Initiation of thought processes

[RyanJ]

Hey everyone!

 

We are studying neurons and the CNS in biology right now, a very fascinating subject for me. I understand that certain pathways in the brain gain their information from receptor cells and the like but I came across something I don't understand.

 

I understand the concept of receptor cell process initiation I don't however understand how a thought process can be initiated without such an event. Say for example when you instruct a movement in your hand, there are no receptors that can fire for this because there is no external stimulus so my question too you is: how does this occur?

 

Thanks for the help!

[Mokele]

I dunno if this is applicable, but IIRC, some neurons are continuously, spontaneously firing, and outside stimuli just increase the firing rate. These could serve to sort of 'keep things moving', maybe?

 

Mokele

[RyanJ]

That's a point I never considered and I guess it could be a partial answer. I can't really put the question into words, the best I can do is this:

 

When we think "Move your left arm" we activate the various muscles in the arm to preform a precise movement but how does this impulse actually start? We haven't received any stimulation to take any action and I random neuron firings just won't work for this so something must be sending an impulse but where does this originate and how is the original impulse actually started?

[Quantoman]

may be thought origination is more than just simple communication

between cells...

 

its possible we can't understand thought because of our limited view

of dimension.

 

i think, "thought" in its purist form is energy, and is inter-dimensional.

 

like gentic memory, how is the information transferred from generation

to the next generation? has to be stored somewhere.

 

but where?

 

i know this dont answer anything but, if you think about it all the time

you going to go crazy...muuwwahhhh, ha, ha, aaaa..

 

like me.

 

j/k

 

i just think about this stuff all the time and i am glad others find this

as interesting as i.

[Edtharan]

You can also have situations where Neuron A triggers Neuron B which triggers Neuron C which triggers Neuron A.

 

This could also be used to keep the brain "active".

[RyanJ]

You can also have situations where Neuron A triggers Neuron B which triggers Neuron C which triggers Neuron A.

 

This could also be used to keep the brain "active".

 

This is also true but there must be some initiation too make a neuron fire, simple put - if there is no sensory neuron sending the original impulse too the brain to do something then what initiates the neuron in the brain that causes movement without direct stimulus?

[SkepticLance]

Ryan asked :

 

Say for example when you instruct a movement in your hand, there are no receptors that can fire for this because there is no external stimulus so my question too you is: how does this occur?

 

In a real sense, you asked the wrong question. We know the immediate answer to your query as above. The initiation is internal. A process in your brain results in a nervous signal travelling down to your hand to instruct the movement.

 

The real question is : How does the brain initiate action?

Answer, no-one really knows, but it is bloody complicated!

[Glider]

Say for example when you instruct a movement in your hand, there are no receptors that can fire for this because there is no external stimulus so my question too you is: how does this occur?

 

Thanks for the help!

There is a stimulus. It is the percieved need to move your hand. This can come from outside, for example, when you percieve an object which generates the need to reach for or grasp it. Or it can be internal, for example discomfort at staying in the same position, requiring a change (why we turn in our sleep).

 

There will always be a stimulus.

[RyanJ]

@SkepticLance: Yes, that is the question I intended too ask. So the answer is we don't know how this actually occurs? There must be some form of initation I guess, I just can't work out what it would be

 

@Glider: I didn't think of it that way but in what way does this actually initate a response? There must be a deciding factor that determines when this stimulus will be used to initiate a response such as moving your hand to take hold of somehting. We see things all the time and yet we only actually reach out to grab something when we "want too".

[Glider]

That's true, but the initial urge to reach out and grasp is initiated simply by the perception of an object that evokes an 'approach response' (positive affect - approach motivation). Some objects evoke the opposite (a negative affect - avoidance motivation), in which case, the initial urge will be to withdraw from it.

 

This is a very basic response which occurs preattentively (in the limbic brain) and is generated simply by the perception of such objects (see for example Dijksterhuis, Bargh & Miedema, 2000).

 

Whether or not we carry out the urge to grasp an object is moderated by higher cognitive processes and will depend on higher constructs such as social context (e.g. does it belong to someone else? Will there be negative consequences if I touch it?).

 

Both of these simple urges are adaptive to the species and, equally adaptive is the fact that the urge to withdraw is subject to less higher processing (which moderates the basic urge with the 'appropriate' response). This is why people will flinch away from things like snakes and spiders entirely automatically.

 

Refence:

 

Dijksterhuis, A., Bargh, J. A., & Miedema, J. (2000). Of men and mackerels: Attention, subjective experience, and automatic social behavior. In H. Bless & J. P. Forgas (Eds.), The message within: The role of subjective experience in social cognition and behavior (pp. 37-51). Philadelphia: Psychology Press/Taylor & Francis.

[Edtharan]

This is also true but there must be some initiation too make a neuron fire, simple put - if there is no sensory neuron sending the original impulse too the brain to do something then what initiates the neuron in the brain that causes movement without direct stimulus?

neurons don't just "fire" because another neuron fires. They fire because the levels of neurotransmitters at the synapse reaches a certain threshold.

 

Neurotransmitters can be produced by other cells than neurons, so the build up form these cells could be the stimulus to trigger the first neuron to fire.

 

Once you have that first neuron firing, it can cause others to fire, and so on, in a cascade. Some of these neurons will form a loop and so keep the system active. Also, even without the brain active, we encounter sensory stimulus, even in the womb. These sensory stimuli could also give this "first spark" needed to create the activity in the brain.

 

For either of these situations to occur, the brain doesn't even need to be fully developed. Just have enough neurons to form at least 1 loop. When new neurons are formed, these can then just link up to that loop and the activity spreads.

 

This "theory" also makes a prediction. If the brain is starved of oxygen for a period of time, then the neurons will exhaust their oxygen supply and stop being able to fire. So over a period of time without oxygen, these loops and other self sustaining patterns will fail. If it is these patterns that drive the internals of the brain, then as these fail the brain will fail too. Also this means that once these loops fail, it will be difficult to restart them (especially if the timing of them is important).

 

The might be able to be restarted, by it might produce a different pattern or not all of them will reactivate leading to functional loss.

 

of course this is just a theory, and an untested one at that. But it does make testable predictions, so it could be tested.

[RyanJ]

Interesting, thanks everyone! I think this requires more research on my part too. Thanks for all your contributions