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Neurohacking - Tutorials
Written by NHA   
Sunday, 05 February 2012 12:46
Article Index
Neurohacking Tutorial 8 - Imagination, Memory and Prediction
Neuroanatomy of Memory - Structure and Function
Everywhere and Nowhere
How Memories are Made
What Happens if Things Go Wrong?
Core Skills for Memory Health and Improvement
Imagination and Prediction
NHA Guide to Methods & Technology
The Most Important Bits To Remember
Hacks & Exercices
Notes, References & Answers
All Pages


 

 

How Memories are Made

 

memory at cellular level

Once a cell has ‘made a move’ or the series of moves involved in a process, it will ‘remember’ it as a spatio-temporal pattern of sensation within itself; like the ordered steps of a dance.

Researchers [70] found that just one brain cell is capable of holding these fleeting memories vital for our everyday life. The specific signal that enables cells to do this has the unwieldy name “metabotropic glutamate transmission” (but you don’t need to remember terms like that in order to do NH.) All we need to know is that this transmission holds moment-to-moment information. The cell’s receptor, when switched on, starts an internal signal system that holds the "memory" of the cell’s pattern of behavior in place.

Understanding your brain's ability to retain short-term information in this way is important in understanding the laying down of longer-term memories –(If you've got no short term memory, you've got no way of making longer-term memories.)

All memory at cellular level consists only of these patterns –the spatio-temporal sets of movements that were made inside the cell, in order to initiate the processes and release resources (for example gene products, proteins, immune system triggering) required for the organism to respond to the input signals. The process is recorded as a ‘dance’, and new input sufficiently similar to old will trigger the familiar patterns. This is what is known as ‘muscular memory or sensorimotor memory, on the micro level. On the behavioral level physically it is the multiplicity of millions of these cell responses that results in our own series of bodily movements, perhaps for riding a bicycle or eating food, or moving our eyes so that we can read this tutorial. Our responses are ‘automatic’ and we don’t have to concentrate on them once we have learned. All the work is done unconsciously. But this is just brain + body –so what about mind? How do cells perceive at the mental level of thoughts, ideas, concepts and abstractions?

 

The beginnings of memory

To recap on perception: The patterns of encoded cell responses caused by input trigger the formation of percepts, which we interpret by comparison against our known concepts.

Long term memory is our database of known concepts or 'bits of meaning'.

Obviously when we are first born, we have a very small database of memories -our core concepts are primal images with broad spectrum associations, and these are used exactly as all memories coming after -they are a database of known concepts against which to compare input.

Most animals have such presets or hard wired memories. A newborn chicken has the image of a seed shape as one of its core concepts, associated with food and the animal behavior of food gathering. Any percept that has enough points of similarity to the core seed concept (for example small beads, ball bearings or colored dots) will be pecked at, because the details are only filled in later by trial and error, success and failure, like and dislike.

Our own database for the core concept 'matter' (N1) contains this hard wired image:

 

 

This image is associated with the proportions of a smiling human face and the animal behavior of bonding with allies. It is one of six initial concepts that act as biological triggers which, when met with their complementary percepts from the outside, triggers gene transcription to bring all of our senses fully online.

These core images are almost like 'boxes that biology has to tick' before the genome gets the message that it's safe to activate sensory systems.

When all boxes are ticked, human newborns find their systems flooded with oxytocin, serotonin and endorphins that destroy all the stress hormones that were needed for physical birth, we experience our first relaxation response and development goes right ahead calibrating the details of those new sensory systems. After a good sleep to defrag all these new associations it gets straight down to the exciting business of growth, exploration, play and development. Intelligence begins to unfold. Effectively from that point on we can use known memory plus imagination for both perception and making new memory. In ideal circumstances (where carers' priority is to understand what our minds need us to do and help us achieve that), long term memories begin in the first year of life. [28] This is how what we think of as 'our memory' is built from the bottom up.

To enable us to start building associations right away, we are hard wired at birth to recognise any percept that has enough points of similarity to these core images. As soon as the first relevant percept is recognized, it is added to our concept database with all its accompanying extra details, brain connections are growing and biology has signaled the genome to produce the proteins to start calibrating the associated system. This particular one (smiling human face) is vision.

As infants we have no conscious idea it is 'a smiling human face' we are looking for; that sort of detail (conscious awareness) comes later. All we know is that it makes us feel right and that it means all is right with the world; because to biology it means that growth and development can proceed to unfold as planned. Biology has some flexibility in core percept parameters -any face with enough points of similarity will do, but it must be presented within the first 45 minutes after birth for the chemistry of bonding to remove stress hormones before stress becomes chronic (anxiety). The more we recognize the relevant percepts, the more the genome is signalled and the faster stress hormones reduce. If we don't find any percept to match this image within an hour or so of birth, we'll remain blind for at least three months while the system seeks input to reduce anxiety and tries to boot up its systems. Mental development is then out of sync with physical development and it gets harder and harder to catch up with each delay in appropriate input.

Biology trusts the preceding generations' adults' unconscious knowledge to make sure that input is appropriate. In most cases these days culture (skills & knowledge, learning and experience, handed down in bonded relationships) has been replaced by society; an artificial external system that dictates what to do, and in most cases this system has failed humanity in that it mostly results in dysfunctional mentality and a lot of stupid and dangerous behavior, that with increasing numbers may at worst drive humans to extinction and at best transform them into mindless domesticated cattle. There is no future for intelligence in either path.

What we do in NH is supply appropriate input to enable mental development to emerge as intended at any age.

 

Processes of memory

Making new memories follows the learning process.

At this point we are going to extend your mnemonic for the learning cycle to “COMP VC”. Don't worry; there isn't a load more stuff to learn! We are simply separating Practice & Variation, and adding 'Coordination' to close the cycle, because in understanding memory we need to examine more closely the underlying processes involved and making these changes will make them easier to compare. By 'coordination' we mean the ability to creatively interact in the context of the subject of study, the skill being learned, or the type of process being coordinated with the rest of what we already know about reality; it becomes part of our 'big picture', and is incorporated as an updatable (dynamic) permanent memory in our database of known reality.

 

Memory processes: Receiving - perceiving - encoding - consolidation - retrieval - reconsolidation

Learning cycle: Concentration - observation - modelling - practice - variation -coordination

 

Concentration: reception

For new memories to form at all, input must be received and perceived. Comparison of new percepts with known concept images leads to recognition - so far this is the process of ordinary perception using existing memory for comparison, and no new memory is being made. The entorhinal cortex reformats input, and the hippo compares it.

 

Observation: perception

Existing long term memory prepares the neural activity for perception.[31] All perceived input ends up at the hippo, where it's combined into one single experience.[33] These two stages have been amply studied above and in the previous tutorial.

 

Modeling: encoding & weighting

Recognized percepts are encoded (reformatted) and held in short term memory storage (RAM) for further observation & comparison. We call this type of memory RAM because data are stored randomly and not according to association with any location. Weighting is added during this stage as described earlier. This stage is commonly known as memory encoding or registration.

Holding a short term memory requires N3 to communicate with N6 in specific ways using theta waves.[75] Importantly, these oscillations do not occur independently of each other, but synchronize their activity temporarily, and the more synchronized the activity is, the better we can remember the initial image.

Encoding begins with an analog process that automatically associates by location and simply represents one format of input with another, in this case graphics. It's exactly the same process that allows us to represent the color blue with the spoken word 'blue'. We know that the word is not the color; one merely represents by association the concept of the other. The color blue, in fact, is N3's graphic representation of certain wavelengths of light falling on the retina. Our brains do this sort of representation all the time in order to make sense out of input.

In reality, color is not an inherent property of objects; color is an emergent property of the interaction of our minds with the properties of reflected and refracted electromagnetic energy. A creature able to perceive ultra violet or infra red wavelengths of energy gets a quite different image than we do. What's coming into the eyeball is simply energy with a wavelength of roughly 440–490 nm. N3 detects the firing pattern lighting up a concept in the top right hand side of its inner model (which represents N4); the concept is 'blueness'; and N3 projects the graphic color stored at that location of its model onto the inner screen as a representation of what is stored in that exact location in the real N4. Result: you think that's blue you're perceiving now...?

Unseen result: the brain, using the minds own images as input, releases the neurochemicals which the weighting packet on that image triggers; and in this case blood pressure, temperature and heart rate drop slightly and we perceive time as passing more quickly.[35]

Constantly experienced emergent phenomena like color are stored permanently in N3. Blue graphics will be in the upper right hand area of the model because blueness is associated with the core concept 'time' and the location of area N4 (which processes all time related data) in the real world; the upper right area of the brain. The memory concept 'blueness' is stored in N4 because all memories with (conscious or unconscious) time-related associations are stored in N4, and the unconscious mind knows by direct physiological experience that input at 440–490 nm is associated with time perception in circadian rhythms (melanopsin, a photopigment expressed in the inner retina of mammals, mediates nonvisual photoreceptive tasks in circadian regulation in response to blue light).[36]

Time is a core concept, and all things relate back to the core concepts as the mind considers them the most important bits of meaning central to all things in reality, and this is not too surprising an evolutionary conclusion, because as far as we are able to determine through science, they are.

At no point of the process of recognition or recall does N3 think in words, "Oh, that's blue!". No semantics are in effect here; only graphic concepts. N3 simply follows the rule: IF signals flash in any location on this model, THEN project the images stored at those locations".

The concrete physiological process of encoding needs only basic signaling; all N3 has to do is project representations of associated concepts from the correct department, and it knows where everything is already because it has an inner model, on which the firing caused by input leaves a trace pointing straight to the required location in the real brain. When you read the words, 'imagine a real live tiger', the input pattern made by the sound of the words and the shape of the letters fires a 'tracer' on the inner model that points straight to the graphic image of a tiger together with associated behaviors and backgrounds, but N3 doesn't have to think in order to do that. If an input signal points to where a pigment graphic is stored, it just projects it. If there is no stored concept for blueness in N4 (say, because the person is colorblind), N3 will still project the nearest graphic concept to the location of input firing and may represent the color as green or gray.

Weighting has been partly described above. A surge of the neurotransmitters that accompany an ‘important’ experience sparks a series of molecular events that ultimately grows the physical brain and increases our memory store, and the density and type of this surge modulates an event’s weighting in our memory in all future recall.

The amy attaches a chemical packet to ‘tag’ the new picture with transmitter triggers to reproduce the emotional state accompanying the original experience so that we remember that it's important, irrelevant, dangerous or beneficial and associate it with particular networks by reference to core eidetic concepts. This is the ‘weighting’ of memory. If it goes wrong, this process can become pathological, as occurs in Post Traumatic Stress Disorder (PTSD), a condition characterized by persistent, too-vivid memories of traumatic events.

New concepts with enough weighting are held in RAM until it's getting full, at which point we need to sleep so that it can offload and defragment its information.

Defragging is a complex process. Long term memory is contiguous; that is to say every part of long term memory (and every corresponding location on the inner model) stores a tightly-connected continuum of associated concepts, however new concepts are at this stage in RAM, all mixed together unsorted and unfiled. Basically N3 has to move new concepts into permanent storage accurately adjacent to their closest associations, and update its inner model to match this updating of long term memory.

It does this by physically organizing the contents of RAM into the smallest number of contiguous regions the memory fragment coordinates associate with, then reactivating those memories for sampling in the locations analogous to the coordinates on its inner model indicated by the initial input signals.

The inner model is a finite model, but enables us to re-use the same set of categories ad infinitum and the whole ‘chain’ of associations can be represented as a bit pattern that in computing would be called the memory’s ‘address’.

Space and time are always optimized. N3's graphic format is an effective form of compaction for the inner model, where only the basics are needed, interpretation by location is an instant method for translating one type of code into another, and the brain's tidy habit of removing unused data constantly frees up unused resources.

Defragging also keeps synesthetic associations together, as they are often accessed simultaneously or in sequence.

This process needs constant two way communication between N3 and N6, and intermittent contact with other areas of the cortex. And it happens fast. Researchers have shown that, during sleep, the reactivated memories of real-time experiences are processed within the brain as much as six or seven times faster, and the difference shows up sharply in EEG studies.[37]

Current findings support a bidirectional interaction model between the hippocampus and the cortex for memory consolidation.[38]

The order of sleep/consciousness stages occurs as follows: 1, 2, 3, 4, 3, 2, 5(REM), 2, 3, 4, 3, 2, REM etc then 6 (wakefulness) right after the last REM. Humans spend about half their sleep time in stages 2 and 3, and around a quarter in REM sleep.

Stage 1 sleep appears on the EEG as drop-out of beta (15-30 Hz)[47] and alpha (8-12 Hz) and an increase in theta (4-8 Hz) frequencies.

Stage 2 sleep is characterized by sleep spindles—transient runs of rhythmic activity in the 12–15 Hz range (sometimes referred to as the "sigma" band) that have a frontal-central terminal.

Slow oscillations are generated in the neocortex and hippo itself and reflect widespread up and down states of network activity. This 'down state' is a phase of hyperpolarization with neuronal silence, followed by a depolarization phase or 'up state' characterized by intense synaptic activity and neuronal firing as the hippocampus sends little, 100-millisecond bursts of activity to the cortex as much as three times per second.[39] Most of the activity in stage 2 is in the theta 4–8 Hz range.

Stage 3 and 4 sleep are defined by the presence of delta (1- 4 Hz) frequencies and are often referred to collectively as "slow-wave sleep"(SWS). In stage 3, delta waves make up less than 50% of the total wave patterns, while they make up more than 50% in stage 4.

So far everything is non-REM (or "NREM") sleep.

Stage 5 is REM sleep. Hippocampal rhythmic slow activity (RSA or theta) is a distinctive feature of REM sleep of rodents, carnivores, primates and humans.[40]

During REM sleep, intrahippocampal EEG recordings clearly show a theta frequency rhythm accompanied by a decrease of power in the beta range, and the hippocampus shows a generalized tendency to EEG synchronization.

Studies have revealed SWS-related slow oscillations in the hippocampus, as well, that are transiently coordinated with neocortical slow oscillations.[48] This co-ordinated slow wave oscillation may provide a substrate favoring hippocampal-neocortical dialogue for off-line memory consolidation.[49]

Gamma waves now occur between N3 and N6. Ordinarily, gamma waves relate to waking consciousness via the mechanisms for conscious attention, they display during cross-modal sensory processing (synesthesia that combines two different senses, such as sound and sight)[41], and during short term memory matching of recognized objects, sounds, or tactile sensations.

Gamma waves @ 40 Hz also appear in meditation after regular practice.[42]

When sleeping, they indicate visualization (imagination projecting images in the inner model). A wave that appears to originate in the thalamus sweeps the brain from front to back at 40 Hz (40 times per second), drawing different neuronal circuits into synch with percepts and bringing them into the attentional foreground. This synchronization gets the new concepts and the known concepts they relate to oscillating in synchrony, and 'cells that fire together wire together' tells us how concrete connections are joined to embody abstract associations between bits of meaning.

Within the hippocampus, high frequency oscillations known as sharp wave/ripple complexes (SPW-Rs) are associated with synchronous discharge of a large neuronal population in multiple hippocampal sites.[49]

Several studies have since revealed that ensembles of neurons, firing together during a particular behavioral experience, tend to ‘replay’ during the following SWS episode.[50] This activity recorded during sleep or during still wakefulness, is more likely to occur during ripple events. These cells fire together at high frequencies, which should promote Hebbian plasticity, i.e. Long Term Potentiation (LTP).[51]

High order replay of waking activity has been observed in the hippocampus during both SWS and REM sleep [43] reflecting the consolidation of episodic memory traces [44]. Hippocampal reactivations during SWS, correlated with an improvement in spatial memory performance, have been reported also in humans.[44]

In 2009, researchers discovered that the frequency of gamma oscillations routes the flow of information in the hippocampus.[45] A year later, further research showed that successful memory formation can be predicted by the degree of coordination of spike timing relative to the local theta oscillation.[46]

In 2011, neuro-physicists found there is an optimal brain "rhythm," or frequency, for changing synaptic strength. Each synapse is tuned to a different optimal frequency for learning.

The knowledge that a synapse has a preferred frequency for maximal learning led the researchers to compare optimal frequencies based on the location of the synapse on a neuron.

The optimal frequency for inducing synaptic learning changed depending on where the synapse was located. The farther the synapse was from the neuron's cell body, the higher its optimal frequency.

For the best effect, the frequency needs to be perfectly rhythmic; timed at exact intervals. Even at the optimal frequency, if the rhythm was thrown off, synaptic learning was substantially diminished.

Their research also showed that once a synapse learns, its optimal frequency changes. In other words, if the optimal frequency for a new synapse -- one that has not learned anything yet -- was, say, 30 spikes per second, after learning, that same synapse would learn optimally at a lower frequency, say 24 spikes per second.

Thus, learning itself changes the optimal frequency for a synapse.[52]

Research has even shown that spatial & procedural memory benefits from late, REM-rich sleep, whereas declarative memory benefits from early, SWS-rich sleep.[53]

Whenever we become semi-aware of the defragging process, the unconscious mind (in the perceptive equivalent of a source monitoring error) imagines it to be genuine input and attempts to interact with it. The result we call dreaming, and we'll be exploring dreams in greater detail in tutorial 10.

 

Practice: consolidation (storage)

The eventual permanent storage location of any memory segment in the inner model for most accurate association is a matter of trial and error. We assign an initial location from the data currently available and fine-tune it with further interaction. The more familiar we become with something, the more our memories are updated accordingly.

We can see this fine tuning taking place in real life if we compare our first impression memories of a place or person to our memories of them after long experience. The more interaction we get, the more accurate our assessments get of 'where they belong' in our overall associations. It takes practice to get memory categorization perfect.

Like all stages of memory, consolidation requires specific changes in neurochemistry. We start out by placing components of a memory where N3 thinks it probably belongs or might belong in relation to other similar experiences. The neurotransmitter noradrenaline stimulates initial development of local connections in all possible directions.

Every time neural signals fire along associated pathways, those particular pathways are strengthened (frequent users get broadband). The repeated release of neurotransmitters causes gene transcription, and the resulting proteins are sent to build more connections between cells that are firing coincidentally, both within areas and between areas. Local neurotransmitter producers and receptors are at the same time up- or down-regulated to optimise communication.

When sufficient signaling has ocurred to make it clear which association pathways are most often used, acetylcholine is released to shut down those association pathways with no-use or low-use density, which leaves the network with fine tuned probabilities for association.[30]

This process requires no conscious thought, in fact even organisms as simple as a slime mold can demonstrate the automatic problem-solving power inherent in networks. There are several videos of the process online and in one you can watch the mold solving a maze in the lab; the mold was more efficient at the task than graduate students. Researchers are planning on creating a bio-computer using slime molds, because its information-processing system would be quite close to that of the human brain. [34]

Categorizing memories and filing them where they belong by association for the long term is called Long Term Potentiation (LTP) or memory consolidation. Most of this transfer to long term storage takes place in our sleep, and it performs the equivalent task to defragmenting your hard drive -all data that should be associated together are moved out of RAM to locations for permanent storage together with previous similar data, aiding coherence of association, fast reformatting for local processing, and speed of recall.

Core associations divide N3’s inner model into categorization ‘territories’, each catering for one main network and its type of processing and memory, and because the inner model represents association by area, so the area coordinates of neuronal firing on the inner model during recall of a long term memory automatically reveals what sort of memory it is.

We literally embody the mind, and all memories are both physical links between cells and mental associations between concepts. The architecture of our brain inevitably forms an analogically- representational model of its contents.

 

Variation: retrieval

Individual basic concept memories are all made in the same way. In recall, the trick for making detailed accurate memories out of them lies in the ability to recombine them into accurate copies of previous patterns of neuronal firing and coincident association.

Remember, each network only holds its own parts of each memory –the part that relates to its own core category. Everything in a category and between categories is related through association. It is the patterns made when the trigger of one part summons a replay of all parts in unison that make us “remember” as a whole experience.

When a memory is ‘recalled’ (commonly known as 'retrieval'), it has to be imagined (portrayed in an image based format), reassembled from all memory ‘departments’ as an integrated whole, association being automatic, and this ‘assembling’ takes place largely in network 3. The image is a trigger for 'weighting' transmitter release as well as associated recall. The neurotransmitters released form a similar chemical state to that of the original memory, evoking similar emotions. The more accurately weighted the memory, the more accurately the mental state from the original memory is reproduced.

We don't notice that memories are a conglomerate of aspects of memory because they are presented to us; the user, as a 'fait accompli'. When we remember how to ride a bike, for example, we don't realize that this involves remembering what a bike IS, what we are, what roads are, what are the concrete physical body-mechanics of bike-riding, how to maintain balance during various motions, what street signs mean, what is the route we wish to follow, and so on. Add to this what bike riding feels like, sounds like and smells like, and we are approaching a whole memory, but there's still a lot missing...what other aspects of this memory were furnished by the original context?

Since the pattern of encoded responses in the original input is what makes us imagine (perceive) and remember what went on in the first place, so the resulting memory is bound to be ‘reproduced’ if the cells are signaled to run the same sequence of movements again. Similar events cause similar patterns, whether they are coming in, going out, being observed, or just being considered.

Hopefully it is plain that when we recall or remember something, what we are doing is re-imagining it. Some things that we can “see” in our imagination are things that have really happened, and we imagine them happening when we remember them. Memory is ‘projected’ onto the ‘screen’ of the mind’s eye by imagination.

For recall, any signal causing the same sequence of physical cellular movements automatically calls up the same abstract concept associations. –They are literally ‘re-called’; they are summoned back from disparate areas to merge into a coherent whole in our mind; an entire episode. THIS is 'episodic memory'; a merging of sensorimotor and spatial and other aspects of memories, with N3 & N6 running the show.

Remembering is simply imagining the past, just as perception is imagining the present and prediction is imagining the future.

We imagine the patterns of the past and we call it ‘memory’. We imagine the possible patterns of the future and we call it ‘prediction’. We imagine the patterns of the here and now, and we call it ‘perception’.

This same process (in the same networks) is used for perception of the here and now, remembering the past, prediction about the future, and also for establishing empathy and a theory of mind. In other words imagination itself prompts the storing of images, the recall of images, and the assembling of the ‘inner picture’ we call perception. The process of imagination uses memory as a database, and is responsible for its content.

 

Coordination: reconsolidation

The conglomerate that is a memory is not constant. Every time a memory is recalled it is updated. Instead of remembering it exactly the way it was, we incorporate any new associated information relevant to it and update the memory according to the new information.

Sometimes we change our associations with it so much that we recategorize it (remember anything you hated the taste of as a kid that you now like?)

Mainstream beliefs about consolidation have been re-evaluated as a result of studies showing that prevention at reconsolidation with protein synthesis inhibitors and many other compounds affects subsequent retrieval of the memory and can even lead to an amnestic state.[32] Memories are updated during reconsolidation; not during retrieval.[54]

Reconsolidation is an important process for neurohackers because it is the easiest point to hack wrongly-weighted memories. This is also important to remember in co counseling.

We'll discuss methods for hacking wrongly weighted memories in future tutorials.



DO IT NOW


comparing memory & imagination

Remember swimming, riding a bike or a horse, or playing a sport.

Notice how you automatically place the memory in a context by association.

This works with imagination as well as memory -remember when you imagined the tiger?

Watch the same system at work in the following exercises:

Remember the last animal you saw. Now imagine an animal you've never seen.

Remember a trip you once took to a place you liked. Think of a place you would like to visit and imagine what it might be like. Imagine taking a trip through time to the same place you are now, 200 years ago. What do you imagine it would be like? What about 200 years in the future?

 

 

Perception and Memory – A Summary

 

To make a long term memory of an event, experience or information, we go through the following procedure as demonstrated by our lab rat “Bob”:

Receiving: Input enters via our senses and networks 1-3 as a stream of information about temperature, light, pressure, sound, smell, movement etc. Your senses take in what something looks like, smells like etc, from the incoming patterns of light frequencies and shapes of chemical smell molecules.

 

Perceiving: We compare this pattern of input to the patterns we already have in our memory. From similarities and differences to previous patterns of experience (known concepts) we construct a new pattern that forms an ‘inner picture’ of what is going on “out there”. This happens in all sensory perception, whether we are going to remember an experience or not. We begin to ‘re-cognise’ –make an inner picture of what the item is. (e.g., looks like a fruit, smells like a fruit).

Patterns of thought and activity obviously occur all over the brain. Different networks process different kinds of information - sounds, sights, tastes, smells, etc., but all networks send their bursts of activity to –and get feedback from- the hippo & amy. The hippo & amy in N3 create and assign a pattern with a chemical weighting tag, keep a copy in RAM, and send that coded signal plus tag on to the relevant networks.

Encoding: The brain needs to distinguish between significant experiences and those that carry less importance, giving priority to the transformation of the former into long term memory. Critical in this process is the emotional load or ‘weighting’ of an event.

Studies have shown that heightened states of emotion facilitate learning and memory.

Neurotransmitters are known to play a central role in the emotional weighting of memory through their effect on receptors in the brain, and are also involved in inducing Long Term Potentiation (LTP) –the making of new long term memories. LTP involves a lasting increase in the strength/density of nerve connections, at synapses. This process is now considered to be the cellular basis for learning and memory.]

 

 

Patterns that cause emotional arousal prompt the release of neurotransmitters and what these are will depend partly on your personal experience. For example, if Labrat Bob got sick after eating a similar piece of fruit, serotonin will prompt a memory of disgust, which will attach to the current ‘fruit’ image.

Our mammal has remembered a similar fruit, and has attached serotonin and cortisol as the chemical packet associated with the experience. He is now feeling disgust, the chemical packet attached to the memory he just recalled, which associates 'fruits like this' with tummy ache.

If you normally like 'fruits like this' and you are hungry, dopamine will be attached and you will desire to eat it.

Emotional arousal such as is caused in play, for example excitement, curiosity, exploration, eagerness to learn, provides the neurotransmitters (dopamine, norepinephrine) for the ‘stretch’ part of making memories or the learning cycle. For the ‘relaxation’ part (acetylcholine, serotonin), if we’re healthy, all we need to do is go to sleep. In all parts of learning the brain is doing most of the work unconsciously, and in the consolidation stage our awareness is restricted to the brief snatches of eidetic imagery that reach as far as our consciousness in dreams. (The mind trying to make sense out of this imagery is what we call ‘a dream’.)

The ‘inner picture’ plus the chemical ‘attachment’ of the memory provide an appropriate behavioral response based on the evidence the system is aware of so far.

Working memory only attends to what is going on right now. If you are asked to remember a phone number until you can find a pen, your brain puts it on the clipboard. All is well unless you are then handed a cup of coffee, your computer crashes and then the doorbell rings. After putting your drink somewhere sensible, answering the door and explaining to some sales guy that you don’t want to buy anything, and sorting out the computer, the phone number is almost certainly no longer on the clipboard! This is not because you have a bad memory but because there simply wasn’t room. With practice you can increase the size of your clipboard, but it has limits. So things that are important need to come off the clipboard and into RAM for short term storage, and if they are important enough, to go on into permanent long term storage (consolidation).

 

 

Consolidation: If something is important enough to remember, the chemical ‘packet’ causes a cascade of transmitters to be released that signal the genome to make some new proteins. These proteins are used to build stronger connections between all the networks that took part in the experience. This is the meaning of the golden rule “Cells that fire together, wire together”, because they do so literally; this is how plasticity works. While this new construction work is going on, we store the memory in network 3 like RAM, just like a computer game does if the information is recent and you might need it again soon. If a series of related experiences is ongoing, we hold essential immediate information on the ‘clipboard’ (in network 6) as ‘working memory’.

Whenever we go to sleep, or spend time blankly staring, or in meditation, new memories are defragged and moved from RAM into their permanent locations around the entire brain. If you view the different networks as different ‘core processors with dedicated hard drives’ in a computer you’ll get a pretty accurate picture of how long term memory is selected and stored. There are some bits of every memory on every drive –but N3 does most of the code processing, and it does it all through association with core concepts.

Technical ingenuity has now provided neuroscientists with the ability to view defragging in real time; scanning a sleeping rat has revealed that the record of its journeys through a maze during the day was encoded by place cells in the hippo and played back during its sleep –as a result of which it remembers the maze in the morning. The brain does a lot of its work when you’re sleeping –and this is why sleep is so important for intelligence.

You don’t have to ‘observe’ during defragging; you don’t need conscious awareness; indeed it would get in the way (which is why you’re asleep). Your memory just needs defragging –sorting things out and putting bits of similar things together to free up more space in RAM.

This is why we can go to bed with an unsolved problem bothering us, yet when the cognitive networks see the resulting patterns in the morning, sometimes we ‘suddenly solve the problem’, often thinking, ‘why couldn’t I see it before?’ The reason was, it wasn’t there yet. You really do allow your brain to solve problems while you’re sleeping, simply by allowing it to consolidate more associations into the 'big picture' of what is going on.

The brain does most of this during slow-wave & REM sleep, meditation, and blank staring without thought –which you will sometimes catch it doing on its own whenever we have a quiet moment and are not busy with processing real-time inputs.

So now you know. If you get stuck in these tutorials, just crash out…(wouldn’t it be great if all tutors said this?) But now you may see a further problem with schooling –trying to teach a lot of people the same thing at the same time cannot work when each individual is going to have different optimal times for sleep and wake in order to learn optimally. If people are going to learn together, they have to not only live together but also be at similar enough stages of development, at which point their biological functions become synchronized. In a class of strangers, everybody is dependent on the other guys’ ping rate, and all you boys and girls who play games online will know what THAT means.

 

Retrieval
Each network uses the same graphic template and tag to retrieve its own part of the memory. Graphics are like ‘zipped’ formats that enable the brain to pack a lot of information into a few bits of code. It’s a bit like being able to copy a movie in less time than it takes to watch it –and for precisely the same reasons.

Memory is a process, just as imagination is a process. In this sense, memory can be viewed as a function of imagination. Reminders do not trigger 'a memory' -they trigger a process in which imagination constructs an ephemeral product -the re-formation of an event/experience in inner spacetime. When not being used, that product no longer exists. The 'memory' was a product of a software process and is a transient rather than a permanent phenomenon, much like models built from lego are not stored as models but dismembered and stored as a box of lego bricks. If you want to reproduce a model made in the past, you have to put the bricks together again in the same way you did first time.

This is because each network stores only its own part of each memory, and they have to be brought together (re-membered) in the correct configuration by N3 for every recall. The brain keeps memory parts tidily in their own compartments, like a nice new box of lego, which makes model assembly easier.

Memories are not constant and unchanging because pn recall, current updating information is added to past fragments to update memories.

 

Reconsolidation

On re-storing the memory components, these added components are meshed in with the rest to be recalled the next time that particular configuration is required.

These are the basics of how a memory is made. From previous tutorials we already know a little about the brain’s plasticity and how connections between neurons are physically changed (made denser) when a memory is made or a new thing is learned. This is achieved via the triggering of gene-transcription factors (chemicals that can turn genes on and off), by neurotransmission instructing the gene to make new proteins that are used to build the denser physical connections.

We realize that we have only sketched the surface of how memory works here, and if you feel you’d like more scientific information about memory on a deeper level, look in the files under ‘plasticity’ or google ‘Hebbian plasticity’ and ‘Long Term Potentiation’, as we’re not going into too much scientific detail in these practical tutorials. The proof is out there. [56]

 

 



Last Updated on Monday, 29 May 2017 13:32