# Electroencephalography
**Domain:** Neurophysiology / Neural Interfaces
**Doc Type:** Scientific Concept Node
**Maturity:** Established
**Related:** [[Non-Invasive BCI]], [[BIDS-EEG]], [[Polysomnography]], [[DICOM Working Group 32]]
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## Definition
**Electroencephalography (EEG)** records voltage fluctuations at the scalp produced by coordinated neural activity. EEG offers millisecond-scale temporal resolution, relatively accessible hardware, and direct relevance to BCI control, sleep studies, epilepsy monitoring, evoked potentials, and longitudinal neurophysiology.
## Data requirements
Interpretation depends on electrode montage and positions, reference scheme, sampling rate, impedance, vigilance state, filters, events, medications, and acquisition device. [[wiki/BIDS-EEG|BIDS-EEG]] and [[wiki/ISO-IEC TS 27571-2026|ISO/IEC TS 27571:2026]] address complementary parts of that descriptive structure.