Tamm, Menon, & Reiss, 2002). If P300 amplitude reflects genetic influences on the development of frontally influenced cognitive processes, a more restrictive limit on the degrees of freedom available for neuronal and synaptic pruning in vulnerable children could limit the rate of decrease possible for P300 amplitude over adolescence and into early adulthood. The limited number of relevant neurons activated could thus be reflected by both the lower intercept (fewer neurons) and the smaller slope (fewer cells to lose) seen in the young men at risk for externalizing problems reported here.
