View all slides | Contents of this slide

Lecture Notes

The other important evoked potential is the P300; and this is in the positive voltage direction, which occurs at about 300 to 500 milliseconds after the stimulus is presented. And this is roughly analogous to perception of the stimulus and when attention is given to the stimulus; and of course, in the second half of this course, we do look more closely at sensation and perception and how those work. So this is sort of a flavor of things to come, but what we find within this evoked potential is that the size of the P300 is usually larger when presented with a surprising stimulus or if someone calls your name. If a surprising stimulus does not evoke a large P300, this could be indicative of brain damage; so this is a way that neuroscientists, cognitive psychologists, might also be able to understand not only brain function but brain dysfunction.