1. ADOLESCENT BRAIN DEVELOPMENT
John Sexton
Westchester Library System
4/7/09

5. Phineas Gage 1848

9. The natural development of different brain structures is an important source of behavior change in adolescents.”
David Allen Walsh, Why Do They Act That Way? 2004

10. The Brain Stem Unconscious physiological functioning-
breathing, heart beat
Involuntary responses- reflexes, moving your hand away from a hot stove

11. The Limbic Brain The Amygdala The Hippocampus The Ventral Striatal
The Hypothalamus

12. The Amygdala
Plays a central role in the processing of emotions- the development in adolescence is characterized by emotional intensity and volatility. Decision making is based on emotions rather than reasoned judgment.

13. The Hippocampus
The hippocampus plays a major role in encoding memories
Increases in volume up to age 18
Is larger in females than males

14. The Hypothalamus
The control center of the endocrine system which regulates hormones

15. The Role of Hormones
Melatonin levels change which entices a change in sleep patterns.
Leptin influences fat storage. In boys this influence is suppressed by testosterone which brings about a dramatic increase in muscle mass.
Testosterone stimulates the amygdala. Levels in the body are twenty times higher for males than females.

16. The Role of Hormones
Neurotransmitters have a large effect on mood. They include norepinephrine, dopamine, and serotonin.
Estrogen and progesterone have a powerful influence on neurotransmitters which can cause sudden and dramatic mood swings.

17. The Cortex Conscious thought and reason The Prefrontal Cortex
The Right and Left Hemispheres
The Corpus Callosum- connecting the two hemispheres

18. The Prefrontal Cortex The brain’s executive or CEO
Responsible for planning ahead, considering consequences and managing emotional impulses.

19. Blossoming and Pruning
Blossoming-The brain develops in busts not in an even uniform way
Pruning- some of our mental abilities develop not from adding of new synapses but from eliminating those that are weak and underused.

20. Myelination
Myelin acts as insulation for the neuron’s axons. Axons that are not insulated with myelin are more prone to interference which causes messages to travel more slowly. An electrical charge that travels on a myelinated neuron travels one hundred times faster than on a non-myelinated neuron.

21. What can we do to help teens achieve positive brain development?
Create opportunities to reinforce the use it or lose it principal.
Create risk taking opportunities that have positive outcomes.
Talk with teens about alternative possible decisions and their potential outcomes. It is important to listen to their point of view.

22. EMOTIONS
Adolescents use the Amgydala (fight or flight response) rather than the Frontal Cortex (used by older adults) to read emotions
Deborah Yurgelun Todd McLean Hospital Belmont, Mass (2004)

23. THE ADOLESCENT BRAIN Frontal Lobe Immaturity Could Translate Into:
1. Poor judgment and difficulty thinking through consequences of behavior
2. Increased risk-taking; inappropriate actions not as inhibited as in adults
3. Impulsive and emotional responses rather than logical and practical ones
4. Miscommunication with peers and adults—they miss subtle social cues, misinterpret expectations, and misread facial expressions.
Phineas Gage 1848

24. THE ADOLESCENT BRAIN AND SLEEP
Based on the Research of Dr. Mary Carskadon, Brown University Sleep Laboratory
The average college student needs and young adults require 6-8 hours of sleep per night. Most get 5 or less.
During adolescence there is a shift in their circadian rhythm or biological clock
Melatonin levels peak around 11 p.m. to midnight.
Ideal wake up time for an adolescent would be around 9 or 10 a.m.

25. MORE ON SLEEP
*Purpose of sleep appears at least in part to be to review/rehearse things learned during the day.
*Getting a good night of sleep after an important learning experience is critical to retention of material and learning (See Time “The New Science of Sleep” Dec. 2004)
*Carskadon (Brown) and Wolfson (Holy Cross) sleep study (2000)
*Ron Dahl (U of Pittsburg) and Eve Van Cauter (U of Chicago) study (2001)
Sleep deprived youth experienced….
--elevated levels of the stress hormone cortisol (high bp)
--impaired ability to process glucose (obesity and type 2 diabetes)
--emotions less controlled and more exaggerated
--increased depression and anxiety

26. Dopamine—brain chemical that creates a sense of well being
WHY DO TEENS ENGAGE IN RISKY BEHAVIORS?
Dopamine—brain chemical that creates a sense of well being
During adolescence dopamine levels decrease in the nucleus accumbens (smaller subcortical area involved in
pleasure response).”Adolescents have a built in urge to live on the edge,to seek thrills, to do things that will enhance chances of survival within the peer group.” Linda Spear—SUNY-Binghamton (2003)
High levels of stress reduces dopamine levels.
Addictive drugs increase dopamine levels and can damage the nucleus accumbens

27. Dopamine and Risk Taking Behavior
The neurotransmitter involved in pleasure in the brain is dopamine. Dopamine is associated with both motivation and salience (recognizing when something is important). Reporting in Science magazine (2003)- dopamine neurons are most active when the prospect of a reward is less certain. Higher levels of uncertainty may be necessary to prompt activity of dopamine receptors in teens- which results in engaging in risk taking activities.

28. Teen Brains in the Library
Consider your facial expressions
Provide space where they can socialize, learn, play, read, engage and experiment.
Provide structure and support.
Understand they are under construction
Remember, Search strategies are like algebra & logic, incomprehensible to the immature brain. Repetition is imperative.