I question whether it is completely accurate to think of the philosophical meaning of consciousness as being switched-on or switched-off. It may be that, once consciousness is switched-on, it is then found in degrees in animals we deem conscious. In which case, consciousness is more like a switched-on rheostat, rather than a simple on–off switch. Christian de Quincey (2006) gives a list of what...

Scientists studying consciousness are attempting to identify correlations between measurements of consciousness and the physical world. Consciousness can only be measured through first-person reports, which raises problems about the accuracy of first-person reports, the possibility of non-reportable consciousness and the causal closure of the physical world. Many of these issues could be resolv...

Imaging in Acute Portal Systemic Shunt Encephalopathy Caused by Primary Biliary Cirrhosis Hepatic encephalopathy (HE) is 1 cause of a disturbance of consciousness, most cases being associated with liver cirrhosis. There are 2 previous reports of diffusion-weighted imaging (DWI) of the brain in acute HE. We now report a rare case of shunt encephalopathy caused by primary biliary cirrhosis (PBC) ...