Episodic memories are memories of events in which we participated. They can be of something as monumental and unforgettable as one’s own wedding or college graduation, or they can be as simple and forgettable as what one ate for dinner last night. In summary, they are an autobiographical recollection of past experiences that occurred at any given time or place and it is believed that they are stored in a temporal manner. Episodic memories are associated with a point in time and whether or not we can recall it.
The medial temporal lobe is where episodic memories are formed and stored (particularly in the hippocampus), but it is also believed that the prefrontal cortex is important in this procedure, as well, due to experiments that have shown that when it is damaged, episodic memories have a harder time being created. Researchers debate how long memories are stored in the hippocampus. Some believe that they are forever there and lay dormant when not remembered, while others believe that they are only temporarily there and are replaced as new memories are made with only the significant memories being saved. Alzheimer’s Disease, which erodes away memories, tends to damage the hippocampus significantly before damaging other brain areas. This disease, which killed my own grandfather, deteriorates all the memories and thus, all the sanity of a person, leaving them only with a shell of their former self before their brain finally shuts down from all the corrosion.
Contrarily, semantic memories are the opposite yet they are similar. They typically are memories we have in regards to the world around us and general facts about it. Examples can include what the capital of France is, or what the inside of an atom looks like, or what color the sky is. Semantic memories are not usually of a personal nature, unless it was something like one’s own hair color, and do not require that we mentally “travel back in time” to recall them happening to us, like we would with a high school graduation or a wedding. Semantic memories, like Episodic memories are LTM. Because of this, some question the necessity to even distinguish the two of them.
In my own life, I can identify many episodic memories such as my high school graduation, when I met my surrogate parents (I like to think of them as my parents because my real parents and I don’t get along at all), when I first discovered my most favorite music group, and when I realized that I wanted to earn a double doctorate in Chemistry and Psychology. I find that with episodic memories, I can remember them eloquently and without difficulty, whereas with semantic memories, depending on what it is, I can have trouble memorizing them. For example, I absolutely hate math. I would study and study for a math test for countless hours and still not remember any of it when the test came. Both episodic and semantic memories are in our daily lives everyday yet we, as people, fail to realize or understand what they are and how much of a vital part of our existence they are.
Elbich, D. (2016) Lesson 6: Episodic Memories. Retrieved from Lecture Notes Online Web site.
Elbich, D. (2016) Lesson 6: Semantic Memories. Retrieved from Lecture Notes Online Web site.