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Blocking out the pain: Tetris, trauma, and Game Transfer Phenomena

Unwanted visual intrusions are characteristic of Post-Traumatic Stress Disorder (PTSD). According to Dr. Emily Holmes and her colleagues in a 2009 paper in the journal PLoS ONE, one innovative intervention for inhibiting unwanted intrusions is playing the Tetris videogame, described as a ‘cognitive vaccine’ in preventing intrusions after traumatic events. Playing Tetris consumes heavy visuospatial working memory resources that potentially compete with cognitive resources required for elaboration of visual imagery. Since Holmes and colleagues’ study, other studies have used Tetris to inhibit intrusive imagery including more studies by Holmes and her colleagues and others by Ella James’ research group, as well as some innovative studies using Tetris to reduce drug cravings by Jessica Storka-Brown and her colleagues (see ‘Further reading’ below). However, none of these studies assessed the role of videogame content after playing in relation to Game Transfer Phenomena (GTP), an area that we have carried out a lot of research into (see ‘Further reading’ below).


GTP research has investigated non-volitional experiences (e.g., altered sensorial perceptions and automatic mental processes/behaviours) mostly experienced after gaming. Gamers often report sensorial (visual/auditory) intrusions after playing (e.g., visual and auditory imagery, hallucinations). In a survey of 2,362 gamers that we published in a 2016 issue of the International Journal of Human-Computer Interaction, most (77%) had visualized images from a variety of videogames (including tile-puzzle games) with closed-eyes, and one-third (31%) had visualized images with open-eyes. Other studies have experimentally induced videogame-related visualizations at sleep onset (including studies by Stickgold and colleagues [2000], Wamsley and colleagues [2010], Kusse and colleagues [2012] – see ‘Further reading’).

James and colleagues’ 2015 study in the journal Psychological Science was the first to make explicit reference to GTP (referred to as the ‘Tetris effect’ [TE]). In 2012, we argued the TE term is misleading as it suggests repetition is the core of transfer effects. However, other factors are involved. Research concerning GTP makes the distinction between sensorial modalities facilitating non-volitional phenomena with videogame content that occur along the continuum from mild to severe. Moreover, the descriptive constructs of GTP are empirically based on our analysis of 3,500+ gamers and have been examined via confirmatory factor analysis demonstrating good reliability and validity.

James and her colleagues tested if playing Tetris offered a protective mechanism against re-experiencing traumatic events. Healthy participants (n=56) were randomly assigned to either playing Tetris for 11 minutes, or doing nothing before exposure to a 12-minute traumatic film. Image-base memories about the film were then registered in a one-week dairy. However, playing Tetris as a proactive interference task before watching the film did not show significant results. James and colleagues offered different explanations including: (i) duration of the task in relation to film length, (ii) temporal contingencies between the tasks, (iii) differences between the task types, (iv) videogame types used, and (v) reactivation of gameplay during the film for aided interference. In a commentary paper published in a 2016 issue of Frontiers in Psychology, we discussed these findings and some of its shortcomings in relation to GTP literature.

  • Duration of task in relation to film length: Playing Tetris for 11 minutes may not have been long enough to compete with the consolidation of memory of the 12-minute film. GTP are significantly more likely to occur when playing 3-6 hours. Our research reported only 4% of gamers reported GTP when playing sessions shorter than one-hour. Laboratory experiments have taken days of playing to induce game-related visualizations at sleep onset.
  • Temporal contingencies between gaming and film watching: The tasks were performed minutes apart from each other. GTP mostly occur soon after stopping playing but our research has found that gamers have also reported GTP days after playing. In most cases, duration of experience is very short (seconds/minutes) but in some cases hours or longer.
  • Differences between the tasks: Previous studies have demonstrated that similar tasks aid interference. However, watching a film is a passive activity while gaming is interactive requiring additional perceptual/motor skills. Therefore, it may be expected that gaming is more potent as interference task, particularly because inducing the subjective sense of presence in the virtual world may strengthen the interference.
  • Type of videogame used as interference task and emotional content of film: The unrealistic (geometric) Tetris content may have been overwritten by the film’s traumatic images. Visualization of stereotypical games induced at sleep onset are characterized by lack of emotion, assuming that the amygdala and the reward system are not involved. In GTP research, emotions in tile-matching puzzle-games are incomparable to emotions in realistic videogames.
  • Reactivation of gameplay during the film for aided interference: The use of cue reminders may have potential in reviving videogame content. In many cases, thoughts and altered perceptions are triggered by game-related cues. Selective attention toward game-related cues has been demonstrated in experiments. GTP have been reported in variety of videogame genres particularly those that have very realistic graphics and settings. Therefore, more realistic games may aid associations between real life stimuli and videogame content, and may be more effective in competing with memories of traumatic events.

In our Frontiers paper, we noted that playing Tetris is not only an effective visuospatial task (overloading working memory resources needed for imagery-formation while playing), but as demonstrated in our GTP studies, videogame content stays active after playing (e.g., mental imagery, sensory perceptions), and may offer additional benefits for managing unwanted intrusions. GTP may potentially strengthen effects of interference tasks but should be used cautiously, because videogame content not only targets unwanted intrusions, but also influences individual cognitions, perceptions, and behaviours in day-to-day contexts (e.g., attention bias, lack of task awareness, control inhibition failures). Moreover, our studies have shown distress and dysfunction have been reported with GTP.

Consequently, further research needs conducting to identify: (i) videogames that are most effective, (ii) playing duration, (iii) factors that reduce intervention efficacy and strategies to control them, and (iv) individuals that may benefit the most from such intervention. While using videogames as intervention tools for preventing unwanted imagery from traumatic experiences has potential, therapeutically it is still at an early stage.

  • (Please note: This blog was co-written with Dr. Angelica Ortiz de Gortari and is based on an article we published in Frontiers in Psychology: Ortiz de Gortari, A.B. & Griffiths, M.D. (2016). Playing the computer game Tetris prior to viewing traumatic film material and subsequent intrusive memories: Examining proactive interference. Frontiers in Psychology, 7, 260. doi: 10.3389/fpsyg.2016.00260)

Dr. Mark Griffiths, Professor of Behavioural Addiction, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading

Holmes, E. A., James, E. L., Kilford, E. J., & Deeprose, C. (2010). Key steps in developing a cognitive vaccine against traumatic flashbacks: Visuospatial Tetris versus Verbal Pub Quiz. PloS ONE, 5(11), e13706.

James, E. L., Bonsall, M. B., Hoppitt, L., Tunbridge, E. M., Geddes, J. R., Milton, A. L., & Holmes, E. A. (2015a). Computer game play reduces intrusive memories of experimental trauma via reconsolidation-update mechanisms. Psychological Science. doi: 10.1177/0956797615583071

James, E. L., Zhu, A. L., Tickle, H., Horsch, A., & Holmes, E. A. (2015b). Playing the computer game Tetris prior to viewing traumatic film material and subsequent intrusive memories: Examining proactive interference. Journal of Behavior Therapy and Experimental Psychiatry. doi: 10.1016/j.jbtep.2015.11.004

Kusse, C., Shaffii-Le Bourdiec, A., Schrouff, J., Matarazzo, L., & Maquet, P. (2012). Experience-dependent induction of hypnagogic images during daytime naps: A combined behavioural and EEG study. Journal of Sleep Research, 21(1), 10-20.

Ortiz de Gortari, A. B., Aronsson, K., & Griffiths, M. D. (2011). Game Transfer Phenomena in video game playing: A qualitative interview study. International Journal of Cyber Behavior, Psychology and Learning 1(3), 15-33.

Ortiz de Gortari, A. B., & Griffiths, M. D. (2012). An introduction to Game Transfer Phenomena in video game playing. In J. I. Gackenbach (Ed.), Video Game Play and Consciousness (pp. 223-250). Hauppauge, NY: Nova Publisher.

Ortiz de Gortari, A. B., & Griffiths, M. D. (2014a). Altered visual perception in Game Transfer Phenomena: An empirical self-report study. International Journal of Human-Computer Interaction, 30(2), 95-105.

Ortiz de Gortari, A. B., & Griffiths, M. D. (2014b). Auditory experiences in Game Transfer Phenomena: An empirical self-report study. International Journal of Cyber Behavior, Psychology and Learning 4(1), 59-75.

Ortiz de Gortari, A. B., & Griffiths, M. D. (2014c). Automatic mental processes, automatic actions and behaviours in Game Transfer Phenomena: An empirical self-report study using online forum data. International Journal of Mental Health and Addiction, 12(4), 1-21.

Ortiz de Gortari, A. B., & Griffiths, M. D. (2015a). Game Transfer Phenomena and its associated factors: An exploratory empirical online survey study. Computers in Human Behavior, 51, 195-202.

Ortiz de Gortari, A.B. & Griffiths, M.D. (2016). Prevalence and characteristics of Game Transfer Phenomena: A descriptive survey study. International Journal of Human-Computer Interaction, 32, 470-480.

Ortiz de Gortari, A.B., Oldfield, B. & Griffiths, M.D. (2016). An empirical examination of factors associated with Game Transfer Phenomena severity. Computers in Human Behavior, 64, 274-284.

Ortiz de Gortari, A. B., Pontes, H. M. & Griffiths, M. D.  (2015). The Game Transfer Phenomena Scale: An instrument for investigating the nonvolitional effects of video game playing. Cyberpsychology, Behavior, and Social Networking 10, 588-594

Skorka-Brown, J., Andrade, J., & May, J. (2014). Playing ‘Tetris’ reduces the strength, frequency and vividness of naturally occurring cravings. Appetite, 76 , 161-165.

Skorka-Brown, J., Andrade, J., Whalley, B., & May, J. (2015). Playing Tetris decreases drug and other cravings in real world settings. Addictive Behaviors, 51, 165-170.

Stickgold, R., Malia, A., Maguire, D., Roddenberry, D., & O’Connor, M. (2000). Replaying the Game: Hypnagogic images in normals and amnesics. Science, 290(5490), 350-353.

Wamsley, E. J., Perry, K., Djonlagic, I., Reaven, L. B., & Stickgold, R. (2010). Cognitive replay of visuomotor learning at sleep onset: Temporal dynamics and relationship to task performance. Sleep, 1(33), 59-68.


Playing with fire: A brief and personal look at ‘survivor guilt’

Football. Love it or hate but you cannot ignore it. For many people, football is a central part of their lives (mine included). That is one of the reasons I carried out research on football fanaticism because I believe there is a tiny minority of fans that are addicted to the football teams they follow (see my previous blog on ‘fanorexia’ for an overview).

Apart from a four-year period in my life (more of which later), football has always been an important part of my leisure time. Like many children I was brought up on a healthy diet of football. In the 1970s, my dad and brother were staunch Liverpool fans (as they were both born there) but I was a Sunderland supporter (and still am). I have supported Sunderland ever since I was six years old when I watched them beat Leeds 1-0 in the 1973 FA Cup final. This was certainly the first match I remember watching and for years after I had lots of flashbacks of seeing captain Bobby Kerr lifting the trophy and manager Bob Stokoe’s run across Wembley at the final whistle.

Despite my almost religious love of football as a child, I didn’t go to a single live football match simply because my family couldn’t afford it. I grew up in Loughborough so the nearest football teams were Leicester City, Nottingham Forest, Notts County and Derby County. My parents couldn’t even afford to travel to the games let alone watch one (and we never had a car until I reached my later teens). At the time (in the 1970s and early 1980s) I could still get my weekly fix of soccer action on Match of the Day (on BBC1) and the Star Soccer match (on ITV).

Throughout my formative years I not only watched football but also played it a lot too. In my junior school I shared the captaincy with one of my best friends at the time but on getting to secondary school I discovered I wasn’t as good as I thought (I only ever managed a regular slot in the second elevens; first team call up only ever came if there were lots of injuries). I devoured football. I used to be one of those very sad individuals who could not only tell you the score of every Wembley cup final since 1923 but could also name all the scorers. This came to great effect when I was 14 and my class at school (3L4 – so called because the class was the third year at secondary school and our form tutor’s room was ‘Laboratory 4’) won the Question of Sport team prize (mostly thinks to my sad but encyclopaedic knowledge of all things sporting). This passion stayed with me until I was 18 years old.

The first live football that I started watching regularly was Bradford City. As a first year undergraduate at the University of Bradford I got a student discount to go and situate myself in the Midland Road Stand at City’s home ground Valley Parade. That was 1985. The year that Bradford went up as the Third Division champions with ex-Leeds United legend Trevor Cherry as manager. After Sunderland, Bradford City became my ‘second team’. The last game of the season was against Lincoln City and it was billed as a ‘celebration’ game as Bradford City were already the Division winners. It was May 11th, I had just finished all my end-of-year university exams, and I was in great spirits. As usual, I attended the match with my best friend Geoff Harvey (now a well respected author of books on both football fans and sports betting). As it was a celebratory occasion we also managed to convince two of our female friends to join us (neither of them had ever been to a live football match before that day).

The day turned out to be a day I will never forget. As the game kicked off, little did we know that 45 minutes later the whole of one of the stands would be up in flames – ‘The Bradford Fire’. For those reading this who have no idea what I am talking about, here is the relevant information (from Wikipedia):

“The Bradford City stadium fire was the worst fire disaster in the history of English football. It occurred during a league match in front of record numbers of spectators, on Saturday, 11 May 1985, killing 56 and injuring at least 265. The Valley Parade stadium, long-established home to Bradford City Football Club had been noted for its antiquated design and facilities, including the wooden roof of the main stand. Warnings had also been given about a major build-up of litter just below the seats. The stand had been officially condemned and was due for demolition. The match against Lincoln City had started in a celebration atmosphere, with the home-team receiving the Football league Third Division trophy trophy. At 3.40 pm, a small fire was reported by TV commentator John Helm, but in less than four minutes, in windy conditions, it had engulfed the whole stand, trapping some people in their seats. In the panic that ensued, fleeing crowds had to break down locked exits to escape. There were, however, many cases of heroism, with more than fifty people receiving police awards or commendations”.

Thankfully, I was in the Midland Road stand (directly opposite to where the fire started). The one thing I still remember to this day was the intense heat inside the stadium. I have never experienced anything like it in my life. Everyone’s faces around me were bright red from the heat of the fire. None of us particularly like to think about death, but I have always thought that the two ways I wouldn’t want to die would be to either burn to death or to drown. As we left the stadium and made our way back to the Halls of Residence (about a 45-minute walk) I grateful to be alive. I knew I would have to ring my parents to let them know I was alright (as they knew I was going to the game). As this was in the era before mobile phones, another memory I have was the long queues outside all the telephone boxes as people wanted to let their loved ones know they were safe. I didn’t manage to get through to my Mum until about 6.15pm. Even by this time, the first deaths had been recorded. It was mid-evening that the horror of the day started to sink in and the next morning as all the Sunday papers’ front pages were about the 50+ deaths.

Over the next few months, I ruminated a lot about the deaths that day. At the end of July 1985, I took a walk to the Valley Parade stadium and broke down in uncontrollable tears. That was the first time I had cried about the tragic events of May 11. When the new season started, I lost all interest in football. I didn’t watch a full match for the next four years. Whenever I thought about football, I thought about the Bradford fire and had flashbacks. In December 1985, I began a long-term relationship with a woman who’s grandad had been burned in the fire. It was around that time that I found out that one of the technicians in our Psychology department (who I had become friendly with) had lost his father in the fire. Although I could go hours without thinking about the fire, when I thought about it I felt psychologocally uneasy. It was hard to put into words. It was much later that I came across the concept of ‘survivor guilt’. The Wikipedia entry notes:

“Survivor guilt (or survivor’s guilt; also called survivor syndrome or survivor’s syndrome) is a mental condition that occurs when a person perceives themselves to have done wrong by surviving a traumatic event when others did not. It may be found among survivors of combat, natural disasters, epidemics among the friends and family of those who have committed suicide, and in non-mortal situations such as among those whose colleagues are laid off. The experience and manifestation of survivor’s guilt will depend on an individual’s psychological profile. When the Diagnostic and Statistical Manual of Mental Disorders IV (DSM-IV) was published, survivor guilt was removed as a recognized specific diagnosis, and redefined as a significant symptom of post-traumatic stress disorder (PTSD)”.

Although this description does not totally match the symptoms and thoughts I had, I do think (in retrospect) I had a mild from of ‘survivor guilt’. I also think that what I suffered was a mild form of PTSD given that PTSD refers to a group of symptoms, such as disturbing recurring flashbacks, avoidance or numbing of memories of the event, and hyperarousal, continue for more than a month after the occurrence of a traumatic event” (Wikipedia). Thankfully, the cliché that ‘time is a great healer’ is true in my case. During the end of my PhD at the University of Exeter (1989), I began to watch football again and was a regular at St. James Park for Exeter City’s home games. My love of football returned and I began to think less and less about the Bradford Fire.

This is the first time I have ever written this down fully and is a good example of what I would describe as ‘therapeutic writing’ (something I have occasionally written about – see my previous blog on diary writing). I hope that you will forgive me for the lack of empirical data in this particular blog but just writing this all down has helped me feel better about one of the most heartfelt days of my life. Normal service will be resumed next time.

Dr. Mark Griffiths, Professor of Gambling Studies, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading

Wikipedia (2014). Bradford City stadium fire. Located at:

Wikipedia (2014). Post-traumatic stress disorder. Located at:

Wikipedia (2014). Survivor guilt. Located at:

Norse power: A brief look at Berserker rage

Ever since I was a young kid, I have used the word ‘beserk’ (to describe someone going into a mad, wild, uncontrolled and violent rage) in my day-to-day language. However, it wasn’t until I was in my teens when I bought the Gary Numan albums The Fury and Beserker that I came to realize the origin of the word.

Beserker rage is a culture-bound condition historically affecting Norsemen. The condition manifested itself among males only as an intense fury and rage (berserkergang, i.e., “going beserk”) and mostly occurred in battle situations (but could also occur when they were engaged in labour-intensive work). Dating back as far as the ninth century, the berserker Norse Warriors were alleged to be able to perform almost seemingly impossible super-human feats of strength. Nowadays, the word ‘berserker’ refers to anyone that fearlessly fights with a disregard to their own lives. Similar conditions have been noted in other cultures. For instance, the Irishman Cúchulainn (“Culann’s Hound”) was recorded as displaying ‘battle frenzy’ and ‘foaming at the mouth’ akin to berserkers in texts such as The Tain. The Malay phenomenon of ‘running amok’ (i.e., running mad with rage) also appears to bear a close resemblance to berserkers.

Those displaying beserker behaviour were also said to experience a specific set of symptoms prior to the rage (i.e., beginning with shivering and chattering of their teeth, followed by a swelling and changing of colour in the face as they literally became ‘hot-headed’. The final stage was full-blown rage and fury accompanied by noisy grunts and howls. They would then just indiscriminately injure, maim and kill anything in their path. This would be followed by one or two days of feebleness, along with a dulling of the mind. The condition of berserkergang was described in the thirteenth century by Icelandic poet Snorri Sturluson:

“[Odin’s] men rushed forwards without armour, were as mad as dogs or wolves, bit their shields, and were strong as bears or wild oxen, and killed people at a blow, but neither fire nor iron told upon them. This was called Berserkergang”.

The ravenous self-induced rage before battle commenced enabled the Norsemen to indiscriminately ‘loot, plunder and kill’. 
A recent book about the Vikings claimed that some battle chiefs held their berserkers “in reserve” during a battle. The berserkers were only sent into fight if one section began to weaken. An article on berserkers in the Journal of World History by Dr. M. Speidel noted that Norse berserkers were very effective killers, but could not stop killing at will. Apparently, their berserker state was only turned off once all members of the opposition were dead. László Kürti, in a 2004 encyclopedia entry on shamanism claimed that berserker is a regional form of present-day shamanism that utilizes archaic Nordic techniques – particularly the ability to go into a trance-like state.

Various theories about the causes of the condition have been speculated. Some have alleged that psychoactive drugs (such as hallucinogenic agaric mushrooms or copious alcohol drinking) were used. Some botanists claim that berserker behavior can be caused by the ingestion of the plant bog myrtle, one of the main spices in Scandinavian alcoholic beverages. Other theories speculate either pre-existing genetic and/or medical conditions or pre-existing psychological disorders (e.g., mental illness, manic depression [i.e., bipolar disorder], epilepsy). Some have even speculated that the fury may just be a consequence of post-traumatic stress. For instance, clinical psychiatrist Dr. Jonathan Shay wrote in his 1994 book Achilles in Vietnam:

“If a soldier survives the berserk state, it imparts emotional deadness and vulnerability to explosive rage to his psychology and permanent hyperarousal to his physiology –  hallmarks of post-traumatic stress disorder in combat veterans. My clinical experience with Vietnam combat veterans prompts me to place the berserk state at the heart of their most severe psychological and psychophysiological injuries”

Professor Jesse L. Byock claimed in a 1995 issue of Scientific American, that berserker rage could perhaps have been a symptom of Paget’s Disease (i.e., uncontrolled skull bone growth that often causes painful pressure in the head). However, there doesn’t seem to be any conclusive evidence of this.

Other more esoteric theories surround spiritual and/or supernatural beliefs. For instance, some scholars have claimed that the Vikings believed in spirit possession and that berserkers were possessed by the animal spirits of wolves and/or bears. According to some theorists, berserkers learned to cultivate the ability to allow animal spirits to take over their body during a fight (an example of animal totemism) that also involved drinking the blood of the animal that they wished to be possessed by.

Back in 1987, Dr. Armando Simon published a paper in the journal Psychological Reports and argued that berserker rage (or as he termed it ‘Blind Rage Syndrome’) should be incorporated into the Diagnostic and Statistical Manual of Mental Disorders. Dr. Simon characterized the condition as (i) violent overreaction to physical, verbal, or visual insult, (ii) amnesia during the actual period of violence, (iii) abnormally great strength, and (iv) specifically target oriented violence. Some case studies are presented and a parallel is made with the Viking Berserkers of the Middle Ages. Dr. Simon also claimed that the condition had typically been diagnosed as part of other violent disorders (such as intermittent explosive disorder). However, it looks unlikely that berserkers will be making a separate entry into the DSM anytime soon.

Dr Mark Griffiths, Professor of Gambling Studies, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK

Further reading

Armando, S. (1987) the berserker/blind rage syndrome as a potentially new diagnostic category for the DSM-III. Psychological Reports, 60, 131-135.

Kürti, L. (2004). Shamanism – Neo (Eastern Europe). Located at:

Nationmaster (2012). Berserker. Located at:

Shay, J. (1994). Achilles in Vietnam. New York: Scribner.

Simon, A. (1987). The berserker/blind rage syndrome as a potentially new diagnostic category for the DSM-III. Psychological Reports, 60, 131-135.

Speidel, M. (2002). Berserks: A history of Indo-European ‘mad warriors’. Journal of World History 13, 253-290.

Wikipedia (2012). Berserker. Located at: