Why the leash constrains the dog: the impact of semantic associations on sentence production.

The production of language is one of the most complex and amazing skills in humans. Increasing evidence demonstrated that associative relations (e.g., car - garage) play an important role during concept formation but during speech production the effects and processing of associations are highly debated. Hence, the present study investigated the impact of associations and different SOAs on the production of sentences (Experiment 1) and on naming objects (Experiment 2). In an adapted version of the picture-word interference task, participants were asked to name two pictures using a standardized sentence (e.g., "The car is to the left of the trousers"). Thereby, a simultaneous (SOA is 0 ms) or slightly preceding (SOA is -150 ms) auditory or visual distractor had to be ignored. Distractors were related to the first noun (for example: "The car is to the left to the trousers", distractor: "garage") or to the second noun (distractor: "belt") or unrelated to both nouns (distractor: "bottle") of the sentence. At simultaneous presentation, visual and auditory distractors related to the first noun of the sentence prolonged naming responses (i.e., interference). For slightly preceding distractors, only visual presentation induced interference for the first noun of the sentence. During no condition, longer naming responses were found for the second noun of the sentence. These effects suggest that associatively related concepts are active during speech production and can be competitors, i.e., they lead to semantic interference. In Experiment 2, subjects had to name an object (e.g., car) while ignoring a visually presented distractor (e.g., motor). The stimulus set was the same as in Experiment 1. The results showed a facilitation effect if the distractor and the target were associatively related. Overall, the current results provide new insight in the models of speech production: while during single word production, associations facilitate naming, they interfere during sentence production. Hence, associations have an important influence on producing speech but the impact is varied by the context, i.e., single word or sentential.