March 28, 2007

10 Important Differences Between Brains and Computers Difference # 2: The brain uses content-addressable memory -thinking of the word "fox" may trigger thoughts of fox hunting, horseback riding, a sexy woman Difference # 3: The brain is a massively parallel machine; computers are modular and serial -areas of the brain marked as memory centers are also important for imagination Interesting stuff via linkfi
  • Braaaains! Indeed, an interesting read.
  • 11. You can keep a computer on the kitchen table for months.
  • I had a CS instructor who would claim that the brain had the processor power of a Pentium I. I tried many different ways of explaining to him that it didn't make sense to try and make that comparison. Like, if I toss you a set of keys, your brain calculates the entire trajectory near instantaneously so that you can catch it, and simultaneously sends complex signals to your body telling it exactly how much power to use to flex specific individual muscles so that your hand intercepts the keys and you catch them. This also involves mapping the trajectory over a map of the different ranges your multi-hinged arm can travel. The mathematics required to accomplish all this takes a long time to compute. And the brain does this while missing vital pieces of information, like the weight of the keys and the energy expended to send them traveling. The brain requires way more computational power than a computer just to perform commonplace functions. Yet it also underperforms computers in other computational exercises. You can't make general comparisons between the brain and a computer. You can only compare them in specific scenarios, where one usually dominates the other.
  • Unfortunately, this appealing hardware/software distinction obscures an important fact: the mind emerges directly from the brain, and changes in the mind are always accompanied by changes in the brain. Maybe it's because I'm not sure what the article writer means by "changes", "changes in the mind", or "changes in the brain", but I can't parse this statement in a way that contains any information. And if by "the mind emerges directly from the brain" the article writer is trying to say that you can't have a mind without a brain, this "fact" is no different than saying "you can't run software without hardware." I cannot see the distinction that the article writer is trying to make.
  • You know who had a brain, but not a computer? Hitler.
  • I hear if you think too hard about your own brain it might catch on fire.
  • Although this chap is pointing out that the brain is not a computer, his thinking is clearly still shaped and limited by that analogy, and by oppositions drawn from it. If the brain isn't serial, then by golly it must be parallel; if it's not digital, it must be analogue. These may not be helpful ways of thinking about it at all. Probably the most fundamental difference if you ask me is that the brain is not a discrete state machine (actually, real computers aren't either, but they pretend to be), which makes it radically different right from the start. Falling immediately into the trap I have just warned against, I suppose that does suggest broadly a more analoguey than digitaly mode of operation.
  • "Similarly, there does not appear to be any central clock in the brain..." Um... what? That's a rather loaded statement for a circadian biologist... the linked evidence doesn't support the statement, either. The argument that brain cells do not have a mechanism that works like the second hand on a watch does not mean that the brain has no central clock - especially when all evidence I've ever seen shows that the brain has a central clock that keeps track of daily rhythms, and additionally is responsible for setting the time in multiple slave oscillators in other cells and tissues. The "it isn't a digital timer based on repetitive oscillations" line doesn't set well with me. There is quite definitely a set cycle of clock protein production and degradation. This doesn't control ultradian rhythms - rhythms that occur on the order of seconds, etc. - but there is still a centralized clock. These guys need to be careful with their statements.
  • As best as I could tell the clock analogy was based on the "fixed" qualifier.
  • You silly people and your metaphors!!
  • I love these "brain versus computer" arguments. They say more about the human brain's ability to seek patterns (and engage in lengthy, bizarre arguments) than anything else. I have tried - and failed - to derail these arguments in real life by pointing out that the discussion is absurd because a brain IS NOT a computer, and vice versa. True though it may be, pointing out that "You may as well argue about whether apples are better than cats" just doesn't work.
  • Apples.
  • Brains? Yeah, like those don’t map curtain turtles. I could pink a vowel with my brain, but a computer dances on spanish. Pfft. Brains. I don’t knead ‘em. Computers, I mean.