Consciousness is understood through its neuroanatomic basis, with recent studies identifying EEG, ERP, and fMRI signals that predict aspects of conscious experience. Disorders affecting the reticular activating system alter the level of consciousness, while cortical disorders such as seizures, migraines, strokes, and dementia disrupt phenomenal consciousness. The memory theory of consciousness offers a new explanation of phenomenal consciousness that may better account for experimental studies and clinical experience. Despite advances in understanding the physiology underlying both level and phenomenal consciousness, the complete neurobiological basis remains unknown.
The frontal cortex is involved in many functions linked to consciousness, and disorders that damage frontal brain areas or networks can alter conscious experience. This review examines how frontal disorders affect consciousness, considering competing theories: some hold that the frontal cortex is necessary for consciousness, others emphasize posterior cortical regions, and the Memory Theory of Consciousness proposes that consciousness depends on modality-specific localization throughout the brain. The authors argue that frontal disorders do not abolish consciousness but can disrupt conscious abilities including sustained attention, working memory, problem-solving, complex thought, executive function, response inhibition, decision-making, and goal-oriented behavior. Understanding this relationship has significant scientific, clinical, and societal implications.