Is our perception of time real?

Brain: our inner universes

Obviously, people can be made to experience an unreal environment as if it were completely real. This realization alone opens up new territory for VR research: We can try out the limits of what people experience as real and what they consider to be real. We can also explore how the experience of believing things to be real affects other aspects of perception.

The idea that the world we experience is not real appears again and again in philosophy and science fiction, but also in some late-night regulars. In the movie »Matrix« the hero Neo swallows a red pill and realizes that everything he thought was real is a sophisticated simulation, while in reality he lies in a kind of incubator and serves as an energy source for intelligent machines. The Swedish philosopher Nick Bostrom of the University of Oxford concluded from statistical calculations that we could live in a computer simulation that dates back to a post-human age. I do not agree with his argumentation, as it assumes that consciousness can be simulated - which in my opinion cannot be assumed with certainty - but the idea is already thought-provoking.

Mind games like these may be appealing, but they don't get us much further. Let us limit ourselves to the realization: Our perceptual world consists of controlled hallucinations with which the brain makes assumptions about the ultimately unfathomable causes of the sensory signals. And most of us experience such controlled hallucinations as real - but not always. Some people with dissociative disorders perceive their perceived world or even their own self as unreal. Delusions induced by psychedelic substances combine a sense of unreality with vivid perception; the same applies to so-called lucid dreams. Synesthetes combine their sensual experiences; When looking at black writing on a white sheet of paper, for example, some people recognize colors that they perceive as not real. Even in normal perception, for example, after looking directly into a lamp, we see the unreal-appearing afterimage on the retina. So there are numerous cases in which we cannot believe our eyes.

"We behave more appropriately when we see a coffee cup, an approaching bus or our partner, if we experience them as real"

For me, that means that we shouldn't take the perceived reality for granted. It is only one aspect with which our brain makes its Bayesian conjectures about the causes of sensory impressions. But why is it all? Perhaps the answer is: A plausible assumption about the world that comes as close as possible to reality makes more sense for our existence than one that does not. We behave more appropriately when we see a coffee cup, an approaching bus or our partner, if we experience them as real.

An abundance of different realities

There is also a downside to this. It can be seen in the optical illusion with the dress: If we experience things as real, it is difficult for us to assess whether our perceived world deviates from the worlds of others. Such differences may initially be small; however, they can get stuck and strengthen if we absorb more and more different information that best fits our individual worldviews in order to update our models with the help of such one-sided data. We all know this process from the filter bubbles on social media and the newspapers we read. I believe that the same principles apply on a deeper level below our socio-political beliefs as well, right down to our perceived reality. They probably even apply to our self-perception - to the feeling of being me - because the I-experience itself is also a perception.

This gives the constructive, creative mechanisms of perception an unexpected social relevance. If we can better assess the abundance of realities experienced, which are distributed among the billions of brains on our planet, we may find a basis on which a common understanding and a better future can be built - whether between opponents of the civil war, between supporters of different political ones Parties or between two people who live together and have to wash dishes.