What is a eeg
Such intracranial recordings provide measures of cortical dynamics at small spatial scales, dependent on electrode size. EEG is the only widely available technology with sufficient temporal resolution to follow these quick dynamic changes.ĮEG can be recorded using electrodes placed inside the skull to study nonhuman mammals or human epilepsy patients. Cortical processes involve electrical signaling between neurons that change over many times in the 10 ms (0.01 s) range. The outer brain layer is the cerebral cortex, believed to be largely responsible for cognition: perception, memory, thinking, emotions, actions, and behaviors. Human electroencephalography (EEG) provides a convenient, but often opaque, ‘window on the mind,’ allowing observations of electrical processes near the brain surface. Nunez, in Encyclopedia of Human Behavior (Second Edition), 2012 Window on the Mind
WHAT IS A EEG PORTABLE
Traditionally, EEG is performed in well-controlled laboratory settings however, portable monitoring and long-term monitoring have also become common with recent advances in technology. EEG is also used in a variety of research protocols. EEG can be used in clinical settings to diagnose CNS pathology and is included in PSG, along with multiple other physiological parameters to distinguish sleep and wake, and to identify sleep stages. EEG can also differentiate between wakefulness, sleep, coma, and CNS silence (brain death). When used in polysomnography (PSG), EEG allows for both microanalysis (e.g., specific frequencies and waveforms) and macroanalysis (e.g., whether the patient is awake or asleep, whether pathologies are present) of sleep. Other analyses include describing the morphology and temporal distribution of events. EEG allows for analysis of data in terms of both time (i.e., frequency) and voltage (i.e., amplitude) domains. EEG recording requires care and attention to detail regarding electrode application, equipment preparation, and the recognition and elimination of artifact. It is the only measure that allows differentiation within the spectrum of consciousness. Casseres, in Encyclopedia of Sleep, 2013 AbstractĮlectroencephalography (EEG) provides a window into the dynamic function of the central nervous system (CNS).