Arousal and normal conscious cognition

Abstract In the last decades, there has been a substantial increase in the knowledge of the anatomy, electrophysiology, and neurochemistry of the neuronal networks that generate normal conscious state during wakefulness. Consciousness is suppressed during deep nonrapid eye movement sleep, while a different type of consciousness arises during rapid eye movement sleep, where most dreams occur. Consciousness can be also suppressed or altered by different pathologies and drugs. In this chapter, focusing on the information provided by the electroencephalogram, we reviewed the most significant concepts of the electrocortical correlates of normal conscious cognition. Furthermore, we analyzed the electrocortical adjustments during physiological lost or alteration of consciousness and the effects produced by paradigmatic drugs.