The woman who vomited on Lady GaGa says working with the singer is a ''powerful'' experience.

Performance artist Millie Brown - who rose to prominence after spewing green-coloured goo over Gaga during her gig at the South by Southwest festival in Texas last week - has no regrets about her controversial antics and stands by the superstar's experimental set.

She told ELLE magazine: ''I wasn't expecting so many reactions from it. It was quite a powerful performance. I love working with her because she really understands performance art. Both of our performances are different in many ways, but we both have the same core ideas. Working together is just quite powerful.''

The unusual performance was slammed by former bulimia sufferer Demi Lovato on Twitter, who maintained that Millie sticking her fingers down her throat and regurgitating on Gaga during her rendition of 'Swine' was glamorising eating disorders.

The British artist - whose vomit paintings sell for around $20,000 - believes that criticism is a vital part of her work, but insists she isn't promoting bulimia.

Millie added: ''I've seen a lot of positive and negative reactions to my work. I think they're both equally as important because it's causing people to really think about what art and freedom of expression means ...

''My performance is not a statement about eating disorders in any way. I think the whole bulimia thing - it's important for people to know that I'm not trying to promote it.''

Gaga has also brushed off the negative responses to the performance during her hour-long keynote speech at the event.

She quipped: ''Sometimes things that are really strange and feel really wrong can change the world.