SYNESTHETIC ASSOCIATIONAL PATTERNS BETWEEN LETTERS AND COLORSLaura Mariah Herman |Vision Sciences Lab, Department of Psychology, Harvard University, Cambridge, MA 02138, USA

Pine Crest School, Fort Lauderdale, FL

BACKGROUND

• Synesthesia: inherent blending of the senses.– Grapheme-color is most common:

letters/numbers→colors

– Each synesthete associates each letter with different colors

– Caused by excess neuronal connections per mutated enzyme

– Single nucleotide polymorphism (16th chromosome)

• Genetically transmitted to ~0.01% of population

Welcome to my world of synesthesia!

Welcome to my world of synesthesia!

QUESTION

What causes certain letters to be associated with

certain colors? Why is this A red?

MATERIALS & METHODS

• Color frequency (wavelengths) compared to letter frequency (%)

• Synesthete color charts collective of synesthetes of the language (color the majority of synesthetes associated with each letter was used)

• English: dictionary vs. Brown Corpus (better cross-section of English language) vs. children’s books (synesthetic associations form as the subject learns the alphabet and remain the same)

• English, Spanish, German to verify causation vs. coincidence

SYNESTHETE COLOR CHARTS

0 0 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 0 0 00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 1 0 0 0 0 1 1 0 0 0 1 0 0 0 0 0 0 0 00 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 00 0 1 0 0 0 1 1 0 0 0 1 0 1 0 0 0 0 0 0 1 0 1 0 0 00 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 2 0 0 00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 3 2 2 0 0 0 2 0 0 0 1 0 1 0 0 1 0 0 1 0 1 0 05 0 3 0 1 0 0 0 2 3 1 1 2 3 1 0 1 0 4 0 0 2 1 1 2 00 0 0 0 0 0 3 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 00 0 1 0 1 3 0 1 0 0 2 0 0 0 0 1 1 0 0 0 0 1 1 2 1 10 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 10 0 0 0 0 0 0 1 0 1 1 2 1 1 0 0 2 0 0 0 0 0 1 1 1 10 0 0 1 0 1 0 0 3 0 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 2 0 0 0 0 11 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 00 0 0 2 1 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 1 0 0 0 0 00 1 0 0 3 0 0 0 0 0 0 0 3 0 0 2 0 0 1 0 0 0 0 0 0 05 2 1 0 1 0 1 1 0 0 1 0 2 2 0 3 0 0 1 0 1 0 0 0 0 10 0 1 0 0 0 1 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 1 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 01 2 1 1 0 1 1 0 0 1 1 3 0 0 0 0 1 0 0 4 1 0 0 0 2 30 0 0 0 0 1 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 3 0 0 1 0 1 1 0 0 0 0 0 0 0 3 1 0 0 0 0 0 1 10 3 0 0 0 0 1 0 0 1 1 0 1 0 2 3 0 3 0 0 0 2 1 0 0 20 3 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 1 0 1 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 00 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 1 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 2 1 0 0 0 0 00 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 1 0 0 0 0 0 00 0 0 0 0 0 0 1 0 0 0 0 0 2 3 0 2 0 0 1 0 0 1 3 1 312 12 12 11 10 11 11 11 7 10 8 9 12 13 9 10 10 7 11 9 9 11 11 10 8 14

English

Spanish

German

DATA: FIGURE 1 (ENGLISH DICTIONARY)

0.1 1 10 100300

R² = 0.659709581415141

Synesthetic Associational Pattern between Frequencies

Frequency in the English Language (%)

Colo

r w

avele

ngth

(nm

)

1000

R2= 0.6597

DATA: FIGURE 2 (BROWN CORPUS)

R2= 0.45299

DATA: FIGURES 3 AND 4 (SPANISH/GERMAN)

0.01 0.1 1 10 1000

100200300400500600700

Synesthetic Associational Pattern Between Frequencies

in the Spanish Language

Frequency in the Spanish Language (%)

Colo

r w

avele

ngth

(nm

)

0.01 0.1 1 10 1000

100

200

300

400

500

600

700

Synesthetic Associational Pattern Between Frequencies in the

German Language

Frequency in the German Language (%)

Colo

r w

avele

ngth

(nm

)

r² = 0.47

 

r² = 0.72

 

DATA: FIGURE 5 (CHILDREN’S BOOKS)

0 2 4 6 8 10 12 14100

1000

R² = 0.565583750087507

Synesthetic Associational Pattern Between Frequencies in Children's Books

Letter Frequency (%)

Colo

r W

avele

ngth

(nm

)

R² = 0.5656

DATA: FIGURE 6 (SATURATION)

0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.10

2

4

6

8

10

12

14

R² = 0.158740010717967

Synesthetic Associational Pattern Be-tween Letter Frequency and Saturation

(B)

Lett

er

Frequency

(%

)

Saturation Value

NEUROPHYSIOLOGICAL THEORY• From data, theorized which “color” and “letter”

areas of the brain are fused in synesthetes

• V4- color center in occipital lobe

– Previously suggested by fMRIs of synesthetes

– Columnar structure of neurons organized by long, middle, short wavelength cone signals as matches previous data

– Neuron preference for more saturated colors as well as long-wavelength colors

• Left Middle Temporal Gyrus (LMTG)- semantic processing/sensory integration

– Lends itself to functional neuroconnections

– Core component of individuality of semantic system

• fusion of V4 and LMTG supported functionally and topographically

V4 and the LMTG. They are closely situated, as supports the theory of their

connectivity in synesthetes.

DISCUSSION AND APPLICATIONS

• First synesthetic color/letter association pattern found• Mapping of not only synesthetic connections, but also

V4/LMTG (perhaps the largely uncharted LMTG is organized according to frequency of letters, etc.)

• Induce (visual memory, artistic talent)/reduce (overwhelming colors for some synesthetes) synesthesia

• Autism, schizophrenia, and epilepsy also caused by excess neuronal connections- synesthetes provide a model brain not inhibited by medication or cognitive impairments.– For example, sensory areas of the brain connected with the

limbic system (anger management) in autistics, causing simple sensory cues to extremely anger the patient

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Beeli, G., Esslen, M., Jancke, L. (2007). Frequency Correlates in Grapheme-Color Synesthesia. Psychological Science, 18-9: 788-792.

Berlin, B., & Kay, P. (1969). Basic color terms: Their universality and evolution. Berkeley: University of California Press.

Emrich, H., Schneider, U., Zedler, M. Welche Farbe hat der Montag? Berlin: S. Herzel Verlag, 2004.

Kotake, Y. (2009). Organization of Color-Selective Neurons in Macaque Visual Area V4. Journal of Neurophysiology, 102, 15-27.

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Rissman, J. (2003). An Event-Related fMRI Investigation of Implicit Semantic Priming. Journal of Cognitive Neuroscience, 8, 1160-75.

Scullion, Val., Treby, Marrion.,(2010). Creative Synaesthesia in E. T. A. Hoffmann’s Ritter Gluck. European Review. 18: 239-262.

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Roland, D., Dick, F., & Elman, J. L. (2007). Frequency of basic English grammatical structures: A corpus analysis. Journal of Memory and Language, 57(3), 348-379.

THANK YOU FOR YOUR TIME AND CONSIDERATION!