Thinking with your brain

[MargeB]

Is thinking made up of the activity of neurons in your head and nothing more?

[Tim Baxter]

I would say yes but there are those amongst us who would attribute thought to a different plane of existence!

[mikeyp]

Heh, I can see this question proving popular. I would say no. We really know very little about the brain to make such a decision though. Leave it a few years!

[jake-the-peg]

Although thinking is due to neuron activity - you can see this clearly in brain scanners, it is a very complex process which we don't fully understand.

The brain seems to have a limited ability to reroute and use different areas for different things. 

I have a nephew who was born profoundly brain damaged, there should be no way that he should be able to see anything at all, there is simply no path to the vision centres of the brain. Yet he has some light and dark perception and some movement.

There are people walking around with large areas of their brain missing who are functioning perfectly well.

It doesn't seem to work in a simplistic computer type way where one neuron represents one bit of information

If you want to show that thinking is not soley due to neurons you'd need to find an example of someone with a fully healthy brain who is unable to think.  

[mikeyp]

Agreed. I wonder though jake, since you seem to know a bit about this, during my a-level biology we were taught about the structure of neurones. What struck me was that there seems to be no way for a neurone to distinguish between two messages. For example, suppose a neurone has x dendrites (here). If it recieves an message via any one of them, the action potential will still move down the axon. And theoretically be sent to all other neurones connected to it. If neurones can't interpret messages, and can't even send them to a particular place. What's going on?! Apparently my teacher couldn't answer and 3 years later i'm still wondering.

[jake-the-peg]

I'm no expert but my understanding is that neurons tend to have other inhibitory neurons connected to their dendrites these can either block or allow through the signal.

I think you've got it in reverse. It's not that the neuron switches a signal to one of a number of other neurons rather that the receptibility of a particular neuron from another particular neuron can be enabled and disabled.

Have a look here - if this doesn't help then I'm officially out of my depth.

www.bris.ac.uk/synaptic/public/basics_ch1_3.html 

[MargeB]

You can have mutual inhibition between neurons.

The network of neurons codes for 'information', you can achieve this even if individual neurons were 'all or nothing', which in any event they are not. See 'Sense and the single neuron', by Parker and Newsome, available on web as pdf. It's easily the best intro to cognitive neuroscience. It don't have the answer to my question though. Although it does suggest that the complexity of human psychological activity cannot be reduced to the coding inherent in the neurons that seem to underpin it.

[Bob A Job]

It has to be said that we men do think with something other than our brains sometimes. But seriously, I believe its all 'up there' in our brains.

Pondor this, There are more possible nueron connections in the human brain than there are stars in the universe.

[stevie21]

Very often, thinking involves scratching your chin so that's at least arm, hand and chin involved for a start.

What on earth else would be involved in thinking other than your brain?

[MargeB]

Well, several million people in the UK believe that there is something spiritual involved, I do not really share this belief.

People experience 'thought' or memories of it even when their brains are dead.

Science shows that the activity of neurons cannot contain all of the information needed for the process which they support.

So.........

[Peter Pedant]

I am sorry Marge I have to take issue with two of your statements:

People do NOT experience thought when their brains are dead. They're dead , and cant tell us about it - they're dead. No-one who has fulfilled the british brain death criteria has recovered, and before you say Karen Quinlan, Jennett before he died - he has not been talking to me since his death - said that he had been asked to review her notes and she did not fulfil the criteria.

and secondly - science does NOT show that all activity - all thought I agree some people think it does

Other than that, I didnt think there was much to carp about in your posting.....

PP

[stevie21]

MargeB, that's a bit of a sweeping statement :
"Science shows that the activity of neurons cannot contain all of the information needed for the process which they support."

Science can tell us comparatively very little about how the brain works. With your education you should be one of the first to offer that conclusion. Have you forgotten what you learned in your degree?

[MargeB]

Compared to what? Geology? Astrophysics? Neuroscience does say a lot of stuff. However I don't really understand what you are saying. Are you saying 'Science can tell us comparatively very little about how the brain works' therefore I am wrong in my statement '"Science shows that the activity of neurons cannot contain all of the information needed for the process which they support." '

[jake-the-peg]

Marge, where do yu get the information from that science shows that neuron activity cannot contain all the information needed for the prcoesses that they support?

It sounds a bit like a "bumblebees can't fly" piece but I'd like to look at the data before just dismissing it.

[mikeyp]

You surely just learn this stuff? I was taught that a neuron will recieve a signal from the synapse at the end of one of it's dendrites. This will create an action potential (if the signal is above some threshold). An action potential is just the movement of potassium and sodium ions across the cell membrane. It seems quite clear to me that this alone is not responsible for conciousness. As of yet neuroscientists don't seem to have come up with a reasonable theory as to why we can think with just this in our heads. The argument seems to be that there so many connections in the brain it just works? What I wonder is if you took many wires and connected them together in the same way, would we get a concious computer? I think no, they're just wires after all.

[jake-the-peg]

It's more than just that though isn't it - The neurons grow and make new connections so when one group (or pattern or whatever represents a concept) is stimulated followed by another. There is the capacity for neurons to make new connections and reinforce that connection.

A bunch of wires in a computer can't do that in anything like the way the computer does.

Butas I said if thought is more than that it should be possible to find instances where that additional process has broken and find cases with people with healthy brains that cannot think.

Autism might be an interesting starting point - Although suffers clearly can think I believe there is no known physiological damage that accounts for it. 

[MargeB]

I'm working on an answer to the other questions, (I believe my link does contain information on the information carried in neuronal activity being greater than the sum of its parts, and Southampton Uni work on 'mental activity' in the brain dead.

The 'autism' one popped out at me meantime. People with autism spectrum disorders demonstrate increased activity in mirror neurons, which fire during an action as well as the observation of that action.

[Tim Baxter]

Just a humble suggestion but aren't all theories the 'best fit model' which may not exactly be the truth but will do until we get a closer 'fit' model (like light being a 'waveical').  If this is so and one person has a model which has been structured or learned differently from someone else's then there's no point in carrying on a discussion until the two (or more)differing models fit more closely.  Oh er, is that the whole point of discussion, (Hides head in sand!)

[stevie21]

MargeB, yes, I am saying what you think with your "are you saying...." statement. If we know very little of how the brain works, how can we know of what it isn't capable of? (or even is)

mikeyp, this isn't really a direct answer to your question/statement but if I had one bloke (Gordon Ramsey or other famous chef) and compared him to the best chemist on the earth, the latter wouldn't make a better dinner just because he was able to explain what was happening at cell/molecular level. Reductionism isn't always the best way of looking at *everything*.
Until you have a doctorate in neuroscience you will excuse my lack of enthusiasm for your theories of the mind and brain.

I'm afraid I offer no answers. The best minds on the planet don't understand how all of this works so I'm in no position to conclusively state one "fact" or another about what the right answer is.

[mikeyp]

Heh, fair enough. Let's face it, I have no idea. I will however, cling on to my loopy ideas until someone can convince me otherwise. Long live dualism!

[Trillipse]

gilbert ryle's "a concept of mind" is a good one on this "topic"... at least, i thought so.