Bright and fast-moving particles of colours that appear and disappear with booming sounds like fireworks easily captivate our senses.

Have you ever noticed that after playing video games, you continue to experience sensations related to the game even when you’re not playing? Video game playing seems to enhance our senses and cognition not only while playing but also after playing. For example, when closing our eyes, at every blink of the eyes or even with open eyes, colours, textures, pixelations, hyperactive or still images arise. Aural and other sensations do not escape the mind; music, sounds, voices, kinaesthetic and tactile sensations come back to us, at least temporarily. Slips of the tongue intrude conversations, spontaneous movements of limbs, and behaviours sneak into everyday routines. These are “echoes of video game playing”, which I have called in my research Game Transfer Phenomena (GTP).

Some have referred to GTP as “consensual hallucinations” and “the original AR”. These phenomena are fascinating but not mystical, and are not exclusive to video game playing! That being said, playing video games can enhance these phenomena. It’s all due to a combination of factors such as prolonged exposure to sensory stimuli, trance states (losing track of time, immersion, sense of presence), engaging in high cognitive load processes, and emotional engagement1.

Beyond the scientific exhilaration, one of the main goals of my research on GTP has been to explain and inform about GTP, to avoid GTP being interpreted as a sign of psychopathology by gamers or others.  Certainly, re-experiencing images and sounds frequently or for prolonged periods of time can be extremely upsetting to the degree of suffering from it. However, in the majority of situations, this does not meet the criteria for a diagnosis. My hope is to destigmatize hallucinatory phenomena, improve our understanding of these phenomena, and help those who actually suffer from them.

I understand seeing images with closed/open eyes with game content as pseudo-hallucinations, images with perceptual properties manifest as visual sensations where there is no loss of sense of reality. However, in my studies, I have found that for some gamers, seeing images and hearing sounds can lead to short moments of dissociation when they lose touch with reality and interact with the images. Seeing images from video games can happen when we’re in a relaxed, half-asleep state, but it can also happen when we’re fully awake and something in our environment triggers a memory or association with the game.

What is GTP telling us about the human mind? Can we use GTP to our advantage? What challenges does GTP pose?

The recently launched Tetris Effect game touched the heart of my area of research expertise, GTP, so I needed to stop and reflect!

The astonishing game Tetris Effect is a new “incarnation” of the famous game Tetris. The name Tetris Effect is inspired by re-experiencing images and thoughts from the game after playing. The origin of the term “Tetris Effect” is a bit uncertain, but it is documented back in 1994.2

I’m excited because the video game industry is openly paying attention to a “real-world phenomenon where players’ brains are so engrossed that images of the iconic falling Tetrimino blocks (i.e. the Tetris playing pieces) linger in their vision, thoughts, and even dreams…” as the Tetris Effect website states. I have been consumed with a strong passion for this phenomenon for the past seven years. It has been my life’s work to understand it, and I have moved from country to country in search of support for my research. Despite my pursuits’ capricious nature, I believe it is indispensable to understand these fascinating phenomenon.

Is the marketing campaign of Tetris Effect marks a turning point in recognizing that video games can produce hallucinatory-like phenomena after exposure? As VR devices and mixed-reality technologies are affordable to more consumers, this may be the future state of mind.

Just the simple Augmented Reality technology used in Pokémon Go in one of my studies shows that 15% of the gamers had the sensation that a Pokémon was physically present, and another 16% had found themselves looking for Pokémon outside the screen while playing (N=1,313).8

Trailer of the game:

Documentary about the game that complemented Tetris Effect launch:

The enhancement and the alteration of the human senses have been around for ages, and technology has only added to this trend. To me, this seems like a turn in history, a push toward a positive acceptance of hallucinations. It’s interesting to note that hallucinations were once seen as having cultural significance. However, as time passed, they were given a medical context and were considered a pathological condition.

Here, I enumerate examples of how hallucinatory phenomena and the word “hallucinations”, a previously hushed word, is starting to enter the technological realm.

    • Applications developed to alter our perception. There are those that induce optical illusions and synaesthesia, like SoundSelf. And then there are binaural beats that can modify states of consciousness and mood, like i-doser.
    • Expectations for 2027: Mar Gonzalez Franco, a researcher at Microsoft predicted “by 2027 we will have ubiquitous virtual reality systems that will provide such rich multisensory experiences that will be capable of producing hallucinations which blend or alter perceived reality. Using this technology, humans will retrain, recalibrate and improve their perceptual systems. In contrast to current virtual reality systems that only stimulate visual and auditory senses, in the future, the experience will expand to other sensory modalities including tactile with haptic devices.”3
    • The video game Hellblade portrays a female warrior who struggles with symptoms of psychosis (hallucinations and delusions). The Hellblade team was even awarded “psychiatric communicator of the year”.
  • Projects on special sensory effects, such as “Programmable Synthetic Hallucinations” led by Dan Novy as part of his PhD at the MIT, which “will allow hallucinatory phenomena to be programmed and utilized for information display and narrative storytelling” (During my recent visit to Boston, I was curious to find out more. Unfortunately, I couldn’t make it to the tea time that Dan kindly invited me to. I hope we can catch up in the future).

Some relevant findings on GTP, at this point:

  • GTP is common among gamers, almost independent of what game they play; even gamers of Pokémon Go have reported it. 81-97% of gamers have experienced at least one instance of GTP (N>6,000; 15-60 years old)5-8.
  • Some of the most common forms of GTP are visualizing/seeing images with closed eyes (74-77%) and hearing background music (71-74%). 5-6
  • Seeing images with open eyes has been reported by 29-31%. 5-6
  • Some gamers reported seeing images everywhere, sometimes for days 13.
  • In most cases, GTP is experienced while doing everyday chores and is, in many cases triggered by game-related cues 5.
  • GTP has also been reported while trying to fall asleep 5 and under hypnagogic states documented in experimental studies (hypnagogic hallucinations are one of the most common types of hallucinations among the non-clinical population14.)
  • Recalling dreams and dreaming about video games are strongly connected with GTP. 9
  • According to a study with over 2,000 participants, most gamers do not report negative consequences and GTP is more likely to be experienced as pleasurable than unpleasurable. One in five wants that GTP happens again 5.
  • Positive appraisal of GTP increased the probability of experiencing GTP. 9
  • A total of 20% reported distress/dysfunction 5, especially those who experienced several forms of GTP and very frequently (58%). 9
  • Some gamers reported confusion, annoyance and sleep deprivation, some to the degree that they stopped playing. 13
  • The automatic nature and intrusiveness of GTP can pose challenges in our everyday lives (e.g., be distracting, leading to an attentional bias toward game-related stimuli and absence of awareness of one’s own actions). 14

While it’s important to be mindful of the potential drawbacks of GTP for certain individuals, I think there is a lot of potential for using it in therapeutic interventions. As I argue in my recent paper in  Pervasive Computing Paradigms for Mental Health: “First insights into applying the Game Transfer Phenomena framework for positive means10.

In 2016, my colleague Professor Mark D. Griffiths and I argued that “playing Tetris is not only an effective visuospatial task (overloading working memory resources needed for imagery-formation while playing), but as demonstrated in GTP studies, video game content stays active after playing (e.g., mental imagery, sensory perceptions), and may offer additional benefits for managing unwanted intrusions.” 4

However, as far as I’m aware, the studies where playing Tetris has been effective in interfering with distressful imagery and cravings, the participants played the game for a very short time, and there are no reports of the participants experiencing GTP or not. This is something I’m interested to find out more about.

In “The Happiness Advantage,” Dr. Shawn Achor talks about the Tetris Effect and how it can help identify negative behaviours and promote positive thinking. He encourages rehearsing positive thoughts to overcome narrow-minded perspectives. However, he also acknowledges that the Tetris Effect can be maladaptive in certain situations.

Here are some comments by gamers who have played Tetris Effect and experienced GTP:

“I shut my eyes an see blocks. I’m continuously replaying the songs in my head. Because of Tetris Effect, I now know what digital euphoria seems like” (Admin).

“Im having hallucinations…the sofa’s going away from meeee”! GF, after an extended session of Tetris Effect” (John Ricciardi, Twitter).

“I have been playing Tetris Effect, which is great. I’ve played an hour or two every night since it came out on Friday, but I’m going to have to stop because I’m literally suffering from the Tetris Effect at night. I have sleep problems as it is, and I have been waking in the middle of the night, and every time I try to sleep, I am slipping into a half-dream state, but imagining playing Tetris. It’s kind of comparable to when you work a long shift and then dream you’re still at work, but it has definitely messed with my sleep. Has anyone else literally felt ”the effect” ?” (God_Of_Phwoar)

Another gamer reported the opposite:

“What’s bizarre is that I tend to get the afterimage stuff extremely quickly… But not at all from this version.” (Strings)

I initially documented the phenomena in my master thesis in 2010 and called it Game Transfer Phenomenon (GTP)11, later published in a scientific journal in 201112. As mentioned before, over the seven years that have passed, I have dedicated the most of my academic career since then to further investigate GTP, supported by my dear mentors and enthusiastic collaborators, jumping from country to country; Sweden, UK, Belgium and not sure where to next.

I hope this initiative of the video game industry and the recent portrayal of GTP in popular media and scholarly books will inspire more researchers, developers and students to take GTP into their own hands. Despite the significant amount of evidence we have gathered on the topic, there are still more questions than answers regarding the various forms of manifestation and related factors that requires further investigation.

If you experience some GTP with the Tetris Effect game, please share.

I have just started playing Tetris Effect. My favourite levels so far are “Ritual Passion” and “Spirit Canyon”. They are brilliant! Powerful beats, movements, near-misses. Loving it!

I have experienced GTP in different games, so let’s see what happens with Tetris Effect.

If you want a copy of my papers, the validated scale to measure GTP, have some questions, or want to start a project that involves GTP, just drop me an email.

Read more:

    1. Ortiz de Gortari, A. B., & Griffiths, M. D. (2017). Beyond the Boundaries of the Game: The Interplay Between In-Game Phenomena, Structural Characteristics of Video Games, and Game Transfer Phenomena In J. Gackenbach & J. Bown (Eds.), Boundaries of Self and Reality Online (pp. 97-121). San Diego: Academic Press.
    1. Goldsmith, J. (1994). This is your brain on Tetris. Wired, 2012.
    1. Microsoft. (2016). 17 for ’17: Microsoft researchers on what to expect in 2017 and 2027, from
    1. Ortiz de Gortari, A. B. O., & Griffiths, M. D. (2016c). Commentary: Playing the computer game tetris prior to viewing traumatic film material and subsequent intrusive memories: examining proactive interference. Frontiers in Psychology, 7, 260.
    1. Ortiz de Gortari, A. B., & Griffiths, M. D. (2016b). Prevalence and characteristics of Game Transfer Phenomena: A descriptive survey study. International Journal of Human-Computer Interaction, 32(6), 470-480.
    1. Dindar, M., & Ortiz de Gortari, A. B. (2017). Turkish Validation of the Game Transfer Phenomena Scale (GTPS): Measuring altered perceptions, automatic mental processes and actions and behaviours associated with playing video games. Telematics and Informatics, 34(8), 1802-1813.
    1. 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(18), 588-594.
    1. Ortiz de Gortari, A. B. (2017a). An empirical study on Game Transfer Phenomena in a location-based augmented reality game. Telematics and Informatics, 35(2), 382-396.
    1. Ortiz de Gortari, A. B., & Griffiths, M. (2016a). Severity levels of Game Transfer Phenomena: Associated factors and impact. Journal of Behavioral Addictions, 5(S1), 16-17.
    1. Ortiz de Gortari, A. B. (2018). First insights into applying the Game Transfer Phenomena framework for positive means. In P. Cipresso, S. Serino, Y. Ostrovsky & J. T. Baker (Eds.), Pervasive Computing Paradigms for Mental Health (Vol. 253). Boston: Springer.
    1. Ortiz de Gortari, A. B. (2010). Targeting the Real life Impact of Virtual interactions: The Game Transfer Phenomenon. 42 video games players’ experiences. Master’s degree in Human Rights and the Best Interest of the Child Empirical research, Stockholm University, Stockholm.
    1. 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.
    1. Ortiz de Gortari, A. B., & Griffiths, M.D. (2014). Altered visual perception in Game Transfer Phenomena: An empirical self-report study. International Journal of Human-Computer Interaction, 30(2), 95-105.
  1. Ohayon, M. M. (2000). Prevalence of hallucinations and their pathological associations in the general population. Psychiatry Research, 97(2–3), 153-164.