What Part of the Brain Controls Memory?

There are several parts of the brain where memories are stored depending on the type of memories:

Explicit Memories are long-term memories that are stored in the following brain structures:

• Hippocampus
• Neocortex
• Amygdala

Implicit Memories are long-term memories that are stored in the following brain structures:

• Basal Ganglia
• Cerebellum

Working Memory and short-term memory are stored in the following brain structure:

• Prefrontal Cortex

1. What Is Memory?

Memory is the faculty of processing, storing, and remembering experiences and knowledge. It is what makes us and what makes our identity.

Memories are processed, stored, and reactivated in specific neurons that interact with each other through synapses which are known as synaptic plasticity.

Memories are made stronger or weaker depending on dynamic interactions between these groups of specialized neurons.

Memory is divided into short-term memory or working memory and long-term memory which includes explicit and implicit memories.

2. What Does It Mean to Have an Explicit Memory?

Explicit memories are conscious memories that recall events that happen to us (episodic memories) or that recall general knowledge of the world (semantic memories).

They are formed and stored in a specific group of neurons found in the hippocampus, neocortex, and amygdala.

2.1. What Does the Hippocampus Do for Memory?

The hippocampus is the structure of the brain where episodic memories are formed and stored. It is situated in the temporal lobe of the brain.

In addition to its role in long-term memory, the hippocampus is also involved in learning, flexible and goal-oriented behavior, navigation, and spatial orientation.

The hippocampus is also one of the two areas of the adult brain where there is still the production of new neurons (hippocampal neurons) due to the presence of neural stem cells.

2.2. What Does the Neocortex Do for Memory?

The neocortex serves as a storage area for temporary memories provided by the hippocampus and that are stored in a form of semantic memories.

It is the largest part of the cerebral cortex and is also involved in sensory perception (perception of outside stimuli), spatial reasoning, language, and the planning, control, and execution of voluntary movement.

2.3. What Does the Amygdala Do for Memory?

The amygdala is an almond-shaped structure of the brain’s temporal lobe involved in the formation and storage of emotional and fear-associated memories.

In addition to its role in memory, the amygdala is also involved in emotional responses (e.g., fear and anxiety) and decision-making in response to external stimuli.

3. What is Implicit Memory?

Implicit memories are unconscious or automatic memories that do not require conscious or voluntary recall to influence our behavior.

Implicit memories are divided into priming memories and procedural memories:

• Priming Memories

A priming memory is an unconscious improvement or change in dealing with a stimulus because of a previous experience with the same or a related stimulus [2].

• Procedural Memories

Procedural memory is associated with performing tasks without being consciously aware of doing them. An example is the capacity of riding a bike even if we did not cycle for a long period.

Implicit memories are formed and stored in a specific group of neurons found in the basal ganglia and cerebellum.

3.1. What Does Basal Ganglia Do for Memory?

Basal ganglia are structures resting deep within the brain and are involved in the storage of procedural memories [3].

Basal ganglia are also involved in many functions of the brain, including cognition, emotion, procedural learning, conditional learning, habit learning, and control of voluntary motor movements.

3.2. What Does the Cerebellum Do for Memory?

The cerebellum is situated at the back of the brain and is involved in procedural memory but also in motor learning and classical conditioning.

In addition, the cerebellum is involved in controlling the body balance, coordination, movement, and motor skills.

4. What Is Working Memory?

Working memory is a temporary storage of a small amount of information ready for immediate mental use [4].

5. What Is Short-Term Memory?

Working memory is a temporary storage of a small amount of information without manipulation of the information stored [5].

Theoretical concepts differentiate between working memory and short-term memory as short-term memory is suggested to refer to the maintenance while working memory involves a combination of maintenance and manipulation of information.

However, correlational studies have not been able to separate between working memory and short-term memory [5].

Working memory and short-term memory are mediated by the prefrontal cortex.

4.1. What Does the Prefrontal Cortex Do for Memory?

The prefrontal cortex is situated at the front part of the frontal lobe and is involved in the storage of a small amount of information.

In addition, the prefrontal cortex is involved in many functions of the brain, including executive processes (differentiating between conflicting thoughts), information processing, attention, judgment, behavioral organization, and certain aspects of language and speech [6].

5. What Are the Types of Memory Loss?

Memory loss is known as amnesia which can be caused by head or emotional trauma, Alzheimer’s disease, brain tumor, alcoholism, seizures, encephalitis, or stroke [7]. There are several types of amnesia:

• Retrograde Amnesia
• Anterograde Amnesia
• Post-Traumatic Amnesia
• Transient Global Amnesia
• Dissociative Amnesia
• Infantile Amnesia

5.1. What Is Retrograde Amnesia?

Retrograde amnesia is the incapacity to recall events or information from the past.

5.2. What Is Anterograde Amnesia?

Anterograde amnesia is the incapacity to recall new events or information following an amnesia incident.

5.3. What Is Post-Traumatic Amnesia?

Post-traumatic amnesia is a state of confusion associated with to incapacity to recall new events or information immediately after a traumatic incident.

5.4. What Is Transient Global Amnesia?

Transient global amnesia is a temporary sudden and total loss of short-term memory.

5.4. What Is Dissociative Amnesia?

Dissociative amnesia is the incapacity to recall personal information following trauma or stress.

5.5. What Is Infantile Amnesia?

Infantile amnesia is the incapacity to recall events or information from childhood.

Conclusion

Memory is a complex process that involves several parts of the brain that process, store, and reactivate conscious and unconscious information from the past and when we need them. Without memories, it is impossible to know who we are, what we are doing, and what we are planning to do.