Building an Artificial Brain

Last night I was up, unable to sleep thinking about what would happen if we had the technology to create a computer model of the human brain with every one of the neurons correctly mapped. Would that be enough to create an artificial person and how would you interact with it.

The human brain is the product of billions of years of evolution and is very tightly coupled to the human body. An exact copy of the human brain would probably require a “body” to go with it.

The first question that came to mind is what would be the inputs. Sight and sound are pretty easy to see how that might be able to translate into a virtual neuron interface. Retinal implants provide sight to the blind, and cochlear implants provide hearing by directly stimulating the nervous system connections. Simulating these nervous system connections and connecting them to physical visual and audio inputs would be crucial.

The second question is what outputs would be most feasible? From people with severe spin injury comes the idea of communicating by blinking an eye. We cold tie into the motor control system in the brain and connect it to a virtual muscle to “blink”. What about speech? That seems very nearly impossible. The brain controls speech by the coordination of lots of muscles – diaphragm, vocal chords, tongue, lips, jaw etc. Creating a physical copy of these systems to connect to the nervous system seems infeasible. Similarly a speaker takes as input a wave form, and translating the complex inter-workings of all those muscle signals into sound also seems much too difficult. However it would be an interesting experiment to see if the human brain learn to could control audio from a speaker if it was connected directly to the nervous system.

The next question is about speed. Human brains operate at human speeds, but a simulation may operate much slower or much faster. Imagine talking to someone with an IQ of 40. You’re waiting for them to complete a sentence, annoyed that it’s taking so long to arrive at the obvious point they’re trying to make. We may have a similar interaction with an artificial brain – or it could be the opposite.

Thinking about this further. The nervous system below the neck isn’t required for cognitive ability. Quadriplegics have the same mental capacity as everyone else. So we could probably ignore all the other body parts and sensory inputs.

Even if we did manage to create a digital simulation of the human brain and managed to connect visual and audio inputs and some output communication mechanism I suspect it would probably be take another generation of development before it could actually function as anything other than a vegetable. But still… it would be pretty amazing.