How implicitly activated and explicitly acquired knowledge contribute to the effectiveness of retrieval cues.

The extralist cued recall task simulates everyday reminding because a memory is encoded on the fly and retrieved later by an unexpected cue. Target words are studied individually, and recall is cued by associatively related words having preexisting forward links to them. In Experiments 1 and 2, forward cue-to-target and backward target-to-cue strengths were varied over an extended range in order to determine how these two sources of strength are related and which source has a greater effect. Forward and backward strengths had additive effects on recall, with forward strength having a consistently larger effect. The PIER2 model accurately predicted these findings, but a plausible generation-recognition version of the model, called PIER.GR, could not. In Experiment 3, forward and backward strengths, level of processing, and study time were varied in order to determine how preexisting lexical knowledge is related to knowledge acquired during the study episode. The main finding indicates that preexisting knowledge and episodic knowledge have additive effects on extralist cued recall. PIER2 can explain these findings because it assumes that these sources of strength contribute independently to recall, whereas the eSAM model cannot explain the findings because it assumes that the sources of strength are multiplicatively related.