Alertness and attention: basic science and electrophysiologic correlates.

There has been much research in the electrophysiologic correlates of alertness and attention, but it is fragmented into many subfields. This article integrates current knowledge across multiple disciplines and methodologies to provide a broad overview of alertness and attention. First, terms that are related to alertness and attention are clarified. Then, there is a discussion of basic neuroscience, human neurophysiology, and clinical fields that impact on alertness and attention. Areas discussed include thalamic and neurotransmitter-specific ascending pathways. EEG, event-related potentials, and both physiologic and pathologic states of decreased alertness or attention.