I recently came to the frightening realization that I don’t remember the details of films I watched more than a few months ago. When people describe scenes in detail, I might have a vague sense of recognition, but I can’t visualize the scene, who was in it, what their names were or at what stage of the plot it happened.
The most worrying part is that my mother has the same problem. Oh no… is this a hereditary limitation that I should not attempt to fight? I’m honestly unsure, so I decided to start digging.
Episodic vs. semantic memory
Apparently, people can differ in how well they recall specific episodes in detail versus how well they build high-level syntheses: connecting ideas and concepts, and responding emotionally to stories. That can happen at a meta-level, without remembering details like names or timelines. It is more of a prolonged emotional response.
According to one source, “Episodic memories are far more vulnerable to forgetting and distortion than semantic memories, which tend to be more durable once consolidated” (Psychology Notes HQ). That seems to make sense. The classic picture of Alzheimer’s is of someone forgetting what they did recently, in an autobiographical way, while often keeping a good grasp of places, political affiliations or even events from long ago.
Ultimately I’m still a bit disappointed that I can’t have an in-depth conversation with friends about that one movie we watched together a year ago. But I’m comforted to know that my semantic memory is doing great and that I can connect concepts to one another.
The bigger picture
This also made me curious about the wider theory of memory types. Episodic and semantic memory are both explicit (conscious) memory. There are also implicit, unconscious types, covering motor skills, recognition from prior exposure, and learned associations and reflexes.
I reproduced the diagram from the Psychology Notes HQ article as a table:
| Long-term memory (lasting days to decades) | Type | What it is | Examples |
|---|---|---|---|
| Explicit (declarative, consciously recalled) | Episodic | Personal events and experiences, with context: when, where, how you felt | Your first day of college; what you had for breakfast |
| Explicit (declarative, consciously recalled) | Semantic | Facts, concepts and language, with no personal context attached | Paris is the capital of France; dogs are mammals |
| Implicit (non-declarative, unconscious) | Procedural | Motor skills and habits | Riding a bike; typing |
| Implicit (non-declarative, unconscious) | Priming | Prior exposure speeds up recognition | Word completion |
| Implicit (non-declarative, unconscious) | Conditioning | Learned associations and reflexes | Pavlov’s dogs |
Diagram source: © The Psychology Notes Headquarters, psychologynoteshq.com.