My MSCA Individual Fellowship is focused on discovering the genetic underpinnings of synaesthesia, a neurological phenomenon where stimulation of one sense causes an automatic secondary perception. In this project, I study large families that have multiple generations of synaesthetes (grandma, mom, yourself, your cousin, etc.), and look for rare genetic differences that are specific to the people with synaesthesia.
Sound–Colour Synaesthesia
In this project, I started with three families that experience perceptions of colour when they hear sounds. We knew from a prior study by Simon Baron-Cohen’s lab at the University of Cambridge that these families were unlikely to share the same ‘synaesthesia mutation’ - their analysis pointed to a high degree of heterogeneity within even this single form of synaesthesia.
I used whole-exome sequencing to identify all of the potentially-protein changing genetic differences within these families. The paper describing how we identified a set of genes whose function connects the three families is currently in submission, and I’ll be speaking about the results at a synaesthesia conference in LA this October. You can also catch the results during my poster at the Society for Neuroscience meeting in Washington DC this November.
Grapheme–Colour Synaesthesia
Here, I am applying whole-genome sequencing sequencing to multiple families who experience letters and numbers as having colours (e.g. “A is a bright blue, and E is always yellow”). By studying a differnt form of synaesthesia, I can investigate whether they have anything in common at the genetic level. Many synaesthetes experience more than one form, making it likely that at least in some cases their genetics make them more succeptible to synaesthetic asssociations in general. I have also seen several families where members experience different forms of syanesthesia, further suggesting that genetic variants can broadly predispose a person to experience synaesthesia, and that other factors may shape the specific associations that form.
Interested? A short reading list:
- General audience
- “Blended senses: understanding synaesthesia”, by Amanda Tilot, in Science in School.
- The Frog Who Croaked Blue: Synaesthesia and the mixing of the senses, by Jamie Ward
- Wednesday is Indigo Blue, by Richard Cytowic and David Eagleman
- Born on a Blue Day, by Daniel Tammet
- Research studies and reviews
- Newell, F. N. & Mitchell, K. J. Multisensory integration and cross-modal learning in synaesthesia: A unifying model. Neuropsychologia 88, 140–150 (2016).
- Tomson, S. et al. The genetics of colored sequence synesthesia: Suggestive evidence of linkage to 16q and genetic heterogeneity for the condition. Behav Brain Res 223, 48–52 (2011).
- Asher, J. E. et al. A Whole-Genome Scan and Fine-Mapping Linkage Study of Auditory-Visual Synesthesia Reveals Evidence of Linkage to Chromosomes 2q24, 5q33, 6p12, and 12p12. * Am J Hum Genet* 84, 279–285 (2009).