People usually assume that everyone else sees the world as they do, but this is not always
true. Carol Steen describes a visit to the dentist's office that very few people could take in
stride: "[The dentist] said, 'I can't really sat that you need a root canal in this tooth.' I said,
'This tooth is orange; please do it.'" (Carol Steen, "Synesthete Perspectives - Carol,"
online, 22 January 1999 page 2) When he tasted spearmint, Michael Watson described feeling "...a
round shape. There's a curve behind which I can reach, and it's very, very smooth. So it
must be made of glass, because what I'm feeling is this satiny smoothness." (Richard E.
Cytowic, The Man Who Tasted Shapes, (New York: Putnam, 1993) 122) Another woman
told Richard Cytowic, "Your beeper made me see three lightning bolts, brilliant red,
going up to the left." (Richard E. Cytowic, The Man Who Tasted Shapes, (New York:
Putnam, 1993) 47) Other people live in a world where numbers are colored, so the number
two might be white and zero green. (Carol Steen, "Synesthete Perspectives - Carol,"
online, 22 January 1999.) These combinations of the senses are called 'synesthesia'.
Synesthesia is a condition wherein a stimulus of one sense creates a response of
both that sense and a secondary one. The word comes from the Greek roots 'syn', meaning
union, and 'aisthesis', sensation. (Richard E. Cytowic, "Synesthesia and mapping of
subjective sensory dimensions," Neurology 39 (1989): 849-50.) Hence, it is the union of
the senses. "It is a normal brain process..." (Richard E. Cytowic, "Synesthesia:
Phenomenology And Neuropsychology," Psyche January 1995, online, 20 Jan. 1999.) that
synesthetes merely perceive before it is completed. Richard Cytowic writes that
"Synesthesia is currently defined by 5 criteria that separate it from imagery or artistic
fancy: (1) synesthesia is involuntary and cannot be suppressed; (2) the sensations appear
not in the mind, but are usually perceived externally as real; (3) the synesthetic sensations
are discrete... (4) they are highly memorable; (5) they are accompanied by strong emotion
and a sense of conviction." (Richard E. Cytowic, "Synesthesia and mapping of subjective
sensory dimensions," Neurology 39 (1989): 849-50.) The most recent definition of
synesthesia excludes the earlier concepts of imagining metaphors or envisioning pictures
while listening to music. Only things which are actually perceived fall within the
definition of synesthesiae, synesthetic experiences.
Different synesthetes may have different kinds of synesthesia. The specific types
are named with the sense stimulated by the environment first, then the sense which reacts.
According to this system, an auditory-visual synesthete sees lights, known as photisms,
when hearing sounds. It could also be called visual audition. Some people may have more
than one secondary sense triggered at once. One of these people described their
experience: "I heard the bell ringing...a small round object rolled before my eyes...my
fingers sensed something rough, like a rope...I experienced a taste of salt water...and
something white." Not all forms of synesthesia are as rare or overwhelming as this.
The most common form of synesthesia is auditory-visual, also known as colored
hearing. Synesthetes experiencing visual audition see lights known as photisms when they
hear certain sounds. The photisms are "generic...unelaborated: they see blobs, lines,
spirals, and lattice shapes," (Richard E. Cytowic, "Synesthesia: Phenomenology And
Neuropsychology," Psyche January 1995, online, 20 Jan. 1999.) rather than realistic
pictures. These shapes may "float on a 'screen'" in front of the synesthete's face. Different
types of music frequently have their own associated colors: "soft music is yellow" or
"blue music is loud, but not so loud as black music." (Horace B. English, "Colored
Hearing," Science 57 (1923): 444.)
A variation of auditory-visual synesthesia is another relatively common condition
in which letters, words, and numbers all have their own colors. To one synesthete,
'linguistics' is a "grayish-purple-blue" word and 'speech' is "yellowy and orange." (Karen
Chenausky, "Synesthete Perspectives - Karen," online, 22 January 1999.) "The
consonants are paler [than the vowels] and far more often gray..."
Pain can also produce secondary sensations. A gustatory-visual synesthete also
said that capsicum (a component of Mace) on his forehead "produced the same tactual
feeling as the taste of bitter." (June E. Downey, "A Case of Colored Gustation," American
Journal of Psychology 22 (1911): 531.) A woman who also experienced colored hearing
saw photisms "at the place where the pain was located." (Dudycha 58)
The stimuli which trigger synesthesiae depend on the individual
experiencing them. An auditory-visual synesthete will only experience synesthesiae when
hearing the sort of sounds which create photisms for them. Some people react only in
"circumstances that would promote a startle reaction to sound..." (Jacobs 215) The
triggers may be extremely specific. "Anne...saw colored shapes only in response to a
specific type of music, and not any other kinds of sound." (Richard E. Cytowic, The Man
Who Tasted Shapes, (New York: Putnam, 1993) 120.) Sean Day, writing about colored-
letter synesthesia, notes that "It is not at all uncommon for this type of synesthete to not
have the entire alphabet colored; for example, only the vowels may be colored..." (Sean
Day, "Trends in Colored Letter Synesthesia," Synesthesia List 31 May 1996, online, 21
January 1999.) These people are not constantly experiencing synesthesiae.
Synesthesiae also differ from person to person. Everyone who sees colored letters
does not share the same alphabet. One person may think that "U" is blue, while another
may see it as white. (Sean Day, "Trends in Colored Letter Synesthesia," Synesthesia List
31 May 1996, online, 21 January 1999.) Each feels that "my colors are right and other
people's are wrong." (Karen Chenausky, "An Extra Way of Perceiving the World," online,
2 February 1999.) The inconsistency of experiences have confused scientists in the past,
as synesthetes do not support each other's subjective perceptions.
There is no clear cause of synesthesia. Some tests have shown decreased blood
flow in the cortex of synesthetes' brains during synesthesiae, (Richard E. Cytowic, The
Man Who Tasted Shapes, (New York: Putnam, 1993) 150-1.) supporting the hypothesis
that "synesthesia does not occur in the cortex." Jacobs hypothesizes that auditory-visual
synesthesia could be a manifestation of a disease of the central nervous system. He bases
this on patients who had suffered vision loss because of lesions on the front portions of
their visual pathways, but experience photisms caused by sound. (Jacobs, A-V)
The causes of temporary synesthesia are easier to discern, as it ends when they are
removed. In addition to the rare people who are born with the condition, others may
experience it in rare circumstances. It occurs during less than 10% of a certain type of
epileptic seizure in people who are not synesthetic before or after the seizure. (Richard E.
Cytowic, "Synesthesia and mapping of subjective sensory dimensions," Neurology 39
(1989): 849-50.) Hallucinogens and sensory deprivation infrequently induce synesthesia
wealth affect the subject. Usually unaffected people may experience auditory-visual
synesthesia under hypnosis. (Vike 681) Gross brainstem lesions may impart temporary
synesthesia. In one patient, the removal of a cystic tumor on the brainstem ended the
patient's synesthesia. (Richard E. Cytowic, "Synesthesia and mapping of subjective
sensory dimensions," Neurology 39 (1989): 849-50.) One man's photisms disappeared
after the removal of a large mass on his medial temporal lobe. (Vike 680)
There is little consensus on the incidence of synesthesia because "...without a
doubt, there are individuals who have some form of synesthesia, but who have never
noted the fact that their experiences are different from those of other individuals."
(Dudchya 57) They may also understand their condition, but be cautious of sharing
because many people would misunderstand. One boy learned this lesson when he drew
others to smell a maple tree, and they responded by saying, "Don't be silly. There's
nothing there." (Richard E. Cytowic, The Man Who Tasted Shapes, (New York: Putnam,
1993) 44.)
When synesthetes discover that other people experience what they do, they may
tell their friends, "See! This is me! I told you it's real. I'm not nuts!" (Richard E. Cytowic,
The Man Who Tasted Shapes, (New York: Putnam, 1993) 112.) This may not happen for
every synesthete; Because of the obscurity, it is difficult to determine the actual incidence
of synesthesia. Estimates range from one in twenty-five thousand (Richard E. Cytowic,
"Synesthesia: Phenomenology And Neuropsychology," Psyche January 1995, online, 20
Jan. 1999.) to "9 to 15 per cent. of adults and...25 per cent. of adolescents." (Mudge, p
342)
Life-long synesthetes "appear normal in every sense, have normal neurological
exams, and are of normal intelligence." (Richard E. Cytowic, "Synesthesia and mapping
of subjective sensory dimensions," Neurology 39 (1989): 850.) "The only way for
synesthetes to share their perceptions is to tell us about them." (Richard E. Cytowic, The
Man Who Tasted Shapes, (New York: Putnam, 1993) 121.)
When they first hear about synesthesia, most people think about what they would
experience if they had it. However, synesthetes have had their synesthesiae 'as long as
they can remember.' By the time they are adults, synesthetes have generally learned to
work with their overlapping senses. When they first hear about synesthesia, most people
think about what they would experience if they had it. However, synesthetes have had
their synesthesiae 'as long as they can remember.' They have had time to adjust to it. They
generally have better memories than unaffected people. These are aided by their
synesthesiae. Synesthetic experiences are memorable and, in the minds of the synesthetes,
are connected to the sensations which caused the synesthesiae. One man could remember
that chicken he had served seven years before "was indeed uniformly round and it needed
more points." He remembered the shape first, and then the anecdote.(Richard E. Cytowic,
The Man Who Tasted Shapes, (New York: Putnam, 1993) 129.) The tendency for the
synesthesiae to trigger the memory is also demonstrated in the statement "I remember the
number 2 because it's white." (Richard E. Cytowic, "Synesthesia: Phenomenology And
Neuropsychology," Psyche January 1995, online, 20 Jan. 1999.) In a case of colored
gustation, recognition of flavors was more certain with the "taste qualities which are most
unambiguously colored." (June E. Downey, "A Case of Colored Gustation," American
Journal of Psychology 22 (1911): 530.)
In the same case, though, the man could not determine that "bitter...is characteristic of the
taste of unsweetened chocolate or ground coffee," because they did not produce the same
color as quinine. (June E. Downey, "A Case of Colored Gustation," American Journal of
Psychology 22 (1911): 531.) He was also "unable to distinguish between strong solutions
of red pepper and of quinine, because both produced the same 'feel' upon the tongue, and
both were accompanied by the same color." (June E. Downey, "A Case of Colored
Gustation," American Journal of Psychology 22 (1911): 531.) With anise, "the brilliant
black color...appeared...to serve as a mark of identification." The recognition of the color
rather than the flavor confused him rather than aiding him: "Sarsaparilla syrup, which
likewise induced black, was also identified as anise."
The experiences may also be distracting, as in the case of (Luria) who said, "What
strikes me first is the color of someone's voice...Sometimes I get so interested in the
voice, I can't understand what's being said." (Richard E. Cytowic, "Synesthesia and
mapping of subjective sensory dimensions," Neurology 39 (1989): 849-50.) They may
also react to the world based on their synesthesia. Karen described 'not wanting to do
something that looked like speech does,' but over time 'her fondness for the colors
changed,' though the colors of the words themselves did not. (Karen Chenausky,
"Synesthete Perspectives - Karen," online, 22 January 1999.)
One of Cytowic's criteria for diagnosing a synesthete is the feeling that the
synesthesiae are real. Synesthetes know that they do not imagine the sensations they feel.
These sensations are not detailed. They "don't see pastoral landscapes while listening to
Beethoven, nor taste clam chowder when touching wood," (Richard E. Cytowic,
"Synesthesia and mapping of subjective sensory dimensions," Neurology 39 (1989): 849-
50.), instead, they see abstract geometrical figures or taste salt, sweet, sour, or bitter.
"What synesthetes actually sense is elementary." (Richard E. Cytowic, The Man Who
Tasted Shapes, (New York: Putnam, 1993) 120.)
Cytowic says that synesthetes often have trouble working with numbers and have
a poor sense of spatial relationships. They may also have confusion between right and left
and a poor sense of direction. It is difficult to judge the sensitivity of their senses because
their perceptions may rely upon their synesthesiae. (June E. Downey, "A Case of Colored
Gustation," American Journal of Psychology 22 (1911): 529-30.)
There has been little discussion of treatment of synesthetes. Stimulants can reduce
the immediacy of some peoples' synesthesiae temporarily because they "turn up the
cortex." This also decreases activity in the limbic brain, the site of synesthesia. This can
be frightening for people who have always experienced secondary sensations. One man,
when his synesthesiae were attenuated by amphetamines, asked the researcher, "What
have you done to me?" "For all its strangeness, his synesthesia had been familiar."
(Richard E. Cytowic, The Man Who Tasted Shapes, (New York: Putnam, 1993) 120.)
The oddity of synesthesia is subjective, just as the experiences themselves are.
People may use their synesthesiae in their everyday lives, or they may simply
ignore it as a useless distraction.
Look at the Foot Note information.
Look at the Bibliography.
This belongs to Laura Waterstripe, so keep yer grubby paws off.