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[Neuroscience] Re: Brain and awarness

Glen M. Sizemore gmsizemore2 at yahoo.com
Thu Mar 30 15:32:42 EST 2006


<feedbackdroids at yahoo.com> wrote in message 
news:1143745636.214109.99560 at i39g2000cwa.googlegroups.com...
>
> Glen M. Sizemore wrote:
>> Ohhhhh! I see. We couldn't just say that the person responds, in part, to
>> the pitcher's motion. A copy of the pitcher's motion has to get inside 
>> the
>> brain where the homunculus can see it. Right Dan?
>>
>>
>
>
> A single-celled protozoan has a "lightspot" [actually, an aggregation
> of light-sensitive molecules] on one side right next to its flagellum
> base. Apparently they cause production of some chemical which
> stimulates the flagellum to move. Do you think the protozoan could hit
> a baseball pitch? If not, why not?
>
> Hint: it doesn't have the necessary "internal" sensory and motor
> mechanisms.

This has nothing to do with the issue of whether or not responding to the 
world is "really" responding to an inner copy of the world. The fact is, 
even if there is an inner copy, there must be some place where the copying 
stops and the responding begins. That is, it MUST be possible for there to 
be some psychologically relevant apparatus that "utilizes the information" 
without further copying.  This suggests that the "information utilization 
apparatus" might be the brain, and the "information" located in the world. 
That is, we respond to the world, and our physiology mediates that function.




>
>
>
>>
>> <feedbackdroids at yahoo.com> wrote in message
>> news:1143741168.024219.135950 at e56g2000cwe.googlegroups.com...
>> >
>> > tehgabriel at web.de wrote:
>> >> Hi!
>> >> The average reaction time of humans is around 1 s (e.g. time one needs
>> >> to initiate braking his car after the perception of a red light).
>> >> Training and expectation (you know that a certain event will happen)
>> >> can lower the reaction time to 0.1 to 0.4 s. So, definitivley below 
>> >> 0.5
>> >> s.
>> >>
>> >> Concerning your example with the pitcher (I am not familiar with
>> >> baseball) i would assume what enables one to hit the ball properly is
>> >> the ability to predict a chain of subsequent events. One can predict
>> >> (note that precision of prediction increases with 
>> >> experience/practise):
>> >> how the pitcher will move  =>  at which point the ball will leave his
>> >> hand  =>  the way of the ball
>> >>
>> >> Regards,
>> >> Thomas
>> >>
>> >
>> >
>> > This is exactly correct. Nothing in cognition [ala brain operation]
>> > simply starts and stops at specific times. Rather all operations are
>> > performed in the context of "on-going" foreground and background
>> > activity. In the end, I think, people will come to realize that this is
>> > the key issue involved in the correct interpretation of Libet's
>> > experiments, too.
>> >
>> > Eg, if you look at the P300 alerting wave, it doesn't simply exist at
>> > one point in time, with a clearcut beginning and end. Rather, it builds
>> > up steadily over a 100-200 msec time span, and than wanes over an
>> > additional 500-800 msec. It just happens to "peak" at about 300 msec.
>> > What this indicates is that neural activity persists in internal neural
>> > feedback loops for much longer than simple 1-to-1 transmission between
>> > neurons, which will take only 10-20 msec. For activity to last upwards
>> > to 800-msec, it must involve multiple passes around the internal loops,
>> > while first more and then less neural tissue is being recruited into
>> > the process.
>> >
>> > All of this internal activity is taking place within the brain during
>> > any cognitive or behavioral task. This is continually performed
>> > internally while the external events are taking place. As the pitcher
>> > gets ready to throw, winds up, stretches, and then releases the ball,
>> > all of these external activities are reflected by internal brain
>> > operations in the batter in preparation to hit the ball. Each step
>> > involves updating internal predictions of where the ball will go.
>> > Without these internal predictions, the batter couldn't possibly hit
>> > the ball. Every nuance of the pitcher's activity will change the
>> > internal predictions in some way, before the pitch. After the ball is
>> > pitched, its trajectory will further modify the internal predictions,
>> > and the movement of the muscles to hit the ball. Finally, batters can
>> > modify the bat trajectories even as they swing, based upon where they
>> > predict the ball will be going as the flight ensues.
>> >
>> > The best pitchers either throw the ball so fast that the batter's
>> > predictive [and probably motor] machinery cannot keep up, or else are
>> > able to throw balls with so much spin that the balls suddenly change
>> > course too late for the batters to be able to respond. Eg, balls that
>> > come relatively straight but then suddenly sink over the plate at the
>> > last instant, as the spin effects build up. Spin effects are pretty
>> > cool. When I bowled the 3 or 4 times I ever bowled, I had a wicked hook
>> > on the ball. It would fly down the edge of the lane, first relatively
>> > straight due to forward momentum, and then at the last instant curve
>> > around and into the pins, and spin took over from forward momentum.
>> > Neat.
>> >
>> > For a 100 MPH pitch [the fastest recorded], and 90' to the plate, it
>> > only takes about 0.6 sec for the ball to travel the distance, so
>> > without an entire spectrum of one-after-another perceptual cues and
>> > especially internal predictive mechanisms, the batter could never ever
>> > hit the ball.
>> >
> 




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