Abstract: The grammatical planning scope in sentence production is an important issue and investigated by many psycholinguists. Regarding the grammatical level proper, the planning scope is often considered to be constrained by certain grammatical units, such as a clause (a sentence fragment consisting at least of a subject and a predicate), a subject noun phrase (the phrase including all nouns associated with the grammatical role of subject), or just a content word. Recently this planning scope was specified as a functional phrase. This issue, however, remains controversial. The goal of the current study is to thus clarify the scope of planning at the grammatical processing level of sentence production, especially to test the functional phrase hypothesis. In the current study the functional phrase hypothesis was tested with the picture-word interference paradigm. Native Mandarin Chinese speakers were asked to produce sentences with a prepositional phrase modified subject (e.g., ‘‘the dog under the flower is red’’) or sentences with a conjoined noun phrase as the subject (e.g., ‘‘the dog and the flower are both red’’) in response to vertical pairs of objects, and each display was accompanied by a visual distractor. The distractor could be categorically related or unrelated to the target picture on which it was presented, and was always unrelated to the other picture. Forty-three undergraduate and graduate students in total participated in this study and were asked to name pictures with the required syntactic structures as accurately and quickly as possible while ignoring the distractor. Two separate analyses were carried out with participants and items as random factors for onset latencies and error rates. There was a semantic interference effect for the first noun in both utterance formats, showing longer latencies in categorically related conditions compared to unrelated conditions. For the second noun of both utterance formats, the semantic interference effect was found in error rates rather than in onset latencies, no matter which SOA (Stimulus Onset Asynchrony) the condition was (0, 150, or 300ms). Meanwhile in the condition of SOA=0, a semantic facilitation effect in onset latencies was observed on the second noun of sentences with a conjoined noun phrase as the subject. These results suggest that the grammatical planning scope should be specified as that the lexical selection is radically incremental while the conceptual planning scope may encompass the functional phrase.

Key words: sentence production, planning scope, grammatical encoding, lexical selection, picture-word interference paradigm