A historical review of consciousness and its disorders.
Handbook of clinical neurology January 1, 2025 G Bryan Young, Loretta Norton
Consciousness depends on the brain and has two main aspects: wakefulness and awareness. Awareness includes perception, abstract thought, selection, judgment, motivation, and emotion. The brain can process information and influence behavior without conscious awareness. Advances in science and technology have deepened understanding of the neural functions and brain region interactions underlying conscious experience. Studies of disorders from brain death to delirium have shaped knowledge of regional and global brain functions. Behavioral responses alone are insufficient to determine conscious level; some unresponsive-wakeful patients retain cognitive capacity detectable by fMRI and electrophysiology. Much remains unknown about how full awareness and self-awareness arise and how best to assess and manage disorders of consciousness.