Power spectral analysis of photic driving elicited by flickering dot pattern and red flicker stimuli in adult psychiatric outpatients--with special reference to age and gender.

Power spectrum of photic driving elicited by 5/sec flickering dot pattern (FDP) and 5/sec red flicker (RF) stimuli was investigated in 137 psychiatric outpatients. They consisted of 61 adults (33 males and 28 females) from 20 to 44 years of age, 55 preseniles (25 males and 30 females) from 45 to 64 years and 21 seniles (9 males and 12 females) over 65 years of age. Powers of 5 and 10/sec photic driving elicited by FDP and RF stimuli were greater than those of the other higher harmonics and increased significantly with age. When such a finding was compared in relation to gender, significant increase of power with age was found for 5 and 10/sec photic driving elicited by both stimuli in females, whereas it was found only for 5/sec photic driving elicited by RF stimulation in males. Our findings suggest that the visual system of older female patients is very responsive not only to patterned stimuli but also to red flicker stimulation.