We all have a lot of dear or unpleasant memories which we nurture since the earliest ages of our childhood days. Also, we are able to describe most of them in detail: when did they happen, how did they happen, why did they happen, where did they happen.
Special days, events, and feelings are triggered by a specific event in memory. Like TV episodes, they help us recall information about who, when, where, or why something happened. These types of memories which have been stored in our brain are all in the category of episodic memory.
Later in life, episodic memory influences our decisions by encouraging them or preventing us in some future endeavor.
What Is Episodic Memory?
Episodic memory is the capacity to re-experience specific personal experiences and events by recalling the long-term memory we have of them. It’s a conscious recollection of a personal experience related to a specific place, time, event, feeling, or location.
In short, episodic memory stores episodes of our lives, such as our best friend’s graduation party, our first day at school, our first kiss, the best summer holiday we’ve had, etc. It’s a memory of our everyday lives, the most personal type of memory we refer to when we speak of memories.
What Part of the Brain is Associated With Episodic Memory?
Memory is merely an electric impulse. It carries the signal of the information received from the sensory stimuli to the hippocampus, as the primary brain area where the memory is formed.
This brain structure is responsible for both the recognition of place and the merging of both short-term and long-term memories. It’s a process of transformation of recently memorized experiences into long-term memories by strengthening the synapses between the neurons.
The hippocampus transmits the information from the temporal lobe of the brain (where the hippocampus is found) to the regions of the cerebral cortex which gives meaning to the information by conducting complex neurological processes and connecting them with other related memories.
How Is Episodic Memory Created in the Brain?
Being one of the major cognitive processes of the human brain, episodic memory is a unique system of the cerebral cortex responsible for long-term storage of dedicated information intended for future reference.
Hence, the formation of episodic memory is a complex process involving three main stages:
- Encoding
- Consolidation
- Recollection
How Is Episodic Memory Encoded?
The first stage of the formation of episodic memory is the encoding of information. It’s the process of receiving data via the sensory stimuli, during which concentration is one of the most crucial features for the creation of long-term memory.
Namely, if we don’t pay enough attention to an event, we will not have sufficient data (or details) to be encoded in the memory. In such a case, it becomes less likely that we will remember the information or the event.
How Is Episodic Memory Consolidated?
The consolidation of memory is the second stage in forming the episodic memory. During this process, the brain structures and neural networks strengthen, stabilize, and store the traces of memorized information received via the sensory stimuli. This is done so that they can be easily retrieved at a future point in time.
This complex process, which occurs during a period of time encompassing days or weeks, activates the neural pathways from the hippocampus to the cerebral cortex in order to aid the consolidation of episodic memory.
How Is Episodic Memory Recollected?
A recollection of episodic memory is nothing but a conscious retrieval of the information gained from the sensory stimuli stored in the brain. Several cues, such as emotions, smell, sound, visual representations, and semantic knowledge, can aid the retrieval of episodic memory.
However, if we were distracted during the process of encoding information, it would be much more difficult to recollect all details of the event stored in our long-term memory, because the information could not be entirely encoded in the first place.
What Is Episodic Learning?
Episodic learning refers to remembering the sequences of the event we have experienced, which are stored in the episodic memory as our personal account of an event, place, or feeling. It’s a change in our behavior that’s triggered by something we have witnessed or experienced.
In short, it’s the process of storing our personal experiences in episodic memory by making logical ‘episodes’ of a unique personal occurrence, synchronizing elements such as feelings, place, sounds, time, etc.
Which Medical Conditions Can Affect Episodic Memory?
Many medical conditions and neurological diseases can negatively affect episodic memory by damaging the neural memory networks as well as the structures of the cerebral cortex which are dedicated to this type of memory:
- Alzheimer’s disease – A disease that causes a slow and gradual decline in episodic memory in its progressed stage, which eventually results in amnesia.
- Hashimoto’s encephalopathy – A neurological disorder associated with slower mental speed and memory loss.
- Lewy body dementia – An auto-immune thyroid disease. It’s characterized by a progressive decline in the mental abilities of the affected individual due to abnormal deposits of protein in the brain, which can lead to loss of memory.
- Delirium – A state of severe confusion and sudden change in the cognitive functions of the affected individual, which can result in reduced memory.
- Subarachnoid hemorrhage – A severe and life-threatening medical condition, which can lead to problems with memory.
- Hydrocephalus – A medical condition of liquid accumulation in the brain that can cause damage to the brain. This, in turn, can lead to loss of memory.
- Vitamin B1 deficiency – Lack of sufficient accumulation of Vitamin B can trigger the Wernicke-Korsakoff syndrome, and lead to memory loss.
Since episodic memory is closely related to the degree of attention during the process of gaining information from the sensory stimuli, the conditions that interfere with our ability to pay attention can also affect it negatively.
To Sum Up
Memories help us get to know the world that surrounds us by turning insights into events, as well as forming our reactions based upon our previous experiences.
Episodic memory is the ability of the brain to collect, integrate, and store specific details of an event or feeling. After the complex process (which begins in the hippocampus) is completed, dedicated brain structures create ‘episodes’ of our personal past happenings.
These recollections can remind us of a specific occurrence, occasion, emotion, location, time, etc. Since episodic memory refers to information gained from highly personal experiences, it’s impossible for the other people involved in the same experience to share an identical memory of it.
Fun Facts
Did you know?
- Episodic memory is developed only in humans.
- The encoding of information can be strengthened by means of association. Namely, the more connections we make with the encoding information by associating it to similar data, the more likely we will remember it sooner and better.
- When the trace of memory is consolidated, it can be stored infinitely in the brain for retrieval at a future point in time.
- Episodic memory ‘allows’ the individual to remember its own, personal thoughts and feelings regarding an event, rather than just facts.
- The episodic memory of an individual differs from another person’s recollection of the same experience because it’s influenced by the individual’s personal past happenings.
- This type of memory incorporates three main elements – personal thoughts/feelings, awareness of the world around us, and subjective time.
- The information stored in episodic memory is very sensitive to the structure and context of the individual’s experience.
- The retrieval of episodic memory requires consciousness. It is not possible to unconsciously recollect any ‘episode’ of our personal life.
- Memories start to form as early as 2 years of age. This is why no one can remember being born.
- According to the decaying theory, memories can be forgotten if we don’t recollect them often.