Nowadays, experiencing shocking and dangerous situations in which you think yours or someone else’s life is in danger is not rare. People who are exposed to, or have witnessed life-threatening circumstances, may develop post-traumatic stress disorder (PTSD). PTSD is a mental health condition that manifests in re-experiencing a traumatic event through nightmares and flashbacks, often resulting in the avoidance of trauma-associated cues, negative changes in mood, and a state of increased alertness (also called hyperarousal). In the long-term, this condition can have a significant impact on someone’s day-to-day life and their ability to concentrate at work. According to the National Center for PTSD, 6 out of every 10 men and 5 out of every 10 women experience at least one traumatic event in their lifetime, and about 8% of the adult population is expected to develop PTSD at some point in their lives.
‘Intrusive memories can make a person feel like they are re-experiencing a traumatic event, even in the absence of any stimulus.’
After a traumatic event, people can re-live the situation over and over again through memories. These memories, called intrusive memories, are considered a core clinical symptom of PTSD. Unlike other types of memories, intrusive memories can make the person feel like they are re-experiencing the traumatic event even in the absence of any stimulus. Thus, they can occur at any time, popping up into one’s mind without warning and can include sensory impressions of the trauma (sounds, visual images, and smells) causing physical changes like heart racing and sweating. For example, after suffering a car accident, a person may report intrusive images of seeing “smoke” and hearing the “bang” of the airbags. As reliving a trauma is emotionally distressing, finding ways to reduce the occurrence of those memories may help relieve post-traumatic suffering in people affected by PTSD.
What if we could reduce the occurrence of intrusive memories using a brief and simple intervention like a computer game? A little more than 10 years ago, a first-of-its-kind study showed that playing Tetris reduces the frequency of involuntary memories from a traumatic film. In this study, Holmes and colleagues (2009) asked participants to watch an emotionally disturbing film, consisting of scenes of real injury and death. After a break, a brief reminder of the film was shown, followed either by playing Tetris or sitting quietly for 10 minutes. Over the following week, subjects who had played Tetris reported fewer involuntary memories from the film than subjects who did not. Could this indicate that playing Tetris attenuates the occurrence of intrusive memories? In order to understand how Tetris had such an effect, we need to first understand how the authors came up with this idea.
“Could this indicate that playing Tetris attenuates the occurrence of intrusive memories?”
The authors based the study on two key findings from the fields of neurobiology of memory and cognitive science. Studies on memory consolidation (the process by which recently learned experiences are transformed into long-term memories) show that a 6-hour window exists for the formation of memories, during which different manipulations can interfere with this process. In cognitive science, studies on working memory (a set of processes that allow us to manipulate and store temporary information) show it has limitations in its capacity. Thus, when we perform two tasks that simultaneously tax working memory, there is a competition for shared resources, which can lead to one task interfering with the other. Based on these findings, the authors of the aforementioned study hypothesized that playing Tetris a few minutes after viewing the distressing film would impede the consolidation of memories from it. The interference effect on memory would be achieved by taxing working memory, as subjects were first shown images from the film (and perhaps held these images in mind) and then were immediately asked to play Tetris, a well-known visually demanding game. As both tasks tax visual resources of working memory, the authors expected that competition for these resources would take place, leading to one task interfering with the other.
‘The authors of the study hypothesized that playing Tetris a few minutes after viewing the distressing film would impede the consolidation of memories from it – The interference effect’
In follow-up studies, researchers investigated if playing Tetris would also reduce the occurrence of involuntary memories from a traumatic film once they are already consolidated. This time, the idea for this type of study came from another key finding connected to the field of the neurobiology of memory. After a consolidated memory is recalled, there is a window during which the memory can be modified (Nader et al., 2000; Monfils et a., 2009). For this memory to persist, it must go through a process known as reconsolidation, which turns the memory stable again. Thus, to assess if Tetris would have any effect on consolidated memories, participants were asked to watch a traumatic film on a given day, before being exposed to scenes from the movie one to three days later, followed by playing Tetris or not playing it. Over the following week, participants reported the number of their intrusive memories. In one study (James et al., 2015), participants who had played Tetris after viewing scenes from the film reported fewer intrusive memories than those who either did nothing or did one thing separate from the other (just played Tetris or just watched the scenes). In another study (Kessler et al., 2020), participants who played Tetris after viewing scenes from the film also reported fewer intrusive memories than those who either only viewed the scenes or viewed the scenes and played a non-visual game (a quiz game). Although playing Tetris was the most effective intervention, subjects who viewed the scenes followed by a quiz game also had fewer intrusive memories than those who only viewed the scenes. This effect may indicate that tasks that use working memory may reduce intrusive memories by a general taxation of working memory rather than a modality-specific taxation (in which both tasks share some components for one to interfere with the other). Yet, this hypothesis needs further investigation. Additionally, it is worth mentioning that even though Tetris-exposed volunteers reported less intrusive memories, they were able to identify scenes from the traumatic film, suggesting that their recognition memory (the ability to recognize previously encountered events, objects, or people) was intact.
“This effect may indicate that tasks that use working memory may reduce intrusive memories by a general taxation of working memory”
The findings discussed so far show that a Tetris-based intervention reduces intrusive memories using a traumatic film that simulates a traumatic situation. Whilst exciting, these studies did not investigate if playing Tetris could have the same effect in people who underwent an actual trauma. To investigate whether playing Tetris would be beneficial or not in a real-world situation, Iyadurai and colleagues (2018) invited A&E patients in the UK to participate in a similar type of study within 6 hours after their accident (that is, during the consolidation window of memory susceptibility). For this study, participants were either allocated to receive standard care (control group) or to receive standard care and play Tetris after recalling the accident (Tetris-exposed group). On the following week, subjects who played Tetris reported fewer intrusive memories and less distress induced by intrusion symptoms.
Even though these findings are promising, some questions remain. We still do not know if these effects would be long-lasting and could be detected several months after the intervention. As all findings were reported from small groups of participants, insights from larger groups are still warranted. Nonetheless, a behavioral-based approach like this opens up a promising avenue of research that might, ultimately, lead to more accessible and simple approaches to tackle intrusive memories in PTSD.
Has gaming ever helped you to cope with any distressing events? It would be great to hear your experiences in the comments below.
Interested in more PTSD content, or want to know how the fear response works? Take a look at this article featuring one daring archeologist.
— Written by Mariella Careaga. Illustrated by Sumana Shrestha.
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Iyadurai, L., Blackwell, S. E., Meiser-Stedman, R., Watson, P. C., Bonsall, M. B., Geddes, J. R., … & Holmes, E. A. (2018). Preventing intrusive memories after trauma via a brief intervention involving Tetris computer game play in the emergency department: a proof-of-concept randomized controlled trial. Molecular psychiatry, 23(3), 674-682.
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Kessler, H., Schmidt, A. C., James, E. L., Blackwell, S. E., von Rauchhaupt, M., Harren, K., … & Axmacher, N. (2020). Visuospatial computer game play after memory reminder delivered three days after a traumatic film reduces the number of intrusive memories of the experimental trauma. Journal of Behavior Therapy and Experimental Psychiatry, 67, 101454.
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National Center for PTSD. (n.d.). How common is PTSD in Adults? Retrieved from: https://www.ptsd.va.gov/understand/common/common_adults.asp