6 ideas
Episodic memory stores personally experienced events tagged with when and where they happened to the rememberer. Semantic memory stores context-free knowledge of facts, words, and concepts that the person can use without knowing when or how it was learned. The two differ in what they hold, how they are organized, and how retrieval feels, which is why they are treated as separate systems rather than one store.
A retrieval cue works only if the information it carries was encoded together with the target at the time of the original experience. What gets stored is the event as the person perceived and interpreted it in that context, not the nominal stimulus. A cue that is strongly associated with the target in general can therefore fail, while a weakly associated cue that was present at study can succeed.
Ecphory is the process in which a retrieval cue interacts with a stored memory trace to produce remembered information. The output is jointly determined by trace and cue, so neither alone fixes what is remembered. The same trace can therefore yield different recollections under different cues, and remembering is a construction at retrieval rather than a readout of the trace.
Subjects studied target words paired with weak cues, then took a recognition test in which they often failed to pick those targets from a list. When they were later given the original study cues, they could recall many of the same words they had just failed to recognize. This reversed the assumption that recognition is always easier than recall and showed that retrieval depends on cue-trace compatibility, not simply on how strong the trace is.
The model breaks an episode of remembering into elements: the original event, encoding into an engram, recoding over time, a retrieval cue, ecphory, the resulting ecphoric information, and conversion into recollective experience or overt behavior. Each element can be varied and studied independently, so a memory failure can be traced to encoding, storage, cue quality, or conversion instead of being put down vaguely to forgetting.
Tulving holds that the defining product of episodic retrieval is a subjective experience of re-living a past event, a form of mental time travel. It is not just correct output on a test. To enter this state a person must adopt a retrieval mode, deliberately treating a cue as a prompt about their own past. Measuring memory only by accuracy misses the phenomenal awareness that marks something as remembered rather than merely known.