Associations Between Childhood Abuse Severity and Fear Learning Processes in Adulthood: Assessing the Role of Vagal Signaling.

Objective: Childhood abuse is known to be a vulnerability factor for psychopathology in adulthood, which is posited to occur, at least in part, through influencing fear learning processes. This study tested a model by which severity of childhood abuse had indirect effects on fear learning processes via vagal signaling as indexed by heart rate variability (HRV).

Methods: A sample of N=123 individuals assigned female at birth (Mage=22.99; 35.8% Hispanic; 45.5% Asian, 27.6% White, 7.3% Other) completed a single study visit during which they completed a fear learning task where physiological measurements were collected. Exposure to childhood abuse was assessed using the abuse subscales of the Childhood Trauma Questionnaire.

Results: Results found that higher severity of childhood abuse was significantly associated with poorer fear/safety discrimination (ß=-0.23, P=0.01), and lower resting HRV was significantly associated with higher initial startle during fear conditioning (ß=-0.17, P=0.047). Notably, a probe of the relationship between the abuse subscales (physical, sexual, and emotional) and fear/safety discrimination found only sexual abuse was significantly associated with poorer fear/safety discrimination (ß=-0.21, P=0.022).

Conclusions: Findings suggest that fear/safety discrimination impairments may be an important physiological marker for survivors of childhood abuse, and that sexual abuse may be more strongly associated with impairments in fear/safety discrimination than other early abuse exposures. A greater understanding of the underlying factors contributing to psychopathology risk in this population is needed.