Practice Test GeeksEEG - Electroencephalography Practice Test
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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

  1. Which artifact appears as a regular, rhythmic waveform at the same frequency as the patient's heart rate?

    Answer: Pulse artifact (ECG artifact)

    Pulse artifact appears as rhythmic waveforms synchronous with the cardiac cycle, caused by electrode placement over a pulsating blood vessel or by ballistocardiographic effect.

  2. Eye blink artifact is primarily seen at which electrode positions?

    Answer: Frontal electrodes (Fp1, Fp2)

    Eye blink artifact produces high-amplitude positive deflections most prominent at Fp1 and Fp2 because the cornea (positive pole of the eye dipole) moves upward toward these frontopolar electrodes during blinking.

  3. What is the most effective method for reducing 60 Hz electrical interference artifact?

    Answer: Ensuring all electrode impedances are balanced and below 5 kOhm

    Balanced, low impedances (below 5 kOhm) allow the differential amplifier to effectively reject common-mode 60 Hz noise. Impedance imbalance between electrodes is the primary cause of excessive 60 Hz artifact.

  4. Glossokinetic artifact is caused by movement of which structure?

    Answer: The tongue, which acts as an electrical dipole

    The tongue has a tip-negative, base-positive electrical dipole. Tongue movements generate slow potentials that are transmitted to scalp electrodes, particularly in frontal and temporal regions.

  5. An electrode pop artifact on EEG is characterized by:

    Answer: Abrupt, high-amplitude deflection confined to a single channel

    Electrode pop appears as a sudden, high-amplitude spike-like deflection isolated to one channel, caused by abrupt impedance change at a single electrode due to drying gel, poor contact, or mechanical disturbance.

  6. Muscle artifact from the temporalis muscle can be distinguished from beta activity because muscle artifact typically:

    Answer: Shows frequencies above 20 Hz with irregular sharp morphology maximal at temporal electrodes

    Temporalis muscle (EMG) artifact produces high-frequency (typically >20 Hz) irregular, sharp activity maximal at temporal and frontal electrodes, which can obscure underlying brain activity in those regions.