[The visual P300 (pattern flash P300) in the physiologic aging process]

Abstract

For studying the relationship between the PFP300 (Pattern Flash elicited P300) and age we investigated 73 healthy subjects - 34 males, 39 females - between 18 and 60 years of age by presenting randomly two different checkerboards A (16 X 16 caskets visual angle = 50') and B (64 X 64 caskets visual angle = 12.5') to them (A:B = 80:20). The subjects' task was to keep a running count in their heads of the infrequent B-stimuli only. The resulting A- and B-responses were derived from Oz to Fz (Cz was ground). The results were as follows: 1. Comparing the PFP300-parameters between age group I (N = 46, 18-30 years) and age group II (N = 27, 31-60 years) we found that in the elder group both the N250-latencies (in B-potentials) and the PFP300a-latencies (in A-potentials) are significantly prolonged (p less than or equal to 0.01). The ascending PFP300a-amplitudes, however, remain (still?) unchanged. 2. Regression analyses between the PFP300-parameters and age for the total group revealed significant relationships for both the N250- (r = 0.35, P less than or equal to 0.01) and PFP300a-latencies (r = 0.78, P less than or equal to 0.01) and PFP300a-latencies (r = 0.78, P less than or equal to 0.01). In contrast to this, we could only find a zero correlation for the ascending PFP300a-amplitudes. 3. The coefficient of the regression line was 0.71 ms/year for the N250-latency and 1.09 ms/year for the PFP300a-latency. These findings indicate that one has to build age-matched control groups for applying PFP300 to pathophysiological processes.