Long-term memory stands for the ability of the brain which enables us to remember and retrieve everything we’ve learned and experienced in a long period of time, sometimes – in a whole lifetime. It provides storage for both skills and information.
The information received from the sensory stimuli can be encoded as semantic (meaning), visual (images), as well as acoustic (sound) memories.
Where Is the Long Term Memory Stored In the Brain?
The hippocampus is the area of the brain responsible for the consolidation and processing of short term memories so that they can be stored in the long term memory of our brain. From the hippocampus, the long term memories are integrated into the structures of the cerebral cortex.
What Are the Types of Long Term Memory?
According to the type of information stored in the long term memory, this type of memory can be divided into:
- Implicit memory
- Explicit (declarative) memory
Implicit Memory
Implicit memory is an unintentional, automatic, and unconscious memory of everything we have learned how to do or a type of memory that’s used for storing simple facts and events. It starts with learning skills and mastering a task.
This type of memory can be further subdivided into:
- Procedural memory
- Priming
- Classical conditioning
Procedural Memory
As the name implies, this type of memory stores data on how to perform certain procedures, actions, and skills, like riding a bike, baking a cake, playing the guitar, etc.
The cerebellum plays a big role in the processing of procedural memory.
Priming of Memory
The priming of memory is an effect of the implicit memory which occurs when a stimulus triggers a response to other stimuli, i.e. a change in behavior due to a previous experience.
With this type of activation, the information stored in the long term memory becomes more easily assessed. For instance, if we receive a welcome cookie at a restaurant, we would expect to receive it (or will recall the memory of it) at all other restaurants we visit after.
Classical Conditioning of Memory
This is a type of implicit long term memory that denotes the way we learn to associate stimuli, i.e. sound and light with food.
In most cases, when people think of lemon, that image triggers salivation in their mouths. This is a naturally occurring reaction to the stimuli, which is labeled as classical conditioning of memory.
Explicit (Declarative) Memory
This is a type of long term memory that stores consciously recalled facts and events, such as all the things we learn about the world that surrounds us. Explicit memories are often formed intentionally, by rehearsing already gained knowledge. It’s further subdivided into:
- Semantic memory
- Episodic memory
Semantic Memory
The gathered knowledge of general facts and concepts about the external world that surrounds us is referred to as a semantic memory, like what is a banana, the meaning of a particular word, or which city is the capital of Portugal.
Episodic Memory
Episodic memory denotes the facts from our personal past, i.e. our personal world, which are stored just like episodes of our levis in the long term memory.
These are the memories of our personal experiences, such as graduation day, the memory of the color of the feathers of our first pet-parrot, how our first day at school went, etc.
Fun Facts
Did you know?
- The hippocampus, cerebellum, and amygdala are the parts of the brain in charge of encoding information in order to be learned, i.e. stored in several different types of memory. They receive it through the neuronal connections from the primary sensory areas of the cortex, after which this information is translated and related to similar information that has previously been stored.
- Infantile amnesia refers to our childhood period (from birth to around 2-3 years of age), when our declarative memory stabilizes. We are unable to retrieve any of the information stored in the earliest days of our lives, due to the inability of very young children to create strong memories about events that would later be stored in the memory.
- Our ability to remember things is the strongest during our 20’s. After we reach our ’50s and ’60s, the cognitive functions of the brain start to show signs of fatigue, which makes the retrieving of the stored information in our memory much more difficult.
- Neurogenesis is a process in which the stem cells of the adult brain create new neurons. With aging, these cells lose their ability for regeneration, thus contributing to our deteriorating memory when we reach a mature age.
- Our prospective memory, i.e. the ability to start remembering to do things at a future point in time, begins to develop around 4-7 years of age.
- Bilingualism contributes to the wellbeing of our brain, because due to the neuroplasticity of the brain, the gray matter increases its density. In this way, our capacity for learning also expands.
- The change in both the neural pathways and synapses they make occurs as a result of various factors. Namely, the brain removes the synapses which no longer serve a quality function in order to strengthen the important ones. This process is called the neuroplasticity of the brain.
- The stronger the emotional content of a particular memory is, the longer it will remain stored in the brain. On the other hand, while stressful events have a negative impact on memories, positive events are more likely to reinforce our memory of them.
- When the information is split into a few smaller pieces in order to aid understanding and make reading easier and faster, it’s stored in the short term memory. When these pieces of information are frequently recalled, they are transferred into the long term memory.
- There is no specific area in the cerebral cortex of the brain that stores memory. There are several brain structures that perform this function.
Moreover, it would be dangerous if all memories were stored in only one area of the brain. For instance, if that brain area suffers damage, all our memories would be lost forever.