The shape of things to come in speech production: Visual form interference during lexical access

Adaptive lexical processing of semantic competitors extends to alternative names: Evidence from blocked-cyclic picture naming

Naming a picture (e.g., "duck") in the context of semantically related pictures (e.g., "eagle," "stork," "parrot") takes longer than naming it in the context of unrelated pictures (e.g., "knave," "toast," "atlas"). Adaptive models of word production attribute this semantic interference effect in blocked-cyclic naming (BCN) to an adaptive mechanism that makes competitor words, (e.g., the semantically related word "eagle" for the target word "duck") which are activated but not selected for production, less accessible for future retrieval. Results from a recent picture-word-interference study, however, suggested that alternative names (e.g., "bird" for "duck") might be exempt from this mechanism, challenging adaptive lexical processing as a general mechanism. We tested whether converging evidence is obtained in BCN. In Experiment 1, we embedded pictures responded to with alternative (category) names (e.g., "bird") into contexts composed of pictures responded to with specific (exemplar) names (e.g., "duck," "eagle," "stork," and "parrot"). If alternative names are exempt from adaptive lexical processing, interference in the homogeneous context should be found for specific name items but not for alternative name items. In contrast to this prediction, there was similar-sized interference for both types of items. In Experiment 2, we replaced the alternative name items with unrelated items. For these items, interference was largely diminished, ruling out that the effect found in Experiment 1 is a general set effect. Overall, our data suggest that alternative names are not special with respect to adaptive lexical processing.

Neighing dogs: Semantic context effects of environmental sounds in spoken word production - a replication and extension

Semantic context effects are well established using both words and pictures as stimuli. One such effect, semantic interference, is observed in naming latencies when a categorically related distractor word or picture is presented together with a target picture (e.g., dog-LION). Recently, this effect has also been shown to occur when an environmental sound (e.g., a dog barking) is presented as an auditory distractor during picture naming and when a distractor picture is presented with a target sound for naming. The purpose of the current study was twofold: (1) to replicate the semantic interference effect in the picture-sound interference (PSI) paradigm and (2) determine whether a semantic interference effect is also observable when distractor words are presented with environmental sounds as target auditory objects for naming, using a novel sound-word interference (SWI) paradigm. We replicated the semantic interference effect in Experiment 1 with environmental sound distractors. Experiment 2 demonstrated significant semantic interference during an SWI paradigm for the first time. We discuss the implications of these results for our understanding of the origin and locus of the semantic interference effect according to current theories of lexical selection.

The Shape of Things to Come in Speech Production: A Functional Magnetic Resonance Imaging Study of Visual Form Interference during Lexical Access

Studies of context effects in speech production have shown that semantic feature overlap produces interference in naming of categorically related objects. In neuroimaging studies, this semantic interference effect is consistently associated with involvement of left superior and middle temporal gyri. However, at least part of this effect has recently been shown to be attributable to visual form similarity, as categorically related objects typically share visual features. This fMRI study examined interference produced by visual form overlap in the absence of a category relation in a picture-word interference paradigm. Both visually similar and visually dissimilar distractors led to increased BOLD responses in the left inferior frontal gyrus compared with the congruent condition. Naming pictures in context with a distractor word denoting an object visually similar in form slowed RTs compared with unrelated words and was associated with reduced activity in the left posterior middle temporal gyrus. This area is reliably observed in lexical level processing during language production tasks. No significant differential activity was observed in areas typically engaged by early perceptual or conceptual feature level processing or in areas proposed to be engaged by postlexical language processes, suggesting that visual form interference does not arise from uncertainty or confusion during perceptual or conceptual identification or after lexical processing. We conclude that visual form interference has a lexical locus, consistent with the predictions of competitive lexical selection models.