The Speed of Thought

Computers are becoming faster and more powerful all the time and those improvements have been mainly due to better hardware. Future improvements, however, may well rely increasingly on better architecture and software. One reason why this seems likely is that the human brain, with its very different architecture, dramatically out performs computers in performing various tasks (such as perceiving an object in a complex visual scene). If computers are to match the brain's performance, they likely will need to exploit features of the brain's design. In some regards the brain's hardware is far beyond that of a computer. Its "wires," for instance, would go to the moon if stretched out. That's about 10,000 times longer than all the wire in a typical microprocessor chip. Similarly, the brain has about a hundred million million synapses (the connecting junctions between neurons) which is many thousands times more than the  number  of  transistors  in  the  microprocessor.  But  perhaps  even  more  amazing  is   the   brain's architecture and software. For instance, whereas computers are based on the Von Neumann architecture which separates computation and memory, the brain combines these elements in ways not well understood. Also, whereas computer components are highly predictable (deterministic) the brain's synapses are much less predictable (probabilistic). Any given signal may have only a 20% chance of successfully crossing the synapse and this is compensated with substantial redundancy. Aside from tremendous fault tolerance, this allows the brain to rapidly increase signals by modifying the probability of synapse crossing. Such differences provide a profoundly different, and probably more powerful, computing architecture compared to the microprocessor. As one paper explains: Because the brain is not bound by the Von Neumann architecture, exactly what a particular neural circuit computes can be modified on the fly without reference to other circuits (as when we shift our focus of attention from one thing to another) and can also remember things for a lifetime (how to ride a bicycle). Exploiting the brain's architecture, however, will not be easy. For instance, we need to better understand how to use parallel computers: The problem with emulating the brain’s massive parallelism, however, is that we are not even close to being able to use the increased hardware power efficiently; how to program parallel computers is a very active subject now in computer science. But even the parallel programming problem is only the beginning. The far more difficult problem is to divine just what information processing and computations are carried out in the brain's neural circuits: we believe the problem is not computer power and ability to program parallel machines, but rather our nearly total ignorance about what computations are actually carried out by the brain. Our view is that computers will never equal our best abilities until we can understand the brain’s design principles and the mathematical operations employed by neural circuits well enough to build machines that incorporate them. If you find the brain's design astonishing, consider this even more astonishing fact: evolutionists say it all just evolved. The ability of the brain to develop from scratch, and its design and operation, they say, all arose from mutant forms. Amazing.  Source: Darwin's God

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