Electrodes are placed on the scalp to detect neuronal activity, directly below the area of placement, and measure changes in voltage using the same equipment as EEG.
What is shown while neuronal activity is being measured
A specific stimulus is repeatedly shown while measuring activity. It requires repeated presentation of the stimulus which leads to recurringelectricvoltage activity, which is statistically averaged together.
Why is there repeated presentation of the stimulus (ERP)
This negates the effect of extraneous activity (unrelated to the stimulus). This helps isolate the electrical activity trigger by the stimulus. This activity is eventrelatedpotential
