title: Sex differences in the human group mean SEP.
abstract: The following results were obtained with SEPs recorded from strictly age-matched normal human subjects, 100 males and 100 females, 22.29 +/- 1.90 years. (1) The sex factor on the wave form of SEP was confirmed highly significant by MANOVA. (2) It was confirmed that the group mean SEP of each sex each converges to a given wave form which significantly differed from each other. (3) The differences in the wave form of the group mean SEP between sexes were established. The group mean SEP for females consisted of the 12 components, N1, P1, N2, P2, N3, P3, N4, P4, N5, P5, N6 and P6, and was approximately tetraphasic within 500 msec in latency, while that for males consisted of the same components except for N4 and P4. The baseline amplitude of the wave form of the group mean SEP, smaller in males than in females, differed significantly between sexes, corresponding to the most remarkable difference in its wave form, in the descending slope from the highest positive peak P2 to the deep negative trough N6, where there was a high convex arch with P4 (80 msec) in females, a low hollow slope without the peak in males. The latencies of the components tended to be longer in males than in females. (4) With scaled SEPs, which were converted from SEPs by amplitude scaling, results were similar to those with SEPs, and the sex difference in the scaled group mean SEP was also verified to be significant. These results indicate the further possibility of data reduction by amplitude scaling.
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D005073:Evoked Potentials, Somatosensory; D005260:Female; D006801:Humans; D008297:Male; D012737:Sex Factors