Effects Of Phonotactic Probability Research Articles

Assessing the size of non-Māori-speakers' active Māori lexicon.

Most non-Māori-speaking New Zealanders are regularly exposed to Māori throughout their lives without seeming to build any extensive Māori lexicon; at best, they know a small number of words which are frequently used and sometimes borrowed into English. Here, we ask how many Māori words non-Māori-speaking New Zealanders know, in two ways: how many can they identify as real Māori words, and how many can they actively define? We show that non-Māori-speaking New Zealanders can readily identify many more Māori words than they can define, and that the number of words they can reliably define is quite small. This result adds crucial support to the idea presented in earlier work that non-Māori-speaking New Zealanders have implicit form-based (proto-lexical) knowledge of many Māori words, but explicit semantic (lexical) knowledge of few. Building on this distinction, we further ask how different levels of word knowledge modulate effects of phonotactic probability on the accessing of that knowledge, across both tasks and participants. We show that participants' implicit word knowledge leads to effects of phonotactic probability-and related effects of neighbourhood density-in a word/non-word discrimination task, but not in a more explicit task that requires the active definition of words. Similarly, we show that the effects of phonotactic probability on word/non-word discrimination are strong among participants who appear to lack explicit word knowledge, as indicated by their weak discrimination performance, but absent among participants who appear to have explicit word knowledge, as indicated by their strong discrimination performance. Together, these results suggest that phonotactic probability plays its strongest roles in the absence of explicit semantic knowledge.

Combining statistics: the role of phonotactics on cross-situational word learning

Language learners can rely on phonological and semantic information to learn novel words. Using a cross-situational word learning paradigm, we explored the role of phonotactic probabilities on word learning in ambiguous contexts. Brazilian-Portuguese speaking adults (N = 30) were exposed to two sets of word-object pairs. Words from one set of labels had slightly higher phonotactic probabilities than words from the other set. By tracking co-occurrences of words and objects, participants were able to learn word-object mappings similarly across both sets. Our findings contrast with studies showing a facilitative effect of phonotactic probability on word learning in non-ambiguous contexts.

Understanding Bilingual Word Learning: The Role of Phonotactic Probability and Phonological Neighborhood Density.

Previous research has shown that the language-learning mechanism is affected by bilingualism resulting in a novel word learning advantage for bilingual speakers. However, less is known about the factors that might influence this advantage. This article reports an investigation of 2 factors: phonotactic probability and phonological neighborhood density. Acquisition of 15 novel words varying in phonotactic probability and phonological neighborhood density was examined in high-proficiency, early onset, Mandarin-English bilinguals and English monolinguals. Both bilinguals and monolinguals demonstrated a significant effect of phonotactic probability and phonological neighborhood density. Novel word learning improved when the phonological neighborhood density was higher; in contrast, higher phonotactic probability resulted in worse learning. Although the bilingual speakers showed significantly better novel word learning than monolingual speakers, this did not interact with phonotactic probability and phonological neighborhood density manipulations. Both bilingual and monolingual word learning abilities are constrained by the same learning mechanisms. However, bilingual advantages may be underpinned by more effective allocation of cognitive resources due to their dual language experience.

The effects of phonotactic probability on auditory recognition of pseudo-words

A number of speech perception studies have been carried out to investigate how we process audio signals containing real words. However, comparatively fewer studies have been conducted looking at how we process audio signals containing phonotactically valid pseudo-words. Many traditional metrics, such as lexical frequency, used as predictors in this kind of analysis are difficult or impossible to calculate for pseudo-words, but other metrics like phonotactic probability can be calculated for such pseudo-words. Phonotactic probability is the likelihood that a particular sequence of phones occurs in a particular language, and it can be easily calculated using existing pronunciation and lexical frequency data. The present study uses the CMU Pronouncing Dictionary and the Google Ngram datasets to calculate phonotactic probability measures for each stimulus in an existing set of English auditory lexical decision responses and then statistically models the influence of phonotactic probability on the participants’ reaction times to the stimuli. This modeling shows a general trend of response times decreasing as phonotactic probability increases. The results are then framed in the greater picture of speech perception and word recognition overall.

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

Noisy conditions make auditory processing difficult. This study explores whether noisy conditions influence the effects of phonotactic probability (the likelihood of occurrence of a sound sequence) and neighborhood density (phonological similarity among words) on adults' word learning. Fifty-eight adults learned nonwords varying in phonotactic probability and neighborhood density in either an unfavorable (0-dB signal-to-noise ratio [SNR]) or a favorable (+8-dB SNR) listening condition. Word learning was assessed using a picture naming task by scoring the proportion of phonemes named correctly. The unfavorable 0-dB SNR condition showed a significant interaction between phonotactic probability and neighborhood density in the absence of main effects. In particular, adults learned more words when phonotactic probability and neighborhood density were both low or both high. The +8-dB SNR condition did not show this interaction. These results are inconsistent with those from a prior adult word learning study conducted under quiet listening conditions that showed main effects of word characteristics. As the listening condition worsens, adult word learning benefits from a convergence of phonotactic probability and neighborhood density. Clinical implications are discussed for potential populations who experience difficulty with auditory perception or processing, making them more vulnerable to noise.

The effect of phonotactic probability and neighbourhood density on pseudoword learning in 6- and 7-year-old children

The aim of this study was to examine the influence of phonotactic probability (PP) and neighbourhood density (ND) on pseudoword learning in 17 Dutch-speaking typically developing children (mean age 7;2). They were familiarized with 16 one-syllable pseudowords varying in PP (high vs low) and ND (high vs low) via a storytelling procedure. The participants were tested on their production and comprehension of the pseudowords on three testing sessions: immediately after training, after a consolidation period without further training and after a one week retention period during which one more training session was given. The results show that both in production and comprehension PP had a significant influence on pseudowords with low ND: pseudowords in the condition with converging characteristics (low PP – low ND) were learned significantly better than those in the high PP – low ND condition. No effect of PP was found for pseudowords high in ND. These results give cross-linguistic support for earlier English findings that convergent PP/ND (low PP – low ND) facilitates triggering word learning in children.

The influence of word characteristics on the vocabulary of children with cochlear implants.

The goal of this study was to explore the effects of phonotactic probability, word length, word frequency, and neighborhood density on the words known by children with cochlear implants (CIs) varying in vocabulary outcomes in a retrospective analysis of a subset of data from a longitudinal study of hearing loss. Generalized linear mixed modeling was used to examine the effects of these word characteristics at 3 time points: preimplant, postimplant, and longitudinal follow-up. Results showed a robust effect of neighborhood density across group and time, whereas the effect of frequency varied by time. Significant effects of phonotactic probability or word length were not detected. Taken together, these findings suggest that children with CIs may be able to use spoken language structure in a manner similar to their normal hearing counterparts, despite the differences in the quality of the input. The differences in the effects of phonotactic probability and word length imply a difficulty in initiating word learning and limited working memory ability in children with CIs.

Word recognition and nonword repetition in children with language disorders: the effects of neighborhood density, lexical frequency, and phonotactic probability.

The effects of neighborhood density (ND) and lexical frequency on word recognition and the effects of phonotactic probability (PP) on nonword repetition (NWR) were examined to gain insight into processing at the lexical and sublexical levels in typically developing (TD) children and children with developmental language problems. Tasks measuring NWR and word recognition were administered to 5 groups of children: 2 groups of TD children (5 and 8 years old), children with specific language impairment (SLI), children with reading impairment (RI), and children with SLI+RI (all 7-8 years old). High ND had a negative effect on word recognition in the older TD children and in the children with RI only. There was no ND effect in the younger children or in the children with SLI, who all had lower receptive vocabulary scores than the age-matched TD children and the RI groups. For all groups, NWR items with low PP were more difficult to repeat than items with high PP. This effect was especially pronounced in children with RI. Both the stage of vocabulary development and the type of language impairment (SLI or RI) impact the way ND and PP affect word recognition and NWR.

Effect of Phonotactic Probability and Neighborhood Density on Word-Learning Configuration by Preschoolers With Typical Development and Specific Language Impairment

In this study, the authors assessed the effects of phonotactic probability and neighborhood density on word-learning configuration by preschoolers with specific language impairment (SLI) and typical language development (TD). One hundred thirty-one children participated: 48 with SLI, 44 with TD matched on age and gender, and 39 with TD matched on vocabulary and gender. Referent identification and naming were assessed in a computer-based learning context. For referent identification, preschoolers with TD benefited from high phonotactic probability, and the younger group also benefited from low neighborhood density. In contrast, the SLI group benefited only from high neighborhood density. For naming, older preschoolers with TD benefited most from low-density words, younger preschoolers with TD benefited most from words with high phonotactic probability, and the SLI group showed no advantage. Phonotactic probability and neighborhood density had different effects on each group that may be related to children's ability to store well-specified word forms and to the size of their extant lexicon. The authors argue that cross-study comparisons of word learning are needed; therefore, researchers should describe word, referent, and learner characteristics and the learning context and should situate their studies in a triggering → configuration + engagement model of word learning.

Immediate auditory repetition of words and nonwords: an ERP study of lexical and sublexical processing.

ERPs were elicited to (1) words, (2) pseudowords derived from these words, and (3) nonwords with no lexical neighbors, in a task involving listening to immediately repeated auditory stimuli. There was a significant early (P200) effect of phonotactic probability in the first auditory presentation, which discriminated words and pseudowords from nonwords; and a significant somewhat later (N400) effect of lexicality, which discriminated words from pseudowords and nonwords. There was no reliable effect of lexicality in the ERPs to the second auditory presentation. We conclude that early sublexical phonological processing differed according to phonotactic probability of the stimuli, and that lexically-based redintegration occurred for words but did not occur for pseudowords or nonwords. Thus, in online word recognition and immediate retrieval, phonological and/or sublexical processing plays a more important role than lexical level redintegration.

Triggering word learning in children with Language Impairment: the effect of phonotactic probability and neighbourhood density

The effect of phonotactic probability (PP) and neighbourhood density (ND) on triggering word learning was examined in children with Language Impairment (3;04-6;09) and compared to Typically Developing children. Nonwords, varying PP and ND orthogonally, were presented in a story context and their learning tested using a referent identification task. Group comparisons with receptive vocabulary as a covariate found no group differences in overall scores or in the influence of PP or ND. Therefore, there was no evidence of atypical lexical or phonological processing. 'Convergent' PP/ND (High PP/High ND; Low PP/Low ND) was optimal for word learning in both groups. This bias interacted with vocabulary knowledge. 'Divergent' PP/ND word scores (High PP/Low ND; Low PP/High ND) were positively correlated with vocabulary so the 'divergence disadvantage' reduced as vocabulary knowledge grew; an interaction hypothesized to represent developmental changes in lexical-phonological processing linked to the emergence of phonological representations.

Early effects of neighborhood density and phonotactic probability of spoken words on event-related potentials

All current models of spoken word recognition propose that sound-based representations of spoken words compete with, or inhibit, one another during recognition. In addition, certain models propose that higher probability sublexical units facilitate recognition under certain circumstances. Two experiments were conducted examining ERPs to spoken words and nonwords simultaneously varying in phonotactic probability and neighborhood density. Results showed that the amplitude of the P2 potential was greater for high probability-density words and nonwords, suggesting an early inhibitory effect of neighborhood density. In order to closely examine the role of phonotactic probability, effects of initial phoneme frequency were also examined. The latency of the P2 potential was shorter for words with high initial-consonant probability, suggesting a facilitative effect of phonotactic probability. The current results are consistent with findings from previous studies using reaction time and eye-tracking paradigms and provide new insights into the time-course of lexical and sublexical activation and competition.

Word Learning by Preschoolers With SLI: Effect of Phonotactic Probability and Object Familiarity

In this study, the authors investigated whether previous findings of a low phonotactic probability/unfamiliar object word-learning advantage in preschoolers could be replicated, whether this advantage would be apparent at different "stages" of word learning, and whether findings would differ for preschoolers with specific language impairment (SLI) and typical development (TD). Participants included 114 children: 40 with SLI, 39 with TD matched for age and gender, and 35 with TD matched for expressive vocabulary and gender. Comprehension and production were assessed during word learning and at post-test for words that varied in phonotactic probability and object familiarity. Across groups, comprehension performance increased significantly from day 1 to day 2 and from day 2 to day 3, but there was no significant word/object type effect. Production performance increased significantly from day 1 to day 2, from day 2 to day 3, and from day 3 to day 4 for all groups, and there was a clear low phonotactic probability/unfamiliar object advantage during word learning but not at post-test. Results help to establish that preschoolers with TD and SLI show a low phonotactic probability/unfamiliar object production advantage during word learning that is not restricted to the first few exposures to words, but continues over time. This study illustrates how the interaction of phonological characteristics in nascent and extant words can affect word learning.

Using whole-word production measures to determine the influence of phonotactic probability and neighborhood density on bilingual speech production

Numerous lexical and sublexical factors have been reported to influence speech production in monolinguals (Storkel, 2001; Vitevitch, 2002); however, whole-word production analyses have rarely been used to measure such influences. The present study investigated the effects of phonotactic probability and neighborhood density on bilingual speech production using whole-word production measures (Ingram, 2002). Five typically developing English–Spanish bilingual children were administered a picture-naming task in English and Spanish in which stimuli varied in sublexical and lexical parameters. Their English and Spanish productions were compared with those of five age-matched monolingual English- and Spanish-speaking children, respectively. No differences were found between bilinguals and monolinguals in the respective languages; however, bilinguals evidenced greater phonological complexity in Spanish than English on words with low phonotactic probability and low neighborhood density. Whole-word approximation remained similar between languages. Findings are interpreted in the context of crosslinguistic influences of sublexical and lexical factors on speech production.

The independent effects of phonotactic probability and neighbourhood density on lexical acquisition by preschool children

The goal of this research was to disentangle effects of phonotactic probability, the likelihood of occurrence of a sound sequence, and neighbourhood density, the number of phonologically similar words, in lexical acquisition. Two-word learning experiments were conducted with 4-year-old children. Experiment 1 manipulated phonotactic probability while holding neighbourhood density and referent characteristics constant. Experiment 2 manipulated neighbourhood density while holding phonotactic probability and referent characteristics constant. Learning was tested at two time points (immediate vs. retention) in both a naming and referent identification task, although only data from the referent identification task were analysed due to poor performance in the naming task. Results showed that children were more accurate in learning rare sound sequences than common sound sequences and this was consistent across time points. In contrast, the effect of neighbourhood density varied by time. Children were more accurate in learning sparse sound sequences than dense sound sequences at the immediate test point but accuracy for dense sound sequences significantly improved by the retention test without further training. It was hypothesised that phonotactic probability and neighbourhood density influenced different cognitive processes that underlie lexical acquisition.

A cross-sectional comparison of the effects of phonotactic probability and neighborhood density on word learning by preschool children

Two experiments examined the effects of phonotactic probability and neighborhood density on word learning by 3-, 4-, and 5-year-old children. Nonwords orthogonally varying in probability and density were taught with learning and retention measured via picture naming. Experiment 1 used a within story probability/across story density exposure context. Experiment 2 used an across story probability/within story density exposure context. Results showed that probability and density interacted to create optimal learning conditions. Specifically, rare/sparse sound sequences appeared to facilitate triggering of word learning. In contrast, the optimal convergence for lexical configuration and engagement was dependent on exposure context. In particular, common sound sequences and dense neighborhoods were optimal when density was manipulated across stories, whereas rare sound sequences and sparse neighborhoods were optimal when density was manipulated within a story. Taken together, children’s phonological and lexical representations were hypothesized to be interdependent on one another resulting in a convergence of form characteristics for optimal word learning.

For Preschoolers, Lexical Access is Purely Lexical: Neighborhood Density Effects in Child Speech Perception and the Emergent Phoneme Hypothesis

Both infants and adults are sensitive to phonotactic probability, the statistical distribution of sequences of sound below the level of the whole word. A now classic study by Jusczyk, Luce, and Charles-Luce (1994) demonstrated that 9-month-olds (but not 6-month-olds) prefer to listen to sounds patterns that occur more frequently in their native language, suggesting that sensitivity to sublexical sound patterns develops rather rapidly during the second half of the first year of life. At the other end of the spectrum, work with adults has shown that adults process speech at both the sublexical and whole-word levels. Vitevitch and Luce (1998, 1999) presented adult speakers of American English with both words and nonwords of either high or low phonotactic probability/neighborhood density (these factors were always correlated, such that no stimuli had high phonotactic probability but low neighborhood density, or vice versa). In several different perceptually-oriented tasks, adults were found to process words from dense lexical neighborhoods more slowly than words from sparse lexical neighborhoods, while nonwords with high phonotactic probability were processed more quickly than nonwords with low phonotactic probability. Vitevitch and Luce argued that the frequency of sound patterns in the stimuli was either inhibitive or facilitatory depending on whether adults were processing at the lexical or sublexical level. Real words with frequent sound patterns were responded to more slowly due to a lexical competition effect, while nonwords with frequent sound patterns were responded to more quickly due to a phonotactic facilitation effect. Lexical competition and phonotactic facilitation were argued to be operative forces at all times, with the “winning” level of processing driving the response time; in essence, if stimuli were processed more quickly as words, a lexical competition effect was observed, whereas if they were processed more quickly via their component sounds, a phonotactic facilitation effect emerged. The picture is less clear regarding the effects of phonotactic probability on speech processing in

Word learning by children with phonological delays: Differentiating effects of phonotactic probability and neighborhood density

This study examined the ability of 20 preschool children with functional phonological delays and 34 age- and vocabulary-matched typical children to learn words differing in phonotactic probability (i.e., the likelihood of occurrence of a sound sequence) and neighborhood density (i.e., the number of words that differ from a target by one phoneme). Children were exposed to nonwords paired with novel objects in a story and learning was measured by a picture naming task. Results showed that both groups created lexical representations for rare sound sequences from sparse neighborhoods. However, only children with typical development appeared to build on this initial lexical representation to create a full representation of the word (i.e., lexical–semantic connection and semantic representation). It was hypothesized that creating a lexical representation may be too resource demanding for children with phonological delays, leaving few resources available to create a lexical–semantic connection and/or a semantic representation. Learning outcomes: The reader will be able to (1) define phonotactic probability; (2) define neighborhood density; (3) identify how these variables impact the word learning process in general; (4) identify potential areas of deficit in the word learning process for children with functional phonological delays.

Does phonological short-term memory causally determine vocabulary learning? Toward a computational resolution of the debate

The relationship between nonword repetition ability and vocabulary size and vocabulary learning has been a topic of intense research interest and investigation over the last two decades, following the demonstration that nonword repetition accuracy is predictive of vocabulary size (Gathercole & Baddeley, 1989). However, the nature of this relationship is not well understood. One prominent account posits that phonological short-term memory (PSTM) is a causal determinant both of nonword repetition ability and of phonological vocabulary learning, with the observed correlation between the two reflecting the effect of this underlying third variable (e.g., Baddeley, Gathercole, & Papagno, 1998). An alternative account proposes the opposite causality: that it is phonological vocabulary size that causally determines nonword repetition ability (e.g., Snowling, Chiat, & Hulme, 1991). We present a theory of phonological vocabulary learning, instantiated as a computational model. The model offers a precise account of the construct of PSTM, of performance in the nonword repetition task, of novel word form learning, and of the relationship between all of these. We show through simulation not only that PSTM causally affects both nonword repetition accuracy and phonological vocabulary size, but also that phonological vocabulary size causally affects nonword repetition ability. The plausibility of the model is supported by the fact that its nonword repetition accuracy displays effects of phonotactic probability and of nonword length, which have been taken as evidence for causal effects on nonword repetition accuracy of phonological vocabulary knowledge and PSTM, respectively. Thus the model makes explicit how the causal links posited by the two theoretical perspectives are both valid, in the process reconciling the two perspectives, and indicating that an opposition between them is unnecessary.

Differentiating Phonotactic Probability and Neighborhood Density in Adult Word Learning

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. 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. 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. 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.