Bilinguals switching between codes have been interesting cases for research in sociolinguistics and the ethnography of communication. For instance, many bilinguals identify one language as the "we-code" and the other language as the "they-code," switching according to both conversational and social contexts. This phenomenon leads to fascinating studies of linguistic communities, language ideology, and social identity.
A recent study by Kuan Kho and others at the Rudolf Magnus Institute in Utrecht sheds some light on the neurological basis of code-switching as bilingual patients treated for epilepsy would switch involuntarily from one code to the next.
BPS RESEARCH DIGEST: Tongue-tied: When bilinguals switch languages involuntarily
This could lead to interesting conversations between linguistic anthropologists and other language scientists, including neuroscientists.