Theoretically the brain is a machine. It has a computer (processor) with neural connections, programmed responses, and a data bank. It has sensors in the body that input information into the computer. It has an output to devices that perform actions, and the brain communicates with these devices through electrical and chemical channels. The comparison of the brain and the computer is a metaphor. When it comes to the brain, we often see the computer as a someday substitute. How is the brain different from a computer? The brain uses chemicals to transmit information, the computer uses electricity. Even though electrical signals travel at high speeds in the nervous system, they travel even faster through the wires in a computer. A computer uses switches that are either on or off. In a way, neurons in the brain are either on or off by either firing an action command or not firing an action command.
However, neurons are more than just on or off because a neuron is constantly getting information from other cells through synaptic contacts. Information traveling across a synapse does not always result in a action potential. Rather, this information alters the chance that an action potential will be produced by raising or lowering the threshold of the neuron. Computer memory grows by adding computer chips. Memories in the brain grow by stronger synaptic connections. It is much easier and faster for the brain to learn new things. Yet, the computer can do many complex tasks at the same time that are difficult for the brain however 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. The human brain has weighed in at about 3 pounds for about the last 100,000 years. Computers have evolved much faster than the human brain. Computers have been around for only a few decades, yet rapid technological advancements have made computers faster, smaller and more powerful. The brain needs nutrients like oxygen and sugar for power; the computer needs electricity to keep working. It is easier to fix a computer – just get new parts. There are no new or used parts for the brain. However, some work is being done with transplantation of nerve cells for certain neurological disorders such as Parkinson’s disease. 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. 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. 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. Scientists understand how computers work. There are thousands of neuroscientists studying the brain. Nevertheless, there is still much more to learn about the brain. “There is more we do NOT know about the brain, than what we do know about the brain”