(Featured image from newscientist.com)
Scientists are increasingly answering the questions normally left to philosophers: How do I know I exist? What is reality made of?
The short answer is, you don’t know you exist. Consider the fact that with every passing moment, we get closer to creating intelligent machines, maybe even ones with a consciousness. If we could create something like this, could someone – or something else – do it too?
If humans were one day able to create simulations populated with conscious beings, it’s also then possible that we too are living inside such a simulation. There have been projects seeking to build entire animal brains from scratch, modelled on existing ones down to details such as the connections between myriads of individual neurons. When very simple versions were given robotic bodies, they behaved like the creatures they were modelled on. It’s only a matter of time before we create virtual beings inside computers.
We will never find out whether or not we are simulations ourselves, but we clearly have a very robust sense that ‘I exist’. Where does this sense come from?
Psychological conditions like Cotard’s syndrome can give us clues – sufferers are convinced they do not exist, with their brains showing important anomalies in regions associated with rational thought and internal awareness. Activity in this region was as low as someone minimally conscious, creating a perception of non-existence. These studies have shown our brains generate the feeling of existence by creating a vivid perception of our bodies and its various states; any malfunctions in these regions cause us to question our existence.
Our brains are being constantly bombarded by countless signals from the body and our external environment and must predict what’s causing them. It does this by creating internal models of the body and the environment, maintaining prior knowledge and testing its own models. In this way, the brain is like a prediction machine that is continuously trying to prove its own existence.