Differentiating Phonotactic Probability and Neighborhood Density in Adult Word Learning

Abstract

Purpose The purpose of this study was to differentiate effects of phonotactic probability, the likelihood of occurrence of a sound sequence, and neighborhood density, the number of words that sound similar to a given word, on adult word learning. A second purpose was to determine what aspect of word learning (viz., triggering learning, formation of an initial representation, or integration with existing representations) was influenced by each variable. Method Thirty-two adults were exposed to 16 nonwords paired with novel objects in a story context. The nonwords orthogonally varied in phonotactic probability and neighborhood density. Learning was measured following 1, 4, and 7 exposures in a picture-naming task. Partially correct (i.e., 2 of 3 phonemes correct) and completely correct responses (i.e., 3 of 3 phonemes correct) were analyzed together and independently to examine emerging and partial representations of new words versus complete and accurate representations of new words. Results Analysis of partially correct and completely correct responses combined showed that adults learned a lower proportion of high-probability nonwords than low-probability nonwords (i.e., high-probability disadvantage) and learned a higher proportion of high-density nonwords than low-density nonwords (i.e., high-density advantage). Separate analysis of partially correct responses yielded an effect of phonotactic probability only, whereas analysis of completely correct responses yielded an effect of neighborhood density only. Conclusions These findings suggest that phonological and lexical processing influence different aspects of word learning. In particular, phonotactic probability may aid in triggering new learning, whereas neighborhood density may influence the integration of new lexical representations with existing representations.

Lexical learning in bilingual adults: The relative importance of short-term memory for serial order and phonological knowledge

“…As an extension to the results of Masoura and Gathercole, our data show that serial order STM capacity remains an important predictor of foreign new word learning capacity, in addition to the influence of phonological knowledge for the given foreign language. These results also support the more general theoretical position offered by Metsala (1999) and Fowler (1990) (see also Storkel et al, 2006). This position considers that the increase of vocabulary knowledge in a given language favors segmentation and detailed representation of phonological knowledge, favoring in turn the acquisition of new phonological representations similar to that phonological knowledge.…”

“…An effect of sublexical phonological knowledge on new word learning has also been shown in monolingual adults (Storkel, Armbruster, & Hogan, 2006). Similarly, new words having a large number of lexical phonological neighbours (familiar words that differ from the target word by a single phoneme addition, substitution or deletion) appear to be learned faster than new words with a low density lexical neighbourhood (Storkel et al, 2006).…”

“…An effect of sublexical phonological knowledge on new word learning has also been shown in monolingual adults (Storkel, Armbruster, & Hogan, 2006). Similarly, new words having a large number of lexical phonological neighbours (familiar words that differ from the target word by a single phoneme addition, substitution or deletion) appear to be learned faster than new words with a low density lexical neighbourhood (Storkel et al, 2006). These findings support earlier theoretical proposals by Fowler (1991) and Metsala (1999), suggesting that growing vocabulary knowledge leads to the construction of phonological representations that are increasingly segmented and precise.…”

The Effects of Phonotactic Probability and Neighborhood Density on Adults' Word Learning in Noisy Conditions

“…On the other hand, if the input does not have an exact match with existing lexical representations in long-term memory, the listener identifies the word as novel, initiating word learning. This process of initiating word learning is referred to as triggering (e.g., Storkel, Armbrüster, & Hogan, 2006). Note, it is assumed that the individual sounds and sound sequences in a novel word have a matching phonological representation, indicating that the sounds are known sounds rather than novel sounds such as in, for example, foreign language learning, where the listener may encounter novel sounds.…”

Comparative Analysis of Networks of Phonologically Similar Words in English and Spanish

“…Psycholinguistic experiments have shown that the network characteristic of degree influences in English the cognitive processes of word recognition [12], word production [20], and word learning [21]. (Note that in the psycholinguistic literature degree is referred to as neighborhood density.)…”