Similarities and Dissimilarities Between the Brain and a Computer

What are the similarities between the brain and the computer?

1. Both use electrical signals to send messages. The brain uses chemicals to transmit information; the computer uses electricity.
2. Both transmit information. A computer uses switches that are either on or off ("binary"). Neurons in the brain are either on or off by either firing an action potential or not firing an action potential.
3. Both have a memory that can grow. Computer memory grows by adding computer chips. Memories in the brain grow by stronger synaptic connections.
4. Both can adapt and learn. It is much easier and faster for the brain to learn new things. Computer is to be programmed.
5. Both have evolved over time. Computers have evolved much faster than the human brain.
6. Both need energy. The brain needs nutrients like oxygen and sugar for power; the computer needs electricity to keep working.
7. Both can be damaged. It is easier to fix a computer - just get new parts. There are no new or used parts for the brain. Both a computer and a brain can get "sick" - a computer can get a "virus" and there are many diseases that affect the brain. The brain has "built-in back up systems" in some cases. If one pathway in the brain is damaged, there is often another pathway that will take over this function of the damaged pathway.
8. Both can change and be modified. The brain is always changing and being modified. There is no "off" for the brain - even when an animal is sleeping, its brain is still active and working. The computer only changes when new hardware or software is added or something is saved in memory. There IS an "off" for a computer. When the power to a computer is turned off, signals are not transmitted.
9. Both can do math and other logical tasks. The computer is faster at doing logical things and computations. However, the brain is better at interpreting the outside world and coming up with new ideas. The brain is capable of imagination.
10. Both can do multitasking. Number of programs can be run simultaneously. A brain also does some multitasking using the autonomic nervous system. For example, the brain controls breathing, heart rate and blood pressure at the same time it performs a mental task.
11. Both brains and computers are studied by scientists. Scientists understand how computers work. There are thousands of neuroscientists studying the brain. Nevertheless, there is still much more to learn about the brain..

What are the differences between the brain and the computer?

1. Brains are analogue; computers are digital.
2. The brain uses content-addressable memory. In computers, information in memory is accessed by polling its precise memory address. This is known as byte-addressable memory.
3. The brain is a massively parallel machine; computers are modular and serial
4. Processing speed is not fixed in the brain; there is no system clock
5. No hardware/software distinction can be made with respect to the brain or mind
6. Synapses are far more complex than electrical logic gates
7. Unlike computers, processing and memory are performed by the same components in the brain
8. The brain is a self-organizing system
9. The brain is much, much bigger than any [current] computer. Accurate biological models of the brain would have to include some 225,000,000,000,000,000 (225 million billion) interactions between cell types, neurotransmitters, neuromodulators, axonal branches and dendritic spines, and that doesn't include the influences of dendritic geometry, or the approximately 1 trillion glial cells which may or may not be important for neural information processing. Because the brain is nonlinear, and because it is so much larger than all current computers, it seems likely that it functions in a completely different fashion.