University of Pittsburgh researchers have shown with brain scans what many insomniacs already report about their sleep: that it is disturbed by wandering thoughts, self-reflection and heightened self-attention, reports TribLive.

“What we found is that the people with insomnia have regions of their brain that seem to not shut off as completely when they’re asleep,” Buysse said.

The study, which included 44 people with insomnia and 40 without it, strengthens evidence from a similar study at Pitt that included 6 people with insomnia and 14 without it, he said. The study hasn’t proven a cause-and-effect connection between the brain activity and insomnia, Buysse said. The brain activity could be an effect of changed thought patterns, or vice versa.