Syntactic and nonsyntactic planning of morphology in speech production

A sentence-pair repetition procedure was used to examine how inflected and derived words are represented during speech planning. Three experiments tested the hypotheses that inflectional structure is represented in syntactic plans for speech, and that derivational structure is not, as assumed by speech production theories. Participants performed aloud repetitions of pairs of sentences that matched in all structural aspects (Congruent) or differed in the morphological affixation of one critical word (Incongruent). In the Syntactically Engaged condition, the critical words filled their usual syntactic roles. In the Syntactically Disengaged condition, the critical words were merely cited (e.g., Say {dollar}underline{lcub}walked{rcub}{dollar} first.), so they should not affect the syntactic plan. Production theories predict that repetition of sentences with incongruent inflections should be more difficult than repetition of sentences with congruent inflections, especially in the Syntactically Engaged condition. For derivational morphology, the theories stipulate no syntactic engagement of affixes, but a separate phonological competition process may produce a general congruence cost for these materials.; Experiment 1 studied inflectional morphology using a discrete repetition task, in which participants performed isolated repetitions of sentence pairs. Production durations showed an effect of Congruence but no interaction with Syntactic Engagement, suggesting that the task may be insufficiently sensitive to syntactic planning processes. Accordingly, Experiments 2 and 3 adopted the continuous repetition procedure employed in previous production planning research to examine inflectional and derivational morphology, respectively. Overall, results confirmed predictions and supported the hypotheses that inflectional structure is represented in syntactic plans, and that derivational structure is not. In addition, the experiments demonstrate that the continuous repetition task can be applied successfully to study syntactic and morphological planning, opening the door for experiments addressing finer details of the processes.