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ABRET EEG EXAMINATION 2026-2027 BANK QUESTIONS
WITH DETAILED VERIFIED ANSWERS EXAM QUESTIONS
WILL COME FROM HERE (100% CORRECT ANSWERS A+
GRADED
1. Which of the following is a contraindication for the activation
procedure of hyperventilation?
A) History of absence seizures
B) Recent intracranial hemorrhage
C) Patient age of 10 years
D) Fasting blood glucose of 95 mg/dL
Answer: B
Explanation: Hyperventilation leads to cerebral vasoconstriction and
reduced cerebral blood flow. In a patient with a recent intracranial
hemorrhage, this alteration in vascular dynamics could precipitate re-
bleeding or exacerbate existing vascular compromise. While absence
seizures can be activated by hyperventilation, this is a diagnostic goal,
not a contraindication.
2. The international 10-20 system uses which anatomical landmarks to
ensure proportional electrode placement?
A) Nasion, inion, and preauricular points
B) Nasion, vertex, and mastoid processes
C) Glabella, inion, and zygomatic arches
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D) Nasion, bregma, and lambda
Answer: A
Explanation: The 10-20 system relies on the nasion (bridge of the nose),
inion (occipital protuberance), and the left and right preauricular points
(anterior to the ear canals) as the foundational landmarks. These points
define the skull's midline and coronal circumference, from which
proportional distances of 10% or 20% are measured for precise,
reproducible electrode placement.
3. A low-frequency filter setting of 1 Hz corresponds to a time constant
of approximately:
A) 0.016 seconds
B) 0.16 seconds
C) 1.6 seconds
D) 16 seconds
Answer: B
Explanation: The time constant (TC) is inversely related to the low-
frequency filter (LFF) cutoff frequency (fc) by the formula TC = 1/(2πfc).
For clinical use, the simplified relationship TC ≈ 0.16 / fc is used.
Therefore, for an LFF of 1 Hz, TC = 0. = 0.16 seconds.
4. During a recording, a 60 Hz artifact is observed in all channels. The
technologist should first:
A) Increase the high-frequency filter to 70 Hz
B) Check the patient's head wrap for tightness
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C) Check the ground electrode impedance
D) Activate the 60 Hz notch filter and continue recording
Answer: C
Explanation: A 60 Hz artifact present across all channels is most likely
due to a high-impedance or disconnected ground electrode, which
compromises the amplifier's common-mode rejection. The first and
most crucial step is to check and correct the ground electrode's
contact. Applying a notch filter without investigating the cause may
mask a correctable technical problem.
5. A waveform with a voltage of 75 microvolts and a duration of 80
milliseconds is best characterized as:
A) Spike
B) Sharp wave
C) Slow wave
D) Paroxysmal fast activity
Answer: B
Explanation: The defining characteristic differentiating a spike from a
sharp wave is duration. A spike has a duration of 20 to less than 70
milliseconds. A sharp wave has a duration of 70 to 200 milliseconds.
With a duration of 80 ms, this waveform falls squarely within the
criteria for a sharp wave.
6. The primary generator of the posterior dominant alpha rhythm is
located in the:
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A) Thalamus
B) Occipital cortex
C) Thalamocortical networks
D) Reticular activating system
Answer: C
Explanation: The posterior dominant rhythm is not generated in
isolation by either the thalamus or the cortex. It arises from the
dynamic, reciprocal interaction of thalamocortical relay neurons and
cortical pyramidal cells, specifically within occipital thalamocortical
networks. The reticular activating system modulates arousal and
desynchronizes this rhythm.
7. In a bipolar montage, an end-of-chain electrode becomes
contaminated with a large amount of sweat artifact. What is the most
likely finding on the recording?
A) The artifact appears in all channels equally
B) The artifact is localized to the single bad electrode
C) The artifact appears maximally in the channel pair that includes the
contaminated electrode
D) The artifact appears in the last channel of the chain only
Answer: C
Explanation: In a bipolar montage, each channel measures the voltage
difference between two adjacent electrodes. If the end-of-chain
electrode (which is only in one pair) has a large artifact, that voltage will
be subtracted from the signal of the adjacent electrode. Therefore, the
ABRET EEG EXAMINATION 2026-2027 BANK QUESTIONS
WITH DETAILED VERIFIED ANSWERS EXAM QUESTIONS
WILL COME FROM HERE (100% CORRECT ANSWERS A+
GRADED
1. Which of the following is a contraindication for the activation
procedure of hyperventilation?
A) History of absence seizures
B) Recent intracranial hemorrhage
C) Patient age of 10 years
D) Fasting blood glucose of 95 mg/dL
Answer: B
Explanation: Hyperventilation leads to cerebral vasoconstriction and
reduced cerebral blood flow. In a patient with a recent intracranial
hemorrhage, this alteration in vascular dynamics could precipitate re-
bleeding or exacerbate existing vascular compromise. While absence
seizures can be activated by hyperventilation, this is a diagnostic goal,
not a contraindication.
2. The international 10-20 system uses which anatomical landmarks to
ensure proportional electrode placement?
A) Nasion, inion, and preauricular points
B) Nasion, vertex, and mastoid processes
C) Glabella, inion, and zygomatic arches
,2|Page
D) Nasion, bregma, and lambda
Answer: A
Explanation: The 10-20 system relies on the nasion (bridge of the nose),
inion (occipital protuberance), and the left and right preauricular points
(anterior to the ear canals) as the foundational landmarks. These points
define the skull's midline and coronal circumference, from which
proportional distances of 10% or 20% are measured for precise,
reproducible electrode placement.
3. A low-frequency filter setting of 1 Hz corresponds to a time constant
of approximately:
A) 0.016 seconds
B) 0.16 seconds
C) 1.6 seconds
D) 16 seconds
Answer: B
Explanation: The time constant (TC) is inversely related to the low-
frequency filter (LFF) cutoff frequency (fc) by the formula TC = 1/(2πfc).
For clinical use, the simplified relationship TC ≈ 0.16 / fc is used.
Therefore, for an LFF of 1 Hz, TC = 0. = 0.16 seconds.
4. During a recording, a 60 Hz artifact is observed in all channels. The
technologist should first:
A) Increase the high-frequency filter to 70 Hz
B) Check the patient's head wrap for tightness
,3|Page
C) Check the ground electrode impedance
D) Activate the 60 Hz notch filter and continue recording
Answer: C
Explanation: A 60 Hz artifact present across all channels is most likely
due to a high-impedance or disconnected ground electrode, which
compromises the amplifier's common-mode rejection. The first and
most crucial step is to check and correct the ground electrode's
contact. Applying a notch filter without investigating the cause may
mask a correctable technical problem.
5. A waveform with a voltage of 75 microvolts and a duration of 80
milliseconds is best characterized as:
A) Spike
B) Sharp wave
C) Slow wave
D) Paroxysmal fast activity
Answer: B
Explanation: The defining characteristic differentiating a spike from a
sharp wave is duration. A spike has a duration of 20 to less than 70
milliseconds. A sharp wave has a duration of 70 to 200 milliseconds.
With a duration of 80 ms, this waveform falls squarely within the
criteria for a sharp wave.
6. The primary generator of the posterior dominant alpha rhythm is
located in the:
, 4|Page
A) Thalamus
B) Occipital cortex
C) Thalamocortical networks
D) Reticular activating system
Answer: C
Explanation: The posterior dominant rhythm is not generated in
isolation by either the thalamus or the cortex. It arises from the
dynamic, reciprocal interaction of thalamocortical relay neurons and
cortical pyramidal cells, specifically within occipital thalamocortical
networks. The reticular activating system modulates arousal and
desynchronizes this rhythm.
7. In a bipolar montage, an end-of-chain electrode becomes
contaminated with a large amount of sweat artifact. What is the most
likely finding on the recording?
A) The artifact appears in all channels equally
B) The artifact is localized to the single bad electrode
C) The artifact appears maximally in the channel pair that includes the
contaminated electrode
D) The artifact appears in the last channel of the chain only
Answer: C
Explanation: In a bipolar montage, each channel measures the voltage
difference between two adjacent electrodes. If the end-of-chain
electrode (which is only in one pair) has a large artifact, that voltage will
be subtracted from the signal of the adjacent electrode. Therefore, the
