Audience members at a university dance recital provoked a viral – and visceral – reaction after a social media post with 10 million views showed them taking part in a brain-reading experiment while watching the performance.But the scientists monitoring brain responses during the show have come out to explain the nature of the experiment and the purpose of the volunteers’ electrode-covered “hats” worn in the theatre that social media commenters said were unsettling and had triggered “goosebumps”...