INDIVIDUAL-DIFFERENCES IN P300 AMPLITUDE - A GENETIC-STUDY IN ADOLESCENT TWINS

Using quantitative genetic research designs, we decomposed phenotypic variance in P300 parameters into genetic and environmental components. The twin method was used to carry out this decomposition. Event relat ed potentials (ERPs) were measured during a visual oddball paradigm in a sample of 213 adolescent twin pairs. The presence of male and femal e same-sex and opposite-sex twins in the sample enabled us to study se x differences in the contributions; of genetic and environmental effec ts to P300 parameters. For targets and nontargets, half of the varianc e in the P300 amplitude is attributable to factors shared by the famil y members. However, it remains unclear whether this resemblance is att ributable to shared environmental or genetic influences. The same fact ors (genetic or shared environmental) were found to contribute to the individual differences in males and females. The contributions do, how ever, differ across gender. Multivariate genetic analyses investigated the covariance among various brain areas to determine whether the cov ariance between two or more leads is attributable to the same genetic and/or the same environmental factors. The covariance of the P300 ampl itude measured at different locations was attributable both to unshare d environmental. and to shared factors. Again it was not possible to s how that the shared factors where either genetic or shared environment al. (C) 1998 Elsevier Science B.V. All rights reserved.