Cross‐Situational Learning of Minimal Word Pairs

Cross‐situational statistical learning of words involves tracking co‐occurrences of auditory words and objects across time to infer word‐referent mappings. Previous research has demonstrated that learners can infer referents across sets of very phonologically distinct words (e.g., WUG, DAX), but it remains unknown whether learners can encode fine phonological differences during cross‐situational statistical learning. This study examined learners’ cross‐situational statistical learning of minimal pairs that differed on one consonant segment (e.g., BON–TON), minimal pairs that differed on one vowel segment (e.g., DEET–DIT), and non‐minimal pairs that differed on two or three segments (e.g., BON–DEET). Learners performed above chance for all pairs, but performed worse on vowel minimal pairs than on consonant minimal pairs or non‐minimal pairs. These findings demonstrate that learners can encode fine phonetic detail while tracking word‐referent co‐occurrence probabilities, but they suggest that phonological encoding may be weaker for vowels than for consonants.     

Vowel bias in Danish word‐learning: processing biases are language‐specific

The present study explored whether the phonological bias favoring consonants found in French‐learning infants and children when learning new words (Havy & Nazzi, 2009; Nazzi, 2005) is language‐general, as proposed by Nespor, Peña and Mehler (2003), or varies across languages, perhaps as a function of the phonological or lexical properties of the language in acquisition. To do so, we used the interactive word‐learning task set up by Havy and Nazzi (2009), teaching Danish‐learning 20‐month‐olds pairs of phonetically similar words that contrasted either on one of their consonants or one of their vowels, by either one or two phonological features. Danish was chosen because it has more vowels than consonants, and is characterized by extensive consonant lenition. Both phenomena could disfavor a consonant bias. Evidence of word‐learning was found only for vocalic information, irrespective of whether one or two phonological features were changed. The implication of these findings is that the phonological biases found in early lexical processing are not language‐general but develop during language acquisition, depending on the phonological or lexical properties of the native language.     

Phonological priming in adults who stutter

The purpose of this study was to compare the speed of phonological encoding between adults who stutter (AWS) and adults who do not stutter (ANS). Fifteen male AWS and 15 age- and gender-matched ANS participated in the study. Speech onset latency was obtained for both groups and stuttering frequency was calculated for AWS during three phonological priming tasks: (1) heterogeneous, during which the participants' single-word verbal responses differed phonemically; (2) C-homogeneous, during which the participants' response words shared the initial consonant; and (3) CV-homogeneous, during which the participants' response words shared the initial consonant and vowel. Response words containing the same C and CV patterns in the two homogeneous conditions served as phonological primes for one another, while the response words in the heterogeneous condition did not. During each task, the participants produced a verbal response after being visually presented with a semantically related cue word, with cue-response pairs being learned beforehand. The data showed that AWS had significantly longer speech onset latency when compared to ANS in all priming conditions, priming had a facilitating effect on word retrieval for both groups, and there was no significant change in stuttering frequency across the conditions for AWS. This suggests that phonological encoding may play no role, or only a minor role, in stuttering. EDUCATIONAL OBJECTIVES: The reader will be able to: (1) describe previous research paradigms that have been used to assess phonological encoding in adults and children who stutter; (2) explain performance similarities and differences between adults who do and do not stutter during various phonological priming conditions; (3) compare the present findings to past research that examined the relationship between phonological encoding and stuttering.     

Retrieval Dynamics and Retention in Cross‐Situational Statistical Word Learning

Previous research on cross‐situational word learning has demonstrated that learners are able to reduce ambiguity in mapping words to referents by tracking co‐occurrence probabilities across learning events. In the current experiments, we examined whether learners are able to retain mappings over time. The results revealed that learners are able to retain mappings for up to 1 week later. However, there were interactions between the amount of retention and the different learning conditions. Interestingly, the strongest retention was associated with a learning condition that engendered retrieval dynamics that initially challenged the learner but eventually led to more successful retrieval toward the end of learning. The ease/difficulty of retrieval is a critical process underlying cross‐situational word learning and is a powerful example of how learning dynamics affect long‐term learning outcomes.     

Influences of vowel and tone variation on emergent word knowledge: a cross‐linguistic investigation

To learn words, infants must be sensitive to native phonological contrast. While lexical tone predominates as a source of phonemic contrast in human languages, there has been little investigation of the influences of lexical tone on word learning. The present study investigates infants’ sensitivity to tone mispronunciations in two groups of infants. For one group (Chinese learners), tone is phonemic in their native language, and for the second group (English learners), tone is non‐phonemic and constituted suprasegmental variation. In Experiment 1, English learners were trained on novel word–object pairings and tested on their recognition of correct pronunciations, tone and vowel mispronunciations of these words at 18 and 24 months. In Experiment 2a, bilingual English‐Chinese learners were tested on a similar task translated into Chinese at the same age intervals. Results demonstrate that non‐tonal learners treated tonal and vowel substitutions alike as mispronunciations at 18 months but only treated vowel substitutions as mispronunciations at 24 months. Tonal learners treated both tonal and vowel substitutions as mispronunciations at both ages. In Experiment 2b, bilingual non‐tone language learners were tested on the same set of tasks replicating a similar set of results as monolingual non‐tone language learners (Experiment 1). Findings point to an early predisposition to treat tone as a defining characteristic of words regardless of its lexical relevance at 18 months. Between 18 and 24 months, learners appear to ascribe lexical relevance to tone in a language‐specific manner. The current study identifies the influences of tone variation on memories for newly learned words and the time period during which lexical tone – a highly frequent constituent of human languages – actually becomes lexical for early learners. Findings are contextualized with prevailing models of the developing lexicon.     

The Role of the Phonological Loop in English Word Learning: A Comparison of Chinese ESL Learners and Native Speakers

Although the role of the phonological loop in word-retention is well documented, research in Chinese character retention suggests the involvement of non-phonological encoding. This study investigated whether the extent to which the phonological loop contributes to learning and remembering visually introduced words varies between college-level Chinese ESL learners (N = 20) and native speakers of English (N = 20). The groups performed a paired associative learning task under two conditions (control versus articulatory suppression) with two word types (regularly spelled versus irregularly spelled words) differing in degree of phonological accessibility. The results demonstrated that both groups’ recall declined when the phonological loop was made less available (with irregularly spelled words and in the articulatory suppression condition), but the decline was greater for the native group. These results suggest that word learning entails phonological encoding uniformly across learners, but the contribution of phonology varies among learners with diverse linguistic backgrounds.     

Word learning and phonetic processing in preschool-age children

Consonants and vowels have been shown to play different relative roles in different processes, including retrieving known words from pseudowords during adulthood or simultaneously learning two phonetically similar pseudowords during infancy or toddlerhood. The current study explores the extent to which French-speaking 3- to 5-year-olds exhibit a so-called “consonant bias” in a task simulating word acquisition, that is, when learning new words for unfamiliar objects. In Experiment 1, the to-be-learned words differed both by a consonant and a vowel (e.g., /byf/-/duf/), and children needed to choose which of the two objects to associate with a third one whose name differed from both objects by either a consonant or a vowel (e.g., /dyf/). In such a conflict condition, children needed to favor (or neglect) either consonant information or vowel information. The results show that only 3-year-olds preferentially chose the consonant identity, thereby neglecting the vowel change. The older children (and adults) did not exhibit any response bias. In Experiment 2, children needed to pick up one of two objects whose names differed on either consonant information or vowel information. Whereas 3-year-olds performed better with pairs of pseudowords contrasting on consonants, the pattern of asymmetry was reversed in 4-year-olds, and 5-year-olds did not exhibit any significant response bias. Interestingly, girls showed overall better performance and exhibited earlier changes in performance than boys. The changes in consonant/vowel asymmetry in preschoolers are discussed in relation with developments in linguistic (lexical and morphosyntactic) and cognitive processing.     

聋人双字词音位识别的实验研究

聋人能利用视觉音素意识解码词汇语音。与健听人音位位置效应一致,聋人对汉字声母更敏感,但双字词中是否也有类似的声母优势还不清楚。采用音位识别任务探讨聋人双字词识别的声母优势及其原因,研究一利用编码方式考察指拼的作用,发现了声母识别优势,表明聋人能利用字母和指拼两种方式解码双字词语音且编码方式不影响声母优势;研究二进一步利用汉字位置探讨音位序列加工对声母识别优势的作用,结果发现了声母优势、首字优势及首字声母优势,表明聋人识别双字词音位在汉字水平、汉字音节内水平都遵循从左至右的序列加工,与健听人一致,同时还受指拼声母的特殊影响。整个研究表明,聋人识别汉字语音建立在视觉音素意识基础上,双字词的声母识别优势受指拼声母强化、双字词汉字位置效应、音节内音位位置效应的共同作用。     

Offline consolidation supersedes prior knowledge benefits in children's (but not adults’) word learning

Prior linguistic knowledge is proposed to support the acquisition and consolidation of new words. Adults typically have larger vocabularies to support word learning than children, but the developing brain shows enhanced neural processes that are associated with offline memory consolidation. This study investigated contributions of prior knowledge to initial word acquisition and consolidation at different points in development, by teaching children and adults novel words (e.g., ballow) that varied in the number of English word‐form “neighbours” (e.g., wallow, bellow). Memory for the novel word‐forms was tested immediately after training, the next day and 1 week later, to assess the time‐course of prior knowledge contributions. Children aged 7–9 years (Experiments 1, 3) and adults (Experiment 2) recalled words with neighbours better than words without neighbours when tested immediately after training. However, a period of offline consolidation improved overall recall and reduced the influence of word‐form neighbours on longer term memory. These offline consolidation benefits were larger in children than adults, supporting theories that children have a greater propensity for consolidating phonologically distinctive language information. Local knowledge of just a single word‐form neighbour was enough to enhance learning, and this led to the individual differences in word recall that were related to adults’ global vocabulary ability. The results support the proposal that the relative contributions of different learning mechanisms change across the lifespan, and highlight the importance of testing theoretical models of word learning in the context of development.     

When Stronger Knowledge Slows You Down: Semantic Relatedness Predicts Children's Co‐Activation of Related Items in a Visual Search Paradigm

A large literature suggests that the organization of words in semantic memory, reflecting meaningful relations among words and the concepts to which they refer, supports many cognitive processes, including memory encoding and retrieval, word learning, and inferential reasoning. The co‐activation of related items has been proposed as a mechanism by which semantic knowledge influences cognition, and contemporary accounts of semantic knowledge propose that this co‐activation is graded—that it depends on how strongly related the items are in semantic memory. Prior research with adults yielded evidence supporting this prediction; however, there is currently no evidence of graded co‐activation early in development. This study provides the first evidence that in children the co‐activation of related items depends on their relational strength in semantic memory. Participants (N = 84, age range: 3–9 years) were asked to identify a target (e.g., bone) amid distractors. Children's responses were slowed down by the presence of a related distractor (e.g., puppy) relative to unrelated distractors (e.g., flower)—suggesting that children co‐activated related items upon hearing the name of the target. Importantly, the degree of this co‐activation was predicted by the strength of the target–distractor relation, such that distractors more strongly related to the targets slowed down children to a larger extent. These findings have important implications for understanding how organized semantic knowledge affects other cognitive processes across development.     

Morphological knowledge as revealed in children's spelling accuracy and reports of spelling strategies

The goal of the current research was to assess whether children can make strategic use of morphological relations among words to spell. French-speaking children in Grade 4 spelled three word types: (a) phonological words that had regular phoneme-grapheme correspondences, (b) morphological words that had silent consonant endings for which a derivative revealed the silent ending, and (c) lexical words that had silent consonant endings for which no familiar derivative revealed the ending. Children were also asked to provide immediate retrospective reports of the strategies used to spell each word. Two experiments (Ns = 46 and 39) were conducted. As expected, children in Grade 4 spelled phonological words more accurately than they did words with silent consonant endings. In addition, children spelled morphological words more accurately than they did lexical words. Reports of using retrieval were associated with accurate performance across word types. Importantly, reports of using morphological strategies to spell morphological words were associated with a similar level of accuracy, as were reports of using retrieval. Even though children reported using a phonological strategy frequently across all word types, this strategy was associated with accurate performance only for spelling phonological words. Experiment 2 replicated the results of Experiment 1 with another set of stimuli and also showed that children's morphological awareness predicted their spelling accuracy for morphological words as well as the reported frequency of morphological strategy use. In sum, the findings revealed that most children showed evidence of adaptive strategy use.     

On the nature of consonant/vowel differences in letter position coding: Evidence from developing and adult readers

In skilled adult readers, transposed‐letter effects (jugde ‐JUDGE ) are greater for consonant than for vowel transpositions. These differences are often attributed to phonological rather than orthographic processing. To examine this issue, we employed a scenario in which phonological involvement varies as a function of reading experience: A masked priming lexical decision task with 50‐ms primes in adult and developing readers. Indeed, masked phonological priming at this prime duration has been consistently reported in adults, but not in developing readers (Davis, Castles, & Iakovidis, 1998). Thus, if consonant/vowel asymmetries in letter position coding with adults are due to phonological influences, transposed‐letter priming should occur for both consonant and vowel transpositions in developing readers. Results with adults (Experiment 1) replicated the usual consonant/vowel asymmetry in transposed‐letter priming. In contrast, no signs of an asymmetry were found with developing readers (Experiments 2–3). However, Experiments 1–3 did not directly test the existence of phonological involvement. To study this question, Experiment 4 manipulated the phonological prime‐target relationship in developing readers. As expected, we found no signs of masked phonological priming. Thus, the present data favour an interpretation of the consonant/vowel dissociation in letter position coding as due to phonological rather than orthographic processing.     

Formal distinctiveness of high- and low-imageability nouns: analyses and theoretical implications

Words associated with perceptually salient, highly imageable concepts are learned earlier in life, more accurately recalled, and more rapidly named than abstract words (R. W. Brown, 1976; Walker & Hulme, 1999). Theories accounting for this concreteness effect have focused exclusively on semantic properties of word referents. A novel possibility is that word structure may also contribute to the effect. We report a corpus-based analysis of the phonological and morphological structures of a large set of nouns with imageability ratings (N = 2,023). High- and low-imageability nouns differed by length, etymology, prosody, affixation, phonological neighborhood density, and rates of consonant clustering. On average, nouns denoting abstract concepts were longer, more derivationally complex, and emerged in English from a different distribution of languages than did concrete nouns. We address implications for interactivity of word form and meaning as pertain to theories of word concreteness, lexical acquisition, and word processing.     

Why Choo‐Choo Is Better Than Train: The Role of Register‐Specific Words in Early Vocabulary Growth

Across languages, lexical items specific to infant‐directed speech (i.e., ‘baby‐talk words’) are characterized by a preponderance of onomatopoeia (or highly iconic words), diminutives, and reduplication. These lexical characteristics may help infants discover the referential nature of words, identify word referents, and segment fluent speech into words. If so, the amount of lexical input containing these properties should predict infants’ rate of vocabulary growth. To test this prediction, we tracked the vocabulary size in 47 English‐learning infants from 9 to 21 months and examined whether the patterns of growth can be related to measures of iconicity, diminutives, and reduplication in the lexical input at 9 months. Our analyses showed that both diminutives and reduplication in the input were associated with vocabulary growth, although measures of iconicity were not. These results are consistent with the hypothesis that phonological properties typical of lexical input in infant‐directed speech play a role in early vocabulary growth.     

Adaptation to novel accents by toddlers

Word recognition is a balancing act: listeners must be sensitive to phonetic detail to avoid confusing similar words, yet, at the same time, be flexible enough to adapt to phonetically variable pronunciations, such as those produced by speakers of different dialects or by non‐native speakers. Recent work has demonstrated that young toddlers are sensitive to phonetic detail during word recognition; pronunciations that deviate from the typical phonological form lead to a disruption of processing. However, it is not known whether young word learners show the flexibility that is characteristic of adult word recognition. The present study explores whether toddlers can adapt to artificial accents in which there is a vowel category shift with respect to the native language. Nineteen‐month‐olds heard mispronunciations of familiar words (e.g. vowels were shifted from [a] to [æ]: ‘dog’ pronounced as ‘dag’). In test, toddlers were tolerant of mispronunciations if they had recently been exposed to the same vowel shift, but not if they had been exposed to standard pronunciations or other vowel shifts. The effects extended beyond particular items heard in exposure to words sharing the same vowels. These results indicate that, like adults, toddlers show flexibility in their interpretation of phonological detail. Moreover, they suggest that effects of top‐down knowledge on the reinterpretation of phonological detail generalize across the phono‐lexical system.     

A Bootstrapping Model of Frequency and Context Effects in Word Learning

Prior research has shown that people can learn many nouns (i.e., word–object mappings) from a short series of ambiguous situations containing multiple words and objects. For successful cross‐situational learning, people must approximately track which words and referents co‐occur most frequently. This study investigates the effects of allowing some word‐referent pairs to appear more frequently than others, as is true in real‐world learning environments. Surprisingly, high‐frequency pairs are not always learned better, but can also boost learning of other pairs. Using a recent associative model (Kachergis, Yu, & Shiffrin, 2012), we explain how mixing pairs of different frequencies can bootstrap late learning of the low‐frequency pairs based on early learning of higher frequency pairs. We also manipulate contextual diversity, the number of pairs a given pair appears with across training, since it is naturalistically confounded with frequency. The associative model has competing familiarity and uncertainty biases, and their interaction is able to capture the individual and combined effects of frequency and contextual diversity on human learning. Two other recent word‐learning models do not account for the behavioral findings.     

“Mummy,keep it steady”: phonetic variation shapes word learning at 15 and 17 months

Fifteen‐month‐olds have difficulty detecting differences between novel words differing in a single vowel. Previous work showed that Australian English (AusE) infants habituated to the word‐object pair DEET detected an auditory switch to DIT and DOOT in Canadian English (CanE) but not in their native AusE (Escudero et al., 2014 ). The authors speculated that this may be because the vowel inherent spectral change variation (VISC) in AusE DEET is larger than in CanE DEET. We investigated whether VISC leads to difficulty in encoding phonetic detail during early word learning, and whether this difficulty dissipates with age. In Experiment 1, we familiarized AusE‐learning 15‐month‐olds to AusE DIT, which contains smaller VISC than AusE DEET. Unlike infants familiarized with AusE DEET (Escudero et al., 2014 ), infants detected a switch to DEET and DOOT. In Experiment 2, we familiarized AusE‐learning 17‐month‐olds to AusE DEET. This time, infants detected a switch to DOOT, and marginally detected a switch to DIT. Our acoustic analysis showed that AusE DEET and DOOT are differentiated by the second vowel formant, while DEET and DIT can only be distinguished by their changing dynamic properties throughout the vowel trajectory. Thus, by 17 months, AusE infants can encode highly dynamic acoustic properties, enabling them to learn the novel vowel minimal pairs that are difficult at 15 months. These findings suggest that the development of word learning is shaped by the phonetic properties of the specific word minimal pair.     

The Interplay of Cross‐Situational Word Learning and Sentence‐Level Constraints

A variety of mechanisms contribute to word learning. Learners can track co‐occurring words and referents across situations in a bottom‐up manner (cross‐situational word learning, CSWL). Equally, they can exploit sentential contexts, relying on top–down information such as verb–argument relations and world knowledge, offering immediate constraints on meaning (word learning based on sentence‐level constraints, SLCL). When combined, CSWL and SLCL potentially modulate each other's influence, revealing how word learners deal with multiple mechanisms simultaneously: Do they use all mechanisms? Prefer one? Is their strategy context dependent? Three experiments conducted with adult learners reveal that learners prioritize SLCL over CSWL. CSWL is applied in addition to SLCL only if SLCL is not perfectly disambiguating, thereby complementing or competing with it. These studies demonstrate the importance of investigating word‐learning mechanisms simultaneously, revealing important characteristics of their interaction in more naturalistic learning environments.     

The processing of consonants and vowels in reading: evidence from the fast priming paradigm

We assessed the early encoding of consonant and vowel information in the reading of English, using the fast priming paradigm. With 30-msec prime durations, gaze durations on target words were shorter when preceded by high-frequency consonant-same primes (which shared consonant information with the target word; e.g., lake-like) than when preceded by vowel-same primes (which shared vowel information with the target word; e.g., line-like), but there were no priming effects for low-frequency primes. With 45-msec prime durations, however, there was no effect of prime frequency and gaze durations on target words were shortened equally when they were preceded by consonant-same primes and vowelsame primes, as compared with control primes (e.g., late-like). The results suggest that the processing of consonants is more rapid than that of vowels, providing further evidence for the distinction between consonant and vowel processing in the reading of English.     

Gavagai Is as Gavagai Does: Learning Nouns and Verbs From Cross‐Situational Statistics

Learning to map words onto their referents is difficult, because there are multiple possibilities for forming these mappings. Cross‐situational learning studies have shown that word‐object mappings can be learned across multiple situations, as can verbs when presented in a syntactic context. However, these previous studies have presented either nouns or verbs in ambiguous contexts and thus bypass much of the complexity of multiple grammatical categories in speech. We show that noun word learning in adults is robust when objects are moving, and that verbs can also be learned from similar scenes without additional syntactic information. Furthermore, we show that both nouns and verbs can be acquired simultaneously, thus resolving category‐level as well as individual word‐level ambiguity. However, nouns were learned more quickly than verbs, and we discuss this in light of previous studies investigating the noun advantage in word learning.