The arbitrariness of the sign: learning advantages from the structure of the vocabulary

Recent research has demonstrated that systematic mappings between phonological word forms and their meanings can facilitate language learning (e.g., in the form of sound symbolism or cues to grammatical categories). Yet, paradoxically from a learning viewpoint, most words have an arbitrary form-meaning mapping. We hypothesized that this paradox may reflect a division of labor between 2 different language learning functions: arbitrariness facilitates learning specific word meanings and systematicity facilitates learning to group words into categories. In a series of computational investigations and artificial language learning studies, we varied the extent to which the language was arbitrary or systematic. For both the simulations and the behavioral studies, we found that the optimal structure of the vocabulary for learning incorporated this division of labor. Corpus analyses of English and French indicate that these predicted patterns are also found in natural languages.     

Sound-symbolism: A Piece in the Puzzle of Word Learning

Sound-symbolism is the idea that the relationship between word sounds and word meaning is not arbitrary for all words, but rather that there are subsets of words in the world’s languages for which sounds and their symbols have some degree of correspondence. The present research investigates sound-symbolism as a possible route to the learning of an unknown word’s meaning. Three studies compared the guesses that adult participants made regarding the potential meanings of sound-symbolic and non-sound symbolic obsolete words. In each study, participants were able to generate better definitions for sound-symbolic words when compared to non-sound symbolic words. Participants were also more likely to recognize the meanings of sound symbolic words. The superior performance on sound-symbolic words held even when definitions generated on the basis of sound association were eliminated. It is concluded that sound symbolism is a word property that influences word learning.     

Japanese Sound‐Symbolism Facilitates Word Learning in English‐Speaking Children

Sound‐symbolism is the nonarbitrary link between the sound and meaning of a word. Japanese‐speaking children performed better in a verb generalization task when they were taught novel sound‐symbolic verbs, created based on existing Japanese sound‐symbolic words, than novel nonsound‐symbolic verbs ( Imai, Kita, Nagumo, & Okada, 2008 ). A question remained as to whether the Japanese children had picked up regularities in the Japanese sound‐symbolic lexicon or were sensitive to universal sound‐symbolism. The present study aimed to provide support for the latter. In a verb generalization task, English‐speaking 3‐year‐olds were taught novel sound‐symbolic verbs, created based on Japanese sound‐symbolism, or novel nonsound‐symbolic verbs. English‐speaking children performed better with the sound‐symbolic verbs, just like Japanese‐speaking children. We concluded that children are sensitive to universal sound‐symbolism and can utilize it in word learning and generalization, regardless of their native language.     

(Non)words, (non)words, (non)words: evidence for a protolexicon during the first year of life

Previous research with artificial language learning paradigms has shown that infants are sensitive to statistical cues to word boundaries (Saffran, Aslin & Newport, 1996) and that they can use these cues to extract word‐like units (Saffran, 2001). However, it is unknown whether infants use statistical information to construct a receptive lexicon when acquiring their native language. In order to investigate this issue, we rely on the fact that besides real words a statistical algorithm extracts sound sequences that are highly frequent in infant‐directed speech but constitute nonwords. In three experiments, we use a preferential listening paradigm to test French‐learning 11‐month‐old infants' recognition of highly frequent disyllabic sequences from their native language. In Experiments 1 and 2, we use nonword stimuli and find that infants listen longer to high‐frequency than to low‐frequency sequences. In Experiment 3, we compare high‐frequency nonwords to real words in the same frequency range, and find that infants show no preference. Thus, at 11 months, French‐learning infants recognize highly frequent sound sequences from their native language and fail to differentiate between words and nonwords among these sequences. These results are evidence that they have used statistical information to extract word candidates from their input and stored them in a ‘protolexicon’, containing both words and nonwords.     

语音象征的产生机制：基于敏感期的先天后天作用模型

Bouba-Kiki效应(简称BK效应)指语音和形状特征之间的映射关系。针对BK效应的产生机制, 先天论和后天论之间争论激烈。先天论的观点认为人们对语音象征的敏感性是出生时便存在的一种语言机制。而后天论的观点则强调语音象征是语言经验的产物。上述理论均获得大量研究证据的支持, 且均无法完全否定对方。这表明, 上述理论可能均未完整揭示语音象征的产生机制。鉴于此, 针对BK效应的产生机制, 梳理先天论与后天论的支持证据, 并率先提出语言相关的BK效应敏感期假设。同时, 梳理了支持BK效应敏感期的初步研究证据及可能的影响因素。进而, 以语言相关的BK效应敏感期假设为基础, 提出语音象征产生的先天后天相互作用模型, 以整合以往研究中的矛盾。最后, 展望了语音象征的未来研究进展和方向。     

Class matters: 12‐month‐olds’ word–object associations privilege content over function words

A fundamental step in learning words is the development of an association between a sound pattern and an element in the environment. Here we explore the nature of this associative ability in 12‐month‐olds, examining whether it is constrained to privilege particular word forms over others. Forty‐eight infants were presented with sets of novel English content‐like word–object pairings (e.g. fep) or novel English function‐like word–object (e.g. iv) pairings until they habituated. Results indicated that infants associated novel content‐like words, but not the novel function‐like words, with novel objects. These results demonstrate that the mechanism with which basic word–object associations are formed is remarkably sophisticated by the onset of productive language. That is, mere associative pairings are not sufficient to form mappings. Rather the system requires well‐formed noun‐like words to co‐occur with objects in order for the linkages to arise.     

Consolidation of novel word learning in native English-speaking adults

Sleep has been shown to improve the retention of newly learned words. However, most methodologies have used artificial or foreign language stimuli, with learning limited to word/novel word or word/image pairs. Such stimuli differ from many word-learning scenarios in which definition strings are learned with novel words. Thus, we examined sleep's benefit on learning new words within a native language by using very low-frequency words. Participants learned 45 low-frequency English words and, at subsequent recall, attempted to recall the words when given the corresponding definitions. Participants either learned in the morning with recall in the evening (wake group), or learned in the evening with recall the following morning (sleep group). Performance change across the delay was significantly better in the sleep than the wake group. Additionally, the Levenshtein distance, a measure of correctness of the typed word compared with the target word, became significantly worse following wake, whereas sleep protected correctness of recall. Polysomnographic data from a subsample of participants suggested that rapid eye movement (REM) sleep may be particularly important for this benefit. These results lend further support for sleep's function on semantic learning even for word/definition pairs within a native language.     

Word Meanings Evolve to Selectively Preserve Distinctions on Salient Dimensions

Words refer to objects in the world, but this correspondence is not one‐to‐one: Each word has a range of referents that share features on some dimensions but differ on others. This property of language is called underspecification. Parts of the lexicon have characteristic patterns of underspecification; for example, artifact nouns tend to specify shape, but not color, whereas substance nouns specify material but not shape. These regularities in the lexicon enable learners to generalize new words appropriately. How does the lexicon come to have these helpful regularities? We test the hypothesis that systematic backgrounding of some dimensions during learning and use causes language to gradually change, over repeated episodes of transmission, to produce a lexicon with strong patterns of underspecification across these less salient dimensions. This offers a cultural evolutionary mechanism linking individual word learning and generalization to the origin of regularities in the lexicon that help learners generalize words appropriately.     

The Specificity of Sound Symbolic Correspondences in Spoken Language

Although language has long been regarded as a primarily arbitrary system, sound symbolism, or non‐arbitrary correspondences between the sound of a word and its meaning, also exists in natural language. Previous research suggests that listeners are sensitive to sound symbolism. However, little is known about the specificity of these mappings. This study investigated whether sound symbolic properties correspond to specific meanings, or whether these properties generalize across semantic dimensions. In three experiments, native English‐speaking adults heard sound symbolic foreign words for dimensional adjective pairs (big/small, round/pointy, fast/slow, moving/still) and for each foreign word, selected a translation among English antonyms that either matched or mismatched with the correct meaning dimension. Listeners agreed more reliably on the English translation for matched relative to mismatched dimensions, though reliable cross‐dimensional mappings did occur. These findings suggest that although sound symbolic properties generalize to meanings that may share overlapping semantic features, sound symbolic mappings offer semantic specificity.     

Sound symbolism facilitates early verb learning

Some words are sound-symbolic in that they involve a non-arbitrary relationship between sound and meaning. Here, we report that 25-month-old children are sensitive to cross-linguistically valid sound-symbolic matches in the domain of action and that this sound symbolism facilitates verb learning in young children. We constructed a set of novel sound-symbolic verbs whose sounds were judged to match certain actions better than others, as confirmed by adult Japanese- as well as English speakers, and by 2- and 3-year-old Japanese-speaking children. These sound-symbolic verbs, together with other novel non-sound-symbolic verbs, were used in a verb learning task with 3-year-old Japanese children. In line with the previous literature, 3-year-olds could not generalize the meaning of novel non-sound-symbolic verbs on the basis of the sameness of action. However, 3-year-olds could correctly generalize the meaning of novel sound-symbolic verbs. These results suggest that iconic scaffolding by means of sound symbolism plays an important role in early verb learning.     

Wordform Similarity Increases With Semantic Similarity: An Analysis of 100 Languages

Although the mapping between form and meaning is often regarded as arbitrary, there are in fact well‐known constraints on words which are the result of functional pressures associated with language use and its acquisition. In particular, languages have been shown to encode meaning distinctions in their sound properties, which may be important for language learning. Here, we investigate the relationship between semantic distance and phonological distance in the large‐scale structure of the lexicon. We show evidence in 100 languages from a diverse array of language families that more semantically similar word pairs are also more phonologically similar. This suggests that there is an important statistical trend for lexicons to have semantically similar words be phonologically similar as well, possibly for functional reasons associated with language learning.     

Twelve-month-olds privilege words over other linguistic sounds in an associative learning task

We examined whether 12-month-old infants privilege words over other linguistic stimuli in an associative learning task. Sixty-four infants were presented with sets of either word–object, communicative sound–object, or consonantal sound–object pairings until they habituated. They were then tested on a ‘switch’ in the sound to determine whether they were able to associate the word and/or sound with the novel objects. Infants associated words, but not communicative sounds or consonantal sounds, with novel objects. The results demonstrate that infants exhibit a preference for words over other linguistic stimuli in an associative word learning task. This suggests that by 12 months of age, infants have developed knowledge about the nature of an appropriate sound form for an object label and will privilege this form as an object label.     

The evocative power of words: activation of concepts by verbal and nonverbal means

A major part of learning a language is learning to map spoken words onto objects in the environment. An open question is what are the consequences of this learning for cognition and perception? Here, we present a series of experiments that examine effects of verbal labels on the activation of conceptual information as measured through picture verification tasks. We find that verbal cues, such as the word "cat," lead to faster and more accurate verification of congruent objects and rejection of incongruent objects than do either nonverbal cues, such as the sound of a cat meowing, or words that do not directly refer to the object, such as the word "meowing." This label advantage does not arise from verbal labels being more familiar or easier to process than other cues, and it does extends to newly learned labels and sounds. Despite having equivalent facility in learning associations between novel objects and labels or sounds, conceptual information is activated more effectively through verbal means than through nonverbal means. Thus, rather than simply accessing nonverbal concepts, language activates aspects of a conceptual representation in a particularly effective way. We offer preliminary support that representations activated via verbal means are more categorical and show greater consistency between subjects. These results inform the understanding of how human cognition is shaped by language and hint at effects that different patterns of naming can have on conceptual structure.     

The role of embodied intention in early lexical acquisition

We examine the influence of inferring interlocutors' referential intentions from their body movements at the early stage of lexical acquisition. By testing human participants and comparing their performances in different learning conditions, we find that those embodied intentions facilitate both word discovery and word-meaning association. In light of empirical findings, the main part of this article presents a computational model that can identify the sound patterns of individual words from continuous speech, using nonlinguistic contextual information, and employ body movements as deictic references to discover word-meaning associations. To our knowledge, this work is the first model of word learning that not only learns lexical items from raw multisensory signals to closely resemble infant language development from natural environments, but also explores the computational role of social cognitive skills in lexical acquisition.     

Phonation Types Matter in Sound Symbolism

Sound symbolism is a non-arbitrary correspondence between sound and meaning. The majority of studies on sound symbolism have focused on consonants and vowels, and the sound-symbolic properties of suprasegmentals, particularly phonation types, have been largely neglected. This study examines the size and shape symbolism of four phonation types: modal and creaky voices, falsetto, and whisper. Japanese speakers heard 12 novel words (e.g., /íbi/, /ápa/) pronounced with the four types of phonation and rated the size and roundedness/pointedness each of the 48 stimuli seemed to represent on seven-point scales. The results showed that phonation types as well as consonantal and vocalic features influenced the ratings. Creaky voice was associated with larger and more pointed images than modal voice, which was in turn associated with larger and more pointed images than whisper. Falsetto was also associated with roundedness but not with smallness. These results shed new light on the acoustic approaches to sound symbolism and suggest the significance of phonation types and other suprasegmental features in the phenomenon.     

Infant speech perception bootstraps word learning

By their first birthday, infants can understand many spoken words. Research in cognitive development has long focused on the conceptual changes that accompany word learning, but learning new words also entails perceptual sophistication. Several developmental steps are required as infants learn to segment, identify and represent the phonetic forms of spoken words, and map those word forms to different concepts. We review recent research on how infants' perceptual systems unfold in the service of word learning, from initial sensitivity for speech to the learning of language-specific sound patterns. Building on a recent theoretical framework and emerging new methodologies, we show how speech perception is crucial for word learning, and suggest that it bootstraps the development of a separate but parallel phonological system that links sound to meaning.     

Sound to meaning correspondences facilitate word learning

A fundamental assumption regarding spoken language is that the relationship between sound and meaning is essentially arbitrary. The present investigation questioned this arbitrariness assumption by examining the influence of potential non-arbitrary mappings between sound and meaning on word learning in adults. Native English-speaking monolinguals learned meanings for Japanese words in a vocabulary-learning task. Spoken Japanese words were paired with English meanings that: (1) matched the actual meaning of the Japanese word (e.g., “hayai” paired with fast); (2) were antonyms for the actual meaning (e.g., “hayai” paired with slow); or (3) were randomly selected from the set of antonyms (e.g., “hayai” paired with blunt). The results showed that participants learned the actual English equivalents and antonyms for Japanese words more accurately and responded faster than when learning randomly paired meanings. These findings suggest that natural languages contain non-arbitrary links between sound structure and meaning and further, that learners are sensitive to these non-arbitrary relationships within spoken language.     

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.     

Modality exclusivity norms for 400 nouns: The relationship between perceptual experience and surface word form

We present modality exclusivity norms for 400 randomly selected noun concepts, for which participants provided perceptual strength ratings across five sensory modalities (i.e., hearing, taste, touch, smell, and vision). A comparison with previous norms showed that noun concepts are more multimodal than adjective concepts, as nouns tend to subsume multiple adjectival property concepts (e.g., perceptual experience of the concept baby involves auditory, haptic, olfactory, and visual properties, and hence leads to multimodal perceptual strength). To show the value of these norms, we then used them to test a prediction of the sound symbolism hypothesis: Analysis revealed a systematic relationship between strength of perceptual experience in the referent concept and surface word form, such that distinctive perceptual experience tends to attract distinctive lexical labels. In other words, modality-specific norms of perceptual strength are useful for exploring not just the nature of grounded concepts, but also the nature of form–meaning relationships. These norms will be of benefit to those interested in the representational nature of concepts, the roles of perceptual information in word processing and in grounded cognition more generally, and the relationship between form and meaning in language development and evolution.     

注意和记忆对孤独症儿童词汇发展滞后的影响

孤独症语言障碍的表现之一是词汇发展滞后, 可能与其注意和记忆损伤有关。当前研究结果表明, 孤独症儿童在学习词汇时难以利用社会注意提供的有效信息, 且其注意易受到无关刺激干扰, 这可能导致其形成的物体-词汇的联结不稳定, 影响其进一步将这种联结整合到心理词典并保存在记忆中。未来研究应探究联合注意影响孤独症儿童词汇学习的发展轨迹和机制, 儿童的词汇知识对其词汇记忆的影响, 并关注自然场景中孤独症儿童的词汇学习过程和个体差异。