The structure of semantic memory has often been investigated by using studies that manipulate the semantic relatedness of stimulus items, and use facilitation and inhibition effects to make inferences about semantic memory's structure. In the current work, we present two experiments using the visual world paradigm where we systematically manipulate the semantic relatedness of the distractor item when a participant is asked to look at (Experiment 1) or click on (Experiment 2) a target image. Both experiments yielded consistent patterns of results such that there was more competition from the distractor image the more semantically related it was to the target. The graded effects observed provide additional evidence for a graded and feature-based representational structure in semantic memory.

This study investigates the interaction between semantic relatedness and goals or task on memory retrieval. We used varied tasks and concepts to explore how task influences how different kinds of semantic relatedness influences semantic processing. Our findings reveal a task-dependent interaction with semantic relatedness. Specifically, in similarity judgement tasks (experiments 1a and 1b), participants' ratings closely aligned with taxonomic relatedness, influenced by abstract visual and linguistic similarity dimensions. In discrimination tasks (experiments 2a and 2b), where participants distinguished a target from a semantically related distractor, visual characteristics explained a greater amount of variance. These results suggest semantic memory representations are dynamic and task-dependent, supporting theories of a distributed semantic memory system.