Essay Questions
2. What the strengths and weaknesses of communication in the central nervous systems compared with the digital computer?
Key Points:
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Some of the issues here overlap to some extent with the response to question (1) above: for example, the brain is more flexible (so it can do things which no computer can do, such as processing ambiguous information efficiently both in the day and at night) but it is slower than the digital computer (which can, for example, ‘crunch numbers’ much faster than people can).
• Some similarities exist in terms of the modular arrangement of the ‘hardware’, speeding up communication and saving space. For example, a similar modular arrangement is used for laying out printed circuit boards, and in connecting different input (e.g. scanner) and output (e.g. printer) components to a desktop computer.
• Discuss how communication in the brain takes place via the action potential, which is the same size whether the depolarizing stimulus is only just strong enough to reach threshold or depolarizes well beyond threshold, and how this relates to the computer.
• Point out that the brain can solve immensely difficult computational problems, such as judging variable distances, identifying objects as being the same even if the images which they cast on the retina may vary, walking through complex environments relying solely on vision to guide us. These abilities are way beyond the capacities of current computers, even though their processing elements operate very much faster than our neurons.
