A computer chip has been developed that can imitate brain plasticity, the way in which the brain adapts and responds to new information. “Some scientists can foresee ‘a new kind of evolutionary development that involves somehow meshing bodies and machines. We may now consider the idea of ‘brain chips’ as part of a science fiction movie,” says MIT’s robotics expert, Rodney Brooks. There are other studies to suggest this idea is not just science fiction.
In an article published in the journal Proceedings of the National Academy of Sciences, MIT researchers have come up with a silicone chip that is able to simulate single brain synapse, imitating the chemical, ion-based communication between neurons (brain cells).
Principal research scientist Chi-Sang Poon of the Harvard-MIT Division of Health Sciences and Technology, along with his team, came up with this computer chip in order to help neurologist learn more about how the brain works. It could also be of use in neural prosthetics, such as artificial retinas.
Professor of Neurobiology at the University of California at Los Angeles, Dean Buonomano, says “The new chip represents a ‘significant advance’ in the efforts to incorporate what we know about the biology of neurons and synaptic plasticity onto CMOS chips.” He added, “the level of biological realism is impressive.”
“If you really want to mimic brain function realistically, you have to do more than just spiking. You have to capture the intracellular processes that are ion channel-based,” Poon says. Poon is referring to how, in previous attempts, the circuits they had built used 400 transistors and standard manufacturing techniques to build a chip that allows the current to flow through in a finely tuned analog (not digital, on/off style). With these chips they are able to simulate the firing of an “action potential” (called spiking), but were not able to produce the spiking in all circumstances.
“Now,” says Poon “we can tweak the parameters of the circuit to match specific ion channels. We now have a way to capture each and every ionic process that’s going on in a neuron.” Simulating brain circuits many times faster than high-capacity digital computers can, this analogue chip can move even faster than the brain itself is capable of, reports the MIT researchers.
Although the human brain is extremely complex, it is worth noting that, with over 100 billion neurons, each one can be connected to thousands of other synapses. This chip represents a giant leap forward in the field of computational neuroscience, but it can not take over complete brain functions. That would require a detailed circuit diagram of the brain, its thousands of different strands of synapse and neuroconnectors, and more than processing power and imitation of neural activity.
When you take into consideration that scientists are still trying to trace and simulate the flatworm’s simple 302-neuron brain, you can imagine how far away they are from trying to simulate the human brain. It doesn’t appear it will happen anytime soon.
About the author:
Ron White is a two-time U.S.A. Memory Champion
The Globe and Mail — The torrent of novelty: Are our brains equipped to handle today’s rate of innovation? by Winifred Gallagher: http://www.theglobeandmail.com/life/health/new-health/conditions/brain-health/the-torrent-of-novelty-are-our-brains-equipped-to-handle-todays-rate-of-innovation/article2287499/
Zdnet.com — MIT creates analogue “brain” chip: http://www.zdnet.com/blog/emergingtech/mit-creates-analogue-brain-chip/3009