Babble Research Articles

Behavioural biomarkers of typical Rett syndrome: moving towards early identification.

SummaryThe dynamic course of Rett syndrome (RTT) is still said to begin with a period of apparently normal development although there is mounting evidence that individuals with RTT show behavioural peculiarities and abnormalities during their infancy. Their spontaneous general movements are abnormal from birth onwards. Normal cooing vocalisation and canonical babbling (if at all required) are interspersed with abnormalities such as proto-vowel and proto-consonant alternations produced on ingressive airstream, breathy voice characteristics, and pressed or high-pitched vocalisations. The gestural repertoire is limited. Certain developmental motor and speech-language milestones are not at all acquired or show a significant delay. Besides abnormal blinking, repetitive and/or long lasting tongue protrusion, and bizarre smiling, there are already the first body and/or hand stereotypies during the first year of life. We are currently on a promising way to define a specific set of behavioural biomarkers pinpointing RTT.

Effects of Prenatal Nicotine Exposure on Infant Language Development: A Cohort Follow Up Study.

Objectives To study the longitudinal effects of prenatal nicotine exposure on cognitive development, taking into consideration prenatal and postnatal second-hand smoke exposure. Methods A cohort follow up study was carried out. One hundred and fifty-eight pregnant women and their infants were followed during pregnancy and infant development (at 6, 12, 30months). In each trimester of pregnancy and during postnatal follow-up, a survey was administered to obtain sociodemographic data and the details of maternal and close familial toxic habits. Obstetric and neonatal data were obtained from hospital medical records. To assess cognitive development, the Bayley Scales of Infant Development were applied at 6, 12 and 30months; to assess language development, the MacArthur-Bates Communicative Development Inventories were applied at 12months and the Peabody Picture Vocabulary Test at 30months. Results After adjustment for confounding variables, the results showed that infants prenatally exposed to cigarette smoke recorded poor cognitive development scores. Language development was most consistently affected, specifically those aspects related to auditory function (vocalizations, sound discrimination, word imitation, prelinguistic vocalizations, and word and sentence comprehension). Conclusions for Practice Irrespective of prenatal, perinatal and sociodemographic data (including infant postnatal nicotine exposure), prenatal exposure to cigarette smoke and second-hand smoke affect infant cognitive development, especially language abilities.

Babies Who Hear Their Own Babbling May Babble More

Babies Who Hear Their Own Babbling May Babble More

Learning to Produce Syllabic Speech Sounds via Reward-Modulated Neural Plasticity.

At around 7 months of age, human infants begin to reliably produce well-formed syllables containing both consonants and vowels, a behavior called canonical babbling. Over subsequent months, the frequency of canonical babbling continues to increase. How the infant’s nervous system supports the acquisition of this ability is unknown. Here we present a computational model that combines a spiking neural network, reinforcement-modulated spike-timing-dependent plasticity, and a human-like vocal tract to simulate the acquisition of canonical babbling. Like human infants, the model’s frequency of canonical babbling gradually increases. The model is rewarded when it produces a sound that is more auditorily salient than sounds it has previously produced. This is consistent with data from human infants indicating that contingent adult responses shape infant behavior and with data from deaf and tracheostomized infants indicating that hearing, including hearing one’s own vocalizations, is critical for canonical babbling development. Reward receipt increases the level of dopamine in the neural network. The neural network contains a reservoir with recurrent connections and two motor neuron groups, one agonist and one antagonist, which control the masseter and orbicularis oris muscles, promoting or inhibiting mouth closure. The model learns to increase the number of salient, syllabic sounds it produces by adjusting the base level of muscle activation and increasing their range of activity. Our results support the possibility that through dopamine-modulated spike-timing-dependent plasticity, the motor cortex learns to harness its natural oscillations in activity in order to produce syllabic sounds. It thus suggests that learning to produce rhythmic mouth movements for speech production may be supported by general cortical learning mechanisms. The model makes several testable predictions and has implications for our understanding not only of how syllabic vocalizations develop in infancy but also for our understanding of how they may have evolved.

The Influence of Interactive Context on Prelinguistic Vocalizations and Maternal Responses

ABSTRACTMany studies have documented influences of maternal responsiveness on cognitive and language development. Given the bidirectionality of interactions in caregiver-infant dyads, it is important to understand how infant behavior elicits variable responses. Prior studies have shown that mothers respond differentially to features of prelinguistic vocalizations that reflect phonological complexity; however, studies have also found that maternal responses vary as a function of interactive contexts. Thus, it is important to examine how infant phonological features and social context interact to influence maternal responsiveness because language development occurs in social interactions and moment-to-moment behaviors influence development. In the current study, we examined how maternal responses vary relative to infant vocal production and interactional context: puppet play, toy play, and book reading. Infants produced more syllable-like, consonant-vowels (CV) than vowel-like sounds (V) during book reading. Mothers responded to proportionally more CV vocalizations during book reading and puppet play than during toy play; however, it was only during book reading that mothers responded to CV sounds more than V sounds. Overall, mothers responded to CV sounds with imitations/expansions significantly more than other response types. Examining responses within contexts, however, acknowledgments were the most frequent response type, with naming responses during book reading and questions in the puppet context also occurring frequently. Therefore, maternal responses varied relative to both vocal characteristics and context, suggesting key variables in social interactions that may support language development.

Selective attention to a talker's mouth in infancy: role of audiovisual temporal synchrony and linguistic experience.

Previous studies have found that infants shift their attention from the eyes to the mouth of a talker when they enter the canonical babbling phase after 6 months of age. Here, we investigated whether this increased attentional focus on the mouth is mediated by audio-visual synchrony and linguistic experience. To do so, we tracked eye gaze in 4-, 6-, 8-, 10-, and 12-month-old infants while they were exposed either to desynchronized native or desynchronized non-native audiovisual fluent speech. Results indicated that, regardless of language, desynchronization disrupted the usual pattern of relative attention to the eyes and mouth found in response to synchronized speech at 10 months but not at any other age. These findings show that audio-visual synchrony mediates selective attention to a talker's mouth just prior to the emergence of initial language expertise and that it declines in importance once infants become native-language experts.

The Features Extraction of Infants Cries by Using Discrete Wavelet Transform Techniques

This article proposes the study and experiment of infant sound features extraction by using discrete wavelet transform (DWT) techniques. The DWTs using in this research are Haar, Symlet2 and Coiflet1 mother wavelets. In this classification, the Dunstan baby language is the infant sound data. The extracted features from the infant sound by DWT are learned by using the extreme learning machine (ELM) neural network. The results of this learning are compared in term of learning accuracy. From the experimental result, it is found that the average result of the ELM with Haar wavelet features extraction at number node of 30 is better than results of ELM with other wavelets in term of learning accuracy. However, there are insignificant differences in learning accuracy when the number of nodes is increased from 20 to 30 nodes.

Can you speak baby babble?

Can you speak baby babble?

Prelinguistic vocalizations distinguish pointing acts.

The current study investigated whether point-accompanying characteristics, like vocalizations and hand shape, differentiate infants' underlying motives of prelinguistic pointing. We elicited imperative (requestive) and declarative (expressive and informative) pointing acts in experimentally controlled situations, and analyzed accompanying characteristics. Experiment 1 revealed that prosodic characteristics of point-accompanying vocalizations distinguished requestive from both expressive and informative pointing acts, with little differences between the latter two. In addition, requestive points were more often realized with the whole hand than the index finger, while this was the opposite for expressive and informative acts. Experiment 2 replicated Experiment 1, revealing distinct prosodic characteristics for requestive pointing also when the referent was distal and when it had an index-finger shape. Findings reveal that beyond the social context, point-accompanying vocalizations give clues to infants' underlying intentions when pointing.

Early language development and phonetic repertoire in children with unrepaired cleft lip and palate: A preliminary study

Background: The development of pre-speech vocalizations, from the period of canonical babbling, is important for a child to develop speech and language. This is the stage when infants produce strings of consonant-vowel combinations with adult-like intonation patterns. Aims: The current study was aimed at analyzing the vocalizations of children with unrepaired cleft palate to compare the distribution of consonants, vowels, and syllable structures; and the development of receptive and expressive language with respect to age and gender matched typically developing children. Materials and Methods: Vocalizations of 10 children between 11 and 18 months of age with and without cleft of the palate were recorded during play and interaction with their mothers. One thousand utterances were transcribed using International Phonetic Alphabets by a speech language pathologist and analyzed for the above parameters. Language development was assessed using three-dimensional language acquisition test. Statistical Analysis: Mann-Whitney test was used to analyze the significance of differences between the two groups. Results: Statistically significant differences were obtained in the distribution of vowels and consonants among the utterances. The pattern of consonants and vowels noticed in children with cleft reflected the effects of structural constraints on sound production. An expressive language delay of 2-6 months was evidenced among children with cleft, though not statistically significant. Conclusion: Differences in prespeech vocalizations are noticed in children with cleft compared to typically developing children. The results highlighted the need for early intervention in children with cleft palate.

Frame aphasia due to Broca’s area impairment: a Persian case report

Background: Frame/content theory considers speech as a phenomenon evolved from mandibular cyclicities for the physiologic primitive functions of feeding.Aims: This case report emphasises two aspects: first, the speech clinical characteristics of a left hemisphere damaged patient, which may be regarded as evidence of frame/content theory because there appears to be a regression to the most primitive stages of canonical babbling, and second, regarding its localised brain impairment limited to Broca’s area boundaries.Methods & Procedures: We have provided a phonetically transcribed sample of speech and then analysed the articulated forms of syllables, mainly in words. A total of 403 syllables of the patient’s productions were analysed by articulatory phonetics method.Outcomes & Results: Many patterns of articulation of this case, especially the labial–central and fronted dorsal–front pattern, may reveal a “frame without content” pattern that we believe to be a case of frame aphasia.Conclusions: This patient may be considered as evidence of frame/content dissociation due to brain damage. Broca’s area’s role in subserving such a stage of content representation and loading in speech production is hypothesised.

Relationships between vocalization forms and functions in infancy: preliminary implications for early communicative assessment and intervention.

This preliminary study explored relationships between form and function in prelinguistic vocalizations to increase our understanding of early communicative development and to provide potential clinical implications for early communicative assessment and intervention. Twenty typically developing infants-5 infants in each of 4 age groups, from 3 to 20 months of age-were included. Vocalizations from these infants had previously been categorized for their form (Nathani, Ertmer, & Stark, 2006) and function (Stark, Bernstein, & Demorest, 1993) characteristics. In the present study, cross-classification tabulations between form and function were conducted to examine relationships between vocalization types and their apparent uses. As anticipated, earlier developing forms were mostly associated with earlier developing functions, and later developing forms were mostly associated with later developing functions. However, there were some exceptions such that some forms were associated with a variety of functions, and vice versa. The results suggest that some forms are more tightly coupled to function than others in the prelinguistic and early linguistic period. Preliminary implications for developmental theory, future research, and clinical applications are discussed. Larger, longitudinal studies with typical and atypical populations and stricter methodological controls are needed to validate these findings.

Observation is a valid way of assessing common variables in typical babbling and identifies infants who need further support.

It is important to identify speech and language difficulties in children as early as possible. This study investigated the validity of observing babbling structure and consonant articulation. We focused on the language capabilities of children, with and without cleft palates, at 12 months of age (n = 29) and 18 months of age (n = 38), comparing observations made by speech and language pathologists on babbling structure and consonant articulation to audio recordings phonetically transcribed by experts blinded to the aim of the study. Descriptive cross-tabs, sensitivity, specificity and predictive values were analysed to investigate the validity of agreement between the methods. We found high mean agreement between the two methods (94%) and within the observation (100%) and transcription (88.5%) teams when it came to canonical babbling, high-pressure/oral stop consonants and anterior placement of bilabial and dental/alveolar consonants. The observations had high specificity and negative predictive values (0.90-1) at both ages, with low to moderate sensitivity (0-0.86). However, there was low agreement, between and within the groups, on the number of consonant types and the unproven predictive variable glottal place of articulation. Previously suggested predictive measures of babbling were shown to be valid and observation is a reliable method of identifying children who need further support.

Using nonlinear methods to quantify changes in infant limb movements and vocalizations.

The pairing of dynamical systems theory and complexity science brings novel concepts and methods to the study of infant motor development. Accordingly, this longitudinal case study presents a new approach to characterizing the dynamics of infant limb and vocalization behaviors. A single infant's vocalizations and limb movements were recorded from 51-days to 305-days of age. On each recording day, accelerometers were placed on all four of the infant's limbs and an audio recorder was worn on the child's chest. Using nonlinear time series analysis methods, such as recurrence quantification analysis and Allan factor, we quantified changes in the stability and multiscale properties of the infant's behaviors across age as well as how these dynamics relate across modalities and effectors. We observed that particular changes in these dynamics preceded or coincided with the onset of various developmental milestones. For example, the largest changes in vocalization dynamics preceded the onset of canonical babbling. The results show that nonlinear analyses can help to understand the functional co-development of different aspects of infant behavior.

Maternal Responsiveness and the Development of Directed Vocalizing in Social Interactions

For effective communication, infants must develop the phonology of sounds and the ability to use vocalizations in social interactions. Few studies have examined the development of the pragmatic use of prelinguistic vocalizations, possibly because gestures are considered hallmarks of early pragmatic skill. The current study investigated infant vocal production and maternal responsiveness to examine the relationship between infant and maternal behavior in the development of infants' vocal communication. Specifically, we asked whether maternal responses to vocalizations could influence the development of prelinguistic vocal usage, as has been documented in recent experimental studies exploring the relation between maternal responses and phonological development. Twelve mother–infant dyads participated over a six‐month period (between 8 and 14 months of age). Mothers completed the MacArthur Communicative Development Inventory when infants were 15 months old. Maternal sensitive responses to infant vocalizations in the previous months predicted infants' mother‐directed vocalizations in the following months, rather than overall response rate. Furthermore, mothers' sensitive responding to mother‐directed vocalizations was correlated with an increase in developmentally advanced, consonant–vowel vocalizations and some language measures. This is the first study to document a social shaping mechanism influencing developmental change in pragmatic usage of vocalizations in addition to identifying the specific behaviors underlying development.

Interconnected growing self-organizing maps for auditory and semantic acquisition modeling

Based on the incremental nature of knowledge acquisition, in this study we propose a growing self-organizing neural network approach for modeling the acquisition of auditory and semantic categories. We introduce an Interconnected Growing Self-Organizing Maps (I-GSOM) algorithm, which takes associations between auditory information and semantic information into consideration, in this paper. Direct phonetic–semantic association is simulated in order to model the language acquisition in early phases, such as the babbling and imitation stages, in which no phonological representations exist. Based on the I-GSOM algorithm, we conducted experiments using paired acoustic and semantic training data. We use a cyclical reinforcing and reviewing training procedure to model the teaching and learning process between children and their communication partners. A reinforcing-by-link training procedure and a link-forgetting procedure are introduced to model the acquisition of associative relations between auditory and semantic information. Experimental results indicate that (1) I-GSOM has good ability to learn auditory and semantic categories presented within the training data; (2) clear auditory and semantic boundaries can be found in the network representation; (3) cyclical reinforcing and reviewing training leads to a detailed categorization as well as to a detailed clustering, while keeping the clusters that have already been learned and the network structure that has already been developed stable; and (4) reinforcing-by-link training leads to well-perceived auditory–semantic associations. Our I-GSOM model suggests that it is important to associate auditory information with semantic information during language acquisition. Despite its high level of abstraction, our I-GSOM approach can be interpreted as a biologically-inspired neurocomputational model.

Vocal Patterns in Infants with Autism Spectrum Disorder: Canonical Babbling Status and Vocalization Frequency

Canonical babbling is a critical milestone for speech development and is usually well in place by 10 months. The possibility that infants with autism spectrum disorder (ASD) show late onset of canonical babbling has so far eluded evaluation. Rate of vocalization or "volubility" has also been suggested as possibly aberrant in infants with ASD. We conducted a retrospective video study examining vocalizations of 37 infants at 9-12 and 15-18 months. Twenty-three of the 37 infants were later diagnosed with ASD and indeed produced low rates of canonical babbling and low volubility by comparison with the 14 typically developing infants. The study thus supports suggestions that very early vocal patterns may prove to be a useful component of early screening and diagnosis of ASD.

Prelinguistic infants’ communicative system: Role of caregiver social feedback

Infants’ prelinguistic vocalizations and gestures are rarely studied as a communicative system. As a result, there are few studies examining mechanisms of change concurrently in prelinguistic vocal and gesture behavior. Here we report the first evidence that contingent caregiver social feedback to infant gestures influences not only gesture production, but also prelinguistic vocal behavior. Study 1 demonstrates the relationship between gesture and vocal behavior in 12-month-old infants and contingent caregiver social feedback. Caregiver feedback to infant gesture production was positively associated with infant gestures, gesture–vocal combinations, and vocalizations. To test the mechanism underlying changes in infant gesture production, Study 2 instructed caregivers to respond either contingently or noncontingently to their infants’ gestures. Infants given contingent social feedback produced more gestures, more gesture–vocal combinations and used their vocalizations differently compared to infants given noncontingent feedback. Thus, prelinguistic vocal and gesture behavior are mechanistically linked before the first word and should be studied concurrently to understand the development of the communicative system.

Longitudinal Study of Early Vocalization Development in Toddlers with and without Cleft Palate from 6 to 18 Months of Age

Objectives: Early vocalization shows a close relationship with speech sound development and influences the onset of first words. This study explored longitudinally early vocalization development in toddlers with and without cleft palate from 6 to 18 months of age. Methods: The participants included 3 toddlers with cleft palate and 3 typically developing toddlers. Their vocalization samples were obtained with 3-month intervals from 6 or 7 to 18 months of age. The vocalization samples were analyzed based on the Stark assessment of early vocal development-revised and measures on vocalization types and each vocalization ratio were obtained. Results: Results indicated that group differences were observed in the ratio of level 2 at 18 months of age; toddlers with cleft palate exhibited a larger ratio of level 2 vocalization at 18 months of age. Two toddlers with cleft palate showed delayed vocalization developmental patterns during the entire period of the study. Toddlers with cleft palate showed decreases in level 2 which includes fully-resonant nuclei and two closant- vocant combinations. However, they did not exhibit remarkable changes in level 4 and 5 which include single consonant-vowel syllable, repeated canonical syllable, and jargon. Typically developing toddlers showed decreases in level 2 vocalization and progressive increases in level 4 and 5. Conclusion: This study suggested that toddlers with cleft palate generally showed delayed vocalization development compared to typically developing toddlers. The study results have implications for monitoring the development of pre-linguistic vocalization in toddlers with cleft palate.

Infants temporally coordinate gesture-speech combinations before they produce their first words

This study explores the patterns of gesture and speech combinations from the babbling period to the one-word stage and the temporal alignment between the two modalities. The communicative acts of four Catalan children at 0;11, 1;1, 1;3, 1;5, and 1;7 were gesturally and acoustically analyzed. Results from the analysis of a total of 4,507 communicative acts extracted from approximately 24h of at-home recordings showed that (1) from the early single-word period onwards gesture starts being produced mainly in combination with speech rather than as a gesture-only act; (2) in these early gesture-speech combinations most of the gestures are deictic gestures (pointing and reaching gestures) with a declarative communicative purpose; and (3) there is evidence of temporal coordination between gesture and speech already at the babbling stage because gestures start before the vocalizations associated with them, the stroke onset coincides with the onset of the prominent syllable in speech, and the gesture apex is produced before the end of the accented syllable. These results suggest that during the transition between the babbling stage and single-word period infants start combining deictic gestures and speech and, when combined, the two modalities are temporally coordinated.