Katy Perry praises 'genius' John Mayer

Singer Katy Perry has praised her boyfriend John Mayer's "genius" mind. She also says she wants to donate his brain to science and figure out "how all these sparks work".

"He literally is a genius, as is evident from his songwriting," contactmusic.com quoted Perry, 28, as saying.

"I always tell him, 'Darling, you know I'm going to have to give your mind to science after you've passed, because we're going to have to understand how all these sparks work,'" she added.