Artifact Identification Flashcards
6 cards from real EEG practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Artifact Identification flashcards as text
Sweat artifact on EEG typically presents as:
Answer: Very slow, undulating baseline shifts in the delta or sub-delta frequency range
Sweat artifact produces slow, rolling baseline undulations (typically <1 Hz) caused by changes in skin potential and electrode impedance from perspiration, often appearing as very slow waves that can obscure underlying EEG activity.
How can chewing artifact be distinguished from rhythmic temporal seizure activity?
Answer: Chewing artifact produces bilateral, symmetrical, rhythmic EMG bursts with a chewing rhythm (1-2 Hz) that correlates with observed jaw movements
Chewing artifact produces bilateral, relatively symmetrical EMG activity at temporal electrodes with a rhythmic pattern matching jaw movements, while temporal seizure activity typically shows evolving frequency and may have associated epileptiform features.
Which EEG channel is most useful for identifying and distinguishing eye movement artifacts from frontal brain activity?
Answer: Dedicated EOG (electrooculogram) channels
Dedicated EOG channels (typically placed above and below one eye, and at the outer canthi) directly record eye movements and blinks, allowing definitive distinction from frontal cerebral activity.
Electrode bridging occurs when:
Answer: Two nearby electrodes are electrically connected by excess conductive gel, producing nearly identical waveforms
Electrode bridging occurs when excessive conductive gel spreads between adjacent electrodes, creating a low-resistance pathway that makes both electrodes record essentially the same signal, reducing spatial resolution.
Intravenous drip artifact may appear on EEG as:
Answer: Periodic, rhythmic slow transients corresponding to the drip rate, typically at one or a few channels near the IV site
IV drip artifact produces periodic transients at the frequency of the drip rate, typically affecting electrodes near the IV site. Each drop creates a small electrical potential change detected by nearby electrodes.
What is the best approach when an artifact cannot be eliminated during recording?
Answer: Document the artifact's characteristics, suspected source, and affected channels in the technical notes while continuing the recording
When artifacts cannot be eliminated, the technologist should thoroughly document them in the technical notes (type, source, affected channels, timing) while continuing the recording, providing the interpreter with essential information for accurate reading.