ABRET EEG EXAM TEST BANK 200 QUESTIONS AND CORRECT
ANSWERS WITH DETAILED RATIONALES COVERING THE RECENT
TAKEN QUESTIONS GUARANTEE HIGH PASS MARK
1. The international 10–20 system is based on measurements taken from:
A. The ears to the nose
B. The nasion and inion and between preauricular points
C. The top of the head to the chin
D. The vertex to the mastoids
Rationale: The 10–20 system divides the nasion–inion and preauricular points distances into
10% and 20% intervals for electrode placement.
2. In the 10–20 system, Fp1 is located:
A. Midline frontal
B. Left frontal polar region
C. Right frontal region
D. Central midline
Rationale: “Fp” = frontal polar; odd numbers = left hemisphere, even numbers = right.
3. The normal adult alpha rhythm frequency range is:
A. 2–4 Hz
B. 4–7 Hz
C. 8–13 Hz
D. 13–30 Hz
Rationale: Alpha rhythm (8–13 Hz) is dominant in posterior head regions during relaxed
wakefulness with eyes closed.
4. Alpha rhythm is most prominent when:
A. Eyes are open
B. The patient is hyperventilating
C. Eyes are closed and the patient is relaxed
D. The patient is sleeping
,Rationale: Alpha attenuates with eye opening and mental effort, strongest in relaxed
wakefulness.
5. The calibration pulse of 50 µV should produce a deflection of:
A. 5 mm
B. 7 mm
C. 10 mm
D. 15 mm
Rationale: Sensitivity 10 µV/mm → 50 µV signal = 5 mm × 2 = 10 mm deflection.
6. A low-frequency filter of 1 Hz will:
A. Attenuate slow waves
B. Enhance slow activity
C. Eliminate fast frequencies
D. Eliminate muscle artifact
Rationale: Low-frequency (high-pass) filters attenuate frequencies below the cutoff, reducing
slow activity.
7. The main effect of increasing sensitivity is:
A. Waves appear smaller
B. Waves appear larger
C. Time base slows down
D. Filters change
Rationale: Higher sensitivity value (e.g., 10 µV/mm) means less deflection — waves look
smaller.
8. The best way to identify 60 Hz artifact is:
A. Fast, low-amplitude, rhythmic activity
B. High amplitude, slow waves
C. Sharp transients
D. Irregular muscle bursts
,Rationale: 60 Hz interference appears as regular, fine, high-frequency activity across all
channels.
9. Hyperventilation is contraindicated in patients with:
A. Epilepsy
B. Stroke or recent intracranial hemorrhage
C. Absence seizures
D. Sleep disorders
Rationale: Hyperventilation reduces cerebral blood flow, which can worsen ischemic injury.
10. Photic stimulation should be performed:
A. Only with eyes closed
B. Only at 10 Hz
C. At varying frequencies from 1–30 Hz
D. During sleep
Rationale: 1–30 Hz flash frequencies assess for photoparoxysmal response and reactivity.
11. The central sulcus separates:
A. Frontal and parietal lobes
B. Parietal and occipital lobes
C. Temporal and frontal lobes
D. Parietal and temporal lobes
Rationale: The central sulcus (Rolandic fissure) divides motor (frontal) and sensory (parietal)
cortex.
12. Beta activity is typically found:
A. Posteriorly
B. Centrally and anteriorly
C. Temporally only
D. Diffusely during deep sleep
Rationale: Beta (13–30 Hz) predominates frontocentrally, often enhanced by benzodiazepines.
, 13. A breach rhythm occurs over:
A. Skull defect site
B. Tumor
C. Hemorrhage
D. Sleep spindles
Rationale: Loss of skull attenuation enhances cortical potentials → high-amplitude, fast breach
rhythm.
14. Muscle artifact primarily affects which frequency range?
A. 0.1–4 Hz
B. 4–7 Hz
C. 13–30 Hz
D. 20–80 Hz
Rationale: EMG artifact = fast, irregular, high-frequency activity (20–80 Hz).
15. What is the most common sleep EEG pattern in stage II sleep?
A. Alpha rhythm
B. K complexes and sleep spindles
C. Vertex waves
D. Delta activity
Rationale: Stage II sleep shows K complexes and spindles (12–14 Hz).
16. Electrode impedance should be:
A. < 10,000 ohms and equal between electrodes
B. > 10,000 ohms
C. 50,000 ohms
D. Not important
Rationale: Balanced impedances under 10 kΩ prevent artifact and improve signal fidelity.
17. Which waveform is normal in infants but abnormal in adults?
A. Delta
B. Lambda
ANSWERS WITH DETAILED RATIONALES COVERING THE RECENT
TAKEN QUESTIONS GUARANTEE HIGH PASS MARK
1. The international 10–20 system is based on measurements taken from:
A. The ears to the nose
B. The nasion and inion and between preauricular points
C. The top of the head to the chin
D. The vertex to the mastoids
Rationale: The 10–20 system divides the nasion–inion and preauricular points distances into
10% and 20% intervals for electrode placement.
2. In the 10–20 system, Fp1 is located:
A. Midline frontal
B. Left frontal polar region
C. Right frontal region
D. Central midline
Rationale: “Fp” = frontal polar; odd numbers = left hemisphere, even numbers = right.
3. The normal adult alpha rhythm frequency range is:
A. 2–4 Hz
B. 4–7 Hz
C. 8–13 Hz
D. 13–30 Hz
Rationale: Alpha rhythm (8–13 Hz) is dominant in posterior head regions during relaxed
wakefulness with eyes closed.
4. Alpha rhythm is most prominent when:
A. Eyes are open
B. The patient is hyperventilating
C. Eyes are closed and the patient is relaxed
D. The patient is sleeping
,Rationale: Alpha attenuates with eye opening and mental effort, strongest in relaxed
wakefulness.
5. The calibration pulse of 50 µV should produce a deflection of:
A. 5 mm
B. 7 mm
C. 10 mm
D. 15 mm
Rationale: Sensitivity 10 µV/mm → 50 µV signal = 5 mm × 2 = 10 mm deflection.
6. A low-frequency filter of 1 Hz will:
A. Attenuate slow waves
B. Enhance slow activity
C. Eliminate fast frequencies
D. Eliminate muscle artifact
Rationale: Low-frequency (high-pass) filters attenuate frequencies below the cutoff, reducing
slow activity.
7. The main effect of increasing sensitivity is:
A. Waves appear smaller
B. Waves appear larger
C. Time base slows down
D. Filters change
Rationale: Higher sensitivity value (e.g., 10 µV/mm) means less deflection — waves look
smaller.
8. The best way to identify 60 Hz artifact is:
A. Fast, low-amplitude, rhythmic activity
B. High amplitude, slow waves
C. Sharp transients
D. Irregular muscle bursts
,Rationale: 60 Hz interference appears as regular, fine, high-frequency activity across all
channels.
9. Hyperventilation is contraindicated in patients with:
A. Epilepsy
B. Stroke or recent intracranial hemorrhage
C. Absence seizures
D. Sleep disorders
Rationale: Hyperventilation reduces cerebral blood flow, which can worsen ischemic injury.
10. Photic stimulation should be performed:
A. Only with eyes closed
B. Only at 10 Hz
C. At varying frequencies from 1–30 Hz
D. During sleep
Rationale: 1–30 Hz flash frequencies assess for photoparoxysmal response and reactivity.
11. The central sulcus separates:
A. Frontal and parietal lobes
B. Parietal and occipital lobes
C. Temporal and frontal lobes
D. Parietal and temporal lobes
Rationale: The central sulcus (Rolandic fissure) divides motor (frontal) and sensory (parietal)
cortex.
12. Beta activity is typically found:
A. Posteriorly
B. Centrally and anteriorly
C. Temporally only
D. Diffusely during deep sleep
Rationale: Beta (13–30 Hz) predominates frontocentrally, often enhanced by benzodiazepines.
, 13. A breach rhythm occurs over:
A. Skull defect site
B. Tumor
C. Hemorrhage
D. Sleep spindles
Rationale: Loss of skull attenuation enhances cortical potentials → high-amplitude, fast breach
rhythm.
14. Muscle artifact primarily affects which frequency range?
A. 0.1–4 Hz
B. 4–7 Hz
C. 13–30 Hz
D. 20–80 Hz
Rationale: EMG artifact = fast, irregular, high-frequency activity (20–80 Hz).
15. What is the most common sleep EEG pattern in stage II sleep?
A. Alpha rhythm
B. K complexes and sleep spindles
C. Vertex waves
D. Delta activity
Rationale: Stage II sleep shows K complexes and spindles (12–14 Hz).
16. Electrode impedance should be:
A. < 10,000 ohms and equal between electrodes
B. > 10,000 ohms
C. 50,000 ohms
D. Not important
Rationale: Balanced impedances under 10 kΩ prevent artifact and improve signal fidelity.
17. Which waveform is normal in infants but abnormal in adults?
A. Delta
B. Lambda
