Rory A. DePaolis

The influence of babbling patterns on the processing of speech.

This study compared the preference of 27 British English- and 26 Welsh-learning infants for nonwords featuring consonants that occur with equal frequency in the input but that are produced either with equal frequency (Welsh) or with differing frequency (British English) in infant vocalizations. For the English infants a significant difference in looking times was related to the extent of production of the nonword consonants. The Welsh infants, who showed no production preference for either consonant, exhibited no such influence of production patterns on their response to the nonwords. The results are consistent with a previous study that suggested that pre-linguistic babbling helps shape the processing of input speech, serving as an articulatory filter that selectively makes production patterns more salient in the input.

The Relationship Between Infants’ Production Experience and Their Processing of Speech

The early relationship between childrens emerging articulatory abilities and their capacity to process speech input was investigated, following recent studies with English-learning infants. Twenty-six monolingual Italian-learning infants were tested at 6 months (no consistent and stable use of consonants, or vocal motor schemes [VMS]) and at the age at which they displayed use of at least one VMS. Perceptual testing was based on lists of nonwords containing one of three categories of sounds each: produced by infant (own VMS), not yet produced but typical of that age (other VMS), or not typically produced by infants at that age (non-VMS). In addition, size of expressive lexicon at 12 months and 18 months was assessed using an Italian version of the MacArthur-Bates Communicative Development Inventory (CDI). The results confirmed a relation between infant preverbal production and attentional response to VMS and also between age at first VMS and 12-month vocabulary. Maternal input is shown not to be a specific determinant of individual infant production preferences. A comparison between the English and Italian experimental findings shows a stronger attentional response to VMS in isolated words as compared to sentences. These results confirm the existence of an interaction between perception and production that helps to shape the way that language develops.

Prosody in production at the onset of word use: A cross-linguistic study

Abstract An investigation of the acoustic correlates of prosody in infant disyllabic vocalizations was undertaken on the basis of data from 10 each of American- and Finnish- and five each of French- and Welsh-learning infants at the onset of word use (10–18 months). The 639 disyllables were analyzed acoustically for duration, intensity and fundamental frequency ( f 0). The infants differed in their production patterns with regard to all three acoustic cues, although they agreed in exhibiting high variability in the production of intensity and f 0. Infants exposed to each of the four languages showed evidence of final syllable lengthening and the production of both first- and second-syllable-stressed or accented disyllables. However, Finnish and Welsh infants produced proportionally more trochaic and iambic patterns, respectively. The use of acoustic prosodic cues at the onset of word use is argued to reflect a combination of biological predispositions and response to prosodic cues that show consistency in the input signal, while a more complete integration of prosody and segmental features seems to require more lexical knowledge or experience.

British English infants segment words only with exaggerated infant-directed speech stimuli

The word segmentation paradigm originally designed by Jusczyk and Aslin (1995) has been widely used to examine how infants from the age of 7.5 months can extract novel words from continuous speech. Here we report a series of 13 studies conducted independently in two British laboratories, showing that British English-learning infants aged 8-10.5 months fail to show evidence of word segmentation when tested in this paradigm. In only one study did we find evidence of word segmentation at 10.5 months, when we used an exaggerated infant-directed speech style. We discuss the impact of variations in infant-directed style within and across languages in the course of language acquisition.

When do infants begin recognizing familiar words in sentences

Previous studies have shown that by 11 but not by 10 months infants recognize words that have become familiar from everyday life independently of the experimental setting. This study explored the ability of 10-, 11-, and 12-month-old infants to recognize familiar words in sentential context, without experimental training. The headturn preference procedure was used to contrast passages containing words likely to be familiar to the infants with passages containing words unlikely to have been previously heard. Two stimulus words were inserted near the beginning and end of each of a set of simple sentence frames. The ability to recognize the familiar words within sentences emerged only at 12 months of age. The contrast between segmentation abilities as they emerge as a result of everyday exposure to language, as assessed here, and those abilities as measured in studies in which words are experimentally trained is discussed in terms of memory-based mechanisms.

Making Sense of Infant Familiarity and Novelty Responses to Words at Lexical Onset.

This study suggests that familiarity and novelty preferences in infant experimental tasks can in some instances be interpreted together as a single indicator of language advance. We provide evidence to support this idea based on our use of the auditory headturn preference paradigm to record responses to words likely to be either familiar or unfamiliar to infants. Fifty-nine 10-month-old infants were tested. The task elicited mixed preferences: familiarity (longer average looks to the words likely to be familiar to the infants), novelty (longer average looks to the words likely to be unfamiliar) and no-preference (similar-length of looks to both type of words). The infants who exhibited either a familiarity or a novelty response were more advanced on independent indices of phonetic advance than the infants who showed no preference. In addition, infants exhibiting novelty responses were more lexically advanced than either the infants who exhibited familiarity or those who showed no-preference. The results provide partial support for Hunter and Ames’ (1988) developmental model of attention in infancy and suggest caution when interpreting studies indexed to chronological age.

Manual Activity and Onset of First Words in Babies Exposed and Not Exposed to Baby Signing

Support for baby signing (BS) with hearing infants tends to converge toward three camps or positions. Those who advocate BS to advance infant language, literacy, behavioral, and cognitive development rely heavily on anecdotal evidence and social media to support their claims. Those who advocate BS as an introduction to another language, such as American Sign Language (ASL), advocate early bilingual language learning. A third group warns against BS, emphasizing that it competes for attention with, and thereby potentially delays, spoken language acquisition in hearing infants. Empirical evidence to support any of these camps has been scarce.In this retrospective investigation we analyzed videotapes of sixteen infants from 9 through 18 months of age; eight had been exposed to BS, and eight had not been exposed to signing (NS). We compared their manual activity and found no differences in the quantity of manual activity accompanying vocal activity and no qualitative differences in the handshapes used during manual and vocal activity. More babies in the BS group reached the 4-, 10-, and 25-word milestones than babies in the NS group, but the differences were not statistically significant. In addition, monthly lexical growth from 12 to 18 months did not reveal signing to have a statistical impact on vocabulary acquisition.Discussion of these findings points to a tight relationship between manual and vocal activity in all sixteen babies, a relationship that aligns with previous theories and research on gestural and vocal development. Failure to find a statistical difference between the two groups’ development of words, however, calls for temperance in claiming that baby signing facilitates early word learning and cautions against claims that baby signing interferes with word learning.

The emergence of word representation independent of context

Eleven‐month‐old French‐learning infants prefer to listen to familiar over unfamiliar words (presented auditorily and independent of context), suggesting that there is a stable (although not necessarily complete) internal representation of word forms by this age [P. A. Halle and B. de Boysson‐Bardies, IBAD 17, 463–481 (1994)]. The current study explored word representation by infants learning British English. Infants at 9 and 11 months of age were tested using the headturn preference paradigm as modified by Halle and Boysson‐Bardies. Phonetically and phonotactically similar lists of familiar and unfamiliar disyllabic words and phrases were developed and matched for F0, amplitude and duration. The lists contained iambic and trochaic patterns in proportions typical for English. While initial results (based on looking times) suggest that the 11‐month‐old British infants, like the French, preferred the familiar over the unfamiliar list, 9‐month‐old infants showed no significant preference for either list. The...

Cross‐linguistic evidence for the acquisition of accent by the onset of word use

An investigation of the acoustic correlates of stress or accent in infant vocalizations was undertaken using five English‐ and five French‐learning participants at two developmental points, the onset of word use (10–13 months) and late in the single‐word period (14–19 months). A data base of 555 disyllabic utterances (words and babble) was digitized from naturalistic recordings and quantified acoustically by indices of duration, amplitude, and fundamental frequency (F0). Cluster analysis as well as the results of perceptual judgments (i.e., both a bottom‐up and a top‐down approach) revealed a developmental trend toward the adult prosodic system. In addition, acoustic comparisons of French and American infants at both developmental points revealed differences in their use of amplitude, F0, and duration to accent a syllable. The differences were traceable to the adult patterns for the respective adult languages. These results suggest that infants’ perceptual attunement to prosody in the prelinguistic period...