The usage of the term synesthesia in art should, therefore, be differentiated from neurological synesthesia in scientific research. Synesthesia is by no means unique to artists or musicians. Only in the last decades have scientific methods become available to assess synesthesia in persons. For synesthesia in artists before that time one has to interpret (auto)biographical information. For instance, there has been debate on the neurological synesthesia of historical artists like Kandinsky and Scriabin (cf. Jewanski & Sidler 2006, Ione 2004, Dann 1999, Galeyev 2001).