P300 seasonal variation

The P300 (P3) event-related brain potential (ERP) was elicited with auditory stimuli in four different groups of normal, young adult subjects (n = 20 in each group) whose ERPs were obtained at different times of the year. P3 amplitude was largest during spring and summer and smaller for the subjects who were assessed during fall and winter. P3 latency was not affected reliably by changes in the seasons. Measurement of the daily sunshine present when each subject was recorded indicated that P3 amplitude is influenced by seasonal variation in the available amount of sunshine. These findings suggest that comparison of P3 amplitude across subject groups must take seasonal differences into account.