Transcript Advanced Developmental Psychology

PSY 620P
March 17, 2015
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Parent-child relationships
Peer relationships
School and community influences
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2013
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Children raised in institutions:
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More likely to have deficits in cognitive function
Deficits in language production and comprehension
Elevated rates of ADHD
Difficulties with social functioning
Explanation:
 Deprived environment does not provide adequate
experience for proper brain development
 So expect to see structural and functional neural
abnormalities
 Institutionalization has been associated with variety of
differences in neural structure, differs between studies
 General:
 79 participants (subsample of BEIP study)– (136 total in sample)
 Ages 8-11 years
 Bucharest Early Intervention Project (Bucharest, Romania)
 MRI and EEG on longitudinal study participants
 Conditions (3): Only RCT of foster care for institutionalized children
 Typically developing children in Romania (NIG) n=20
 Children exposed to institutionalized rearing (CAUG)  n=29
 Children previously exposed to institutional rearing but then randomized to high-quality
foster care intervention (FCG)  n=25
 Analyses
 Regression analyses used to examine differences in structural and functional neural
correlates of institutionalization during development
 Mediation analysis used to further delineate proposed relationships
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EEG Studies (BEIP)
 EEG at
▪ Study entry, M= 22 mo
▪ 30 mo
▪ 42 mo
▪ 8 years
 Through typical development, relative increase in α-frequencies
▪ Seen globally (indicates structural changes)
▪ At study entry, those exposed to institution had reduced α-power
▪ At age 8, children placed in foster care younger “caught up” more in
α-power
• Relative reduction in grey
matter volume in children
exposed to institution
compared to unexposed
children
• No significant difference
between those placed in
foster care and those kept
in institution
• Suggests neuroplasticity of
white matter following
environmental deprivation
• Similar pattern for Posterior
Corpus Callosum (CC)
• BUT no significant difference
between those placed in foster
care and those kept in
institution
CAUG group
membership
(Environmentally
deprived
condition)
Total Cortical
White Matter
Volume
(Effect on brain
structure)
Power in αfrequency Band
(Effect on brain
function)
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What do these results say about the effect of
institutionalization on development?
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What kinds of programs might help these
kids and when?
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What other types of assessments and at what
time points might add to these results?
Messinger
(Hane & Fox, 2006)
Rubenstein
Previous research suggests that early human caregiving may affect
the development of the systems that underlie stress reactivity.
Rubenstein
Compare infants based on the quality of Maternal Caregiving
Behavior (MCB; low vs. high)
Hypothesis: Infants who experienced low-quality MCB would
exhibit a pattern of right frontal EEG asymmetry, higher
fearfulness, and less sociability than infants who experienced
high-quality MCB.
Rubenstein
4 months [lab, N = 779]
• Reactions to novelty
• Creation of temperament groups
9 months [lab, N = 185]
• EEG data collected
• Infant fearful response
• Infant positive joint attention
9 months + 2 weeks [home, N = 185]
• Videotaped mother-infant interactions
• Quality of MCB
• Quality of infant affect during mother-infant interactions
Rubenstein
Infant measures obtained at 9 months (lab & home)
No sig sex
differences
Creation of Caregiving Groups (Low and High Quality)
Temperament
group
Maternal-caregiving-behavior group
Low quality
High quality
Control
17
8
Positively reactive
10
10
Negatively reactive
7
7
Rubenstein
MCB and stress reactivity (frontal EEG asymmetry,
fearfulness, and sociability)
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Low-quality MCB group sig
more likely to exhibit a
pattern of right frontal EEG
asymmetry and fearfulness
Low-quality MCB group sig
less likely to manifest
positive joint attention
Differences in stress reactivity a function of temperament groups?
Computed series of one-way univariate ANOVAs and temperament
group had no sig main effects on these results.
Rubenstein
MCB and infant affect during interaction
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Low-quality MCB group
expressed sig more
negative affect while in
care of mothers
Degree of positive affect
did not differ between the
groups
Differences in infant affect during caregiving a function of
temperament? No.
Rubenstein
Results suggest that ordinary variations in MCB may influence
the expression of neural systems involved in stress reactivity in
human infants.
1. Infants receiving low-quality MCB showed more fearfulness, less
positive joint attention, and greater right frontal EEG asymmetry
than infants receiving high-quality MCB.
1. Group differences in stress reactivity were not a result of measured
infant temperament.
1. Infants receiving low-quality MCB experienced more negative affect
during caregiving activities than did infants receiving high-quality
MCB.
Rubenstein
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The study divided infants into two extreme groups: low
quality and high quality MCB groups. Could this division
affect the results?
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The infants in this sample represent a middle-class, lowrisk demographic group, and the measure of MCB
captures ordinary variations in MCB (not extreme
instances of deprivation, abuse, or neglect). Would these
ordinary variations in MCB have the same effect in highrisk populations?
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Quality of infant affect was rated as either positive or
negative. Are there any issues with this coding strategy?
Rubenstein
PSY344
Messinger
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Messinger
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Protection from
predators and . . .
conspecifics
Messinger
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Inherent motivation
Organization of different behaviors
 Doesn’t matter how you get to caregiver
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With single function
In a goal-corrected manner
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Attachment as an organizational construct
Messinger
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Infants form attachments to many caregivers
A hierarchy is assumed
 In which infant turns first to primary caregiver
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Role of fathers
Messinger
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How do we know that attachment represents
an “emotional” bond?
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Primary Drive Reduction Theory
 Preference based simply by having primary needs
(i.e., hunger) met?
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Harlow’s studies and the rejection of “drive
reduction” explanations
 Spitz (1946) noticed that infants in orphanages
(who were adequately nourished but had no
loving attention) did very poorly
 Harlow’s surrogate mother studies examined
relative influence of feeding vs. contact/comfort
on attachment
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Bale-wire mesh
vs.
Terry cloth
Each could be
equipped with feeding
nipple
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Test preference during
times of stress
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From Blum (2003)
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Both wire and cloth
fed spend most of
their time on cloth
surrogate mother
 Regardless of which
“mother” fed you
Messinger
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Ainsworth’s (1978) Strange Situation
 Seven episodes increasing amount of stress (e.g., unfamiliar
environment, unfamiliar adult, brief separation from parent)
 Of interest is how attachment behaviors are organized around
parent
 Attachment classification based primarily on reunion behaviors
See example at:
http://www.youtube.com/watch?v=QTsewNrHUHU
http://www.youtube.com/watch?v=DH1m_ZMO7GU
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Secure Attachment (Type B; 65% in NA)
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Ambivalent/Insecure-Resistant (Type C, 15% in NA)
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Insecure/Avoidant (Type A, 20% in NA)
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Disorganized (Type D, very rare)
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Sensitive/responsive caregiving
 Nurturant
 Attentive
 Nonrestrictive
 Synchronous
 Predictable
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Secure attachment in infancy associated with
a variety of positive developmental outcomes
including:
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Why?
 What are potential mechanisms?
Messinger
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What is infant attachment measuring?
 Caregiver responsiveness vs. child temperament
 Infant emotional reactivity vs. regulation
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One possible theory:
Insecure
Avoidant
Secure
B1, B2 vs B3, B4
Insecure
Resistant
High
Low
Distress Reactivity
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Molecular genetics = objective measure of
distress reactivity and attachment
Common genetic variant
 Short (S) allele – Negative affect, Emotional
Disorders, Reduced Serotonin, Increased
Amygdala Activity
 Long allele variant (LG)— same as S allele
 Long allele noncarriers (LA)
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Determine unique contributions of caregiver quality and
genetic variation (5HTTPLR) on infant attachment at 12
and 18 months
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Caregiver quality will predict secure vs insecure
 More responsive mothers lead to secure babies
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5HTTPLR variation will predict reactivity across security
 S and LG alleles will be more reactive than LA
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155 infants and their mothers
 Maternal Responsiveness at 6m
▪ Home-interactions
 Attachment Classification at 12m and 18m
▪ Strange Situation
 Genetics at 32 years
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If attachment and temperament are stable
constructs, then why aren’t the results the
same at 12 and 18 months?
At the beginning of the article, they laid out
the debate that attachment is either based
on maternal responsivity or infant
temperament. Which do you think is more
important?
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Perceive signals accurately and respond
promptly and appropriately
 22% (r = .22), 7,223 infants in 123 comparisons
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Original Ainsworth subscale
 24% (r = .24), 837 infants in subset of 16 studies
 Socioeconomic class is a moderator
▪ Middle (r = .27); lower (r = .15)
Messinger
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Diathesis-stress model
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Differential-susceptibility model
 Meta-analysis
o Searched for “serotonin” or “5HTT” and “human”
o Studies with behavioral, psychiatric, or developmental outcomes in children under 18
 Extracted 77 effect sizes on 9361 subjects from 30 reports
o 41 concerned vulnerability (e.g., bullying and emotional problems)
o 36 focused on the “bright side” (e.g., high-quality family functioning and alcohol)
 Examined 5 moderators
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Age
Ethnicity
Single-necleotide polymorphism (SNP)
Method of assessing environment
Method of assessing outcomes
ss/sl carriers are more vulnerable to
environmental adversity than ll carriers
 ss/sl carriers did not benefit significantly more
from positive environments than ll carriers
 Age, SNP, and methods were not significant
moderators
 However, ethnicity was a significant moderator
of the association between positive environment
and positive outcomes for ll carriers
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Differential Sensitivity Model
 How different from traditional diathesis-stress
model?
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How do study designs differ based on these models?
 Range of environments?
 Range of psychological and behavioral outcomes?
Kochanska et al., 2007
Bradley & Corwyn, 2008
Pluess & Belsky, 2010
Taylor et al., 2006
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DRD4 - Long Allele
"Long" versions of polymorphisms
are the alleles with 6 to 10 repeats.
Novelty/Sensation Seeking 7R
appears to react less strongly to
Attention Problems/Aggression dopamine molecules.[8]
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 Susceptibility to Parenting
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EEG Asymmetry
http://en.wikipedia.org/wiki/Dopamine_recept
or_D4
 Left Frontal – “Easy”
Temperament
 Right Frontal – “Negative
Reactive” Temperament
 Schmidt, Fox, Perez-Edgar & Hamer
(2009)
Mattson
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DRD4 by Asymmetry
 Susceptibility to
Asymmetry
▪ Soothability
▪ Attention Difficulties
▪ Asymmetry unrelated to
DRD4
▪ Complex Gene-Gene
Interaction?
Mattson
Genes influence relation between
parenting and temperament
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18-21 month olds
DRD4 48 (7-repeat
allele) “long”
Allele increased
sensitivity to
environmental factors
such as parenting.
Lower quality
parenting higher
sensation seeking.
Higher quality  lower
sensation seeking
Parenting quality interacts with genetic
variation in dopamine receptor D4 to
influence temperament in early
childhood Sheese BE, et al. Dev
Psychopathol 2007 19(4):1039-46
Messinger & Henderson
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Future Directions
 Importance of assessing
▪ Environmental adversity AND environmental support
▪ Negative outcomes AND adaptive/positive outcomes
 Consideration of mediating mechanisms
▪ Physiological reactivity and thresholds to respond
▪ Attention biases related to reactivity
 Plasticity as
▪ Gradient?
▪ Domain specific?