Transcript Insights from Neuroscience into the Effects of Impulsivity and Early

Insights from Neuroscience into the
Effects of Impulsivity and Early Life
Experience on School Readiness
and Social Functioning in Youth
Theodore P. Beauchaine, Ph.D.
Robert Bolles & Yasuko Endo Associate Professor
Associate Chair, Department of Psychology
Child & Adolescent
Adjustment Project
Learning Objectives
1.
Recognize that impulsivity, the trait underlying most cases
of ADHD, has well characterized genetic and brain bases.
2.
Understand that ADHD is as ‘real’ as any psychiatric
disorder.
3.
Appreciate the role that environment plays in shaping
impulsivity into more serious disruptive behaviors.
4.
Be aware that impulsivity places children at risk for
underachievement, school failure, and school dropout.
5.
Recognize that impulsivity is not a trait that children ‘grow
out of’.
6.
Understand that the costs to individuals and society of
ignoring the problem are enormous.
School Readiness
 Set of skills, abilities, and other characteristics that foster
successful transition into school (NICHD).
 Self Regulation.
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Sustained attention.
Inhibitory control over behavior.
Capacity to delay gratification.
Ability to suppress strong emotions.
 Social and emotional competencies.
 Emotion regulation.
 Prosocial behavior and cooperation.
 Basic understanding of emotions in self and others.
 Absence of impulsivity, hyperactivity, and aggression.
Impulsivity Defined
 Behavior that is swayed by emotional or
involuntary impulses.
 Behavior without adequate forethought.
 Tendency to choose immediate over long-term
rewards.
 Engagement in behaviors that are likely to be
punished.
 Persistent reward-seeking behavior.
ALL young children are impulsive!
When is Impulsivity Problematic?
 When it places a child at risk for injury.
 When it interferes with social development.
 When it impedes skill acquisition and learning.
 When it undermines the education and/or
safety of other students.
 When it contributes to school drop out.
 When it eventuates in drug use, incarceration,
and criminality.
When is Impulsivity Problematic?

Functional definitions (DSM-IV).
C. Some impairment from the symptoms is present in two or
more settings (at school and at home).
D. There must be clear evidence of clinically significant
impairment in social or academic functioning.

Statistical definitions (CBCL).
98%
2%
Impulsivity and ADHD
 Impulsivity is highly heritable. About 80% of the variance in
impulsivity is accounted for by genetic factors (e.g., Price et al., 2001).
 Most impulsive children have at least one impulsive parent.
 Heritable impulsivity is the core trait underlying most cases
hyperactive/impulsive ADHD (Barkley 1997).
 Early ADHD predisposes to a host of negative outcomes:
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Academic underachievement.
Social rejection.
Delinquency.
School drop out.
Alcohol and drug use.
Criminality.
Impulsivity Across the Lifespan:
Why Early Identification is Important
school conduct
problems,
suspensions
academic
problems
drug use,
criminality
hyperactivity
oppositionality disengagement
& aggression & withdrawal
preschool
middle-school
delinquent
peer group
incarceration,
recidivism
adolescence
age
Delinquency
 Pattern of repeated rule breaking behavior
and criminality.
 Disengagement from dominant cultural norms
for achievement and behavior.
 Easily bored and often irritable.
 Frequent risky behavior despite high
likelihood of punishment.
 Delinquency often results in incarceration.
Growth in US Prison Population
millions
2.0
1.5
1.0
0.5
0.0
1930
1940
Source: Bureau of Justice Statistics
1950
1960
1970
1980
1990
2000
2005
Current Incarceration Rates
Japan
Switzerland
Sweden
Citizens per 100,000
France
Germany
Netherlands
Italy
Australia
Canada
Spain
England
US
0
100
Source: Bureau of Justice Statistics
200
300
400
500
600
700
800
Disproportionality in Incarceration
Latino
12.55%
Other
6.00%
Black
12.32%
Latino
18.26%
Other
3.11%
Black
43.91%
White
69.13%
US Population, 2000
White
34.72%
Prison Population, 2002
The Human Costs…
 20% of black males and 10% of Latinos serve
prison time.
 In some poor urban neighborhoods, 50% of
black males will go to prison.
 Once incarcerated, limited opportunities for
upward mobility are all but eliminated.
 Recidivism rates approach 60% over 5 years.
 Early intervention is far more effective
than incarceration when impulsive children are
treated before delinquency emerges.
Current Intervention Approaches
 Few impulsive or aggressive children receive
any form of intervention.
 When intervention is initiated, it is usually after
ADHD has progressed to delinquency.
 Those who are treated usually receive some
form of group intervention.
 Special education placements
 Summer school, summer camps
 Institutionalization
 These interventions increase delinquency.
Teacher-reported Delinquency
Group Interventions: Iatrogenic Effects
5
treatment
4
3
2
no treatment
1
Pre-treatment
Source: Dishion et al., 1999
Posttreatment
1 year
2 years
3 years
Intervention Effectiveness by Age
% Responders
100
50
0
Preschool
Adolescence
The Ecology of Adolescent Behavior
Treatment Provider
Neighborhood
School
Peer Group
Extended
Parents
Child
Siblings
Family
The High Costs of Incarceration
 Delinquency is far and away the most costly
mental health concern in the US.
 Cost of incarcerating 1 person for 1 year:
$23,205
 Cost of incarcerating 2 million per year:
$48,000,000,000
 Many states are spending close to 20% of
their annual budgets on corrections.
Interim Summary I
 Impulsivity is among the most heritable of all behavioral
traits.
 Impulsivity interferes with school readiness and places
children at risk for academic failure, social rejection,
eventual drop out, and delinquency.
 Environment plays an extremely important role in shaping
impulsivity into serious conduct problems.
 Impulsive children who grow up in high risk
neighborhoods are at especially high risk for delinquency.
 At-risk children need to be identified early in life in order to
prevent the development of antisocial behavior.
Brain Bases of Impulsivity
Dopamine and Impulsivity
 Almost all genes that have been linked with impulsive
behavior affect dopamine (DA) neurotransmission.
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DAT1 gene
DRD2 gene
DRD4 gene
MAO-A gene
COMT gene
5HTT gene
 Genes do not code for specific behaviors. Rather, they
affect brain functioning, which contributes to broad
behavioral traits, such as impulsivity.
Dopamine and Reward
nucleus
accumbens
ventral tegmental area
The Mesolimbic DA System
Mesolimbic Dopamine Activity
phasic
response
tonic activity
tonic activity
neural
firing
time
reward cue
satiation
The Mesolimbic DA System
 Implicated in all motivated (rewarding)
behaviors.
 Tonic levels associated with mood states.
 High tonic DA activity → positive affectivity
(Ashby et al., 1999).
 Low tonic DA activity → negative affectivity,
irritability (Laakso et al., 2003).
 Activity of the system is experience dependent.
 Repeated phasic activation leads to reduced
tonic activation and sensitization.
Mesolimbic Dopamine Activity
original
response
pattern
reduced
tonic
activity
sensitized
phasic
activity
time
reward cue satiation
Experience Dependence
 Rewarding behaviors that strongly increase
phasic mesolimbic dopamine activity:
 Smoking
 Alcohol use
 Illicit drug use
 Methamphetamine
 Cocaine
 Opiates
 Gambling
 Video games
 These activities down-regulate tonic DA activity.
Effects of Chronic DA Activation
normal
control
alcohol
dependent
normal
control
cocaine
dependent
Dopamine and Impulsivity
 Children with ADHD exhibit low tonic and low
phasic mesolimbic activity (e.g., Sagvolden et al., 2005).
 This is a likely neurobiological substrate of
negative affectivity (Beauchaine et al., 2001).
 Low mesolimbic activity is highly heritable,
predisposing to impulsivity and delinquency.
 Environmental risks during development
exacerbate this effect (e.g., Poeggel et al., 1999).
 Exposure to smoking
 Child abuse and neglect
 Drug use
phasic
response
tonic activity
normal +
ADHD
high stress
environment
reward cue
Assessing Reward Sensitivity

Incentive-motivation (reward) tasks. Simple
computer games in which children
a) make money for correct responses during reward
trials, and
b) make no money for correct responses during
extinction trials.
Task: Fixation
+
Task: Reward
$3.20
Task: Reward
$3.60
Task: Non-Reward
$0.00
Striatal Activity: Reward
Source: Knutson et al., 2001
Striatal Activity: Reward
Control
Source: Scheres et al., 2007
ADHD
Implications I: Learning
 Mesolimbic DA responding integral to associative
learning (Sagvolden, 2005).
 Phasic DA response signals to other areas of brain
that an event is important, and that learning should
take place.
normal
normal associative
learning gradient
ADHD
ADHD associative
learning gradient
Reinforcer
(e.g., praise, intrinsic reward value, etc.)
Implications I: Learning
 Mesolimbic DA involved integrally in associative
learning (Sagvolden, 2005).
 Phasic DA response initiates signal to other areas
of brain that an event is important, and that
learning should take place.
 Impulsive children often require more trials to learn
from external events.
Implications II: Reward Seeking
 Children low in tonic DA activity experience high
levels of negative affect and irritability.
 This leads to impulsive reward-seeking behavior to
up-regulate chronically aversive mood.
 Low phasic DA activity means less pleasure from
reward-seeking behavior.
 This elicits more reward-seeking and predisposes
to delinquency.
 Children in high risk neighborhoods are particularly
susceptible.
Number of Delinquent Acts
Impulsivity & Neighborhood Risk
10
Non-impulsive
Impulsive
8
6
4
2
0
High SES
Source: Lynam et al., 2000
Middle
SES
Low SES
Public
Housing
Impulsivity & Neighborhood Risk
Violent Delinquency
3
Non-impulsive
Impulsive
2
1
0
High SES
Source: Lynam et al., 2000
Middle
SES
Low SES
Public
Housing
Interim Summary II
 Impulsivity is highly heritable (about 80%).
 At the neural level, heritable impulsivity is expressed as
deficient DA responding.
 Low DA gives rise to negative affectivity and irritability.
 These aversive mood states lead to reward-seeking
behavior in efforts to ‘self-stimulate’.
 Environmental risks reinforce brain-based vulnerabilities,
leading to more serious behavior problems:
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

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ADHD.
Conduct problems.
Alcohol and drug use.
Criminality.
Dopamine & Extinction (Non-Reward)
anterior
cingulate
cortex
nucleus
accumbens
ventral tegmental area
The Mesolimbic DA System
The Anterior Cingulate Cortex
 Mid-brain structure with complex functions:
 Allocation of attention to important yet
unanticipated events.
 Coordination of thought and emotion.
 Error detection.
 Error monitoring.
 Extinction learning.
ACC Activity: Reward vs. Extinction
Reward
Extinction
Control
ADHD
Source: Gatzke-Kopp, Beauchaine et al., 2007
Deficient ACC Activity:
Implications for Learning
 Deficient ACC activity during extinction (nonreward) likely gives rise to:
 Problems unlearning previously rewarded
behaviors.
 Response perseveration.
 Poor monitoring of one’s own mistakes.
Summary
 Impulsivity is highly heritable and confers risk for poor school
readiness and problems with self regulation.
 Examining neural processes of impulsive children suggests
deficiencies in both
a. Associative learning of new information, and
b. Extinction (unlearning) of no longer useful old information.
 The same neural deficiencies that affect learning also predispose
to negative affectivity, irritability, and low motivation.
 These neural deficiencies can be detected in preschool, and
confer risk for later delinquency (Crowell, Beauchaine et al., 2005).
 Early intervention is essential because
a. Neural vulnerabilities are amplified by environmental risk.
b. Interventions become increasingly ineffective in older children.
What do Effective Interventions Look Like?
 Parent training for effective behavior
management at home.
Source: Beauchaine, Webster-Stratton, & Reid, 2005.
Parenting & Progression of Impulsivity
Peer
Nomination
Parent
Report
Hyperactivity
Teacher
Report
.54
.06
Conduct
Problems
.77
.59
Coercive
Parental
Discipline
Observed
Nattering
Source: Patterson et al., 2000
Harsh
Discipline
Observer
Impression
Interviewer
Impression
Observed
Behavior
What do Effective Interventions Look Like?
 Parent training for effective behavior
management at home.
 Teacher training for effective behavior
management in the classroom.
 Child training of effective strategies for
managing trait impulsivity.
Source: Beauchaine, Webster-Stratton, & Reid, 2005.
What do Effective Interventions Look Like?
Preventing and Treating
Behavior Problems in Young
Children: A Parent-TeacherSchool Partnership
Carolyn Webster-Stratton, Ph.D.
University of Washington
Department of Family and Child Nursing
Tomorrow, 3:30-5 p.m.
The Prefrontal Cortex
anterior
cingulate
cortex
prefrontal
cortex
nucleus
accumbens
ventral tegmental area
The Mesocortical DA System
The Prefrontal Cortex
The Prefrontal Cortex
 Responsible for ‘executive functions’:
 Long term planning
 Inhibitory control over behavior
 Overriding strong emotions
 Complex reasoning and thought processes.
 Among the last brain areas to develop fully.
 Coordinates with mesolimbic structures to regulate
behavior.
 PFC neurodevelopment is compromised by both
mesolimbic deficiencies and adverse
environmental experiences (e.g., Poeggel et al., 1999).
Gray Matter Development
Source: Gogtay et al., 2004
Acknowledgements
National Institute of Mental Health
University of Washington Royalty Research Fund
Sharon Brenner
Jane Chipman-Chacon
Sheila Crowell
Lisa Gatzke-Kopp
Emily Neuhaus
Penny Marsh
Hilary Mead
Kate Shannon
Jamila Reid
Patrick Sylvers
Carolyn Webster-Stratton
Numerous UW undergraduate RAs
A Similar Talk Can be Viewed on
University of Washington TV:
Brain Science as a Means of
Understanding Delinquency in Youth
http://www.uwtv.org/programs/displayevent.asp?rid=3402
Cardiac Responses to Reward
 Sympathetic nervous system (SNS)-linked cardiac activity
may serve as a proxy for central DA activity:
 Heart rate acceleration facilitates approach behaviors.
 Approach-related behaviors requires energy
mobilization, a function served by the SNS.
 Increases in cardiac output are facilitated by SNSmediated changes in contractile force of the left
ventricle.
 DA infusions into mesolimbic structures induce SNSmediated increases in cardiac output (van den Buuse et al.,
1998).
Assessing SNS-Linked Cardiac Activity
Pre-ejection period
Tonic PEP and Delinquency
98
90
96
86
Delinquent
94
82
92
78
90
74
88
70
Non-delinquent
86
1
2
3
4
5
Adolescents
6
ADHD
7
68
Non-ADHD
1
2
Preschoolers
Phasic PEP During Reward
adolescence
middle school
Non-delinquent
Delinquent
preschool
No conduct
problems
Conduct
Problems
No
ADHD
ADHD