Final answer:
Teen brains exhibit significant structural changes compared to adult brains, characterized by increased myelination, more complex folding of the cerebral cortex, and synaptic pruning, leading to enhanced efficiency and functionality.
Step-by-step explanation:
In the study of teen brains compared to adult brains, as discussed by neuroscientist Jay Giedd and illustrated by MRI images, significant developmental changes were highlighted, specifically in the context of the adolescent brain. During adolescence, there is increased myelination and more complex folding of the cerebral cortex, coupled with a process known as synaptic pruning, which eliminates unused pathways and therefore enhances the brain's efficiency and functionality.
This development is characterized by a transition from more gray matter to more white matter, as the color changes in the MRI images indicate. These biological changes affect decision-making and organizational skills, often making it seem unreasonable to expect adult levels of these skills in teenagers. The changes in the brain's white matter and synaptic pruning continue to progress until about the age of 20, suggesting that the teenage brain is still very much a work in progress.