P300 event related potential in normal healthy controls of different age groups.

P300 event related potential was recorded in 115 healthy controls with a mean age of35.9±14.81 years and a male : female ratio of 72 : 43. There was significant difference in the P300 latency in < 40 years as compared to ≥ 40 years group (p< 0.001). There was no significant difference between males and females. There was a strong positive correlation between age and P300 latency (p< 0.001). The regression equation for P300 latency was Y=287.9+1.492x with an SEE of 20.2 (where Y is the P300 latency in ms, x is the age in years, SEE is the standard error of estimate). There was a negative correlation between age and P300 amplitude which was significant in ≥ 40 years age group while in > 40 years age group it was not significant.