01/18/2008 at 07:00 PM EST
has a new accessory to go with her pink wig: a British accent.
In the last several weeks, Spears, 26, has been videotaped numerous times trading her Louisiana twang for U.K. inflections.
"She had the English accent thing going the whole time" while shopping at Kitson last Thursday, according to a source. "It didn't stop."
Even when angry, the accent appears. On an L.A. shopping trip to Macy's on Jan. 13, she screamed at the paparazzi, "Get out of my G------ face!" – in a British accent.
So is it all in fun or has she flipped her pink wig?
"When someone has dissociative identity disorder" – formerly known as multiple personality disorder – "each identity is split off from the other," says L.A. psychologist Renee A. Cohen, who is not treating Spears. "Each identity would have its own name, memories, behavioral traits and emotional characteristics."
Cohen says the critical question is: "When Britney uses the British accent, or appears to take on another identity, does she know she's Britney Spears?"
"Otherwise, she could simply be behaving this way for attention, for sympathy, or any other reason," adds Cohen. "It's foolish to attempt to diagnose her without a formal evaluation."
One possible influence could be Spears's maternal grandmother, Lilian Bridges, who was originally from England.
Also, Spears's new beau, photographer Adnan Ghalib, grew up in Birmingham, England.
According to paparazzi who trail the singer around the clock, one thing is for sure: the pink wig means something's changing.
"When she puts on the pink wig, you just know something crazy is about to happen," said one paparazzo.