The threshold of rule productivity in infants

Most learning theories agree that the productivity of a rule or a pattern relies on regular exemplars being dominant over exceptions; the threshold for productivity is, however, unclear; moreover, gradient productivity levels are assumed for different rules/patterns, regular or irregular. One theory by Yang, the Tolerance Principle (TP), specified a productivity threshold applicable to all rules, calculated by the numbers of total exemplars and exceptions of a rule; furthermore, rules are viewed as quantal, either productive or unproductive, with no gradient levels. We evaluated the threshold and gradience-quantalness questions by investigating infants’ generalization. In an implicit learning task, 14-month-olds heard exemplars of an artificial word-order rule and exceptions; their distributions were set closed to the TP-threshold (5.77) on both sides: 11 regular exemplars vs. 5 exceptions in Condition 1 (productiveness predicted), and 10 regular exemplars vs. 6 exceptions in Condition 2 (unproductiveness predicted). These predictions were pitted against those of the statistical majority threshold (50%), a common assumption which would predict generalization in both conditions (68.75, 62.5%). Infants were tested on the trained rule with new exemplars. Results revealed generalization in Condition 1, but not in Condition 2, supporting the TP-threshold, not the statistical majority threshold. Gradience-quantalness was assessed by combined analyses of Conditions 1-2 and previous experiments by Koulaguina and Shi. The training across the conditions contained gradually decreasing regular exemplars (100, 80, 68.75, 62.5, 50%) relative to exceptions. Results of test trials showed evidence for quantalness in infants (productive: 100, 80, 68.75%; unproductive: 62.5, 50%), with no gradient levels of productivity

Initial morphological learning in preverbal infants

a b s t r a c t How do children learn the internal structure of inflected words? We hypothesized that bound functional morphemes begin to be encoded at the preverbal stage, driven by their frequent occurrence with highly variable roots, and that infants in turn use these morphemes to interpret other words with the same inflections. Using a preferential looking procedure, we showed that French-learning 11-month-olds encoded the frequent French functor /e/, and perceived bare roots and their inflected variants as related forms. In another experiment an added training phase presented an artificial suffix co-occurring with many pseudo-roots. Infants learned the new suffix and used it to interpret novel affixed words that never occurred during the training. These findings demonstrate that initial learning of sub-lexical functors and morphological alternations is frequency-based, without relying on word meaning

Prosodic cues to syntatic structures in speech production

Children's initial syntactic acquisition tasks include finding clausal and phrasal units from continuous speech stream and assigning words to grammatical categories. This study inquires if prosodic cues exist in adult speech and mark syntactic units. Participants were Quebec-French speakers. In Experiment 1 participants read Determiner+Noun and Pronoun+Verb utterances. Determiners and pronouns were French words. Nouns and verbs were pseudo-words (e.g., mige, krale, vare) counterbalanced in their occurrences in the utterances. Their prosodic properties (duration, pitch, intensity) were measured. Results showed that the two categories did not differ in prosody: noun versus verb productions ofthese pseudo-words were equivalent. Experiment 2 tested whether larger utterances were produced with prosodic cues supporting different grammatical categories and phrasal groupings. The same pseudo-words were the final words (counterbalanced) in 1) [Determiner+Adjective+Noun] and 2)[[Determiner+Noun]+[Verb]] structures. The second word in both structures was felli. Results showed that the last word as nouns versus verbs differed significantly in duration, pitch and intensity. Moreover, the initial consonant of verb productions was longer, with a distinct preceding pause. The second word in (2) exhibited categorical and boundary cues, differing from the second word in (1) in duration, pitch and intensity. We suggest that these acoustic cues may help infants first parse larger utterances and then acquire the syntactic properties of phrases and words based on their distribution.DOI: 10.17074/2238-975X.2015v11n1p8

Mothers Reveal More of Their Vocal Identity When Talking to Infants

Voice timbre – the unique acoustic information in a voice by which its speaker can be recognized – is particularly critical in mother-infant interaction. Correct identification of vocal timbre is necessary in order for infants to recognize their mothers as familiar both before and after birth, providing a basis for social bonding between infant and mother. The exact mechanisms underlying infant voice recognition remain ambiguous and have predominantly been studied in terms of cognitive voice recognition abilities of the infant. Here, we show – for the first time – that caregivers actively maximize their chances of being correctly recognized by presenting more details of their vocal timbre through adjustments to their voices known as infant-directed speech (IDS) or baby talk, a vocal register which is wide-spread through most of the world’s cultures. Using acoustic modelling (k-means clustering of Mel Frequency Cepstral Coefficients) of IDS in comparison with adult-directed speech (ADS), we found in two cohorts of speakers - US English and Swiss German mothers - that voice timbre clusters of in IDS are significantly larger to comparable clusters in ADS. This effect leads to a more detailed representation of timbre in IDS with subsequent benefits for recognition. Critically, an automatic speaker identification using a Gaussian-mixture model based on Mel Frequency Cepstral Coefficients showed significantly better performance in two experiments when trained with IDS as opposed to ADS. We argue that IDS has evolved as part of an adaptive set of evolutionary strategies that serve to promote indexical signalling by caregivers to their offspring which thereby promote social bonding via voice and acquiring linguistic systems

Infants’ Recognition of Function Words in Continuous Speech

This study tests the hypothesis that function words are among the earliest word forms segmented by preverbal infants. In a visual fixation procedure, French-learning 8-month-old infants were familiarized to a function word, mes or ta. All infants were then tested with passages containing mes vs. ta. Looking times during the presentation of the two passage types were expected to differ if infants segmented the target functor. The results showed a significant interaction of passage type and sex. Although the direction of the looking preference is different for the two sexes, both groups showed a significant difference in listening times to the passage containing the target versus that containing the non-target. This suggests that both groups segmented the function words. The implications of functional elements for early lexical and syntactic acquisition are discussed

Development of abstract grammatical categorization in infants.

This study examined abstract syntactic categorization in infants, using the case of grammatical gender. Ninety-six French-learning 14-, 17-, 20-, and 30-month-olds completed the study. In a preferential looking procedure infants were tested on their generalized knowledge of grammatical gender involving pseudonouns and gender-marking determiners. The pseudonouns were controlled to contain no phonological or acoustical cues to gender. The determiner gender feature was the only information available. During familiarization, some pseudonouns followed a masculine determiner and others a feminine determiner. Test trials presented the same pseudonouns with different determiners in correct (consistent with familiarization gender pairing) versus incorrect gender agreement. Twenty-month-olds showed emerging knowledge of gender categorization and agreement. This knowledge was robust in 30-month-olds. These findings demonstrate that abstract, productive grammatical representations are present early in acquisition. When learning a language, children face many challenges. For example, they need to segment word forms from continuous speech, map meaning to word forms, and learn the grammatical properties of the words. To acquire syntax, children must learn that sentences are not simply composed of specific words, but rather are composed of abstract grammatical categories that can be combined to generate an infinite number of possible utterances. The acquisition of grammatical categories has been a major focus in child language research. In this study we examine abstract categorization of grammatical classes in infants, specifically grammatical gender in French. Theoretical models have been proposed to address the question of how infants acquire the system of grammatical categories. According to the semantic bootstrapping model (e.g., There had been a limited number of empirical studies on initial categorization. There is evidence that grammatical categorization begins at an early age. It has been shown that 1-to 3-day-old newborns can use prosodic and phonological information to categorize content words versus function words Correspondence concerning this article should be addressed to Rushen Shi, Département de psychologie, Université du Québec à Montréal, C.P. 8888, Succursale Centre-Ville, Montréal, QC, Canada H3C 3P8. Electronic mail may be sent to shi.rushen@ uqam.ca. © 2012 The Authors Child Development © 2012 Society for Research in Child Development, Inc. All rights reserved. 0009-3920/20120009-3920/ /xxxx-xxxx DOI: 10.11110009-3920/ /j.14670009-3920/ -8624.2012 Child Development, xxxx 2012, Volume 00, Number 0, Pages 1-13 languages, the two classes of words are distinct in their spoken forms: In comparison to content words, function words are universally minimized, both acoustically and phonologically (e.g., Shortly after their first birthday, infants begin to show knowledge about more specific categories, such as nouns or verbs. Mintz Evidence of noun categorization was also shown with 14-month-old French-learning infants in Grammatical category learning has also been investigated in artificial languages and unknown natural languages. The previous experimental findings indicate that grammatical categorization begins early in life, first with the global bifurcation of content words versus function words at birth. Categorization of nouns and verbs begins some time after 1 year of age. Initial grammatical categorization does not depend on semantic cues, as either the targets or all the stimuli in those studies were unknown words to the infants. The evidence thus far suggests that phonological cues along with distributional information support initial category learning. It appears that function words may constitute an efficient kind of distributional cue to initial categorization in infants. This is reasonable given that function words, which occupy crucial syntactic positions, are a small set of words that occur extremely frequently in natural languages. Function words and their distributional regularities with adjacent nonfunction words may therefore be particularly salient to infants. In an adult artificial language learning experiment, grammatical categorization performance was optimal when participants were presented with a small set of highly frequent words (i.e., resembling function words) relative to a large set of infrequent open-class words In this study we examined the development of the ability to use function words alone as the distributional anchor for categorizing content words. We addressed this question by testing French-learning infants' categorization of nouns according to grammatical gender. In French, nouns are divided into masculine and feminine categories. The determiner and the noun within a noun phrase agree in gender (e.g., la feminine maison feminine , "the house"; le masculine ballon masculine , "the ball"). Crucially, the assignment of gender for nouns is largely arbitrary semantically. For example, there is no particular reason why lit ("bed") is masculine and table ("table") is feminine. Hence, grammatical gender categorization cannot be acquired through semantics. Furthermore, nouns in French do not contain consistent phonological markings for gender, unlike in languages with clear gender morphophonological markings on the noun (e.g., Spanish, Russian). Although certain markings have been observed for some nouns in corpus and dictionary analyses, the markings were only weakly probabilistic (e.g., To unambiguously test if infants can categorize the gender of nouns on the sole basis of distributional cues related to determiners, we used novel nouns and strictly controlled their forms to avoid all possible cues to gender. In particular, we did an adult prestudy and an input analysis to ensure that the novel words that we constructed contained no phonological marking to gender. In addition, acoustic control was necessary to avoid potential distinct acoustic cues to gender in stimuli production. This consideration was based on the finding that English-speaking mothers produce noun-verb ambiguous words (e.g., talk, walk, kiss) differently, in that nouns tend to be longer in duration, higher in pitch, and more dynamic in pitch changes than verbs Grammatical genders of nouns are subcategories of the larger noun category. It is plausible for gender categorization to emerge after the higher order noun-verb categorization has been learned. Distributionally, nouns of different genders seem to exhibit a higher degree of overlap in sentences than nouns versus verbs. For example, nouns and verbs typically appear in distinct syntactic contexts, whereas nouns of masculine and feminine genders both occur in noun phrases, can precede the same auxiliaries and prepositions, and can follow the same gender-neutral determiners (plurals), numerals, and adjectives. Thus, gender categorization may be somewhat delayed in comparison to the categorization of the larger noun class. Indeed, gender knowledge has been observed in production (e.g., In short, we hypothesized that during the 2nd year of life infants can categorize grammatical gender classes of nouns based strictly on the distributional support of determiners. We tested infants' abstract ability to categorize gender, using Abstract Grammatical Categorization in Infants 3 pseudonouns and a purely syntactic task (i.e., with no semantic component). The use of pseudonouns was important for revealing whether the categorization was productive, that is, whether the knowledge involved abstract equivalent classes that were generalizable to novel instances. Our study thus differed from previous gender studies that used familiar nouns Experiment 1 Method Participants. Participants were sixteen 14-monthold (M age = 1;2;21; range = 1;2;6-1;3;2; 9 males, 7 females), sixteen 17-month-old (M age = 1;5;20; range = 1;5;8-1;5;30; 6 males, 10 females), sixteen 20-month-old (M age = 1;8;24; range = 1;8;1-1;9;11; 11 males, 5 females), and sixteen 30-month-old (M age = 2;6;21; range = 2;6;3-2;7;14; 6 males, 10 females) monolingual French-learning infants. An additional eighteen infants were tested but were not included in the analyses because of fussiness (eight), parental interference (three), experimental error (three), equipment failure (one), and ceiling looking (three, i.e., never turned fixation away from the display monitor throughout the entire experiment). Stimuli. The stimuli consisted of pseudonouns and French determiners. There were several reasons for the use of pseudonouns in this study. First, using pseudonouns allowed us to examine infants' capacity to assign novel words to abstract gender categories. Second, it allowed us to eliminate potential phonological or acoustical biases for gender. Finally, using pseudonouns allowed us to control for infants' prior exposure to the stimuli, as the stimuli in our experiment were equally unfamiliar to all infants. Four pseudonouns were used in the stimuli set: mouveille, ravole, cagère, and gombale. They were chosen from a prestudy with French-speaking adults. We designed the prestudy to determine which pseudonouns were equally probable in both masculine and feminine genders. The goal was therefore to neutralize any phonological cues to gender in the pseudonouns for our experiments with infants. In this prestudy, 10 participants were orally presented with 26 pseudowords that we constructed. Following the presentation of each pseudoword, the participant had to orally create a sentence using the pseudoword as a noun. Next, he or she was asked to decide whether the pseudoword was noun-like in French, and whether it was a typical-sounding noun. As determiners generally occur in noun phrases in French, the participants spontaneously produced a determiner before the pseudoword in every sentence. Therefore, we were able to implicitly induce gender production from the adults for each pseudoword. The rational is that if a pseudoword is phonologically biased toward one of the two genders, it should be produced more often with a determiner of that gender, whereas if a pseudoword is not phonologically gender biased, it should be equally likely to be produced with a determiner of either gender. The four pseudoword listed above were produced with comparable numbers of masculine versus feminine determiners across participants (mouveille: 40% masculine, 60% feminine; ravole: 50% masculine, 50% feminine; cagère: 50% masculine, 50% feminine; gombale: 60% masculine, 40% feminine). They were also judged as typical-sounding nouns in French. In addition, a corpus analysis of infant-directed speech in French was conducted to ensure that the specific endings of the four pseudonouns contained no phonological marking to gender in children's input. We counted the frequencies of endings in all masculine and feminine nouns in sample transcripts from several corpora of the CHILDES database We then constructed noun phrases, each containing a French determiner: un ("a," masculine), une ("a," feminine), le ("the," masculine), and la ("the," feminine). The following phrases were used as the familiarization stimuli: un mouveille, une mouveille, un ravole, une ravole, un gombale, une gombale, un cagère, une cagère. The stimuli for the test phase were as follows: le mouveille, la mouveille, le ravole, la ravole, le gombale, la gombale, le cagère, la cagère. The auditory materials were recorded in an acoustical chamber by a native French female speaker in the infant-directed speech style. The stimuli were recorded using a digital audio recorder Sound Device 702T (44 kHz sampling frequency, 24 bits bit rate) and then transferred digital-to-digital to a computer. The four pseudonouns were each recorded multiple times in isolation and in noun phrases with each of the four determiners (un, une, le, and la). The pseudonouns were produced with three different intonations (flat, rising, and falling). In total, three tokens of every noun phrase (one for each intonation) were selected. To eliminate any possible acoustic or prosodic cues to gender in the pseudonouns, the final stimuli were created within Praat software (version 4.5.26; The visual stimulus file consisted of a cartoon puppet standing in the center of the screen. We synchronized the mouth movements of the puppet to match the auditory stimuli so that the puppet "spoke" the noun phrases. While speaking, the puppet also moved her hands, head, and body. The visual stimuli were created using Adobe ® Flash ® CS3 Professional software (Adobe Systems Incorporated, San Jose, CA) and exported in a QuickTime format with a 30 fps frame rate and a resolution of 1360 9 768 pixels. The purpose of this animation was to make the task interesting for the infants. Design. The experiment consisted of a familiarization phase and a test phase. During familiarization, infants were presented with noun phrases in which the four pseudonouns described above were paired with two of the four determiners (i.e., unmasculine, une-feminine). Two of the four pseudonouns were preceded by the masculine determiner un (e.g., un mouveille, un ravole) and two were preceded by the feminine determiner une (e.g., une gombale, une cagère). The grammatical gender pairings were counterbalanced across infants, forming two different familiarization conditions (see the familiarization stimuli for Group A vs. Group B in In the test phase, the same four pseudonouns were again presented in noun phrases, this time paired with the other two determiners (le-masculine, la-feminine) that were not used during familiarization. There were two trial types: grammatical and ungrammatical trials. In the grammatical trials, two pseudonouns from familiarization (one that had been paired with the masculine determiner un and one that had been paired with the feminine determiner une) were now paired with the nonfamiliarized determiners that were gender consistent with the familiarization (e.g., le mouveille, la gombale). In the ungrammatical trials, the remaining Abstract Grammatical Categorization in Infants 5 two pseudonouns were paired with the nonfamiliarized determiners that were inconsistent in gender with the familiarization (e.g., le cagère, la ravole). Tokens of the noun phrases of each trial type were presented quasi-randomly to ensure variability. In particular, any given noun phrase never occurred more than twice consecutively. The same variability applied for the intonations of the stimuli. During each test trial the interphrase interval was 700 ms. In total, the test phase consisted of 10 trials, with a maximum length of 15.2 s for each trial. Grammatical and ungrammatical trials (five trials each) were presented in alternation. The type of the first trial (grammatical or ungrammatical) was counterbalanced across participants. The specific pseudonouns used as grammatical and ungrammatical stimuli were also counterbalanced across participants (as shown in Procedure. The participants were tested individually in a preferential looking paradigm. Upon arrival, the caregiver(s) were informed of the procedure and were asked not to interfere during the experiment (e.g., talking to the child or pointing at the screen). Then, the caregiver and the infant were led to a double-walled IAC acoustical chamber (interior dimension 9 ft 8 in. 9 9 ft 8 in.). Here, the infant sat on the caregiver's lap approximately 1.5 m in front of a 42-in. LG TV monitor. The caregiver listened to masking music through nois

PAPER French-learning toddlers use gender information on determiners during word recognition

Abstract In gender-marking languages, the gender of the noun determines the form of the preceding article

Recognition and representation of function words in English-learning infants

We examined infants' recognition of functors and the accuracy of the representations that infants construct of the perceived word forms. Auditory stimuli were “Functor + Content Word” versus “Nonsense Functor + Content Word” sequences. Eight-, 11-, and 13-month-old infants heard both real functors and matched nonsense functors (prosodically analogous to their real counterparts but containing a segmental change). Results reveal that 13-month-olds recognized functors with attention to segmental detail. Eight-month-olds did not distinguish real versus nonsense functors. The performance of 11-month-olds fell in between that of the older and younger groups, consistent with an emerging recognition of real functors. The three age groups exhibited a clear developmental trend. We propose that in the earliest stages of vocabulary acquisition, function elements receive no segmentally detailed representations, but such representations are gradually constructed so that once vocabulary growth starts in earnest, fully specified functor representations are in place to support it