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“Seeing is believing”… Well, not according to Virtual reality.

Virtual reality (VR) is a big hit these days. From super cool immersive video games to scientific visualizations and simulations, the application of VR is wide and varied with a long history.  For the uninitiated, Virtual reality is simply simulating bits of reality using high-performance computers and sensory equipment.
 But what can it tell us about how we perceive the world? Just imagine you are in a flight simulator. As the virtual plane, you are flying descends and finally touches down you feel the actual forces as it tips and tilts (thanks to a hydraulically operated mockup of a real cockpit), the landing feels like the real McCoy. After a VR experience, one can't help but wonder how it all feels so real and how the senses can be so easily fooled.  Furthermore, if the senses are so easily fooled, then why trust them? To bring out the thrust of the preceding question, consider this analogy. Suppose a certain Minister of Information tweeted that the government has started paying all undergraduates monthly lunch money of twenty thousand Naira. But we know this minister to be a frequent and very convincing liar. He is also fond of deleting tweets when he sees fit. But sometimes he also tells the truth, but in either case, his demeanor is always the same and appears very sincere. Since this minister is your only source of information, do you have reasonable ground for believing that the government will indeed pay undergrads lunch money? I think not, for your only evidence, the minister's tweet would be exactly the same if the government was going to pay or not. We are in exactly the same situation with our senses. They often tell us things we find out not to be true, take for instance driving down the road on a very hot afternoon. You see what appears to be a pool of water up ahead on the road, but as you approach it disappears. There are a lot of other perceptual “illusions” that show that the senses cannot be trusted all the time.

But if our senses can be fooled some of the time, why can’t they be fooled all of the time? It is a well-known fact that our experiences, whether auditory, visual, tactile, gustatory and olfactory depend on processes within our brains. Let’s say you are looking at a nice red juicy apple. Scientists tell us that the apple you are seeing is a result of light reflected from the apple striking your retinas, which causes signals to be sent, via your optic nerves, to more central processing centers in the brain. This then gives rise to your visual experience of the apple. It is easy to notice that this process can also be replicated artificially. A neurosurgeon could just as well stimulate the parts of the brain associated with producing these experiences, bypassing the process in optic nerves and all others. If this can be done for an instance, who’s to say it can’t be done for an individual’s full stream of conscious life? Just imagine being hooked up to a giant virtual reality supercomputer which stimulates the brain to have the sort of experiences that characterize everyday existence (go back and watch the movie matrix).
What all of this shows us is that there is a gap between how the world appears to us and how it truly is. To bolster this point and make it clearer, take the issue of hallucinations. The hallucination of holding a knife in one’s hand can be as vivid, real and indistinguishable from actually holding a knife. Note that in both experiences there is nothing to tell if one is more trustworthy than the other. Hence we must conclude that what one is directly aware of in one case must be the same sort of thing in the other case, otherwise, there would be some difference in the intrinsic character of the experiences. Since in the case of hallucination, what the person is experiencing is not a physical object, it follows that what is being perceived in a normal case is also not a physical object but a perceptual representation of it in the mind.
The philosopher Howard Robinson has proposed an argument in support of this which can be summarized as follows;

1. By stimulating the brain so as artificially to produce a neural process that is normally associated with a certain normal perceptual experience, it is possible in principle to bring about a hallucination that is subjectively indistinguishable from that experience.

2. But if the immediate causes of normal perceptual experiences and their hallucinatory counterparts are of the same sort, then these effects must be of the same sort as well.

3. In the case of hallucinations, the effect is obviously direct awareness not of any external physical object, but rather of a subjective mental, perceptual representation of an external object.

4. So in the case of normal perceptual experiences too, what one is directly aware of must be a subjective perceptual representation.

To conclude, what VR and other such related experiences tell us about the world is that we do not experience the world and the objects in it directly. The light from the star Alpha Centauri takes over four years to reach us, and light from other celestial objects takes much longer - in many cases, so long that some of the objects we see in the night sky no longer exist! So, again, how could your awareness of these objects fail to be indirect? How could you be directly aware of something that might not even exist?

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