The Singularity is Near: When Humans Transcend Biology

by Ray Kurzweil

There are a number of other key ways in which the brain differs from a conventional computer: • The brains circuits are very slow. Synaptic-reset and neuron-stabilization times (the amount of time required for a neuron and its synapses to reset themselves after the neuron fires) are so slow that there are very few neuron-firing cycles available to make pattern-recognition decisions. Functional magnetic-resonance imaging (fMRI) and magneto-encephalography (MEG) scans show that judgments that do not require resolving ambiguities appear to be made in a single neuron-firing cycle (less than twenty milliseconds), involving essentially no iterative (repeated) processes. Recognition of objects occurs in about 150 milliseconds, so that even if we “think something over,” the number of cycles of operation is measured in hundreds or thousands at most, not billions, as with a typical computer. • But it’s massively parallel. The brain has on the order of one hundred trillion interneuronal connections, each potentially processing information simultaneously. These two factors (slow cycle time and massive parallelism) result in a certain level of computational capacity for the brain, as we discussed earlier. Today our largest supercomputers are approaching this range. The leading supercomputers (including those used by the most popular search engines) measure over 1014 cps, which matches the lower range of the estimates I discussed in chapter 3 for functional simulation. It is not necessa...