Brains in Vats and Virtual Reality on Steroids

In the (reasonably near) future, humans have developed the field of medicine significantly, and we now have the technology to isolate the brain in a vat of oxygenated fluid. Assume the process of doing so is safe, although irreversible, and that a machine facilitates all body functions - providing nutrients, circulating blood and fluid, and the nasty one - providing stimulus as best it can.

In most cases, the transfer from body to vat is voluntary. Some people will choose to have their brains placed into new bodies, while others will have supercomputers simulate life for them - providing electrical input as if the situations the isolated brain is encountering are real.

However, sometimes these transfers take place without the knowledge, and thus consent, of the participant. Perhaps the government is particularly evil, and has the money to sedate the person - the next time they wake up, they will assume things are normal, when in fact they may be in a simulation or a new body. Let's focus on the simulation aspect of this scenario.

The resulting problem

When someone voluntarily chooses to enter a simulation in this way, they will understand that the world is not real. That means it's 'ok' if some things are a little off - if they don't feel quite as tall, or if it's harder to breathe, or if their vision is better - they will know it's a simulation, and that's expected.

When someone is transferred involuntarily, they may realize there's a problem when not everything around them is exact - and that may reveal the true nature of what happened. For example,

Jessica is $f$ feet tall, with shade $s$ skin, weight $h$ hair, and predisposed conditions that change things no one else can tell by looking at her $p$, $r$, and $e$

When Jessica is transferred, she does not feel $f$ feet tall, her skin is shade $q$, her hair is too light, and she doesn't have conditions $p$ and $r$. She knows something's up because she's heard these stories before, and she knows the associated symptoms.

The illusion is broken, and Jessica freaks the **** out.

It is impossible to exactly reproduce the sensations any person receives with a machine in this way!

My thoughts

One might argue that this scenario is analogous to dreaming - you can proceed through a dream while being ignorant that everything around you isn't real. Perhaps there's a way to make Jessica ignore aspects of herself, while still functioning inside the simulation, so she doesn't realize the problem. I'm thinking something kind of like how in The Sixth Sense,

The psychiatrist has been dead since the opening scene in which he was shot, but he has been ignorant to the signs that he's a ghost and continues to try to interact with the world as normal

The question

Short of a lobotomy, is there a way to induce ignorance (kind of like a dream) that allows the individual to function without realizing the nature of their reality?

When answering this
is not expected but acceptable
would be great but may not be possible
or pseudoscience is fine, but not ideal

  • $\begingroup$ The related question is "what makes you believe you currently understand the nature of your reality?" How do you know this hasn't already happened to you? A few hundred years ago people knew the signs of being possessed by a demon, but now we know this sort of possession does not occur. Knowledge is a tricky beast. $\endgroup$
    – Cort Ammon
    Dec 5, 2016 at 0:33

3 Answers 3



Also known as Sodium Amytal or more commonly called truth serum. Amobarbital has some interesting side effects with how it messes with the mind, which could prove useful. While under the effects of Amobarbital the higher level cognitive abilities of the brain are impaired. This can result in brain not being capable of realizing that it has become a brain in a jar (the dream feeling). Amobarbital can also make the brain suggestible and even result in false memories. This can be used to try and convince the brain of a lie that can serve as a cover for why things do not add up.

An example of a cover is that they had experienced a stroke that impacted the sensory processing centers of their brain and so everything is going to seem different and the prognosis is grim that they will fully recover from it. For this scenario the brain should wake up in a hospital and go through a process of rehab to recover from said stroke. This will give the person who orchestrated it a chance to improve the calibrations, which the brain will assume it is recovering from the stroke.

An alternative to using the false memories to create a cover is to create a lie to tell why their brain is in a jar. It is far more bold and risky and more likely not to work. An example would be to convince the brain that they signed up to have their brain put in a jar. Tell the brain that an unfortunate side affect of the transfer is that it causes memory loss of more recent memories and it is common for those transferred not to remember up to seven days before they got transferred, which is when they consented to under go the procedure. If the brain in the jar gets a chance to talk with other brains in jars, they would corroborate that they too experienced memory loss, but with the excellent help of the doctors they were able to eventually remember it (which this too can be a lie). At this point try and help them reconstruct their last week of memories, and in the process implant a week's worth of false memories that lead them to the decision. The advantage with this is that they are fully open to the fact and you do not have to worry about them finding out.

Disclaimer: I am not a doctor, I only play one on Stack Exchange. As with any drugs please consult with your doctor to make sure Amobarbital is right for you.


A massive, coordinated PR campaign to convince the entire populace that lots of people have already been uploaded into a vat. Have some people claim that everyone is in a vat. Plant lots of people claiming that things about them are wrong. Then have it uncovered that it was just a practical joke taken way too far. ("We didn't know it would permanently change his skin color," says older brother.) Then when people really are put in a vat, they'll think they've just been the victim of one of these pranks. Government disinformation for the win!!!


Partial dreamstate induced by carefully targeted magnetic fields.

In humans whose brain is still insde their skull this is known as transcranial magnetic stimulation, and it can do fun things like induce out-of-body experiences or a sense of presence, or for that matter, decrease the activity levels of the critical parts of the brain (the stuff that allows you to sometimes realize you're dreaming when a particularly egregious break of logic happens in a dream).

When examining REM sleep dreams for memory content, one finds that episodic memories are rare (see Baylor and Cavallero 2001) and typically emerge as disconnected fragments that are often difficult to relate to waking life events (see Schwartz 2003). These fragmented REM dreams often have bizarre content (Stickgold et al. 2001; Hobson 2002). For example, the normal rules of space and time can be ignored or disobeyed, so that in REM dreams it is possible to walk through walls, fly, interact with an entirely unknown person as if she was your mother, or stroll through Paris past the Empire State Building. * http://science.sciencemag.org/content/294/5544/1052.long

Supressing (in part) the critical aspects of consciousness (in a way similar to that which happens naturally in REM sleep described above) will generally prevent the subject from questioning the nature of their reality. In case they become aware, a clinical dose of Flunitrazepam will wipe out the memory of becoming aware of discrepancies, effectively working as a reset button for the previous few hours.


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