A frequently mentioned reason for the likelihood of human-equivalent AI being created within decades rather than longer is the fact that affordable computing power is approaching most estimates of human brain processing power.

100 billion neurons firing at 200 Hz — this is a basic neurological fact. Yes, there are many additional shades of complexity, including dendritic spines, neurotransmitter concentrations, and so on. Still, all of these put together seem to change the estimated computational requirements by no more than 2-3 orders of magnitude.

I can tell that I am speaking with an ideologue when they are unaware of the facts mentioned above, are informed of them, but that information then has no impact whatsoever on their subjective probability estimates of human-equivalent AI being created in the next few decades. Many people seem to act as if computing power has no influence whatsoever.

In contrast, Ray Kurzweil, Hans Moravec, and some other advocates of strong AI have seemingly acted as if computing power is everything — that when we have human-equivalent computing power, we’ll immediately have human-equivalent AI. That is wrong too.

It is easy to take the middle path. Particularly when the notion of human-equivalent computing power being available is combined with neural data from extremely high-resolution brain scans (a brute force argument for the eventual plausibility of human-equivalent AI if there ever was one), critics begin to sound incredulous when they do not revise their probability estimates for AI whatsoever.

One particular confused meme that has been making the rounds for decades is the notion that some fundamental breakthrough in computing would be necessary to implement human-equivalent AI. A digital computer can simulate any possible analog signal, as long as it has the computing power — the inverse is not true. This is proven thousands or millions of times daily as old VHS and other magnetic tapes are converted into the digital medium.

If I had a computer faster than most expert estimates of human brain computing power and an extremely high resolution scan of the human brain, the burden of proof would be on the critics to say why I couldn’t create a human-equivalent AI immediately. The objections here tend to circulate around dualism, mysticism, biology-worship, quantum mumbo-jumbo, etc.

Yet, if we had sufficiently high-resolution scanners, we could just copy the brain’s design without understanding it.

It's a myth. We use 100% of our brain. The idea that we only use 10% of our brains is probably such an enduring myth because it's comforting to think we have spare capacity. The 'unused' 90% could take up the slack after brain injury or offer the possibility for miraculous self-improvement. This flexible factoid has been used not only to sell products to enhance our brain's performance, but also by psychics like Yuri Geller to explain mystical cutlery bending powers.

1.If we only use 10% of our brains then damage to some parts of our brains should have no effect on us. As any neurologist will tell you, this is patently not true.

2.From an evolutionary perspective it is highly unlikely we developed a resource-guzzling organ, of which we only use 10%.

3.Brain imaging such as CAT, PET and fMRI shows that even while asleep there aren't any areas of our brain that completely 'switch off'.

4.Parts of the body that aren't used soon shrivel and die. Same goes for the brain. Any neurons we weren't using would soon shrivel and die.

The structure of the brain and its metabolic processes have also been carefully examined, along with the diseases that afflict it. None of this work has suggested there is a hidden 90% that we're not using. Unfortunately.

Anyone who still maintains we only use 10% of our brains after this fusillade of fact has to come up with a counter-argument for each one of these. Actually, you might argue that imaging technology is rubbish or the neurons are only working at 10% capacity, but refuting all four, taken together? Now that's tricky.

http://en.wikipedia.org/wiki/10%25_of_brain_myth

there is an effort of emulating human brain called The Blue Brain Project which is the first comprehensive attempt to reverse-engineer the mammalian brain, in order to understand brain function and dysfunction through detailed simulations.

http://bluebrain.epfl.ch/