I have been travelling throughout Italy for the past several weeks and going between two languages-English and Italian. After several days and nights I have found myself dreaming in both languages. As I speak more and more Italian in waking day, I use more Italian in my dreams. I find myself and other characters speaking Italian and English. Interestingly, those people who only speak Italian (e.g. colleagues) are in my dreams only speaking Italian. Those who speak both Italian and English (e.g. my son) speak both languages in my dreams.
When I am in an English-only environment then my dreams include only English speaking characters, including myself. Of course this represents the continuity hypothesis which states that there is a continuity between waking day events and dream time imagery. However, there appears to be more complex circumstances here. As I transition between English and Italian, my dreams seem to be problem-solving, assimilating cultural differences, and helping me learn the language (I dream in both languages sometimes-as if I am teaching myself the language). Once again, the consciousness of dreaming reveals the complex layers of this mentation. Studies exploring cultural differences, language acquisition, and dreaming should yield fruitful results.