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nice thoughts. Now, I have no idea what I'm talking about, but i imagine the brain of a red-blind person wouldn't have a fully developed pathway to "see" red. I

• ars 16y ago
  They can't make any sense of the sound. They can mange to hear sound, but not understand language. Those pathways close during childhood and don't open back up. There are no "unused tags" like he imagines. The brain is not pre-programmed. It gets programmed based on how it's used. You give it a sense that is distinct from other senses, and it finds a way to use it. If you don't then that sense simply doesn't exist in that brain - there are no unused spots. If you have ever used a tool, or played a game to the point that when you think "do this" the tool or game just does it, without you consciously thinking of the actions, then you have experienced this. The tool becomes a part of you. The brain simply opens another "channel" for that. Or the sounds a game makes. You don't think "this kind of beep means this", no, you just "know" that the game is doing something based on the sound. The brain is very flexible, and unlike a computer it does not have fixed input/outputs. Another example is someone who wore a belt that always vibrated on the side that pointed north. After a while he had a new sense! He just "knew" where north was. He did not feel "oh a buzz on my front left". No, he just knew north is there. He brain integrated this new sense with the visual sense, and he experienced that a particular street points in a particular direction. Just like you would tag a house with a color "red", he tagged it with a direction. What did this "northiness" look like? I don't know - I guess it looked like north.
  • nooneelse 16y ago
    The extendability of our sensory modes does not disprove that we and other animals come pre-programmed in various ways in both our input and output. I went into a developmental neuro-biology course thinking much as you seem to be, trying to tear all the "it's inborn" B.S. away from the functionally super-flexible neurons. But the experiments and scientific observations just don't support that project in all cases. To name two: brain regions fully formed for spatial management/processing of visual signals in the absence of any signals from an eye being allowed to ever reach them, transplanting the song/chirp patterns from one species of bird to another by splicing neurons from a developing embryo of the first to the developing embryo of the second. How are these to be explained if not by something that clearly qualifies as some form of "pre-programming" of the neural substrate for sensation and behavior? Extendability and plasticity are not necessarily defeaters to innateness. They can coexist.
    • joeyo 16y ago
      What you say is true, but it's worth noting that, as a rule, phylogenetically "higher" organisms do tend to have more plasticity and (perhaps as a consequence) less ability to regenerate neurons). Your songbird example is a good one. There are many species of birds that develop near normal song repertoires in the absence of con-specifics (or even, in some cases, hearing!) but trying to extrapolate that to human speech processing, or even mammalian auditory processing, is fraught with problems.
• russell 16y ago
  My niece had an inherited congenital defect where one eye was weaker than the other, which if untreated, she would have eventually gone blind in the weaker eye. Fortunately it was discovered in time. For quite some time she wore a patch over her good eye, until the bad eye strengthened itself to carry its share of the load. I dont know if the defect was in the eye itself or in the neural pathways, but I suspect it was the eye itself and the strengthening was in the neural pathways.