3.2.1 Episodic versus Semantic Memory

In proposing a distinction between episodic and semantic memory, Tulving argued for the utility of distinguishing between the traces of personal experience, on one hand, and general knowledge, on the other. Specifically, episodic memory refers to storage and retrieval of personally dated, autobiographical experiences. Recall of childhood experiences, recollection of the details of a conversation with a friend, and remembering what you had for breakfast all would fall within the realm of episodic memory. The critical feature of episodic memory is the existence of a "personal tag", and the basis for retrieval is an association with a particular time or place. Obviously, a great deal of what we must recall in order to function effectively in our daily lives is of an episodic nature.

Semantic memory, in contrast, refers to memory of general concepts and principles and their associations. Unlike episodic memory, semantic memory is not linked to a particular time and place. In our semantic, memory is such information as the fact that lemons are yellow and that computers contain chips. Semantic memory contains the organized knowledge we have about words and concepts and how they are associated. For instance, a subject area such as Egyptian literature or American history represents a vast body of semantic information that we (as we become more expert in the area) encode, organize, and have available for retrieval. Recalling word meanings, geographic locations, and chemical formulas similarly requires searches of semantic memory.

Although the psychological validity of the episodic‑semantic distinction has been criticized, it continues to be useful in helping us think about the different types of information we must remember. On one hand, the episodic aspect of our memories must function well enough for us to locate ourselves in time and space and have a reasonably accurate record of our experiences. At the same time, we have to have available a general knowledge base in order to think and reason effectively. Of course, the episodic‑semantic distinction does not presuppose two physically separate systems in the brain, but rather is a conceptual distinction useful to researchers and practitioners.