The semantic content of modifiers causes retrieval interference during language comprehension: Evidence for modifiers as floating information in memory space

Past research has shown that modifications facilitate the subsequent retrieval of associated words during language comprehension. This modification-induced retrieval benefit has been attributed to the formation of more distinct memory representations for modified words due to their enhanced semantic richness. In this study, we investigated if the semantic content of modifiers as well as age-related cognitive decline can affect retrieval interference for modified words. Younger (N=70) and older (N=61) participants read sentences containing a target word (e.g., butterfly) and a competitor (e.g., passenger). The target words were modified either by adjectives that exclusively fit the target (e.g., colorful and shimmering), or by inclusive adjectives that semantically fit both the target word and the competitor (e.g., calm and resting). We measured self-paced reading times on a subsequent verb that triggered the target’s retrieval. Critically, reading times on the retrieval site increased as the semantic similarity between the modifiers and the competitor increased (i.e., as the modifiers fit the target words less strongly), suggesting retrieval interference as a function of modifier content. Because the modifiers were always syntactically attached to the target, an interesting implication of these results is that modifiers are not strongly bound to the associated word in memory. Instead, modifying information seem to be “floating” in memory space, available to attach to multiple words, thereby causing interference during the retrieval of a target memory item.