The merit of synesthesia for consciousness research

Frontiers in Psychology

Volumn 6, Issue DEC, 2015, Pages

  van Leeuwen, Tessa M ^a,b,c   Singer, Wolf ^a,b,d   Nikolić, Danko ^a,b,d,e  

^a MAX PLANCK INSTITUTE FOR BRAIN RESEARCH   (Germany)

^b ERNST STRÜNGMANN INSTITUTE ESI FOR NEUROSCIENCE IN COOPERATION WITH MAX PLANCK SOCIETY   (Germany)

^c RADBOUD UNIVERSITY NIJMEGEN   (Netherlands)

^d FRANKFURT INSTITUTE FOR ADVANCED STUDIES   (Germany)

^e UNIVERSITY OF ZAGREB   (Croatia)

Author keywords

Ambiguous stimuli; Consciousness; Effective connectivity; NCC; Parietal cortex; Qualia; Semantics; Synesthesia

Indexed keywords

EID: 84954223140     PISSN: None     EISSN: 16641078     Source Type: Journal    
DOI: 10.3389/fpsyg.2015.01850     Document Type: Review

References (100)

1. Aru, J., Bachmann, T., Singer, W., and Melloni, L. (2012). Distilling the neural correlates of consciousness. Neurosci. Biobehav. Rev. 36, 737-746. doi: 10.1016/j.neubiorev.2011.12.003
2. Banissy, M. J., Holle, H., Cassell, J., Annett, L., Tsakanikos, E., Walsh, V., et al. (2013). Personality traits in people with synaesthesia: do synaesthetes have an atypical personality profile? Pers. Individ. Dif. 54, 828-831. doi: 10.1016/j.paid.2012.12.018
3. Banissy, M. J., Stewart, L., Muggleton, N. G., Griffiths, T. D., Walsh, V. Y., Ward, J., et al. (2012). Grapheme-color and tone-color synesthesia is associated with structural brain changes in visual regions implicated in color, form, and motion. Cogn. Neurosci. 3, 29-35. doi: 10.1080/17588928.2011.594499
4. Bargary, G., and Mitchell, K. J. (2008). Synaesthesia and cortical connectivity. Trends Neurosci. 31, 335-342. doi: 10.1016/j.tins.2008.03.007
5. Barnett, K. J., Foxe, J. J., Molholm, S., Kelly, S. P., Shalgi, S., Mitchell, K. J., et al. (2008). Differences in early sensory-perceptual processing in synesthesia: a visual evoked potential study. Neuroimage. 43, 605-613. doi: 10.1016/j.neuroimage.2008.07.028
6. Baron-Cohen, S., Wyke, M. A., and Binnie, C. (1987). Hearing words and seeing colours: an experimental investigation of a case of synaesthesia. Perception 16, 761-767. doi: 10.1068/p160761
7. Beeli, G., Esslen, M., and Jäncke, L. (2008). Time course of neural activity correlated with colored-hearing synesthesia. Cereb. Cortex 18, 379-385. doi: 10.1093/cercor/bhm072
8. Brang, D., Hubbard, E. M., Coulson, S., Huang, M., and Ramachandran, V. S. (2010). Magnetoencephalography reveals early activation of V4 in grapheme-color synesthesia. Neuroimage 53, 268-274. doi: 10.1016/j.neuroimage.2010.06.008
9. Brang, D., Rouw, R., Ramachandran, V. S., and Coulson, S. (2011). Similarly shaped letters evoke similar colors in grapheme-color synesthesia. Neuropsychologia 49, 1355-1358. doi: 10.1016/j.neuropsychologia.2011.01.002
10. Chalmers, D. J. (1995). Facing up to the problem of consciousness. J. Conscious. Stud. 2, 200-219.
11. Chan, J. S., Van Den Bosch, J. J. F., Theves, S., Hardt, S., Pflanz, P., Lötsch, J., et al. (2014). Synaesthesia or vivid imagery? A single case fMRI study of visually induced olfactory perception. Multisens. Res. 27, 225-246. doi: 10.1163/22134808-00002451
12. Chiou, R., and Rich, A. N. (2014). The role of conceptual knowledge in understanding synaesthesia: evaluating contemporary findings from a "hub-and-spokes" perspective. Front. Psychol. 5:105. doi: 10.3389/fpsyg.2014.00105
13. Cohen, M. A., and Dennett, D. C. (2011). Consciousness cannot be separated from function. Trends Cogn. Sci. 15, 358-364. doi: 10.1016/j.tics.2011.06.008
14. Crick, F. H. C. (1994). The Astonishing Hypothesis: The Scientific Search for the Soul. New York, NY: Scribner.
15. Cytowic, R. E. (1993). The Man Who Tasted Shapes. Cambridge: MIT Press.
16. Day, S. A. (2014). Types of Synesthesia. Retrieved from: http://www.daysyn.com/Types-of-Syn.html
17. Dehaene, S., and Naccache, L. (2001). Towards a cognitive neuroscience of consciousness: basic evidence and a workspace framework. Cognition 79, 1-37. doi: 10.1016/S0010-0277(00)00123-2
18. Dixon, M. J., Smilek, D., Cudahy, C., and Merikle, P. M. (2000). Two plus five equals yellow. Nature 406, 365. doi: 10.1038/35019148
19. Dixon, M. J., Smilek, D., Duffy, P. L., Zanna, M. P., and Merikle, P. M. (2006). The role of meaning in grapheme-colour synaesthesia. Cortex 42, 243-252. doi: 10.1016/S0010-9452(08)70349-6
20. Dixon, M. J., Smilek, D., and Merikle, P. M. (2004). Not all synaesthetes are created equal: projector versus associator synaesthetes. Cogn. Affect. Behav. Neurosci. 4, 335-343. doi: 10.3758/CABN.4.3.335
21. Dovern, A., Fink, G. R., Fromme, A. C. B., Wohlschläger, A. M., Weiss, P. H., and Riedl, V. (2012). Intrinsic network connectivity reflects consistency of synesthetic experiences. J. Neurosci. 32, 7614-7621. doi: 10.1523/JNEUROSCI.5401-11.2012
22. Eagleman, D. M., and Goodale, M. A. (2009). Why color synesthesia involves more than color. Trends Cogn. Sci. 13, 288-292. doi: 10.1016/j.tics.2009.03.009
23. Eagleman, D. M., Kagan, A. D., Nelson, S. S., Sagaram, D., and Sarma, A. K. (2007). A standardized test battery for the study of synesthesia. J. Neurosci. Methods 159, 139-145. doi: 10.1016/j.jneumeth.2006.07.012
24. Edquist, J., Rich, A. N., Brinkman, C., and Mattingley, J. B. (2006). Do synaesthetic colours act as unique features in visual search? Cortex 42, 222-231. doi: 10.1016/S0010-9452(08)70347-2
25. Gallace, A., and Spence, C. (2006). Multisensory synesthetic interactions in the speeded classification of visual size. Percept. Psychophys. 68, 1191-1203. doi: 10.3758/BF03193720
26. Gheri, C., Chopping, S., and Morgan, M. J. (2008). Synaesthetic colours do not camouflage form in visual search. Proc. R. Soc. B Biol. Sci. 275, 841-846. doi: 10.1098/rspb.2007.1457
27. Goller, A. I., Otten, L. J., and Ward, J. (2009). Seeing sounds and hearing colors: an event-related potential study of auditory-visual synesthesia. J. Cogn. Neurosci. 21, 1869-1881. doi: 10.1162/jocn.2009.21134
28. Gray, J. (2005). "Synesthesia: a window on the hard problem of consciousness, "in Synesthesia: Perspectives From Cognitive Neuroscience, eds L. C. Robertson and N. Sagiv (New York, NY: Oxford University Press), 127-146.
29. Grossenbacher, P. G., and Lovelace, C. T. (2001). Mechanisms of synesthesia: cognitive and physiological constraints. Trends Cogn. Sci. 5, 36-41. doi: 10.1016/S1364-6613(00)01571-0
30. Hänggi, J., Beeli, G., Oechslin, M. S., and Jäncke, L. (2008). The multiple synaesthete ES - Neuroanatomical basis of interval-taste and tone-colour synaesthesia. Neuroimage 43, 192-203. doi: 10.1016/j.neuroimage.2008.07.018
31. Hänggi, J., Wotruba, D., and Jäncke, L. (2011). Globally altered structural brain network topology in grapheme-color synesthesia. J. Neurosci. 31, 5816-5828. doi: 10.1523/JNEUROSCI.0964-10.2011
32. Harnad, S. (1995). Why and how we are not zombies. Philos. Explor. 1, 164-167.
33. Hochel, M., and Milán, E. G. (2008). Synaesthesia: the existing state of affairs. Cogn. Neuropsychol. 25, 93-117. doi: 10.1080/02643290701822815
34. Hubbard, E. M., Brang, D., and Ramachandran, V. S. (2011). The cross-activation theory at 10. J. Neuropsych. 5, 152-177. doi: 10.1111/j.1748-6653.2011.02014.x
35. Hupé, J.-M., Bordier, C., and Dojat, M. (2012). The neural bases of grapheme-color synesthesia are not localized in real color-sensitive areas. Cereb. Cortex 22, 1622-1633. doi: 10.1093/cercor/bhr236
36. Jäncke, L., Beeli, G., Eulig, C., and Hanggi, J. (2009). The neuroanatomy of grapheme-color synesthesia. Eur. J. Neurosci. 29, 1287-1293. doi: 10.1111/j.1460-9568.2009.06673.x
37. Jewanski, J., Day, S. A., and Ward, J. (2009). A colorful albino: the first documented case of synaesthesia, by Georg Tobias Ludwig Sachs in 1812. J. Hist. Neurosci. 18, 293-303. doi: 10.1080/09647040802431946
38. Jürgens, U. M., and Nikolic, D. (2012). Ideaesthesia: conceptual processes assign similar colours to similar shapes. Translat. Neurosci. 3, 22-27. doi: 10.2478/s13380-012-0010-4
39. Köhler, W. (1947). Gestalt Psychology: An Introduction to New Concepts in Modern Psychology. New York, NY: Liveright.
40. Laeng, B. (2009). Searching through synaesthetic colors. Atten. Percept. Psychophys. 71, 1461-1467. doi: 10.3758/APP.71.7.1461
41. Lamme, V. A. (2006). Towards a true neural stance on consciousness. Trends Cogn. Sci. 10, 494-501. doi: 10.1016/j.tics.2006.09.001
42. Majid, A., Bowerman, M., Kita, S., Haun, D. B. M., and Levinson, S. C. (2004). Can language restructure cognition? The case for space. Trends Cogn. Sci. 8, 108-114. doi: 10.1016/j.tics.2004.01.003
43. Mattingley, J. B. (2009). Attention, automaticity, and awareness in synesthesia. Ann. N.Y. Acad. Sci. 1156, 141-167. doi: 10.1111/j.1749-6632.2009.04422.x
44. McClelland, J. L., and Rumelhart, D. E. (1985). Distributed memory and the representation of general and specific information. J. Exp. Psychol. Gen. 114, 159-188. doi: 10.1037/0096-3445.114.2.159
45. Melloni, L., Molina, C., Pena, M., Torres, D., Singer, W., and Rodriguez, E. (2007). Synchronization of neural activity across cortical areas correlates with conscious perception. J. Neurosci. 27, 2858-2865. doi: 10.1523/JNEUROSCI.4623-06.2007
46. Metzinger, T. (2000). Neural Correlates of Consciousness: Empirical and Conceptual Questions. Cambridge, MA: MIT Press.
47. Milán, E., Iborra, O., De Cordoba, M. J., Juarez-Ramos, V., Artacho, M. A. R., and Rubio, J. L. (2013). The Kiki-Bouba effect A case of personification and ideaesthesia. J. Conscious. Stud. 20, 84-102. Available online at: http://www.ingentaconnect.com/content/imp/jcs/2013/00000020/F0020001/art00005
48. Mills, C. B., Viguers, M. L., Edelson, S. K., Thomas, A. T., Simon-Dack, S. L., and Innis, J. A. (2002). The color of two alphabets for a multilingual synesthete. Perception 31, 1371-1394. doi: 10.1068/p3429
49. Mroczko, A., Metzinger, T., Singer, W., and Nikolic, D. (2009). Immediate transfer of synesthesia to a novel inducer. J. Vis. 9, 8. doi: 10.1167/9.12.25
50. Mroczko-Wasowicz, A., and Nikolic, D. (2014). Semantic mechanisms may be responsible for developing synesthesia. Front. Hum. Neurosci. 8:509. doi: 10.3389/fnhum.2014.00509
51. Myles, K. M., Dixon, M. J., Smilek, D., and Merikle, P. M. (2003). Seeing double: the role of meaning in alphanumeric colour synaesthesia. Brain Cogn. 53, 342-345. doi: 10.1016/S0278-2626(03)00139-8
52. Neufeld, J., Sinke, C., Dillo, W., Emrich, H. M., Szycik, G. R., Dima, D., et al. (2012a). The neural correlates of coloured music: a functional MRI investigation of auditory-visual synaesthesia. Neuropsychologia 50, 85-89. doi: 10.1016/j.neuropsychologia.2011.11.001
53. Neufeld, J., Sinke, C., Zedler, M., Dillo, W., Emrich, H. M., Bleich, S., et al. (2012b). Disinhibited feedback as a cause of synesthesia: evidence from a functional connectivity study on auditory-visual synesthetes. Neuropsychologia 50, 1471-1477. doi: 10.1016/j.neuropsychologia.2012.02.032
54. Newell, F. N., and Mitchell, K. (2015). Multisensory integration and cross-modal learning in synaesthesia: a unifying model. Neuropsychologia. doi: 10.1016/j.neuropsychologia.2015.07.026. [Epub ahead of print].
55. Nikolic, D. (2009). "Is synaesthesia actually ideaestesia? An inquiry into the nature of the phenomenon, "in Proceedings of the Third International Congress on Synaesthesia, Science and Art (Granada), 26-29.
56. Nikolic, D. (2015). Practopoiesis: or how life fosters a mind. J. Theor. Biol. 373, 40-61. doi: 10.1016/j.jtbi.2015.03.003
57. Nikolic, D., Jürgens, U. M., Rothen, N., Meier, B., and Mroczko, A. (2011). Swimming-style synesthesia. Cortex 47, 874-879. doi: 10.1016/j.cortex.2011.02.008
58. Novich, S., Cheng, S., and Eagleman, D. M. (2011). Is synaesthesia one condition or many? A large-scale analysis reveals subgroups. J. Neuropsychol. 5, 353-371. doi: 10.1111/j.1748-6653.2011.02015.x
59. O'Hanlon, E., Newell, F. N., and Mitchell, K. J. (2013). Combined structural and functional imaging reveals cortical deactivations in grapheme-color synaesthesia. Fron. Psychol. 4:755. doi: 10.3389/fpsyg.2013.00755
60. Palmeri, T. J., Blake, R., Marois, R., Flanery, M. A., and Whetsell, W. J. (2002). The perceptual reality of synesthetic colors. Proc. Natl. Acad. Sci. U.S.A. 99, 4127-4131. doi: 10.1073/pnas.022049399
61. Price, M. C., and Mattingley, J. B. (2013). Automaticity in sequence-space synaesthesia: a critical appraisal of the evidence. Cortex 49, 1165-1186. doi: 10.1016/j.cortex.2012.10.013
62. Ramachandran, V. S., and Hubbard, E. M. (2001). Psychophysical investigations into the neural basis of synaesthesia. Proc. R. Soc. B Biol. Sci. 268, 979-983. doi: 10.1098/rspb.2000.1576
63. Rothen, N., and Meier, B. (2009). Do synesthetes have a general advantage in visual search and episodic memory? A case for group studies. PLoS ONE 4:e5037. doi: 10.1371/journal.pone.0005037
64. Rouw, R., and Scholte, H. S. (2007). Increased structural connectivity in grapheme-color synesthesia. Nat. Neurosci. 10, 792-797. doi: 10.1038/nn1906
65. Rouw, R., and Scholte, H. S. (2010). Neural basis of individual differences in synesthetic experiences. J. Neurosci. 30, 6205-6213. doi: 10.1523/JNEUROSCI.3444-09.2010
66. Rouw, R., Scholte, H. S., and Colizoli, O. (2011). Brain areas involved in synaesthesia: a review. J. Neuropsychol. 5, 214-242. doi: 10.1111/j.1748-6653.2011.02006.x
67. Rubinsten, O., and Henik, A. (2002). Is an ant larger than a lion? Acta Psychol. 111, 141-154. doi: 10.1016/S0001-6918(02)00047-1
68. Sagiv, N., and Frith, C. D. (2013). "Synesthesia and consciousness, "in Oxford Handbook of Synesthesia, eds J. Simner and E. M. Hubbard (Oxford; New York, NY: Oxford University Press), 924-940.
69. Sagiv, N., Heer, J., and Robertson, L. (2006). Does binding of synesthetic color to the evoking grapheme require attention? Cortex 42, 232-242. doi: 10.1016/S0010-9452(08)70348-4
70. Simner, J. (2012). Defining synaesthesia. Br. J. Psychol. 103, 1-15. doi: 10.1348/000712610X528305
71. Simner, J., and Bain, A. E. (2013). A longitudinal study of grapheme-colour synaesthesia in childhood: 6/7 years to 10/11 years. Front. Hum. Neurosci. 7:603. doi: 10.3389/fnhum.2013.00603
72. Simner, J., Mulvenna, C., Sagiv, N., Tsakanikos, E., Witherby, S. A., Fraser, C., et al. (2006). Synaesthesia: the prevalence of atypical cross-modal experiences. Perception 35, 1024-1033. doi: 10.1068/p5469
73. Simner, J., Ward, J., Lanz, M., Jansari, A., Noonan, K., Glover, L., et al. (2005). Non-random associations of graphemes to colours in synaesthetic and non-synaesthetic populations. Cogn. Neuropsychol. 22, 1069-1085. doi: 10.1080/02643290500200122
74. Singer, W. (2001). Consciousness and the binding problem. Ann. N.Y. Acad. Sci. 929, 123-146. doi: 10.1111/j.1749-6632.2001.tb05712.x
75. Singer, W. (2015). "Large scale temporal coordination of cortical activity as prerequisite for conscious experience, "in The Blackwell Companion to Consciousness, eds M. Velmans and S. Schneider (Oxford, UK: Blackwell Publishing). doi: 10.1002/9780470751466.ch48
76. Sinke, C., Neufeld, J., Emrich, H. M., Dillo, W., Bleich, S., Zedler, M., et al. (2012). Inside a synesthete's head: a functional connectivity analysis with grapheme-color synesthetes. Neuropsychologia 50, 3363-3369. doi: 10.1016/j.neuropsychologia.2012.09.015
77. Smilek, D., Dixon, M. J., Cudahy, C., and Merikle, P. M. (2001). Synaesthetic photisms influence visual perception. J. Cogn. Neurosci. 13, 930-936. doi: 10.1162/089892901753165845
78. Spence, C. (2011). Crossmodal correspondences: a tutorial review. Atten. Percept. Psychophys. 73, 971-995. doi: 10.3758/s13414-010-0073-7
79. Sperling, J. M., Prvulovic, D., Linden, D. E. J., Singer, W., and Stirn, A. (2006). Neuronal correlates of colour-graphemic synaesthesia: a fMRI study. Cortex 42, 295-303. doi: 10.1016/S0010-9452(08)70355-1
80. Stroop, J. R. (1935). Studies of interference in serial verbal reactions. J. Exp. Psychol. 18, 643-662. doi: 10.1037/h0054651
81. Tang, J., Ward, J., and Butterworth, B. (2008). Number forms in the brain. J. Cogn. Neurosci. 20, 1547-1556. doi: 10.1162/jocn.2008.20120
82. Tomson, S. N., Narayan, M., Allen, G. I., and Eagleman, D. M. (2013). Neural networks of colored sequence synesthesia. J. Neurosci. 33, 14098-14106. doi: 10.1523/JNEUROSCI.5131-12.2013
83. van Leeuwen, T. M. (2013). "Individual differences in synesthesia, "in Oxford Handbook of Synesthesia, eds J. Simner and E. M. Hubbard (Oxford; New York, NY: Oxford University Press), 241-264. doi: 10.1093/oxfordhb/9780199603329.013.0013
84. Van Leeuwen, T. M. (2014). Constructing priors in synesthesia. Cogn. Neurosci. 5, 124-126. doi: 10.1080/17588928.2014.905520
85. Van Leeuwen, T. M., den Ouden, H. E. M., and Hagoort, P. (2011). Effective connectivity determines the nature of subjective experience in grapheme-color synesthesia. J. Neurosci. 31, 9879-9884. doi: 10.1523/JNEUROSCI.0569-11.2011
86. Van Leeuwen, T. M., Hagoort, P., and Handel, B. F. (2013). Real color captures attention and overrides spatial cues in grapheme-color synesthetes but not in controls. Neuropsychologia 51, 1802-1813. doi: 10.1016/j.neuropsychologia.2013.06.024
87. Van Leeuwen, T. M., Petersson, K. M., and Hagoort, P. (2010). Synaesthetic colour in the brain: beyond colour areas. A functional magnetic resonance imaging study of synaesthetes and matched controls. PLoS ONE 5:e12074. doi: 10.1371/journal.pone.0012074
88. Walker, L., Walker, P., and Francis, B. (2012). A common scheme for cross-sensory correspondences across stimulus domains. Perception 41, 1186. doi: 10.1068/p7149
89. Walker, P., and Walker, L. (2012). Size-brightness correspondence: crosstalk and congruity among dimensions of connotative meaning. Att. Percept. Psychophys. 74, 1226-1240. doi: 10.3758/s13414-012-0297-9
90. Ward, J., Huckstep, B., and Tsakanikos, E. (2006). Sound-colour synaesthesia: to what extent does it use cross-modal mechanisms common to us all? Cortex 42, 264-280. doi: 10.1016/s0010-9452(08)70352-6
91. Ward, J., Jonas, C., Dienes, Z., and Seth, A. (2010). Grapheme-colour synaesthesia improves detection of embedded shapes, but without pre-attentive 'pop-out' of synaesthetic colour. Proc. R. Soc. B Biol. Sci. 277, 1021-1026. doi: 10.1098/rspb.2009.1765
92. Ward, J., Li, R., Salih, S., and Sagiv, N. (2007). Varieties of grapheme-colour synaesthesia: a new theory of phenomenological and behavioural differences. Conscious. Cogn. 16, 913-931. doi: 10.1016/j.concog.2006.09.012
93. Ward, J., and Sagiv, N. (2007). Synaesthesia for finger counting and dice patterns: a case of higher synaesthesia? Neurocase 13, 86-93. doi: 10.1080/13554790701300518
94. Ward, J., Thompson-Lake, D., Ely, R., and Kaminski, F. (2008). Synaesthesia, creativity and art: what is the link? Br. J. Psychol. 99, 127-141. doi: 10.1348/000712607x204164
95. Weiss, P. H., and Fink, G. R. (2009). Grapheme-colour synaesthetes show increased grey matter volumes of parietal and fusiform cortex. Brain 132, 65-70. doi: 10.1093/brain/awn304
96. Witthoft, N., and Winawer, J. (2006). Synesthetic colors determined by having colored refrigerator magnets in childhood. Cortex 42, 175-183. doi: 10.1016/S0010-9452(08)70342-3
97. Witthoft, N., and Winawer, J. (2013). Learning, memory, and synesthesia. Psychol. Sci. 24, 258-265. doi: 10.1177/0956797612452573
98. Wollen, K. A., and Ruggiero, F. T. (1983). Colored-letter synesthesia. J. Ment. Imagery 7, 83-86.
99. Zamm, A., Schlaug, G., Eagleman, D. M., and Loui, P. (2013). Pathways to seeing music: enhanced structural connectivity in colored-music synesthesia. Neuroimage 74, 359-366. doi: 10.1016/j.neuroimage.2013.02.024
100. Zeki, S. (2001). Localization and globalization in conscious vision. Annu. Rev. Neurosci. 24, 57-86. doi: 10.1146/annurev.neuro.24.1.57