Vagal Tone, Attachment, and Family Conflict as Predictors of Physiological Reactions to Observed Conflict

1
Vagal Tone, Attachment, and Family Conflict as
Predictors of Physiological Reactions to Observed
Conflict Nancy Darling, Jessica Greenberg,
Rebecca M. Noonan, Andrew R. Burns
Thanks to the many participants who shared their
lives with us and to the students in Advanced
Methods in Adolescent Development who helped
collect data for this project. We would
particularly like to thank Al Porterfield and Jan
Thornton for their invaluable help and
advice. This poster can be downloaded from
http//oberlin.edu/faculty/ndarling/lab/ead.htm.
Abstract
Results
Does RSA, attachment past family conflict
predict adolescents SAM (a amylase) HPA
(cortisol) response? Regression was used to
predict SAM and HPA responses. Results are
reported in Table 2 below.

• Respiratory Sinus Arrhythmia (RSA) is a measure
  of vagal tone, the control of resting heart rate
  by the parasympathetic vagus nerve.
• RSA measures the extent to which the resting
  heart rate fluctuates rhythmically with a
  person's breathing cycle. Normal hearts display
  an increase in rate with inhalation, and a
  decrease with exhalation. A person is said to
  have high vagal tone when their heart rate varies
  significantly for each respiratory cycle.
• Higher baseline RSA is associated with the
  ability to allocate attentional and physiological
  resources efficiently.
• Individuals with high RSA exhibit better
  self-control in times of stress (Porges, 1994) .
• Attachment assesses stable expectations
  individuals have about themselves and others that
  come to organize the encoding, storage,
  retrieval, and manipulation of information
  related to affective states and experiences of
  stress versus security (Mikulincer, 1998).
• Attachment security has two dimensions. Anxiety
  is the extent to which individuals attend to
  environmental threat and, in interpersonal
  relationships, abandonment. Avoidance is the
  extent to which individuals are uncomfortable
  with emotional closeness ((Diamond Hicks,
  2005).
• Secure attachment is associated with low anxiety
  and low avoidance.
• Secure attachment is associated with more
  effective emotional emotion regulation.
• Family Conflict. Past experience in family
  conflict may cause individuals to react
  differently to observed conflict with peers. One
  mechanism through which conflict history may
  affect emotion regulation is through the
  attachment system (Diamond et al., 2006), however
  it may also affect individuals directly through
  learned behaviors and expectations.
• The extent to which individuals have been
  verbally aggressive towards other family members
  may indicate past problems with the regulation
  and expression of negative emotions.
• The extent to which individuals have experienced
  verbal aggression directed towards themselves may
  also change the way in which they experience
  observed conflict as a threat. Past experience
  with high levels of conflict in which the
  individual could not escape, may increase the
  perception of threat and activate the HPA axis.
  Alternatively, prior experience with moderate
  conflict may decrease the perception of conflict
  as personally threatening.

• Do biological, psychological, and contextual
  factors predict late adolescents physiological
  responses to observing conflict?
• Respiratory sinus arhythmia (vagal tone),
  attachment, and mother-adolescent verbal
  aggression were used to predict immediate (GSR
  heart rate) and hormonal (cortisol and a amylase)
  stress responses.
• Psychology and contextual variables appear to be
  better predictors of emotion regulation than
  biological.
• Adolescents who are higher in anxious attachment,
  who worry about being abandoned, showed increased
  heart rate and high a amylase response when
  viewing conflict. Both are signs of SAM
  activation in response to a perceived immediate
  threat.
• Adolescents who reported low family conflict
  those who were seldomly the initiator or target
  of maternal aggression showed an increased
  heart rate and, for maternal aggression higher
  SAM activation (a amylase).
• Adolescents who were more verbally aggressive
  towards their mothers showed greater cortisol
  response (higher HPA activation).

Does RSA, attachment past family conflict
predict adolescents immediate ECG and GSR
response to observed conflict? Hiearchical
linear models (HLM) were used to predict between
person-differences in mean heart rate and GSR
from adolescents anxiety and avoidance, their
reports of their conflictual verbal behaviors
towards their mother, their mothers conflictual
verbal behaviors towards them, and RSA.
Within-person differences in heart rate and GSR
were predicted from segment (music, neutral
discussion, conflict), with the music segment
serving as the baseline comparison. Differences
in adolescents responses to the segments as a
function of attachment, maternal conflict, and
RSA were tested using between-level interactions.
Results are reported in Table 1 below.
Conclusion

• Baseline differences Adolescents with high
  baseline RSA (an indicator of good emotion
  regulation), have lower overall heart rate and
  skin conductance..
• From Baseline to Neutral Heart rate drops from
  baseline as adolescents watch the neutral peer
  interaction. Heart rate decreases are usually
  interpreted as a sign of increased attention to
  novel stimuli. Low vagal tone exaggerates the
  drop in heart rate drop, while high vagal tone
  suppresses it. Interestingly, anxiety has a
  similar effect. High verbally aggression towards
  mothers also exaggerates the decrease in heart
  rate.
• From Baseline to Conflict ECG decreases from
  baseline to conflict. The interactions of
  variables with time need to be interpreted in
  light of the actual heart rates.
• Anxiety High anxiety suppresses the normative
  de-acceleration of heart rate from baseline to
  conflict. All individuals who experience an
  increase in heart rate from baseline to conflict
  are above the mean for anxiety.
• Low anxiety individuals experience large
  decreases in heart rate.
• Family Conflict The heart rates of adolescents
  who rarely experience verbal aggression within
  the family tend to increase. Those who often
  experience verbal aggression tend to decrease.

Introduction

• Cortisol (HPA)
• Adolescents who were verbally aggressive towards
  their mothers reacted more to observed conflict
  (i.e. showed a greater change in cortisol from
  baseline over time) than did their peers.
• Adolescents whose mothers were verbally
  aggressive towards them were less reactive to
  observed conflict.
• a Amylase (SAM)
• Anxious adolescents reacted more to observed
  conflict.
• Adolescents whose mothers were verbally
  aggressive towards them were less reactive to
  observed conflict.

• Conflict between peers is a highly stressful but
  normative experience during adolescence.
  Adolescents ability to regulate emotions in
  response to internal and external demands is
  important in helping them attend to threat
  without being overwhelmed.
• The goal of the current project is to examine the
  extent to which vagal tone (RSA), attachment, and
  prior conflict experiences within the family
  predict late adolescents ability to regulate
  their emotions while observing conflict.
• How does our body react to stress?
• The physiological response to stress depends on
  the balance of two systems. The
  sympathetic-adrenal-medullary (SAM) system
  triggers the body to respond actively to threats
  with fast, short-lived activation of systems.
  This quick response is moderated and dampened by
  the hypothalamus-pituitary-adrenal (HPA) system,
  which acts through the release of glucocorticoids
  (Bauer, Quas, Boyce, 2002). HPA activation is
  slower in onset and of longer duration, and is
  typically triggered by less controllable
  stressors and emotional distress. Individual
  differences in SAM and HPA activation in response
  to stress appear as early as age three (Lundberg,
  1986) and are related to differences in
  physiology, personality, emotion regulation, and
  coping.
• The sympathetic-adrenal-medullary (SAM) system is
  responsible for the fast-acting 'fight or flight'
  component of the stress response.
• SAM activation causes release of catecholeamines
  (epinephrine and norepinephrine) leading to
  arousal and increased blood pressure and heart
  rate.
• The salivary enzyme a-amylase is used to measure
  SAM activity. Levels of a-amylase are directly
  correlated to catecholamine baseline levels and
  to rises in norepinephrine in stressful
  circumstances. (Chatterton et al., 1974).
• Higher levels of a-amylase are associated with
  less secure attachment, social problems, and poor
  stress adaptation.
• The hypothalamic pituitary adrenocortical (HPA)
  axis is the slower acting component of the stress
  response.
• HPA activation is associated with more intense or
  prolonged emotional stress.
• HPA activation stimulates cortisol secretion from
  the adrenal cortex into the blood stream.
• In the short-term, cortisol increases arousal
  and conversion of short-term to long-term memory,
  and dampens the body's own stress response (i.e.
  SAM activation).

Methods
Conclusions
Sample and Procedure Forty-three late adolescent
college students (M age18.9, 26 females) were
recruited from an Introductory Psychology class
to participate in the study. Participants were
scheduled either singly or in pairs and were
greeted by two undergraduate research assistants.
After giving informed consent, participants were
fitted with fetrodes on their arm, clavicle, and
rib to measure heart rate (ECG) and two
electrodes on their non-dominant hand to measure
galvanic skin response (GSR). ECG and GSR data
were collected using portable UFI Biolog units.
Participants were seated in comfortable chairs
and asked to (a) listen to calm, repetitive music
while watching colors changing on a video screen,
(b) view a four minute video of two female
roommates in a dorm setting, and (c) complete a
series of questionnaires. Stimuli were presented
on laptop computers with participants using
headphones to minimize distraction. The video
was scripted to include two sections a neutral
conversation between the roommates that
established their friendly relationship (53
seconds) and (2) an escalating conflict that
begins when one roommate asks the other to help
clean the room and ends with the initiator of the
discussion insulting her roommate, yelling,
threatening to destroy her artwork, and storming
from the room. To control for diurnal
variation in cortisol and a amylase levels, all
participants were scheduled for 300 PM and
completed the procedures prior to 415PM. To
maximize the reliability of the assays,
participants affirmed that they had refrained
from nicotine for seven days, alcohol for 12
hours, dairy products for 3 hours, and food for
one hour prior to data collection.
Measures Anxiety and avoidance were measured
using the Experience in Close Relationship
questionnaire (Brennan, Clark, Shaver, 1998).
Family conflict was measured using verbal
conflict of adolescent towards mother and mother
towards adolescent (Conflict in Relationship
Scale, Wolfe, Wekerle, Reitzel-Jaffe, Lefebvre,
1998). Respiratory Sinus Arhythmia (RSA).
Heart rate variability was measured while
participants listened to calm, neutral music
while watching a moving colored pattern on the
computer screen. RSA (vagal tone) was calculated
using procedures described by Allen (2007).
Galvanic Skin Response (GSR) and Heart Rate
were measured while participants were listening
to music, during the neutral conversation, and
during the conflict conversation. Mean GSR and
heart rate were calculated for each of the three
segments. Data from 10 participants was lost due
to equipment failure. SAM and HPA activation
were measured using salivary assays of a-amylase
and cortisol, respectively. Saliva was
collecting using a passive drool protocol at
three time points prior to listening to music,
19 minutes after the onset of the video (15
minutes after the end of the conflict) and 30
minutes after the end of the conflict. Samples
were frozen immediately after collection and
stored at -40C. Concentrations of cortisol and
a-amylase were measured with a spectrophotometer
following standard laboratory procedures for
Salimetrics kits. Cortisol and a-amylase
response to the observed conflict were measured
by calculating the area under the curve defined
by the three points of measurement.

• Physiological reactions to observing conflict
  were used as markers of emotion regulation.
• Decreases in heart rate from baseline to
  observing conflict were interpreted as a sign of
  attentional focus.
• Increases in heart rate from baseline to
  observing conflict were interpreted as a sign of
  emotional distress.
• Increases in cortisol were seen as a sign of HPA
  activation in response to uncontrollable threat
  or stress.
• Increases in a amylase were seen as a sign of SAM
  activation in response to immediate threat or
  stress.
• Psychology and contextual variables appear to be
  better predictors of emotion regulation than
  biological.
• Adolescents who are higher in anxious attachment,
  who worry about being abandoned, showed increased
  heart rate and high a amylase response when
  viewing conflict. Both are signs of SAM
  activation in response to a perceived immediate
  threat.
• Adolescents who reported low family conflict
  those who were seldomly the initiator or target
  of maternal aggression showed an increased
  heart rate and, for maternal aggression higher
  SAM activation (a amylase).
• Adolescents who were more verbally aggressive
  towards their mothers showed greater cortisol
  response (higher HPA activation).