Slipping on superlemmas: Multi-word lexical items in speech production

Only relatively recently have theories of speech production concerned themselves with the part idioms and other multi-word lexical items (MLIs) play in the processes of speech production. Two theories of speech production which attempt to account for the accessing of idioms in speech production are those of Cutting and Bock (1997) and superlemma theory (Sprenger, 2003; Sprenger, Levelt, & Kempen, 2006). Much of the data supporting theories of speech production comes either from time course experiments or from slips of the tongue (Bock & Levelt, 1994). The latter are of two kinds: experimentally induced (Baars, 1992) or naturally observed (Fromkin, 1980). Cutting and Bock use experimentally induced speech errors while Sprenger et al. use time course experiments. The missing data type that has a bearing on speech production involving MLIs is that of naturally occurring slips. In this study the impact of data taken from naturally observed slips involving English and Dutch MLIs are brought to bear on these theories. The data are taken initially from a corpus of just over 1000 naturally observed English slips involving MLIs (the Tuggy corpus). Our argument proceeds as follows. First we show that slips occur independent of whether or not there are MLIs involved. In other words, speech production proceeds in certain of its aspects as though there were no MLI present. We illustrate these slips from the Tuggy data. Second we investigate the predictions of superlemma theory. Superlemma theory (Sprenger et al., 2006) accounts for the selection of MLIs and how their properties enter processes of speech production. It predicts certain activation patterns dependent on a MLI being selected. Each such pattern might give rise to slips of the tongue. This set of predictions is tested against the Tuggy data. Each of the predicted activation patterns yields a significant number of slips. These findings are therefore compatible with a view of MLIs as single units in so far as their activation by lexical concepts goes. However, the theory also predicts that some slips are likely not to occur. We confirm that such slips are not present in the data. These findings are further corroborated by reference a second smaller dataset of slips involving Dutch MLIs (the Kempen corpus). We then use slips involving irreversible binomials to distinguish between the predictions of superlemma theory which are supported by slips involving irreversible binomials and the Cutting and Bock model’s predictions for slips involving these MLIs which are not.