Stroop Effect Summary

Diagnosing and Treating PTSD with the Stroop Effect
Yoel Alperin
Riverwood International Charter School

Many studies have been conducted about the Stroop Effect and about Post-Traumatic Stress Disorder, however few discuss how the two are related. It’s not surprising that researchers don’t see the two as having any effect on each other and on the surface that is true. It’s hard to believe that a famous study explaining inhibition has any relation to a terrifying disorder caused by extreme trauma. Post-Traumatic Stress affects 2.4% of the United States and is found in 8% of men and 20% of women in the Army. These two seemingly distant ideas are very much alike. The Stroop Effect can be used to diagnose and treat Post-Traumatic
Stress Disorder patients.
The Stroop Effect Since birth, we are taught that certain words are connected with certain ideas. For example, the word R-E-D is associated with the color of the wavelength of light from approximately 620-740 nm on the electromagnetic spectrum (Bohren, 2006) or in simpler terms, the color of stop signs, roses and strawberries. What if after you have connected the word RED to this certain color, the word changed to A-H-P-A-H, a nonsense syllable? Kline (1921) created a theory of inhibition that says: “If a is already connected with b, then it is difficult to connect it with k, b gets in the way.” In the example above, anyone who is accustomed to R-E-D being associated with the color red, would have difficulty connecting the color red to AHPAH. This theory is not just specific for colors. Any example involving concepts or routines makes sense in the law. In Stroop’s (1935) interference article, it was discovered that there is more interference in color naming then color reading. The experiment described in the article tested whether there was more interference from words or from colors (Stroop, 1935). Two tests were administered each with a separate control. The RCNd test determined how fast one could read color names where the color was different from the color name while the NCWd test determined how fast one could name colors where the color of the word was different from the word on the page. The mean time for 100 responses increased from 63.3 seconds on the RCNd test to 110.3 seconds on the NCWd test or an increase of 74% (Stroop ,1935). The inhibition law (Kline, 1921) was further proven by the fact that because subjects had previously connected a color with the word it represents, it was more difficult to name a color that was connected to a word it did not represent because of pre-determined connections. A variation of the Color Stroop Task, called the Emotional Stroop Task, focuses on the inhibition of specific words rather than on the inhibition of color. Created by Gotlib and McCann (1987), the Emotional Stroop Task examines the inhibition of specific words to patients with certain disorders. The words used on the test are changed when testing a specific disorder. For example, when testing a patient diagnosed with depression, the words on the test would read; suicide, alone, sad, gray, etc. Gotlib and McCann (1978) found that the patients taking the test experienced high inhibition because of the self-relevance of the words. The Emotional Stroop Test has been modified for use in countless studies.
Post-Traumatic Stress Disorder PTSD, or Post-Traumatic Stress Disorder, is a psychiatric disorder that can occur following the experience of life-threatening events including but not limited to military combat, natural disasters, terrorist incidents, car accidents, or physical or sexual assault. Some trauma survivors, return to a normal state after a short period of time; however, some people have stress reactions that do not go away on their own and sometimes may get even worse. These stress reactions are called PTSD (NIMH). PTSD is caused by three regions of the brain; the amygdala, the medial prefrontal cortex, and the hippocampus (Shin & Handwerger, 2009). The amygdala is a medial temporal lobe brain structure located at the end of the hippocampus that helps detect the threat of doubtfulness in the environment. When it senses fear, it predicts an aversive stimulus (such as shock), and starts the process of fear conditioning, a process that supports the body to keep it from going into complete shock (Davis & Whalen, 2001). Some effects of this process are freezing, increased startle or increased skin conductance (Davis & Whalen, 2001). Neuroimaging studies of PTSD have reported exaggerated amygdala activation in response to personal trauma-related memories.
The second cause of PTSD is related the medial prefrontal cortex (MPFC). The MPFC is located at the front of the brain. There are many functional roles of the MPFC though only one is relevant to PTSD. Parts of the medial prefrontal cortex are activated during emotion regulation (Ury et al., 2006). Studies have shown diminished activation in ventral medial prefrontal cortex in PTSD meaning that people with PTSD have little emotion regulation and control.
The third part of the brain involved in PTSD is the hippocampus, a medial temporal lobe structure that is posterior to the amygdala. The hippocampus is important to the process of encoding of episodic memories. Because the brain has bilaterally symmetry, there is a hippocampus in each cerebral hemisphere. If damage occurs to the hippocampus in only one hemisphere, the brain can retain almost normal memory functioning. If damage occurs to both hippocampi, it is very difficult for one to form new memories and often also affects memories formed before the damage. The hippocampi are critical in remembering processes and remembering how to do certain tasks. The hippocampi can be damaged during violent traumas such as combat and natural disasters, which are why individuals who endure combat or natural disasters, can be affected by PTSD (Eichenbaum. 2000). These three parts of the brain are activated with high intensity during trauma-related events, which are sometimes damaged creating the symptoms of PTSD. There is continuous debate about whether PTSD is a stress-induced fear disorder or an anxiety disorder. Shin and Handwerger (2009), came to the conclusion that though PTSD is caused by an anxiety of sorts, most of the effects come from the actual fear. They noted that PTSD shared functional abnormalities with borderline personality disorder. Paige (1997) wrote that PTSD was an anxiety disorder and should be diagnosed by the anxiety disorder strategies in The Diagnostic and Statistical Manual of the American Psychiatric Association (DSM). There has been more research conducted demonstrating that PTSD is a stress-induced fear versus an anxiety disorder.
Post-Traumatic Stress Disorder and the Emotional Stroop Effect Imagine a soldier coming home from war. Every night he has nightmares about bombings, shootings and hostages. He goes to the doctor and asks what is happening. The doctor diagnoses him with PTSD. How might the doctor diagnose the soldier, determine the intensity of the disorder and help him recover? The Stroop Effect is the answer. The emotional Stroop Effect can be modified to show interference to any disorder (Gotlib & McCann, 1987). Research shows that people exhibit a slowed reaction to color name emotionally relevant to their disorder. In the Color Stroop Task, there is more interference in naming the color then reading the actual word because of the color while in the Emotional Stroop Task; it is more difficult to name the color of the word because of the word itself (Gotlib, 1984; Cothran & Larsen, 2008). Because of the absence of PTSD experiments using the Emotional Stroop Test, Ashley, Honzel, Larsen, Justus, & Swick, (2013) administered an experiment to understand the exaggerated Emotional Stroop Effect in war veterans. The different types of words used in the test were: combat, matched-neutral, neutral, positive and negative. All PTSD victims had increased interference while reading the trauma-related section of the test almost 80% higher then the controls. Subjects that participated in the test revealed that they “could not take their eyes off the words.” (Ashely et al., 2013) While repeated the combat section of the test repeatedly, the interference began to drop at a steady level.
Conclusion
The Stroop Effect is a very helpful tool for diagnosing the intensity of and treating parts of Post-Traumatic Stress Disorder. By administering the Stroop test to a PTSD patient, one can learn how severe the disorder is by examining the time it takes for a subject to finish the test. If repeated with consistency, a PTSD patient will be able to eventually control emotional outbursts related to the trauma that caused the PTSD. In order to gain a complete understanding of the Stroop Effect’s true effect on PTSD, it is necessary to conduct an experiment that examines the long-term effect of PTSD treatment using the Stroop Effect.

References
Ashley, V., Honzel, N., Larsen, J., Justus, T., & Swick, D. (2013). Attentional bias for trauma-related words: Exaggerated emotional Stroop Effect in Afghanistan and Iraq war veterans with PTSD. BMC Psychiatry, 13(1), 1-11. doi:10.1186/1471-244X-13-86
Bohren, C. (2006). Fundamentals of atmospheric radiation: An introduction with 400 problems. (Wiley-VCH. p. 214). ISBN 3-527-40503.
Cothran, D., & Larsen, R. (2008). Comparison of inhibition in two timed reaction tasks: The color and emotion Stroop tasks. Journal of Psychology, 142(4), 373-385.
Davis, M., & Whalen, P. J. (2001). The amygdala: Vigilance and emotion. Molecular Psychiatry, 6. 13-34.
Eichenbaum, H. (2000). A cortical-hippocampal system for declarative memory. Nature Review Neuroscience, 1, 41-50.
Gotlib, I. H., & McCann, C. D. (1984). “Construct accessibility and Depression: An examination of cognitive and affective factors”. Journal of Personality and Social Psychology, 47 (2):, 427-439
Kline, L. W. (1921). An experimental study of associative inhibition. Journal of Experimental Psychology., , 4, 270-299.
Paige, S. R. (1997). Current perspectives on posttraumatic stress disorder: From the clinic and the laboratory. Integrative Physiological & Behavioral Science, 32, 5.
Stroop, J. R. (1935). Studies of interference in serial verbal reactions. Journal of Experimental Psychology, 18, 643-662.
Shin, L. M., & Handwerger, K. (2009). Is posttraumatic stress disorder a stress-induced fear circuitry disorder?. Journal Of Traumatic Stress, 22(5), 409-415.
Ury, H. L., van Reekum, C. M., Johnstone T., Kalin, N. H., Thurow, M. E., Schaefer, H. S., et al. (2006). Amygdala and ventromeial prefrontal cortex are inversely coupled during regulation of negative affect and predict the diurnal pattern of cortisol secretion among older adults. Journal of Neuroscience, 26, 4415-5525.
What is Post-Traumatic Stress Disorder (PTSD)? (n.d.). Retrieved from http://www.nimh.nih.gov/health/topics/post-traumatic-stress-diosrder-ptsd/index.shtml

Ashley, V., Honzel, N., Larsen, J., Justus, T., & Swick, D. (2013). Attentional bias for trauma-related words: exaggerated emotional Stroop Effect in Afghanistan and Iraq war veterans with PTSD. BMC Psychiatry, 13(1), 1-11. doi:10.1186/1471-244X-13-86 A psychiatric team in California studied an exaggerated emotional Stroop Effect in Afghanistan and Iraq war veterans. In their article, the team of scientists gave a modified emotional stroop test to thirty Afghanistan and Iraq war veterans with PTSD. The stroop test included 5 categories of words including: combat/trauma, matched neutral, positive, negative, and neutral. All PTSD veterans had considerably more interference on trauma-related words then the different controls that where tested. The study was limited by the availability of a wholly comparable control group. The article is extremely helpful. It creates a direct link between PTSD and the interference created by the Stroop Effect. The experiment took place less than a year ago making the data reliable because of how recently the study was done. The study is intended to be objective but is slightly biased do to the fact that the test subjects have varying intensities of PTSD. Though the study was biased, the authors of the source discovered that the Stroop Effect is directly related to PTSD and that the test can be used to assist in finding habituation effects, which can be diminished or confounded PTSD if trauma-related words are repeated. The article will most likely serve as my concluding body paragraph. It serves as a bridge between the Stroop Effect and PTSD while explaining how one influences the other. The source helped me understand both topics in more detail and helped me outline my argument. This article will be my last point discussed in the literature review as a closer to the idea of the Stroop Effect diagnosing and treating PTSD but will also act as an opener to the vast and unexplored topic.
Cothran, D., & Larsen, R. (2008). Comparison of Inhibition in Two Timed Reaction Tasks: The Color and Emotion Stroop Tasks. Journal Of Psychology, 142(4), 373-385. This article compares the two different stroop tasks, color and emotion. By administering both tests on normal people, the psychologists were able to tell how much interference came from which task, and if the interference came from the same part of the brain. The RT correlated across both tasks and there the traditional effects were found for each Stroop task. The authors suggest creating an experiment to test if people with disorders have an interference difference on both tasks. This article helps explain the fundamentals of the Emotional Stroop Task while proclaiming its reliability compared to the Color Stroop Task. This article helps explain the connection between the Stroop Effect and mental disorders like PTSD. The article proves that the interference from the Color Stroop Task and from the Emotional Stroop Task are the same making it a reliable source. This article compares the two tasks connecting how the two tests find the exact same thing. In the in my literature review, this article will conclude the Stroop Effect theme and begin explaining its relevance to mental disorders such as PTSD. My explanation of this article will serve as an opening argument as too why the Stroop Effect can be used to diagnose and treat PTSD. By being the closing argument to the first theme, this article will prepare readers for the upcoming section dealing with mental disorders such as PTSD. The simplicity of the topic hints at a wide range of possibilities to what the Stroop Effect could entail and what it can do. Therefore encouraging psychologists to toy with the idea of the Stroop Effect as a healing process, not just a law of inhibition.

Paige, S. R. (1997). Current perspectives on posttraumatic stress disorder: From the clinic and the laboratory. Integrative Physiological & Behavioral Science, 32(1), 5. This article examined which category of disorders should PTSD fit into.
The authors’ took into account the inhibition from Stroop effect related situations and the nature of the disorder. Unlike many other articles about PTSD the author’s decided to focus more on women and children who have experienced sexual trauma. The study concluded that though there where many similarities that PTSD shares with anxiety disorders, it is mostly a stress-induced fear disorder. Unlike most secondary articles, this article is objective in researching PTSD. There is no specific thesis they are trying to prove. On the contrary, their objective is to inform the world about PTSD and give their opinion about diagnosing and treating it. This article will be one of the subtopics in the PTSD theme because of its in-depth explanation of different components of PTSD. The article explains PTSD in places other then war, making it feel more personal and
connectible. In the literature review, this article will serve as a final argument about the importance of PTSD. Because the article explains more then just PTSD in war veterans, readers feel more passionate towards working towards a cure or treatment. Though a lot of content in a literature review is required to be factual and concrete, it is important to have an emotional piece that entices the audience to act on the issue you are writing about. This article does that for my topic by explaining how rape victims or natural disaster survivors are affected by PTSD and how many scientist overlook that fact while searching for a treatment.

What is Post-Traumatic Stress Disorder (PTSD)? (n.d.). Retrieved from http://www.nimh.nih.gov/health/topics/post-traumatic-stress-diosrder-ptsd/index.shtml This article, provided by the government, gives an overview of PTSD, including how it’s caused, what the symptoms are, who is at risk, and treatments. The article is intended for explaining PTSD in simple terms for public use. New patients can use this article to find out more about their disorder and learn how they are going to be treated. This is a great online source for PTSD patients and interested public. Because the government runs the website containing all this information, it would be safe to assume that it is updated regularly and the people maintaining the site did their research before posting it online. The U.S. Government is responsible for providing public services such as informative websites and lacking for doing so could result in a Supreme Court trial. The executive branch has a lot of incentive to keep websites like the National Institute of Mental Health up to date, factual, and informative. I will use facts from this article to introduce the topic of PTSD. It is important for readers to have background knowledge of the subject before going in depth about how the disorder occurs and what the disorder entails. Because it is at the beginning of the 2nd theme, it needs to be more factual then abstract like the Stroop Effect is. PTSD is a concrete disorder while the Stroop Effect is a psychological theory that can infinitely be expanded on.

Shin, L. M., & Handwerger, K. (2009). Is posttraumatic stress disorder a stress-induced fear circuitry disorder?. Journal Of Traumatic Stress, 22(5), 409-415.
This article examined which category of disorders should PTSD fit into. The authors’ took into account the inhibition from Stroop Effect related situations and the nature of the disorder. The authors’ proved their point by focusing on the parts of the brain that are affected and cause PTSD such as the amygdala, the medial prefrontal cortex, and the hippocampus. The study concluded that though there where many similarities that PTSD shares with anxiety disorders, it is mostly a stress-induced fear disorder. The authors’ arguments are supported by scientific facts about the brain system and by many case studies that explain what each part of the brain does. The authors’ perspective on the matter is prejudicial. They had an idea, wanted to prove it and so they found facts to back up their theory. Though the article is prejudicial, all the facts are proven and the authors simply connected the dots between the different ideas. This article will part of my explanation of PTSD. After giving a brief overview of the disorder, I will go in-depth about how the cause of PTSD and how one could possibly reverse the effects. This article is very factual and helps give my argument more concrete support rather abstract concepts provided by the Stroop Effect. By explaining this article in the literature review, I will give readers an understanding of what type of disorder PTSD is and allow them to see the connection of how the Stroop Effect could possibly help reverse the symptoms of the disorder.

Stroop, J. R. (1935). Studies of interference in serial verbal reactions. Journal of Experimental Psychology, 18, 643-662. This article explains the inhibition of every day tasks. It explains the theory of inhibition that states, “If a is already connected with b, then it is difficult to connect it with k, b gets in the way.” Two tests were created, a color naming and color reading test. More interference came from naming the color of a word. Because the color is already connected with a certain word, it is harder to connect that color with a different word because the original word gets in the way. The word stimulus has been associated with the specific response 'to read ', while the color stimulus has been associated wit various responses: 'to admire ', 'to reach for, ' 'to avoid, ' etc. slightly skewing the result. Though the data was skewed, the conclusion still remains provable. This Stroop Effect article is one of the most widely known and referred to articles about interference.
The author of the article was one of the top psychologists of his time and worked along many other famous psychologists to form some of the greatest psychological theories and concepts. This is an article about one of the two main topics discussed in the literature review while all other arguments branch off of the three major points. Stroop created the experiment with an objective approach having no idea what he would discover or if he would discover anything at all. Because of Stroop’s work, we understand the idea of interference in daily life. This article will serve as my first theme for the topic. It is important for readers to understand the Stroop Effect before I discuss PTSD because the interference explained by the Stroop Effect appears everywhere in the explanation of PTSD. By establishing the Stroop Effect as the first idea, I make it clear that it is the most important thing to understand in the paper. Through this establishment, I clarify the direction that the literature review is headed and what areas need more
study.