A telltale signature of consciousness has been detected that takes us a step closer to disentangling the brain activity underlying conscious and unconscious brain processes.

It turns out that there is a similar pattern of neural activity each time we become conscious of the same picture, but not if we process information from the image unconsciously. These contrasting patterns of activity can now be detected via brain scans, and could one day help determine if patients with brain damage are conscious. They might even be used to probe consciousness in animals.

via Signature of consciousness captured in brain scans – life – 12 November 2009 – New Scientist.