Pictures were shown with superimposed word distractors of high and low frequency. Low-frequency distractors produced greater interference on picture naming than did high-frequency distractors. This distractor frequency effect was not affected by manipulations that facilitated or hindered distractor recognition. Interference was reduced for distractors that were read aloud several times prior to being shown in the picture-naming task. Together these findings suggest that the distractor frequency effect has its locus at some stage of lexical access for production. Other findings further constrain hypotheses about which level of speech production is involved in the effect. The distractor frequency effect has implications for models of lexical processing in speaking as well as for accounts of picture-word interference and the frequency effect.

How word production unfolds remains controversial. Serial models posit that phonological encoding begins only after lexical node selection, whereas cascade models hold that it can occur before selection. Both models were evaluated by testing whether unselected lexical nodes influence phonological encoding in the picture-picture interference paradigm. English speakers were shown pairs of superimposed pictures and were instructed to name one picture and ignore another. Naming was faster when target pictures were paired with phonologically related (bed-bell) than with unrelated (bed-pin) distractors. This suggests that the unspoken distractors exerted a phonological influence on production. This finding is inconsistent with serial models but in line with cascade ones. The facilitation effect was not replicated in Italian with the same pictures, supporting the view that the effect found in English was caused by the phonological properties of the stimuli.

We recorded the pupil diameters of participants performing the words’ color-naming Stroop task (i.e., naming the color of a word that names a color). Non-color words were used as baseline to firmly establish the effects of semantic relatedness induced by color word distractors. We replicated the classic Stroop effects of color congruency and color incongruency with pupillary diameter recordings: relative to non-color words, pupil diameters increased for color distractors that differed from color responses, while they reduced for color distractors that were identical to color responses. Analyses of the time courses of pupil responses revealed further differences between color-congruent and color-incongruent distractors, with the latter inducing a steep increase of pupil size and the former a relatively lower increase. Consistent with previous findings that have demonstrated that pupil size increases as task demands rise, the present results indicate that pupillometry is a robust measure of Stroop interference, and it represents a valuable addition to the cognitive scientist’s toolbox.

Eicture-word interference experiments conducted with Italian speakers investigated how determiners are selected in noun phrase (NP) production. Determiner production involves the selection of a noun's syntactic features (mass or count, gender), which specify the type of determiner to be selected, and the subsequent selection of a particular phonological form (e.g., the/a in English). The research focused on the syntactic feature of gender. Results repeatedly failed to replicate the gender-congruity effect in NP production reported with Dutch speakers (longer latencies for target-distractor noun pairs with contrasting as opposed to the same gender). It is proposed that the discrepant results reflect processing differences in lexical access in Italian and Dutch: The selection of determiners in Italian, but not in Dutch, depends on phonological properties of the word that follows it in the NP. Evidence consistent with this explanation was obtained in an experiment in which determiner selection in NP production was hindered by conflicting phonological information in the NP.Determiner production involves the selection of a set of grammatical features that jointly specify a determiner type, followed by the selection of a specific phonological form. For example, the production of the determiner "a" (as in "a car") requires the selection of the features indicating [nondefinite], [singular], and [count noun]. Some of the features are context specific (e.g., "definite"), and others are specified lexically (mass or count, gender). These features jointly specify the type of determiner that will be selected for production. Thus, the problem of determiner production can be broken down into two distinct problems: How are grammatical features represented and selected? How is the phonological form of a determiner selected? In this research we examined the issues of syntactic feature selection (Experiments 1-4) and determiner form selection (Experiments 3-5). The Selection of a Word's Syntactic FeaturesHow are a word's syntactic features represented and accessed? A modified version of the picture-word interference paradigm has been used to obtain results that are relevant to this issue (Schriefers, 1993). In the picture-word interference paradigm, a picture and a word are presented concomitantly to the reader. Numerous researchers have The research reported here was supported in part by National Institutes of Health Grant NS22201 and by a travel grant from Harvard University. We thank the Dipartimento di Psicologia dello Sviluppo e della Socializzazione of the University of Padua for providing the space and the equipment for conducting the experiments. We also thank Elisa Vian for her help in testing the participants of Experiment 3 and Stephen Lupker, two anonymous reviewers, and Kathryn Link for their helpful comments.Correspondence concerning this article should be addressed to either Michele Miozzo or Alfonso Caramazza, Department of Psychology, William James Hall, Harvard University, 33 Kirkland Street, Cambridge, Massachuse...