Electroencephalography (EEG) Exam
Questions and Answers 100% Pass
What is an EEG (electroencephalograph)? - ✔✔Electroencephalography (EEG) is a
method of detecting neural activity by placing electrodes on the scalp.
EEG recorded at the scalp is non-invasive - however, it is also possible to record intra-
cranial EEG by measuring activity directly at the exposed cortex.
EEG is cheap and (relatively) easy to conduct.
The temporal resolution of an EEG is great, but the spatial resolution is poor.
What is the EEG used for? - ✔✔We can use the signals from EEGs to learn something
about cognition when people perform tasks.
How does an EEG work? - ✔✔The electrodes placed on the scalp pick up small
fluctuations of electrical signals, originating from activity of (mostly cortical) neurons.
While the raw signals recorded are very noisy and might not look like much, they are
systematically related to cognitive processes.
Who initially invented EEGs? - ✔✔Hans Berger detected the first EEG signal in 1924
with electrodes attached to the scalp of a human and reported the results in 1929.
Katelyn Whitman, All Rights Reserved © 2025 1
, Berger initially studied medicine because he was convinced that there is "psychic
energy", which might allow for telepathy.
Berger also first described the alpha rhythm - when people closed their eyes, the
electrical signal was not constant, but it varied with a characteristic frequency of 8-13
Hz.
Initially, he used two electrodes, one attached to the front of the head and one to the
rear and recorded the potential (i.e. voltage) difference between them.
Describe the neurophysiology of an EEG. - ✔✔The EEG activity does not reflect action
potentials but originates mostly from post-synaptic potentials - voltages that arise when
neurotransmitters bind to receptors on the membrane of the post-synaptic cell
This causes ion channels to open or close, leading to graded changes in the potential
across the membrane
This can be understood as a small "dipole"
Signals from single cells are not strong enough to be recorded outside of the head, but if
many neurons spatially align, then their summed potentials add up and create the
signals we can record
This pooled activity from groups of similarly oriented neurons mostly comes from large
cortical pyramid cells
Katelyn Whitman, All Rights Reserved © 2025 2
Questions and Answers 100% Pass
What is an EEG (electroencephalograph)? - ✔✔Electroencephalography (EEG) is a
method of detecting neural activity by placing electrodes on the scalp.
EEG recorded at the scalp is non-invasive - however, it is also possible to record intra-
cranial EEG by measuring activity directly at the exposed cortex.
EEG is cheap and (relatively) easy to conduct.
The temporal resolution of an EEG is great, but the spatial resolution is poor.
What is the EEG used for? - ✔✔We can use the signals from EEGs to learn something
about cognition when people perform tasks.
How does an EEG work? - ✔✔The electrodes placed on the scalp pick up small
fluctuations of electrical signals, originating from activity of (mostly cortical) neurons.
While the raw signals recorded are very noisy and might not look like much, they are
systematically related to cognitive processes.
Who initially invented EEGs? - ✔✔Hans Berger detected the first EEG signal in 1924
with electrodes attached to the scalp of a human and reported the results in 1929.
Katelyn Whitman, All Rights Reserved © 2025 1
, Berger initially studied medicine because he was convinced that there is "psychic
energy", which might allow for telepathy.
Berger also first described the alpha rhythm - when people closed their eyes, the
electrical signal was not constant, but it varied with a characteristic frequency of 8-13
Hz.
Initially, he used two electrodes, one attached to the front of the head and one to the
rear and recorded the potential (i.e. voltage) difference between them.
Describe the neurophysiology of an EEG. - ✔✔The EEG activity does not reflect action
potentials but originates mostly from post-synaptic potentials - voltages that arise when
neurotransmitters bind to receptors on the membrane of the post-synaptic cell
This causes ion channels to open or close, leading to graded changes in the potential
across the membrane
This can be understood as a small "dipole"
Signals from single cells are not strong enough to be recorded outside of the head, but if
many neurons spatially align, then their summed potentials add up and create the
signals we can record
This pooled activity from groups of similarly oriented neurons mostly comes from large
cortical pyramid cells
Katelyn Whitman, All Rights Reserved © 2025 2
