Most of the patients' groups that we study are recruited through clinics, but occasionally we make specific requests for people to come forward and these will appear here. In addition, our research often involves people with particular abilities or deficits in nervous system function, including tone deafness, colour blindness and synaesthesia (mixed sensations such as sounds that appear as colours). We are interested to hear from people with such conditions who would like to participate in our work. Please contact: ion@ncl.ac.uk