Synesthesia & Savant Syndrome
Synesthesia is a condition in which stimulation in one sensory or cognitive stream involuntarily, or automatically, leads to associated internal or external (illusory or hallucinatory) experiences in a second unstimulated sensory or cognitive system. Although most cases of synesthesia are developmental and run in families, acquired cases have also been reported following traumatic brain injury, demyelination, ischemia, tumors, post-traumatic total ocular blindness and neuropathology involving the optic nerve and/or chiasm.
Color synesthesia is a special kind of synesthesia that comprises cases of synesthesia in which a non-colored sensory or cognitive stimulus involuntarily leads to internal or external color experiences. The prevalence of color synesthesia is unknown. Estimates range from 1 in 200 to 1 in 250,000. Some speculate that color synesthesia may be present in more than 4 percent of the population.
One of the best-known forms of color synesthesia is grapheme-color synesthesia, in which numbers or letters are seen as colored. But lots of other forms of color synesthesia have been identified, including week-color synesthesia, sound-color synesthesia, taste-color synesthesia, fear-color synesthesia, etc.
One mark of color synesthesia is that the synesthetic colors are seen either as projected out onto the world (“projector synesthesia”) or in the mind's eye (“associator synesthesia”). Another mark is that it exhibits test-retest reliability: Colors identified by the subject as representative of her synesthetic experiences relative to a given stimulus in the initial testing phase are nearly identical to colors identified by the subject as representative of her synesthetic experiences relative to the same stimulus in a retesting phase at a later time.
Because of the automatic nature of synesthesia and its test-retest reliability, color synesthesia is not to be confused with memory associations or stereotypical colors of objects. For example, there is no evidence that color synesthetes simply remember the colors of entities or images they were exposed to earlier in their lives or associate stimuli with their stereotypical colors.
Synesthetic color experience is unique for each synesthete. For example, the letter A may trigger the color red in one grapheme-color synesthete but trigger the color blue in another. In fact, each grapheme has been found to trigger each of the 11 Berlin and Kay colors in different synesthetes (red, pink, orange, yellow, green, blue, purple, blown, black, white, gray). Despite the uniqueness of synesthetic color experience, synethetic colors sometimes fall into certain clusters. For example, grapheme-color synesthetes tend to associate A with red, E with yellow or white, I with black or white and O with white.
Savant Syndrome is an extremely rare condition in which an individual acquires extraordinary abilities in areas such as music performance and composition, drawing, or memory capacity. Many savants also have autism, but it is slightly misleading to characterize all savants as having autism as the popular name 'autistic savant' suggests. It is estimated that about 50% of the cases of savant syndrome are also autistic individuals. Savant syndrome can also occur after a traumatic brain injury or central nervous system (CNS) disease.
One example of a skill that a savant might possess is related to calendar recall. A savant who has this skill might be able to tell you which day of the week a particular date falls upon (or fell upon), up to thousands of years in either direction. These types of extraordinary skills typify savant syndrome, although they appear in a variety of different areas.
While there are many theories about savant syndrome, the cognitive mechanisms involved are poorly understood. Our research focuses on case studies of particular savants and their associated behaviors. In a forthcoming publication, The Superhuman Mind (by Berit Brogaard and Kristian Marlow), looks at these cases in detail and hopes to better understand this incredible phenomenon.
“Everything that exists has geometry,” says Jason Padgett, who acquired amazing mathematical abilities after a mugging incident in 2002. He was hit hard on the head, and he now experiences reality as mathematical fractals describable by equations. Light bouncing off a shiny car explodes into a fractal overlaying reality, the outer boundaries of objects are tangents, tiny pieces that change angles relative to one another and turn into picture frames of fractals during motion, and the boundaries of clouds and liquids are spiraling lines. Before the incident Jason was no whiz at math. He copied most of the answers on his geometry exam in high school and never had much interest in the subject matter. He went to college but never finished. He worked in sales for a few years and then moved onto a furniture store that sells furniture manufactured by his father.
The mugger’s stroke ostensibly changed the architecture of Jason's brain. After an introspective period lasting three years, he started drawing what he saw right in front of his eyes. The results were amazing, a series of hand-drawn approximations of mathematical fractals, the first of their kind. Mathematicians and physicists were taken aback: Some of Jason's drawings depict equations in math that hitherto were only presentable in graph form. Others depict actual electron interference patterns.
Savant syndrome is a condition in which a person has a talent that is so developed that he can perform what may seem like impossible mathematical, linguistic or artistic tasks. Savant skills tend to be right-brain or bilateral skills. Jason fits the standard characterization of savant syndrome. His savant skills fall into three groups: Artistic, mathematical and spatial. Jason had taken some college courses before the incident: accounting, micro- and macro-economics. But he never took a college math course. In fact, he never finished college. His last math course prior to the incident was a geometry course in high school where he copied most of the answers on the final exam. Prior to the attack Jason scored less than 100 on a standard IQ test and had no artistic abilities. He couldn’t even draw a decent picture in the popular game Pictionary.
Despite his lack of prior training, Jason is the only person in the world to have ever hand-drawn meticulously accurate approximations of mathematical fractals using only straight lines. He can predict the vectors for prime numbers in his drawings (see Fig. 1), and his drawing of hf = mc2, which contains all the style elements of his earliest drawings, is remarkably similar to an actual picture of electron interference patterns, which he found years after first drawing the pattern (see Figs. 2, 3). Like other individuals with savant syndrome and highly specialized artistic skills, Jason reached top scores on spatial ability tests, a standard component of many IQ tests, after the incident.
Atypical Responsiveness in Occipitotemporal Areas
Jason sees the boundaries of objects as sliced up into pieces or tangents and the boundaries of liquids and clouds as spiraling lines (Fig. 4). He never sees a smooth path. This condition resembles apperceptive agonosia in that his brain processes the boundaries of objects differently from most people. Jason's brain never creates a smooth line on the basis of the tangent lines he experiences. Upon further scrutiny, however, it is clear that this condition is not a form of visual agnosia. Jason's condition is not even remotely similar to apperceptive agnosia. He is clearly able to use Gestalt grouping principles to establish the frontier between object and background. Even though the boundaries of objects are fragmented, they stand out bright and solid from the background. The boundary he sees differs from the boundary we see but he can draw this boundary in ever so many details.
Imagine hearing what you see. This is reality for Lidell Simpson, a vision-to-sound synesthete. "Take this example of observing a single light being turned on then off. I will hear the 'plink' of the turning on, I will hear the 'whine' of the light and finally the 'plunk' of the light turning off." This description of his synesthesia is amazing considering that Lidell was born nearly deaf in both ears. This congenital defect made for a difficult childhood. For many years, doctors mistakenly told his parents that any hearing assistance could permanently damage the little hearing that Lidell could manifest at a later age. Because of the difficulty of communication with Lidell, doctors assumed he was mentally handicapped as well. Thanks to a caring family and despite the doctors' repeated insistence that Lidell be institutionalized, Lidell eventually was able to start hearing with the aid of an electronic device. It quickly became very clear that he was quite gifted intellectually. He became interested in computer programming and made his way to work for many of the top IT firms. Over the years Lidell has become acquainted with many respected researchers in neuroscience, philosophy, and psychology and regularly calls on his experiences to contribute to research. But what's most interesting about Lidell's case is that the synesthetic sounds he has had for his whole life are just as real as the ones coming through his ears. Says Lidell, "I have been deaf all my life, but silence I have never known."
For Lidell, visual scenery evokes many different layers of sound that correspond to different objects in the environment. Lidell thinks his synesthesia emerged from his lack of hearing as a child, "Imagine looking at water dripping from a faucet. You hear the dripping sound like I do. Now if you plug you ears, do you still hear it? If I turn off my hearing aids while looking at the falling droplets, I still hear the dripping sound! And the syn-sounds are just as loud as normal sounds even though the syn-sounds are internal. My memory of the sounds of dripping water is linked to visual imagery to compensate for my lack of auditory stimulation."
What's also interesting is that Lidell is subject to a very peculiar version of what scientists call the McGurk Effect. The McGurk Effect is a perceptual phenomenon that shows an interaction between hearing and vision in speech perception. The illusion occurs when the auditory component of one sound is paired with the visual component of another sound, leading to the perception of a third sound. For example, if in a video the syllable /ba-ba/ is audially dubbed over the lip movements of /ga-ga/, the viewer will perceive the sound to be of /da-da/. Lidell is subject to this effect when watching digital television because the separate audio and video channels arrive to the television at slightly different times. However minute the discrepancy might be, Lidell simply cannot understand television with the sound on. He can only hear what the speakers are saying if he turns the sound off and uses the closed captioning. Lidell tells us about a funny prank that his friend once played on him: he set the television to play Spanish over the secondary audio program. Because of Lidell's synesthesia, he didn't notice that he was listening to Spanish. But after suffering through Spanish for a week, the friend finally told Lidell of the prank. Lidell covered his eyes and immediately recognized he was listening to Spanish!
What's useful about it?
Lidell hears a unique "ping" that corresponds to every face he recognizes. This can be useful at times. If Lidell quickly scans a crowded room, he will hear a ping corresponding to the locations of people he has met before. He once was distracted by a ping coming from oncoming traffic on the freeway and turned around to find out that a family friend was dropping in without notice.
Megan has known she was a synesthete from a very young age. Her grandfather, a synesthete himself, once called and told her mother to ask what 3 was. Megan replied “blue.” A grapheme-color synesthete, Megan associates color and texture with every letter, number and word. Until her grandfather asked this question, she didn’t realize she saw the world differently from others. To her these colors were just a natural part of perception. Being different wasn’t always easy. Some friends unaware of synesthesia would treat her like she was crazy or looking for attention, so she started keeping it to herself. Now a nurse, Megan enthusiastically talks about synesthesia with anyone who will listen. And with the increasing awareness of synesthesia, many people now do. A member of the Facebook group “I’m not a freak, I’m a synesthete,” Megan is helping to demonstrate how many synesthetes are everyday people.
Megan is a “projector.” As opposed to associators who experience a strong relation between a percept and a color in the “mind’s eye,” projectors actually experience their colors or sensations out in space. For example, if Megan looks at the number 4 written in black ink, she will see another green 4 hovering above the actual letter. This can be annoying at times. Before Megan realized she was a synesthete, she once got very angry in school because letters on a set of blocks were the “wrong” color. When naming her son, it was very important that the colors in his name were well-coordinated. As is common in many grapheme-color synesthetes, each letter also has a particular texture and personality. For example, the number 0 is black and very shiny like asphalt, 1 is just white, 2 is a childish red, and 3 is a dark soft grandmotherly blue. Word search puzzles are particularly easy: The colors of target words several rows over grab her attention.
When Megan learned to play the piano, each key took on the color corresponding letter of the note. When she learned to play the flute, not only did the keys take on similar colors, but the shapes of her fingers playing each note did too. Uncommon among synesthetes, Megan also experiences music by touch. When she listens to music played on a piano, she feel the sounds literally “poking” her face. Strings vibrate in her chest. Waves from brass instruments pass in front of her, sometimes buzzing on her neck. Drums come up from below. Intensity increases with volume but these sensations are never unpleasant, as Megan feels like she is in the music.