The Emotional memory Refers to the ability of people to set memories from emotions.
In this sense, multiple studies have shown how memory-related brain structures are closely associated with regions of the brain that modulate emotions.
In fact, emotions Are intimately linked to the memory And it is considered that the emotional content of the events influences the later memory.
These discoveries that the neuroscience has developed during the last years show that the information that is acquired emotionally is remembered in a different way than the one that is acquired neutrally.
Faced with this close relationship between emotion and memory, a new memory structure has emerged, known as emotional memory.
The aim of this article is to review the characteristics of emotional memory and present the data that we have today about the relationship between emotion and memory.
Characteristics of Emotional Memory
Emotional memory is a very specific human capacity characterized by developing memory of events through the emotional impact experienced.
This concept postulates that emotionally significant events are held differently than neutral events.
Specifically, it is generally supported by the idea that emotional events are remembered better and more easily than the most trivial events.
For example, a traumatic event during childhood such as a traffic accident or a fight with a partner is often remembered much more specifically during adulthood than trivial events such as what was eaten last week.
This dichotomy of memories refers to selective memory. People do not remember all the information in the same way. In this sense, events experienced emotionally seem to be better remembered than the rest.
In fact, multiple research shows that the greatest memory of emotionally intense experiences is due to greater ease of acquisition, greater maintenance over time, and greater resistance to extinction.
Positive emotions and negative emotions in memory
Emotional memory responds to both Positive emotions as Negative . That is, events lived emotionally (whatever their character) seem to be remembered differently from neutral or trivial experiences.
This is because Brain structures That modulate the positive emotions and those that modulate the negative emotions are the same.
Thus, the brain mechanism that explains the existence of emotional memory lies in the association between the structures of emotion and the regions of memory.
Highly aversive or traumatic events can provoke a particularly strong and consolidated memory. The person can remember these events in a frequent and detailed way throughout his life.
An example of this type of memories would be the traumas suffered during childhood, which can appear repeatedly and be remembered permanently during the adult stage.
Finding similes with positive emotions is somewhat more complex. There are people who can remember in great detail the day of their wedding or the birth of their children, but often the memory is less intense than that of negative events.
This fact is explained by the intensity of emotion. In general, negative events cause more emotional disturbance, so the emotions experienced at those times are usually more intense.
In this way, traumatic events can be more easily inserted into emotional memory. But this does not mean that positive events can not. They also do, though usually less markedly because of their lesser emotional intensity.
Structures of emotional memory
The structure of the main brain that is responsible for performing memory processes and facilitates recall is the hippocampus. This region is located in the temporal cortex and forms part of the limbic system .
For its part, the brain region responsible for giving rise to emotional responses is the amygdala .
This structure consists of a set of nuclei of Neurons Located in the depths of the temporal lobes and also part of the limbic system.
In this way, both structures (amygdala and hippocampus ) Are constantly connected. Likewise, their connection seems to have a special relevance in the formation of emotional memories.
This fact postulates the existence of two different systems of memory. When people learn neutral information (such as reading a book or learning the subject matter), the hippocampus is responsible for building memory without involvement of the amygdala.
However, when the elements to remember contain a certain emotional charge, the amygdala comes into play.
In these cases the first formation of the memory is made in the amygdala, which acts as a storehouse of memories associated with emotional events. In this way, emotional memory does not start in the hippocampus as the rest of memories.
Once the amygdala has encoded the emotional element and formed the memory, it transmits the information through synaptic connections to the hippocampus, the place where emotional memory is stored.
Influence of emotion in memory
Emotional memory presents different characteristics and different brain recording mechanisms due to the performance of emotion.
In fact, it is the emotions that motivate the information to access the brain through different structures and consolidate it in a more intense way.
Thus, emotional processes modify the functioning of memory giving rise to the appearance of emotional memory.
These modifications are explained by the amygdala-hippocampal relationship and are performed both in the codification and in the consolidation of the information.
1- Emotional coding
The first cognitive function that comes into play at the time of form a memory is attention. In fact, without adequate attention the brain is unable to properly perceive the information and store it in its previous one.
In this sense, the first modification that the emotions make is already detected in the way the information is perceived.
The emotional responses immediately provoke an alteration of the physical and psychological functions of the person. Thus, when an individual experiences an emotion, both physical and psychological elements related to attention increase.
This fact allows the attention given to the stimulus to be higher, so that the information is more easily captured and later stored more satisfactory.
2- Emotional consolidation
The second phase of the generation of emotional memories consists in the retention or consolidation of information in the brain structures.
If the information captured by the senses is not consolidated in the brain, it disappears little by little and the memory does not remain (it is forgotten).
The storage of information in brain structures is not automatic, but a slow process, which is why it is often complex to retain specific long-term information.
However, emotional information seems to have a much shorter consolidation time. That is, it can be stored in the brain structures much faster.
This fact causes that the chances that the emotionally intense events are remembered and maintained over time are much higher.
Influence of memory on emotion
The relationship between memory and emotion is not unidirectional but it is bidirectional. This means that in the same way that emotion can affect memory (emotional memory), memory can also affect emotion.
This association has been specially studied by the neuropsychologist Elisabeth Phelps when analyzing the interaction between hippocampus and amygdala.
When the hippocampus recovers emotionally intense information, it can interact with the amygdala to produce the emotion that accompanies it.
For example, when a person remembers a highly traumatic event, he immediately experiences the emotions associated with that event.
Thus, memory can provoke emotional responses, just as experiencing emotions can alter memory formation.
The hippocampus and amygdala are interconnected brain structures that allow the emotional components to be related to the mnemic elements in a constant way.
Function of emotional memory
The association between emotional structures and regions of memory is not free. In fact, the relationship between hippocampus and amygdala fulfills an important adaptive function.
When people are in dangerous situations they react with an emotional response. This response allows a greater activation of both the psychological state and the physical state of the individual.
For example, if someone visualizes that a dog is going to attack him, he experiences an emotional response of fear. This response allows you to stress the body, increase attention and focus all the senses on the threat.
In this way, the emotional response prepares the person to respond adequately to a threat.
However, the process of defense and survival of human beings does not end there. The brain prioritizes the storage of emotionally intense events through the association amygdala-hippocampus so that these can be remembered with ease.
Thus, emotional memory is a human capacity that is closely related to the survival of the species. For people it is much more useful to remember emotionally intense elements than neutral aspects because they are usually more important.
Studies on emotional memory
Emotional memory functions as a filter system. It is in charge of selecting the facts that by their meaning are most relevant and keeps them in memory in a more intense and lasting.
From this evolutionary point of view, it is postulated that the human brain would be able to correctly remember aversive experiences even though they have rarely appeared.
In this sense Garcia & Koeling demonstrated in 1966 that emotional memory can be formed even with a single presentation. Specifically, learning such as gustatory aversion or fear conditioning can be acquired with a single essay.
These experiments demonstrate the high capacity of emotional memory. This enables the formation of lasting memories in an extremely fast and simple way, fact that does not happen with"non-emotional memory".
Other research on emotional memory has focused on analyzing the mechanisms involved in the relationship between emotion and memory.
At the brain level it seems that the structures involved in the generation of emotional memory are the amygdala and the hippocampus. However, there seem to be more related factors.
Neuroendocrine effects of stress and memory
Studies on the neuroendocrine effects of stress and its relationship to the formation of memories of stressful experiences have provided relevant data on emotional memory.
When a person is subjected to situations with high emotional content releases a large amount of adrenal hormones. Mainly adrenalin And glucocorticoids.
Several investigations have focused on analyzing the effect of these hormones and have been shown to be closely linked to the memory-emotion interaction.
In this sense, Beylin & Shors showed in 2003 that the administration of an adrenal hormone known as corticosterone prior to performing a learning task, modulated memory and increased memory.
Also, De Quervain showed that the modulation of memory varies according to the moment and the intensity with which the hormones are released. In this way, the glucocorticoids facilitate the memory of the people.
Subsequently, a study conducted by McCaug in 2002 showed that these hormonal effects occur through central noradrenergic mechanisms. That is, through the action of the brain amygdala.
The presence of glucocorticoids in the blood causes a greater stimulation of the amygdala. When the amygdala is active, it begins to participate directly in the formation of memories.
Thus, when these hormones are administered to the blood, the memory begins to function through the mechanisms of emotional memory, which is why memory is intensified and learning becomes more powerful and consolidated.
References
- Beylin, A. V. & Shors, T. J. (2003). Glucocorticoids are necessary for enhancing the acquisition of associative memories after acute stressful experience. Hormones and Behavior, 43 (1), 124-131.
- Christianson, S.A. (1992). Emotional stress and eyewitness memory: A critical review. Psychological Bulletin, 112 (2), 284-309.
- De Quervain, DJ-F., Roozendaal, B. & McGaugh, J.L. (1998). Stress and glucocorticoids impair retrieval of long-term spatial memory. Nature, 394, 787-790.
- García, J. & Koelling, R.A. (1966). Relation of cue to consequence in avoidance learning. Psychonomic Science, 4, 123-124.
- McEwen, B. S. & Sapolsky, R.M. (1995). Stress and cognitive function. Current Opinion in Neurobiology, 5, 205-216.
- McGaugh, J. L. & Roozendaal, B. (2002). Role of adrenal stress hormones in forming lasting memories in the brain. Current Opinion in Neurobiology, 12, 205-210.