By Cecylia Witkowski

 Synesthesia occurs when one sensory modality triggers another  A common synonym for Synesthesia is “Coloured Hearing”

2 how most people see the number 2 2 how people with synesthesia see it

 Three experiments conducted  Experiment 1 › 30 blocks of single spoken words (abstract and concrete) were alternated with single pure tones over a course of 5 min › Synesthetes were asked to describe the colour they experienced after each word  This data was used for experiment 3

 Experiment 2 › This was a control to see whether the presentation of words along with images of colour (Mondrians) would activate the same brain areas as synesthetes

 Experiment 3  Non-synesthetes would learn the word- colour combinations that synesthetes described  They were required to predict and imagine the colours associated with the words  Also required to re-test to obtain 100% accuracy

 Both the synesthetes and non- synesthetes displayed activation in all brain regions EXCEPT for the V4/V8 region › V4/V8 regions are gathered to be responsible for coloured vision  Even in Experiment 3, V4/V8 regions in non-synesthetes were not activated

 V4/V8 regions are still under much investigation for their absolute function and their relation to synesthesia  Despite training non-synesthetes, there was still no activation of V4/V8 regions › V4/V8 regions specific only to synesthetes?

 Due to activation, synesthetic colour experience is that of colour perception rather than imagery  There was no left V4/V8 activation in response to colours › Competition between normal colour perception and synesthetic perception

 Very well laid out  Had methodical approach to riddle out whether just association can procure ‘synesthesia-like’ effects  Interesting results › Synesthetes had regions activated that don’t in normal people  Usage of fMRI and PET scans to obtain accurate results

 Effectively used controls to determine synesthete and non-synesthete activations  Limited number of participants › 13 synesthetes › 27 controls › All female

 More participants › Variation in gender (not just females)  Vary in testing such that controls would see a word in colour, then repeated again without colour and test to see whether association will occur