The visual cortex is the part of the brain that is found to play a very important role in the storage of object recognition memory, as well as the conversion of short-term memories into long-term memories. The visual cortex is gravely affected by PTSD. Thickness was also reduced in both sides of the visual cortex and left occipital lobe—the center-front and left-front segments of the brain. Results in subjects who witnessed domestic violence were similar to previously reported results in subjects who experienced childhood sexual abuse, as the primary region affected was the visual cortex. Some people who have been sexually molested continually for years report that they have a difficult time placing a face with a name or a context. They have been injured in the area of memory formation and data collection resulting from threats (perceived or real) derived from incoming visual data.
The amygdala, which neighbors the visual cortex, is the almond-shaped part of the brain that stores your emotional memory. The amygdala informs the body’s fight-flight-or-freeze reaction to the stimulus. It summarily controls the body’s hyperresponsive reactions, especially if the front of the brain is underactive, which is the case for those who suffer from PTSD.
Because metabolic activity is strong in the back of the brain (amydala region) less metabolic activity goes to the front of the brain. When this happens the front and temple regions of the brain that are identified as performing executive functions—verbal acuity, prioritization, and organization will atrophy.
There were multiple studies completed showing the effect of trauma on the brain. However, in March 2012, it was found that using two types of neuroimaging tests (SPECT [single-photon-emission computed tomography] and PET [positron-emission tomography]) showed significant relative decreases in metabolic activity to the left hippocampus (which is responsible for the formation of long-term memories) and in the basal ganglia (which is responsible for movement and habit formation and, when disordered, has been implicated in such issues as obsessive-compulsive disorder and Tourette’s syndrome). The PTSD group also had significantly lower metabolic activity in the areas of the brain responsible for autonomic functions that regulate heart rate, blood pressure, and cognitive and attention-based processing.
These findings also indicate that PTSD can impair someone’s ability to grasp irony or handle spontaneity. Because people with PTSD already have an overactive amygdala, such events could create a heightened fight-flight-or-freeze response. If a person with PTSD is exposed to someone’s anger, she might become more easily defensive, avoidant, or aggressive.
If you have accidentally done something to slight her, she is more likely to assume you meant to hurt her. There is little capacity to grant to the other person the benefit of the doubt. Context is everything, but when the survivor is stuck in hypervigilance, which I have just described, she cannot abstractly understand that larger context.
Mary Ellen Mann
Mary Ellen Mann is a licensed clinical social worker in private practice in Denver (visit www.manncounselinggroup.com). After attending a Christian college, she did her graduate work at Columbia University. Recently she co-founded Last Battle, LLC and helped develop the first interactive website for survivors of sexual violation, www.lastbattle.org, to help survivors, family and friends of survivors, Christian leaders, and professionals who care about this population. Her book, From Pain to Power will be on the market September 22, 2015. Mary Ellen lives in Denver with her husband and their two sons.