Publications

Abstract

In recent years, it has become clear that attention plays an important role in spoken word production. Some of this evidence comes from distributional analyses of reaction time (RT) in regular picture naming and picture-word interference. Yet we lack a mechanistic account of how the properties of RT distributions come to reflect attentional processes and how these processes may in turn modulate the amount of conflict between lexical representations. Here, we present a computational account according to which attentional lapses allow for existing conflict to build up unsupervised on a subset of trials, thus modulating the shape of the resulting RT distribution. Our process model resolves discrepancies between outcomes of previous studies on semantic interference. Moreover, the model's predictions were confirmed in a new experiment where participants' motivation to remain attentive determined the size and distributional locus of semantic interference in picture naming. We conclude that process modeling of RT distributions importantly improves our understanding of the interplay between attention and conflict in word production. Our model thus provides a framework for interpreting distributional analyses of RT data in picture naming tasks.

Abstract

The authors report six implicit priming experiments that examined the production of inflected forms. Participants produced words out of small sets in response to prompts. The words differed in form or shared word-initial segments, which allowed for preparation. In constant inflectional sets, the words had the same number of inflectional suffixes, whereas in variable sets the number of suffixes differed. In the experiments, preparation effects were obtained, which were larger in the constant than in the variable sets. Control experiments showed that this difference in effect was not due to syntactic class or phonological form per se. The results are interpreted in terms of a slot-and-filler model of word production, in which inflectional frames, on the one hand, and stems and affixes, on the other hand, are independently spelled out on the basis of an abstract morpho-syntactic specification of the word, which is followed by morpheme-to-frame association.

Abstract

Santiago, MacKay, Palma, and Rho (2000) report two picture naming experiments examining the role of syllable onset complexity and number of syllables in spoken word production. Experiment 1 showed that naming latencies are longer for words with two syllables (e.g., demon ) than one syllable (e.g., duck ), and longer for words beginning with a consonant cluster (e.g., drill ) than a single consonant (e.g., duck ). Experiment 2 replicated these findings and showed that the complexity of the syllable nucleus and coda has no effect. These results are taken to support MacKay's (1987) Node Structure theory and to refute models such as WEAVER++ (Roelofs, 1997a) that predict effects of word length but not of onset complexity and number of syllables per se. In this comment, I show that a re-analysis of the data of Santiago et al. that takes word length into account leads to the opposite conclusion. The observed effects of onset complexity and number of syllables appear to be length effects, supporting WEAVER++ and contradicting the Node Structure theory.

Abstract

Minimalist theories of spoken language planning hold that articulation starts when the first
speech segment has been planned, whereas non-minimalist theories assume larger units (e.g.,
Levelt, Roelofs, & Meyer, 1999a). Three experiments are reported, which were designed to distinguish
between these views using a newhybrid task that factorially manipulated preparation and
auditory priming of spoken language production. Minimalist theories predict no effect from
priming of non-initial segments when the initial segment of an utterance is already prepared;
observing such a priming effect would support non-minimalist theories. In all three experiments,
preparation and priming yielded main effects, and together their effects were additive. Preparation
of initial segments does not eliminate priming effects for later segments. These results challenge
the minimalist view. The findings are simulated by WEAVER++ (Roelofs, 1997b), which
employs the phonological word as the lower limit for articulation initiation.

Abstract

The control of language use has in its simplest form perhaps been most intensively studied using the color–word Stroop task. The authors review chronometric and neuroimaging evidence on Stroop task performance to evaluate two prominent, implemented models of control in naming and reading: GRAIN and WEAVER++. Computer simulations are reported, which reveal that WEAVER++ offers a more satisfactory account of the data than GRAIN. In particular, we report WEAVER++ simulations of the BOLD response in anterior cingulate cortex during Stroop performance. Aspects of single-word production and perception in the Stroop task are discussed in relation to the wider problem of the control of language use.

Abstract

The authors report a study in Dutch that used an on-line preparation paradigm to test the issue of semantic
dependency versus morphological autonomy in the production of polymorphemic words. Semantically
transparent complex words (like input in English) and semantically opaque complex words
(like invoice) showed clear evidence of morphological structure in word-form encoding, since both exhibited
an equally large preparation effect that was much greater than that for morphologically simple
words (like insect). These results suggest that morphemes may be planning units in the production of
complex words, without making a semantic contribution, thereby supporting the autonomy view. Language
production establishes itself as a domain in which morphology may operate “by itself” (Aronoff,
1994) without recourse to meaning.

Abstract

Preparing words in speech production is normally a fast and accurate process. We generate them two or three per second in fluent conversation; and overtly naming a clear picture of an object can easily be initiated within 600 msec after picture onset. The underlying process, however, is exceedingly complex. The theory reviewed in this target article analyzes this process as staged and feedforward. After a first stage of conceptual preparation, word generation proceeds through lexical selection, morphological and phonological encoding, phonetic encoding, and articulation itself. In addition, the speaker exerts some degree of output control, by monitoring of self-produced internal and overt speech. The core of the theory, ranging from lexical selection to the initiation of phonetic encoding, is captured in a computational model, called WEAVER + +. Both the theory and the computational model have been developed in interaction with reaction time experiments, particularly in picture naming or related word production paradigms, with the aim of accounting. for the real-time processing in normal word production. A comprehensive review of theory, model, and experiments is presented. The model can handle some of the main observations in the domain of speech errors (the major empirical domain for most other theories of lexical access), and the theory opens new ways of approaching the cerebral organization of speech production by way of high-temporal-resolution imaging.