Propofol-induced unconsciousness is linked to decreased connectivity within frontoparietal networks (the default-mode and executive-control networks) and between the thalamus and these networks, with a negative correlation between thalamic and cortical activity emerging during unconsciousness. In contrast, connectivity in low-level sensory cortices (auditory and visual networks) is preserved, including their thalamocortical connections. Loss of consciousness is associated with a breakdown of cross-modal interactions between visual and auditory networks. These findings suggest that unconsciousness results from disrupted communication between sensory and higher-order frontoparietal cortices, preventing conscious perception.
Attitudes about whether mind and brain are separate or the same thing vary by age, gender, and religious belief. Two surveys—one of university students in Edinburgh (250 people) and another of health-care workers and the public in Liège (1,858 people)—found that dualistic views (seeing mind and brain as distinct) were common. In the Liège survey, younger participants, women, and those with religious beliefs were more likely to endorse separation of mind and brain, survival of a spiritual part after death, and the existence of a soul distinct from the body. Religious belief was the strongest predictor of dualism. Over a third of medical and paramedical professionals also regarded mind and brain as separate, even though most health-care workers rejected that distinction.