That cannot be a long-term memory. Long term memory. What influences the efficiency of memorization

22.06.2019

Long-term memory is needed when information needs to be retained either for just a few minutes (for example, a remark in a conversation made earlier) or for a lifetime (for example, an adult's memories of childhood). In long-term memory experiments, psychologists have generally studied forgetting after a few minutes, hours, or weeks, but there have been very few studies involving periods of years, let alone decades. Experiments spanning many years often involve replaying personal experiences (what is called autobiographical memory) rather than laboratory material. In the following, we will not distinguish between studies using one or another material, since they reflected in many respects the same principles.
In discussing long-term memory, we will again distinguish between the three stages of memory—encoding, storage, and retrieval—but this time we introduce two complications. First, in contrast to the situation with short-term memory, there are important interactions between encoding and retrieval in long-term memory. With these interactions in mind, we will touch on some aspects of playback when considering encoding, and look specifically at the interaction between encoding and playback. The second difficulty is that it is often difficult to ascertain whether long-term memory forgetting is due to storage loss or recall failure. To deal with this issue, we will defer the discussion of storage until we consider replay so that we have a clearer idea of what is a reliable criterion for storage loss.
Coding
Value encoding. The predominant representation of verbal material in long-term memory is neither auditory nor visual; it is based on element values. Elements are encoded by their meanings even when they are single words and, more surprisingly, when they are sentences. A few minutes after you hear a sentence, most of what you can reproduce or recognize is its meaning. Suppose you hear the sentence "The author has sent a long letter to the committee." The data show that after only two minutes, you can at best only accidentally be able to determine whether you heard this particular sentence or a sentence with the same meaning "A long letter was sent to the committee by the author" (Sachs, 1967).
Meaning encoding is common in everyday life. When people talk about complex social or political situations, they may misremember many details (who said what to whom, when something was said, and who else was there), but describe the essence of what happened quite accurately. Thus, during the Watergate scandal of the early 70s, the main government witness (John Dean) was subsequently shown to have made many mistakes in describing what was said in certain situations, and yet his testimony is generally considered an accurate description of the events that took place. (Neisser, 1982).
While meaning is the dominant way of representing material in long-term memory, other aspects of it are sometimes encoded as well. For example, we can memorize poems and recite them word for word. In such cases, not only the meaning of the poem is encoded, but also the exact words. The auditory code can also be used in long-term memory. When the phone rings and the other end says "hello", you will often recognize the voice. In cases like this, you had to encode the sound of that person's voice into your long-term memory. Visual impressions, tastes and smells are also encoded in long-term memory. Thus, for verbal information in long-term memory there is a preferred code (namely, meaning), but other codes are also used.
Adding semantic links. It often happens that the elements themselves that need to be remembered make sense, but not the connections between them. In such cases, memory can be improved by creating real or artificial connections between these elements. For example, students of musical notation should remember that five lines in musical notation are designated as EGBDF; although the symbols themselves are meaningful (they stand for notes on the keyboard), their order appears to be arbitrary. Many students therefore turn these symbols into the sentence "Every Good Boy Does Fine" ("every good boy does fine"); each symbol here is denoted by the first letter of the word, and the relations between words in this sentence replace the semantic links between the symbols. These associations aid memory because they provide pathways between words: for example, after the word “good” is played, the path to the word “boy” is opened, the next word to be played.
One of the best ways to add links is to go deeper into the material as you code it. The more carefully the encoded meaning is worked out, the better the memorization will be (Craik & Tulving, 1975). If you need to memorize something from a textbook, it is better to focus on its meaning, and not on the exact words. And the deeper and deeper you expand its meaning, the better you will reproduce it.
The following experiment illustrates some of these points (Brandshaw & Anderson, 1982). The subjects read about facts from the lives of famous people that they later had to remember, for example: “At a critical moment in his life, Mozart moved from Munich to Paris.” Some facts were worked out in relation to their causes and effects, for example: "Mozart wanted to leave Munich in order to avoid entanglement in matters of the heart." Other facts were presented only on their own. Later, the subjects' memorization of only the facts themselves (not their comprehension) was tested. Those facts that were presented in detail, the subjects remembered better than the facts that were presented only by themselves. Apparently, by adding a cause (or effect) to the fact representation in memory, the subjects set the reproduction path from the cause to the desired fact as follows:

During recall, the subjects were able to reproduce the sought-for fact both directly and indirectly, following the path from its cause. Even if they completely forgot the fact they were looking for, they could deduce it logically if they reproduced the cause.
Results like the above point to a close relationship between comprehension and memory. The better we understand this or that material, the more connections we see between its parts. These connections can serve as links in the chain of reproduction, so the more we understand, the more we remember.
Playback
Forgetting in long-term memory is often due to loss of access to information rather than loss of the information itself. That is, poor memory is often attributed to inability to recall rather than poor retention (note that this is different from short-term memory, where forgetting is the result of extinction or repression and recall is believed to be relatively infallible). Trying to recall an item from long-term memory is like looking for a book in a large library. Not being able to find a book doesn't necessarily mean it's not there; perhaps you are looking in the wrong place, or it was simply incorrectly registered.

Data about unsuccessful playbacks. A lot of evidence of failure in reproduction of the material is in everyday experience. Every person from time to time is unable to reproduce the fact or experience, which only then comes to his mind. How many times during the exam you could not remember any name and remembered it only after the exam. Another example is the “on the tip of the tongue” situation, when a particular word or name is somewhere very close, but we cannot reproduce it (Brown & McNeil, 1966). We can get completely bored by rummaging through memory (retrieving and immediately discarding words that are close but inappropriate) until we finally find the right word.
An even more surprising example of failed recall is when, during a psychotherapy session, a person accidentally recalls something previously forgotten. Although we do not have reliable evidence of such cases, they at least suggest that some seemingly forgotten memories are not lost. They are simply difficult to obtain and require a suitable recall feature, which can be anything that helps recall a memory.
For stronger evidence that bad recall can be the cause of forgetting, consider the following experiment. Subjects are asked to memorize a long list of words. Some of them are the names of animals, such as dog, cat, horse; some are the names of fruits, such as apple, orange, pear; some are pieces of furniture, etc. (Table 8.1). During playback, the subjects are divided into two groups. One group is given signs of reproduction - "animal", "fruit", etc.; the other, the control group, they are not given. The group that received the signs produced more words than the control group. On subsequent testing, when the signs of recall are given to both groups, they recall the same number of words. Therefore, the initial difference between the two groups is due to poor reproduction.
Table 8.1. Example from a study of failed replays
Memorable List Dog Cotton Oil Cat Wool Petrol Horse Silk Coal Cow Synthetic Wood Apple Blue Doctor Orange Red Lawyer Pear Green Teacher Banana Yellow Dentist Chair Knife Football Table Spoon Baseball Bed Fork Basketball Sofa Saucepan Tennis Knife Hammer Shirt Shotgun Saw Socks Rifle Nails Pants Bomb Screwdriver Shoes Reproduction cues animals clothing fuel fruits colors occupations furniture utensils sports weapons instrument clothing Subjects who were not given cues recalled fewer words from the memorized list than those who received cues. These data indicate that the stage of recall from long-term memory is responsible for some memory failures (after Tulving & Pearlstone, 1966).
Therefore, the better the signs of reproduction, the better the memory. This explains why recognition test results are usually better than reproduction test results. The recognition test asks if we have seen this or that element before (for example: “Was Bessie Smith among those you met at the wedding?”). The test element in itself serves as an excellent reproduction feature for memories of that element. In contrast, a recall test would call up a remembered item with a minimum of recall features (for example: "Remember the name of a woman you met at a party"). Since the features of reproduction are generally more useful in a recognition test than in a reproduction test, the results of recognition tests are generally better than those of a reproduction test (Tulving, 1974).
Interference. Interference is the most important factor among those that can disrupt playback. If different elements are associated with the same feature and we try to use it to reproduce one of them (the target element), then other elements can also be activated and interfere with the reproduction of the target element. For example, if your friend Dan has moved and you finally learn his new phone number, it will be difficult for you to reproduce the old number. Why? You use the feature "Dan's phone number" to play the old number, but instead the feature activates the new number, which prevents the old one from playing. Or let's imagine that you have changed the place reserved in the parking garage, which you have been using for a year. At first, it is difficult for you to recall the location of the new parking lot from memory. Why? You are trying to learn the association of a new place with the feature "my parking space", but this feature reproduces the old place, which interferes with learning the new one. In both examples, the ability of playback features ("Dan's phone number" and "my parking spot") to activate certain target elements decreases as the number of other elements associated with those features increases. The more elements associated with a feature, the more the latter becomes overloaded and the less efficient the element is to reproduce.
Interference can operate at different levels. In one experiment, subjects first learned to associate various facts with job titles. For instance:
Banker:
1) asked to address the crowd,
2) broke the bottle,
3) did not postpone the trip.
Lawyer:
1) saw that the seam had parted,
2) painted the old barn.
The names of the professions "banker" and "lawyer" served here as signs of reproduction. Since "banker" was associated with three facts and "lawyer" with only two, the word "banker" must have been a less good predictor of reproduction for any of its associated facts than "lawyer", since "banker" was a more overloaded trait. . When subjects were later tested for recognition, they took longer to recognize any of the three facts about a banker than they did to recognize facts about a lawyer. In this study, therefore, the interference slowed down playback. Many other experiments have shown that interference can lead to complete inability to reproduce the material if the target elements are weak or the interference is strong (Anderson, 1983). Indeed, it has long been believed that interference in long-term memory is the main cause of the increase in forgetting over time; in other words, more is forgotten because, over time, the corresponding replay features become more and more overloaded (Figure 8.7).

Rice. 8.7. Dependence of forgetting on time. The forgetting vs. time curve shows the decline in playback. This forgetting curve, the first ever published, comes from an 1885 paper by Ebbinghaus. He memorized lists of 13 syllables, which he repeated until he was able to reproduce the list without errors on two consecutive attempts. Then, after a period of 20 minutes to 31 days, he checked himself, determining how long it took to relearn this list from the original level; the smaller the forgetting, the fewer attempts were required to relearn the list. The figure shows a measure of the ease of relearning (percentage of "items retained") as a function of time; it follows from the figure that we forget a lot of information in the first few hours, but after that the rate of forgetting decreases. This curve reflects the retention of incoherent verbal material, and other curves have been obtained for other types of material (see, for example: Bahrick & Phelphs, 1987). In all cases, interference is believed to play a role in changing forgetting over time.
playback models. A number of reproduction models have been developed to explain the effect of interference. As with short-term memory, some long-term memory recall models are based on a retrieval process and some are based on an activation process.
The effect of interference found in the banker-lawyer experiment is consistent with the notion that long-term memory retrieval is a retrieval process (see, eg, Raaijmakers & Shiffrin, 1981). To illustrate, consider how the sentence from the previous experiment can be recognized: “the banker broke the bottle” (Fig. 8-8). The term "banker" achieves its representation in memory, thereby localizing the search in the appropriate part of long-term memory. From this point on, to be sure that the statement "broke the bottle" was one of the facts about the banker, the search must be conducted in three ways. In contrast, when testing the sentence "the lawyer painted the old barn," there are only two search paths. Since the duration of the search increases with the number of paths to be checked, the reproduction will be slower in the case of the "banker" sentence than in the case of the "lawyer" sentence. In general, reproduction is more difficult when more facts are associated with the reproduction feature, since each fact adds another search path.
Reproduction can also be thought of as an activation process. For example, when trying to recognize the sentence "the banker broke the bottle," the subject activates the representation "banker," and then the activation spreads along three pathways emanating from the representation "banker" (Fig. 8.8). When a certain degree of activation reaches the sentence "broke the bottle", it can be recognized. The interference arises from the fact that the activation coming from the term "banker" must be divided into three paths. This means that the more facts associated with the term "banker", the weaker the activation along each of the paths will be, and the longer it will take until a sufficient amount of activation reaches any particular fact. So thinking of playback in terms of activation can also explain why interference slows down playback (Anderson, 1983).

Rice. 8.8. Reproduction as a search process or an activation process. When presented with the sentence "the banker broke the bottle," the term "banker" achieves its representation in long-term memory; after it has reached its representation, there are three ways to search. When presenting the sentence “the lawyer painted the old barn”, the term “lawyer” reaches its representation, from which two search paths proceed. Or the term "banker" can activate the representation of the term "banker" where this activation is distributed in three ways at the same time (similarly occurs in the case of "lawyer").
Storage
It is unlikely that bad reproduction is the only reason for forgetting. Just because forgetting sometimes happens because of bad recall doesn't mean it always happens because of it. And it is absolutely incredible that everything we have ever learned would still be there in memory, waiting for the right sign to be reproduced. Some information is almost certainly lost from storage (Loftus & Loftus, 1980).
Some evidence of storage loss has been found in people undergoing electroconvulsive therapy to treat severe depression (moderate electric current through the brain causes a brief epileptic-like seizure and brief loss of consciousness; see Chapter 16). In such cases, the patient loses some memory of events in the months immediately preceding the shock, but not of earlier events (Squire & Fox, 1980). It is unlikely that these memory losses were the result of poor recall, since if shock were to disrupt recall, it would affect all memories, not just recent ones. Rather, the shock interrupts the storage processes that consolidate recent memories (of events a month or more old), and information that has not been consolidated is lost from storage.
Most of the research on long-term memory storage is done at the biological level. Significant progress has been made in identifying the neuroanatomical basis of the consolidation process. The main brain structures involved in it are the hippocampus (we discussed it at the beginning of this chapter) and the surrounding cortex (it includes the entorhinal, perirhinal, and parahippocampal cortex; they are involved in the exchange of information between the hippocampus and many other areas of the cerebral cortex). The role of the hippocampus in consolidation is that a cross-reference system is implemented through it, linking different aspects of a particular memory that are stored in different parts of the brain (Squire, 1992). While total memory loss in humans usually only occurs when both the hippocampus and the surrounding cortex are damaged, damage to the hippocampus alone can lead to severe memory impairment. This was demonstrated in a study that began with an analysis of one patient's memory difficulties (due to complications from coronary artery bypass surgery) and ended with a detailed autopsy of his brain after his death; the only damaged brain structure was the hippocampus (Zola-Morgan, Squire & Amaral, 1989).
The best evidence that the function of the hippocampus is to consolidate relatively new memories comes from a study with monkeys. A group of experimental monkeys were taught to distinguish between 100 pairs of objects. In each pair, under one object was food, which the monkey received only if he took it. Since each item was different, the monkeys essentially learned 100 different tasks. Of these tasks, 20 had been learned 16 weeks before the researchers removed the hippocampus from the monkeys; the remaining sets of 20 tasks were learned 12, 8, 4, and 2 weeks prior to the removal of the hippocampus. Two weeks after the operation, the researchers tested the monkeys' memory, giving one sample for each of 100 tasks. The decisive result was that the experimental monkeys remembered differentiations learned 8, 12, and 16 weeks before surgery as well as normal control monkeys, but they remembered differentiations learned 2 and 4 weeks before surgery worse than controls. In addition, the experimental monkeys actually remembered less about the differentiations learned 2 and 4 weeks before the operation than those learned earlier. These results suggest that memories need to be processed in the hippocampus for several weeks, since only memories over this period are disturbed when the hippocampus is removed. Permanent long-term storage of memory is almost certainly located in the cortex, especially in areas of the cortex where sensory information is interpreted (Squire, 1992; Zola-Morgan & Squire, 1990).
Encoding and playback interactions
Describing the encoding stage, we noted that the operations performed during encoding (for example, comprehension) facilitate subsequent reproduction. Other encoding factors also increase the likelihood of successful reproduction: a) organizing the information at the time of encoding, and b) providing a similarity between the context in which the information is encoded and the context of its future reproduction.
Organization. The better the encoded material is organized, the easier it is to reproduce. Imagine that you were at a conference where you met various people of various professions - doctors, lawyers and journalists. When you later try to remember their names, you will do better if you organize the information by profession first. Then you can ask yourself, “What were the names of the doctors I met? What were the names of the lawyers? etc. A list of names or words is much easier to reproduce if we code the information into categories and then reproduce it categorically (see, for example: Bower et al., 1969).
Context. A given fact or episode is easier to reproduce if you are in the same context in which you encoded it (Estes, 1972). For example, if you walk through the corridors of your elementary school, you will most likely improve your ability to recall the names of classmates from first and second grade. Similarly, the ability to reenact an emotional scene with your close friend—say, an argument with her in a restaurant—will increase if you return to the location where the incident took place. This may explain why we are sometimes flooded with memories when we visit a place where we once lived. The context in which an event was encoded is in itself one of the most powerful features of replay, and this is supported by many experimental data (see Figure 8.9 for a typical study).

Rice. 8.9 The influence of the surrounding context on reproduction. To show how context affects recall, one group of divers memorized a list of words while on shore (a) and another group while 15 feet underwater (c). Later, each group was divided in half and asked one half to reproduce the words in the same environment where they learned them (a" and c"), and the other half in a different environment (b and d). Reproduction was generally unaffected by whether divers originally learned the words on land or underwater. But divers who were tested in an environment different from where they learned the words reproduced 40% less than those who were taught and reproduced in the same environment (Godden & Baddeley, 1975).
The context is not necessarily outside the memory, that is, it is not always a matter of environment. What happens inside us while encoding information, our internal state, is also part of the context. For example, if we experience an event while under the influence of a certain drug (say, alcohol or marijuana), then we can best reenact it when we are again under the influence of that drug. In such cases, the memory will depend in part on the internal functional state during learning; this is called function dependent learning because memory depends in part on the prevailing internal state at the time of learning. It is believed that the feelings caused by an altered state of consciousness are the key features of the reproduction of information encoded in this state. Evidence for such learning is conflicting, but suggests that memory does improve when the internal state at recall matches the internal state at encoding time (Eich, 1980).
Emotional Factors of Forgetting
So far we have treated memory as if it were divorced from emotions. But don't we sometimes remember (or forget) material because of its emotional content? This issue has been studied in detail. The results show that emotions can affect long-term memory in at least five ways: (repetition, vivid memories, anxiety interference, context effects, and suppression).
Repetition. The simple fact is that we tend to think more about emotionally charged situations - positive or negative - than about neutral ones. We repeat and organize exciting memories more than calm ones. For example, you can forget where you saw this or that movie, but if a fire breaks out while you are in the cinema, this case will dominate your thoughts for some time and you will describe this situation to your friends again and again, as well as again and again. think about it to yourself, thereby repeating and organizing information about it. Since we know that repetition and organization can improve long-term memory recall, it is not surprising that many researchers have found that memory for emotional situations is better than non-emotional ones (Neisser, 1982; Rapaport, 1942).
Vivid memories. The second way emotions affect memory is through vivid memories. Vivid memories are a vivid and relatively permanent fixation of the circumstances in which you learned about an important emotionally charged event. An example is the explosion of the Space Shuttle Challenger in 1986, which was witnessed by millions of television viewers. Many 30-year-olds remember exactly where they were when they heard about the Challenger disaster, and who told them about it, despite the fact that such details are usually quickly forgotten. Americans aged 40 and over may have vivid memories of the attempted assassination of Ronald Reagan in 1981, and those in their 50s and over may have similar memories of the assassination of John F. Kennedy and Martin Luther King Jr. in the 60s. It is noteworthy that even a report has been published showing that a hundred years ago, Americans had vivid memories of the assassination of Abraham Lincoln. When Colegrove (1899) interviewed 179 people, 127 of them were able to remember every detail of where they were and what they were doing when they heard about Lincoln's assassination.

What causes these memories? Scientists believe (Brown & Kulik, 1977) that events of extreme importance trigger a special memory mechanism that produces a record of everything that a person is experiencing at a given moment. It's like taking a snapshot with a flash, which is why such memories are called "bright memory". The idea of a special mechanism for emotional memories has proved controversial. The scientists discussing it point out that the reproducibility of vivid memories decreases over time, just like ordinary long-term memories. In one study, days after the Challenger bombing, people were asked where they had been and what they were doing when they learned of the disaster; 9 months later, the same questions were asked to the same people. Although these people retained unusually detailed memories of the event 9 months ago, some forgetting was noted during this period (McCloskey, Wible & Cohen, 1988). These results suggest that memories of national tragedies may also be normal memories. We remember them so vividly because we keep hearing and talking about them, as well as about other emotionally charged situations.
Researchers who support the idea of a special mechanism for emotional memories provide arguments in their favor. Most impressive is recent research into the biological basis of memory. His main idea is that the hormones epinephrine and noradrenaline are involved in the storage of emotional memories, while they are not involved in the storage of ordinary memories. Therefore, if the biochemical action of these two hormones is blocked, then it will be difficult for a person to remember emotional material, but it is not difficult to remember non-emotional material. This idea was tested in the following experiment. The subjects watched a slide show that was accompanied by either an emotional story (about a boy who was hospitalized for emergency surgery) or a non-emotional one (about a boy who came to the hospital to meet his father, who worked there). Before hearing these stories, one half of the subjects took the drug propranolol (Inderal), which blocks the action of adrenaline and norepinephrine, and the other half took a placebo. A week later, all subjects took a story recall test. The subjects who took the hormone-blocking drug recalled less of the emotional story than the subjects who took the placebo, but the two groups did not differ in recall of the neutral story. These results imply that emotional material is indeed stored in a different mechanism than neutral memories (Cahill et al., 1994).
We know which hormones are involved in this process, but which neural structures are affected by these hormones? In ch. 7, we noted that the amygdala is involved in the functioning of emotional memory. This is evidenced by the results of studies in recent years, which used brain scanning techniques. During the scan, subjects viewed images accompanied by an emotional narrative. The tonsil was activated, but the degree of activation varied from one individual to another. The greater the degree of activation shown by the subject, the better he was able to recall emotional information later. This fact provides strong evidence that the amygdala does indeed mediate the memorization of emotional material (Cahill et al., 1995).
Interference with playback due to anxiety. There are also cases where negative emotions suppress recall, which brings us to a third way in which emotions affect memory. Here is a description of experiences experienced at one time or another by many students:
“You are taking an exam that you are not too sure about. You can barely understand the first question, let alone answer it. Panic symptoms appear. The second question is not really difficult, but the anxiety triggered by the first question spills over here as well. By the time you look at the third question, it doesn't matter what they ask - even if it's your phone number. You can no longer answer. Panic has taken over you completely.
What happens to memory in this case? The inability to deal with the first question is alarming. Anxiety is often accompanied by extraneous thoughts like "I'll fail the exam" or "Everyone will think I'm dumb." Such thoughts fill the mind and interfere with any attempt to reproduce information pertaining to the question itself; maybe that's why memory fails. According to this view, anxiety does not in itself impair memory; it causes unnecessary thoughts or is associated with them, and already these thoughts interfere with reproduction, causing memory failure (Holmes, 1974).
context effects. Emotions can also affect memory through a kind of context effect. As we have noted, memory works best when the context in reproduction matches the context in encoding. Since our emotional state during memory is part of the context, if the material being remembered makes us sad, we may be best able to reproduce it when we are sad again. Experimenters have demonstrated this emotional context effect in the laboratory. The subjects agreed to keep a diary for a week, recording each emotional incident daily and noting whether it was pleasant or unpleasant. A week after they were handed the diaries for writing, the subjects returned to the laboratory and were hypnotized (they were specially selected for high hypnotizability). One half of the subjects were immersed in a pleasant mood, and the other half in an unpleasant one. All of them were asked to recall the incidents recorded in their diaries. In subjects who were in a pleasant mood, most of the recalled cases were qualified as pleasant experiences; in subjects in an unpleasant mood, most of the recalled cases were marked as unpleasant. As expected, the best reproduction was observed when the dominant emotions during reproduction matched those during encoding (Bower, 1981).
Suppression. So far, our discussion of the ways in which emotion influences memory has relied on the principles already discussed, namely repetition, interference, and the influence of context. The fifth view of emotion and memory, Freud's theory of the unconscious, contains new principles. Freud believed that some emotional experiences in childhood are so traumatic that to allow them to enter consciousness many years later would mean for the individual to become completely crushed by anxiety (this is different from the exam example, where anxiety is tolerable for consciousness). It is said that such traumatic experiences are stored in the unconscious or that they are repressed and can be reproduced only with a partial smoothing of the emotions associated with them. Suppression thus represents a total impossibility of reproduction: access to the required memories is actively blocked here. The concept of active blocking qualitatively distinguishes the suppression hypothesis from the notions of forgetting discussed above. (For a discussion of Freud's theory, see Chapter 13.)
Suppression is such a striking phenomenon that, of course, one would like to study it in the laboratory, but it turned out to be difficult to do. In order to induce true suppression in the laboratory, the experimenter would have to subject the subject to some extremely traumatic experience; this cannot be done for ethical reasons. Therefore, in the studies that were conducted, the subjects were subjected to only moderate disorders. The evidence from these studies is ambiguous with respect to the suppression hypothesis (Baddeley, 1990; Erdelyi, 1985).
In general, long-term memory is a system capable of storing information for many days, years, and even decades, usually in a form encoded in accordance with its meaning, although other codes are possible. The extraction of information from a given system is largely subject to interference; in many cases, "memory loss" is really nothing more than retrieval problems. The storage of information in the long-term memory system involves a process of consolidation, a process mediated by the hippocampal system. Many aspects of long-term memory are influenced by emotions; these influences may reflect processes such as selective rehearsal, extraction interference, contextual effects, or specific mechanisms such as flashbacks and repression.

Let's take a closer look at short-term and long-term memory.

As mentioned above, in short-term memory, the retention of material is limited to a certain, short period of time. The short-term memory of a person is connected with his actual consciousness.

Long-term memory is designed for long-term storage of information; it is not connected with the actual consciousness of a person and presupposes his ability at the right moment to recall what he once remembered. In contrast to SP, where recollection is not required (because what was perceived is still in the actual consciousness), in DP it is always necessary, because perceptual information is no longer in the realm of actual consciousness.

When using DP, remembering often requires certain volitional efforts, so its functioning is usually associated with will.

To maintain information in short-term memory, it is always necessary to maintain continuous attention to the memorized material during the entire time it is retained in memory; with long-term memorization, this is not necessary.

One of the possible mechanisms of short-term memorization is temporal coding, i.e. reflection of what is remembered in the form of certain, sequentially located symbols in the auditory and visual systems of a person. Often, in order to really remember something, they try to evoke a certain emotional reaction by association with it. Such a reaction can be considered as a special psychophysical mechanism that contributes to the activation and integration of processes that serve as a means of memorization and reproduction.

Consider the main characteristics of short-term memory. As already mentioned, its average volume is limited to 7 ± 2 units of integrated information. This volume is individual, it characterizes the natural memory of a person and tends to persist throughout life. First of all, it determines the amount of mechanical memory that functions without the active inclusion of thinking in the memorization process.

With the features of the CP, due to the limited scope of its volume, such a property as substitution is associated. It manifests itself in the fact that when the individual stable volume of a person's short-term memory is overflowed, the information that enters it again partially displaces the information already stored there. Subjectively, this can manifest itself, for example, in an involuntary switching of a person's attention from memorization to something else.

Short-term memory plays an important role in human life. Thanks to it, the most significant amount of information is processed, unnecessary information is eliminated, and as a result, long-term memory is not overloaded with unnecessary information. CP is of great importance for the organization of thinking; its material, as a rule, is the facts that are in the CP of a person.

This type of memory actively works in the process of human-to-human communication. It has been established that when people who meet for the first time are asked to talk about their impressions of each other, to describe those personal characteristics that they noticed during the meeting, then on average, as a rule, the number of traits that corresponds to the volume of the CP, i.e., is called. e. 7±2.

Without CP, the normal functioning of long-term memory is impossible. Only what was once in the CP can penetrate into the latter and be deposited for a long time. In other words, the CP acts as a kind of filter that lets the necessary information into the DP, while simultaneously performing a strict selection in it.

One of the main properties of CP is that this type of memory, under certain conditions, also has no time limits. This condition consists in the possibility of continuously repeating a series of words, numbers, etc., just heard. To maintain information in the CP, it is necessary to maintain activity aimed at memorization, without diverting attention to another type of activity, complex mental work.

Clinical studies related to memory disorders show that the two types of memory - CP and DP - do exist as relatively independent. For example, with such a disorder, which is called retrograde amnesia, the memory of recent events suffers mainly, but the memories of those events that took place in the distant past are preserved. With another type of disease - anterograde amnesia - both CP and DP remain preserved. However, the ability to enter new information into the DP suffers.

However, both types of memory are interconnected and work as a single system. One of the concepts showing their joint work was developed by American scientists R. Atkinson and R. Shifrin. It is schematically presented in Fig. 2

Rice. 2.

In accordance with this theory, the DP is practically unlimited in volume, but limited in the possibility of arbitrary recall of the information stored in it. In addition, in order for information to get into the storage of the DP, it is necessary that certain work be done on it even at the time when it is in the CP.

In many life situations, the processes of CP and DP work almost in parallel. For example, when a person sets himself the task of remembering something that obviously exceeds the capabilities of his CP, he often consciously or unconsciously resorts to the method of semantic grouping of material, which makes it easier for him to memorize. Such a grouping, in turn, involves the use of DP, referring to past experience, extracting from it the knowledge and concepts necessary for generalization, ways of grouping the memorized material, reducing it to a number of semantic units that do not exceed the volume of the CP.

The transfer of information from the CP to the DP usually causes difficulties, because, in order to do this, you need to comprehend and structure in a certain way, connect in your imagination new information with those that are already stored in the DP. But there are unique cases when this is done relatively easily by a person. One such case was described by A.R. Luria in his work "A Little Book of Great Memory". The features of the memory of a certain Sh. were examined, and it was found that “it was indifferent to him whether meaningful words, meaningless syllables, numbers or sounds were presented to him, whether they were given orally or in writing; he only needed one element of the proposed row was separated from another by a pause of 2-3 seconds.

As it was found out later, Sh.'s memory mechanism was based on eidetic vision, which he had especially developed. After the presentation of the material, Sh. continued to see it in the absence of the material itself and was able to restore in detail the corresponding visual image after a long time (some experiments were repeated after 15-16 years). For the average person, it is this point of recollection that is usually the problem.

Let us now consider the features and mechanisms of operation of the DP. She usually joins the case not immediately after the material has been perceived, but after at least a few minutes. When information is transferred from the CP to the DP, it is usually recoded again and included in the semantic structures and connections that already exist in the DP. In contrast to CP, in the long term this process is neither auditory nor visual. Rather, it is based on thinking, on the conscious attribution to the memorized of a certain semantic meaning known to the memorizer. Thus, DP has a semantic organization.

Speech plays an important role in DP. What can be expressed in words is usually remembered more easily and better than what can only be perceived visually or by ear. At the same time, if words act not just as a verbal replacement for the memorized material, but are the result of its comprehension, then this is the most productive.

Preservation and recall as mnemonic processes have their own characteristics. A person's poor memory may be due to difficulty remembering, rather than remembering as such. Difficulties that arise when remembering are often associated with the fact that at the right time the necessary stimulus-means for remembering were not at hand. The richer the stimuli-means that a person has for remembering, the more they are available to him at the right time, the better is arbitrary recall. At the same time, two factors increase the likelihood of successful recall: the correct organization of the memorized information and the recreation of conditions identical to the conditions under which the material was memorized.

One of the effective ways of structuring memorization is to give the memorized material a structure of the "tree" type. In such a structure, at the very top is a keyword that conveys the most general meaning of the text. Below are keywords that convey the meaning of individual parts of the text. Then keywords that convey the meaning of individual sentences. At the very bottom of the structure is the actual memorized text. To recall the text, it is enough to first come up with the "upper" keyword, and then moving to the lower levels of the structure, remember the entire text.

The effectiveness of recall is sometimes reduced by interference, i.e. mixing of some materials with others, some memory schemes with others, connected with completely different materials. Most often, interference occurs when the same memories are associated in memory with the same events and their appearance in consciousness gives rise to the simultaneous recall of competing (interfering) events.

The memory of the material is also affected by the emotions associated with it, and depending on the specifics of the emotional experiences associated with the memory, this influence can manifest itself in different ways. The brighter the emotions associated with the event, the easier the recall. Positive emotions tend to promote recall, while negative emotions hinder it. It has been experimentally proven that artificial re-creation of the emotional states accompanying the moment of remembering improves memory.

Long-term memory with conscious access is characterized by the pattern of forgetting: everything unnecessary, secondary, as well as a certain percentage of necessary information is forgotten.

To reduce forgetting, you need to:

1) understanding, comprehension of information (mechanically learned, but not fully understood information is forgotten quickly and almost completely - curve 1 on the graph);

2) repetition of information (the first repetition is necessary 40 minutes after memorization, since after an hour only 50% of mechanically memorized information remains in memory).

It is necessary to repeat more often in the first days after memorization, because these days the losses from forgetting are maximum, it is better like this: on the first day - 2-3 repetitions, on the second day - 1-2 repetitions, on the third - the seventh day, 1 repetition, then 1 repetition with an interval of 7-10 days. 30 repetitions in a month is more effective than 100 repetitions in a day. Therefore, systematic study, without overload, memorization in small portions during the semester with periodic repetitions after 10 days is much more effective than concentrated memorization of a large amount of information in a short session, causing mental and psychic overload and almost complete forgetting of information a week after the session.

Rice. 3. Ebbinghaus forgetting curve: a) meaningless material; b) logical processing; c) on repetition

Forgetting largely depends on the nature of the activity immediately preceding memorization and occurring after it. The negative impact of pre-memorization activity is called proactive inhibition. The negative effect of the activity following memorization is called retroactive inhibition, it is especially pronounced in those cases when, after memorization, an activity similar to it is performed or if this activity requires significant effort.

Own internal memory is the most important mental process. Throughout life, the human brain perceives, processes, stores and reproduces various information, some of which is not stored in memories for long, the other part can be reproduced even after several years. What are the characteristics of the memorization process related to? This is primarily due to the fact that a person has 2 completely different types of memory:

long-term;
short-term.

It is on these types that it depends what information will be stored in the cerebral cortex for only a few minutes, and what will be “imprinted” there for many years.

In psychology, there is an opinion that the process of memorization and assimilation, as well as the volumes that short-term and long-term memory can hold, is largely influenced by genetic predisposition.

Characteristics of short-term memory

This type of memory is one of the mental processes, which is characterized by a time-limited storage of information (no more than 30 seconds) and a limited retention of elements (5-9 units). Information is entered into short-term storage with the help of sensory sensations. An important point contributing to the "selection" of the material is the focus of a person's attention on certain objects.

At the same time, only the knowledge that is relevant at a given time is stored. After this knowledge is no longer relevant for a person, they are usually forgotten or transferred to long-term memory.

This type of memory is especially sensitive to external influences. So, with any distractions, a person can quickly forget the information that he wanted to remember.

Features of short-term memorization

Despite the fact that short-term memory stores data for a relatively short period of time, it includes important processes for processing the resulting material:

coding. In order for a certain information block to get into short-term storage, it must be of direct significance to a person. Only significant information is consciously perceived and remembered, albeit for a rather short period of time. For example, many will not remember verbatim the entire conversation with the boss, but will reproduce only that part of it that was of value and meaning.
storage. The only feature of memory storage is the limitation of objects held in memory. So, short-term memory in children is able to simultaneously store no more than 5-6 elements (numbers, words, images) at the same time. In adults, the volume of memorized elements is 7-9. However, it is necessary to take into account the individual characteristics of memorization.

In psychology, one of the varieties of short-term memory is considered RAM. This type is designed to store a specific material in a predetermined time range.

Operational memorization is largely determined by tasks that are significant for a person at one time or another. For example, working memory helps schoolchildren to memorize the material for tomorrow's lesson, after which the information can be transferred to a longer storage or even be squeezed out.

What is long term memory?

This type of memory is considered a more reliable storage of various information. In most cases, it stores information that has personal meaning for a person or that has found an emotional response in his soul. The amount of material memorized and the time of its storage can be completely different for all people.

A little about genetics

Psychology distinguishes another type of memory, which is usually referred to as long-term memory - genetic memory. It is designed to store information about our ancestors at a subconscious level. Scientists believe that it is genetic memory that determines a person's behavior, his character and even fate.

Some experts believe that this type of memorization is limited to the age of 2-3 years. However, other researchers believe that genetic memory stores information throughout a person's life. Moreover, such a “memory trace”, albeit subconscious, is the fundamental principle of the concept of “long-term memory”, which consists in the long-term storage of valuable information.

Relationship between short-term and long-term memory

There is a close relationship between these concepts. Those knowledge that are of particular interest to a person pass into long-term memory. And then the necessary information blocks are periodically extracted from it, which fall into short-term memory.

The interaction of these types of memory is constantly observed and it characterizes the quality of memorization and assimilation of certain information, as well as the ability of a person to extract and reproduce previously acquired knowledge.

Thus, long-term and short-term storage of information perform important functions in the memorization and reproduction of material. Short-term well lends itself to training and development when performing special exercises. Long-term can also be developed, but this requires much more time and effort.

Regardless of the purpose for which a person remembers this or that information, it will certainly be initially stored in short-term memory. In the future, the data either loses its relevance and is forced out, or transferred to long-term storage so that it can be reproduced at the right time. Those who wish to develop their memory need to constantly exercise in memorizing material, the ability to reproduce it after a while.

Article author: Lapinskaya Lyudmila

Long-term memory is the most important and most complex memory system. If we hold an event for several minutes, it moves into long-term memory.

Short and long term memory

Short-term memory is a store for small pieces of information. If it is not of great importance, then it is immediately thrown out of storage. does not allow you to remember useless dates and phone numbers, but it is thanks to her that we build our thought processes.

Long-term memory stores only important information. It is in this repository that everything you know about the world is located. Wherever you are, this knowledge always stays with you. Experts say that long-term memory is endowed with an unlimited volume. So, the more a person knows, the easier it is for him to memorize new data. Long-term memory cannot be filled to capacity.

It is worth saying that there is also a short-term memory and long-term memory. If a person performs an action, for example, makes calculations, he performs them in parts, keeping in mind some intermediate results, and in such cases this type of long-term memorization works.

Types of long-term memory

Implicit memory is formed in the brain unconsciously and does not involve verbal expression. This is the so-called "hidden" type of memory.
Explicit memory is created consciously. A person consciously holds it, and if desired, can voice the memorized information.

Experts argue that both types of long-term memory can conflict with each other. For example, in order to manifest our subconscious memory, we must stop thinking and vice versa. The conflict between these two species can result in trouble.

Let's take an example for better understanding. A person remembers thanks to the subconscious memory how to drive a car. But if at the moment of driving you think and focus on something more significant and serious for him, there is a risk of getting into an accident. Based on this, it is important to learn how to use the two types of long-term memory wisely. It is not easy to engage them at the same time, but it is necessary to learn how to highlight the one that is most important at the moment.

How to improve long-term memory?

Long-term memory allows us to live a full life, learn valuable lessons and fulfill our plans. Try to train your memory so that it does not let you down at the right time. For long-term storage of information, use the above tips.

One of the mental functions and types of mental activity, designed to store, accumulate and reproduce information. The ability to store information about the events of the external world and the reactions of the body for a long time and repeatedly use it in the sphere of consciousness to organize subsequent activities.

There are different types of memory:

by sensory modality - visual (visual) memory, motor (kinesthetic) memory, sound (auditory) memory, taste memory, pain memory;
by content - figurative memory, motor memory, emotional memory;
on the organization of memorization - episodic memory, semantic memory, procedural memory;
according to temporal characteristics - , ultra-short-term memory;
by the presence of a goal - arbitrary and involuntary;
by availability of funds - indirect and non-mediated;
according to the level of development - motor, emotional, figurative, verbal-logical.

Features of the functioning of memory

Memory Properties

Accuracy
Volume
The speed of memorization processes
The speed of forgetting processes

Patterns of memory

Memory is limited. The success of reproducing a large amount of material depends on the nature of the distribution of repetitions in time. There is such a pattern as the forgetting curve.

Memory laws:

Law of Interest- Interesting things are easier to remember.
Law of comprehension- The deeper you become aware of the memorized information, the better it will be remembered.
Installation Law- If a person gave himself the installation to remember information, then memorization will happen easier.
Law of Action– Information involved in activities (i.e. if knowledge is put into practice) is remembered better.
Law of context- With the associative linking of information with already familiar concepts, the new is absorbed better.
Law of inhibition– When studying similar concepts, the effect of “overlapping” the old information with the new one is observed.
The Law of Optimal Row Length- The length of the memorized row for better memorization should not greatly exceed the volume.
edge law- The information presented at the beginning and at the end is best remembered.
Law of repetition- Information that is repeated several times is best remembered.
Law of incompleteness– Incomplete actions, tasks, unsaid phrases, etc. are best remembered.

Mnemotechnical methods of memorization

The formation of semantic phrases from the initial letters of the memorized information.
Rhyming.
Memorization of long terms or foreign words with the help of consonants.
Finding bright unusual associations (pictures, phrases) that are connected with memorized information.
Cicero's method on spatial imagination.
Aivazovsky's method is based on the training of visual memory.
Methods for memorizing numbers:
- patterns;
- familiar numbers.

Memory processes

Memorization is a memory process through which traces are imprinted, new elements of sensations, perception, thinking or experience are introduced into the system of associative links. The basis of memorization is the connection of material with meaning into one whole. The establishment of semantic connections is the result of the work of thinking on the content of the memorized material.
Storage - the process of accumulation of material in the structure of memory, including its processing and assimilation. Preservation makes it possible for a person to learn, develop his perceptual (internal assessments, perception of the world) processes, thinking and speech.
Reproduction and recognition is the process of updating the elements of past experience (images, thoughts, feelings, movements). A simple form of reproduction is recognition - the recognition of a perceived object or phenomenon as already known from past experience, the establishment of similarities between the object and its image in memory. Reproduction is voluntary and involuntary. With an involuntary image pops up in the head without the efforts of a person.

If there are difficulties in the process of reproducing, then the process is in progress. Selection of elements necessary from the point of view of the required task. The reproduced information is not an exact copy of what is imprinted in memory. Information is always being transformed, rearranged.

Forgetting is the loss of the ability to reproduce, and sometimes even in recognizing what was previously memorized. Most often we forget what is not significant. Forgetting can be partial (reproduction is not complete or with) and complete (impossibility of reproduction and recognition). Distinguish between temporary and long-term forgetting.

neurological memory

Memory is a set of activities that include both biological-physiological and mental processes, the implementation of which at the moment is due to the fact that some previous events, close or distant in time, have significantly modified the state of the organism. (C. Flores).

Memory means the use and participation of previous experience in the present. From this point of view, memory, both at the moment of consolidation and at the moment of its reproduction, is an activity in the full sense of the word. (Zinchenko).

Visual (visual) memory is responsible for the preservation and reproduction of visual images.
Motor memory is responsible for storing information about motor functions. For example, a first-class baseball player throws the ball superbly, in part due to the memory of motor activity during past throws.
Episodic memory is the memory of events that we participated in or witnessed (Tulving, 1972). Examples of it might be remembering how you celebrated your seventeenth birthday, remembering the day of your engagement, remembering the plot of a movie you saw last week. This type of memory is characterized by the fact that the memorization of information occurs without visible effort on our part.
Semantic memory is the memory of facts such as the multiplication table or the meaning of words. You probably won't be able to remember where and when you learned that 6547 x 8791 = 57554677, or from whom you learned what the word "stock" means, but nevertheless this knowledge is part of your memory. Perhaps you will be able to remember all the torment that the study of the multiplication table brought you. Both episodic and semantic memory contain knowledge that can be easily told and declared. Therefore, these two subsystems form part of a larger category called declarative memory.
Procedural memory, or remembering how to do something, has some similarities with motor memory. The difference is that the description of the procedure does not necessarily imply the possession of any motor skills. For example, in your school years, you were supposed to be taught how to work with a slide rule. This is a kind of "knowing how", which is often contrasted with descriptive tasks that involve "knowing what".
Topographic memory - the ability to navigate in space, recognize the path and follow the route, recognize familiar places. Topographic cretinism can be caused by numerous disorders, including difficulties with perception, orientation, and memory.

Classification of types of memory according to criteria

figurative memory
verbal-logical memory
sensory memory
emotional memory

Time

operational
intermediate

Organization of memorization

episodic memory
semantic memory
procedural memory

Properties of human memory

The pioneer in the study of human memory is Hermann Ebbinghaus, who experimented on himself (the main technique was to memorize meaningless lists of words or syllables).

Long-term and short-term memory

Physiological studies reveal 2 main types of memory: short-term and long-term. One of the most important discoveries of Ebbinghaus was that if the list is not very large (usually 7), then it can be remembered after the first reading (usually the list of elements that can be remembered immediately is called the size of short-term memory).

Another law established by Ebbinghaus is that the amount of material retained depends on the time interval from the moment of memorization to verification (the so-called "Ebbinghaus curve"). The positional effect was discovered (occurring if the stored information exceeds short-term memory in volume). It lies in the fact that the ease of remembering a given element depends on the place it occupies in a row (the first and last elements are easier to remember).

It is believed that short-term memory is based on electrophysiological mechanisms that support connected neuronal systems. Long-term memory is fixed by structural changes in individual cells that are part of neuronal systems, and is associated with chemical transformation, the formation of new substances.

short term memory

Short-term memory exists due to temporal patterns of neural connections emanating from areas of the frontal (especially dorsolateral, prefrontal) and parietal cortex. This is where sensory information comes in. Short-term memory allows you to remember something after a period of time from a few seconds to a minute without repetition. Its capacity is very limited. George Miller, while working at Bell Laboratories, performed experiments showing that the capacity of short-term memory is 7 ± 2 objects (the title of his famous work is “The Magic Number 7 ± 2”). Modern estimates of short-term memory capacity are somewhat lower, typically 4-5 objects, and it is known that short-term memory capacity increases through a process called "chunking" (grouping of objects). For example, if you present the string

FSBKMSMCHSEGE

a person will be able to remember only a few letters. However, if the same information is presented differently:

FSB CMS Ministry of Emergency Situations Unified State Examination

a person will be able to remember much more letters because he is able to group (combine into chains) information about the semantic groups of letters (in the English original: FBIPHDTWAIBM and FBI PHD TWA IBM). Herbert Simon also showed that the ideal size for chunks of letters and numbers, whether meaningful or not, is three units. Perhaps in some countries this is reflected in the tendency to present a telephone number as several groups of 3 digits and a final group of 4 digits divided into 2 groups of two.

There are hypotheses that short-term memory relies mainly on an acoustic (verbal) code for storing information and, to a lesser extent, on a visual code. Konrad (1964) showed that subjects have more difficulty remembering sets of words that are acoustically similar.

Modern studies of ant communication have proven that ants are able to memorize and transmit information up to 7 bits. Moreover, the influence of possible grouping of objects on the message length and transmission efficiency is demonstrated. In this sense, the law "Magic number 7 ± 2" is also fulfilled for ants.

long term memory

Storage in sensory and short-term memory usually has a hard-limited capacity and duration, that is, information remains available for some time, but not indefinitely. In contrast, long-term memory can store much more information for a potentially infinite amount of time (a lifetime). For example, some 7-digit phone number can be stored in short-term memory and forgotten after a few seconds. On the other hand, a person can remember by repeating a phone number for years to come. In long-term memory, information is encoded semantically: Baddeley (1960) showed that after a 20-minute pause, subjects had significant difficulty recalling a list of words with similar meanings (eg, large, huge, large, massive).

Long-term memory is supported by more stable and unchanging changes in neural connections widely distributed throughout the brain. is important in consolidating information from short-term to long-term memory, although it does not appear to store information itself. Rather, the hippocampus is involved in changing neural connections after 3 months of initial learning.

One of the primary functions is the consolidation of information. It is possible to show that memory depends on a sufficient period between training and testing. Moreover, the hippocampus reproduces the activity of the current day during sleep.

Memory disorders

A large amount of knowledge about the structure and operation of memory, which is now available, was obtained by studying the phenomena of its violation. Memory disorders - amnesia - can be caused by various reasons. In 1887, the Russian psychiatrist S. S. Korsakov, in his publication On Alcoholic Paralysis, first described the picture of gross memory disorders that occur with severe alcohol poisoning. The discovery called "Korsakov's syndrome" is firmly established in the scientific literature. Currently, all memory disorders are divided into:

Hypomnesia - weakening of memory. Memory impairment may occur with age and / and as a result of any brain disease (sclerosis of cerebral vessels, epilepsy, etc.).
Hypermnesia - an abnormal sharpening of memory compared to normal indicators, is observed much less frequently. People with this feature forget events with great difficulty (Shereshevsky)
Paramnesias, which involve false or distorted memories, as well as the displacement of the present and the past, the real and the imagined.

Particularly stands out childhood amnesia - loss of memory for the events of early childhood. Apparently, this type of amnesia is associated with the immaturity of the hippocampal connections, or with the use of other methods of encoding "keys" to memory at this age.

Mythology, religion, philosophy about memory

In ancient Greek mythology, there is a myth about the river Lethe. Lethe means "forgetfulness" and is an integral part of the realm of death. The dead are those who have lost their memory. On the other hand, some who were favored, among them Tiresias or Amphiaraus, retained their memory even after their death.
The opposite of the Lethe River is the Goddess Mnemosyne, the personified Memory, the sister of Kronos and Okeanos - the mother of all muses. She has Omniscience: according to Hesiod (Theogony, 32 38), she knows "everything that was, everything that is, and everything that will be." When the Muses take possession of the poet, he drinks from the source of knowledge of Mnemosyne, which means, first of all, that he touches the knowledge of the “origins”, “beginnings”.
According to the philosophy of Anamnesis - recollection, recollection - a concept that describes the basic procedure of the process of cognition.