The recognition potential contrasted with the P300.

An electrical response of the brain to recognizable images was described. The response (referred to as the "recognition potential") occurred for words, pictures, and faces, but not for non-meaningful control images. It was best recorded from the occipital area. The peak latency was 200-250 ms. It differed from the P300 response in latency, topography, and sensitivity to probability of occurrence. Its amplitude depended on the site of recording and the visual field stimulated. Degradation of the images caused equal increases in reaction time (RT) and recognition potential latency. The results contradicted the proposal that the latency of the P300 can be used as a measure of the timing of stimulus evaluation processes.