Current Trends in Current Trends in Understanding the Understanding the Adolescent BrainAdolescent Brain

Shirley Shen, Ph.DShirley Shen, Ph.DClark County Juvenile CourtClark County Juvenile Court

Maturation of the teen brainMaturation of the teen brain

Something more organized that Something more organized that looks like this..looks like this..

Like a remote controlLike a remote control

Cross section of brainCross section of brain

NeuronNeuron

Stages of brain developmentStages of brain development

The infant is The infant is born with an born with an

overproduction overproduction of neuron, much of neuron, much more than the more than the adult brain. adult brain.

Neural connections, Neural connections, however, are not however, are not established during birth.established during birth.

Experiences in the Experiences in the child’s environment child’s environment leads to either leads to either reinforcement (wiring) of reinforcement (wiring) of the neural connections the neural connections or elimination of the or elimination of the neural connection neural connection (pruning)(pruning)

NIMH StudyNIMH Study

Dr. Jay Giedd—National Institute of Dr. Jay Giedd—National Institute of Mental HealthMental Health

Began studying the brain of normal Began studying the brain of normal children and teenagers every two children and teenagers every two years with a fMRI years with a fMRI

Implications of Dr. Giedd’s findings Implications of Dr. Giedd’s findings of the adolescent brainof the adolescent brain

Dr. Giedd found that Dr. Giedd found that prior to prior to adolescence, there adolescence, there is a thickening in is a thickening in the grey areas of the grey areas of the frontal lobe. the frontal lobe.

There are also There are also profound changes in profound changes in the amygdala and the amygdala and also in the nucleus also in the nucleus accumbensaccumbens

Frontal Grey Matter Development Frontal Grey Matter Development in the Adolescent Brainin the Adolescent Brain

Frontal LobeFrontal Lobe

Function of Frontal LobeFunction of Frontal Lobe

Responsible for:Responsible for:Executive functioning tasks Executive functioning tasks

such as: such as: planningplanningstrategizingstrategizingorganizingorganizing

Attention functioning:Attention functioning:maintaining attentionmaintaining attentionshifting attentionshifting attention

Examples of Functional Impairments Examples of Functional Impairments in Frontal Lobe Lesionsin Frontal Lobe Lesions

Short term memory is impaired Short term memory is impaired with easy distraction. with easy distraction.

Impairments in divergent Impairments in divergent thinking (when there are thinking (when there are multiple correct answers). multiple correct answers).

Examples of Functional Impairments Examples of Functional Impairments in Frontal Lobe Lesionsin Frontal Lobe Lesions

Impaired strategy formation and Impaired strategy formation and planning, especially in unfamiliar planning, especially in unfamiliar situations.situations.

There is inappropriate behavior with There is inappropriate behavior with difficulty using social cues and difficulty using social cues and information to direct, control, or information to direct, control, or change personal behavior. change personal behavior.

Inhibition impaired. Inhibition impaired.

The frontal lobe functions as the The frontal lobe functions as the CEO. The adolescent is just learning CEO. The adolescent is just learning how to use the prefrontal cortex. how to use the prefrontal cortex.

However, it is not always very However, it is not always very successful at it. successful at it.

When the frontal lobe is When the frontal lobe is vulnerablevulnerable

When emotions are called on first to When emotions are called on first to solve a problemsolve a problem

During times of peer influence.During times of peer influence.

What is the anatomical reason What is the anatomical reason for thisfor this

The brain is being reorganized during The brain is being reorganized during adolesceneadolescene

The more primitive portions of the The more primitive portions of the brain, such as the sensorimotor brain, such as the sensorimotor region and the region and the emotionalemotional regions regions are already developedare already developed

Beatrice Luna-University of Beatrice Luna-University of PittsburgPittsburg

Adolescent risk takingAdolescent risk taking

Design- Asked both adults and Design- Asked both adults and adolescent to not look at a light adolescent to not look at a light placed in a brain scanner.placed in a brain scanner.

Findings of StudyFindings of Study

AdultsAdults

Able to not look Able to not look at the lightat the light

Used several Used several parts of brain to parts of brain to manage the taskmanage the task

TeensTeens

Able to not look Able to not look at the lightat the light

Solely used the Solely used the frontal lobe to frontal lobe to complete this complete this tasktask

MRI Study by Dr. MRI Study by Dr. Yurgelun-Todd

N=19N=19 Suggestive that the prefrontal cortex Suggestive that the prefrontal cortex

attenuates or monitors what happens attenuates or monitors what happens in the amygdalain the amygdala

ImplicationsImplications

Teens can use their frontal lobe. Teens can use their frontal lobe. However, as they are learning to use However, as they are learning to use

it, they are using it even to do very it, they are using it even to do very easy taskseasy tasks

Teens are not good managers of Teens are not good managers of their frontal lobe.their frontal lobe.

It is as if the manager makes himself It is as if the manager makes himself take on the role of all his employees.take on the role of all his employees.

AmygdalaAmygdala

Function of the AmygdalaFunction of the Amygdala

Emotional center of the brainEmotional center of the brain It has been suggested that the It has been suggested that the

amygdala functions to associate amygdala functions to associate sensation with reward or punishment. sensation with reward or punishment.

The amygdala does seem to be closely The amygdala does seem to be closely associated with the feeling of associated with the feeling of fearfear

Amygdala and the Adolescent Amygdala and the Adolescent BrainBrain

Adolescents tend to use their Limbic System more often in the decision making process, since their Frontal Lobes are not fully developed.

The Amygdala, part of the Limbic System, is responsible for impulse reactions, emotional reactions, fear, and is also used in the decision-making process of adolescents.

Implications of Amygdala on Implications of Amygdala on Adolescent BehaviorsAdolescent Behaviors

Results in adolescents making more decisions based on emotional reactions rather than reasoning.

Less capable ability to weigh long term consequences.

Developing adolescents tend to use their Amygdala when responding to other people’s emotions, yielding more reactionary, less reasoned perceptions of situations than adults.

Teen brain Teen brain Adult brain Adult brain

Nucleus AccumbensNucleus Accumbens

Mortality Rates in Adolescents in Mortality Rates in Adolescents in the U.S. 1979-1988the U.S. 1979-1988

Approximately three fourths of the more Approximately three fourths of the more than 40,000 deaths each year among than 40,000 deaths each year among persons aged 10-24 years in the United persons aged 10-24 years in the United States are related to preventable States are related to preventable causes causes motor-vehicle crashes (37%), motor-vehicle crashes (37%), homicide (14%), homicide (14%), suicide (12%), and suicide (12%), and other injuries (e.g., drowning, poisoning, other injuries (e.g., drowning, poisoning,

and burns) (12%). and burns) (12%).

Function of Nucleus AccumbensFunction of Nucleus Accumbens

Directs motivationDirects motivation Responsible for how much effort an Responsible for how much effort an

organism will expend in order to seek organism will expend in order to seek rewardreward

Also often referred to as the brain’s Also often referred to as the brain’s reward systemreward system

Has significant implications in the Has significant implications in the reward system for drugs in the brainreward system for drugs in the brain

Studies of adolescent response Studies of adolescent response in risk taking-in risk taking-

Wheel of fortune taskWheel of fortune task

Adolescents took significantly more risks Adolescents took significantly more risks than did adults and werethan did adults and were

Adolescents were happier when they Adolescents were happier when they won money, but were less upset than won money, but were less upset than adults when they lost. adults when they lost.

In response to feedback, adolescents In response to feedback, adolescents activated the nucleus accumbens more activated the nucleus accumbens more than did adults, while adults engaged than did adults, while adults engaged the amygdala and PFC more than did the amygdala and PFC more than did adolescents. adolescents.

Teens Perception of Self Teens Perception of Self

Also a function of brain Also a function of brain development development

Who Am I ?????Who Am I ?????Who I am Who I am

depends on who depends on who my friends think my friends think

I am….I am….

My Friends tell me who My Friends tell me who I am sociallyI am socially

Social InfluencesSocial Influences

Who Am I ?????Who Am I ?????

Who I am Who I am depends on who depends on who my parents my parents think I am……think I am……

My parents tell me who I am My parents tell me who I am academicallyacademically

Dr. Jennifer Pfeifer-University of Dr. Jennifer Pfeifer-University of OregonOregon

Two separate types of questions Two separate types of questions were asked while subjects were put were asked while subjects were put in an fMRI scan.in an fMRI scan.

What do I think of myself……(direct self What do I think of myself……(direct self apprasial)apprasial)

What others think of me……..(reflected self What others think of me……..(reflected self apprasial)apprasial)

Study FindingsStudy Findings

When asked what others thought of When asked what others thought of you, both teens and adults used the you, both teens and adults used the medial prefrontal cortex and also the medial prefrontal cortex and also the temporal parietal areas of the brain. temporal parietal areas of the brain.

HoweverHowever

When asked how adults and teens When asked how adults and teens think of themselves, teens continued think of themselves, teens continued to use the same region of the brain, to use the same region of the brain, suggesting that teen’s self appraisal suggesting that teen’s self appraisal is tied into what they believe others is tied into what they believe others think of them. think of them.

Studies on brain vulnerability to Studies on brain vulnerability to drugs and alcohol as it relates drugs and alcohol as it relates

to risk takingto risk taking Susan Anderson-Harvard Medical Susan Anderson-Harvard Medical

SchoolSchool Placed juvenile and adult rats in situation Placed juvenile and adult rats in situation

where they were able to have access to where they were able to have access to cocaine. cocaine.

Young and old rats opted not to be in that Young and old rats opted not to be in that environment, but adolescent rats tended to environment, but adolescent rats tended to be immensely attracted to the situation.be immensely attracted to the situation.

Scott Swartzwelder-Duke UniversityScott Swartzwelder-Duke University 7 million youngsters binge drink once a 7 million youngsters binge drink once a

monthmonth Effects of alcohol has lasting impact on the Effects of alcohol has lasting impact on the

adolescent brain, particularly in the area of adolescent brain, particularly in the area of the hippocampus which is responsible for the hippocampus which is responsible for memory.memory.

Teen brains do not recover as quickly after Teen brains do not recover as quickly after drinking as adults-demonstrated in memory drinking as adults-demonstrated in memory tests 3-weeks post last binge episode. tests 3-weeks post last binge episode.

While their brains are much more While their brains are much more vulnerable to alcohol, it has less sedating vulnerable to alcohol, it has less sedating effects. Teens don’t get tired after effects. Teens don’t get tired after drinking the same way that adults do.drinking the same way that adults do.

Teens are also less vulnerable to Teens are also less vulnerable to balance problems and hangovers balance problems and hangovers from drinkingfrom drinking

Alcohol’s affect on the Alcohol’s affect on the hippocampushippocampus

Receptors are activated by the Receptors are activated by the neurotransmitter glutamate and neurotransmitter glutamate and allow calcium to enter neurons, allow calcium to enter neurons, setting off a cascade of changes that setting off a cascade of changes that strengthen synapses, by helping to strengthen synapses, by helping to create repeated connections create repeated connections between cells, aiding in the efficient between cells, aiding in the efficient formation of new memories. formation of new memories.

But at the equivalent of one or two But at the equivalent of one or two alcoholic drinks, the receptors' alcoholic drinks, the receptors' activity slowed, and at higher doses, activity slowed, and at higher doses, they shut down almost entirely. they shut down almost entirely.

What Do We KnowWhat Do We Know

Drinking during the teen years Drinking during the teen years significantly increases a youngster’s significantly increases a youngster’s chances of becoming alcoholic in adult chances of becoming alcoholic in adult life.life.

Drinking, even moderately in teen years Drinking, even moderately in teen years significantly damage the hippocampus.significantly damage the hippocampus.

The long term damage of drinking in The long term damage of drinking in adolescence is significantly more than in adolescence is significantly more than in the adult.the adult.

These damages are long termThese damages are long term

How brain research affects legal How brain research affects legal ruling for adolescentsruling for adolescents

mandatory life-without-parole sentences for all children 17 or younger convicted of homicide are unconstitutional

Jackson v. Hobbs

“Mandatory life without parole for a juvenile precludes consideration of his chronological age and its hallmark features — among them, immaturity, impetuosity, and failure to appreciate risks and consequences,” Justice Kagan

RelationshipRelationshipRelationshipRelationshipRelationshipRelationship

Have concrete specific goals and tools Have concrete specific goals and tools that will work for one or two days.that will work for one or two days.

Don’t make goals so long that it is not Don’t make goals so long that it is not salientsalient

Make sure that kids are appropriately Make sure that kids are appropriately diagnosed.diagnosed.Most youths in detention have Most youths in detention have contributing academic, learning, contributing academic, learning, mental health or a combination of all mental health or a combination of all of themof them

Make doing well more exciting than Make doing well more exciting than the crime.the crime.

Encourage exercise-exercise Encourage exercise-exercise increased plasticity to brain increased plasticity to brain development.development.

With increased opportunities, the With increased opportunities, the brain will learn to do it better and brain will learn to do it better and quicker.quicker.

ReferencesReferences 1 Giedd JN, Blumenthal J, Jeffries NO, et al. Brain 1 Giedd JN, Blumenthal J, Jeffries NO, et al. Brain

development during childhood and adolescence: development during childhood and adolescence: a longitudinal MRI study. a longitudinal MRI study. Nature NeuroscienceNature Neuroscience, , 1999; 2(10): 861-3.1999; 2(10): 861-3.

2 Rapoport JL, Giedd JN, Blumenthal J, et al. 2 Rapoport JL, Giedd JN, Blumenthal J, et al. Progressive cortical change during adolescence in Progressive cortical change during adolescence in childhood-onset schizophrenia. A longitudinal childhood-onset schizophrenia. A longitudinal magnetic resonance imaging study. magnetic resonance imaging study. Archives of Archives of General PsychiatryGeneral Psychiatry, 1999; 56(7): 649-54., 1999; 56(7): 649-54.

3 Thompson PM, Giedd JN, Woods RP, et al. 3 Thompson PM, Giedd JN, Woods RP, et al. Growth patterns in the developing brain detected Growth patterns in the developing brain detected by using continuum mechanical tensor maps. by using continuum mechanical tensor maps. NatureNature, 2000; 404(6774): 190-3., 2000; 404(6774): 190-3.

4 Sowell ER, Thompson PM, Holmes CJ, et al. 4 Sowell ER, Thompson PM, Holmes CJ, et al. In vivo evidence for post-adolescent brain In vivo evidence for post-adolescent brain maturation in frontal and striatal regions. maturation in frontal and striatal regions. Nature NeuroscienceNature Neuroscience, 1999; 2(10): 859-61., 1999; 2(10): 859-61.

5 Baird AA, Gruber SA, Fein DA, et al. 5 Baird AA, Gruber SA, Fein DA, et al. Functional magnetic resonance imaging of Functional magnetic resonance imaging of facial affect recognition in children and facial affect recognition in children and adolescents. adolescents. Journal of the American Journal of the American Academy of Child and Adolescent Academy of Child and Adolescent PsychiatryPsychiatry, 1999; 38(2): 195-9., 1999; 38(2): 195-9.