conscious

Conscious is an adjective describing the state of being aware of and able to think about oneself and the surrounding environment. A conscious person can report their thoughts, feelings, and surroundings, make intentional decisions, and act with deliberation. In everyday use, the term contrasts with unconscious or asleep, and with nonconscious processing, which refers to mental activities outside current awareness.

The word derives from Latin conscientia, from con- "together" and scire "to know." In medical contexts, consciousness denotes wakefulness and responsiveness. Levels of consciousness range from fully alert to coma; loss of consciousness can occur in syncope, head injury, or anesthesia. Conscious sedation and anesthesia are controlled states used in medical procedures.

In psychology and philosophy, consciousness is distinguished from unconscious processing. Modern cognitive science often separates phenomenal consciousness (the subjective experience of sensations and feelings) from access consciousness (the availability of information for reasoning and reporting). The study of consciousness also raises questions about the nature of experience, the mind-body problem, and the so-called hard problem of why and how subjective experience arises.

Neuroscientific work links conscious awareness to interactions among cortical networks and the thalamus, with varying global brain states evident in EEG and imaging studies. Throughout culture and religion, consciousness is central to discussions of self, agency, morality, and the possibility of non-human or artificial consciousness.