Studies of the production of selected sentences show that occasional errors of subject-verbal chords that make locotors occur earlier when a single head name is followed by a plural, as happened in The Producer of the Adventure movies, than when a plural head is followed by a singular (z.B. Bock-Miller, 1991). The importance of this asymmetrical error pattern depends on whether plural interference occurs only during sentence preparation or whether it also manifests itself in sentence-understanding tasks. Five reading experiments have shown that: (1) reading time models reflect the asymmetry of the production error; (2) a term that is conceptually plural but grammatically singular (z.B. the label on the bottles) produces no more reading difficulties than a conceptual and grammatically singular product, a result imitating the results of Bock et miller`s 1991 production; (3) The intervention of a plural between the two depends on a close syntactic link with the head-nostin phrase (z.B the owner of the house who harasses the brokers). These results suggest that, although the calculation of the chord may be performed differently in both systems, interference can occur when a structure is calculated with a singularized head and an intermediate plural, either during production or comprehension. Now is the time to accept these verbs with a negative contraction of the subject! This research was conducted, while the first and second authors were supported by Grant DC-01409, a research and training fellowship funded by the National Institute on Deafness and Other Communicative Disorders at the National Center for Neurogenic Communication Disorders, University of Arizona. During this period, the third author was supported by the Cognitive Science Program, University of Arizona. We thank Brian Butterworth and two anonymous critics for their comments on an earlier version of this article. We are grateful to Jason Barker for testing, stimuli preparation and data analysis, and Martha Barron, Nicole Diamond, Lea Ann Hald and Tracy Love for the subjects. Thanks also to Neal Pearlmutter for talking with us about the results of his experiences with Kay Bock and Susan Garnsey.
The results of Experiment 1 were presented at the Annual Conference on Human Sentences, New York, NY, March 1994.