Sentence production and working memory

Previous research has shown that subjects can make up sentences faster from related noun pairs than from unrelated pairs. Two experiments tested the proposal that for the related pairs a subject simply has to access stored information but must make up an appropriate relation for unrelated pairs. In both studies the subjects were asked on some trials to remember a digit preload while they made up their sentences. Contrary to an initial prediction, the latencies were faster rather than slower with a preload. Furthermore, a surprise recall test at the end of Experiment 2 showed that there was no difference in the recall of related and unrelated pairs. The results were interpreted as evidence that semantic work was necessary for both types of noun pairs, and that the subjects did less semantic work with a digit preload. This interpretation was further supported by the finding that with the preload the subjects produced a narrower range of semantic relations between the noun pairs.