How violence shapes us by looking at it alone

Fighting, shootings and burglaries – although many are spared in this country, an international team of researchers has found that only violent impressions influence the brain structure of adolescents. Of course, indirect experiences of violence can have a negative effect on brain development. Scientists found lower intelligence quotient and lower gray matter volume in subjects with frequent indirect violence experiences.

The Max Planck Institute for Human Development and the University of Southern California conducted a joint study on the relationships between stressors in the form of adolescent violence and brain structure. The focus has been on healthy young people, aged 14 to 18, living in high-crime neighborhoods in Los Angeles who have experienced many indirect experiences of violence in their neighborhoods. The results of the study were recently published in the journal "Human Brain Mapping".

Violence Decreases Cognitive Performance

"Previous studies have shown that living in conflict environments has lower cognitive performance and increased risk of mental illness, including Posttraumatic Stress Disorder (PTSD), "said Oisin Butler's first author of the Max Planck Institute for Human Development in a press release on the study." So far, however, there is no study of the extent to which experiences of violence have an effect on adolescent brain development

Pbadive violence affects brain development

L & # The study looked at 65 healthy teenagers growing up in the most criminal neighborhoods of Los Angeles, where all the subjects often experienced violence in the neighborhood without being victims or perpetrators themselves. found a lower than average intelligence quotient and a lower volume of gray matter in the anterior cingulate cortex and lower forehead in adolescents

Deficits in speech capacity and mood disorders

Command in charge These include functions that are particularly important for cognitive control, speech capacity and emotions. "Thinning of the gray matter is part of normal brain maturation," says Butler. The slower this process is, the more time is left for the maturation of cognitive functions. In other studies, researchers want to determine how much stress accelerates gray matter degradation, Butler said. [1965] 911 Victims are Victims and Authors

All have no or even direct violence The subjects have collected many indirect experiences of violence. All witnessed crimes, violence or threats in the immediate neighborhood. The study participants themselves, however, came from intact families, so economically weak. However, they were not directly victims of violence, abuse or neglect at home. "We wanted to make sure that the results were not influenced by other factors, such as mental illness or abuse that are known to be badociated with changes in brain structure," adds Mary Helen Immordino-Yang, from the University of Southern California. IQ and MRI Test

All adolescents underwent an intelligence test and their brain structure was badyzed using magnetic resonance imaging (MRI). According to scientists, the results were comparable to those obtained from a study of the effects of military operations on the brain. In the study with soldiers, it has already been established that the duration of military operations in healthy soldiers is badociated with a reduction of gray matter in the same cerebral region.

"Chronic stress, chronic stress" can affect the brain in good health, "says co-author Simone Kühn, who led the study on military operations at the Max Planck Institute for Development human. The affected brain structures would be similar to those of patients with post-traumatic stress disorder, even if no disease is present in the subjects studied.

Influence of Stress on the Brain

Previous studies on this topic targeted only those already experienced Symptoms emerged. However, the new Max Planck Institute study focuses on the influence of stress on the brain in healthy volunteers. "The majority of the population exposed to violence does not develop any clinical symptoms, such as post-traumatic stress disorder," says Kühn. This would have allowed researchers to draw a much more differentiated picture of stress influences on the brain and thus contribute to the generalizability of research on neuroscientific stress, so Kühn. (Vb)