non-genetic influences. All the descriptions, so far, speak of synesthesia as a lifelong condition that people are born with. However, there are other types of synesthesia that have different causes. In subsequent sections and chapters, I will discuss how synesthesia can sometimes be triggered by the onset of blindness or can be temporarily induced by drugs such as LSD. Both of the...