The Brain and PTSD

Amber Badgerow

November 15, 2011

PSY 213

John Olmsted

The Brain and PTSD

Question:

Post-traumatic stress disorder (PTSD) is an anxiety disorder that arises from a traumatic event. The effects can be devastating to a person’s life. One of the main issues in PTSD is that a patient is unable to suppress fear even in safe conditions. Also, patients have more vivid memories to the point of reliving the experience. What occurs in the brain that may be associated with the overactive fear and memory response in PTSD?

Prediction:

A person with PTSD may exhibit a hyperactive amygdala, hippocampus, and frontal cortex. These areas are involved with emotions like fear and the formation and storage of emotional memories.

Article 1: “Amygdala activity correlates with attentional bias in PTSD”

This article discusses the study conducted by Myriam El Khoury-Malhame, Emmanuelle Reynaud, Alice Soriano, Keller Michael, Pilar Salgado-Pineda, Xavier Zendjidjian, Caroline Gellato, Fakra Eric, Marie-Noelle Lefebvre, Frank Rouby, Jean-Claude Samuelian, Jean-Luc Anton, Olivier Blin, and Stephanie Khalfa. The study was designed to examine the relationship between the activity of the amygdala, the intensity of PTSD symptoms, and attentional bias in patients with PTSD. During fMRI scanning, seventeen patients with PTSD and seventeen healthy subjects performed an attentional detection of target (DOT) task- where they concentrated on a cross on a screen while quickly locating a dot elsewhere- and a matching task- where they identified whether or not an emotional facial expression or a neutral geometric shape was the same as another. The patients with PTSD exhibited increased amygdala activity when presented with emotional faces and the extent of the activity related to the severity of the symptoms and the degree of attentional bias. Greater attentional bias was also associated with increased activity in the hippocampus and prefrontal cortex. Their results provided additional evidence of hyperactivity in the amygdala in patients with PTSD. They suggested that the increased activity in the amygdala is related to heightened perceptual responsiveness to threats.

Article 2: “Abnormal baseline brain activity in posttraumatic stress disorder: A resting-state functional magnetic resonance imaging study”

Yan Yin, Lingjiang Li, Changfeng Jin, Xiaolei Hu, Lian Duan, Lisa T. Eyler, Qiyong Gong,

Ming Song, Tianzi Jiang, Mei Liao, Yan Zhang, and Weihui Li conducted a study to examine regional baseline brain function in patients with PTSD using fMRI to obtain an amplitude of low-frequency fluctuation (ALFF) measure. They explained that results from previous studies of abnormal brain activity and PTSD differed and that a resting state, without cognitive tasks, would offer more accurate results since it would eliminate more variables. They requested fifty-four patients with PTSD and seventy-two comparison subjects to rest comfortably and not think about anything in particular while having their brains scanned. The team found that there was lower ALFF values in the visual cortex, cerebellum, and right insula of the patients with PTSD compared to the control group. They also exhibited increased ALFF values in the dorsolateral prefrontal gyrus and the ventral medial frontal gyrus. Greater ALFF values correlated with more severe symptoms in patients with PTSD. The decrease in insular and cerebellar activity may be related to inadequacies in memory. Decreased visual cortex activity could be associated with difficulties in verbal memory and visual imagery. The increased activity in the medial prefrontal cortex may have a correlation to mental re-experiencing of traumatic events. Greater activity in the dorsolateral prefrontal cortex could be associated with the vivid recollection of traumatic events that patients with PTSD experience.

Source Validity:

The articles were written by reliable and credible sources. They both presented thorough examples from previous research that added to the accuracy of the results of their study. Despite having a small sample group, both sources controlled well for age and education and had specific criteria for establishing a correct PTSD diagnosis with no history of other mental conditions. The second study further ensured that all patients with PTSD were recent victims and had not been on medication. The second study, however, could have had interference in results from some medicated patients, although they did try to eliminate that possibility with extensive analysis of the data.

Reflection on Hypothesis:

The articles found in this research support my hypothesis that people with PTSD have hyperactivity in the amygdala and frontal cortex. Although the first article mentioned activity in the hippocampus, it was brief and there wasn’t enough specificity to state that it supported my hypothesis. The research added to my prediction in the finding of decreased activity in certain brain regions that may be related to other symptoms of PTSD not focused on in my question.

Works Cited:

Khoury-Malhame Myriam El, Reynaud Emmanuelle, et al. “Amygdala activity correlates with

attentional bias in PTSD.” Neuropsychologia 49.7 (2011): 1969-1973. Elsevier Ltd. ScienceDirect. Web. Nov. 14, 2011.

http://0-www.sciencedirect.com.library.pcc.edu/science/article/pii/S0028393211001709

Yin Yan, Li Lingjiang, et al. “Abnormal baseline brain activity in posttraumatic stress disorder:

A resting-state functional magnetic resonance imaging study.” Neuroscience Letters 498.3 (2011): 185-189. Elsevier Ireland Ltd. ScienceDirect. Web. Nov. 15, 2011.

http://0-www.sciencedirect.com.library.pcc.edu/science/article/pii/S0304394011002606