Practice Test GeeksEEG - Electroencephalography Practice Test
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Artifact Identification Flashcards

7 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 7 Artifact Identification flashcards as text

  1. A lateral eye movement artifact in a bipolar longitudinal montage will appear with opposite polarity at:

    Answer: F7 and F8

    Lateral eye movements produce opposite-polarity deflections at F7 and F8 because the corneal-retinal potential approaches one side and recedes from the other.

  2. Which of the following features best distinguishes tremor artifact from a true EEG rhythm?

    Answer: Tremor artifact has a fixed frequency matching the patient's tremor rate

    Tremor artifact mirrors the physiological tremor frequency (4–6 Hz for Parkinson's, 8–12 Hz for essential tremor) and correlates with observed limb movement.

  3. A technologist uses a short-time constant (high-pass filter increase) to reduce which type of artifact?

    Answer: Slow sweat artifact

    Increasing the high-pass (low frequency) filter shortens the time constant and attenuates slow, DC-shift sweat artifact.

  4. During sleep recording, repetitive, high-amplitude spike-like potentials appearing synchronously with each heartbeat across all leads are best identified as:

    Answer: Cardiac (EKG) artifact

    EKG artifact produces spike-like potentials synchronous with the R-wave, often mistaken for epileptiform discharges if the ECG channel is not reviewed.

  5. Which montage change is most useful for confirming that a suspected artifact is truly artifactual rather than cerebral?

    Answer: Switching between bipolar and referential montages

    True cerebral activity maintains consistent field distributions across montages, while artifacts often appear or disappear inconsistently when the montage is changed.

  6. A high-amplitude, sharply contoured discharge that appears only in a single channel and does not violate the "neighbor rule" of field spread is most likely:

    Answer: An electrode artifact

    True cerebral discharges have plausible electrical fields involving neighboring electrodes, so an isolated single-channel transient without field spread is likely artifactual.

  7. Photomyogenic (photomyoclonic) response, which can mimic a photoparoxysmal response, differs in that it:

    Answer: Is frontally predominant muscle artifact time-locked to each flash

    Photomyogenic response is a muscle artifact (frontalis/orbicularis) synchronized to each photic flash, whereas photoparoxysmal response is a true cerebral epileptiform discharge that may outlast the stimulus.