Lexical Organization and Phonological Change in Treatment

Abstract

Word frequency and neighborhood density are properties of lexical organization that differentially influence spoken-word recognition. This study examined whether these same properties also affect spoken-word production, particularly as related to children with functional phonological delays. The hypothesis was that differential generalization would be associated with a word's frequency and its neighborhood density when manipulated as input in phonological treatment. Using a multiple baseline across subjects design, 8 children (aged 3;10 to 5;4) were randomly enrolled in 1 of 4 experimental conditions targeting errored sounds in high-frequency, low-frequency, high-density, or low-density words. Dependent measures were generalization of treated sounds and untreated sounds within and across manner classes as measured during and following treatment. Results supported a hierarchy of phonological generalization by experimental condition. The clinical implications lie in planning for generalization through the input presented in treatment. Theoretically, the results demonstrate that lexical organization of words in the mental lexicon interacts with phonological structure in learning.

Phonological Neighborhood and Word Frequency Effects in the Stuttered Disfluencies of Children Who Stutter

“…However, relative to the typically used standard for classifying words as high or low frequency (high: ≥100 per million; low: <100 per million; e.g., Morrisette & Gierut, 2002), both the stuttered and fluently produced words would seem to be sufficiently high in mean frequency (M = 6363.65 and 11992.17, respectively) for the effects of neighborhood density to be reduced. The fact that the children tended to produce more high frequency words is not surprising, considering that the (a) word samples were obtained from a naturalistic play setting in which word frequency was one of several dependent variables; (b) children were between the ages of 3;0 and 5;2, a time during which early acquired words, which tend to be high in frequency (Storkel, 2004), are more likely to occur in speech; and (c) the majority (71.4%) of the words sampled in this study were function words, which tend to be higher in frequency than content words (Pulvermüller, 1999).…”

“…However, another possible explanation for this effect, which has not been considered in the stuttering literature, can be derived from models of spoken word recognition, in which the effects of word frequency are thought to be directly related to processing demands (Morrisette & Gierut, 2002). Specifically, the processing load for high frequency words is thought to be reduced because "the path to retrieving these forms is well-established, as they occur so often in the input" (Morrisette & Gierut, 2002, p. 154).…”

“…Furthermore, of the few studies that have examined children's lexical representations, most have focused on word recognition processes, rather than speech production (e.g., Munson, Swenson, & Manthei, 2005). Nevertheless, findings from most speech production studies indicate that the lexical factors of word frequency, neighborhood density, and/or neighborhood frequency have the same general pattern in children as in adults (Gierut, 2001;Gierut, Morrisette, & Champion, 1999;German & Newman, 2004;Morrisette & Gierut, 2002;Newman & German, 2002;Stemberger, 1984;Storkel & Morrisette, 2002). …”

Age of acquisition and repetition priming effects on picture naming of children who do and do not stutter

“…Activation spreading is presumed to occur through excitatory connections from semantic to lemma to lexeme levels, with the strength of these connections determined by experience and learning (Dell, Chang, & Griffin, 1999;Dell, Schwartz, Martin, Saffran, & Gagnon, 1997;Schwartz, Dell, Martin, Gahl, & Sobel, 2006). Thus, a word's lemma and lexeme could be fully formed and easy to access, but the connection or pathway to retrieving these representations could be weak, increasing the amount of time and energy needed for word processing (Harley & Bown, 1998;Morrisette & Gierut, 2002).…”

Phonological Complexity and Language Learnability

“…As another example, the items used in treatment and the way in which they are presented to a child may factor into a working definition of treatment complexity. These may encompass questions about the efficacy of real words versus nonwords, tabletop versus electronic displays, or the lexical properties of the input itself (e.g., a given word's frequency, its age of acquisition, or its relationship to other rhyming words in the language; Leonard & Ritterman, 1971;Martin & Gierut, 2004;Morrisette & Gierut, 2002;Shriberg, Kwiatkowski, & Snyder, 1989Storkel, 2004;Tyler & Edwards, 1993). Moreover, the mode and timing of a clinician's input or feedback may further bear on treatment complexity.…”