Lion-Tiger-Stripes: Delimiting the Semantic Association Effect on Working Memory With Mediated Association.

Semantic relatedness of items improves working memory performance. We targeted one type of semantic relatedness, semantic association. The beneficial effect of association is often explained by the spreading-activation process: Encoding/maintaining an item would activate its associated item. Nevertheless, as associated words can be similar to each other (e.g. similarity based on the Latent Semantic Analysis), other processes, rather than spreading activation, may also explain the association effect. To target spreading activation selectively, a novel hypothesis unique to this process was tested. Specifically, we tested the effect of mediated or two-step association, which the spreading-activation theory assumes (e.g. lion → tiger → stripes). To examine the mediated association effect, Experiments 1, 2A, and 2B presented word pairs with indirect association (e.g. "lion" and "stripes") without mediators (e.g. "tiger"). Only one of the three experiments provided moderate evidence for a beneficial effect of mediated association. Additionally, cross-experiment and item-level analyses did not support the mediated association effect. By contrast, Experiments 3 and 4 presented word pairs with direct association (e.g. "tiger" and "stripes") and demonstrated extreme evidence for a beneficial effect of direct association. The negligible effect of mediated association would aid in delimiting the scope of association's influence on working memory.