What are memories stored on?

[rturner76]

Obviously memories are stored in the brain. What I was wondering is are they stored in a bit of brain tissue, chemicals, or electric impulses? What is the actual format in which memory is kept secure for later recall? The only biology I know about showed they know about where some memories are stored but not the physical structure of a memory. These kinds of questions are coming to mind as my uncle struggles with vascular dementia.

 

[gym_class_hero]

.

 

[essentialsaltes]

As I understand it, memories are 'stored' not exactly in a single place or as a physical marker, but in a more distributed way, as a pattern of the firing of linked neurons.

Individual neurons can take part in multiple patterns of firing, so they can contribute to multiple memories.

When a memory is evoked, the pattern has been activated by some stimulus, and the neurons fire in that pattern. We can even see individual neurons taking part in this firing. In a famous example, the pattern for remembering the actress Halle Berry could be activated by showing a person a picture of her, a drawing of her, or a sign with the letters HALLE BERRY. And this was seen in the firing activity of a particular neuron. But that neuron may have also taken part in other patterns.

"In a third subject, a neuron in the left anterior hippocampus responded to pictures of the landmark Sydney Opera House and Baha'í Temple, and also to the letter string "Sydney Opera," but not to other letter strings, such as "Eiffel Tower.""

So that one cell responded to a couple different specific famous landmarks, but not all famous landmarks.

So it looks to me that memories are different patterns of neurons firing, and these groups of neurons overlap with lots of other patterns.

 

[rturner76]

As I understand it, memories are 'stored' not exactly in a single place or as a physical marker, but in a more distributed way, as a pattern of the firing of linked neurons.

Individual neurons can take part in multiple patterns of firing, so they can contribute to multiple memories.

When a memory is evoked, the pattern has been activated by some stimulus, and the neurons fire in that pattern. We can even see individual neurons taking part in this firing. In a famous example, the pattern for remembering the actress Halle Berry could be activated by showing a person a picture of her, a drawing of her, or a sign with the letters HALLE BERRY. And this was seen in the firing activity of a particular neuron. But that neuron may have also taken part in other patterns.

"In a third subject, a neuron in the left anterior hippocampus responded to pictures of the landmark Sydney Opera House and Baha'í Temple, and also to the letter string "Sydney Opera," but not to other letter strings, such as "Eiffel Tower.""

So that one cell responded to a couple different specific famous landmarks, but not all famous landmarks.

So it looks to me that memories are different patterns of neurons firing, and these groups of neurons overlap with lots of other patterns.

So I guess what I'm getting at then is in that situation, where is the information that tells your brain which pathways to follow? When the memory is activated, the electricity travels through neurons via dendrites and axon correct? Do you think the Axon Hillock could store the information that is sent through the axon and activates the memory neuron firing sequence that shows your mind's eye the memory?

Does the question make sense?

 

[essentialsaltes]

So I guess what I'm getting at then is in that situation, where is the information that tells your brain which pathways to follow? When the memory is activated, the electricity travels through neurons via dendrites and axon correct? Do you think the Axon Hillock could store the information that is sent through the axon and activates the memory neuron firing sequence that shows your mind's eye the memory?

Does the question make sense?

Again, I'm not an expert, and this is all on the edge (I think) of what the experts understand. But the individual cells are 'trained' to fire at certain rates based on all the synaptic inputs that come into them over their lifetime. That, if anywhere, is where the 'information' is. All the individual axons can do is fire and not fire. And based on the inputs they receive, they either increase or decrease the frequency of firing. But just as a bunch of 0's and 1's can encode any message for a computer, these firings of cells can encode any message. Some particular combination of 0's and 1's means "5" or "b" to a computer, and the connection between a binary number and its meaning is arbitrary, some pattern of firing means "Halle Berry" to a person.

The whole system is frightfully complicated. Some chain of processes like some enormous multidimensional pachinko machine will take an image of Halle Berry presented to your eyeballs, and set off a chain of reaction that ultimately sets off the Halle Berry pattern.

 

[Radrook]

The whole system is frightfully complicated.

But not frightfully complicated enough to conclude a designer of course.

 

[Ana the Ist]

But not frightfully complicated enough to conclude a designer of course.

No.

 

[Radrook]

No.

Very irrationally typical!
Brain (Human Anatomy): Picture, Function, Parts, Conditions, and More

 

[Rajni]

One aspect of memory retrieval that I've found intriguing (and at times annoying) from back in my high-school days is how hard it was to conjure up an image of someone I had a crush on as compared to the image of anyone else in my life. I'd totally recognize them if I ran into them somewhere, but if I tried to recall their face later on, it wouldn't be with the same clarity as that of my neighbor, teacher, family member, etc. But if I was in that midway point between wakefulness and sleep and I tried to recall the face, then it would not only be very clear, it would virtually be 3-D.

The brain blows my mind sometimes.

-

 

[essentialsaltes]

But not frightfully complicated enough to conclude a designer of course.

No. The image I posted has maybe 20-25 cells in it. Your brain has about 100 billion neurons. And the number of connections between them is much much larger. This is complicated, but I see no evidence of intelligent design.

 

[FrumiousBandersnatch]

So I guess what I'm getting at then is in that situation, where is the information that tells your brain which pathways to follow? When the memory is activated, the electricity travels through neurons via dendrites and axon correct? Do you think the Axon Hillock could store the information that is sent through the axon and activates the memory neuron firing sequence that shows your mind's eye the memory?

The axon allows the cell to signal to other cells. The dendrites receive signals from other cells. When neurons fire in a particular pattern, it strengthens that pattern by making the synapses (the connections between the axons & dendrites) bigger, and causing more connections to grow between the cells ('neurons that fire together wire together' - Hebb's Axiom). The basic patterns of connections are established during early development and extended or pruned away over time.

I don't know there's any evidence of the axon hillock storing particular information long term - it's involved with the switching properties of the neuron; when signals come in from the dendrites, different neurons will behave in different ways - some will wait until a certain number of signals have been received before firing, some will change their rate of firing depending on the number of signals being received, and so-on. The axon hillock is where the the inputs are summed up and triggering of the output signal takes place. I don't see how any one neuron could usefully hold any specific information other than its switching behaviour; where would it come from? how could it be used? The single neuron that fires when Halle Berry is recognised doesn't itself recognise Halle Berry, it just happens to be a part of the Halle Berry activity pattern that isn't shared by any other patterns.

 

[rturner76]

The axon allows the cell to signal to other cells. The dendrites receive signals from other cells. When neurons fire in a particular pattern, it strengthens that pattern by making the synapses (the connections between the axons & dendrites) bigger, and causing more connections to grow between the cells ('neurons that fire together wire together' - Hebb's Axiom). The basic patterns of connections are established during early development and extended or pruned away over time.

I don't know there's any evidence of the axon hillock storing particular information long term - it's involved with the switching properties of the neuron; when signals come in from the dendrites, different neurons will behave in different ways - some will wait until a certain number of signals have been received before firing, some will change their rate of firing depending on the number of signals being received, and so-on. The axon hillock is where the the inputs are summed up and triggering of the output signal takes place. I don't see how any one neuron could usefully hold any specific information other than its switching behaviour; where would it come from? how could it be used? The single neuron that fires when Halle Berry is recognised doesn't itself recognise Halle Berry, it just happens to be a part of the Halle Berry activity pattern that isn't shared by any other patterns.

I think I'm following somewhat, please forgive my ignorance on this subject. The memory then seems to be the pattern of electrical impulses that is created the first time Halle Berry is seen and the memory is made. I get that. Now what mechanism ques up that sequence of electrical impulses when the guy brings to mind recognizes Halle Berry?

 

[juvenissun]

As I understand it, memories are 'stored' not exactly in a single place or as a physical marker, but in a more distributed way, as a pattern of the firing of linked neurons.

Individual neurons can take part in multiple patterns of firing, so they can contribute to multiple memories.

When a memory is evoked, the pattern has been activated by some stimulus, and the neurons fire in that pattern. We can even see individual neurons taking part in this firing. In a famous example, the pattern for remembering the actress Halle Berry could be activated by showing a person a picture of her, a drawing of her, or a sign with the letters HALLE BERRY. And this was seen in the firing activity of a particular neuron. But that neuron may have also taken part in other patterns.

"In a third subject, a neuron in the left anterior hippocampus responded to pictures of the landmark Sydney Opera House and Baha'í Temple, and also to the letter string "Sydney Opera," but not to other letter strings, such as "Eiffel Tower.""

So that one cell responded to a couple different specific famous landmarks, but not all famous landmarks.

So it looks to me that memories are different patterns of neurons firing, and these groups of neurons overlap with lots of other patterns.

So, if we both are to remember a phone number, then the firing neuron pattern in my brain could be very different from that in your brain. Right?

Even so, we are not really answer the question. There must be a control mechanism to fire the neuron pattern, where is that mechanism be stored? We forget things. That means the controlling mechanism is lost. What is exactly lost?

 

[juvenissun]

No. The image I posted has maybe 20-25 cells in it. Your brain has about 100 billion neurons. And the number of connections between them is much much larger. This is complicated, but I see no evidence of intelligent design.

This is an excellent example of a so-called "evidence". We are looking at the same thing. It is an evidence to me, but is not an evidence to you.

One of us must be "blind" in mind.

 

[juvenissun]

The axon allows the cell to signal to other cells. The dendrites receive signals from other cells. When neurons fire in a particular pattern, it strengthens that pattern by making the synapses (the connections between the axons & dendrites) bigger, and causing more connections to grow between the cells ('neurons that fire together wire together' - Hebb's Axiom). The basic patterns of connections are established during early development and extended or pruned away over time.

I don't know there's any evidence of the axon hillock storing particular information long term - it's involved with the switching properties of the neuron; when signals come in from the dendrites, different neurons will behave in different ways - some will wait until a certain number of signals have been received before firing, some will change their rate of firing depending on the number of signals being received, and so-on. The axon hillock is where the the inputs are summed up and triggering of the output signal takes place. I don't see how any one neuron could usefully hold any specific information other than its switching behaviour; where would it come from? how could it be used? The single neuron that fires when Halle Berry is recognised doesn't itself recognise Halle Berry, it just happens to be a part of the Halle Berry activity pattern that isn't shared by any other patterns.

What does a "signal" look like when it triggered a memory neuron pattern? Could it be "one" chemical? How do we revoke that chemical? Our brain brings up the image of Halle Berry by a signal of image, sound, word, etc. Do these different methods make the same kind of "signal"?

 

[juvenissun]

The more we remember, the more creative we would be.
Now, how would one neuron firing pattern interact with the other ones and create a new pattern which we never have before?
Would it be true that the larger the brain, the higher the capacity of memory and the higher the ability of creation?

Believe. You must believe.

 

[essentialsaltes]

So, if we both are to remember a phone number, then the firing neuron pattern in my brain could be very different from that in your brain. Right?

Yes.

Even so, we are not really answer the question. There must be a control mechanism to fire the neuron pattern, where is that mechanism be stored?

No, this is a subtle, but very real, mistake. If some pattern is the pattern that recognizes Halle Berry, there is no previous system that has already identified Halle Berry to 'control' the Halle Berry pattern. There is no point in activating the Halle Berry identifying system, if the 'controller' has already somehow identified Halle Berry.

For simpler systems, we do understand how cells in the vision system react to movement or lines. No control system has to tell them to see a line. The input from the retinas is all that is needed. Similarly, the input of Halle Berry's face or name ultimately leads to the activation of the Halle Berry system, and that is where the recognition happens.

 

[Ana the Ist]

Very irrationally typical!
Brain (Human Anatomy): Picture, Function, Parts, Conditions, and More

Nothing irrational about it...

"Brain is complex=god" is not a logical argument.

First of all, you'd need to explain why there cannot be complexity without a "designer"....which none of you ever do.

Then you'd need to explain why your unbelievably complex god doesn't need a creator...you know, so you aren't committing another logical fallacy.

 

[Ana the Ist]

This is an excellent example of a so-called "evidence". We are looking at the same thing. It is an evidence to me, but is not an evidence to you.

One of us must be "blind" in mind.

Or one of us wants to believe so badly that they "see evidence" where it doesn't exist.

 

[Radrook]

Nothing irrational about it...

"Brain is complex=god" is not a logical argument.

First of all, you'd need to explain why there cannot be complexity without a "designer"....which none of you ever do.

Then you'd need to explain why your unbelievably complex god doesn't need a creator...you know, so you aren't committing another logical fallacy.

You are misrepresenting what I mean.