The findings imply that when subjected to extreme stress, the brain might engage a separate pathway to produce and repress memories. Furthermore, the study demonstrates that there are various paths for memory storage. This means that different methods may be used by the brain to remove unwanted memories that have become too painful to forget.
When the brain develops memories in a specific emotion or condition, such as under stress or trauma, such memories become unavailable in a normal state of awareness. Suppressed memories are best recalled when the brain is in that condition again. For example, if a person experiences intense fear while their memory system is active, they will likely forget the incident.
In general, the more significant the experience, the stronger its memory trace. This means that events in one's life have greater potential to be remembered when they cause feelings of anxiety or fear. For this reason, memories for traumatic events can be difficult or impossible to access by their owners. The more time that passes after the event, the less emotional energy there is associated with it. This may explain why some people cannot recall incidents from their past, while others can repeat certain details about them.
However, even with very strong emotions attached to them, some memories are still able to escape attention and recollection. This shows that our brains are capable of filtering out certain information, whether it be because we no longer need it or because it is simply too painful to think about.
It has been suggested that memories can be blocked out in two ways: consciously or unconsciously. Conscious blocking out would require you to be aware that something bad happened, but you decided not to remember it.
Scientists believe they have discovered why. For the first time, experimental rat studies have shown the brain process that converts unpleasant experiences into long-lasting memories. The research also reveals how blocking this mechanism prevents rats from forming painful memories.
The study, published in Science magazine, showed that when glutamate - a chemical in the brain responsible for memory and learning - interacts with another protein, it creates a cascade of reactions that transforms an innocuous experience into a memory that will always cause pain. Glutamate is like a key that opens the door to the memory storehouse inside our brains. Without its interaction with this other protein, it can't do so.
The researchers blocked this protein using an enzyme called gamma-secretase. They knew this would prevent the formation of painful memories, because previous work had already shown this enzyme to be necessary for creating long-term memories. Thus, they expected the rats to not form pain memories after their experiences.
But what they found was surprising: Even though these rats were given pain shocks every time they entered a room where they'd previously been burned by hot water, they didn't develop any long-lasting feelings toward the heat source. They didn't run away from it or avoid places where it had been set off before. They simply didn't remember that the water was hot.
The ability to perceive and recall fear is critical to the evolution of the human species. This is why terrible memories are so difficult to forget. According to recent study, positive and negative memories are really based in distinct sections of the amygdala, in different groupings of neurons. These groups of neurons are called "modules" for their role in storing specific types of information.
However, it isn't just our perception that makes these memories hard to erase. It also depends on which modules are activated when we try to forget them. If a memory module is active when we try to suppress another one, then it will still be available even if we consciously don't think about it.
This means that these bad memories will always be with us somewhere inside our minds. However, with modern technology such as DBT (Dialectical Behavior Therapy), we can identify which modules are responsible for which memories and then work on suppressing them instead. With time, these memories will become less intense and intrusive, and eventually, you could even try to remember them without feeling afraid.
Many experts and mental health specialists believe that it is possible to repress and subsequently regain memories, but they also agree that this is extremely unlikely. Some specialists feel that memories may be repressed, but once gone, they cannot be regained. Others think that memories may be altered or distorted, so they can be forgotten but not lost.
The concept of memory repression was first proposed by Sigmund Freud in his book The Psychopathology of Everyday Life. He suggested that certain unpleasant memories are so disturbing that we would be better off without them. Therefore, we suppress these memories from our conscious minds by creating a new memory that replaces the original one. According to this theory, we retain some awareness of the suppressed memory but it becomes dissociated from our ordinary consciousness.
In 1956, John Anderson wrote a paper titled "A Mechanism for the Suppression of Unwanted Memories" in which he described an experiment he had performed with rats. In this experiment, two groups of rats were given electric shocks every time they entered a particular room. One group was also given the opportunity to escape from this situation by entering another room where they could find shelter. After several days, when all the animals were completely familiar with the rooms and corridors, their memories were tested. It was found that both groups remembered having entered the shock-free room, but only those animals that had escaped punishment forgot the other room entirely.