Monday, November 09, 2009

Brain Research and Visual Learning

I had the opportunity to hear Wes Fryer keynote today at the 1-1 Laptop Conference in Chicago. He used a stat that I have heard before and have debated a little.

The idea is:

"What we see travels to the brain 60X faster than what we hear"

We discussed it afterward because I have recently looked at that information for another presentation that I was working on. I think it should actually be:

"At any one time 60X more information can travel to the brain from the eyes than from the ears"

Did some research tonight to confirm my off the head numbers today and here is what I found...

Optical nerve fibers = 1,200,000
Several spots on the web - here it is from Wikipedia: http://en.wikipedia.org/wiki/Optical_nerve

Auditory nerve fibers - 20,000 - 30,000 depending on the source
wikipedia has it at 30K

At 20K you get the 60X number

1,200,000/20,000 = 60

That would just impact the amount of information that could be carried at any one time. It is all electrical impulses traveling somewhere between 66-96% of the speed of light (not sure of the speed through the human nerve - but those are the figures for electricity depending on the substance it is moving through). Since neither the eye or the ear are much further from each other, I am not sure it matters.

From: http://www.committedsardine.com/handouts/presentations/UDK.pdf by Ian Jukes, Ted McCain, and Lee Crockett

"30% or the nerve cells in the brain are dedicated to sight, while only 8% are for touch and a mere 3% for hearing"

I conclude the rest must be for touch/smell. So 73% of the sensory neurons we can reach during instruction are dedicated to sight.

There are some numbers out there that seem to imply the greater effectiveness of sight as a sensory source. Any brain researchers out there that want to weigh in on this one?

- Or -

Does anyone else have anything else out there to help confirm/deny this information and the actual true meaning of it all?

12 comments:

  1. I'm at wow, I thought visuals were critical, but is there more data. I need to process this more. Thanks for the post

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  2. Henry,
    I think most learners are very visual, but don't forget that having the nerve fibers does not necessarily mean the processing is better.

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  4. I think one of the advantages of much visual info (as opposed to spoken info) is that you can go back & review/rescan it if it's on a screen or on a page. Much spoken info if missed cannot be reviewed/reheard (unless recorded or repeated), and this may account for the chain of information breaking down more easily.

    Also, fwiw, I've heard audiologist and Central Auditory Procesing Disorder Jeanane Ferre say that the Neurological continuum of processing for auditory input is more complex than it is for other sensory processing.

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  5. Are there any studies that might compare the difficulties of students who are visually impaired with students with a hearing impairment? Which sense is more difficult for a learner to overcome if they have something impaired?

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  7. Interesting thought. I am inclined to think that number of neurons do not correlate to increased learning. I think the connections made in the brain would tend to be more applicable in education.

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  8. oops! That was supposed to be "Central Auditory Processing Specialist Jeanane Ferre".

    So, as I should have made clearer in the original post, I think part of the issue is also the complexity of the of processing, not just the # of neurons required. More complex (in terms of # of steps needed to process data) would seem to mean more places to break down (at least that's what Ferre's research shows, as I understand it).

    Also, it stands to reason that animals with more sophisticated eyesight in relation to hearing (such as humans) would process info more effectively visually than aurally. I would guess that the reverse is true in animals with superior hearing relative to eyesight (say, elephants), but I'll have to do actual research to find out if this hunch is correct.

    Fascinating topic!

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  9. I agree that speed is definitely not the issue. Nerve fibers deliver information to the brain at the same speed.

    However, it also doesn't matter how many fibers there are. The information matters and how the brain processes it matters.

    A gross analogy might be that you could have 2 books, one with 60x as many pages as the other. That alone does not prove that one conveys more information than the other.

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  10. Well, I'm no brain scientist, but I believe that counting up nerve fibers tells you exactly nothing. Even if it were roughly correlated with the speed of information getting from A to B, it tells us nothing about LEARNING which involves all the things that happen next: encoding, storage, and all that jazz.

    It reminds me of an eerily empty freeway I traveled on in China. Six lanes across and we were just about the only ones on it. If road capacity was all there was to consider, then you'd imagine we were on the way to Manhattan. But the road means nothing. They built it ahead of demand.

    As someone who speaks to large rooms of educators myself, I've learned to stop using whizzy statistics like this to wow the crowds. It just make us all stupider.

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  11. Although neuroscience is quite complex, learning still requires the element of meaning-making, I think. No doubt, a great deal of information can travel to the brain through visual media. Well-constructed visual media often conveys messages in ways that text and speech cannot. However, I don't think any of us suffer from not getting enough information fast enough. If anything, we get too much too quickly without sufficient time to process it, apply it, evaluate it, create something that demonstrates we understand it... make meaning. This line of thought that more/faster is better, is fine if you are a computer, but for us human folks, I don't think it holds much merit.

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  12. I think the speed of visual processing is hard to deny. I'd like to see this quantified in some way, and surely that is possible. I do appreciate this discussion (and Dr. Dodge pointing out my need to be critical about statistics like this a few weeks ago via a Twitter comment) because I definitely don't support the sharing of mis-information. I'm going to share this question with a friend who has one of his doctoral degrees in cognitive neuroscience.

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