Abstract
P300, which is one of the event related potential (EPR), is induced by an oddball task.P300 is a positive electric potential change which is elicited around 300ms after the stimulus. Various factors affect P300 such as the kind of targets, difficulty of tasks, stimulation interval, ratio of the low-frequency stimulation, age of users and so on. Previous studies reported that the peak latency of P300 in healthy adults becomes longer with the aging. However, the peak latency of the P300 also depends on the difficulty of tasks. Thus we studied the relation between the difficulty of tasks and the peak latency of P300 by two types of experiments. One was two visual sight stimulation tasks (large/small square and large/small circle), and the other was two types of three visual sight stimulation tasks (large/small square, small circle and large/small circle, small square). These experiments showed that the peak latencies of P300 were different between the tasks. We focused on the difference in the processing of brain activity based on a current source estimate using MEG (MagnEtoencephaloGraphy), and we discussed the difference of the peak latency of P300 between the tasks.
