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Brain consciousness

  1. Mar 20, 2004 #1
    What gives rise to what we call consiousness? As I can't think of a better definition of consciousness than subjective experience (emotion, feeling), we can use that unless someone comes up with something better.

    What functions and structures of brains yield or are associated with consciousness? Is there anywhere in the animal kingdom where we can make distinctions between consciousness, unconscious, and perhaps semi-conscious (if that makes any sense)?

    I am interested in a scientific discussion of neurology.
     
  2. jcsd
  3. Mar 20, 2004 #2
    I am also interested in the evolutionary aspects of this.
     
  4. Mar 22, 2004 #3

    loseyourname

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    Looks like no one else is. Seriously, though, I can post a couple of things, but not much research has been done on this. I suggest you go to Science and Consciousness Review, where they the small amount of information that is available on this topic.

    I agree with you that it is a very important topic. It is unfortunate that science has all but ignored it for so long.
     
  5. Mar 22, 2004 #4


    And what is the root of emotion/feeling? thought. I believe that is an improved definition of consciousness.
     
  6. Mar 23, 2004 #5

    Moonbear

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    I wasted over an hour of my life today listening to a philosopher talk on this very topic. At least the resultant discussion among the scientists present made it worthwhile.

    Science hasn't ignored the question. In fact, it's pretty much a given among neuroscientists that consciousness has a neural basis. It seems it's the philosophers who are still stuck in a rut trying to distinguish some sort of mind/brain dualism, or the theists who think the soul is separate from the body.

    The real problem is the lack of a clear definition of consciousness and our limitations in how we can measure it...we have to rely on an output of that consciousness...an action, a spoken accounting of the memory of something, a numerical ranking of a sensory experience...none of these are ideal. To me, consciousness is a collection of sensory experiences and the response to those experiences that occurs in the cortex of the brain. The cortical response distinguishes consciousness from other responses such as reflexes or autonomic functioning of our body, of which we are unaware. Awareness of something requires involvement of the cortex.

    In terms of identifying scientific literature on the neural basis of consciousness, you're not going to find it by looking up the term "consciousness". That, much like trying to define "spam" or "pornography", is something that has too much of the "I know it when I see it, but don't know how to define it precisely" stigma attached to it. Instead, you will find much about specific aspects of consciousness...sensory perception, speech and language development, learning and memory, motivation and reward, etc.
     
  7. Mar 24, 2004 #6

    loseyourname

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    The best studies you might find are analyses of brain wave patterns during sleep and during waking states. These can at least point to the portions of the brain that are responsible for our self-awareness. I hate to do this again, but I'll post what I can find later. I'm on my way out to eat right now.
     
  8. Mar 25, 2004 #7

    Moonbear

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    Actually, I don't think sleep/wake studies are going to give you any answers on consciousness. Afterall, you're not "unconscious" when asleep. It's possible we are more aware of our environment than we remember when we're asleep. If we weren't aware of our environment while sleeping, then thunderstorms wouldn't wake us, neither would alarm clocks for that matter. Ever fall asleep with the TV on only to incorporate what's on the TV into your dreams? So, even though we might not remember what happened while we were asleep, it doesn't rule out consciousness.
     
  9. Mar 25, 2004 #8
    No one knows how, but the where of consciousness is known, and that is in the Thalamo-cortical circuit of the brain.

    The thalamus is an extremely important part of the brain, kind of a grand sentral station through which almost all sensory imput is routed when it comes into the brain via the nerves of the senses.

    During a specific kind of seizure, the absense seizure, the only part of the brain affected by the seizure activity is the thalamo-cortical complex, and when this happens the person's consciousness just completely shuts off, without any other brain functions being affected. Absence seizures usually only last a few seconds. The person's consciousness shuts off, they stop everything, staring blankly, then their consciousness comes back on. They are aware there has been a leap forward in time as if as few seconds of a movie have been cut out.

    NOVA Online | Secrets of the Mind | The Electric Brain
    Address:http://www.pbs.org/wgbh/nova/mind/electric2.html
     
  10. Apr 1, 2004 #9

    loseyourname

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    It's hard to pin down certain actions that are conscious and others than are unconscious, given that there are many acts that are normally unconscious that we can become conscious of. The same thing with memory. I think we have a pretty good idea of what memory is and where it is located, but why is it that we are conscious of any given memory at any given time and not another? Does anyone here know?

    Reflexive responses can also be brought under conscious control, or many of them can be. From what I've read in intro texts, the prevailing idea seems to be that consciousness is a scanning mechanism of some sort that can focus in on any given part of the brain at any given time. How is this controlled?

    Also, with the sleep/wake studies, what I meant is that in sleep we become unaware of sensory input, whereas when awake, we are aware of these. This can help with determining what causes the awareness.
     
  11. Apr 2, 2004 #10
    Maybe consciousness arose in conjunction with increased communication. How can you be aware of yourself if you have nothing to compare yourself too? Communication with others would be needed to analyze what kind of place you take in in this universe.
     
  12. Apr 2, 2004 #11
    There is a neurologist at the University Of California, San Diego named V.I. Ramachandran, who occasionally appears on educational channels here talking about various aspects of neurology. In one lecture he strongly made the point that consciousness is dependent on differences. He pointed out that perception of the difference between one phenomenon and another, be it light and dark, silence and sound, green and red, soft and hard, etc. is at the heart of all awareness. He would agree that being aware of yourself is essentially dependent on percieving a difference between yourself and something else. His broader message is that awareness of anything depends on percieving a difference between it and something else.

    His conjecture was that, in evolutionary terms, individuals born with finer abilities to distinguish between more subtle differences were better able to hunt and gather food, and stay away from danger. Being healthier and longer lived they procreated more.
     
  13. Apr 4, 2004 #12

    loseyourname

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    Some of you, if you haven't already, should check out the consciousness discussions they have in the philosophy forums. The contrast is amazing.
     
  14. Apr 5, 2004 #13

    selfAdjoint

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    Yeah, well this is a biology forum, and this kind of discussion is appropriate here. If you post this kind of material on the philosophy boards someone will come along and say "But how do we know anything exists?' or "Science says consciousness is unphysical." And the thread will go away with everyone's pet fantasy.
     
  15. Apr 5, 2004 #14
    LOL
    As someone who spends a bit of time in PhilosophyForums.com, yeah, I know what you mean.
     
  16. Apr 6, 2004 #15
    Does anyone have any good links to good studies on consciousness?

    I would appreciate links to information that isnt' written with the assumption that consciousness is solely human or even solely mammalian.
     
  17. Apr 6, 2004 #16
    Then you would expect that our senses would also have evolved to a different level. We do have not very good smell, eyesight, or taste etc. An increase in the capacity of you senses would make more evolutionary sense if this concept is true than developing consciousness and a big brain. Big brains are expensive to operate. They cost a lot of energy. A better nose doesn't cost so much.

    Also the in general intelligence is found in intricate and complex social communities in the animal kingdom. There is certainly a connection between social structure and intelligence. A single step further from intelligence could be consciousness.

    I think the concept is touched upon in Daniel C Dennets book, 'freedom evolves'.
     
  18. Apr 6, 2004 #17

    selfAdjoint

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    We have excellent eyesight in comparison with other animals. It's not just far sight, where the eagle beats us, but generalized sight that enables us to spot subtle clues in a prairie environment. We're good at what our ancestors found it necessary to be good at, and not good at things like smell, that didn't loom large in their needs inventory.
     
  19. Apr 6, 2004 #18

    loseyourname

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    We're also good at creating machines that can sense things an eagle could never even dream of.
     
  20. Apr 6, 2004 #19

    loseyourname

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    I don't think any serious biologist believes that consciousness is confined to humans. In fact, most of the studies I've heard of have been conducted on non-human primates.

    Have you checked the Science and Consciousness Review? I posted a link earlier in the thread. There are a lot of links to studies that have been conducted, although they're in online journals, so you have to pay to read most of them. If you are serious about learning more on this topic, though, it's worth it to purchase a subscription to journals that deal with the topic. You should have at least some working background knowledge of neuroscience as well.

    You might want to check out these as well:

    Journal of Cognitive Neuroscience

    Tucson Consciousness Conferences

    Hypnagogue is going to the conference this year. If you have any questions about it, he's posted a thread in one of the philosophy forums (I don't remember which one) where you can ask him questions.
     
  21. Apr 11, 2004 #20
    Thanks, loseyourname.
     
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