In my talk I will review the structural and functional imaging studies on
synaesthesia. Since many imaging studies have focused on grapheme-colour
synaesthesia, the emphasis of my talk will reflect this, and so I will give a summary
of the current knowledge about structural and functional brain differences in
grapheme-colour synaesthetes in particular. Moreover, I will examine how
these structural and functional imaging results might inform current theories
about the neural mechanisms of synaesthesia.
Initially, functional imaging studies concentrated on the phenomenology
of synaesthetic experiences: activation of colour-processing areas in the brain
confirmed the “perceptual reality” of these experiences. Further studies ex-
plored the neural correlate of individual differences in synaesthesia with the
help of functional imaging. Recently, modern network analysis methods have
been applied in the field of synaesthesia to assess the neural network
architecture during rest and task performance in grapheme-colour synaesthetes.
These advances in functional imaging were paralleled by studies using
structural imaging methods, like voxel-based morphometry (VBM) and
diffusion tensor imaging (DTI) to explore grey and white matter differences in
synaesthesia, respectively.
Finally, I will also provide a critical discussion of the kinds of limitations
found in previous approaches to studying synaesthetic brain differences, and I
discuss future perspectives and challenges that structural and functional
neuroimaging research in synaesthesia will face.
Prof. Dr. Peter Weiss-Blankenhorn studied medicine at the Heinrich-Heine-
University Düsseldorf. After research projects on Parkinson’s disease in
Arizona, USA, and on apraxia in Lyon, France, he was trained in neurology at the
University Hospitals in Düsseldorf and Aachen, Germany. As a board-certified
neurologist he works in the Institute of Neuroscience and Medicine (INM-3)
of the Research Centre Jülich (FZJ), Germany, leading the group “Motor Cognition”.
Since 2010, he is also professor of cognitive neurology at the University
of Cologne, Germany. In addition to synaesthesia, his scientific interests in the
area of cognitive neurology are focused on the neural basis of cognitive deficits
after stroke using structural and functional imaging. This translational research
aims at the development of new, innovative therapies for neurorehabilitation.