Brain scans created using functional MRI consist of a series of images in which different areas light up with varying intensity at different times. These can be used to determine which parts of the brain are active during a particular task.
To turn such scans into music, philosopher Dan Lloyd at Trinity College in Hartford, Connecticut, identified regions that become active together and assigned each of these groups a different pitch. He then created software that analyses a series of scans and generates the notes at these pitches as the corresponding brain areas light up. Each note is played at a volume that corresponds to the intensity of activity.
When Lloyd fed the software a set of scans of his own brain taken as he switched between driving a virtual-reality car and resting, he found that he could detect the switch-over in the sounds.
Lloyd then gave the software scans taken from volunteers with dementia and schizophrenia, and from healthy volunteers. The brains of people with schizophrenia switched between low and high activity more erratically than healthy brains, allowing the two types of brain to be distinguished by sound alone.
Reminds me of the intro to "Your Time Is Gonna Come" by Led Zeppelin: