Mental Workload and P300 Component of Event-Related Brain Potentials in a Visual Monitoring Task

The attributes of event-related brain potentials (ERPs) when combined with the information gained from the study of apparent human behavior, can provide valuable information about central nervous system processes. This study illustrates the manner in which these attributes, specifically P300 amplitude, can be used to study human information processing. This research investigated the effects of a systematic increase in mental workload, and the position of the stimulus on the P300 amplitude. The task chosen was a visual monitoring task with four levels of increased task difficulty. A slight increase in the P300 amplitude was observed from level 1 to level 2. At level 3, a significant increase in the amplitude of P300 component was observed from level 2. At level four, no major increase in the P300 amplitude was observed from level 3. At any task difficulty level, the P300 amplitudes were not affected by the position of the monitored cell. Infrequent large changes in the readout value of the monitored cells elicited larger P300 amplitudes than frequent small changes.