Getting together; how epigenetics and family history predict sensitive caregiving behavior.

Sensitivity to subtle cues from infants* faces and empathic responding to these
signals are considered essential aspects of sensitive parenting; a parenting
style known to facilitate a healthy outcome of children*s social emotional
development (Gilbert et al., 2009; Milner, 2003). Children experiencing
insensitive or harsh parenting practices, show impaired cognitive performance
(Pechtel & Pizzagalli, 2011), altered reward processing, stress reactivity, and
impulsiveness (Andersen & Teicher, 2009; Repetti, Taylor & Seeman, 2002). In
contrast to insensitive parenting practices, parenting styles characterized by
high amounts of sensitivity and warmth, result in improved emotion regulation,
self-esteem, and social-emotional functioning (Morris, Cui & Steinberg, 2013).
These findings clearly demonstrate the importance of social sensitivity for the
outcome of a child*s development. However, what makes people more or less
sensitive to social cues is still largely unknown. In this line of studies, the
aim is to unravel the critical factors predicting social sensitivity.

The first factor that will be studied is a biomarker of particular interest;
(epi)genetic regulation of neuropeptide oxytocin (OXT) activity (Puglia et al.,
2015). Recent studies have shown that OXT administration promotes recognition
of emotional facial expressions and cognitive empathic behaviour (Bos et al.,
2012). As such, sensitivity to this neuropeptide might predict social
sensitivity, and thereby facilitate sensitive parenting (Rilling & Young,
2014). One way to study effects of variation in sensitivity to OXT is by
looking at variation in the OXT-receptor (OXTR) gene. Research has shown that
individuals homozygous for the G allele of OXTR rs53576 polymorphism expressed
greater levels of sensitive parenting (Bakermans-Kranenburg & van IJzendoorn,
2008). However, predictive value of fixed variation in genetic code is limited,
and this might be caused by environmental factors, such as exposure to
insensitive parenting, that affect the expression of the gene without altering
the underlying genetic sequence. It is these dynamic epigenetic effects of OXTR
expression that we plan to investigate in relation to social sensitivity.
Animal studies have demonstrated that variation in expression of the OXTR
predicts altered parenting behavior in the next generation (Champagne, 2011),
but in humans this remains to be tested.

The second factor of interest follows from the studies described above and
concerns how you were raised by your parents. Disturbances in children*s
social-emotional behavior due to insensitive and harsh parenting can result in
reduced parental responsiveness later in life (Lanius, Vermetten & Pain, 2010)
and increases the risk of developing a similar insensitive parenting style
towards one*s own children (Milner, 2003), establishing a cyclic pattern
transmitted over generations (Bailey et al., 2009).

Thus, in the current proposed study we will investigate the effect of how
subjects were raised by their parents and the genetic makeup of their OXT
receptor on key motivational behaviors critical for sensitive parenting. To do
this, we will recruit subjects from the RADAR-sample, which is a sample that
participates in a longitudinal study on child-parent relationships.

To investigate the predictive value of methylation of the OXTR and exposure to
parental behavior early in life on social-emotional behaviour related to
caregiving behavior and its neural underpinnings.

The present study is observational with a correlational setup in which OXTR
gene expression and exposure to parental behavior during childhood is related
to physiological and behavioral measures in response to infant and child
stimuli.

Both EEG and EMG are non-invasive techniques, so there is no need for special
preparation for the subject. Furthermore the EEG and EMG equipment used for
this experiment is not intended for medical purposes (Biosemi, Amsterdam, The
Netherlands). There are no known risks associated with EEG and/or EMG
acquisition. The strain on the participant is the investment in time; about 1
hr. for the measurement, and the additional time required for traveling to the
lab. The study is unique in combining longitudinal data from a cohort study
with epigenetic measures along with experimental paradigms tailored to measure
neural and physiological responses to infant stimuli. As such, it can give
insight into the biological and environmental influences on a core
social-emotional behavioral repertoire underlying human caregiving behavior.
Considering the possible implications of increased insight obtained from
fundamental research on the intergenerational transition of insensitive
caregiving practices, the benefits strongly outweigh the minimal strain on the
participants.