ERP Flashcards
What does ERP stand for?
Event related potential.
What is an ERP?
A signal seen on an EEG as a rapid single potential change as a response to a sensory, cognitive or motor event.
What is the P300 signal?
An ERP where the signal’s peak comes an average of 300 milliseconds after the stimulus.
How does an ERP differ from rhythmic waves, e.g. alpha waves?
Rhythmic waves reflect a longer term state that the brain is experiencing.
Which brain region is the P300 signal thought to come from?
Parietal lobe.
What is hemi-neglect?
People with damage to the right parietal hemisphere can often have difficulty acknowledging the existence of the left side of the world.
What is the role of the parietal lobe in generating the P300 signal?
It helps assess unexpected stimuli and generates a neural response.
What is an oddball task?
A participant will hear a repeated, regular presentation of tones of a particular frequency, but 10% of the time it will instead be a higher pitched tone to elicit a P300 signal.
Why is an oddball task also called the “Consciousness Detector”?
If you perform the oddball task on an individual in a coma and you observe a variant of the P300 signal, it is a strong indicator that they may be able to be brought out of the coma.
What is the primary purpose of averaging multiple trials in the oddball task experiment?
To enhance the visibility of the P300 signal by reducing random noise.
What does TTL stand for?
Transistor-Transistor Logic.
What is a TTL?
A type of digital circuit that uses bipolar junction transistors (BJTs) to process signals.
How does the digital input work?
It detects whether the button is pressed or not based on the TTL voltage levels, allowing the precise timing the button was pressed to be recorded.
What is the 10-20 EEG system?
A standardised way to place electrodes on the scalp for EEG.
Why is it called the 10-20 EEG system?
The electrodes are placed 10-20% apart based on head size.
Why do we have standardised electrode placement for EEG?
To ensure that EEG data is collected consistently across different studies and experiments.
What is the nasion?
The point between the forehead and the nose.
What is the inion?
The bump at the lower back of the skull.
What is the left preauricular point?
The front of the left ear.
What is the right preauricular point?
The front of the right ear.
Which numbers indicate left hemisphere placement?
Odd numbers.
Which numbers indicate right hemisphere placement?
Even numbers.
What does Z (zero) mean?
The electrode is in the midline of the head.
