What links these two pictures?
The shortest answer is 100 billion. Our galaxy Milky Way, similar to the one in a photo (galaxy M31), has about 100 billion stars. The brain in the picture on the right has about 100 billion neurons. Thus, the scale of knowledge processing system a brain is which is truly astronomical. Whether the entire functionality of the brain, our consciousness, is simply result of scale (economies of scale)? I do not think so. The posed question is the result of the observed systematic increase of multiprocessor systems and an increase in the speed of information processing as well as an increse of memory capacity. Computer systems are slowly coming to some of the parameters of the brain in memory capacity and speed of processing. If a simple multiplication of CPU and memory required to meet those parameters will allow us to achieve similar functionality as the brain? Intelligence? And especially a consciousness? Of course not. Even if these systems are being built in the assumption as artificial neural networks implemented in hardware. It is a long and winding road to achieve intelligence of human being but I believe it is generally posiible. The most serious question is regarding the consciousness of course because even we aren't able to understand and to define it well.
One of the interesting projects looking for hardware-based artificial intelligence is SpiNNaker, mapping neural networks onto a massively-parallel chip multiprocessor. The leader of the project is Steve Furber professor at the University of Manchester. The goal is
to directly mimic the functionality of the brain. In fact it is neural network implemented in hardware and nicknamed "brain box". The finished Spinnaker will model 1% of the human brain's capability, or around 1 billion neurons. The SpiNNaker project aims amongst other things to investigate:
How can massively parallel computing resources accelerate our understanding of brain function?
How can our growing understanding of brain function point the way to more efficient parallel, fault-tolerant computation?
(the last after Wikipedia). It will be very interesting to observe the results of the researches. But in that context I would like to ask the question: Is the amount going into the quality automatically? Is the amount of neurons crucial to our intelligence, especially consciousness? I think to some degree - yes, but it is not all. Finally, some people have proper amount of neurons and they are seriously mentally ill ! At the same time, are we sure that only neurons and synapses are responsible for our abilities, intelligence not saying about consciousness? And what about glial cells? Their total number is 10 times greater than the number of neurons, it gives 1000 billion of cells! So may be the paradigm based on neuron's role is wrong? If yes, may be it should influence our researches in artificial intelligence, especially in artificial neural networks area? The interesting book on role of glial cell is by Andrew Koob: "The Root of Thought, Unlocking Glia".
Thanks to scientists from neurology, biochemistry, computer science - especially from artificial aintelligence, and others we already know a lot about brain, but still a lot more we do not know.
It is well known Turing test for machine intelligence.
May be signal that we reached the human level of machine intelligence will be situation, if one day,when the computer badly works won't be fixing/repair it computer specialists but computer psychiatrists?