ACEs and Virtual Sharks: How do Adverse Childhood Experiences Affect Emotional Arousal Under Stress?

Adverse childhood experiences (ACEs) have been linked to a variety of negative life outcomes, with the formation of a maladaptive stress response system as a result of the buildup of toxic stress being described as part of the biological process underpinning this. The results of cortisol research are conflicting as to whether ACEs lead to an increase or decrease in stress response in adult life, as well as whether an additive (linear) or threshold (non-linear) model is appropriate. This study used the stimulus of a virtual reality shark dive in the first experiment to explore whether galvanic skin response (GSR) is impacted by ACE score. Results showed significant differences in GSR between low ACE scorers (0-3 ACEs) and high ACE scorers (4-10 ACEs), with high ACE scorers having a 48% increase in non-specific skin conductance responses (NS-SCR). These results support the existence of a threshold model between ACE score and GSR that occurs at four ACEs, with a non-linear relationship found between ACE score and outcome measures. It is suggested that the maladaptive stress response caused by ACEs operates through the build-up of toxic stress, eventually reaching the point when a neurological threshold is crossed, resulting in a sensitized stress response and the proliferation of stress reactions to non-threatening stimuli.