Transcript Slide 1

“My brain made me do it!”
What Makes Teens Tick
Pair and Share
Partner Up and Pair and Share your
responses by completing the following
prompts:
1. Re read your 8pts and personal connections
from the article. Circle the one you believe is
the most important in understanding the
Biology of TEEN behavior.
2. Read pg. 31 of the article “7 Rules for
Parents” Discuss which “Rule” you think is
the most important and why?
3. What from the article do you have more
questions about? Come up with 1 Question
Adolescence = Storm and Stress
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Adolescence can be a dangerous time. Some of the most life-threatening risks that
people take — drunk driving, binge drinking, smoking, having unprotected sex
— are especially common during the teenage years, as illustrated by the following
statistics:
 Both males and females between the ages of 16 and 20 are at least twice as
likely to be in car accidents than drivers between the ages of 20 and 50 are.
Auto accidents are the leading cause of death among 15- to 20-year-olds, and
31 percent of young drivers killed in motor vehicle crashes in 2003 had been
drinking.
 Three million adolescents contract sexually transmitted diseases every year.
 More than half of all new cases of HIV infection occur in people younger than
25, making AIDS the seventh leading cause of death among 13- to 24-yearolds. Two young people in the U.S. are infected with HIV every hour.
 Forty percent of adult alcoholics report having their first drinking problems
between the ages of 15 and 19.
 Evidence of pathological or problem gambling is found in 10 to 14 percent of
adolescents, and gambling typically begins by age 12 (Reyna, 2006, para 1) .
 Major mental illnesses, such as schizophrenia and bipolar disorder, typically
begin in adolescence and contribute to the high rate of teen suicide (Wallis,
2004, para 4).
Reported Drug and Alcohol Use by
High School Seniors, 2006
(US Dept of Justice)
Drugs
Use within the
last 12 months
Use within the
last 30 days
Alcohol
66.5%
45.3%
Marijuana
31.5
18.3
Other Opiates
9.0
3.8
Stimulants
8.1
3.7
Sedatives
6.6
3.0
Tranquilizers
6.6
2.7
Cocaine
5.7
2.5
Hallucinogens
4.9
1.5
Inhalants
4.5
1.5
Steroids
1.8
1.1
Heroin
0.8
0.4
Adolescence = Storm and Stress
59 Lives Lost: Teen drivers were involved in at least 49
fatal crashes in 2006 in the Chicago-land area (Chicago
Tribune, 2007)
Research Methods/Tools
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A critical tool in studying the
adolescent brain is functional
magnetic resonance imaging (fMRI).
While ordinary MRI reveals brain
structure, fMRI actually shows brain
activity while subjects are doing
assigned tasks (Wallis, 2004, para18)
Linda Spear, PhD, distinguished
professor of psychology at the State
University of New York at
Binghamton, explains, “As helpful as
imaging technologies are for allowing
a noninvasive glimpse into healthy,
living tissues, the old standby animal research -continues to provide
important insights. There is a lot you
can do with fMRI and MRI, but with
animal studies, you can start trying to
dissect down and ask about causal
changes” (Packard, 2007, p 22).
Biological Differences: Pruning and
Proliferation
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We are born equipped with most of the
neurons our brain will ever have.
The brain grows very little over the course
of childhood. By the time a child is 6, it is
90% to 95% of its adult size (Wallis, 2004,
para 10).
There is a second wave of proliferation
and pruning that occurs later in childhood
and the final, critical part of this second
wave, affecting some of our highest
mental functions, occurs in the late teens.
 Pruning: At about 11 for girls and
12 ½ for boys, gray matter (neurons
and their branchlike dendrites) is
thinned out at a rate of about 0.7% a
year, tapering off in the early 20s.
 Proliferation: At the same time, the
brain's white matter (fatty myelin
sheaths that encase axons) thickens,
making nerve-signal transmissions
faster and more efficient. With each
passing year (maybe even up to age
40) myelin sheaths thicken (Wallis,
2004, para 11).
Brain Maturation in Adolescence
Synaptic Pruning
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Myelination
Improved Brain Function In Teens
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Increased efficiency of local computations
Increased speed of neuronal transmission
Neuron Made Simple: FLUSH!
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Dendrite is like a tree. Also, each
branch is a telephone wire that carries
incoming messages to you.
All or None is like a gun. Fires
completely or not at all.
Myelin is like the insulation that
covers electrical wires.
Neuron is like a silicon chip in a
computer that receives and transmits
information between input and output
devices as well as between other
chips.
Axon is like an electrical cable that
carries information.
Resting Potential is like a battery.
Stable until electrical charge
stimulates it.
Terminal Button is like the nozzle at
the end of a hose, from which water is
squirted.
Synapse is like a railroad junction,
where two trains may meet.
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Like a Toilet Because…
all-or-none principle - the toilet either
flushes completely or not at all; it doesn’t
flush a little or a lot
direction of impulse - the toilet only
flushes one way, the impulse can’t come the
other direction (you hope!)
refractory period - after you flush the
toilet, it won’t flush again for a certain period
of time, even if you push the handle
repeatedly
threshold - you can push the handle a little
bit, but it won’t flush until you push
the handle past a certain critical point - this
corresponds to the level of excitatory
neurotransmitters that a neuron must absorb
before it will fire
resting potential- if you are using a toilet
with a tank, the water in the tank can
represent resting potential. The toilet is
“waiting” to fire, and the water in the tank
represents the overall negative charge inside
the neuron waiting for depolarization
action potential - the action potential is
represented by opening the flap in the tank
and the water draining (flushing) down into
the bowl
Application to Teen Behavior: Pruning
and Proliferation
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Many researches have
speculated that
schizophrenia may be due to
an abnormality in the
pruning process.
MRI studies have shown
that while the average
teenager loses about 15% of
his cortical gray matter,
those who develop
schizophrenia lose as much
as 25% (Wallis, 2004, para
25)
Biological Difference: Prefrontal Cortex
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Often referred to as the “CEO” of
the brain , because it is the in
charge of executive functions,
such planning, strategizing,
setting priorities, organizing
thoughts, suppressing impulses,
weighing the consequences of
one’s actions, and judgment.
The development of the brain
proceeds in stages, generally from
back to front. The very last part of
the brain to reach maturity –
through proliferation and pruning
-- is the prefrontal cortex
(Wallis, 2004, para 13).
Research: Prefrontal Cortex
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In an experiment by Beatriz Luna, director of the Laboratory of
Neurocognitive Development at the University of Pittsburgh, subjects faced
a computer that flashed lights randomly. They were told either to rapidly
focus on the lights or to try to avoid looking at them.
Teens used more of their prefrontal cortex resources than adults did. In fact,
the amount of prefrontal cortex employed was similar to what adult brains
use when performing a much more complex task (Sabbagh, 2006, para 5).
In this visual-motor test, subjects must use the prefrontal cortex to tell the
rest of the brain how to behave. Adolescents are using up prefrontal cortex
like crazy, while adults call on other parts of the brain "to collaborate and
better distribute the workload” (Sabbagh, 2006, para 7).
When teenagers perform certain tasks, their prefrontal cortex, which
handles decision making, is working much harder than the same region in
adults facing the same circumstances and it makes less use of other regions
that could help out. (Sabbagh, 2006, para 2).
Research: Prefrontal Cortex
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In a study at Dartmouth, psychologists gave
adolescents and adults a set of scenarios, in which
they have to decide if they are good ideas or bad ideas
while their brains are scanned.
Doing the laundry. Good idea, bad idea?
Riding your bike down a staircase. Good idea, bad
idea?
Swallowing a cockroach. Good idea, bad idea?
Swimming with sharks. Good idea, bad idea?
 Research found that adults and teens both knew,
for example, that swimming with sharks wasn't
such a good idea. However, teens and adults
come up with different lines of reasoning to
reach their conclusions.
 On their brain scans, adults used the part of the
brain that processes visual imagery to form
answers. In these scenarios adults have a
system, an automatic system, for processing
these types of dilemmas where we instantly get a
visual and we instantly, if it is dangerous or
gross or aversive, we get that pang.
 Teens actually use their frontal cortex, the
cognitive part of their brains to think about the
problems and reach their conclusion. They are
actually trying to think about this. They are
trying to reason about this and it is not automatic
and as a result it is very labored for them
(Bowser, 2004)
Application to Teen Behavior:
Prefrontal Cortex
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The frontal lobe is the final part capable of deciding. An
immature frontal lobe makes it difficult to make a decision if
given conflicting information such as the following decision:
“I'll finish my homework and take out the garbage, and then
I'll IM my friends about seeing a movie” (Wallis, 2004, para
13).
The frontal lobe is the part of the brain for exercising
judgment. Since it is still maturing in adolescence, there is no
part to stop risky, impulsive behavior (Wallis, 2004, para 17)
Since the teen brain relies more the prefrontal cortex,
adolescents may assess and react less efficiently than adults
under challenging conditions (i.e, talking o the phone and
avoiding an accident at the same time). This excessive
reliance on the prefrontal cortex can lead to error, especially
when difficulty increases (Sabbagh, 2006, para 2).
Biological Difference: Sex Hormones
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At puberty,
testosterone-like
hormones released by
the adrenal glands,
begin to circulate and
are extremely active
in brain areas that
regulate mood and
excitability, such as
the limbic system
(Wallis, 2004, 16).
Application to Teen Behavior: Sex
Hormones
Feelings reach a flash point more easily
 Adolescents tend to seek out situations
that create intense feelings and satisfy
their desire for thrills. The problem is that
in a world made up of fast cars, illicit
drugs, gangs and numerous other
dangerous situations, it puts teenager at
great risk (Wallis, 2004, 16).
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Biological Difference: Nucleus
Accumbens
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A region in the frontal
cortex that directs
motivation to seek
rewards.
The nucleus accumbens is
activated by anticipated or
received awards (i.e.,
monetary, chocolate).
A team at the National
Institutes of Mental Health
in 2005 saw that the
nucleus accumbens
responded more in
adolescents than in adults
when they received a
reward (Monastersky,
2007, para 27).
Biological Difference: Dopamine
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One reason the nucleus
accumbens acts up more in
adolescence is due to the different
ways the younger brains deal with
the neurotransmitter dopamine.
Dopamine, the brain chemical
involved in motivation and in
reinforcing behavior, is
particularly abundant and active
in the teen years (Wallis, 2004,
para 21)
In addition to pleasure, novel
situations will cause dopamine to
squirt into the nucleus accumbens.
Application to Teen Behavior: Nucleus
Accumbens + Dopamine
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When new, exciting activities cause
neurons to release neuotransmitters,
such as dopamine, that make you feel
good, risky behavior may produce
emotional rewards, too (Kowalski,
2000, 9). As a result, the reward
system in the adolescent brain may
have tuned teens to seek out new
experiences that create intense
feelings and satisfy their desire for
thrills.
The rapid changes in dopamine-rich
areas of the brain also may be an
additional factor in making teens
vulnerable to the stimulating and
addictive effects of drugs and alcohol
(Wallis, 2004, 16).
Biological Difference: Amygdala
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This area is associated with
emotion, specifically fear,
and gut responses.
New imaging studies
suggest that teenagers, when
asked to interpret emotional
information, use this
reactive part of the brain
rather than the more
“thinking” region, the
frontal cortex, while adults
rely more heavily on the
frontal cortex.
Research: Amygdala
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At the McLean Hospital in Belmont,
Mass., Deborah Yurgelun-Todd and a
group of researchers have studied
how adolescents perceive emotion as
compared to adults.
 The scientists looked at the brains
of 18 children between the ages
of 10 and 18 and compared them
to 16 adults using functional
magnetic resonance imaging
(fMRI).
 Both groups were shown pictures
of adult faces, such as the face to
the right, and asked to identify
the emotion on the faces. (What
emotion do you think is shown?)
 Using fMRI, the researchers
could trace what part of the brain
responded as subjects were asked
to identify the expression
depicted in the picture (Spinks,
2002, para 2)
Research: Amygdala
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Many teen subjects failed to
interpret the emotion in
faces like this one as fear,
while the adults correctly
identified the expression as
fear.
The teens answered
"shocked, surprised, angry."
Furthermore, the teens and
adults used different parts of
their brains to process what
they were feeling (Spinks,
2002, para 3).
Research: Amygdala
When reading emotion, teens (left) rely more on the amygdala,
a small almond shaped region that guides instinctual or “gut”
reactions, while adults (right) rely more on the frontal cortex,
which governs reason and planning (Spinks, 2002, para 3).
Application to Teen Behavior: Amygdala
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Ramifications of Study:
 The frontal cortex helped the adults distinguish fear from shock or
surprise. For the teens, this area wasn't fully operating and thus teens
have a harder time distinguishing a subtlety of expression (Spinks,
2002, para 5).
 May explain why adolescents so frequently misread emotional
signals, seeing anger and hostility where none exists. For example,
teenage ranting ("That teacher hates me!") can be better understood
in this light (Wallis, 2004, para 19)
 Reactions, rather than rational thought, come more from the amygdala,
deep in the brain, than the frontal cortex, which led Yurgelun-Todd and
other neuroscientists to suggest that an immature brain leads to
impulsivity, or what researchers dub "risk-taking behavior“ (Spinks,
2002, para 6).
 Scientists also speculate that this may be why teens have trouble
modulating their emotional responses.
Ramifications
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Use-it-or-lose it principle
 The best estimate for when
the brain is truly mature is 25
(How adolescents spend their
time may be critical.
 Research shows, for instance,
that practicing piano quickly
thickens neurons in the brain
regions that control the fingers
(Wallis, 2004, para 12).
Strategies that help to postpone
sexual activity, binge drinking
and other risky behaviors also
have the virtue of giving the
forebrain and other neurological
structures time to mature. (Reyna,
2006, Para 4)
Ramifications
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Parents and educators need to emphasize more immediate
payoffs to be effective.
 For example, to persuade a teen to quit drinking, parents
and educators need to stress something immediate and
tangible (i.e., the danger of getting kicked off the football
team, say--rather than a future on skid row) (Wallis, 2004,
para 22).
It might also be useful to help adolescents make up for what
their brain still lacks by providing structure (rules and limits),
organizing their time, guiding them through tough decisions
(even when they resist) and applying patience and love
(Wallis, 2004, para 28)
If anything, it is useful for parents and educators to remind
themselves that teenage behavior is not just a matter of willful
pigheadedness or determination to drive people crazy!
Ramifications
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Change the way we treat teenagers:
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adolescents need more scaffolding and
monitoring, such as supervised after-school
programs or restricted driving licenses, to
help them learn how to make good
decisions.
school schedules that force teenagers to
rise earlier than their bodies are naturally
prepared to do and distractions like the
Internet are causing teenagers to run up
significant sleep deficits, which can affect
their ability to moderate their behavior.
Some legal scholars and child advocates
argue that minors should never be tried as
adults and should be spared the death
penalty since they biologically have
increased difficulty making mature
decisions and understanding the
consequences of their actions (Wallis,
2004, para 27)
Ramifications
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Change Intervention Programs
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fuzzy-trace theory: train teenagers to think less logically or rely less on
their prefrontal cortex and think more intuitively or automatically, the
way mature adults do (Reyna, 2006, para 20).
‘social norms’ approach: rather than scare students out of misbehaving,
social-norms educators use survey data on students' actual behavior to
underscore that, when it comes to avoiding risky habits, many students
are already doing the right thing (Viadero, 2006, para 3).
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if teenagers know the truth, they will feel less pressured to engage in
dangerous practices themselves.
Researchers studying the adolescent brain also are looking into ways to
identify teenagers at risk for substance abuse, depression,
schizophrenia, and other psychological conditions.
Is Your Teen Heading for Turmoil?
Parents can complete the following questionnaire on-line to help assess their feelings
and their teen’s behavior. A report with expert guidance and advice will be
generated to address the concerns of the parents.
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I have a feeling that somehow I just don't know my teen any longer.
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I find fault with all my teen's friends, but I excuse my teen.
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I realize that I have begun to accept language, standards, attitudes, and behaviors I
don't like just because it's become too hard to try to maintain what I believe.
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Most times, I decide it's just easier to do the chore myself than to ask, remind, or
nag my teen.
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Sometimes I feel as though I have become the resident drill sergeant or nag.
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I often have a sort of scared, angry, or even just stressed or depressed feeling when
I need to ask my teen what ought to be a simple question.
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I'm always second-guessing and questioning myself - other parents don't seem to
have the same problems as I do! I feel angry, hurt, embarrassed, hopeless, and
sometimes even helpless in relation to my teen.
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I'm worried that my teen may use drugs or alcohol.
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And the hardest questions of all: Do you trust your teen? Do you trust your teen
to keep herself or himself safe? (Maxym, 2001)
Works Cited
Anatomy of the Teen Brain. (2002). Retrieved May 30th, 2007, from Inside the Teenage Brain: a Frontline Web site:
www.pbs.org/wgbh/pages/frontline/shows/teenbrain/art/brain.jpg
Bowser, B. (2004). The Teen Brain. Retrieved May 30th, 2007, from Online NewsHour Web site:
http://www.pbs.org/newshour/bb/science/july-dec04/brain_10-13.html
Kowalski, K. (2000). What’s Inside the Teenage Brain. Current Health, 27(3), 4-5. Retrieved May 20th, 2007, from Ebsco
database.
Maxym, C. (2001). Is Your Teen Heading for Turmoil? Retrieved May 30, 2007, from Inside the Teenage Brain: a Frontline Web
site: http://www.pbs.org/wgbh/pages/frontline/shows/teenbrain/etc/quiz.html
Reyna, V. & Farley, F. (2006). Is the Teen Brain too (Rational?). Scientific American Mind, 17(6). Retrieved May 25th, 2007,
from Ebsco database.
Sabbagh, L. (2006). Hard at Work, No, Really. Scientific American Mind, 17(4). Retrieved May 25th, 2007, from Ebsco database.
Spinks, S. (2002). One reason teens respond differently to the world: Immature brain circuitry. Retrieved May 30th, 2007, from
Inside the Teenage Brain: a Frontline Web site:
http://www.pbs.org/wgbh/pages/frontline/shows/teenbrain/work/onereason.html
Teens at the Wheel. (2007). Retrieved May 30th, 2007, from the Chicago Tribune Web site:
http://www.chicagotribune.com/news/specials/broadband/chi-teens-specialreport,1,197168.htmlstory?ctrack=4&cset=true
Wallis, C. & Park, A. (2004). What Makes Teens Tick. Time, 163(19). Retrieved May 20th, 2007, from Ebsco database.
Viadero, D. (2006). ‘Social Norms’ Seen to Keep Students on Right Track. Education Week, 26(2), 16-17. Retrieved May 20th, 2007, from Ebsco database.