Abstract
We investigated which factors affected the appearance of the P3 event-related potential (ERP) component in an auditory passive oddball paradigm. P3 waves from the two passive procedures (the simple ignore condition and the condition with a distracting task) were compared P3 wave from the active discrimination task condition. In Experiment 1, the sequence of stimuli consisted of infrequent 3000 Hz (p=.20) and 500 Hz tone bursts (p=.80). In Experiment 2, the 3000 Hz tone burst was replaced by a click.
The distinct P3 appeared in the ignore condition in Experiment 2, that had similar scalp distribution and latency to those from the active condition. In the other passive conditions in Experiments 1 and 2, P3 did not appear. These findings suggest that some qualitative differences between frequent and infrequent tones could cause the appearance of P3 in the passive oddball paradigm. The clinical applications of passive P3 for the subject populations who are unable to reach the required performances, are discussed.
