How to have a long term memory

Enhancing Long-Term Memory: 7 Strategies For eLearning Professionals

Summary: Memories may serve as fond reminders of the past, but they also allow us to achieve learning goals and expand our educational horizons in the here-and-now. It would be nice if our minds functioned like cameras and we could access our picture-like memories at any time we wanted. Unfortunately, this is not how it works; everything we see and hear is stored in different areas of our brains and we can easily lose information it if we don’t make a conscious effort to retain it. In this article, I’ll explore the basics of long-term memory and I'll share 7 strategies you can use to create memorable eLearning courses, the content of which will be stored in your audience's minds for a long, long time.

The long-term memory of your learners is your final destination when you are designing and developing an eLearning experience. As its name suggests, long-term memory, unlike short-term memory, stores information for a long time; it is debatable whether “long time” means a lifetime, but undoubtedly the relatively permanent memory storage of your audience is where you want your eLearning course to find its place. The long-term memory, in particular, allows your audience to retain and recall the concepts and ideas that they need outside the virtual learning environment. To create an effective, unforgettable eLearning course, it is essential to have an in depth understanding of how the information will be remembered. In this article, I'll delve into the topic of long-term memory and I'll share some useful strategies to help you make sure that your learners retain your eLearning content.

The Long-Term Memory Types

Many cognitive psychologists believe that the long-term memory is divided into two distinct types: explicit memory and implicit memory.

  1. Explicit or Declarative Memory.
    Explicit memory, also known as declarative memory, is made up of memories that we are conscious of remembering and capable of describing in words. Explicit memory can be subdivided into semantic memory, which refers to our memories that are drawn from common knowledge, such as facts and general knowledge about the world, for example  the names of colors, and episodic memory, which refers to memories that are drawn from our personal experiences.
  2. Implicit or Non-Declarative Memory.
    Implicit memory, also known as non-declarative memory, consists of subconscious memories, like knowledge that allows us to carry out basic tasks without even realizing we are recalling the information. For example, when you type on a keyboard you are not conscious of the long-term memories that are allowing you to perform the function. Information that is encoded in implicit memory, such as knowledge concerning our body movements, can be recalled automatically, without us needing to make a conscious effort. Because it flows effortlessly in our actions, it is often difficult to be verbalized, that's why it's also known as “non-declarative”. Implicit memory can also be subdivided in two types: procedural, which refers to recalling how to do things that require action, such as walking or playing the piano, and priming memory, referring to the automatic activation of certain associations of new with previous knowledge. A popular example that describes how priming memory works is that when one reads the word “yellow”, they will recognize the word “banana” slightly faster than the word “sea”.

Cognitive Processes Involved In The Long-Term Memory

Long-term memory is not just a permanent storage that archives information. It also involves other cognitive mechanism such as providing the working memory with relevant background information in order for the latter to acquire meaning. The long-term memory, therefore, performs three basic operations: encoding, storage, and retrieval.

  1. Encoding.
    Encoding is the ability to convert data we collect into a knowledge-based structures known as schemata. New information is either just added to existing schemata enriching them, or contradicts with them and finally manages to alter them. The first process is known as assimilation, though the second as accommodation.
  2. Storage.
    Simply put, storage is the ability of long-term memory to store information in different brain areas. For example, semantic memories, such as facts are stored in different brain areas than automating procedural memories, such as how to ride a bike. We cannot be sure, neither for how long, nor for how much information can be stored in the long-term memory. Theoretically speaking, the long-term memory has unlimited capacity and information there can be stored for the rest of lives. It is also still debatable whether information stored in long-term memory can be permanently deleted, as "deletion” may involve just inability to locate or retrieve information, rather than permanent loss. It has been found that forgetting is basically the result of either poor initial encoding of information or poor retrieval methods.
  3. Retrieval.
    Retrieval, or else, remembering. Retrieval of information is the process of not only activating, but also using information that is stored in long-term memory. There are two distinct forms of retrieval: recall, which refers to generating or reproducing stored information we've already acquired, and recognition, which refers to identifying stored information that is familiar. Needless to say, recognition is much more effective than recall, as meaningful associations don’t require as much depth of processing or cognitive effort.

Enhancing Long-Term Memory: 7 Strategies for eLearning Professionals

Indeed, it is quite challenging to find how to process information in ways that will keep it fresh and accessible. This is where your eLearning skills come in. In order to help your learners retain your eLearning content, consider using the following memorization strategies:

  1. Repeat, repeat, repeat.
    Fascinating brain fact: We have (one hundred billion!) neurons in our brain and each of them is connected to 1000 others. Neurons’ main role is to transfer information by “firing” impulse signals to their neighbors, who transfer the same signals to other "neighbors" of theirs, and so on. It's exactly like a domino effect. The connection between two neurons is called “synapse” and it increasingly gets stronger, the more frequent the signals between two neurons become. Because memories, just like thoughts, are represented by the resulting patterns of neuron firing, the stronger the synapse between two neurons, the more reinforced a trace of memory becomes and the higher the likelihood to be retrieved. This is where you come in; as an eLearning professional, wanting to offer your learners a memorable eLearning course, you need to find a way to strengthen the neural networks in their brains. You don’t need to have a neuroscience degree to do this: Just repeat the information you offer them over and over again. For example, repeat your eLearning objectives and goals throughout the eLearning course, use keywords as often as possible and don’t forget to summarize each section or topic after completion. This way, it will be more likely for the information to end up in the long-term memory of your learners, and they will be able to remember it with greater ease and accuracy later.
  2. Use multiple ways to present the information.
    Repetition allows your learners to soak up the information more rapidly and for longer spans of time, even concepts that may be more difficult to understand. However, it’s important to switch up the formats in which the information is delivered. If you give them the information via a scenario in one lesson, provide it in multimedia format or as a story in the next. Not only will this raise your learners’ interest in the eLearning content, but it will also improve retention. For example, creating an audio narrative of the information followed by a video presentation that emphasizes similar key points will appeal to auditory learners as well as visual learners.
  3. Think of REM (Relevance, Emotion, Meaning).
    REM initials here neither stand for Rapid Eye Movement sleep nor the famous rock band; instead, they refer to 3 essential eLearning course qualities: Relevance, Emotion, Meaning. I'm sure you will definitely remember this tip. Why? Because I've just followed a great memory strategy; I related a new piece of information to an already existing, familiar one. Information can be tranferred from short-term to long-term memory only when it's meaningful. To facilitate information transfer to the long-term memory, create meaningful eLearning courses.
  4. Integrate stories that trigger an emotional connection.
    Follow an emotional approach that will engage your audience, and provide your learners with eLearning content that they feel they can relate to. Learners are more likely to remember information when it’s tied to a personal experience or an emotion. For example, if you include stories in your eLearning course that are relatable for your audience, they will automatically pair the semantic memories (facts) with their episodic memories (personal experiences). This enables them to create an emotional connection with the subject matter and store it away in their long-term memory. Make sure that your stories are actually linked to the learning goals and objectives, or else they simply won’t provide your learners with any real value.
  5. Use scenarios and simulations to access previously learned subject matter.
    Scenarios and simulations take active retrieval a step further by immersing your learners in the subject matter. They are then able to make meaningful connections between what they stored in their long-term memory and real world applications of that information. It’s also important to create exercises that mimic real world challenges or fit into the context of how they will be applying the knowledge outside the virtual classroom. For example, if they must learn how to perform a basic customer service task, develop a scenario that tests the skills and steps that are involved in the activity. This will encourage their brains to link the knowledge to that particular process, which will make it easier for them to recall it in the future.

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  6. Use chunking. Break the eLearning course into bite-sized lessons.
    Distributed practice is the key to knowledge retention. Break your eLearning course into smaller lessons that are easier for your learners to digest, rather than overwhelming them with too much information at once. This gives them the ability to gradually absorb the information and assimilate it into their long-term memory, rather than forgetting key concepts just seconds after they’ve learned them. The chunking method was first introduced by a pioneer in the field of cognitive psychology, George A. Miller, and it refers to taking individual units of information and grouping them together, so that it is easier to store large amounts of data in the short-term memory. Chunking can be particularly helpful to eLearning professionals, as it enables you not only to get rid of useless information, but also to effectively organize and structure your eLearning course. Prioritize your material by choosing primary and secondary points, and divide your eLearning content into sections. Use different screens for each topic and highlight key ideas by using bullets and numbered lists and colors or bolded fonts in order to make them stand out in the minds of your learners. Finally, if you are integrating images and multimedia into your chunking method, keep in mind that they need to be relevant to your audience. This way, they will be provided with a clearly structured, meaningful and memorable eLearning experience.
  7. Prompt your learners for “active retrieval” of previous knowledge.
    When you encourage your learners to retrieve memories from the long-term memory banks, you are tapping into the power of “active retrieval”, which helps to improve knowledge retention and reduces the risk of memory decay, by actively involving your audience in the eLearning activities you provide. It’s a good practice, these eLearning activities and assessments to prompt your learners to make use of previously acquired knowledge in order to be able to answer correctly. Rather than simply reading a summary of what they have learned so far, it is believed that recalling and utilizing information is much more effective than simply reviewing it.

The ultimate goal of any online learning experience is to provide the long-term memory with usable material for the future. It is to stick in the minds of its learners, so that they are able to delve into the depths of their memory to apply what they have learned in the real world.

Now that you know how long-term memory works and how to use the facts for the benefit of your eLearning course, you may be interested in busting some memory myths. Read the article Memory: Types, Facts, and Myths and find the truth behind the 7 most common memory misconceptions.


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Memory - Harvard Health

What is Memory?

As we age, it’s common to worry about losing our memories (That’s partly because a certain amount of age-related memory loss is perfectly normal). In order to preserve your memory as you age, it’s important to understand how memory functions. So, what is memory? Where in the brain are memories stored, and how does the brain retrieve them?

Quite simply, memory is our ability to recall information. Scientists talk about different types of memories based either on their content or on how we use the information. For example, remembering the layout of your grandmother’s kitchen is different in both content and purpose than remembering the middle three digits of a plumber’s phone number while looking at his business card as you dial the phone. The main two categories for memories are short-term and long-term.

Short-term memories involve information that you only need to recall for a few seconds or minutes. If you’re turning at an intersection, the fact that there were no cars coming when you looked to the left is important, but once you’ve made your turn you will quickly discard the information because it is no longer relevant. Keeping it around would unnecessarily clutter your brain.

Long-term memories contain the information that makes you you—not just facts (like the capital of Kansas) or events (like your senior prom) but also skills and processes (like typing or dancing the Macarena). Long-term memory is durable yet changeable; a memory can evolve based on retelling a story or on new information learned after the event.

Memories are not stored in a single location in the brain. Instead, the sensory components of a memory—sight, smell, sound, etc.—are distributed to different areas of the brain, and the act of remembering occurs as the brain pieces those bits back together. Each time a memory is created, its constituent parts are catalogued in the deep-brain structure known as the hippocampus. Next to the hippocampus sits the amygdala, the brain’s emotional center. It flags certain memories as being important or emotionally powerful. The different components of the memory are then distributed mostly to sections of the cerebral cortex, which is the outer layer of the brain.

When it’s time to retrieve a memory, you rely on the part of the brain known as the frontal lobes, which are involved in attention and focus. The pieces of the memory are then pulled from the areas of the cerebral cortex where they’re stored. For example, to remember a scene from your favorite movie might involve pulling in data from the brain’s visual region to recall the backdrop and the actors’ faces, but also information from the language region to remember the dialogue—and perhaps even the auditory region to remember the soundtrack or sound effects. Together, these components form a unique neuronal pattern that lies dormant until you set about remembering it, at which point it is reactivated.

What Causes Memory Loss and Forgetfulness?

Like the rest of our bodies, our brains change with age, meaning that most of us will find ourselves struggling to recall newly learned information or even to think of words we know well. That’s usually not cause for alarm, since some memory loss in elderly people is quite normal and not indicative of memory loss diseases such as Alzheimer’s. But what causes memory loss, and how and why does memory change with age?

Many of the things we think of as normal memory loss with aging can actually be attributed to a slight decline in our ability to perform tasks requiring attention and so-called executive function (planning, sequencing and regulating thought). Specific age-related changes in the brain are associated with that lower executive function. For example, to think of an acquaintance’s name, you must rapidly make connections between brain cells. Each cell (called a neuron) is separated from its neighbors by a tiny gap called a synapse, and a signal from one brain cell must cross that gap to the next one via a chemical messenger called a neurotransmitter. Once across the gap, it must “unlock” a structure called a receptor on the destination cell. With age, both the brain’s chemistry and the structural integrity of the neurons’ wiring deteriorate (The hippocampus, crucial for memory processing, also shrinks). That doesn’t mean you’ll never be able to recall the bit of information that’s eluding you, but it does mean it might take some time for the brain to forge a path to where the memory is stored. Thus most “memory loss” in seniors is actually just a slowing of performance. You can still learn, retain, and recall plenty of information, but it might take you longer—and require a bit more determination—than it did when you were younger.

Some forms of memory loss are caused by head trauma, including brain injuries resulting from high-impact sports such as boxing, soccer and football. Memory loss can be part of a primary brain disease. But it can also happen in people with depression, thyroid malfunction and even vitamin deficiencies, all of which can result in improved memory with appropriate treatment.

We also know that stress, fatigue, sleep deprivation and the feeling of being overwhelmed can contribute to short-term memory loss and forgetfulness. Middle age can be a difficult period of life in which our responsibilities can extend to ourselves, our spouses, our jobs, our children, our parents and even our grandchildren. It’s not uncommon, then, to feel distracted and find it harder to concentrate on things we’re trying to remember.

So how do you know when to visit a doctor for memory loss? If you begin to experience difficulty completing familiar tasks, or have bouts of forgetfulness that extend beyond minor inconvenience and disrupt your day-to-day functioning, there may be something more serious going on than normal age-related memory loss.

What is Mild Cognitive Impairment?

Mild cognitive impairment (MCI) occurs in nearly 20% of adults over age 65. While many people assume it is a precursor to full-blown dementia, fewer than half of people with MCI go on to develop Alzheimer’s dementia within five years. MCI is marked by either memory loss, a decline in cognitive fitness, or both, that is worse than should be expected for the patient’s age.

When the impairment is largely memory-related, doctors refer to it as amnestic MCI. With normal age-related memory loss, people tend to forget fairly trivial things like where they put their car keys. But with amnestic MCI, the things patients forget are more important—who the presidential candidates are, what was discussed in last week’s Zoom meeting, what college your granddaughter attends. Even so, the impairment is considered “mild” because it does not significantly impact day-to-day functions like preparing food, driving and personal hygiene.

The other main subtype of MCI is called non-amnestic. Rather than affecting memory, non-amnestic MCI manifests as cognitive decline in other areas such as language, spatial awareness or the ability to focus and maintain attention. Someone with non-amnestic MCI might find it difficult to keep up with a conversation, pay their bills, make decisions, repair a faucet or understand a speech. Again, however, the impairment is not so severe as to disrupt everyday life.

People whose MCI affects both memory and other types of cognition are said to have multi-domain MCI. Amnestic MCI is the most common subtype.

MCI is highly variable in terms of its severity and trajectory—it may worsen, stay the same or even go away, depending on what’s causing it. Temporary MCI can be brought on by sleep apnea, depression or medications. Risk factors for other kinds of MCI include genetics, stroke, head injury, high cholesterol, high blood pressure, obesity, smoking, and hearing loss. It’s important not to think of these risk factors as “causes” of MCI—instead, each has been associated with the condition.

What is Dementia?

Many people confuse mild cognitive impairment (MCI) with dementia. While MCI can in fact be a precursor to the early stages of dementia, dementia is a separate brain disorder. The symptoms of dementia are so severe as to render the patient dependent on others to carry out the tasks of everyday living. But exactly what is dementia?

Although memory loss is one of the most common signs of dementia, the disorder often entails other forms of cognitive decline, including a drop-off in the ability to think abstractly, to make reasonable judgments, to speak and understand, and to relate spatially to the environment. Perhaps just as alarming, dementia patients often undergo significant changes to their personalities, becoming agitated and sometimes experiencing delusions.

There are several types of dementia.

Most people know or have heard of someone with Alzheimer’s disease, a type of dementia marked by short-term memory loss so severe that patients often ask the same question minutes apart, forgetting that they have already received an answer. Alzheimer’s patients also frequently experience severe personality changes. People with Alzheimer’s disease have excessive amyloid plaque and neurofibrillary tangles in the brain. But whether these changes are the actual cause continues to be explored. That’s because many older people have similar brain changes but never develop dementia.

Vascular dementia is caused by an interruption of the blood flow to the brain. This can happen after a stroke, brain bleed or head trauma, But more often the cause is reduced blood flow from narrowing of multiple small arteries that feed oxygen and nutrients to the brain. The symptoms are similar to people with Alzheimer’s disease, but it also depends on which parts of the brain are most affected.

Dementia with Lewy bodies arises from an accumulation of harmful proteins in the brain cells causing progressive problems with cognition, memory and movement.

Although Parkinson’s disease is usually thought of as a movement disorder, some people develop symptoms similar to other types of dementia, such as problems with executive function, information retrieval and attention.

Frontotemporal dementia occurs when neurons in the brain’s frontal lobe or temporal lobe die off, leaving the patient to experience personality changes so stark as to be frequently misdiagnosed as psychiatric problems.

The symptoms of primary age-related tauopathy, or PART, can appear similar to those of Alzheimer’s disease. But the symptoms of PART are mostly limited to memory loss and not the other cognitive-behavioral problems usually associated with Alzheimer’s.

People with more than one of these memory loss diseases are said to have mixed dementia.

What is the Difference between Dementia and Alzheimer's?

Dementia is the generic term for cognitive and memory decline sufficiently severe that the patient requires assistance with everyday functioning. Alzheimer’s disease is the most common cause of dementia, with nearly 5 million Americans affected, but it is by no means the only cause.

Alzheimer’s is a progressive disease, meaning that it worsens over time, sometimes in as little as four years. During the early stages, the patient experiences memory loss but is still able to live independently. In mid-stage Alzheimer’s, the patient may begin to neglect their personal care and to forget significant information. By the late stages of the illness, people require help with even the most basic aspects of daily living, and normal conversation becomes impossible.

What happens to the brain to cause Alzheimer’s? Two substances play a likely role. Both are naturally occurring proteins. Beta-amyloid accumulates in the brain until it forms plaques in the gaps between nerve cells that are conduits for signals that travel through the brain. The other key protein, called tau, also accumulates over time and forms tangles inside the brain cells. The two proteins together kill cells in areas of the brain necessary for memory, personality and other cognitive abilities.

How to Improve Memory and Concentration?

The good news is that, although with age you should expect to experience some forgetfulness, there is plenty you can do to minimize memory loss and even improve and enhance your memory as you get older.

Among the best ways to improve memory are the same lifestyle changes that reduce the risk of heart disease and stroke. For example, quit smoking, drink alcohol in moderation or avoid drinking completely, and limit intake of sugary and processed foods.

But when it comes to how to improve memory, eliminating factors is just part of the puzzle—the other piece is adding in new habits. For example, eating foods that help memory, such as leafy green vegetables, nuts, berries, tea, coffee and oily fish, is a great way to promote your overall health while strengthening your brain.

Regular exercise boosts the growth of brain cells and the production of neurotransmitters, enhancing memory. A mix of aerobic (cardio) and strength exercises is best.

If you’re not getting enough sleep, you might be harming your cognition and memory. Aim for seven to nine hours each night.

Meditation, stress reduction and keeping up a good network of social relationships have all been shown to stave off the effects of aging on the brain.

One key to keeping your mind young is to keep it busy and challenged through lifelong learning and stimulation. Traveling, learning new languages, picking up a musical instrument, taking art or cooking classes, doing puzzles, playing board games—all these things promote the growth of new brain cells and help the brain forge new pathways.
Memory enhancement can also come from properly managing your physical and mental health.

If you know or suspect that you suffer from depression, get it treated.

Since many medications can cause brain fog and bouts of forgetfulness, you should review your prescriptions with your doctor and see if dosages can be changed or eliminated. Especially consider drugs with anti-cholinergic properties, such as the older antihistamines (e.g. diphenhydramine, Benadryl), some older antidepressants (e.g. amitriptyline, Elavil), and drugs for urinary symptoms (e.g. oxybutynin, Ditropan).  

Checking your hearing, vision, blood pressure and blood levels of thyroid function and cholesterol may find abnormalities which could easily be addressed and result in improved memory.

Brain experts have developed many tips for improving memory as you attempt to remember such things as names, to-do lists, facts or other information. For example, associating new information with things you already know can help you retain it—like remembering that you’re in parking spot 42 because your son is 42 years old. With another technique, called chunking, you break up a list into categories—if you were memorizing all the countries of Europe, grouping the Baltic States (Estonia, Latvia and Lithuania) lets you see them as one group. Using a more advanced technique, called loci, you “visit” a familiar location in your mind, mentally placing the items you want to memorize at various places along the path.

Certain habitual behaviors will help you remember the information that gets you through your day. One such habit is staying organized—if you always put your car keys on the counter, you won’t have to wonder where you left them. If you write down every appointment or put it into your smartphone, you won’t miss any. If you keep to-do lists, up-to-date address books, and lists of passwords, you won’t face the struggle of trying to recall information when it’s urgent. It’s also helpful to create certain mental habits, such as repeating a person’s name as soon as you’re introduced, paraphrasing parts of a conversation to reinforce the message, and becoming a more careful reader (and re-reader) to really drive home the content.

How to Avoid Memory Loss?

In study after study, physical activity has been associated not just with higher cognitive function but with a decreased risk of memory loss over time. The brains of people who exercise regularly shrink less with age than those of sedentary people (especially the hippocampus, a brain structure key to memory), and their white matter stays healthier. Exercising three or more times per week has been associated with a 40-50% lower risk of diagnosis with dementia.

In one study, adults at a high fitness level were 88% less likely than those of medium fitness to develop dementia, and high fitness appeared to delay the onset of dementia by 11 years. To reap the benefits of exercise, you must be consistent, so set aside a dedicated time for exercise and stick with it. Swimming, walking and tennis are great activities. Joining a gym and taking fitness classes works very well for some people, since socialization is known to boost brain health.

Another way to avoid memory loss is to be mindful of what you eat. While some specific foods are associated with brain health, food marketers sometimes exaggerate their benefits. That’s why it’s better to think in terms of broad patterns and styles of eating. One rule of thumb is to build your eating habits around foods that are good for your heart, since the same diet that is heart-healthy is also good for the brain. You may have heard of the Mediterranean diet, which has been shown to promote heart health. It centers on plant-based foods, fish, nuts and olive oil. A variation of the Mediterranean diet, called the MIND diet (Mediterranean diet Intervention for Neurodegenerative Delay) was designed with the explicit goal of optimizing brain health. It’s heavy on leafy green vegetables, nuts, berries, fish and poultry, and avoids red meat, butter, cheese and sweets. In one study, MIND diet adherents were 30-35% less likely to score poorly on cognitive tests.

But what about memory supplements? Can’t you simply take an over-the-counter pill or capsule to get a memory boost? Unfortunately, marketers frequently make unproven claims about the benefits of these products. For example, ginkgo biloba is often touted as a wonder supplement for mental function, but numerous studies have found that it has no effect on memory, attention or risk of dementia. You do need certain vitamins for memory, but studies have not shown that taking more than the recommended daily allowance (RDA) has a beneficial effect. Still, B vitamins and vitamin D might merit special attention, since they’re particularly important for keeping dementia at bay. A blood test can tell you whether you’re vitamin B12-deficient, in which case a supplement is a good idea. You can get plenty of vitamin D through 10-15 minutes of sun exposure daily, but if that’s not possible, a supplement may be called for.

Long-term memory (LT) - Cognitive ability

What is long-term memory?

Long-term memory (LT) is a brain mechanism by which we can encode and store an almost unlimited amount of information over a long period of time . The lifespan of memories in long-term memory can vary from a few seconds to several years.

Long-term memory is essential for us to perform our daily tasks accurately and independently. This type of memory refers to the brain's ability to store facts, knowledge, and skills, and to retrieve those memories later. Long-term memory is a complex complex ability for which a large number of brain regions are responsible. Therefore, it is very sensitive to various brain lesions. Fortunately, with practice and cognitive training, this critical cognitive function can be improved. nine0007

CogniFit's leading brain training program will help activate and strengthen our memory and other important cognitive abilities. The smart games it contains were designed to stimulate certain neural activation patterns. Reactivations of these cognitive patterns can help strengthen the neural connections responsible for memory and create new synapses capable of reorganizing and/or repairing the most weakened or damaged cognitive functions. nine0007

Types of long-term memory

According to the time during which information is stored in the memory system, we can divide memory into sensory, short-term, working and long-term. In turn, long-term memory is divided into such types as:

  • declarative or explicit memory : this is the information stored in our memory that we can reproduce verbally. Responsible for this type of memory are brain regions such as the medial temporal lobe, diencephalon, and neocortex. Declarative or explicit memory is also divided into two subspecies. nine0022
    • Semantic memory : refers to the information we have about the world around us. This information is not related to training. It covers our vocabulary, academic knowledge, what we know about each concept and definition. For example, we know that an apple is an edible fruit that grows on an apple tree and can be of different colors, but most likely we will not remember the moment when we remembered all this information.
    • Episodic memory : includes memories of specific events we experienced, is closely related to learning. For example, memories of what we ate for lunch yesterday, where we left the car, when we first visited a new city for us, who came to the holiday last year, and when we met a certain person.
  • Non-declarative or explicit memory : A type of information stored in our memory that we cannot express verbally. These memories we accumulate through implicit learning (unconsciously). This type of memory is more stable in cerebral lesions, so it is less susceptible to disturbance. Various parts of the brain are responsible for it, including the neocortex, amygdala, cerebellum, and basal ganglia. It is divided into several types. nine0022
    • Procedural memory : action memory, information about muscle movements that we have been able to automate through practice, such as skills and habits. Riding a bike, driving, handling a ball, or using a computer mouse.
    • Priming : this is a prior setting that facilitates the process of remembering. For example, most likely, we will remember the word "bird" much faster if we just talked about sparrows or swallows. nine0022
    • Classical conditioning : refers to the relationship between a conditioned stimulus and a previously received response to an unconditioned stimulus. For example, if a bell rings (conditioned stimulus), after which a stream of air is directed into our eyes (unconditioned stimulus), in the future, when we hear the sound of the bell, we will begin to blink (conditioned response). It has to do with non-declarative memory.

Memory test

We need a good memory to perform our daily tasks accurately and independently. That is why it is so important to test and understand the state of our memory. CogniFit offers a series of tests to assess memory (in particular, such types of memory as phonological working memory, contextual memory, working memory, non-verbal memory, visual working memory, working memory and recognition), based on such classic tests, as Long-term Maintenance Test (CPT, Conner Test), Wechsler Memory Scale (WMS), NEPSY (Korkman, Kirk and Kemp), Variable Attention Test (TOVA), Simulated Memory Impairment Test (TOMM), Tower of London Test (TOL) and Visual Organization Task (VOT). In addition to memory, these tests can also measure response time, processing speed, name memory, visual perception, monitoring, planning, visual scanning, and spatial perception. nine0007

  • WOM-ASM Sequential Test: A series of balls with different numbers will appear on the screen. You need to remember this sequence in order to reproduce it in the future. At first, this sequence will consist of only one number, but gradually the number of numbers will increase - until the user makes a mistake. In the task, it is necessary to reproduce all the shown series of numbers.
  • REST-COM Investigation Test: Several items will be displayed for a short period of time. Then you will need to choose the word corresponding to the presented object as quickly as possible. nine0022
  • COM-NAM Identification Test: objects will be presented to you by means of an image or sound. It is necessary to answer in what format (sound or image) the object appeared the last time, and whether it appeared at all.
  • VISMEM-PLAN Concentration Test: Stimuli will appear randomly on the screen. The stimuli will then light up in a specific order with beeps until the sequence is complete. It is necessary to carefully observe both the images and the sounds. During your play turn, you will need to remember the order in which the stimuli are presented and reproduce the given sequence. nine0022
  • WOM-REST Recognition Test: Three objects will appear on the screen. First, you will need to remember the order in which objects are presented as quickly as possible. Then four series of three objects will be presented, some of which will differ from those previously shown. You need to know the sequence you originally saw.
  • VISMEM Recovery Test: Several images will be displayed on the screen for five to six seconds. During this time, you will need to remember as many of the objects presented in the image as possible. Then the picture will disappear, and the user will be offered several options from which they must choose the correct one. nine0022

Examples of long-term memory

  • Most of the knowledge we acquire while studying is stored in our semantic memory. When we study, remember the geography of our country, study anatomy, chemistry, mathematics or any other subject, we use our long-term memory.
  • If we work in a restaurant and need to remember which dish each customer asked for, we turn to our episodic memory. The same thing happens when we remember regular customers, for example. nine0022
  • When we learn to ride a bike, it takes a lot of effort to ride a few meters to avoid falling. This is because we do not yet know how to move correctly. Conversely, if we have practiced enough, our procedural memory will take over the motor skills that we have been able to automate. As a result, we can normally ride a bike. Something similar happens when we learn to drive a car.
  • We use long-term memory to remember where we left our car, our phone charger, which city is the capital of our country, or any other information that we need to remember every day. nine0022

Pathologies and disorders associated with impaired long-term memory

Forgetfulness in itself is not a memory problem. Memory is able to get rid of unnecessary and unused information, especially with age, and this is completely normal. However, there is also pathological forgetfulness, which is an inability to remember new events (anterograde amnesia) and/or an inability to remember the past (retrograde amnesia). On the other hand, there is hypermnesia, a painful exacerbation of memory, characterized by the ability to recall in detail what has been lived in memory, as, for example, in post-traumatic stress. It is also important to note that the content of memories can be disturbed in some disorders, such as Korsakoff Syndrome, in which a person involuntarily invents fictional events from their past. nine0007

Generally, memory is impaired in Alzheimer's disease (mostly episodic), but memory problems can also occur in various dementias, particularly semantic dementia (impaired semantic memory) or Parkinson's disease (impaired procedural memory). These diseases are characterized by a combination of anterograde and retrograde amnesia. In the case of traumatic brain damage, as well as as a result of brain damage during a stroke, anterograde amnesia also often occurs (it is more common than retrograde). In addition, these diseases are characterized by the replacement of memory lapses with fictitious information. Certain drugs and substances can also cause temporary or permanent memory loss. nine0007

Long-term memory is formed simultaneously with short-term memory

Long-term memory and short-term memory are formed in the brain at the same time, but long-term memory cells take time to learn what they have memorized.

We remember everything in two stages: first, the information is in short-term memory, and then, after some time, it is sent to long-term storage. Moreover, the differences between these two types of memory are not only functional, but also structural - they are located in different parts of the brain. nine0007

Cortical engram neurons (in red) responsible for long-term unpleasant memories in mice. (Photo: Takashi Kitamura / MIT.)

Section through the mouse hippocampus showing different neurons stained with different fluorescent proteins. (Photo by Dr. Thomas Deerinck / Visuals Unlimited / Corbis.)

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As you know, several zones are responsible for memory in the brain, and the most important here are the cerebral cortex and the subcortical hippocampus. In the early 50s of the last century, a patient with epilepsy came to neuroscientists, whose hippocampus had to be damaged during brain surgery, after which the patient stopped remembering what had just happened to him, but retained the memory of a more distant past. In other words, if we talk about episodic memory (that is, memory for events), then its short-term version is stored in the hippocampus, and the long-term version is stored in the cortex, which is generally involved in higher cognitive functions. nine0007

But how exactly does information flow from short-term storage to long-term storage—or, to use the usual neurobiological term, how does memory consolidate? According to one model, short-term memory is formed and stored in the hippocampus, only to disappear from it completely. According to another model, which arose much later, in the hippocampus there are still some traces of the information that went into long-term memory.

Suzumi Tonegawa ( Susumu Tonegawa ) and his colleagues at the Massachusetts Institute of Technology managed to largely decipher the mechanism of memory consolidation. Tonegawa needs no special introduction: we have repeatedly written about the work of this outstanding modern immunologist and neurobiologist, Nobel Prize winner, who has already managed to do an extraordinary amount for our understanding of the neurobiological mechanisms of memory. So, one of the biggest achievements of the Tonegawa laboratory is the experimental discovery of the so-called engram cells in the hippocampus. An engram is understood as a trace left by a stimulus; if we talk about neurons, then a repeated signal - a sound, a smell, a certain environment, etc. - should provoke some physical and biochemical changes in them. If the stimulus is then repeated, then the “trace” is activated, and the cells in which it is present will recall the entire memory from memory. In other words, our engram ("key") neurons are responsible for accessing the recorded information, and in order for them to work themselves, they must be affected by a key signal; Obviously, such cells themselves must be able to somehow store information about certain stimuli. nine0007

It is engram cells, as the researchers write in their new article in Science , that are involved in memory transformations. In the experiment, some brain neurons in mice received a genetic modification: a light-sensitive protein gene was inserted into their DNA, so that later such a neuron could be activated by a light pulse (light was supplied to the brain through an optical fiber; in general, all this is called optogenetics, which we have already somehow told in detail).

Neurons were modified in three areas of the brain: in the prefrontal cortex, in the hippocampus, and in the emotional center - the amygdala, or amygdala. A light "switch" was not placed in all cages, but only in those that, in mice, reacted to unpleasant, frightening circumstances: the animals were put in a cage, on the floor of which a weak electric discharge was launched. The mouse was frightened, froze in place, and in its brain, quite specific neurons that fire in response to stress turned on. The mouse remembered a bad cage, and when it was put into it again, according to old memory, it was also frightened and froze, even if there was no longer an electric current. nine0007

Naturally, when memories were found on a mouse, the corresponding memory cells turned on in her brain. These were the same engram cells that stored traces of past unpleasant sensations associated with a particular environment, and responded to a sensory stimulus - the appearance of the cell. There were electrical shock engram cells in both the cortex and the hippocampus, and, what was especially remarkable, they appeared immediately in both places (by “appeared” we don’t mean that new neurons appeared in the brain, but that some of the existing neurons have taken over the function of remembering a particular stimulus). nine0007

However, for example, if a mouse was placed in an unpleasant cage the day after a training electroshock session, then the cortical engram cells were silent, and only the hippocampal engrams were triggered. However, the cortical neurons could be “woken up”: if they were turned on with a light pulse, then the mouse behaved as if something had frightened it - in the same way it behaved when the hippocampal cells were turned on, only these worked. and so, just from the external situation. nine0007

Two weeks later, the picture changed: the engramic electroshock cells in the cortex matured, began to look different and work differently - now they were activated naturally when the animal fell into that same stress cell. On the contrary, the hippocampus cells ceased to turn on - however, some traces of what had happened in them remained, and if they were affected by a light impulse, the mouse fell into fear.

However, for the neurons in the cortex to mature properly, they had to communicate with "colleagues" in the hippocampus who remembered the same things they did; if the connection between the two was interrupted, the long-term memory cells turned out to be "immature", which, obviously, should affect the memory itself. As for the amygdala, its cells held precisely the emotional component of the event, and no changes occurred with them - they worked both with hippocampal neurons and cortical neurons. nine0007

Thus, it cannot be said that information flows from short-term memory, where it was originally formed, to long-term memory, where it was not there at all: in both “departments” it is formed simultaneously, it’s just that in long-term storage, memory remains “raw” for some time, inactive, and needs help from the short-term department to activate it.

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