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Brain Usage

  1. Mar 20, 2003 #1
    My Biology teacher had recently said that we actually use only like 4-5% of our brain capacity. Is she correct?[?]

    I think that we are using close to or 100% of our brain capacity. Because the brain uses the highest amount of energy in our body, so i doubt that evolution of such a big brain happened for millions of years, just so that it can guzzle so much energy and provide only a 4-5% output. Highly illogical of a natural selection which will ruthlessly expel such an opposition of efficiency.

    *please correct my bio wherever applicable.
  2. jcsd
  3. Mar 20, 2003 #2


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    Your biology teacher might just be speaking for herself. Most people use much more than that.

    I believe PET scans show that significant brain activity only occurs in a small part of the brain at any one time, but that does not mean that the rest of the brain is not used. There are passive uses that don't show up on PET scans.

    A lot of the brain is made up of fat, not neurons. While you could call this "brain", I don't think you could call it "brain capacity".

  4. Mar 20, 2003 #3


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    You could google - myth brain % - to get some web pages to dispel this myth.

  5. Mar 20, 2003 #4
    maybe 4-5 % for "voluntary" tasks...not reflex...
  6. Mar 20, 2003 #5
    Well, much of reflex originates in the spinal cord (instead of the brain). However, I'm sure that subconscious processes (such as instinct) could use up a good portion of "brain power".
  7. Mar 20, 2003 #6
    not really reflex...not conscious...like smelling,tasting,hearing,the sense of touch...
  8. Mar 20, 2003 #7
    Subconscious bodily processes, right? Well, I don't think they take up that much of the "brain power" (of course, I'm not sure about this, this is just my opinion), and I also disagree with the idea that our conscious mind only takes up 4% of our "brain power".

    I had a thread about this (in the former PFs - entitled "1%of1%, Fur instead of hair, Human Uniqueness?), and this question remained unanswered: why do people say that we use so little of our brain, if it's not true?
  9. Mar 20, 2003 #8


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    This myth is based on an old study on mapping the brain. At the time they could only map 20% of the brain to observable functions (muscle control, sense perception etc.). Some reporter picked this up and wrote How "Scientists discover that we only used 20% of our Brains", Whiich is not what the study concluded.

    Ever since then, the claim keeps being repeated with the percentage going down over time.
  10. Mar 20, 2003 #9
    I remember the thread Mentat, and i remember that lot of people gave good answers.
    Here is mine:
    Remember that you use only the shell of your brain to do intelligent processes (thinking, language proccesses .... etc).
    Since the volume of the shell of the brain is really small somparing to the volume of the brain, people tend to think that we only use x% of our brain to think.
    But you have to remember that you are not able to use any other part than the brain's shell to think, so you should calculate your brain usage comparing to the brain shell, not the whole brain.

    (Note: Other parts of the brain are used for things that are not considered as intelligence, things that all advanced animals share).
  11. Mar 20, 2003 #10
    Thanks, Janus. That makes sense.
  12. Mar 20, 2003 #11
    You're right, there were some good answers there, I guess I just forgot what they were.

    However, I disagree with saying that we only use the "shell" of our brain in intelligent behavior. Is there perhaps a link/book/other reference, that you can direct me to, so that I can better understand your side?
  13. Mar 20, 2003 #12
    You may like this or you may hate this or at least you'll think its a cool idea.what if memory and other functions of the brain work differently than you ever thought it did.what if the brains ability to create consciousness by the physical properties and electrical,causes in the synaptic pathways only create awareness.what if the rest of the brain works off of you commands and telepathically sends messages to the areas of the brain to order functions to happen.like you ask your self the remember something.the information encoded on the cells of the brain are access by the brain previously putting it where it wanted it to then stored the information of where it is near consciousness,like hard drives,when the informations put somewhere its tagged and remembers so it knows where to look for it.
    so all proccesses of consciousness are your abbility to create the proper way of seeing things or instructions that make sense to you to make yourself do somethign are your to create,so when you do your mind follows them as you perform them by visualizing.so all functions you do are the telepathic communications between consciousness and the rest of the brain
  14. Mar 20, 2003 #13
    Does the brain have any vestigial regions, or has the function of various brain parts evolved radically away from their original purpose?
  15. Mar 20, 2003 #14
    Well like we understand,sub conscious is always doing things while we just think.so we have two consciousness thinking at the same time.sub conscious makes these decision for us.it puts memorys where it wants brings ideas to mind reminds us of where we have to be today,because we tell our selfs to and it happens for us,because sub conscious heared what you ask,and did it for you when to time came.we communicate all the time with our inself.we give ourselfs instuction,and our mind carries it outfor us either on purposebecause we did,or when where not paying attention.so conscious commands sub consiousness and sub consciousness carries out the instructions as it makes us think at the same time.so when you ask for a memory the sub consciousness already knows where it put it and retreives it for us,so fast we didnt notice any time delay.so sub conscious encodes the information on the cells atoms just like dna stores our blue prints.the information on the atoms is encoded telepathically by sub consciousness for us.so try making up different types of commands to see what you mind will give you as a response.i do it all the time its hard to explain the thing i do but thats another post
  16. Mar 20, 2003 #15
    Well, i heard it once from a neurologist, but since you are asking for a book, i just found one.
    I have in front of me a book called "The Brain, An Introduction To The Psychology Of The Human Brain And Behaviour, By Christine Temple", unfortunately the book i have is translated to arabic.
    I (after re-translating it into english) quote this part.

    ... and we know that the volume of the whole brain is not the factor that determines the thinking capabilities. For example, the volume of the brain of an elephant is much bigger than the volume of the brain of the human, although the human is much smarter. It seems that the factor that determines intelligence is the ratio between of the brain's shell volume to the brain volume itself. We actually can see that this thin layer (the brain shell) is so large in the human brain that it had to go in and out on the surface of the brain ...

    What do u think now ? :wink:
  17. Mar 20, 2003 #16


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    In the old thread, I visited some of the sites such as "Urban Legend" which tried to dispel this "myth". However, they all ended up confirming it. If the articles found at any of the sites are read carefully enough, it can be seen that they verify the figure between five and 20 percent (depending on the site).
  18. Mar 20, 2003 #17


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  19. Mar 20, 2003 #18


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    That link is to one of the pages I mentioned above, and is typical of the arguments presented in all the sites I have visited. The basic argument against the "myth" that we only use (insert appropriately small number here)% of our potential brainpower can be stated as follows:

    "That is not true because anyone who believes that it is true is trying to prove psychic or telekinetic phenomena!" This is the classic example of what philosophers call the "straw man" fallacy.
  20. Mar 20, 2003 #19


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    The reference to psychic phenomena is not mentioned as a reason against the claim, but as an explanation for why it is so widespread.

    The site Phobos provided mentions some evidence against the claim from PET scans.
  21. Mar 20, 2003 #20
    I've mentioned before that it's quite predominent in the non-tertiary teaching profession. I guess this is another example of it.

    I wish I have been equipped with a good command of evolutionary biology when I first encountered this rubbish at the age of 10.
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