How someone with synesthesia might
perceive certain letters and numbers.
)—from the Ancient Greek (syn),
"together," and (aisthēsis), "sensation
"—is a neurologically based
phenomenon in which stimulation of one sensory or cognitive pathway
leads to automatic, involuntary experiences in a second sensory or
cognitive pathway. People who report such experiences are known as
In one common form of synesthesia, known as grapheme → color synesthesia
color-graphemic synesthesia, letter
are perceived as inherently colored,
while in ordinal
, numbers, days of the week and
months of the year evoke personalities. In spatial-sequence, or
synesthesia, numbers, months
of the year, and/or days of the week elicit precise locations in
space (for example, 1980 may be "farther away" than 1990), or may
have a (three-dimensional) view of a year as a map (clockwise or
counterclockwise). Yet another recently identified type, visual
motion → sound synesthesia, involves hearing sounds in response to
visual motion and flicker. Over 60 types of synesthesia have been
reported by people, but only a fraction have been evaluated by
scientific research. Even within one type, synesthetic perceptions
vary in intensity and people vary in awareness of their synesthetic
While cross-sensory metaphors
shirt," "bitter wind" or "prickly laugh") are sometimes described
as "synesthetic," true neurological synesthesia is involuntary. It
is estimated that synesthesia could possibly be as prevalent as 1
in 23 persons across its range of variants. Synesthesia runs
strongly in families, but the precise mode of inheritance has yet
to be ascertained. Synesthesia is also sometimes reported by
individuals under the influence of psychedelic drugs
, after a stroke
, during a temporal lobe epilepsy
seizure, or as
a result of blindness
. Synesthesia that arises from such
non-genetic events is referred to as "adventitious synesthesia" to
distinguish it from the more common congenital
synesthesia. Adventitious synesthesia involving drugs or stroke
(but not blindness or deafness) apparently only involves sensory
linkings such as sound → vision or touch → hearing; there are few,
if any, reported cases involving culture-based, learned sets such
, days of the week, or months of the
Although synesthesia was the topic of intensive scientific
investigation in the late 1800s and early 1900s, it was largely
abandoned by scientific research in the mid-20th century, and has
only recently been rediscovered by modern researchers. Psychological
research has demonstrated that
synesthetic experiences can have measurable behavioral
consequences, while functional
studies have identified differences in patterns of
brain activation. Many people with synesthesia use their
experiences to aid in their creative process, and many
non-synesthetes have attempted to create works of art that may
capture what it is like to experience synesthesia. Psychologists
and neuroscientists study synesthesia not only for its inherent
interest, but also for the insights it may give into cognitive and
perceptual processes that occur in synesthetes and non-synesthetes
Although sometimes spoken of as a "neurological condition"
synesthesia is not listed in either the DSM-IV
or the ICD
since it most often does not interfere with normal daily
functioning. It has, however, appeared for many years in both
Dorland's and Steadman's medical dictionaries. Indeed most
synesthetes report that their experiences are neutral, or even
pleasant. Rather, like color
or perfect pitch
synesthesia is a difference in perceptual experience and the term
"neurological" simply reflects the brain basis of this perceptual
difference (see below
for associated cognitive traits).
It was once assumed that synesthetic experiences were entirely
different from synesthete to synesthete, but recent research has
shown that there are underlying similarities that can be observed
when large numbers of synesthetes are examined together. For
example, sound-color synesthetes, as a group, tend to see lighter
colors for higher sounds and grapheme-color synesthetes, as a
group, share significant preferences for the color of each letter
(e.g., A tends to be red; O tends to be white or black; S tends to
be yellow etc.,). Nonetheless, there are a great number of types of
synesthesia, and within each type, individuals can report differing
triggers for their sensations, and differing intensities of
experiences. This variety means that defining synesthesia in an
individual is difficult, and indeed, the majority of synesthetes
are completely unaware that their experiences have a name. However,
despite the differences between individuals, there are a few common
elements that define a true synesthetic experience.
Neurologist Richard Cytowic
identifies the following diagnostic criteria of synesthesia:
- Synesthesia is involuntary and automatic.
- Synesthetic perceptions are spatially extended, meaning they
often have a sense of "location." For example, synesthetes speak of
"looking at" or "going to" a particular place to attend to the
- Synesthetic percepts are consistent and generic (i.e., simple
rather than pictorial).
- Synesthesia is highly memorable.
- Synesthesia is laden with affect.
Cytowic's early cases included individuals whose synesthesia was
frankly projected outside the body (e.g., on a "screen" in front of
one's face). Later research showed that such stark externalization
occurs in a minority of synesthetes. Refining this concept, Cytowic
and Eagleman differentiate between "localizers" and
"non-localizers" to distinguish those synesthetes whose perceptions
have a definite sense of spatial quality.
Synesthetes often report that they were unaware their experiences
were unusual until they realized other people did not have them,
while others report feeling as if they had been keeping a secret
their entire lives, as has been documented in interviews with
synesthetes on how they discovered synesthesia in their childhood.
The automatic and ineffable nature of a synesthetic experience
means that the pairing may not seem out of the ordinary. This
involuntary and consistent nature helps define synesthesia as a
real experience. Most synesthetes report that their experiences are
pleasant or neutral, although, in rare cases, synesthetes report
that their experiences can lead to a degree of sensory overload
Though often stereotyped in the popular media as a medical
condition or neurological aberration, many synesthetes themselves
do not perceive their synesthetic experiences as a handicap. To the
contrary, most report it as a gift—an additional "hidden"
sense—something they would not want to miss. Most synesthetes have
become aware of their "hidden" and different way of perceiving in
their childhood. Some have learned how to apply this gift in daily
life and work. Synesthetes have used their gift in memorizing names
and telephone numbers, mental arithmetic, but also in more complex
creative activities like producing visual art, music, and
Despite the commonalities which permit definition of the broad
phenomenon of synesthesia, individual experiences vary in numerous
ways. This variability was first noticed early on in synesthesia
research but has only recently come to be re-appreciated by modern
researchers. Some grapheme → color synesthetes report that the
colors seem to be "projected" out into the world (called
"projectors"), while most report that the colors are experienced in
their "mind's eye" (called "associators"). It is estimated that
approximately one or two per hundred grapheme-color synesthetes are
projectors; the rest are associators.
Additionally, some grapheme → color synesthetes report that they
experience their colors strongly, and show perceptual enhancement
on the perceptual tasks described below, while others (perhaps the
majority) do not, perhaps due to differences in the stage at which
colors are evoked. Some synesthetes report that vowels
are more strongly colored, while for others
are more strongly colored. In
summary, self reports, autobiographical notes by synesthetes and
interviews show a large variety in types of synesthesia, intensity
of the synesthetic perceptions, awareness of the difference in
perceiving the physical world from other people, the way they
creatively use their synesthesia in work and daily life. The
descriptions below give some examples of synesthetes' experiences,
which have been experimentally tested, but do not exhaust their
Synesthesia can occur between nearly any two senses or perceptual
modes. Given the large number of forms of synesthesia, researchers
have adopted a convention of indicating the type of synesthesia by
using the following notation x → y, where x is the "inducer" or
trigger experience, and y is the "concurrent" or additional
experience. For example, perceiving letters and numbers
(collectively called graphemes
) as colored
would be indicated as grapheme → color synesthesia. Similarly, when
synesthetes see colors and movement as a result of hearing musical
tones, it would be indicated as tone → (color, movement)
While nearly every logically possible combination of experiences
can occur, several types are more common than others.
Grapheme → color synesthesia
In one of the most common forms of synesthesia, grapheme → color
synesthesia, individual letters of the alphabet and numbers
(collectively referred to as graphemes
are "shaded" or "tinged" with a color
different individuals usually do not report the same colors for all
letters and numbers, studies with large numbers of synesthetes find
some commonalities across letters (e.g., A is likely to be
As a child, Pat Duffy
Dad, "I realized that to make an R all I had to do was first write
a P and draw a line down from its loop. And I was so surprised that
I could turn a yellow letter into an orange letter just by adding a
line." Another grapheme synesthete says, "When I read, about five
words around the exact one I'm reading are in color. It's also the
only way I can spell. In elementary school I remember knowing how
to spell the word 'priority' [with an "i" rather than an "e"]
because ... an 'e' was out of place in that word because e's were
yellow and didn't fit."
Sound → color synesthesia
Cytowic calls sound → color synesthesia "something like fireworks":
voice, music, and assorted environmental sounds such as clattering
dishes or dog barks trigger color and simple shapes that arise,
move around, and then fade when the sound stimulus ends. For some,
the stimulus type is limited (e.g., music only, or even just a
specific musical key); for others, a wide variety of sounds
Sound often changes the perceived hue, brightness, scintillation,
and directional movement. Some individuals see music on a "screen"
in front of their face. Deni Simon, for whom music produces waving
lines "like oscilloscope configurations—lines moving in color,
often metallic with height, width and, most importantly, depth. My
favorite music has lines that extend horizontally beyond the
Though individuals hardly ever agree on what color a given sound is
on the colors of music keys), synesthetes show the same trends as
non-synesthetes do. For example, both groups say that louder tones
are brighter than dull, soft tones, where as higher tones are
smaller and lighter than low ones. Low tones are both larger and
darker than high ones.
Number form synesthesia
A number form is a mental map of numbers, which automatically and
involuntarily appears whenever someone who experiences number-forms
thinks of numbers. Number forms were first documented and named by
in "The Visions of
Sane Persons". Later research has identified them as a type of
synesthesia. In particular, it has been suggested that number-forms
are a result of "cross-activation" between regions of the parietal lobe
that are involved in numerical cognition
and spatial cognition. In addition to
its interest as a form of synesthesia, researchers in numerical
cognition have begun to explore this form of synesthesia for the
insights that it may provide into the neural mechanisms of
numerical-spatial associations present unconsciously in
Ordinal-linguistic personification (OLP, or personification for
short) is a form of synesthesia in which ordered sequences, such as
are associated with
personalities. Although this form of synesthesia was documented as
early as the 1890s modern research has, until recently, paid little
attention to this form.
For example, one synesthete says, "T’s are generally crabbed,
ungenerous creatures. U is a soulless sort of thing. 4 is honest,
but… 3 I cannot trust… 9 is dark, a gentleman, tall and graceful,
but politic under his suavity." Likewise, Cytowic's subject MT
says, "I [is] a bit of a worrier at times, although easy-going; J
[is] male; appearing jocular, but with strength of character; K
[is] female; quiet, responsible...."
For some people in addition to numbers and other ordinal sequences,
objects are sometimes imbued with a sense of personality. Recent
research has begun to show that alphanumeric personification
co-varies with other forms of synesthesia, and is consistent and
automatic, as required to be considered a form of
Lexical → gustatory synesthesia
In the rare lexical → gustatory synesthesia, individual words and
of spoken language evoke taste
sensations in the mouth. According to James Wannerton
, "Whenever I hear, read, or
articulate (inner speech) words or word sounds, I experience an
immediate and involuntary taste sensation on my tongue. These very
specific taste associations never change and have remained the same
for as long as I can remember."
Jamie Ward and Julia Simner have extensively studied this form of
synesthesia, and have found that the synesthetic associations are
constrained by early food experiences. For example, James Wannerton
has no synesthetic experiences of coffee or curry, even though he
consumes them regularly as an adult. Conversely, he tastes certain
breakfast cereals and candies that are no longer sold.
Additionally, these early food experiences are often paired with
tastes based on the phonemes in the name of the word (e.g., /I/,
/n/ and /s/ trigger James Wannerton’s taste of mince) although
others have less obvious roots (e.g., /f/ triggers sherbet). To
show that phonemes, rather than graphemes are the critical triggers
of tastes, Ward and Simner showed that, for James Wannerton, the
taste of egg is associated to the phoneme /k/, whether spelled with
a "c" (e.g., accept), "k" (e.g., York), "ck" (e.g., chuck) or "x"
(e.g., fax). Another source of tastes comes from semantic
influences, so that food names tend to taste of the food they
match, and the word "blue" tastes "inky."
The interest in colored hearing dates back to Greek antiquity, when
philosophers asked if the color (chroia
, what we now call
timbre) of music was a quantifiable quality. Isaac Newton proposed
that musical tones and color tones shared common frequencies, as
did Goethe in his book, "Theory of Color." Despite this idea being
false, there is a long history of building color organs such as the
clavier à lumières
which to perform colored music in concert halls
The first medical description of colored hearing is in a German
1812 thesis. The father of psychophysics
, Gustav Fechner
reported the first empirical
survey of colored letter photisms among 73 synesthetes in 1871,
followed in the 1880s by Francis
. Research into synesthesia proceeded briskly in several
countries, but due to the difficulties in measuring subjective
experiences and the rise of behaviorism
which made the study of any
subjective experience taboo,
synesthesia faded into scientific oblivion between 1930 and
As the 1980s cognitive
began to make inquiry into internal subjective
states respectable again, scientists once again looked to
synesthesia. Led in the United States by Larry Marks and Richard Cytowic
, and later in England by
and Jeffrey Gray
, research explored the
reality, consistency, and frequency of synesthetic experiences. In
the late 1990s, the focus settled on grapheme → color synesthesia,
one of the most common and easily studied types. Synesthesia is now
the topic of scientific books and papers, Ph.D. theses, documentary
films, and even novels.
Since the rise of the Internet in the 1990, synesthetes began
contacting one another and creating Web sites devoted to the
condition. These early grew into international organizations such
as the American
, the UK Synaesthesia Association
, the German Synesthesia Association and the
Netherlands Synesthesia Web Community.
Prevalence and genetic basis
Early estimates of prevalence varied widely (from 1 in 20 to 1 in
20,000). These studies all had the methodological shortcoming of
relying on self-selection
individuals reporting their experience to investigators. Random
population studies later determined that 1 in 23 individuals have
some kind of synesthesia, while 1 in 90 have colored graphemes.
Colored days of the week and colored graphemes are the most common
Many studies noted that synesthesia runs in families, consistent
with a genetic origin for the condition. Francis Galton
's 1880 report noted a familial
component. Studies from the 1990s that noted a much higher
prevalence in women than men (up to 6:1) most likely suffered from
a sampling bias
due to the fact that
women are more likely to self-disclose than men. More recent random
samples find an equal sex ratio of 1.1:1.
At first, the observed patterns of inheritance were consistent with
mode of inheritance because
there had been no verified reports of father-to-son transmission,
whereas father-to-daughter, mother-to-son and mother-to-daughter
transmission were readily observed However, the first genome-wide association study
failed to find X-linkage, and furthermore verified two cases of
Suggestive of incomplete gene penetrance
is the situation of identical twins in which only one member of the
pair is synesthetic, and the observation that synesthesia can skip
generations within a family.. It is furthermore common for family
members to experience different types of synesthesia, suggesting
that the gene(s) involved do not lead to invariably specific types
of synesthesia. Developmental factors such as gene expression
and environment must also
play a role in determining which types of synesthesia an individual
has (for example, children must interact with culturally-learned
artifacts such as alphabets and food names).
Reaction times for answers that are
congruent with a synesthete’s automatic colors are faster than
those whose answer is incongruent.
Synesthesia is hard to fake, and easy to prove as a genuine
perception. The simplest approach is test-retest reliability over
long periods of time, where synesthetes consistently score much
higher—around 90% after years, compared to 30-40% after just a
month in non-synesthetes even when they are warned they will be
retested—using stimuli of color names, color chips, or a
computer-screen color picker providing 16.7 million choices.
Modified versions of the Stroop effect
are popular. In the standard paradigm, it is harder to name the ink
color of the word "red," for example, when it is printed in blue
ink than when the ink is red. Similarly, if a grapheme → color
synesthete is shown the digit 4 (which he sees as red, say) in blue
ink, he is slower to name the ink color than when it is printed in
red. He sees the blue ink, but the same sort of conflict
responsible for the standard Stroop effect occurs between the ink
color and the automatic
color of the grapheme. The conflict is strongest when the ink color
is the opponent color
synesthetic one (e.g., red vs. green), indicating that synesthetic
color perception uses the same mechanism as the perception of real
Cross-sensory Stroop tests are possible: for example, a music →
color synesthete must name a red swatch while listening to a sound
that produces a blue sensation, or a musical key → taste synesthete
must identify a bitter taste while hearing a musical interval that
tastes sweet . Likewise, Stroop tests work even in those for whom
merely thinking about a numeral
elicits color. Take a
person who sees 7 as yellow and 9 as blue, and make the task one of
having to say a math solution out loud followed by naming a color
square. In the illustration, having to answer “7” and then “yellow”
is congruent with the subject’s synesthesia, which unconsciously
primes him to respond faster than controls. The automatic blueness
of 9, however, interferes with naming the green square, slowing him
down compared to controls.
Synesthetic colors can also improve performance
synesthetes. Inspired by tests for color
and Hubbard presented
synesthetes and non-synesthetes with a matrix of 5s in which
embedded 2s formed a hidden pattern such as a square, diamond,
rectangle or triangle.. For someone who sees 2s as red and 5s as
green, for example, synesthetic colors help zero in on the embedded
figure. Subsequent careful studies have found substantial
among synesthetes in their ability to do this. It
certainly does not happen instantaneously; while synesthesia is
evoked very early in perceptual processing, it does not occur prior
Possible neural basis
Regions thought to be cross-activated
in grapheme-color synesthesia (green=grapheme recognition area,
red=V4 color area).
Dedicated regions of the brain are specialized for given functions.
Increased cross-talk between regions specialized for different
functions may account for the many types of synesthesia. For
example, the additive experience of seeing color when looking at
graphemes might be due to cross-activation of the
grapheme-recognition area and the color area called V4
(see figure). One line of thinking is
that a failure to prune
that are normally formed in great excess during the first few years
of life may cause such cross-activation.
An alternate possibility is disinhibited feedback, or a reduction
in the amount of inhibition along normally existing feedback
pathways. Normally, excitation and inhibition are balanced.
However, if normal feedback were not inhibited as usual, then
signals feeding back from late stages of multi-sensory processing
might influence earlier stages such that tones could activate
vision. Cytowic & Eagleman find support for the disinhibition
idea in the so-called acquired forms of synesthesia that occur in
non-synesthetes under certain conditions: Temporal lobe epilepsy
, head trauma,
stroke, and brain tumors. It can likewise occur during stages of
meditation, deep concentration, sensory deprivation
, or with use of
and certain prescription medications.
studies using PET
demonstrate significant differences between the brains of
synesthetes and non-synesthetes. fMRI shows V4 activation in both
word → color and grapheme → color synesthetes. Diffusion tensor imaging
visualization of white matter
pathways in the intact brain. This method demonstrates increased
connectivity in fusiform gyrus
synesthetes. The degree of white matter connectivity in the
fusiform gyrus correlates with the intensity of the synesthetic
Associated cognitive traits
Little is known about what, if any, cognitive traits might be
associated with synesthesia. As early as 1980, Richard Cytowic
first noted mild
difficulties in left-right
, and sense of
direction. These observations await large-scale confirmation. What
has been confirmed is elevated, sometimes photographic
, memory. When asked, "What good
is it?" synesthetes say, "It helps me remember." Indeed, it was
reading Alexander Luria
's 1968 book
The Mind of a Mnemonist
that alerted Cytowic to the link
between synesthesia and elevated memory: Luria's subject had a
5-fold synesthesia that gave him extra hooks on which to hang and
remember numerous facts.
Autism and epilepsy occur with synesthesia more often than chance
predicts. Daniel Tammet
, the savant
who set a European record for reciting the digits of pi
, has all three conditions indicating that they might
share an underlying genetic cause. Synesthesia has so far been
linked to a region on chromosome 2
is associated with autism and epilepsy.
Synesthetes are likely to participate in creative
activities. Individual development of
perceptual and cognitive skills, and one's cultural environment
likely determine the variety in awareness and practical use of
synesthetic skills These are major topics of ongoing
Links with other areas of study
Researchers study synesthesia not only because it is inherently
interesting, but also because studying it can offer insights into
other questions, such as how the brain combines information from
different sensory modalities, referred to as crossmodal
perception and multisensory integration
Booba and Kiki shapes
An example of this is the bouba/kiki
. In an experiment first designed by Wolfgang Köhler
, people are asked to
choose which of two shapes is named bouba
95% to 98% of people choose kiki
angular shape and bouba
for the rounded one. Individuals on the
island of Tenerife showed a
similar preference between shapes called takete and
Even 2.5 year-old children (too young to
read) show this effect.
Ramachandran and Hubbard suggest the kiki/bouba effect has
implications for the evolution of language, because the naming of
objects is not completely arbitrary. The rounded shape may
intuitively be named bouba
because the mouth makes a more
rounded shape to produce that sound, while a more taut, angular
mouth shape is needed to articulate kiki
. The sound of K
is also harder and more forceful than that of B. Such
"synesthesia-like mappings" suggest that this effect might be the
neurological basis for sound
, in which sounds are non-arbitrarily mapped to
objects and actions in the world.
Given synesthetes' extraordinary conscious experiences, researchers
hope that their study will provide better understanding of consciousness
and its neural correlates
, meaning what the brain
mechanisms that make us conscious might be. In particular,
synesthesia might be relevant to the philosophical
problem of qualia
, given that synesthetes experience extra
qualia (e.g., a colored sound).
Vision by Carol Steen; Oil on
Paper; 15x12-3/4" 1996.
A representation of a synesthetic photism experienced during
The word "synesthesia" has been used for 300 years to describe very
different things, from poetry and metaphor to deliberately
contrived mixed-media applications such as son et lumière
shows or odorama
. It is crucial to separate artists
using synesthesia as an intellectual
—pseudo-synesthetes such as Georgia O'Keeffe
who used such titles as
"Music-Pink and Blue"—from those who had the genuine perceptual
variety, such as Wassily Kandinsky
or Olivier Messiaen
Synesthetic art historically refers to multi-sensory experiments in
the genres of visual music
, music visualization
, audiovisual art
, abstract film
, and intermedia
. Distinct from neuroscience, the
concept of synesthesia in the arts is regarded as the simultaneous
perception of multiple stimuli in one gestalt
experience. Only recently can
science verify and study synesthesia in artists; for deceased
artists, one must interpret (auto)biographical information.
Synesthetic art can refer to either art created by synesthetes or
art that attempts to convey the synesthetic experience. It is an
attempt to understand the relation between the experiences of born
synesthetes, non-synesthetes, and an appreciation of such art by
both groups. These distinctions are not mutually exclusive given
that art by a synesthete might also evoke synesthesia-like
experiences in the viewer.
Contemporary synesthetic artists such as Carol Steen and Marcia
Smilack have described in detail how they use their synesthesia to
create their artworks. They demonstrate the complex interplay
between personal experience and artistic creation.
Synesthesia has been a source of inspiration for artists,
composers, poets, novelists, and digital artists. Nabokov
writes explicitly about synesthesia
in several novels. Kandinsky
synesthete) and Mondrian (not a synesthete) both experimented with
image-music correspondences in their paintings. Scriabin
composed color music that was
deliberately contrived and based on the circle of fifths
, whereas Messiaen
invented a new method of
composition (the modes of
) to specifically render his
bi-directional sound-color synesthesia. For example, the red
rocks of Bryce Canyon are depicted in his symphony Des canyons aux étoiles
("From the Canyons to the Stars").
New art movements such as
literary symbolism, non-figurative art, and visual music have
profited from experiments with synesthetic perception and
contributed to the public awareness of synesthetic and
multi-sensory ways of perceiving.
Synesthesia is sometimes used as a plot device or way of developing
a character's inner life. Author and synesthete Pat Duffy
describes four ways in which
synesthetic characters have been used in modern fiction.
- Synesthesia as Romantic ideal: in
which the condition illustrates the Romantic ideal of transcending
one's experience of the world. Books in this category include
The Gift by
- Synesthesia as pathology: in which the trait is pathological.
Books in this category include The Whole World Over by
- Synesthesia as Romantic pathology: in which synesthesia is
pathological but also provides an avenue to the Romantic ideal of
transcending quotidian experience. Books in this category include
Holly Payne’s, The Sound of Blue.
- Synesthesia as psychological health and balance: Painting
Ruby Tuesday by Jane Yardley, and
A Mango-Shaped Space
by Wendy Mass.
Many literary depictions of synesthesia are not accurate.
Some say more about an author's interpretation
synesthesia than the phenomenon itself.
In Mary Shelley
, the creature describes being
in a synesthetic state early in his existence even though the
phenomenon was not well documented when the book was written.
People with synesthesia
Determining synesthesia from the historical record is fraught with
error unless (auto)biographical sources explicitly give convincing
Famous synesthetes include David
, who perceives music as color, shape, and
configuration, and who uses these perceptions when painting opera
stage sets but not while creating his other artworks. Russian
painter Wassily Kandinsky
four senses: color, hearing, touch, and smell. Vladimir Nabokov
grapheme-color synesthesia at length in his autobiography,
and portrays it
in some of his characters. Composers include Duke Ellington
, and Olivier
, whose three types of complex colors are rendered
explicitly in musical chord structures that he invented. Physicist
colored equations in his autobiography, What Do You Care What
Other People Think?
Other notable synesthetes include
musicians John Mayer
and Patrick Stump
; actress Stephanie Carswell
; electronic musician
Richard D. James aka Aphex Twin
claims to be inspired by lucid dreams
well as music); and classical pianist Hélène Grimaud
. Although it has
been verified, Pharrell
of the hip-hop Neptunes
claims to experience
synesthesia, and to have used it as the basis of the album Seeing Sounds
Some artists frequently mentioned as synesthetes did not in fact
have the condition. Alexander
's 1911 Prometheus
, for example,
is a deliberate contrivance whose color choices are based on the
circle of fifths
and appear to have
been taken from Madame Blavatsky
The musical score has a separate staff marked luce
"notes" are played on a color organ
Technical reviews appear in period volumes of Scientific
French poets Arthur Rimbaud
synesthetic experience but there is no evidence they were
synesthetes themselves. Baudelaire's 1857 ( text available here
) introduced the notion that the
senses can and should intermingle. Baudelaire participated in a
hashish experiment by psychiatrist Jacques-Joseph Moreau
, and became
interested in how the senses might correspond. Rimbaud later wrote
(1871) ( text available here
), which was perhaps more important
than in popularizing synesthesia, although he later boasted
"J'inventais la couleur des voyelles!"
[I invented the
colors of the vowels!].
, synesthete and the President of the American Synesthesia
, maintains a list of famous synesthetes,
pseudosynesthetes, and non-synesthetes who used synesthesia in
their art or music.
- Day, Sean, Types of synesthesia. (2009) Types of synesthesia.
Online: http://home.comcast.net/~sean.day/html/types.htm, accessed
18 February 2009.
- Campen, Cretien van (2009) "The Hidden Sense: On Becoming Aware
of Synesthesia" TECCOGS, vol. 1, pp. 1-13.
- Dittmar, A. (Ed.) (2007) Synästhesien. Roter Faden durchs
Leben? Essen, Verlag Die Blaue Eule.
- Gage, J. Colour and Culture. Practice and Meaning from
Antiquity to Abstraction. (London:Thames & Hudson,
- Peacock, Kenneth. "Instruments to Perform Color-Music: Two
Centuries of Technological Experimentation," Leonardo 21,
No. 4 (1988) 397-406.
- Jewanski, J. & N. Sidler (Eds.). Farbe - Licht - Musik.
Synaesthesie und Farblichtmusik. Bern: Peter Lang, 2006.
- Mahling, F. (1926) Das Problem der `audition colorée': Eine
historisch-kritische Untersuchung. Archiv für die gesamte
Psychologie, 57, 165-301.
- Fechner, Th. (1871) Vorschule der Aesthetik. Leipzig:
Breitkopf und Hartel.
- Campen, Cretien van (1996). De verwarring der zintuigen.
Artistieke en psychologische experimenten met synesthesie.
Psychologie & Maatschappij, vol. 20, nr. 1, pp.
- Campen, Cretien van (2009) Visual Music and Musical Paintings.
The Quest for Synesthesia in the Arts. In: F. Bacci & D.
Melcher. Making Sense of Art, making Art of Sense. Oxford: Oxford
- Steen, C. (2001). Visions Shared: A Firsthand Look into
Synesthesia and Art, Leonardo, Vol. 34, No. 3, Pages 203-208
- Marcia Smilack Website Accessed 20 Aug
- E-text of Mary Shelley's Frankenstein, see p.
- see Cytowic, Richard E. 2002. Synesthesia: a Union of the
Senses. Second edition. Cambridge, Massachusetts: MIT Press,
and Cytowic, R.E. & Eagleman, D.M. (2009) Wednesday is
Indigo Blue." Cambridge: MIT Press
- Nabokov, Vladimir. 1966. Speak, Memory: An Autobiography
Revisited. New York: Putnam.
- Ellington, as quoted in George, Don. 1981. Sweet
man: The real Duke Ellington. New York: G.P. Putnam’s Sons.
- Quoted from an anonymous article in the Neuen Berliner
Musikzeitung (29 August, 1895); quoted in Mahling,
Friedrich. 1926. "Das Problem der 'Audition colorée: Eine
historische-kritische Untersuchung." Archiv für die Gesamte
Psychologie; LVII Band. Leipzig: Akademische
Verlagsgesellschaft M.B.H. Pp. 165-301. Page 230. Translation by
Sean A. Day.
- according to the Russian press: Yastrebtsev V. "On
N.A.Rimsky-Korsakov's color sound- contemplation." Russkaya
muzykalnaya gazeta, 1908, N 39-40, p. 842-845 (in Russian),
cited by Bulat Galeyev (1999).
- see Samuel, Claude. 1994 (1986). Olivier Messiaen: Music
and Color. Conversations with Claude Samuel. Translated by E.
Thomas Glasow. Portland, Oregon: Amadeus Press.
- Feynman, Richard. 1988. What Do You Care What Other People
Think? New York: Norton. P. 59.
- It just always stuck out in my mind, and I could always see it.
I don't know if that makes sense, but I could always visualize what
I was hearing... Yeah, it was always like weird colors." From a
Nightline interview with Pharrell
- Baron-Cohen, S. and Harrison,
J. (Eds., 1997). Synaesthesia: Classic and Contemporary
Readings. Oxford: Blackwell Publishers. ISBN
- Bosch, P. (2007) The Name of This Book is
Secret Little, Brown Young Readers. ISBN
- Campen, Cretien van. (2007)
The Hidden Sense. Synesthesia in Art and Science.
Cambridge, MA: MIT Press/Leonardo Books. ISBN 0-262-22081-4
- Cytowic, R.E. (2003)The Man
Who Tasted Shapes. Cambridge: MIT Press ISBN
- Cytowic, R.E. (2002)
Synesthesia: A Union of The Senses, second edition.
Cambridge: MIT Press ISBN 978-0-26-2032964.
- Cytowic, R.E. & Eagleman, D.M. (2009) Wednesday is Indigo
Blue: Discovering the Brain of Synesthesia, with an afterword
by Dmitri Nabokov. Cambridge: MIT
Press ISBN 978-0-26-201279-9.
- Dann, K. (1998). Bright Colors Falsely Seen.
Cambridge: Harvard University Press. ISBN 0-300-06619-8.
- Duffy, P. L. (2001). Blue Cats and Chartreuse
Kittens: How Synesthetes Color their Worlds. New York: Henry
Holt & Company. ISBN 0-7167-4088-5.
- Harrison, J. (2001). Synaesthesia: The Strangest
Thing. Oxford: Oxford University Press. ISBN
- Jay, C. (2009) Breathing in Colour. Little, Brown.
- Robertson, L. and Sagiv, N. (Eds., 2005). Synesthesia:
Perspectives from Cognitive Neuroscience. Oxford: Oxford
University Press. ISBN 0-19-516623-X.
- Tammet, D. (2006) Born on a
Blue Day: A Memoir of Aspergers and an Extraordinary Mind.
Hodder & Stoughton Ltd. ISBN 978-0-34-089974-8.
- Mass, W. (2003) A Mango-Shaped
Space. Little, Brown and Company. ISBN 0-316-52388-7
- Ward, J. (2008) The Frog who croaked Blue: Synesthesia and
the Mixing of the Senses. Routledge. ISBN
On the Web
- TED Blog, including video links to V. S. Ramachandran's TED talk.
- Cytowic's video lecture at the Smithsonian's Hirshhorn
Museum Visual Music exhibit. Four-part YouTube version
- Scientific American
article Hearing Colors, Tasting Shapes ( PDF
version) by Ramachandran & Hubbard, May 2003.
- Campen, Cretien van (2009),
The Hidden Sense: On Becoming Aware of
Synesthesia, TECCOGS , vol. 1, pp. 1–13.
- Video: David Eagleman talk: Hearing colours, tasting
sounds June 2009, SlowTV