High Quality Content by WIKIPEDIA articles! The P3a, or novelty P3, is a component of time-locked (EEG) signals known as event-related potentials (ERP). The P3a is a positive-going scalp-recorded brain potential that has a maximum amplitude over frontal/central electrode sites with a peak latency falling in the range of 250-280 ms. The P3a has been associated with brain activity related to the engagement of attention (especially orienting and involuntary shifts to changes in the environment) and the processing of novelty.