Natural units of representation interact during sentence comprehension

Subjects read aloud the verb IS and ARE that was projected to interrupt a spoken sentence: immediately preceding the projected word, the sentence contianed a "verb" + ing noun" sequence, which was either a gerund ("raking leaves"), an adjectival phrase ("diving submarines") or ambiguous ("growing flowers"). The experiment investigated the effect on word-reading time of various independent variables in the preceding context clause that biased the subject to expect either a gerund or adjectival construction. The operational measure of the effectiveness of a context was the difference in reading time between a word consistent with the bias and a word inconsistent with the bias. The stronger effects occurred when the "verb + ing noun" phrase was ambiguous and (1) the plural/singular dimension in the preceding context clause was morphologically explicit, (2) the context clause was introduced by THOUGH (as opposed to IF, or being a main clause), (3) there was an explicit form of BE in the context clause, (4) the biased interpretation from the context clause was the gerund. These effects and others support a structurally differentiated model of comprehension in which listeners link representations at distinct levels of representation expressed in the units that are most natural at that level (e.g., propositions at the semantic level, words and word-groupings at the syntactic level).