Five theories of spoken word production that differ along the discreteness-interactivity dimension are evaluated. Specifically examined is the role that cascading activation, feedback, seriality, and interaction domains play in accounting for a set of fundamental observations derived from patterns of speech errors produced by normal and brain-damaged individuals. After reviewing the evidence from normal speech errors, case studies of 3 brain-damaged individuals with acquired naming deficits are presented. The patterns these individuals exhibit provide important constraints on theories of spoken naming. With the help of computer simulations of the 5 theories, the authors evaluate the extent to which the error patterns predicted by each theory conform with the empirical facts. The results support a theory of spoken word production that, although interactive, places important restrictions on the extent and locus of interactivity.

Research into spoken word production has often focused on the interaction of lexical selection processes and phonological planning. Less attention has been given to the relationship between phonological planning and articulatory processes. The current study considers evidence from the tongue-twister paradigm to investigate such potential interactions. Acoustic analyses of various parameters of obstruents voicing in tongue twister productions show that errors induced in tongue twisters leave acoustic ''traces'' of the intended target. For example, the voice-onset time of ''k'' [g] error tokens had a mean VOT that was longer than correctly produced ''g''[g] tokens, reflecting a trace of the voiceless [k] target. This effect is attributed to the cascade of partially activated phonological representations of the target consonant into articulatory processes. Consistent with this account, a post-hoc analysis revealed an additional influence of cascading activation from word-level processes; traces of the target were reduced in word outcomes relative to nonword outcomes. Finally, extension of these analyses to a set of secondary cues to obstruent voicing showed that non-local cues are not influenced by tongue twister production errors.Correspondence should be sent to Matthew Goldrick,

Many theories predict the presence of interactive effects involving information represented by distinct cognitive processes in speech production. There is considerably less agreement regarding the precise cognitive mechanisms that underlie these interactive effects. For example, are they driven by purely production-internal mechanisms (e.g., Dell, 1986) or do they reflect the influence of perceptual monitoring mechanisms on production processes (e.g., Roelofs, 2004)? Acoustic analyses reveal the phonetic realization of words is influenced by their word-specific properties-supporting the presence of interaction between lexical-level and phonetic information in speech production. A second experiment examines what mechanisms are responsible for this interactive effect. The results suggest the effect occurs on-line and is not purely driven by listener modeling. These findings are consistent with the presence of an interactive mechanism that is online and internal to the production system.A great deal of research has documented the presence of interactive effects-the interaction of distinct types of information represented by different cognitive processes -within both speech production and perception. The Ganong effect (Ganong, 1980) is a prototypical example; it illustrates the interaction of lexical and phonetic category information in speech perception. When presented with syllables whose initial consonants vary along a voice-onset time (VOT) continuum, listeners' identification of the initial phoneme is sensitive to whether the resulting syllable is a word or nonword. This is an interactive effect because the two types of information are assumed to be encoded by distinct processing stages in speech perception. The lexicality of a sound sequence is represented within lexical level processes, while the structure of phonetic categories is represented by pre-lexical processes (see McClelland, Mirman, and Holt, 2006, for a recent review of architectures based around this perspective; but see Gaskell and Marslen-Wilson, 1997, for an alternative perspective).Within the domain of speech production, many studies have focused on interactive effects involving semantic and phonological information. Most speech production theories assume that at least two distinct stages (representing different types of information) are involved in mapping semantic representations onto abstract, long-term memory representations of word form (e.g., mapping 'flying nocturnal mammal' to "bat"). The first processing stage involves selection of a word to express an intended concept, and the second involves retrieval of sound information corresponding to the selected word from long-term memory (Garrett, 1980). We refer to the former as lexical selection and the latter as lexical phonological processing. Critically, semantic information is represented within lexical selection processes while phonological information is represented within lexical phonetic processes. Chronometric studies, spontaneous speech error analyses, and studies of indiv...

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