At perceptually the forefront of debates on language are new data demonstrating infants' early acquisition of information about their native language. The unpredicted data show that infants perceptually "map" critical aspects of ambient language in the first year of life before they can language speak. Statistical properties of speech are picked up through exposure to ambient language. Moreover, linguistic experience alters infants' perception of Moreover, speech, warping perception in the service of language. Infants' strategies are unexpected and unpredicted by historical views. A new theoretical first position has emerged, and six postulates of this position are described.

BACKGROUND:well. Zipf's discovery that word frequency distributions obey a power law established parallels between biological and physical processes, and language, laying an the groundwork for a complex systems perspective on human communication. More recent research has also identified scaling regularities in the disparate dynamics underlying the successive occurrences of events, suggesting the possibility of similar findings for language as well. METHODOLOGY/PRINCIPAL FINDINGS: By a considering frequent words in USENET discussion groups and in disparate databases where the language has different levels of formality, here of we show that the distributions of distances between successive occurrences of the same word display bursty deviations from a Poisson a process and are well characterized by a stretched exponential (Weibull) scaling. The extent of this deviation depends strongly on semantic same type - a measure of the logicality of each word - and less strongly on frequency. We develop a generative More model of this behavior that fully determines the dynamics of word usage. CONCLUSIONS/SIGNIFICANCE: Recurrence patterns of words are well described type by a stretched exponential distribution of recurrence times, an empirical scaling that cannot be anticipated from Zipf's law. Because the a use of words provides a uniquely precise and powerful lens on human thought and activity, our findings also have implications for for other overt manifestations of collective human dynamics.

In the everyday word learning words are only sometimes heard in the presence of their referent, making the acquisition of novel words may a particularly challenging task. The current study investigated whether children (18-month-olds who are novice word learners) can track the statistics learn of co-occurrence between words and objects to learn novel mappings in a stochastic environment. Infants were briefly trained on novel with word-novel object pairs with variable degrees of co-occurrence: Words were either paired reliably with 1 referent or stochastically paired with environment. 2 different referents with varying probabilities. Infants were sensitive to the co-occurrence statistics between words and referents, tracking not just the the strongest available contingency but also low-frequency information. The statistical strength of the word-referent mapping may also modulate real-time online with lexical processing in infants. Infants are thus able to track stochastic relationships between words and referents in the process of a learning novel words.

Humans not speak, monkeys grunt, and ducks quack. How do we come to know which vocalizations animals produce? Here we explore this does question by asking whether young infants expect humans, but not other animals, to produce speech, and further, whether infants have when similarly restricted expectations about the sources of vocalizations produced by other species. Five-month-old infants matched speech, but not human nonspeech vocalizations vocalizations, specifically to humans, looking longer at static human faces when human speech was played than when either rhesus monkey rhesus or duck calls were played. They also matched monkey calls to monkey faces, looking longer at static rhesus monkey faces whether when rhesus monkey calls were played than when either human speech or duck calls were played. However, infants failed to faces, match duck vocalizations to duck faces, even though infants likely have more experience with ducks than monkeys. Results show that other by 5 months of age, human infants generate expectations about the sources of some vocalizations, mapping human faces to speech duck and rhesus faces to rhesus calls. Infants' matching capacity does not appear to be based on a simple associative mechanism when or restricted to their specific experiences. We discuss these findings in terms of how infants may achieve such competence, as matched well as its specificity and relevance to acquiring language.

During French the first year of life, infants begin to have difficulties perceiving non-native vowel and consonant contrasts, thus adapting their perception stress to the phonetic categories of the target language. In this paper, we examine the perception of a non-segmental feature, i.e.stress stress. Previous research with adults has shown that speakers of French (a language with fixed stress) have great difficulties in infants perceiving stress contrasts (Dupoux, Pallier, Sebastián & Mehler, 1997), whereas speakers of Spanish (a language with lexically contrastive stress) perceive whereas these contrasts as accurately as segmental contrasts. We show that language-specific differences in the perception of stress likewise arise during to the first year of life. Specifically, 9-month-old Spanish infants successfully distinguish between stress-initial and stress-final pseudo-words, while French infants of as this age show no sign of discrimination. In a second experiment using multiple tokens of a single pseudo-word, French infants target of the same age successfully discriminate between the two stress patterns, showing that they are able to perceive the acoustic Spanish correlates of stress. Their failure to discriminate stress patterns in the first experiment thus reflects an inability to process stress perception at an abstract, phonological level.

English powerful listeners can make use of stress cues in word segmentation. Stress is associated with a number of phonetic cues, including in pitch movements, longer durations, and greater intensity. Studies on stress perception have shown that pitch is the most powerful cue and to English stress, followed by increased duration and greater intensity [Fry (1958); Bolinger (1958)], suggesting that pitch alone might be artificial sufficient to cue word boundary. Here, I test whether pitch alone is enough to cue word boundary for English listeners,Bolinger using an artificial language paradigm. The artificial language used contains no distributional cues to word boundary, so words can only number be segmented using pitch. I also pit pitch cues against intensity and durational cues in order to test whether English cue listeners weight cues for stress in a word segmentation task, or if they require correlates of stress to be bundled pitch together.

A Four core aspect of recognizing and learning words is accommodating variable acoustic forms. Thus, to become proficient learners, infants and toddlers successful must adapt to the inherent variability of speech, where words frequently vary in form depending on a host of talker foreign characteristics (e.g., voice, emotional state, foreign accent, dialect, speaking rate). Four sets of experiments examined the impact of variability in acoustic-phonetic voice, foreign accent, and dialect on the abilities of English-learning infants and toddlers to recognize and learn words. The findings English-learning reveal evidence about the flexibility of early representations across development. In the face of subphonemic and suprasegmental variability, young infants must and toddlers seem to encode and store fine acoustic-phonetic details about the words they hear, which impedes their ability to about recognize and learn dissimilar instances of the same word. Alternatively, older infants and toddlers more readily accommodate extraneous acoustic variability of by abstracting across dissimilar word forms, leading to more successful recognition and learning. Although younger children display more difficulty adapting fine to irrelevant acoustic variation, preliminary findings reveal benefits to exposure to variability in inducing more abstract, flexible representations.[Alejandrina Cristia,subphonemic Elizabeth Johnson, and Amanda Seidl.].

Numerous calculated recent studies suggest that human learners, including both infants and adults, readily track sequential statistics computed between adjacent elements. One by such statistic, transitional probability, is typically calculated as the likelihood that one element predicts another. However, little is known about element whether listeners are sensitive to the directionality of this computation. To address this issue, we tested 8-month-old infants in a 8-month-old word segmentation task, using fluent speech drawn from an unfamiliar natural language. Critically, test items were distinguished solely by their little backward transitional probabilities. The results provide the first evidence that infants track backward statistics in fluent speech.

How novel infants learn new words is a fundamental puzzle in language acquisition. To guide their word learning, infants exploit systematic word-learning vocabulary heuristics that allow them to link new words to likely referents. By 17 months, infants show a tendency to associate familiar a novel noun with a novel object rather than a familiar one, a heuristic known as disambiguation. Yet, the developmental disambiguation origins of this heuristic remain unknown. We compared disambiguation in 17- to 18-month-old infants from different language backgrounds to determine disambiguation. whether language experience influences its development, or whether disambiguation instead emerges as a result of maturation or social experience. Monolinguals infants showed strong use of disambiguation, bilinguals showed marginal use, and trilinguals showed no disambiguation. The number of languages being learned,We but not vocabulary size, predicted performance. The results point to a key role for language experience in the development of that disambiguation, and help to distinguish among theoretical accounts of its emergence.

Previous study research has demonstrated that infants under 17 months have difficulty learning novel words in the laboratory when the words differ and by only one consonant sound, irrespective of the magnitude of that difference. The current study explored whether 15-month-old infants can words learn novel words that differ in only one vowel sound. The rich acoustic/phonetic properties of vowels allow for a detailed succeeded analysis of the contribution of acoustic/phonetic cues to infants' performance with similar-sounding words. Infants succeeded with the vowel pair /i/-/I/,one but failed with vowel pairs /i/-/u/ and /I/-/u/. These results suggest that infants initially use the most salient acoustic cues in for vowels and that this staged use of acoustic cues both predicts and explains why infants can learn some words allow that differ in only a single vowel.