The Interplay of Long-Term Memory and Working Memory: When Does Object-Color Prior Knowledge Affect Color Visual Working Memory?

Elaboration enriches newly encoded information by connecting it to prior knowledge. Here, we tested if prior knowledge about object-color associations improves visual working memory (VWM) for colors. A sequence of four colored objects was presented in four screen locations for a continuous color reproduction test. Object-color associations were either congruent with prior knowledge (e.g., red tomato) or incongruent (e.g., blue tomato). In Experiments 1 and 2, congruency had no effect on memory irrespective of memoranda format (images or words), encoding time (1,500 vs. 4,500 ms), and an instruction to elaborate. In Experiment 3, the object was also tested with a three-alternative forced-choice before or after probing color memory. We also included neutral objects (no color association) and abstract shapes and tested VWM and episodic memory. Congruent items were remembered better than in all other conditions, which did not systematically differ. In Experiment 4, we assessed the congruency effect when only color or both color and object were tested. Congruent objects were remembered better only when both features were tested. Hence, prior knowledge boosts VWM only when this knowledge is relevant at test. Our results suggest that retrieval manipulations can be critical for promoting the use of long-term memory knowledge.