"Frog" brain... or "any" brain...
If it would be able to catch a fly for its dinner, Dr. Modha would be most likely earning himself a Nobel prize.
Unfortunately, Dr. Modha is known for sensationalistic announcements (several years ago it was a "cat" brain, which sadly did not do much either) and little real material.
Putting bunch of simplified models of neurons together is nothing new. It has been done dozens of times before:
- In 2008, Edelman and Izhikevich made a large-scale model of human brain with 100 billion (yes, billion) of simulated neurons (http://www.pnas.org/content/105/9/3593.full)
- Since then, there have been numerous implementations of large-scale models, ranging from million to hundreds of millions of artificial neurons
- Computational neuroscience is my hobby, and I managed to put together a simulation with 16.7 million artificial neurons and ~4 billion synapses on a beefed-up home PC (http://www.digicortex.net/). OK, it was not really a home PC, but it will be in few years
- And, of course, there is a Blue Brain Project, which evolved into Human Brain Project. Blue Brain Project had a model of a single rat cortical column, with ~50000 neurons, but modelled to a much higher degree of accuracy (each neuron was modelled as a complex structure with few thousands of independent compartments with hundreds of ion-channels in each compartment).
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All of these simulations have one thing in common: while they do model biological neurons with a varying degrees of complexity (from simple "point" process to complex geometries with thousands of branches), they all show "some" degree of network behavior similar to living brains, from simple "brain rhythms" which emerge and are anti-correlated when measured in different brain regions, to some more complex phenomena such as acquiring of receptive fields (so e.g. neurons fed with visual signal become progressively "tuned" to respond to e.g. oriented lines etc.) - NONE OF THEM is yet able to model large-scale intelligent behavior.
To put it bluntly, Modha's "cat" or "frog" are just a lumps of sets of differential equations. These lumps are capable of producing interesting emergent behavior, such as synchronization, large-scale rhythms and some learning through neural plasticity which result in simple neuro-plastic phenomena.
But they are NOWHERE near anything resembling "intelligence" - not even of a flea. Not even of a flatworm.
I do sincerely hope we will learn how to make intelligent machines. But we have much more to learn. At the moment, we simply do not know what level of modelling detail is needed to replicate intelligent behavior of a simple organism. We simply do not know yet.
I do applaud Modha's work, as well as work of every computational neuroscientist, AI computer scientist, AI software engineer and also all developers playing with AI as their hobby. We need all of them, to advance our knowledge of intelligent life.
But, for some reason, I do not think PR like this is very helpful. AI, as a field, has suffered several setbacks in the history thanks to too much hype. There is even a term, "AI winter" which came to be precisely as a result of one of those hype cycles, very early in the history of AI.
I am also afraid that Human Brain Project, for all it is worth, might lead us to the same (temporary) dead end. I do hope HBP will achieve its goals, but announcements that Dr. Markram made in the last years, especially (I paraphrase) "We can create human brain in 10 years" will come back to haunt us in 10 years if HBP did not reach its goals. EU agreed to invest one billion euros in this - I hope we picked the right time, but I am slightly pessimistic. Otherwise we will be up for another AI winter :(
Biting the hand that feeds IT
