Lexical Planning In Second Language Sentence Production:Hierarchical Or Serial?

Speech production usually consists of three stages.Specifically,in the formulating stage,the preverbal message will be grammatically and phonologically encoded.The process of grammatical encoding involves lexical retrieval and syntactic formulation.There is a widespread agreement that speech production unfolds incrementally.For previous studies on the process of grammatical encoding,most of them focused on the size of planning scope,i.e.,whether it is a word,or as large as a phrase or clause,or it is flexible,which is still a controversial issue.However,few studies paid attention to the structure of lexical planning at the grammatical encoding stage,i.e.,whether it is modulated by the linear order or by the hierarchical relationships of the utterance.Furthermore,no studies have been conducted to investigate the manner of lexical planning in L2 sentence production.Therefore,this research focused on this issue and the following two research questions were put forward: 1)Is lexical planning modulated by the linear order or by the hierarchical relationships of an utterance for Chinese English as a second language(ESL)learners in second language sentence production? 2)Does English proficiency level affect Chinese ESL learners’ planning strategies in second language sentence production?To answer these questions,Lee et al.’s paradigm was employed in two experiments.The relative clause attachment ambiguities would allow us to manipulate the structural dependencies while keeping the surface order constant across different attachment types.The codability of the relative clause noun C was controlled to index the planning points of the C during L2 sentence production.We recruited two groups of Chinese ESL learners with different English proficiency(one with high proficiency of English and the other with lower-intermediate proficiency of English).In both experiments,participants were instructed to describe complex displays using ambiguous relative clause.In Experiment one,subjects were offered five seconds to preview each display before speaking and then they should describe critical displays by using corresponding sentence structure “Click on the A of the B(who’s/that’s)below the C”.In Experiment two,subjects were not provided with the five-second preview period and they should describe critical displays using the corresponding sentence structure “The A of the B(who’s/that’s)below the C”.Speech initiation times and durations of critical regions in both experiments were measured and analyzed.Taken together,the findings of these two experiments were as follows: 1)significant codability effects were found at the duration of relative clause in both experiments,indicating that Chinese ESL learners follow a linear strategy of lexical planning in L2 sentence production,without regard to time pressure and the hierarchical relationships;2)for the high proficiency group,reliable attachment effects were found on the duration of relative clause only in Experiment two,suggesting that structural planning is flexible and can be affected by time pressure and sentence structures.