Thursday, September 22, 2005

Teens -- It isn't Hormones, It's Brain Reconstruction

Ok, this is sort of cool and helps to explain a lot of things. I like to read about how the brain works and someone recently handed me an article about teen brains. It reiterated some information that I had heard on a science program on CBC. Basically it says that there is a period of time in adolescence when the brain undergoes massive renovations. So it isn't just hormonal surges causing your teen to be moody, emotional, irrational and hard to manage.

It used to be thought that when the brain stopped its massive growth by age 2, it was pretty well done for the rest of life. However, recent research in Canada and the US is revealing that previous notions of the adolescent brain are wrong. Adolescent brains go through a biological remodelling as part of human development that is as profound as that which babies experience. Virtually every part of the teenage brain is under reconstruction. Nodes, lobes, neurons, synapses, long strings of axons, which are the pathways for electrical signals from one part of the brain to the other, dendrites, etc., all feel the effects of this change.

Basically, what is happening is that the body is physically restructuring the brain so that it can operate as an adult. During this processthe higher reasoning processes of the front brain are somewhat interrupted or short circuited, and the amygdala, that part of the brain responsible for emotions, tends to be where they operate from.

Dr. Jay Giedd of the US National Institutes of Health was looking at the results of teenage brain scans and realized that the brains he was looking at were undergoing major changes. The grey matter was thickening and over-producing cells and then dramatically thinning down -- something that was previously thought to be over by kindergarten.

Dr. Giedd's work combined with that of Tomaz Paus of Montreal Neurological Institute and the University of Chicago's Peter Huttenlocher has found that teens experience literal short circuits in their neural wiring to their memory function and have difficulty interpreting facial expressions, instructions, and jokes during this time. This is because they are using the brain's primal fight or flight center to operate from rather than the rational center for decoding social signals, with resulting misinterpretations. Brain scans of teens who were shown a picture of a man whose face was contorted with fear showed that the amygdala, rather than the prefrontal cortex (the center for adult rational judgement) was lit up during the "reasoning" process.

Research is also suggesting that the connections between the right and left hemisphere of teens' brains is incomplete which affects their abilities to link speech and written language to thought. Synaptic gaps in the brains of younger teens makes abstract thinking, such as algebraic equations, puns, and the "grey" areas of life difficult for them to grasp.

Brain chemistry is also responsible for their desire to stay up late and sleep in late. For whatever reason, a teen usually doesn't start producing melatonin until around 10:30 at night -- just as their parents are starting to crash. They also need about 10 hours of sleep, which is two more hours than their parents need. Sleep deprivation can't be doing their brain power any good if we insist of seeing them bright and early every morning.

Think of the prefrontal cortex as the software responsible for risk assessment and impulse control. It is the last region of the brain to reach full development, and doesn't do so until their owners are past 20. Now do you know why your teens take risks and do things that make you go grey?

The disorganization of their rooms, lockers, and backpacks is a mirror of the brain disorganization in their heads. At the same time that some areas are growing rapidly, other areas are being pruned. Here is where the "use it or lose it" effect really takes hold. Teens who are allowed to become couchpotatoes with well developed video game abilities are going to lose parts of the brain that could be used for acquiring knowledge or understanding. It is therefore important to keep teens stimulated with music lessons, sports, learning languages, and other activities that will stimulate the brain and keep it making neural connections. In other words, stimulate them with the same dedication you showed in stimulating your babies and tots to maximize brain power.

I've already requested the book from my local library that discusses the research in this area. If you want to read it too, get ahold of The Primal Teen: What the New Discoveries About the Teenage Brain Tell Us About Our Kids by Barbara Strauch.

3 comments:

brother john said...

"For whatever reason, a teen usually doesn't start producing melatonin until around 10:30 at night -- just as their parents are starting to crash. They also need about 10 hours of sleep, which is two more hours than their parents need. Sleep deprivation can't be doing their brain power any good if we insist of seeing them bright and early every morning...
The disorganization of their rooms, lockers, and backpacks is a mirror of the brain disorganization in their heads."

Aha! Well, you see, there's my problem. I apparently haven't finished adolescence yet.

Samantha said...

I found this fascinating, Cheryl!

Stacy said...

Couldn't someone please use this research to keep kids from driving until they're at least 20 years old?! (Ha)

This information linked with what we know about the importance of good nutrition (and the nutrition MOST teens are NOT getting) makes me very nervous to be on the street with teen drivers (that and their cell phones!)