Assessment | Biopsychology | Comparative | Cognitive | Developmental | Language | Individual differences | Personality | Philosophy | Social | Methods | Statistics | Clinical | Educational | Industrial | Professional items | World psychology | Biological: Behavioural genetics · Evolutionary psychology · Neuroanatomy · Neurochemistry · Neuroendocrinology · Neuroscience · Psychoneuroimmunology · Physiological Psychology · Psychopharmacology (Index, Outline) The P300 (P3) wave is an event related potential (ERP) elicited by infrequent, task-relevant stimuli.
found that ERP responses to visual stimuli differed depending on whether the stimuli had meaning or not.
They showed subjects two kinds of visual stimuli: numbers and flashes of light.
In a second experiment, they presented two cue types.
For one cue there was a 2 in 3 chance that the following stimulus would be a click and a 1 in 3 chance that the following stimulus would be a flash.
Chapman and Bragdon speculated that this differential response to the numbers, which came to be known as the P300 response, resulted from the fact that the numbers were meaningful to the participants, based on the task that they were asked to perform.
In 1965, Sutton and colleagues published results from two experiments that further explored this late positivity.Since the initial discovery of this ERP component, research has shown that the P300 is not a unitary phenomenon.Rather, we can distinguish between two subcomponents of the P300: the novelty P3, or P3a, and the classic P3, or P3b.The second cue type had probabilities that were the reverse of the first.They found that the amplitude of the positive complex was larger in response to the less probable stimuli, or the one that only had a 1 in 3 chance of appearing.They observed a positivity around 300 ms after the second click occurred or would have occurred in the case of the single click.