Clauses and the semantic representation of words

When a sentence with more than one clause is processed, words of the first clause become less available for recall or recognition once the clause boundary has been passed. One common interpretation of this observation is that the representation of a given word shifts from a predominantly surface form (e.g., phonological or lexical) to a semantic form, after the clause boundary. Two experiments that test that interpretation are reported. In the first experiment, two-clause spoken sentences were followed by spoken word or picture probes. Pictures were intended to provide a fast semantic match to probed words, but a slow surface match. Although response times exhibited a robust main effect of the clause position of the probe, no interaction with probe type was found. Similar results were obtained in a second experiment that compared pictures with written word probes. The faster response to picture than to word probes in the second experiment indicates that subjects did not covertly name the picture, but made a semantic match (as intended). These observations suggest the following reinterpretation of earlier sentence memory experiments: Words in the most recent clause of a sentence are more available than words in an earlier clause because their semantic representations are more active, not because their surface representations are more active.