2. 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)
3. Welcome to my world
of synesthesia!
Welcome to my world
of synesthesia!
5. 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
7. DATA: FIGURE 1 (ENGLISH
DICTIONARY)
Synesthetic Associational Pattern between R2=
R² = 0.659
1000 Frequencies 0.6597
Color wavelength (nm)
300
0.1 1 10 100
Frequency in the English Language (%)
9. DATA: FIGURES 3 AND 4
(SPANISH/GERMAN)
Synesthetic Associational Pattern
Between Frequencies in the Spanish r² = 0.47
Language
700
Color wavelength (nm)
600
500
400
300
200
100
0
0.01 0.1 1 10
Frequency in the Spanish Language (%) Synesthetic Associational Pattern
Between Frequencies in the German
Language
700
Color wavelength (nm)
600
500
400
300
200
100
0
r² = 0.72
0.01 0.1 1 10
Frequency in the German Language (%)
10. DATA: FIGURE 5 (CHILDREN’S
BOOKS)
Synesthetic Associational Pattern Between
Frequencies in Children's Books R² =
R² = 0.565
1000 0.5656
Color Wavelength (nm)
100
0 2 4 6 8 10 12 14
Letter Frequency (%)
11.
12. 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
13. V4 and the LMTG. They are closely situated, as
supports the theory of their connectivity in
synesthetes.
14. 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.
15. BIBLIOGRAPHY
Barnett, K. J., Finucane, C., Asher, J.E., Bargary, G., Corvin, A.
P., Newell, F.N., Mitchell, K.J. (2007). Familial patterns and the origins of individual
differences in synaesthesia. Cognition, 106, 871-893.
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.
Nunn, J.A., Gregory, L.J., Brammer, M., Williams, S.C.R., Parslow, D.M., Morgan, M.J., Mor
ris, R.G., Bullmore, E.T., Baron-Cohen, S., Gray, J.A. (2002) Functional magnetic
resonance imaging of synesthesia: activation of V4/V8 by spoken words. Natural
Neuroscience, 4, 371-5.
Rich, A.N., Bradshaw, J.L., Mattingley, J.B. (2004). A systematic, large-scale study of
synaesthesia: implications for the role of early experience in lexical-colour associations.
Cognition. 98, 53–84.
Rissman, J. (2003). An Event-Related fMRI Investigation of Implicit Semantic Priming.
Journal of Cognitive Neuroscience, 8, 1160-75.
the r-squared values commonly found in psychology (.09 to .25). Explain that although these r-square's indicate that we fail to account for a great deal of the variability in human behavior, that's to be expected because (1) we have measurement error, and (2) we wouldn't expect a single variable (e.g., IQ) to account for all the variance in another variable (college performance).
Neurophysiologically, this pattern can be described by the wavelength-specific color receptor neurons of V4 being fused with the language processing neurons of the left middle temporal gyrus that are prone to perform semantic recognition. The characteristics of these two areas, such as frequency selectivity of V4, match the characteristics of synesthesia first discovered in this research: more frequent letters (interpreted in the LMTG) correspond with colors of longer wavelength (as are preferable in V4), corresponding with the letter frequencies of the native language of the synesthete.
Priming, greek/hebrew case study, mturk, biological methylation epigenetics
