This was the original question.Guybrush Threepwood wrote: Is it possible for us to make a functional model of the human brain?
So, a few WAGs:
1) in terms of hardware, the human brain has ~100 billion neurons, and ~150 trillion synapses. At an OOM level - maybe 2 or 3 OOMs - this corresponds to ~100G of RAM, and ~150T of ROM ('hard drive') in a computer.
Well, I reckon we could easily construct a computer with that much hardware today.
2) for cycle time (or clock speed), the comparison isn't exact, but if the brain were a synchronous machine (it isn't), its clock would run at ~10Hz, which is ~9 orders of magnitude *slower* than today's computers. Of course, a more realistic comparison, involving relevant comparable domains for example, would reduce the gap, but not make it go away.
Again, human brains can be matched or bettered in this respect.
3) turning to resilience and robustness. This is certainly an area where the brain's capabilities are poorly understood. At a very high level ... brains suffer gradual decline in functional capability and performance, and can easily work continuously for 100 years. A significant percentage (1-5%?) do suffer systematic failures which can be compensated for to some extent. In contrast, today's computers are ~1 to 3 orders of magnitude less resilient. Methods and approaches to improve this are known (e.g. how the key Shuttle computers are designed).
However, it's likely to be a decade or two before we come close to matching the human brain's capability here.
4) architecture. At one level we know how the brain is wired; that's where the name 'neural network' came from. In other respects - as zoobyshoe pointed out - we are still likely very ignorant of all that the brain does, let alone how it's wired to enable and perform these activities. We can already build neural networks in silicon, or similate them with code; we can also handle the inherent parallelism, at least in principle.
For what we know today, an artificial brain could be built today, architectually. Say two decades before we discover ~80% of all the key brain architectures, and another decade to emulate these.
5) apps. Some of the brain's apps we know reasonably well (e.g. vision), some we're still likely decades away from even outlining (e.g. personality, social interactions), and some are in-between (e.g. language).
WAG: we might get to an '80%' brain in a couple of decades; this is perhaps similar to zooby's 'very damaged human brain'.
6) integration. IMHO, this is the area we know least about, and don't even know how important it is, in terms of the objective as Guybrush set.
Since we don't know what we don't know, this could take a mere five years to clarify, or over 100.
My conclusion: "Is it possible for us to make a functional model of the human brain?" Not today, but maybe in a limited sense by 2020-2030.