forward foot-placement instinct

I've noticed this effect as well, usually when running/walking over an obstacle. You can
instinctively get your feet into the correct stride a few steps before. But I've always attributed
this to learned behaviour and experience rather than some evolutionary trait.

"Roger" <[email hidden]> wrote in message "]news:[email hidden]...

Quoted message said:

Years ago I noticed that 5 to 10 steps ahead of my current jogging or running position - I could
predict instinctively whether footfalls would

be

Quoted message said:

"on" or "off" an object, like a limb, debris, or sidewalk edge, and alter

my

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pace to miss that object 15 to 20 yards ahead. I assumed at the time this seemingly autonomous -
even magical - skill would have had early

vertebrate

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survival values, both for quick effective retreat and for rapid and uninterrupted pursuit of
quarry. For lack of a better word, I called it "tracking response". Anyone aware

of

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this phenomenon, or have knowledge or links to it?

"Roger" <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

Years ago I noticed that 5 to 10 steps ahead of my current jogging or running position - I could
predict instinctively whether footfalls would be "on" or "off" an object, like a limb, debris, or
sidewalk edge, and alter my pace to miss that object 15 to 20 yards ahead. I assumed at the time
this seemingly autonomous - even magical - skill would have had early vertebrate survival values,
both for quick effective retreat and for rapid and uninterrupted pursuit of quarry. For lack of a
better word, I called it "tracking response". Anyone aware of this phenomenon, or have knowledge
or links to it?

Hi Roger, personally I think this is a standard role of the brain - to "predict", or form hypotheses
about, what is going to happen in the surrounding environment a few seconds into the future. You do
this all the time when walking down the sidewalk, driving your car in traffic, skiing down a mogul
field, etc - plotting a course, etc. And I would imagine that you get better at it, in regards to
activities which you engage in on a routine basis. Obviously this ability is present a long way back
in evolution for animals which run and pursue, such as lions and zebras.

Along these lines, one of Daniel Dennett's recent themes [in Freedom Evolves, I believe] is that the
purpose of the brain is to "predict future". Predictions, in the narrow sense of the word -
apparently not meaning fortune-telling.

I recently started reading a book called "The Brain's Sense of Movement" by Alain Berthoz, pub 2000
[avail Barnes+Noble]. AB is a french neurophysiologist who has been studying the mechanisms of eye
movements, etc, for 30 years or so. I haven't gotten far into the book as yet, but it looks quite
interesting. He starts the book as follows:

"This book is a reflection on how the brain works, based on the idea that the brain is used to
predict the future, to anticipate the consequences of action (its own or that of others), and to
save time. To this end, very diverse biological mechanisms developed over the course of evolution
... these mechanisms endowed the brain with internal models of the world and of the body - not just
any models, but models that reflect the laws of nature, the Umwelt of each species ... The brain is
not a reactive machine; it is a proactive machine that investigates the world ..."

- dan michaels
======================

"Pete" <[email hidden]> wrote in message

Quoted message said:

I've noticed this effect as well, usually when running/walking over an obstacle. You can
instinctively get your feet into the correct stride a few steps before. But I've always attributed
this to learned behaviour and experience rather than some evolutionary trait.

The two aren't incompatible. There would be a selective pressure for humans who could place their
feet around obstacles without breaking stride. It would probably be quite a large pressure as
running speed is critical in catching prey and in evading danger. However evolution doesn't care how
this is achieved, either by some specialised section of the brain or as general-purpose learning.
One thing you are asking is, given two populations, one which lives in the African forest and does a
lot of running around unmade tracks, and another which lives in a Western city and is hardly ever
exposed to a non-metalled surface, how much better would the Africans be at an obstacle dodging
test? Another thing you are asking, which is much harder to answer, is, are the same processes used
in learning to dodge obstacles with your feet as, say, to control the clutch of a car, or are the
two tasks learnt differently in some way?

dan michaels <[email hidden]> wrote:

: Along these lines, one of Daniel Dennett's recent themes [in Freedom Evolves, I believe] is that
: the purpose of the brain is to "predict future". Predictions, in the narrow sense of the word -
: apparently not meaning fortune-telling.

It needs to do substantially more that just that! ;-)

Predictions are useless if they are not followed up with actions.

Determining which actions are likely to be appropriate in response to future conditions and
initiating them is also the brain's job.
--
__________
|im |yler timtyler.orgtimtyler.orgOpen ↗ [email hidden]

Quoted message said:

Obviously this ability is present a long way back in evolution for animals which run and pursue,
such as lions>and

zebras.

Zebras? Persue? Hmmmm. Well, anyhow as far as lions and other predators are concerned I think it was
Scientific American not long ago had a nice article pointing out that for a predator to be
successful in a pursuit it must match strides with its prey. Quite a feat when you think about it.
Lots of evolution there.

TWINBLUE