9 Are humans subjected to simulations?

It may seem hard or impossible to decide whether humans live in a simulated world and who would be the operator. Insight on this question, however, may be obtained if one examines some implications of the conjecture.

Simulation hypotheses, which hold that a subject is immersed in a fake reality, have been typically formulated as brain-in-a-vat paradigms, according to which an unspecified operator creates a model of virtual reality and connects it with an otherwise isolated brain. The model, which includes the representation of the physical person and of his brain, is not simply shown as a film to a spectator, but is put in an interactive relation. Not only is the virtual sensory input fed to the envatted brain through appropriate neural afferent stimulation; the neural motor commands are also recorded, and their virtual effects on the model are evaluated, carried out and signaled back.

It has to be preliminary noted that the question should be better formulated as 'Am I subjected to simulation?'. Actually, simulation implies that the other humans in the scene are virtual, being irrelevant if they exist or not in the real world.

However, a main problematic point to be noted is that the hypothesis, if true, would be formulated by the real, envatted brain and referred to the real world, but would be in keeping with the virtual world and its physical laws, as created by the operator. Even the term 'brain' would be used with reference to the image contained in that model. In order for the hypothesis to be valid, therefore, virtual brain and physical laws ought to coincide with those of the real world; otherwise, the conjecture would be senseless. No argument is provided to discuss the operator's choice to maintain in the simulated world the laws and the brain of the real one. But, in spite of the appearances, the coincidence of the two worlds gives the hypothesis a rather conservative character.

This is not the only drawback. Others would come into play if the envatted subject decided to act on his own brain: for instance, he might assume a drug of predictable effects (a memory disruption, a variation in mood, an improvement in thought performance), or modify his brain by surgery.
In these cases, the operator could not limit his action to producing the appropriate modifications in the virtual brain. To make the subject introspectively experience the expected effects, he should also perfuse the drug or carry out the surgery on the real brain.

Thus, the operator would be forced to carry out extremely difficult or maybe impossible physical interventions, while turning, on the other side, into a dutiful actuator of the commands emitted by the otherwise subordinate brain. One may wonder, at least, why an operator endowed with such extraordinary capacities should bother to create a simulated situation so conservative, constrained and demanding.

Other similar cases, quite cumbersome to be actuated, could be envisaged: for instance, if the isolated brain, not knowing to be already envatted, would dispose to undergo an envatting procedure and would predispose in advance the virtual reality to be exposed to.

All this denounces the simulation hypothesis as a convoluted and ill-formulated conjecture.

In spite of this, a type of simulation which strictly corresponds to the definition given above takes place in a particular case, i.e. during dreaming. In a dream, a model of reality is produced, fake sensory input is generated, the effects which the brain commands would yield are actuated upon the model, and the modified situation is fed back to the dreamer. A major difference is that the dream-producing operator, being localized inside the neural stuff of the brain, could in principle be identified and investigated.
Note, incidentally, that this might suggest a procedure much simpler than brain envatting to implement a simulation upon a human being, i.e., by gaining control upon his center for dreaming, and taking advantage of the already built neural machinery - a type of approach that might be named neural hypnosis.