Maternal buffering of fear-potentiated startle in children and adolescents with trauma exposure

Abstract

Parental availability influences fear expression and learning across species, but the effect of maternal buffering on fear learning in humans is unknown. Here we investigated the effect of maternal availability during fear conditioning in a group of children (ages 8–10) and adolescents (ages 11–13) from a low-income population with a range of trauma exposure. Acoustic startle response data were collected to measure fear-potentiated startle (FPS) in 104 participants. A total of 62 participants were tested with the mother available and 42 when the mother was not in the testing room. We observed that maternal availability during fear conditioning interacted with age to affect FPS discrimination between CS+ and CS–. In line with previous findings suggesting an absence of maternal buffering in adolescents, fear discrimination was affected by maternal availability only in children. Second, we observed that the effect of maternal buffering on FPS discrimination in children was not influenced by maternally reported warmth. In conclusion, we demonstrated that maternal availability improved discrimination in children, regardless of the quality of the relationship. Adolescents discriminated irrespective of maternal status, suggesting that childhood may be a sensitive period for environmental influences on key processes such as learning of danger and safety signals.

Developmental Contributors to Trauma Response: The Importance of Sensitive Periods, Early Environment, and Sex Differences

“…Aspects of the rearing environment can buffer against the negative effects of early-life stress, including trauma [64]. In addition, social buffering provides a powerful protective influence against stress and changes with development such that maternal presence provides greatest buffering influence through middle childhood and less so during adolescence [80]. Importantly, the potential to benefit from social support in adulthood is thought to depend on maternal availability during childhood [82].…”

“…In an fMRI study, children showed dampened amygdala activation to pictures of their mother compared to pictures of a stranger, whereas there was no difference in adolescents [79]. In another study that used fear conditioning of startle responses, children showed an attenuated fear response to a safety signal when the mother was available during conditioning [80]. However, when the mother was not in the same room, children were not able to discriminate danger and safety signals.…”

“…However, when the mother was not in the same room, children were not able to discriminate danger and safety signals. Importantly, the effect of maternal buffering was only observed in children and not in young adolescents [80]. This is most likely explained by the functional emergence of the prefrontal cortex, which is important for learning to discriminate fear and danger and inhibiting the fear response when appropriate [81].…”

“…Enriched environments and maternal or other social support during development promote adaptive stress responses. A recent finding that maternally reported warmth did not impact the effects of maternal availability on fear conditioning in children with trauma exposure [80] suggests that the quality of the mother-child relationship may not be as important as maternal availability. It is clear that childhood is a particularly sensitive period for environmental influences.…”

Child trauma exposure and psychopathology: mechanisms of risk and resilience

“…Cues that signal maternal presence are associated with dampened amygdala reactivity and greater mPFC-amygdala functional connectivity in children, particularly those who have a supportive relationship with their mother [40]. Similarly, maternal presence enhances threat-safety discrimination during fear conditioning in children [41]. Critically, amygdala reactivity to threatening cues following trauma exposure is weaker in children with high maternal support [42].…”