Weighing in at about three pounds, the human brain is a marvel of evolutionary engineering. The brain transforms signals from millions of sensors located all over the body into appropriate muscle commands to enact a behavior suitable to the task at hand. This closed-loop, real-time control system remains unsurpassed by any artificially created system despite decades of attempts by computer scientists and engineers.

The brain’s unique information processing capabilities arise from its massively parallel and distributed way of computing. The workhorse of the brain is a type of cell known as a neuron, a complex electrochemical device that receives information from hundreds of other neurons, processes this information, and conveys its output to hundreds of other neurons. Furthermore, the connections between neurons are plastic, allowing the brain’s networks to adapt to new inputs and changing circumstances. This adaptive and distributed mode of computation sets the brain apart from traditional computers, which are based on the von Neumann architecture with a separate central processing unit, memory units, fixed connections between components, and a serial mode of computation.