[ExI] Fwd: neurons

[Giovanni Santostasi]

Neural coding:

Coding schemes[edit<http://en.wikipedia.org/w/index.php?title=Neural_coding&action=edit&section=3>
]

A sequence, or 'train', of spikes may contain information based on
different coding schemes. In motor neurons, for example, the strength at
which an innervated muscle is flexed depends solely on the 'firing rate',
the average number of spikes per unit time (a 'rate code'). At the other
end, a complex 'temporal code <http://en.wikipedia.org/wiki/Temporal_code>'
is based on the precise timing of single spikes. They may be locked to an
external stimulus such as in the auditory
system<http://en.wikipedia.org/wiki/Auditory_system> or
be generated intrinsically by the neural
circuitry.[5]<http://en.wikipedia.org/wiki/Neural_coding#cite_note-Gerstner97-5>

Whether neurons use rate coding or temporal coding is a topic of intense
debate within the neuroscience community, even though there is no clear
definition of what these terms mean.



from wiki


On Tue, May 20, 2014 at 6:00 PM, Giovanni Santostasi
<gsantostasi at gmail.com>wrote:

> Not sure what point you are trying to make. Kaku was trying to use the
> neuron bimodal states (firing or not) to calculate the set of all possible
> combination of states that give rise to thought. It is a simplistic
> assumption.
>
> One could say that what matters is how information is coded and that is
> not completely understood. It can be a combination of things, firing times,
> amplitude modulation, two or more signals arriving at the same time or in a
> precise sequence and so on.
>
> Kaku was doing what physicists often do, approximating a cow with a
> sphere. It is easy in that way to calculate the volume of the cow and it is
> a roughly good approximation.
>
>
>
>
>
>
>
> On Tue, May 20, 2014 at 5:49 PM, William Flynn Wallace <
> foozler83 at gmail.com> wrote:
>
>> OK, so they rest.  I give up.  But do you agree that there are three
>> states of the neuron?
>>
>>
>> On Tue, May 20, 2014 at 5:46 PM, Giovanni Santostasi <
>> gsantostasi at gmail.com> wrote:
>>
>>> In fact, one per second is resting for neurons. That is what happens
>>> when you have slow waves oscillations that corresponds to the deepest state
>>> of sleep.
>>>
>>>
>>> On Tue, May 20, 2014 at 5:23 PM, William Flynn Wallace <
>>> foozler83 at gmail.com> wrote:
>>>
>>>>
>>>>
>>>> ​p.s.  Still, there are three states:  one in which the neuron fires at
>>>> one per second (resting level - no input), one in which it fires faster
>>>> (receiving excitatory input), and one in which it fires slower (receiving
>>>> inhibitory input).​  So, firing or not firing is wrong in the context.
>>>> bill w
>>>>
>>>>
>>>> Well, OK, but the slowest they get is about one spike per second (up to
>>>> 30) without external stimulation.  Not exactly resting.  bill w
>>>>
>>>>
>>>> On Tue, May 20, 2014 at 4:03 PM, Giovanni Santostasi <
>>>> gsantostasi at gmail.com> wrote:
>>>>
>>>>> What you are thinking that neurons are at a particular potential when
>>>>> at rest (about -70 mV). But they are not firing all the time at all. There
>>>>> are times when they are silent.
>>>>>
>>>>>
>>>>> On Tue, May 20, 2014 at 3:42 PM, William Flynn Wallace <
>>>>> foozler83 at gmail.com> wrote:
>>>>>
>>>>>> In The Future on the Mind, by Michio Kaku, he says as follows (facing
>>>>>> page 342):
>>>>>>
>>>>>> "Define complex in terms of the total amount of information that can
>>>>>> be stored.  The closet rival to the brain might be the info contained w/in
>>>>>> our DNA.  Three billion base pairs containing one of four aids, therefore
>>>>>> total amount of info is four to the three billionth power.  The brain can
>>>>>> store much more - one hundred billion neurons, *which can either
>>>>>> fire or not fire*.  Hence there are two raised to the
>>>>>> one-hundred-billionth power initial states of the brain.... the states
>>>>>> change every few milliseconds.  A simple thought may contain  one hundred
>>>>>> generations of neural firings.  Hence there are two raised by one hundred
>>>>>> billion, all raised to the hundredth power possible thoughts contained in
>>>>>> one hundred generations.  Brains are ceaselessly computing.  Therefore the
>>>>>> total number of thoughts possible within N generations is two to the
>>>>>> one-hundred-billionth power, all raised to the Nth power.
>>>>>>
>>>>>> My question concerns the underlined clause:  there are three states
>>>>>> to a neuron:  increasing its rate, decreasing its rate, and staying the
>>>>>> same.  Kaku says that a neuron fires or not.  This seems to say that a
>>>>>> neuron is idle, waiting for stimuli, whereas I think that no neuron ever is
>>>>>> not firing.
>>>>>>
>>>>>> Am I confused again, or is he wrong?  bill w
>>>>>>
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