How the Adolescent Brain Challenges the Adult Brain
by Dr. Kathie F. Nunley
What makes the adolescent brain so challenging to the adult brain? Anyone who has ever tried to parent, teach or mentor the adolescent brain knows it can create some frustrating moments. A lot of this frustration can be blamed on some of the biology unique to the adolescent brain.
In any aged brain, the region responsible for basic survival needs (eat, flight/fight, sex) are handled by a region known as the hypothalamus. For obvious reason, the hypothalamus is powerful, influential and ready to function right from birth. Biologically speaking, if this area was not given top priority, the animal may not survive for long.
One of the frustrations with adolescents is due to the fact that hormones, environment, and learning, make this survival region of the brain a "hot area" in adolescent brains.
In addition, the basic survival drives of the hypothalamus don't always agree with the social structure, morals and safety of society. For the more "civilized" human behaviors we need to involve higher regions of the brain. Higher brain regions, in the cortex, can over-ride the hypothalamus. Although these regions are not given biological priority, they are the "logical" parts of the brain and are responsible for deciding when basic hypothalamus drives may not be in our best long-term interest.
A region called the prefrontal cortex plays the role of arbitrator in making these critical decisions. It quickly sizes up the situation and makes a determination which then drives our behavior. It is the prefrontal cortex then that tells us when to act on our anger, or curtail it, eat that second piece of dessert, or go without, seek immediate gratification or hold off for the long term.
Unfortunately some people have a poorly developed or poorly functioning prefrontal cortex. These people have a hard time controlling impulsive behaviors. Head trauma, alcohol and drug abuse as well as possible genetic predispositions can all lead to a dysfunctional prefrontal cortex. Maturity also plays a big role as this area takes about 20 years to fully develop. Hence, adolescents may have problems quickly sizing up risks and making good ong-term decisions.
Other biological factors make adolescent brains even more hypothalamus driven. Children learn what to do with anger by watching other people in their sphere of influence and what they do when they are angry. Peer-influence peaks during the teen-age years which means that key role models for an adolescent are other adolescents.
The hormone, oxytocin, found in the brain during romantic relationships, tends to settle and stimulate the hypothalamus during the beginning stages of the relationship. Anyone working with adolescents knows that they are always in the midst of "new love", which only further hampers logical decision making.
So adolescents appear to have at least 3 strikes against them when it comes to using logic to weigh the risks in dangerous or sometimes even everyday types of decisions. The more primitive regions of their brains are strong and tend to drive behaviors. The immature region responsible for the logic of long-term benefits does not always override the impulsive, survival-oriented hypothalamus. Add any additional trauma to the mix such as abusive households or drug and alcohol use and the issue becomes even more severe.
The biology of brain shows that adolescents still need strong adult guidance and help with decision making throughout the teen-age years . Time and good role models will fortunately allow the brain to eventually mature to match the body.
Source: http://www.help4teachers.com/prefrontalcortex.htm
Brain Biology:
It's basic gardening.
By Kathie F Nunley
As you read the words on this page, you are utilizing thousands of the 100 billion (more or less) nerve cells that make up your brain. The electrical firings and chemical messages running between these cells, called neurons, are what produce our thoughts, feelings and interactions with the world around us.
One hundred billion neurons may seem like a lot of nerve cells, but is actually only about 20% of the number we originally start with. The number of nerve cells in our brain peaks prenatally and then they start to prune themselves out, one by one, through childhood. By the time we enter adolescence, our brain has chosen the final select neurons it will keep throughout our adult life. The decision is based on which cells we use and which we do not. The cells we do not use are pruned away leaving more room to add branches, or dendrites, to the nerve cells that we do use. New branches are added as the brain receives and processes any new information.
How does the brain actually "prune" the garden? The answer lies in a number of chemicals and their actions and reactions. The chief pruner is probably an enzyme named Calpain. Calpain has the ability to self-destruct a cell. Technically this is known as autolysis ("auto" meaning self, and "lysis" meaning to destroy).
Calpain is produced in the nerve cells when there is a heavy calcium ion concentration in their surrounding environment. Reduced blood flow can cause this high calcium ion build up between and within cells (for you biology enthusiasts, the calcium comes from the mitochondria and the ER as well as an influx from outside the cell). In other words, high activity in a brain region calls for heavy blood flow to service the cells, low activity requires little blood flow. Therefore, the less-used areas, with their limited blood flow activity, tend to build up calcium ions. This build-up triggers the secretion of the enzyme Calpain, which causes the nerve cell to self -destruct.
New growth, on the other hand, comes in the dendrite development, or branching of well-used neurons. This branching is caused from chemicals known as Neurotrophins. Neurotrophins are a group of proteins which are responsible for the growth and development of neurons. As you may suspect, we use a lot of neurotrophins during childhood as the brain has massive growth and development. But we continue to use neurotrophins all of our lives, especially in the hippocampus area, the brain region responsible for new learning and new memory formation.
There are many neurotrophins at work in the brain. The first one discovered is known as NGF (nerve growth factor). Others, discovered since, have equally self-explanatory names as brain derived neurotrophic factor (bFGF), and glial cell-line derived neurotropic factor (GDNF). These neurotrophins work by attaching themselves to receptor sites on nerve cells and causing the cell membrane to change shape, grow and branch.
Because most growth hormones throughout the body are especially active during sleep, it is thought that the majority of neurotrophic work is also done during sleep, especially the non-REM cycles of sleep. The work of Marcos Frank and Michael Stryker, at UC San Francisco, caught the education world by surprise in 2001 with their startling research showing the tremendous amount of branching and subsequent learning that took place during sleep. While most of the science community historically considered that the REM, or dreaming cycle of sleep was the time when most wiring took place, Stryker's work and the research following that study continue to show that it is actually the non-REM cycles that help hard wire in the information learned the previous day.
From a practical standpoint, sleep research continues to show the importance of sleep to the learning brain. Students MUST get sufficient sleep following the learning of new information if we want that information stored in a long-term, complex network of neuron branches.
The research on brain wiring and the biology behind it continues to be a fascinating topic. It gives hope to people with stroke damage, Alzheimer's and other neurological problems, as well as providing a better understanding for those of us who parent and teach young brains.
Remember to learn something new today. . . then sleep on it.
Source: http://help4teachers.com/gardening.htm
Stress- a land mine for the brain
by Dr. Kathie F. Nunley
Stress is more than just uncomfortable, it's dangerous to the mind and body. In addition to increasing health problems, chronic stress causes problems with our memory systems, blood pressure, problem solving skills, and thought processes in that decision-making region of the brain known as the prefrontal cortex.
Although some teachers feel stress is an inevitable part of the education process, research shows it can actually undermine the learning process. Stress in the classroom or elsewhere, releases a chemical called TMT* into the brain. TMT disrupts working memory and reduces a person's desire to explore new ideas and creatively solve problems. While students under stress will work "harder", the quality of the work decreases. The higher the stress, the worse the results. Short term memory is crippled, the student has a difficult time retrieving previous information from memory and decision making ability decreases.
Obviously, we wouldn't want to remove all stress from life, as a small amount can help keep arousal levels high enough to complete a task. But large amounts, particularly when the stress causes accompanying feelings of fear and anxiety, are dangerous and work against the learning process.
Be careful in the classroom. A little excitement and encouragement built on a strong foundation of trust and care can help build enthusiasm for doing well. An environment perceived as intimidating, frightening and overwhelming can shut the learning process down.
Recently while visiting a graphic design class, I saw a poster on the door to the special effects lab that read "don't make a garlic sandwich". I love that thought. It helps remind us that some things are only good in very small quantities.
Source: http://help4teachers.com/stress.htm
Kathie F. Nunley is an educational psychologist, author, researcher and speaker living in southern New Hampshire. Developer of the Layered Curriculumâ„¢ method of instruction, Dr. Nunley has authored several books and articles on teaching in mixed-ability classrooms and other problems facing today's teachers. Full references and additional teaching and parental tips are available at: http://Help4Teachers.com
“Transitioning Students' Journey, Building Habits for Success”
“Respecting Differences; Enhancing Achievement; Safe Environment; Personal Growth; Excellence; Communication; The Whole Individual”