Transcript Brain and Behavior

Biological Foundations
of Misconduct
Missouri Juvenile Justice Conference
October 2012
Special Thanks to:
Dr. Barbara Sullivan (Utah Addiction Center)
The Dana Foundation
The challenge of
working with Adolescents
• Parents and professional alike
have been puzzled for years………
• Is this NORMAL teenage
“baloney”
or is it pathological?
Most common mistake?
• Viewing Adolescents as small
adults
• Physical size
• “Act your age”
• Not only physical, emotional,
moral social, but neurological
According to the CDC, 27,000 people
between the ages of 10 and 24 die from
bad decisions – primarily accidents,
homicide, and suicide…… (Anderson & Smith (2005)
.
The adolescent years, in particular, are a
period of heightened vulnerability to
reckless behavior that occurs despite the
fact that adolescents are more
cognitively mature than children……….
(Spear 2000).
Actuarial tables indicate that adolescents and
young adults are more likely to drive recklessly
and are more likely to drive under the influence of
alcohol or drugs…………
(Arnett J , 1993).
Viewed in hindsight, many of these adverse
outcomes seem to be a result of a poor decision.
Although nobody is immune from making bad
decisions, adolescents and young adults seem to
make a disproportionate share of ultimately fatal
or debilitating ones; indeed, bad decisions are the
greatest cause of morbidity and mortality in
adolescents.
(Berns, Moore & Capra, 2009)
• Earliest attempts to explain behavior
of human beings…………..
• Demonology
• Trephaning
Possession
The notion that psychopathology was
caused by a possession of a spirit or god
was a prevailing theory of mental illness
throughout history.
DEMONOLOGICAL MODEL
The demonological model, as an
explanation of psychopathology, has
existed since the beginnings of
humanity.
…..the causes of mental illness are due
to "spirits" entering the body and
causing the host to become possessed.
The cure would be to release the spirit
from the individual.
The methods for this were accomplished
in several different ways including
trephaning,
exorcism , and a number of
purgative techniques , that would
make the host's body unpleasant for
the spirit.
Trephaning
was a technique used even in the
prehistoric period.
A small round hole in the skull would be made
in order that the evil spirits could be released.
Ironically, this technique could have been
successful for certain kinds of
psychopathology……….…
• The hole in the skull would
have reduced the pressure
on the brain caused by
edema, or swelling,
• eliminating the peculiar
behavior, or "releasing the
spirit".
Biological roots
•Hippocrates
“Humours”….(humors)
Chemical imbalance
The Greek physician Hippocrates,
c. 460 - 377 B.C,
is often called the
“father of medicine”.
Perhaps the most important idea
associated with Hippocrates is that of
relying on facts, clinical observation and
experiment.
HIPPOCRATES AND THE
BIOLOGICAL MOVEMENT
Hippocrates had the notion that
psychopathology was due to
disturbances within the
balances of the
four humours.
The Four Humors consisted
of
BLOOD,
PHLEGM,
YELLOW BILE and
BLACK BILE, that are produced
by several organs throughout
the body.
•
Diseases were caused by
the over or under
manufacturing of one of
these substances causing
disharmony.
Perspectives
• Today we have several perspectives as ways of
explaining human behavior
• Psychology has multiple theories of explanation:
– Biological
– Psychodynamic
– Behavioral
– Humanistic
– Cognitive
– Evolutionary
Biological Perspective
• Study the physiological mechanisms in the brain
and nervous system that organize and control
behavior
• Focus may be at various levels
– individual neurons
– areas of the brain
– specific functions like eating, emotion, or
learning
• Interest in behavior distinguishes biological
psychology from many other biological sciences
Brain Has Evolved
The Human Brain Weighing roughly three pounds, the human brain is about the size of a
small cauliflower. Although your brain makes up only about 2 percent of your total body
weight, it uses some 20 percent of the oxygen your body needs while at rest. The oxygen is
used in breaking down glucose to supply the brain with energy.
BRAIN FACTS
• Brain weighs
approximately
3 pounds
• Brain has
approximately 100
billion neurons and 1
trillion supporting cells
• Neurons grow and
organize themselves
into efficient systems
that operate a lifetime
• Brain controls ALL
activities
• Emotion and cognition
are intertwined
• Neurons can re-route
circuits
• Brain and environment
involved in delicate
duet
• Brain never stops
adapting and changing
CHALLENGE OF UNDERSTANDING
THE BRAIN
• What is the link between the
anatomy of a brain and the
workings of the mind—our
thoughts, emotions, memories, and
behaviors?
• There are no moving parts—it does
not operate mechanically as our
hearts, legs, hands, and lungs do.
The Parts of the Human Brain
Focus
•“White Matter”
•Frontal Cortex
•Caudate nucleus
•Limbic System
–Amygdala
Two Major Developmental
Periods of Brain
• First 3 years of life
• Second burst about 11 for girls and 12
for boys
– Shaping White Matter
• Full development about 25
By age six, the brain is
already 95 percent of
its adult size.
Brain size does not equal
intellectual or
emotional maturity
Although the brain is 80 percent
developed at adolescence, research
indicates that brain signals essential for
motor skills and emotional maturity are
the last to extend to the brain’s frontal
lobe, which is responsible for many of
the skills essential for driving.
Structure of neurons and brain cell
Gray matter: areas of the nervous
system where the nerve fibers are
unmyelinated
White Matter: areas of the nervous system
composed mostly of myelinated nerve fibers
(those having MYELIN SHEATHS) constituting the
conducting portion of the brain and spinal cord.
White matter contains the protein
myelin, which coats neurons' spindly axons
as they reach toward other areas of the
brain. Myelin is important for efficient
signaling between neurons, and it is known
to grow considerably between childhood and
adulthood.
The Myelin Sheath of a neuron consists
of fat-containing cells that insulate the
axon from electrical activity.
When adults reach age 20,
white matter begins to spread,
from the back of the brain
forward, usually completing
this process between 25 and 30
years of age.
One of the most familiar
“white matter deficiency”
diseases………….
Multiple Sclerosis
Researchers have found a connection
between increased white matter
and reduced impulsivity
Young people whose brains
mature early might be more
prone to engage in adult
activities and choices.
White matter of a 20-year-old man
contains a staggering 176,000 km of
myelinated axons
(Marner et al., 2003).
Axons ensure smooth communication
throughout the brain in two important
ways: by conducting electrical impulses
and by transporting various molecules
and organelles from the cell body to the
synapse
(Barry et al., 2007).
Hence, the importance of
maturational changes in white
matter (WM) during childhood
and adolescence for the child's
cognitive development and
mental health
Perrin, Herve, Leonard, et al……2008
"White matter is composed of bundles of
myelinated axons connecting grey matter areas
of the brain, and has been shown to continue to
develop throughout adolescence. These
systematic changes in white matter organization
reflect not only maturation of interconnections
but continued maturation of the brain as a
whole."
"White matter, and its integrity, are essential to
the efficient relay of information within the
brain…………
"Indicators of white matter integrity
are linked to performance on a range of
cognitive tests, including measures of
reading, copying complex figures, and
speeded coding of information.
Abnormalities in white matter health
could relate to compromised ability to
consider multiple sources of information
when making decisions, and to
emotional functioning."
Susan F. Tapert, associate professor of
psychiatry at the University of California
The white matter revelation has led some
safety experts to suggest raising the minimum
driving age to 18. But others have said this is
an unnecessary change that would place an
undue burden on parents.
What’s more common is a push for the
implementation of stricter graduated licensing
laws, which would impose a multi-tiered
licensing system to ease teenagers in to the
responsibilities of driving without a parent in
the car.
"Use it or lose it" principle
Dr. Jay Giedd
Those cells and connections that are used will
survive and flourish. Those cells and connections
that are not used will wither and die.
So if a teen is doing music or sports or academics,
those are the cells and connections that will be
hard-wired.
If they're lying on the couch or playing video games
or MTV, those are the cells and connections that
are going to survive.
The brain undergoes a significant
structural re-modeling process which
includes a substantial increase in white
matter, and an overall decrease in grey
matter attributable to the activitydependent process of synaptic pruning.
Tom Wasiuta
-In many ways adolescence is the healthiest
time of life. The immune system, resistance to
cancer, tolerance for heat and cold and several
other variables are at their peak.
-Despite physical strengths, however, illness
and mortality increase 200 percent to 300
percent.
-As of 2005, the most recent year for which
statistics are available, motor vehicle accidents,
the No. 1 cause, accounted for about half of
deaths. Nos. 2 and 3 were homicide and
suicide.
Jay N. Giedd, M.D. , National Institute of Mental Health.
Maturation of the Prefrontal Cortex
• The prefrontal cortex is often referred
to as the “CEO of the brain.”
• This brain region is responsible for
cognitive analysis and abstract
thought, and the moderation of
“correct” behavior in social
situations.
“Executive functions” of the human
prefrontal cortex include:
• Focusing attention
• Organizing thoughts and problem
solving
• Foreseeing and weighing possible
consequences of behavior
• Considering the future and making
predictions
• Forming strategies and planning
• Ability to balance short-term rewards
with long term goals
• Shifting/adjusting behavior when situations
change
• Impulse control and delaying gratification
• Modulation of intense emotions
• Inhibiting inappropriate behavior and initiating
appropriate behavior
• Simultaneously considering multiple streams
of information when faced with complex and
challenging information
U.S. Department of Health & Human Services
FRONTAL LOBE
• Seat of personality, judgment, reasoning,
problem solving, and rational decision making
• Provides for logic, understanding of
consequences, and emotional/behavioral
regulation
• Governs impulsivity, aggression, ability to
organize thoughts, and plan for the future
• Controls capacity for abstraction, attention,
cognitive flexibility, and goal persistence
• Undergoes significant changes during
adolescence — not fully developed until mid
20’s
(Giedd, 2002)
COMPONENTS OF EXECUTIVE FUNCTIONS AND
SAMPLE BEHAVIORS
COMPONENTS
Goal Directedness
Initiation/Inhibition
Flexibility/Perseverance
BEHAVIORS
Establishing and
maintaining goals;
evaluating progress, using
strategies
Initiating behavior
independently, self-cueing,
inhibiting inappropriate
behaviors
Generating novel
possibilities, flexibility,
performing contingency
based revisions, strategizing
COMPONENTS
BEHAVIORS
Abstract Reasoning
Using rule-guided
thinking, forming
concepts, using
hierarchical and temporal
relationships
Reward Appraisal
Evaluating reward
likelihood, using reward
appraisal to guide
behavior
Social Appraisal
Understanding social
norms and cues,
incorporating social
information into decision
making
Brown et al., 2008
The Amygdala
• Responsible for:
– arousal,
– regulation of emotion,
and
– the initial emotional
response to sensory
information.
• Plays important role in
– mediating anxiety and
depression.
– emotional memory.
ADOLESCENCE
• Adolescence is much broader and longer
than the teenage years alone (has
changed significantly over the past 150
years)
• Adolescence now stretches across more
than a decade, with pubertal onset often
beginning by age 9-12 and adult roles
delayed until mid twenties
(Worthman, 1995)
• Adolescence is a TRANSITIONAL
period during which a child is
becoming, but is not yet, an adult
• Adolescent brains are far less
developed than we previously
believed
• Normal adolescent development
includes conflict, risk taking, facing
insecurities, creating an identity,
mood swings, self-absorption, etc.
ADOLESCENCE
• Most elements of cognitive development
show a trajectory that follows age and
experience rather than the timing of
puberty
(Dahl, 2004)
• Research (eg, Martin, 2003) demonstrates
a significant positive correlation
between pubertal maturation and
sensation seeking
PUBERTY
Romantic motivation
Sexual interest
Emotional intensity
Sleep cycle changes
Appetite
Risk for affective
disorders (girls)
Increase in risk taking,
sensation seeking, and
novelty seeking
Dahl, 2004
AGE/EXPERIENCE
Planning
Logic, reasoning
Inhibitory control
Problem solving
Understanding
consequences
Affect regulation
Goal setting and pursuit
Judgment and abstract
thinking
ADOLESCENCE VS. ADULTS
• Being a responsible adult requires developing selfcontrol over behavior and emotions– must be able to
appropriately inhibit behaviors despite STRONG
FEELINGS
• The ability to integrate these multiple components of
behavior, cognition, and affect in the
service of long term goals involves
neurobehavioral systems that are
among the last regions of the brain to
fully mature
(Dahl, 2004)
• The most widely implicated factor
associated with maladaption vs. resilience
in adolescence is REGULATORY CAPACITY
(RC)
[Kupfer & Woodward, 2004]
• Behavioral control (RC) requires
tremendous effort; adolescents need
practice being consistent and integrating
RC
• White matter development is needed for
regulatory capacity
In the heat of the moment, teen
decision-making can be overly
influenced by emotions, because their
brains rely more on the limbic system
(the emotional seat of the brain) than
the more rational prefrontal cortex
– Sheryl Feinstein, author of Inside the Teenage Brain:
Parenting a Work in Progress (Rowman and Littlefield,
2009.)
Critical Differences Between Adult
and Adolescent Thinking
• Jay Giedd and his colleagues have given
us a new window into understanding
how the pre-adolescent brain develops.
It confirms what other neuroscientists
have outlined over the past 25 years -that different parts of the brain mature
at different times.
• In particular, it corroborates the work of
neuroscientists like Peter Huttenlocher who
have shown that the frontal cortex of human
beings matures relatively late in a child's life.
•
http://www.pbs.org/wgbh/pages/frontline/shows/teenbrain/work/adolescent.html
Why is it that a young person is not
able to drive a car until 16, vote
until 18, drink alcohol until 21, rent
a car from a commercial agency
until 25, but in some states,
can stand trial for murder at
age 12 or 13?
(Dahl, 2004)
• Underdevelopment of the frontal
lobe/prefrontal cortex and the limbic
system make adolescents more prone
to “behave emotionally or with ‘gut’
reactions” (Yurgelun-Todd, 1999)
• Adolescents tend to use an
alternative part of the brain– the
AMYGDALA (emotions & aggression)
rather than the prefrontal cortex
(reasoning) to process information
Illustration by Lydia Kibiuk, 2003
• Amygdala and nucleus acumbens (limbic
system within the temporal lobes) tend to
dominate the prefrontal cortex functions–
this results in a decrease in reasoned
thinking and an increase in impulsiveness
• Because of immature brains, adolescents do
not handle social pressure, instinctual
urges, and other stresses the way adults do
• A major part of adolescence is learning how
to assess risk and consequences —
adolescents are not yet skilled at these
tasks
(Dahl, 2004)
Hot/Cold Cognition
• Hot cognition is a relatively new
psychological term describing the mental
processes that occur when emotions and
personal goals influence judgment.
• Unlike cold cognition that is purely
intellectual, it often relies on biases,
hunches, feelings, intuition, “gut feelings,”
and heuristics.
• People are especially likely to rely on this type of
processing when making decisions that involve
powerful emotions and self-interest.
HOT AND COLD COGNITION
• Thoughts and emotions are intertwined –
teens need to develop a balance between
cognitive and affective systems of the brain
• “COLD” cognition refers to thinking under
conditions of low emotions and/or arousal
• “HOT” cognition refers to thinking under
conditions of strong feelings or arousal
• Decisions made under conditions of strong
affect are difficult to influence by cool
rational thought alone
• Decision making in teens cannot be fully
understood without considering the role
of emotions and the interaction between
thinking and feeling
(Dahl, 2003)
• Teen decisions are unlikely to emerge from a
logical evaluation of the risk/benefits of a
situation – rather decisions are the result of a
complex set of competing feelings – desire to
look cool, fear of being rejected, anxiety about
being caught, excitement of risk, etc.
• Adolescent brain is a “vulnerable”
system that could fail under “hot”
high demanding situations – where
the circuitry is not sufficiently
established to sustain adult level
cognitive control of behavior in the
face of heightened states of
emotion, motivation, distracting
stimuli, or competing tasks
•
(Luna & Sweeny, 2003)
Researchers know that the integrity of
the brain's white matter is compromised
in adult alcoholics, but it is unclear when
during the course of drinking white
matter abnormalities become apparent.
A study of adolescent binge drinkers has
found that even relatively infrequent
exposure to large doses of alcohol during
youth may compromise white matter
fiber coherence.
Susan F. Tapert
• PFC is linked to the ability to inhibit
impulses, weigh consequences,
prioritize, and strategize – this area is
still “under construction” until late
20’s
(Giedd, 1999)
• Wernicke’s area (reception of speech)
and Broca’s area (production of
speech) undergo substantial changes
during the teen years – impacts
ability to listen and express oneself
• Adolescents are not very skilled at
distinguishing the subtlety of facial
expression (excitement, anger, fear, sadness,
etc.)—results in a lot of miscues—leads to
lack of communication and inappropriate
behavior
• Differences in processing, organization, and
responding to information/events leads to
misperceptions and misunderstanding verbal
and non-verbal cues
• To appreciate consequences of risky
behavior, one has to have the ability to
think through potential outcomes and
understand the permanence of
consequences,
• due to an immature prefrontal cortex,
teens are not skilled at doing this
• Teens do not take information, organize
it, and understand it in the same way
that adults do—they have to learn how
to do this
ADOLESCENT BRAIN DEVELOPMENT
• Important to understand that teens often fail
to heed common sense or adult warnings
because they simply may not be able to
understand and/or accept reasons that seem
logical and reasonable to adults (difference in
evaluating positive & negative consequences
{Fromme et al., 1997})
• Adolescents may know “right from wrong”,
but they may not be able to prioritize when
stressed with social/peer pressure
• NEVER assume that you and a teen are
having the same understanding of a
conversation
Phineas Gage
• Gage was a railroad
construction foreman
• An 1848 explosion forced a
steel tamping rod through his
head
• Others said he was “…no
longer Gage…”
• Lost his job, worked as a
sideshow exhibit
Phineas Gage………….
• Damage to orbitofrontal area—
• Impaired sensitivity to risk,
reward, and punishment
• Impulsivity and insight
• Lash out in response to
perceived slights
A Model of Gage’s Injury Computer simulated
reconstruction of Gage’s skull by Damasio and her colleagues (1994) suggests
that Gage’s left and right frontal lobes were both damaged.
Frontal Lobe Injury
• Phineas Gage
• http://www.youtube.com/watch?v=5B2pQkq
M6nc&feature=related
The Prefrontal Cortex in Close-Up
• Phineas Gage: His accident led to major personality
changes
• Prefrontal cortex: brain region particularly concerned with
social phenomena (e.g., following norms). Patients with
injury to this region often have profound disturbances in
their ability to get along with others
• Lobotomy: deliberate damaging of the prefrontal cortex;
used in the late 1940s early 1950s
• Left patients lethargic and emotionally flat, and much easier to manage in
mental hospitals, but it also left them disconnected from their social
surroundings
• As the “prefrontal cortex” area of the
frontal lobe matures, through experience
and practice, teens can reason better,
develop more impulse control, and make
better judgments
• Prefrontal cortex is one of the last areas
of the brain to fully develop (Sowell,
2001)
• Increased need for structure, mentoring,
guidance
Anderson RN, Smith BL (2005) Deaths: leading causes for 2002. Hyattsville,
Maryland: National Center for Health Statistics.
Spear LP (2000) The adolescent brain and age-related behavioral
manifestations. Neurosci Biobehav Rev 24: 417–463.
Arnett J (1993) Reckless behavior in adolescence: a developmental
perspective. Developmental Review 12: 339–373
Adolescent Engagement in Dangerous Behaviors Is Associated with Increased
White Matter Maturity of Frontal Cortex. Berns, Moore &I Capra