Episodic vs. Semantic Memory

Differences/Similarities Between Episodic and Semantic Memory

Episodic memory contains memories of personally experienced events and the context in which they occurred. It makes possible mental time travel through subjective time from the present to the past, thus allowing one to re-experience one’s own previous experiences.

Distinguishing features of episodic memory are that it allows us to access information concerning where and when personal events in our lives occurred.

Semantic memory, on the other hand, is an individual’s store of knowledge about the world. The content of semantic memory is abstracted from actual experience and is therefore said to be conceptual, that is, generalized and without reference to any specific experience.

Notwithstanding the significant distinction, there are similarities between episodic and semantic memory.

Suppose you remember meeting your friend recently at a coffee shop. That clearly involves episodic memory because you are remembering an event at a given time in a given place. However, semantic memory is also involved — some of what you remember depends on your general knowledge about coffee shops, what coffee tastes like and so on.

Both episodic and semantic memory may involve facts, even the same facts, but their significance is different. While hiking in the mountains, you could be attacked by a mountain lion.

When you recall facts related to that experience (the color of the animal, the name of the park where the attack occurred, the number of stitches you received), you are recalling things that you personally experienced, and you are drawing on episodic memories.

I may read a newspaper account of your experience. When I recall the color of the animal, the name of the park where the attack occurred, and the number of stitches you received, I am drawing on semantic memory.

The similarity between these memories shows that despite the distinctive differences between episodic and semantic memory, they are highly interactive and can be seen as part of the declarative memory system Opens in new window.

Some information can be stored in both episodic and semantic memory. It is certainly possible to store in the semantic memory autobiographical details such as the number of siblings one has without having to access and remember whole scenarios about oneself in relation to the siblings and past experiences.

Thus, we can build up a semantic knowledge about an object through our past experiences from which we have abstracted and generalized. However, when we encounter an object that is personally meaningful, we initially apply generalized and abstracted knowledge to the object at the recognition stage.

Because much of the same kind of information can be stored in episodic Opens in new window and semantic memory Opens in new window, the difference between them may seem arbitrary, even contrieved. But defenders of the distinction argue that whereas both deal with facts, episodic memory deals with facts that have a personal connection for the individual.

Your memory of the mountain lion attack is of a personal experience, for example, whereas my memory is of facts that hold no personal connection to me.

There is also a temporary distinction between these two kinds of memory.

For you, the attack fits in a personal timeline—you probably remember how old you were, what year the attack took place, the season, that you were just about to go off to college, that your entry to college was delayed for a year while you recuperated, that you decided to change your major from wildlife biology to urban planning.

For me, the comparable memories (in the unlikely event that I recalled them) would be the name of the newspaper that carried the story, where I was when I read it , why I was in that particular place, and the like.