National and cultural differences in synesthetic words are examined based on universal physiological characteristics. First, there are differences regarding the associative network: although the physiology of synesthesia involves an unconditioned reflex, the same external stimulus may have different cultural associations for different nations. Second, Eastern and Western languages differ in their word formation patterns for synesthetic terms, with the former (e.g., Chinese) using compounding and the latter mostly utilizing semantic transfer. (LLBA 2003, vol. 37, n. 1)