According to the research article, exposure to violence at home can “represent a form of environmental stress that significantly increases [the] risk of later psychopathology, including anxiety.” It’s as if violence tunes the child’s brain to expect more violence.
Earlier studies have shown that physically abused children show “selective hypervigilance to angry cues,” such as pictures of angry faces. Another earlier study used functional magnetic resonance imaging (fMRI) to show increased brain reactivity. When individuals with anxiety disorder where shown angry faces, two brain regions were overly reactive: the anterior insula (AI) and the amygdala. The same response was found in soldiers exposed to combat.
The new research takes this a step further. Children exposed to family violence, including violence between parents, also showed the same increased brain reactivity. The reaction was quite specific in that they responded to pictures of angry faces, not sad faces.
Most important, perhaps, is that this study looked at brain function rather than symptoms of anxiety or depression. In terms of behavior, the children seemed quite normal. Their brains, however, tell a different story, one of being tuned to be anxious.
Some might suggest that given all the violence in the world, the reaction is beneficial. Maybe it’s a good thing that some human beings learn to be especially responsive to potential threats.
But as the researchers note, excessive reactivity “may also constitute a latent neurobiological risk factor increasing vulnerability to psychopathology.” The researchers also found that the degree of the brain reactivity depended on the severity of the violence.
The research “underlines the importance of taking seriously the impact for a child of living in a family characterized by violence. Even if such a child is not showing overt signs of anxiety or depression, these experiences still appear to have a measurable effect at the neural level,” said Eamon McCrory of University College London, lead author, in a press release from the journal.
More than that, this research shows how violence and trauma affect human beings in ways that permanently alter the brain.
The article, “Heightened Neural Reactivity to Threat in Child Victims of Family Violence,” appears in the December 6 issue of Current Biology.
For previous work by some of these same researchers, see “The Impact of Childhood Maltreatment: A Review of Neurobiological and Genetic Factors,” published in July in Frontiers in Psychiatry.