Did You Know?

It was in 1972 that Dr. Endel Tulving, an Estonian Canadian experimental psychologist, coined the term 'episodic memory' to denote the memory of a personal experience or specific event from a particular time and place, while contrasting it to the semantic memory, which is the general store of knowledge a person has.

The medial temporal lobe of the brain plays a vital role in the processes involving episodic and semantic memory. Though semantic information might be derived from several events in one's life, there are certain differences between the episodic and semantic memory. These include: ➠ The major difference between the two is that the semantic memory just involves the knowledge of facts and concepts that we have acquired, whereas the episodic memory is a recollection of a specific event experienced by a person. Semantic memory involves knowing, whereas episodic memory involves remembering. While remembrance always implies knowledge, knowledge does not imply remembrance. Thus, two persons who are a part of a particular event might not have the same episodic memory. For example, two individuals who start working in an organization on the same day will not have the same episodic memory, as their personal experience on their first day at work is likely to be different. ➠ Autonoetic awareness is another characteristic feature of the episodic memory. When a person remembers an event autonoetically, he/she has the awareness of self in a subjective time while recollecting an event from the past. On the other hand, in case of a semantic memory, experiencing the learning episode of a concept or fact is not necessary. For instance, we all know how to add, and wouldn't need to recall the time and the teacher who taught us how to add. ➠ While episodic memory involves remembering a specific event, the semantic memory is associated with knowing or the knowledge about factual information. Mental time travel to an earlier time is the characteristic feature of an episodic memory. The individual would mentally travel back in time to remember and reconstruct the event that occurred at a certain time in the course of his/her life. Usually, these are major or minor events or episodes that hold a place of importance in our lives, and we are likely to recall other details such as the time, date, location, people who were a part of that event, sensory information (emotional aspect), etc. The characteristic features of such memories include visual imagery, feelings of familiarity, narrative structure, retrieval of semantic information, etc. On the other hand, semantic memory is the knowledge of facts, concepts, etc., and is usually required for the completion of the tasks one is performing at the present. Its retrieval doesn't require thinking back in time about a past event.

There are certain formative events or experiences that most people tend to remember. One tends to remember the time, place, context, and other important details of such events. One can mentally reconstruct the event by going back in time. It must be noted that the event can be major or minor. A few examples of this type of memory are given below: ➠ Your last vacation ➠ Your first date ➠ Milestone birthday celebrations ➠ When you received an award ➠ Your wedding ➠ Wedding of a loved one ➠ Your last meeting with your boss ➠ Your first day at work ➠ Your first airplane trip ➠ The first time you drove a car ➠ What you had for dinner last night ➠ The last movie you watched with your friends ➠ High school graduation Memories of such events in life are processed in the hippocampus and consolidated in the neocortex. We can often recall such events, unless there's any damage to the hippocampus. Thus, our autobiographical memories are episodic initially. Autobiographic memory is basically a memory system that represents one's personal history, which in turn is based on the recollection of episodes from one's personal life, as well as the semantic information.

Some of the events that are recorded in one's episodic memory can also be responsible for certain types of behavior. For instance, if a person was bitten by a dog during childhood, the recollection of that event might even cause that person to develop a fear of dogs. Certain events in life are packed with emotions, and these might be encoded as a vivid memory, and remembered in such a manner. Often, psychologists and therapists are able to gather important information from the episodic memory of the patient. In several cases, the patient's mental state is deeply affected by a particular event from the past. Thus, gathering information about such an event can help them properly assess the patient's condition, as well as determine the suitable treatment. A psychologist might look to memories from childhood or recent events for understanding a person's psyche or current mental state/behavior. However, the process of retrieval can be a daunting task, as factors such as manipulation of cues, prior retrieval, and the patient's imagination can impact or even modify what is retrieved from memory.