Wheeldon, L. , Ohlson, N. , Ashby, A. & Gater, S.
Psychology. University of Bimingham. Birmingham, U.K.
Previous research has investigated the minimal processing scope employed during the grammatical encoding of spoken sentences. This research suggests that speakers prefer to grammatically encode a sentence initial phrase prior to speech onset and that this scope also applies to lexical access. The aim of this research was to investigate the extent to which speakers can extend their processing scope when they have advanced knowledge of lexical content. Three reaction time experiments will be reported which use a picture preview technique to investigate the effect of advanced lexical knowledge on processing scope. Speakers generated sentences in response to moving arrays of four pictured objects. The number of pictures in the sentence initial phrase was varied. In addition, speakers saw a 1s preview of one of the upcoming pictures. Speakers’ awareness of the linear position of the previewed picture was also varied. Significant effects of all variables were observed. The results demonstrate that speakers can extend their processing scope into the second phrase of a sentence in order to incorporate a known lexical item. However, they also show limitations to the extent of this ability and a disassociation between the scope of lexical access and the scope of syntactic planning.