Propofol and ketamine are both general anaesthetics but produce markedly different states of consciousness. Propofol induces a deeply unconscious state with few or no dream reports, whereas ketamine anaesthesia is frequently followed by reports of vivid dreams. The abstract contrasts these two drugs' effects on awareness and dreaming, highlighting that different anaesthetics can produce distinct subjective experiences even when both cause loss of consciousness.
Measures that distinguish conscious from unconscious brain states may also be influenced by attentional load and cognitive resource use within conscious states. Testing several proposed measures, the study examines whether they are modulated by changes in attention and cognitive demands, which has rarely been tested before. The findings suggest that these measures are not solely markers of consciousness but can vary with attentional load within conscious states.