Functional and structural neuroimaging studies by Dayan et al. indicate that adolescent brains are still undergoing reorganization in areas that deal with executive function and decision-making. Evidence of these developmental brain changes are observed in the grey matter, white matter, and other specialized regions of the brain (e.g., the limbic system).
During adolescent brain development, grey matter volume undergoes a slight increase just before puberty, but is shortly followed by a decrease during puberty. The dorsolateral prefrontal cortex and the superior temporal cortex regions of the brain are the last regions to mature, observed as a reduction in the size of these regions as the end of adolescence approaches. This decrease in observed grey matter in the frontal cortex of adolescents aged 12 to 16 can also be seen in other brain structures such as the striatum, putamen, and globus pallidus – all structures implicated in risk-taking behavior.
Dayan et al. also state that the white matter in the brain undergoes major structural reorganization during adolescence. Unlike grey matter however, white matter has been observed to increase exponentially during brain development in adolescents. Specifically, regions of the brain such as the frontal lobe, corpus callosum, and arcuate fasciculus have all been shown to have increases in white matter.
Some researchers have proposed that frequent risk-taking behavior during adolescence is due to the developmental changes in other areas of the brain such as the limbic system. They state that adolescent behavior is primarily managed by the limbic system which is functionally more maturated than the frontal regions in adolescence. As a comparison, both of these regions are underdeveloped in children whereas both of these regions are fully matured in adults.
Despite the fact that neuroimaging tests do reveal that the adolescent brain undergoes structural and functional reorganization in regions of the brain typically associated with risk-taking behavior, there is still no consistent evidence illustrating that adolescents are more prone to be involved in risky behaviors than adults. In fact, research from Reyna and Farley has shown that the ability of adolescents to make logical decisions in risky situations is equal to decision making capabilities of adults, despite the difference in brain development.