Changing from American to British accent.

Yes, this almost always happens to me when I watch British programs (I am Canadian). Interesting to know that I am not the only one. I don't find I pick up any specific British accent, but I find that I pronounce different words in different accents.

I find myself doing this sometimes, especially after I have watch British shows. I have been told by my Dad and brother that I was talking like a British person and to talk normal!

I am from the U.S.

I didn't necissarily switch accents...

But I spent about two years in London for work and in about the first three weeks I started having difficulty pronouncing words.  I'd trip over my tongue often and started chopping off syllables.  It ended after a while but for some time I had to consciously focus on enunciation to get anything out.

When I came back home for Christmas to my family my mother noted that I had dropped the harsh 'a' sound and was saying 'ah' instead.  But other than that I picked up my old Washingtonian accent immediately back in America.

My accent was definitely effected by exposure to British accents but it was more of a watering down than anything else.  I'll never get a pure British accent (and I'm not trying to) and British people can still always tell that I'm an American.

I don't know whether or not you're talking about native or non-native English speakers though.  Because you can learn BritE and learn AmE and transfer between the two as well.  It just depends I suppose.