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Simulation Sickness and VR - What is it, and what can developers and players do to reduce it?
by Ben Lewis-Evans on 04/04/14 08:26:00 am   Expert Blogs   Featured Blogs

The following blog post, unless otherwise noted, was written by a member of Gamasutraís community.
The thoughts and opinions expressed are those of the writer and not Gamasutra or its parent company.


With the Oculus Rift and Project Morpheus somewhere on the horizon for consumers, and the work that Valve is doing, virtual reality (VR) is once again a hot issue for games with all the interest, hype, and business hypothesising that comes along with it.


One often mentioned issue with VR is that some people can feel sick when using it. Indeed, when Sony showed off the Morpheus at GDC this year they warned people if they started to feel sick to let the attendants know and stop playing. In academia this is often referred to as Simulator Sickness (or sometimes “Cybersickness”, if you want to go all Gibsonian).


Simulator sickness is a real problem for some people when using any simulator, although VR is particularly notorious, likely because of the sensory immersion, latency issues, and the added weight of a headset. Simulator sickness is also an issue that is of particular interest to me given my background working with driving simulators. As such, this article aims to lay out what the current science, that I am aware of, has to say about simulation sickness, what it is, why it occurs, and what developers and players can do about it.



What is it?


Simulation Sickness is a syndrome, which can result in eyestrain, headaches, problems standing up (postural instability), sweating, disorientation, vertigo, loss of colour to the skin, nausea, and - the most famous effect - vomiting. It is similar in effects to motion sickness, although technically a different thing. Simulation sickness can occur during simulator or VR equipment use and can sometimes persist for hours afterwards.


Furthermore, it is possible to use a simulator/VR set without simulation sickness only to get sick once you return to reality, particularly after extended use. Sailors called this “getting your land legs back” in relation to sea sickness, but perhaps we should take the cyberpunk approach and call it “Reality Sickness”. Also, people who use a simulator or VR for extended periods of time have been reported by some to have simulation sickness “flashbacks” later. Both of the above factors led the US military, according to some reports, to have a 24 hour ban on flight for any pilots after using a simulator.


One of the big issues with simulation sickness is that it is understudied (and some studies that exist are old, have questionable methodology, or rely on anecdotes), and that there is no universally agreed explanation for why it occurs. As such, the aforementioned ban by the US military may be an over-reaction or it may not.



Why does it occur?


There is no firm agreement on why, but there are a few theories. I will go briefly into them below, but if you are not interested in theorising, and just want to read tips on how to reduce simulator sickness, please do skip to the next section:


Cue Conflict Theory


This is probably the most dominant theory and simply put says that simulation sickness is caused by a mismatch between what we expect to see and feel and what we are actually seeing and feeling. Basically, this theory says that our body has an expected sensory input (based on past experiences and biology) and if that sensory input is different, for example you are running around in a VR first person game but in real life are sitting on your couch, we can experience simulation sickness.


The supporting evidence for this theory is:

  • People who are more experienced at an activity in reality are more likely to experience simulation sickness than novices. According to this theory this is because experts in the activity have a stronger/more sensitive sensory expectation and therefore virtual reality is more likely to provide the wrong input.
  • That adding motion to a simulation can help. However, it must be accurate otherwise it just adds even more to the sensory conflict. So, there is still an argument in the scientific community about the merit of adding movement to simulators in terms of a cost-benefit trade off.
  • That extended exposure can reduce symptoms. The argument being that you form new expectations related to the simulation - this then also explains possible sickness upon returning to reality where your expectations have changed.

Evidence against this theory:

  • It is a theory that has low reliable predictive value. In that it cannot be used to reliably predict who will or will not get motion sickness. Basically, people don’t get sick every time they experience different sensory input than they expect, just sometimes.
  • The theory doesn’t explain why sensory expectations not matching input would cause such an extreme reaction. Throwing up and falling over are not usually very evolutionary useful reactions, so why feel that way when the only issue is that your eyes say you are moving but the rest of your body says you are not?


Postural Instability Theory


The next theory is focused on the falling down and feeling dizzy part of simulation sickness and is promoted as an ecological theory that doesn’t rely on fluffy cognitive things like “expectations”. This theory says that our body is constantly making small adjustments to not fall over and relies on accurate sensory input to do so. When the sensory input is off the small adjustments also get thrown off resulting in simulator sickness.


Evidence for this theory:

  • Balance problems and dizziness can precede other simulation sickness symptoms.
  • Helps explain why simulation sickness goes away over time, basically your body adjusts. It also explains why people who are more experienced with a real life activity are more likely to get simulator sick (they have more to “train away”).

Evidence against:

  • Postural instability doesn’t always precede simulation sickness.
  • It, like cue conflict theory, has low predictive value.
  • Why does this lead to such an extreme “blllarrrhggghh” response?


Poison Theory


This theory mostly exists because of the last problem with conflict theory and postural instability theory in that the reaction to simulation sickness seems extreme. Poison Theory says that, evolutionarily speaking, one of the only times you will experience sensory input that is different than what you expect, or when you get all dizzy and have problems standing up, is when you have been poisoned. So what is evolutions best trick to get rid of poison? Be sick.


Evidence for this theory:

  • People get sick and fall down…

Evidence against this theory:

  • Low predictive value (notice a theme?). It is an evolutionary story that sounds good, but can’t really be reliably and accurately used to predict who will get sick under what conditions.
  • Why are young children resistant to simulation sickness? They are more vulnerable to toxins, so shouldn’t this defence be stronger?
  • Doesn’t stand by itself very well, so it is sometimes referenced just as an explanation for the pukey parts of the other two theories.


Other, lesser known, theories include:

  • Eye movement theory: Suggests that certain stimuli cause eye movements that create tension in the eye muscles which stimulate the vagus nerve leading to sickness.
  • Subjective vertical mismatch theory: An alteration of conflict theory that suggests the most important factor is the mismatch between a users sense of verticality vs the sensor input they are receiving about their verticality from the simulation.
  • Negative Reinforcement Model: Like Poison theory, this is an evolutionary theory that argues that movement that would generate sickness, or mismatched sensory information, suggests weakness or doing something that could make you weak. Therefore, to stop you doing it you get sick.



What developers can do to minimise simulation sickness


So, there is no agreement on exactly what causes simulation sickness, and indeed the theories overlap quite a bit, so the likely answer is a mixture of these ideas (plus probably some new ones). But despite not understanding what causes it there are some techniques that research suggests developers can do in games that may reduce its occurrence. Please note, these are only guidelines and may have varying levels of influence depending on the game, the hardware, and the person playing.


  • Maintain high frame rates and low latency: It isn’t just for game quality reasons that the folks at Oculus, Sony, and Valve have been stressing the need for low latency, responsiveness, and high frame rates. The low persistence tech Oculus is building into the Rift will help, but you still have to pull your weight. Basically, if there is lag between a player input and game output then the chance of simulation sickness increases. So, when it comes to VR if there is choice between better graphics vs low latency, the latency should win out. In terms of strict guidelines, it is hard to say. Some academics cite any latency above 46ms could start to get problematic, others cite 20ms, and indeed, Oculus targets under 20ms. Similarly, avoid motion blurring, which increases the sensation of movement.



A comparison of the low persistence offered by the new Oculus dev kit versus full persistence. Full persistence is much more likely to make you sick. 


  • Avoid flicker: Flicker and flashing should be avoided, particularly near the edges of vision, where it can be perceived by the brain as a signal for movement.


  • Make use of appropriate movement: Basically, match sensory expectations. So if the player is a human character, don’t use unrealistic movement (e.g. strafing) and tie camera movement to the head (i.e. it works like a turret, or… a head…). This includes taking advantage of head tracking when offered. Particularly inappropriate movement that should be avoided includes rapid tilting, rolling, and sinusoidal movement (e.g. up and down, or left and right, wave like movement, particularly at frequencies between 0.05 and 0.8 Hz). One example of these types of movement in games could be certain types of head bob or going up and down stairs - both of which can be troublesome in VR. Another example could be gun sway that fills a significant amount of the player’s vision and could create the illusion of left to right swaying motion.

An example of headbob that could be problematic in VR (This GIF was generated from this video, which is simply a engine demo and is not showing a VR game)

  • Limit uncontrolled movement: Related to above, basically if movement is happening without player control, particularly tilting, spinning, or flipping movement, then you are on your way to a vomit comet simulator. This idea of the advantages of being in control is similar to how drivers are less likely to get motion sick than passengers. Examples of uncontrolled movement could be as simple as a death animation where the character ragdolls or falls to the ground, tilting and shaking the camera, or a zoom transition between scenes.


  • Think about your camera height: The closer a camera is to the ground, the more the ground fills a player's vision and the faster what they are seeing on the ground will change. This increases the sensation of movement.

A proximity flying wingsuit simulator may be out of the question for those who are vulnerable to simulation sickness. Although, the folks who made Aaaaaaaaa! for the Rift, a base jumping game where surfaces do wizz by, say their game has overcome simulation sickness problems.

  • Limit movement through a scene: This is not to say remove control (see above) but rather use a fixed position where the player just has turret-like control of the camera. This of course limits game design, so it is a trade off.


  • Limit rapid changes in acceleration (including deceleration) and rapid shifts of perspective: This speaks for itself. But interestingly this also has an application when zooming vision, say with a scope on a gun in a game. Not only could it be a bad idea to have a majority of the screen rapidly zooming in or out, but being zoomed in can also increase the sensory input discrepancy. This is because when you are zoomed in your cone of vision moves faster than expected. To try this out yourself look through binoculars and then try moving around, it can get sickening quickly.  Also avoid to sudden death transitions or rewinding/fast forwarding time.


  • Use the world to support the players sensory system: If a player looks down, show them an avatar body and if you have a camera then player body tracking could help with this too, assuming it is responsive. If the player is flying a spaceship, place them in a cockpit with controls. Basically try and create a logical world that the players can focus on and anchor themselves in. If possible, UI elements should also be anchored into this world, rather than floating around in front of players. This also refers to creating an environment with a clear stable horizon, with stable reference points that players can focus on, rather than a world with a listing, uneven, or moving background.


  • Create an unexperienced experience: A bit weird to be suggesting this after saying to use the world to support the player, but as mentioned when talking about cue conflict theory, people who are experienced in a real world activity tend to be more likely to get simulator sick when that activity is simulated. Therefore, if you use VR for an abstract puzzler that has nothing to do with reality, or putting a player in a spaceship cockpit rather than having them walking around (walking being something we are all familiar with, flying less so), then it is possible that this may lessen the chance of simulator sickness..


  • Limit player field of view: Field of view seems to be related to simulator sickness because the lower the field of view, the lower the amount of stimulation in edges of the visual system and therefore the lower the feeling of movement. A lower than 30 degrees field of view has been suggested by some academics as dramatically reducing simulation sickness. The big downside of limiting field of view is that it is strongly related to immersion and presence, which are very important not only in games but also to VR specifically. But, field of view can be limited for in-game reasons such as being in a cockpit looking out windows.

Eve Valkyrie is an example of how a cockpit may be able to somewhat break up the field of view and place the player in a supportive environment.


  • Playtest: Hopefully playtesting your games is an obvious step in development, however, it is also important if you want to minimise simulation sickness. Another important point, which has been made well by Oculus, is to playtest with people who are unfamiliar with VR, as familiarity with a device can reduce simulation sickness. So, as a developer of a VR game yourself be aware that you make a poor playtester.


  • Support Short Play Sessions: The longer someone who is prone to simulator sickness plays, the more likely they may get sick. Furthermore, if someone starts getting sick and abandons your game they may want to come back later and try again. So, support short play sessions if possible, either via plentiful checkpoints or a save anywhere system.


  • Seek out experts: Oculus, Sony, and Valve have people much smarter (and prettier) than me working for them. They are running their own experiments, reading all the literature, and giving talks about what works and what does not. Seek them out, stay a while, and listen. Indeed, in the final stage of preparing this post I found that Oculus has a significant simulation sickness section of their best practice guide, which provides much of the same advice that I have. This not only shows that they are clued up on the literature, and that my googling skills need some work, but also that if we can both reach the same conclusions independently, then that is a good sign that this advice could be worth listening to.



What players can do to minimise simulations sickness


While developers and the VR companies have the most capability to prevent and reduce simulation sickness, there are a few things players who suffer simulation sickness can do to potentially help.


  • Be young: If you happen to be young, then good news! You’re more resistant to simulation sickness. Interestingly, some of the literature suggests that older people may be resistant too, however, I think this is just a result of poor application of old motion sickness data. Rather, within the simulation community it is (anecdotally) known that working with older adults means be prepared for a lot of participant loss due to simulation sickness.


  • Play in moderation: I know this makes me sound like a nagging parent, but remember, even if you don’t get simulator sick there’s a chance that after long exposure to VR you may get sick or feel dizzy/weird after returning to reality. This may not happen of course, but be aware that it is a possibility and try not to play for extended time before immediately driving a car or operating heavy machinery.


  • Play in a well ventilated, temperature regulated, safe space: Pretty self explanatory. Most of the symptoms of simulation sickness are aggravated by poor air and uncomfortable temperatures (particularly heat). As for safe, well this won’t help reduce simulator sickness but if you are going to get dizzy and potentially fall over then better make sure that your glass table/grandparent isn’t nearby.


  • Play when healthy: If you are feeling sick already, hungover, or particularly drunk/on certain drugs then jumping into a VR experience may not be the way to go.


  • Calibrate your device: If the VR device needs calibration, make sure it is done and done well (applies to Devs too! Support calibration, remind players about it).


  • Try to act natural: Don’t hold yourself rigid (although, see below about being supported), go with the movements of the game (if safe), do what feels natural even if it makes you look silly. If the game has you seated, then sit. Avoid rapidly and unnecessarily shaking your head around.


  • Focus on stable objects on the horizon: Assuming they have been provided it can be helpful if you start to feel sick that you focus on a stable object near the horizon in the game. This is a trick used by dancers to avoid getting dizzy when spinning, and by sufferers of motion sickness, and can have some success for simulator sickness too.


  • Try again: For most people repeated exposure to a VR experience will reduce or remove simulator sickness. This does not mean just tough it out or use the VR equipment for long periods despite feeling sick. Rather, use it for a little while, then stop if you start feeling sick, then wait for a day or so (but not more than a week), and then try again. Take it easy. Unfortunately, this kind of adaptation may be game or hardware specific and it is also estimated that up to 5% of the population may be particularly prone to simulation sickness and unable to adapt (Bles & Wertheim, 2000). If this estimate is true, perhaps we end up with another cyberpunk trope - the sim sick underclass who can never join the VR future - but perhaps advancements in VR can lower or remove this figure completely.


  • Be stable: If postural instability theory is right, then sitting in a stable, supported position, or even lying down should help as your body won’t have to work to maintain postural stability. However, this may induce more discrepancy between the movement in the game and movement in real life, so it may be useful for a limited number of games and hardware setups.


Lying down to play may, in some cases, help reduce simulation sickness (photo credit Kotaku)


  • Research the games you are going to play: Does it look like it has a lot of bouncing rolling movement? Rapid accelerations and decelerations? Poor latency and frame rate? Is there a lot of uncontrolled movement? Then maybe if you are concerned about simulation sickness this game isn’t for you.


  • Don’t expect to be sick: Easier said than done, especially after reading a long article telling you all about what the symptoms are and what causes them. However, some element of simulation sickness is due to the nocebo effect - i.e. if you are cued about the fact you may get sick, and expect to get sick, you may be more likely to be sick. This is not saying it’s the fault of  those who get simulator sick, but rather to say try and relax, and don’t stress out.

Finally, if you happen to get simulator sick, please be careful. Give yourself time to recover and do not do any activities afterward that involve you having to show motor control or maintain your balance. Don’t operate heavy machinery or a vehicle for a while after getting sim sick. Just in case.


However, hopefully developers and VR hardware companies will succeed in creating simulation sickness free experiences that mean that players don’t need any of the above advice!



Additional Reading


Below is a list of some of the academic reports I used in putting together this article. Sadly not all of them are open access and available to the public, but many of the summary articles are (e.g. Bles & Wertheim; Johnson; Kolasinski etal; & Mollenhauser).




















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Kim Pallister
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Good post!

It's worth noting that in addition to the factors that cause simulation sickness, there are other factors that have to do with HMDs that can cause other symptoms that can further aggravate simulation sickness.

An obvious example is simulation latency. Bad enough that the simulation may not match what you expect to feel, motion-wise. Worst still if the resultant display camera position/angle is further from expectation because of sluggish performance). The Oculus folk and others seem to be talking a lot about how to reduce this as best possible

Another example is disparity between accomodation(focus), and focal point convergence. While less of an issue than latency, this disparity is far more amplified in HMDs than it is for stereo TVs or movie theaters.

I'm glad to see folk trying to ground everyone's understanding of these problems so the industry can work on minimizing them.

Ben Lewis-Evans
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Hi Kim,

Thanks for the comment. I am glad you enjoyed the post. I do mention latency, but you are right that it is a very important issue and also one that Oculus has been rightly very vocal and active about. As for accommodation and convergence, you are again correct that this is one of the issues related to simulation sickness that is worse for HMD's. Since that is a hardware issue that developers and players can't do too much about I left it out for space reasons, but yeah it is an issue for sure.

Matthew Wilson
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I see Everyone say to not strafe or walk backwards with the rift, and maybe for most people that would ring true, but I think for some it might be fine. Usually the argument is that it is an unnatural motion as people don't move like that in real life, but all four years of high school I did, in marching band. You would have to walk backwards and sideways at sometimes very fast pace while keeping your shoulders and head parallel to the front of the field. So basically strafing and moving backwards. Such actions even now feel natural because of how much I did them.

Miguel Rafael
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Tried oculus twice and got sick. Read through this great article to learn more about why. I was very sceptical about Vr especially cause I get sick in 3d films but the experience was really immersive and worth the half hour of light sickness.

Hope in the future I can enjoy Vr longer and who knows, maybe even do a game with it.

Dustin Chertoff
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You do build resilience to sim sickness the more you interact with HMDs. But you have to go in short bursts. 5 minutes, then rest. Once you are safe there, go for 10 minutes. And so on. Once you learn your time threshold, you'll know the kind of play session length you can put up with.

Ideally, devs will cater to 5-10 minute play segments giving people the option to break at regular intervals.

Maarten Brouwer
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Good to think about these things; I can imagine VR devs that don't have any sickness problems can easily underestimate the problem (I fear I'm one of those 5% as VR demos that do all these things quite well still have me throwing off the headset after a few minutes; let's hope the better tech of later versions really matter in this regard)

One additional thing that I noticed: the olfactory sense may also play a role. When I put on the Rift, the smell of it immediately seems to have an effect on my stomach. Don't know if it's a direct influence or that I associate it with getting sick in earlier instances, but I heard someone else saying, after getting sick within the first minute of a demo, that the smell of the headset reminded her of a car in which she often had problems with motion sickness.

Ben Lewis-Evans
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Yeah, I think you are right when you mention that the olfactory component could be a conditioned response. We are evolved to form strong responses to stimuli that makes us feel sick - particularly if there is an olfactory or taste component as these senses are connected to food (it is very important that you work out what food makes you sick or not).

Christopher Landry
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In regards to Field of View: The recommendation seems intolerably low to me, especially since there are known cases of Simulator sickness with people sitting in front of their TV or computer monitor playing normal video games with low Field of View. These people seem to have issues, including most or all of the ones listed above, with anything below 90 degrees. However, give them 110-120 degrees and the issues go away.

Knowing this to be the case, and knowing that a human's normal, expected Field of View in Reality is closer to 180 degrees (up to 270 degrees with eye movement), I would assume that having a realistic Field of View (150-180 degrees) would be far better to combat simulator sickness than narrowing the Field of View down to nearly a pinhole.

In fact, cutting the Field of View down to a 1/5th of Reality's Field of View would be similar to the example you gave above with walking around while looking through binoculars, which you pointed out would cause Simulator Sickness in most people.

I understand that would mean a vastly different tech than the standard flat screens, but flexible LCD screens already exist, so this shouldn't be completely unattainable.

Ben Lewis-Evans
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The very low FOV reported, is the recommendation from academic articles as the FOV that is least likely to produce simulation sickness. It isn't the best way to combat it, but you have to remember that the wider the FOV the more likely that you generate a sense of motion (because as you say it is more realistic and therefore there is more simulation at the edges of vision, which is sensitive to motion cues), and it is this illusory sense of motion that seems to be related to simulation sickness. That said, the FOV issues may be able to be overcome with good handles on the other issues (latency in particular)

It isn't like the binocular example, because that isn't because of a limited FOV but rather that due to the zoom on binoculars your vision will be moving faster than matches with how much it usually should when you move your head.

Karl E
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Great post. How about input though? Is it possible, by making possible more natural interactions with objects, to make the player feel more "anchored" in the world and less prone to sickness?

Ben Lewis-Evans
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I am not sure. Perhaps? But, anecdotally, I have heard with driving simulators that sometimes as they get closer to reality with moving bases and such, the symptoms actually get worse. The suggestion being that the more real it seems, then the more likely that even small mistakes in sensory input can trigger sickness (because we expect the sensory input to match more closely when it is more real). At least that is a cue theory explanation, and thus the suggestion that perhaps experiences that don't match expectations and are unreal (but don't involve uncontrolled motion) may be less likely to cause simulation sickness.

Mike Griffin
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It would be interesting to have a racing wheel, shifters and pedals implicitly designed for VR. The steering wheel could contain simple sensors along its periphery that detect where the person's hands are placed on the wheel in real-time, displaying the result for the player.

You couldn't simulate a hand moving from the wheel to a stick shift. If the physical stick shift had a sensor, the person's hand would 'pop' from the wheel to the stick in a disconcerting way.

You could probably get away with it if the steering wheel had F1-style shifters just behind the wheel, again with sensors to match real-life hand position to in-game hand position. That's a very small transition.

Or just make it a pedal-based shift, and don't worry about foot sensors for the pedals as players are highly unlikely to gaze at their racer's feet for any length of time in the cockpit, and matching foot-to-pedal motion is relatively simply regardless.

Anyway, I foresee some very interesting input devices may arrive should VR seriously take off, as developers and players may decide it's simply not enough to play certain game types with Move controllers, DualShocks, or even sophisticated VR-friendly devices like the Razer Hydra.

Some very exciting possibilities.

ps: A tangible, physical, handheld input device will probably be essential to VR regardless. I don't see a purely skeletal/motion-based solution (i.e. Kinect) as a sufficient "anchor" for simulating physical interaction in a VR world. A camera + held input devices probably gets the job done, without destroying your living room. A couple of wireless power gloves and 'clip on' light nodes for your body might also do the trick, but likely only for standing-up VR experiences.

David Navarro
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"The suggestion being that the more real it seems, then the more likely that even small mistakes in sensory input can trigger sickness"

It's the Uncanny Valley of simulation...

Jon Rimmer
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Very interesting article, thanks!

Your conclusions about the predictive power of the poison theory seem a little pessimistic though. If we hypothesise that some simulator sickness is a result of learned connections between poisoning and its symptoms that is not inborn, but occurs within a person's lifetime, then not only would we expect children to suffer less, as they would have less learned poison responses, but we would also expect that people whose lifestyle and medical history indicates they have been exposed to less poisons should also suffer less. The most obvious thing to look at would be alcohol abstention. Has any study been done to see if people who are lifelong non-drinkers suffer any less from simulator sickness than the general population?

Ben Lewis-Evans
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As far as I am aware poison theory is an evolutionary theory, not a conditioned learning theory. It argues that we have an inbuilt "feel sick" reaction to when our sensory inputs are mixed up as in our evolutionary history the only time that would happen is when poisoned.

What you outline is much more in line with the ideas behind the Negative Reinforcement Model, which is kind of an extension to/built off poison theory.

However, children do still get simulation sick, and motion sick, it is just that young kids seems particularly resistant. So it can't just be experience with poisons and their sensory impacts that cause the symptoms.

Jon Rimmer
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Well, my understanding of things like taste aversion[1] are that while they have an evolutionary basis, they still require a trigger event to create the link between the stimulus and the nausea response, after which the effect is virtually permanent. Normally, the stimulus is a taste, but perhaps the accompanying sensory weirdness is remembered as well, but we don't notice so much because the normally the only thing that recreates it is re-ingesting the same poison, or doing unusual physical activity.

Also, poisons might not be the only way to create such a link. Possibly common early-childhood illnesses tend to create a similar link between sensory weirdness and nausea, the exact nature of which might depend on the symptoms experienced?


Ben Lewis-Evans
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Taste aversion is indeed strong, although does tend to be related to the sense of smell or taste rather than vision. But it is possible. Also, this is a conditioned response. The sickness (related or unrelated) must be experienced and associated with the taste for it to occur. So, yes it does have some evolutionary basis in that our bodies are strongly selective towards forming an association between a taste and sickness. But I think this is more in line with the negative reinforcement model than directly with the poison model.

Again, as far as I can tell poison theory leans more towards saying that the stimuli (incompatible sensory input) itself is what is causing the symptoms due to inbuilt biological triggers without having to rely on previous conditioned responses. So, this is much more of a direct line between stimuli and sickness due to the nature of the stimulus itself. Some would even argue that this makes more sense from an evolutionary, since reactions to poison are better if they are immediate, without having to learn, as you may not get a second chance - but that could be leaning a bit too much in the direction of an optimal design fallacy ;)

I do still feel that, at the moment, poison theory is a bit too much of a "just so" story. It relies on the fact that some people sometimes feel sick in these situations and then works backwards to make an educated guess at an evolutionary reason. However, this means it does not have strong predictive power as people don't always get simulation sick when experiencing mismatching sensory input (indeed many people take drugs to get this effect for fun). It is a nice theory though, and has good face validity, but like the others it doesn't necessarily stand well on its own at the moment. Perhaps as more research is done though?

Interestingly, conflict theory would have no problem with a suggestion of learning - in that their explanation for why particularly young children are resistant is that they haven't built up expectations yet.

Anton Knyazyev
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I think children have less dramatic response to things not feeling 'right' simply because they don't have a very stable idea of what 'right' is yet. People are supposed to be adaptable to different environments (within a certain range), and children are still going through that adaptation. As for the predictive power, I guess some people are more cautious/protective, and some are more adventurous. The most obvious test groups representing these tendencies are women and men (respectively), wasn't there a recent study that confirmed that women have more difficulties with VR?

Ben Lewis-Evans
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Anton, your line of reasoning, is what is forward by cue conflict theory. Which is the dominant theory. So it fits for sure :)

As for the question of women and simulation sickness, it is possible there might be a difference but it is still very much an open question. Some of the literature does suggest that women are more likely to get simulation sickness. But there is not much research on this in general and there are methodological issues that need to be overcome in terms of separating nature and nurture enough to be sure.

For example, it is a well known confound in society at the moment that males are less likely to report feeling "weak" than females. Which could mean that males just report feeling simulator sick at lower frequencies than females, but are still experiencing it.

I have personally seen guys turning white, driving very slowly, and showing poor lane control in a driving simulator but upon being asked if they were ok would insist there was nothing wrong.

Another confound is that simulator sickness reduces with exposure to the technology. So if males in our society are spending more time immersed in first person games, and other experiences that may be related to simulator use, they may already have more resistance.

But even with these confounds aside, just simply more research needs to be carried out! It should be an interesting time.

Anton Knyazyev
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More precisely, by a "recent study" I meant this:
I'm pretty sure it's more than a psychological issue of trying to appear more 'manly' by not admitting feeling uncomfortable (though it's obviously a factor as well)

Ben Lewis-Evans
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Yeah, I guessed that was the one you were referring to :) But as she says in the article

"However, I never did go back to the clinic to find out. The problem with this type of research is that youíre never really sure of your findings until they can be reproduced. A lot more work is needed to understand what I saw in those experiments. Itís quite possible that I wasnít accounting for other variables that could explain the differences I was seeing"

The data just isn't clear enough on the gender issue yet :)

Gary LaRochelle
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Interesting article on Motion Sickness and the treatment of it:

Not that I am endorsing anything. I am sure there are some people out there that would be willing to help study this treatment.

From the article:
"Motion sickness due to Virtual Reality
Motion sickness due to virtual reality is very similar to simulation sickness and motion sickness due to films. In virtual reality, however, the effect, made more acute, as all external reference points are blocked from vision, the simulated images are 3-dimensional and in some cases stereo sound that may give a sense of motion. The world's most advanced simulator, the NADS-1, located at the National Advanced Driving Simulator is capable of accurately stimulating the vestibular system with a 360-degree horizontal field of view and 16 degree of freedom motion base. Studies have shown that exposure to rotational motions in a virtual environment can cause significant increases in nausea and other symptoms of motion sickness."

"An antiemetic is a drug that is effective against vomiting and nausea. Antiemetics are typically used to treat motion sickness
Drs West and Lockhart have also created Canavert, a cannabis based treatment for motion sickness."

Brendan Gallagher
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Gotta love a technology that leaves a decent portion of it's potential user base grabbing for a barf bag. Just don't see the attraction.

Jon Rimmer
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It's a technology that can give the user the ability to instantly transport themselves to any place, real, imagined, or even impossible, and engage in any activity, without risk of injury or death, as easily as we now switch on a TV, and you can't see the attraction because the current prototypes make people barf?

Nobody's saying simulator sickness isn't a problem, or that it won't need to be fixed for VR to gain mainstream traction, but not being able to understand why people are excited in spite of that demonstrates a stunning lack of imagination.

Brendan Gallagher
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I'm sure some folk love it. It has value to them. I'm not poo pooing love of VR for anyone who gets excited by it. Just not my cup of soup.

VR first made a public debut in Shopping malls in the 80s, it was primitive but cool... A lot of folk got sick as they stumbled away. It went away. I just think it will go away again. But good luck to those who champion it.

TC Weidner
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so ship travel and airplane travel makes no sense to you either, since they both leave a portion of their users reaching for the barf bag??

Brendan Gallagher
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Ahh, but I can get a drink on an airplane and a full breakfast buffet on board a ship. Well worth the lean over the rail.

On a serious note, Wii in people's homes was considered futuristic, getting up and moving while you play. Kinect was another level... get up, move around, your body is the control. Still in the right direction. It's social it's physical. It makes sense in the home. VR may make sense to hardcore gamer types who are lucky enough not to vomit, but broad appeal? VR died in the 80s, I can't see the consumer market embracing it any faster in the 21st century. But time will tell.

Brandon Van Every
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"Oculus, Sony, and Valve have people much smarter (and prettier) than me working for them." Prettier than you? I bet you weren't talking about boy toys. In the interest of reducing sexism in the game industry in general, and to keep the intellectual rigor of any given subject on track, how about you just can it about how people look when writing your articles. Thanks.

Ben Lewis-Evans
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That comment was aimed at all genders. In fact it is a self-deprecating joke aimed at my own looks. It is a common joke to make in New Zealand (where I am from) where we are quite into self-deprecation (

However, I apologize if it was interpreted differently.