Why does an EEG signal need to be averaged over many trials to generate an ERP?
A) EEG has a poor spatial resolution.
B) EEG has a low signal:noise ratio.
C) The scalp potentials from a single EEG trial are too weak to measure.
D) To ensure that the ERP is reliable over time

Question

Quizplus · Accepted Answer

EEG signals have a low signal:noise ratio, meaning that the electrical activity from the brain is very small compared to other sources of electrical activity in the environment (such as muscle movements or electrical interference). By averaging many trials together, the signal from the brain is "boosted" while the noise from other sources cancels out, resulting in a clearer and more reliable ERP.

Why Does an EEG Signal Need to Be Averaged Over