EEG Neuroanatomy and Physiology 2

Question 1

The posterior dominant rhythm (alpha rhythm) in a normal awake adult is generated primarily by which brain structure interaction?

Accepted Answer

Thalamocortical circuits involving the thalamus and occipital cortex

Answer

Brainstem reticular formation alone

Answer

Hippocampal-entorhinal connections

Answer

Basal ganglia output to frontal cortex

Question 2

Which cortical cell type is the primary generator of EEG signals recorded at the scalp?

Accepted Answer

Pyramidal neurons in cortical layers III and V

Answer

Stellate interneurons

Answer

Purkinje cells of the cerebellum

Answer

Motor neurons of the precentral gyrus

Question 3

The cortical area represented by electrode T3 (T7 in modified nomenclature) overlies which brain region?

Accepted Answer

Left mid-temporal region near the Sylvian fissure

Answer

Superior frontal gyrus

Answer

Right parietal lobe

Answer

Occipital pole

Question 4

What minimum area of synchronously active cortex is typically required to produce a detectable signal on scalp EEG?

Accepted Answer

6 cm²

Answer

1 cm²

Answer

25 cm²

Answer

100 cm²

Question 5

Delta activity (0.5-4 Hz) in a normal awake adult EEG is considered abnormal because it typically indicates:

Accepted Answer

Cortical dysfunction from structural or metabolic causes

Answer

Enhanced attention and concentration

Answer

Normal arousal response

Answer

Increased alpha variant activity

Question 6

The mu rhythm, typically recorded over the central regions, is characterized by:

Accepted Answer

An arch-shaped 8-13 Hz rhythm that attenuates with contralateral limb movement or movement planning

Answer

1-3 Hz delta activity that increases with movement

Answer

15-30 Hz beta activity maximal during sleep

Answer

Theta bursts during hyperventilation