Does structural complexity necessarily imply processing difficulty?

Our goal is to establish a link between the time needed to plan a sentence containing an embedded clause and the structure of this sentence. Contrary to a traditional monolithic conception of subordination, three types of embeddings were considered, depending on their degree of syntactic integration: subcategorized, modifier and pseudo-embedded clauses. We hypothesized that in the case of subcategorization, fewer pauses should occur between the matrix and the subordinate clause since the latter is required by the lexical properties of verbs. By contrast, pseudo-embedded clauses are the less integrated. Hence, they should exhibit planning characteristics similar to the ones of simple sentences, the matrix clause and the subordinate clauses being planned in two steps. Twenty texts produced by French speaking adults were recorded. Pauses were characterized according to their duration and position. Globally, both predictions were confirmed. We conclude that supposedly complex sentences are not necessarily difficult to process.