Mysteries of the Teenage Brain Revealed

Posted on January 10, 2014. Category: Children's Clinic Blog

While for many years differences in teen behaviors (from adults and children) were attributed to the influx of hormones or developmental changes they were experiencing, scientists are now realizing that in fact some of those differences are occurring because of what is happening in the brain.

Here is an overview of some of what they’ve found so far:

  • The part of the brain called “prefrontal cortex” (located behind the forehead) is the part of the  brain responsible for planning, decision making, paying attention, impulsivity, motivation, and working memory (among other things).   In teens, this is the last part of the brain to mature, meaning that for a large portion of adolescence this area is “under construction”.   It doesn’t mean it doesn’t work at all, but, as with any construction site, you can expect delays and other evidence that it is not “finished” yet.   Scientists say that this part of the brain does not fully develop until age 25.
  • The rest of the brain is busy being re-wired: new neural pathways are being laid down (basically, the “roads” of the brain that carry information from one part of the brain to another), old ones are being pruned (or not paved and saved), as the entire brain is re-working its connections.   This can result in moments of fuzzy logic and sometimes in the teen brain’s inability to, literally, ‘get from here to there’, in terms of making decisions or connections between two different things.
  • The Amygdala is the emotional seat of the brain, and it grows very quickly and early on during adolescence. Unfortunately, even as the ability to feel things intensely is going into overdrive, the parts of the brain responsible for the cognitive control system (basically, the parts that “think”) lag behind, as noted above.  Scientists call this “a temporal gap”.
  • When teens were shown a picture of a person who was scared, they tended to label the person’s expression as one of shock, surprise, or anger.  When adults were shown that same picture, they were more likely to accurately describe the expression as fearful.  More importantly however, this study was done while those teens and adults were inside an MRI machine which showed that different areas of the brain were “lighting up” (and therefore being used) in the teen brains vs. the adult brains.  In Teens it was the Amygdala, the seat of emotions (or “reactions”), which was being used, while adults mainly used their Frontal Cortex (seat of reason and logic) to determine what they were seeing.  This leads researchers to believe teens may not always be able to judge emotional situations accurately, as they tend to “react” rather than “reason”.

Understanding that teens really are experiencing the world differently than adults do is important to keep in mind as we attempt to guide young people through the often choppy waters of adolescence.  If your teen is also experiencing mental health issues, has had trauma, or is having significant behavioral problems that are falling far outside the range of what normal brain development might explain, it’s important that you have your teen evaluated so that the need for treatment is determined as soon as possible.