What we may not realize as much are the times when our memory works splendors. Just imagine – we can remember the time when we fell down and scraped our knee on concrete at seven. We can remember that World War I happened between 1914 and 1918, and, perhaps less impressively, that the current president of the United States is Barack Obama. Although these seem like diminutive abilities, brain-injured patients with amnesia show us that memory is extraordinary and that memory deficits have a great impact on our ability to function in daily life.
One of the divisions of long-term memory, our permanent store of facts and knowledge, is declarative memory. Declarative memory consists of semantic and episodic memory. Semantic memory consists of general knowledge, like “George Washington was the first president of the United States.” On the other hand, episodic memory encompasses the events we have experienced at a specified time and place. Semantic and episodic memory are important concepts to understand when talking about brain-injured patients because, depending on the injury, semantic memory could be affected, but not episodic memory, and vice versa.