Although researchers continue to study patterns of grey matter development in adolescence, increased attention is now being given to changes in white matter during this period, in part stimulated by the growing use of DTI to study changes in structural connectivity. Indeed, whereas synaptic pruning in the frontal lobe was the main focus of attention in previous research on structural aspects of brain development in adolescence, white matter development has clearly stolen some of the scientific limelight. It is now clear that adolescence is a time of dramatic changes in fiber tracts that link different brain regions and structures (Schmithorst & Yuan, this issue). This increase in structural connectivity is, not surprisingly, paralleled by increases in functional connectivity, which has significant implications for our understanding of changes in adolescent behavior, especially with regard to cognitive control (Luna et al., this issue). An important lesson for behavioral scientists about brain development in adolescence therefore is that it is not, as the popular media would suggest, all about synaptic pruning in the frontal lobe.
