Subject Age in P300 BCI

This paper presents a study about the amplitude, latency and distribution of P300 in twelve healthy volunteers (5 women and 7 men, aged between 19-70, with a mean of 35.5 years) that were submitted to two Novelty Oddball Paradigms. The difference between them is on stimulus modalities, which are visual and auditory. Usually, a P300-based brain computer interface has visual stimuli but we are also interested in making analogies between the two modalities. In both test modalities were presented 3 types of stimuli: a `standard' stimulus, a `target' stimulus, to which the subject must respond, and a `novel' stimulus. Most of the subjects were students and are naive to the purposes of the experiment. The subject is not warned about the `novel'. We recorded scalp potentials from 18 channels distributed in a standard configuration 10-20 system. Target P300 had more relevance than novel P300 for a BCI application. Results show relevant differences in amplitude and latency in P300 signal for different ages. The older subjects (>51 years) show smaller P300 amplitudes than younger. Therefore, the subject age must be taken into account when a P300 BCI application is implemented