Enhanced gaze-following behavior in Deaf infants of Deaf parents

Leveraging technological advances to assess dyadic visual cognition during infancy in high- and low-resource settings

Caregiver-infant interactions shape infants' early visual experience; however, there is limited work from low-and middle-income countries (LMIC) in characterizing the visual cognitive dynamics of these interactions. Here, we present an innovative dyadic visual cognition pipeline using machine learning methods which captures, processes, and analyses the visual dynamics of caregiver-infant interactions across cultures. We undertake two studies to examine its application in both low (rural India) and high (urban UK) resource settings. Study 1 develops and validates the pipeline to process caregiver-infant interaction data captured using head-mounted cameras and eye-trackers. We use face detection and object recognition networks and validate these tools using 12 caregiver-infant dyads (4 dyads from a 6-month-old UK cohort, 4 dyads from a 6-month-old India cohort, and 4 dyads from a 9-month-old India cohort). Results show robust and accurate face and toy detection, as well as a high percent agreement between processed and manually coded dyadic interactions. Study 2 applied the pipeline to a larger data set (25 6-month-olds from the UK, 31 6-month-olds from India, and 37 9-month-olds from India) with the aim of comparing the visual dynamics of caregiver-infant interaction across the two cultural settings. Results show remarkable correspondence between key measures of visual exploration across cultures, including longer mean look durations during infant-led joint attention episodes. In addition, we found several differences across cultures. Most notably, infants in the UK had a higher proportion of infant-led joint attention episodes consistent with a child-centered view of parenting common in western middle-class families. In summary, the pipeline we report provides an objective assessment tool to quantify the visual dynamics of caregiver-infant interaction across high- and low-resource settings.

Use of pointing in parent-child interactions by hearing children of deaf and hearing parents: A follow-up from 1- to 3-years of age

Pointing plays a significant role in communication and language development. However, in spoken languages pointing has been viewed as a non-verbal gesture, whereas in sign languages, pointing is regarded to represent a linguistic unit of language. This study compared the use of pointing between seven bilingual hearing children of deaf parents (Kids of Deaf Adults [KODAs]) interacting with their deaf parents and five hearing children interacting with their hearing parents. Data were collected in 6-month intervals from the age of 1;0 to 3;0. Pointing frequency among the deaf parents and KODAs was significantly higher than among the hearing parents and their children. In signing dyads pointing frequency remained stable, whereas in spoken dyads it decreased during the follow-up. These findings suggested that pointing is a fundamental element of parent-child interaction, regardless of the language, but is guided by the modality, gestural and linguistic features of the language in question.

Family-Centered Early Intervention Deaf/Hard of Hearing (FCEI-DHH): Cultural & Global Implications

This article is the third in a series of eight articles that comprise this special issue on family-centered early intervention for children who are deaf or hard of hearing and their families (FCEI-DHH). It highlights the origins of FCEI-DHH in Western contexts and well-resourced locations and emphasizes the role of culture(s) in shaping FCEI-DHH. This article also cautions against the direct application of the 10 FCEI-DHH Principles presented in this issue across the globe without consideration of cultural implications. Cultural perceptions of decision-making processes and persons who can be decision-makers in FCEI-DHH are explored. Deaf culture(s) and the benefits of exposure to DHH adults with diverse backgrounds are introduced. Structural inequities that impact families' access to FCEI-DHH programs/services and systems, within and among nations and regions, are noted. The need to consider the cultural influences on families is emphasized; this applies to all levels of FCEI, including the development of systems through implementation of supports.

Family-Centered Early Intervention Deaf/Hard of Hearing (FCEI-DHH): Support Principles

This article is the sixth in a series of eight articles that comprise a special issue on Family-Centered Early Intervention (FCEI) for children who are deaf or hard of hearing (DHH) and their families, or FCEI-DHH. The Support Principles article is the second of three articles that describe the 10 Principles of FCEI-DHH, preceded by the Foundation Principles, and followed by the Structure Principles, all in this special issue. The Support Principles are composed of four Principles (Principles 3, 4, 5, and 6) that highlight (a) the importance of a variety of supports for families raising children who are DHH; (b) the need to attend to and ensure the well-being of all children who are DHH; (c) the necessity of building the language and communication abilities of children who are DHH and their family members; and (d) the importance of considering the family's strengths, needs, and values in decision-making.

Action value calculations in social context from infancy

Infants adaptively modulate their social behaviours, such as gaze-following, to social context. We propose that such modulations are based on infants' social decision-making, to achieve the most valuable outcome. We propose an 'action value calculator model', which formulates the cognitive mechanisms underlying, and the development of, the decision-making process during interactions.

ASL Developmental Trends Among Deaf Children, Ages Birth to Five

Language development is an important facet of early life. Deaf children may have exposure to various languages and communication modalities, including spoken and visual. Previous research has documented the rate of growth of English skills among young deaf children, but no studies have investigated the rate of ASL acquisition. The current paper examines young deaf children's acquisition of ASL skills, the rate of growth over time, and factors impacting levels and growth rates. Seventy-three children ages birth to 5 were rated three times using the Visual Communication and Sign Language Checklist and given a scaled score at each rating. An average monthly gain score was calculated for each participant. The presence of a deaf parent, use of ASL at home, use of cochlear implant(s), whether the child was born deaf, and age of initial diagnosis were analyzed for their impact on the level of ASL skill and rate of growth. Results indicated that the use of ASL in the home has a significant positive effect on deaf children's ASL skill level. Additionally, children with lower initial ratings showed higher rates of growth than those with higher initial ratings, especially among school-aged children. The paper discusses implications and directions for future studies.

The socialization of modality capital in sign language ecologies: A classroom example

Gaze behavior is an important component of children’s language, cognitive, and sociocultural development. This is especially true for young deaf children acquiring a signed language—if they are not looking at the language model, they are not getting linguistic input. Deaf caregivers engage their deaf infants and toddlers using visual and tactile strategies to draw in, support, and promote their child’s visual attention; we argue that these caregiver actions create a developmental niche that establishes the visual modality capital their child needs for successful sign language learning. But most deaf children do not have deaf signing parents (reportedly over 90%) and they will need to rely on adult signing teachers if they are to acquire a signed language at an early age. This study examines classroom interactions between a Deaf teacher, her teacher’s aide, and six deaf preschoolers to document the teachers’ “everyday practices” as they socialize the gaze behavior of these children. Utilizing a detailed behavioral and linguistic analysis of two video-recorded book-sharing contexts, we present data summarizing the teacher’s attention-getting actions directed toward the children and the discourse-embedded cues that signal the teacher’s expectations for student participation in the signed conversation. We observed that the teacher’s behaviors differed according to the parent status of the deaf preschooler (Deaf parents vs. hearing parents) suggesting that Deaf children of Deaf parents arrive to the preschool classroom with well-developed self-regulation of their attention or gaze. The teachers also used more physical and explicit cueing with the deaf children of hearing parents—possibly to promote their ability to leverage the visual modality for sign language acquisition. We situate these socialization patterns within a framework that integrates notions of intuitive or indigenous practices, developmental niche, and modality capital. Implications for early childhood deaf education are also discussed.

Visual attention for linguistic and non-linguistic body actions in non-signing and native signing children

Evidence from adult studies of deaf signers supports the dissociation between neural systems involved in processing visual linguistic and non-linguistic body actions. The question of how and when this specialization arises is poorly understood. Visual attention to these forms is likely to change with age and be affected by prior language experience. The present study used eye-tracking methodology with infants and children as they freely viewed alternating video sequences of lexical American sign language (ASL) signs and non-linguistic body actions (self-directed grooming action and object-directed pantomime). In Experiment 1, we quantified fixation patterns using an area of interest (AOI) approach and calculated face preference index (FPI) values to assess the developmental differences between 6 and 11-month-old hearing infants. Both groups were from monolingual English-speaking homes with no prior exposure to sign language. Six-month-olds attended the signer’s face for grooming; but for mimes and signs, they were drawn to attend to the “articulatory space” where the hands and arms primarily fall. Eleven-month-olds, on the other hand, showed a similar attention to the face for all body action types. We interpret this to reflect an early visual language sensitivity that diminishes with age, just before the child’s first birthday. In Experiment 2, we contrasted 18 hearing monolingual English-speaking children (mean age of 4.8 years) vs. 13 hearing children of deaf adults (CODAs; mean age of 5.7 years) whose primary language at home was ASL. Native signing children had a significantly greater face attentional bias than non-signing children for ASL signs, but not for grooming and mimes. The differences in the visual attention patterns that are contingent on age (in infants) and language experience (in children) may be related to both linguistic specialization over time and the emerging awareness of communicative gestural acts.

How experience shapes infants' communicative behaviour: Comparing gaze following in infants with and without pandemic experience

The COVID-19 pandemic has been influencing people's social life substantially. Everybody, including infants and children needed to adapt to changes in social interactions (e.g., social distancing) and to seeing other people wearing facial masks. In this study, we investigated whether these pandemic-related changes influenced 12- to 15-months-old infants' reactions to observed gaze shifts (i.e., their gaze following). In two eye-tracking tasks, we measured infants' gaze-following behavior during the pandemic (with-COVID-19-experience sample) and compared it to data of infants tested before the pandemic (no-COVID-19-experience sample). Overall, the results indicated no significant differences between the two samples. However, in one sub-task infants in the with-COVID-19-experience sample looked longer at the eyes of a model compared to the no-COVID-19-experience sample. Within the with-COVID-19-experience sample, the amount of mask exposure and the number of contacts without mask were not related to infants' gaze-following behavior. We speculate that even though infants encounter fewer different people during the pandemic and are increasingly exposed to people wearing facial masks, they still also see non-covered faces. These contacts might be sufficient to provide infants with the social input they need to develop social and emotional competencies such as gaze following.

Making sense of sensory language: Acquisition of sensory knowledge by individuals with congenital sensory impairments

The present article provides a narrative review on how language communicates sensory information and how knowledge of sight and sound develops in individuals born deaf or blind. Studying knowledge of the perceptually inaccessible sensory domain for these populations offers a lens into how humans learn about that which they cannot perceive. We first review the linguistic strategies within language that communicate sensory information. Highlighting the power of language to shape knowledge, we next review the detailed knowledge of sensory information by individuals with congenital sensory impairments, limitations therein, and neural representations of imperceptible phenomena. We suggest that the acquisition of sensory knowledge is supported by language, experience with multiple perceptual domains, and cognitive and social abilities which mature over the first years of life, both in individuals with and without sensory impairment. We conclude by proposing a developmental trajectory for acquiring sensory knowledge in the absence of sensory perception.

I See What You Are Saying: Hearing Infants’ Visual Attention and Social Engagement in Response to Spoken and Sign Language

Infants are endowed with a proclivity to acquire language, whether it is presented in the auditory or visual modality. Moreover, in the first months of life, listening to language supports fundamental cognitive capacities, including infants’ facility to form object categories (e.g., dogs and bottles). Recently, we have found that for English-acquiring infants as young as 4 months of age, this precocious interface between language and cognition is sufficiently broad to include not only their native spoken language (English), but also sign language (American Sign Language, ASL). In the current study, we take this work one step further, asking how “sign-naïve” infants—hearing infants with no prior exposure to sign language—deploy their attentional and social strategies in the context of episodes involving either spoken or sign language. We adopted a now-standard categorization task, presenting 4- to 6-month-old infants with a series of exemplars from a single category (e.g., dinosaurs). Each exemplar was introduced by a woman who appeared on the screen together with the object. What varied across conditions was whether this woman introduced the exemplar by speaking (English) or signing (ASL). We coded infants’ visual attentional strategies and their spontaneous vocalizations during this task. Infants’ division of attention and visual switches between the woman and exemplar varied as a function of language modality. In contrast, infants’ spontaneous vocalizations revealed similar patterns across languages. These results, which advance our understanding of how infants allocate attentional resources and engage with communicative partners across distinct modalities, have implications for specifying our theories of language acquisition.

Flexible fast-mapping: Deaf children dynamically allocate visual attention to learn novel words in American Sign Language

Word learning in young children requires coordinated attention between language input and the referent object. Current accounts of word learning are based on spoken language, where the association between language and objects occurs through simultaneous and multimodal perception. In contrast, deaf children acquiring American Sign Language (ASL) perceive both linguistic and non-linguistic information through the visual mode. In order to coordinate attention to language input and its referents, deaf children must allocate visual attention optimally between objects and signs. We conducted two eye-tracking experiments to investigate how young deaf children allocate attention and process referential cues in order to fast-map novel signs to novel objects. Participants were deaf children learning ASL between the ages of 17 and 71 months. In Experiment 1, participants (n = 30) were presented with a novel object and a novel sign, along with a referential cue that occurred either before or after the sign label. In Experiment 2, a new group of participants (n = 32) were presented with two novel objects and a novel sign, so that the referential cue was critical for identifying the target object. Across both experiments, participants showed evidence for fast-mapping the signs regardless of the timing of the referential cue. Individual differences in children's allocation of attention during exposure were correlated with their ability to fast-map the novel signs at test. This study provides first evidence for fast-mapping in sign language, and contributes to theoretical accounts of how word learning develops when all input occurs in the visual modality.

Mapping Word to World in ASL: Evidence from a Human Simulation Paradigm

Across languages, children map words to meaning with great efficiency, despite a seemingly unconstrained space of potential mappings. The literature on how children do this is primarily limited to spoken language. This leaves a gap in our understanding of sign language acquisition, because several of the hypothesized mechanisms that children use are visual (e.g., visual attention to the referent), and sign languages are perceived in the visual modality. Here, we used the Human Simulation Paradigm in American Sign Language (ASL) to determine potential cues to word learning. Sign-naïve adult participants viewed video clips of parent-child interactions in ASL, and at a designated point, had to guess what ASL sign the parent produced. Across two studies, we demonstrate that referential clarity in ASL interactions is characterized by access to information about word class and referent presence (for verbs), similarly to spoken language. Unlike spoken language, iconicity is a cue to word meaning in ASL, although this is not always a fruitful cue. We also present evidence that verbs are highlighted well in the input, relative to spoken English. The results shed light on both similarities and differences in the information that learners may have access to in acquiring signed versus spoken languages.

Language not auditory experience is related to parent-reported executive functioning in preschool-aged deaf and hard-of-hearing children

Much research has found disrupted executive functioning (EF) in deaf and hard‐of‐hearing (DHH) children; while some theories emphasize the role of auditory deprivation, others posit delayed language experience as the primary cause. This study investigated the role of language and auditory experience in parent‐reported EF for 123 preschool‐aged children (M_age = 60.1 months, 53.7% female, 84.6% White). Comparisons between DHH and typically hearing children exposed to language from birth (spoken or signed) showed no significant differences in EF despite drastic differences in auditory input. Linear models demonstrated that earlier language exposure predicted better EF (β = .061–.341), while earlier auditory exposure did not. Few participants exhibited clinically significant executive dysfunction. Results support theories positing that language, not auditory experience, scaffolds EF development.

Fathers of Young Deaf or Hard-of-Hearing Children: A Systematic Review

Much of the literature exploring the role of parents of children who are deaf or hard of hearing (DHH) has focused on mothers; yet, the involvement and perspectives of fathers is valuable and warrants attention. Following the PRISMA guidelines, this systematic literature review examined the peer-reviewed research that has differentially explored the experiences of fathers and mothers of young DHH children. Utilizing three databases (Web of Science, PsychINFO, Scopus) and spanning 50 years (1969-2019), 457 non-duplicated articles were identified that included the fathers of DHH children, birth to six years. Independent review of the titles, abstracts, and keywords by the authors limited these to 119. Full manuscripts were assessed for eligibility; 37 were deemed appropriate for inclusion in this systematic review. The papers included have been organized into the following themes: perspectives on parenting, parental stress and coping, parent-child interaction, involvement in early intervention, parental self-efficacy, and benefits of fathers' inclusion. Recommendations for future research include: (a) actively recruiting fathers in research, (b) differentially analyzing fathers' and mothers' experiences in research studies, (c) using information gleaned from research regarding father-child and mother-child interactions to guide interventions/programming, (d) recognizing the bidirectional influences of fathers and their DHH children, (e) moving beyond descriptive studies to explore fathers' influences on child outcomes, and (f) recognizing diverse family constellations.

Rapid development of perceptual gaze control in hearing native signing Infants and children

Children's gaze behavior reflects emergent linguistic knowledge and real-time language processing of speech, but little is known about naturalistic gaze behaviors while watching signed narratives. Measuring gaze patterns in signing children could uncover how they master perceptual gaze control during a time of active language learning. Gaze patterns were recorded using a Tobii X120 eye tracker, in 31 non-signing and 30 signing hearing infants (5-14 months) and children (2-8 years) as they watched signed narratives on video. Intelligibility of the signed narratives was manipulated by presenting them naturally and in video-reversed ("low intelligibility") conditions. This video manipulation was used because it distorts semantic content, while preserving most surface phonological features. We examined where participants looked, using linear mixed models with Language Group (non-signing vs. signing) and Video Condition (Forward vs. Reversed), controlling for trial order. Non-signing infants and children showed a preference to look at the face as well as areas below the face, possibly because their gaze was drawn to the moving articulators in signing space. Native signing infants and children demonstrated resilient, face-focused gaze behavior. Moreover, their gaze behavior was unchanged for video-reversed signed narratives, similar to what was seen for adult native signers, possibly because they already have efficient highly focused gaze behavior. The present study demonstrates that human perceptual gaze control is sensitive to visual language experience over the first year of life and emerges early, by 6 months of age. Results have implications for the critical importance of early visual language exposure for deaf infants. A video abstract of this article can be viewed at https://www.youtube.com/watch?v=2ahWUluFAAg.

Acquisition of Sign Languages

Natural sign languages of deaf communities are acquired on the same time scale as that of spoken languages if children have access to fluent signers providing input from birth. Infants are sensitive to linguistic information provided visually, and early milestones show many parallels. The modality may affect various areas of language acquisition; such effects include the form of signs (sign phonology), the potential advantage presented by visual iconicity, and the use of spatial locations to represent referents, locations, and movement events. Unfortunately, the vast majority of deaf children do not receive accessible linguistic input in infancy, and these children experience language deprivation. Negative effects on language are observed when first-language acquisition is delayed. For those who eventually begin to learn a sign language, earlier input is associated with better language and academic outcomes. Further research is especially needed with a broader diversity of participants.

The development of gaze following in monolingual and bilingual infants: A multi-laboratory study

Determining the meanings of words requires language learners to attend to what other people say. However, it behooves a young language learner to simultaneously encode relevant non-verbal cues, for example, by following the direction of their eye gaze. Sensitivity to cues such as eye gaze might be particularly important for bilingual infants, as they encounter less consistency between words and objects than monolingual infants, and do not always have access to the same word-learning heuristics (e.g., mutual exclusivity). In a preregistered study, we tested the hypothesis that bilingual experience would lead to a more pronounced ability to follow another's gaze. We used a gaze-following paradigm developed by Senju and Csibra (Current Biology, 18, 2008, 668) to test a total of 93 6- to 9-month-old and 229 12- to 15-month-old monolingual and bilingual infants, in 11 laboratories located in 8 countries. Monolingual and bilingual infants showed similar gaze-following abilities, and both groups showed age-related improvements in speed, accuracy, frequency, and duration of fixations to congruent objects. Unexpectedly, bilinguals tended to make more frequent fixations to on-screen objects, whether or not they were cued by the actor. These results suggest that gaze sensitivity is a fundamental aspect of development that is robust to variation in language exposure.

Lexical Recognition in Deaf Children Learning American Sign Language: Activation of Semantic and Phonological Features of Signs

Children learning language efficiently process single words, and activate semantic, phonological, and other features of words during recognition. We investigated lexical recognition in deaf children acquiring American Sign Language (ASL) to determine how perceiving language in the visual-spatial modality affects lexical recognition. Twenty native- or early-exposed signing deaf children (ages 4 to 8 years) participated in a visual world eye-tracking study. Children were presented with a single ASL sign, target picture, and three competitor pictures that varied in their phonological and semantic relationship to the target. Children shifted gaze to the target picture shortly after sign offset. Children showed robust evidence for activation of semantic but not phonological features of signs, however in their behavioral responses children were most susceptible to phonological competitors. Results demonstrate that single word recognition in ASL is largely parallel to spoken language recognition among children who are developing a mature lexicon.

Relational Factors in Pragmatic Skill Development: Deaf and Hard of Hearing Infants and Toddlers

In this article, we review relational factors in early childhood believed to contribute in unique ways to pragmatic skill development in deaf and hard of hearing (DHH) infants and toddlers. These factors include attending to infant interactions with caregivers and others, supporting development of theory of mind through play and use of mental state language (ie, describing one's own or others' thoughts, feelings, and beliefs), and providing accessible opportunities for social interaction. On the basis of a review of the literature and clinical experience, we offer prescriptive strategies for supporting DHH children's development in these areas. To improve outcomes for DHH children, medical care providers and allied health professionals have a responsibility to support the development of young DHH children's pragmatic abilities by understanding these variables, coaching caregivers regarding their importance, and facilitating referrals for support when necessary.

Early Pragmatics in Deaf and Hard of Hearing Infants

BACKGROUND AND OBJECTIVES

A set of important pragmatic skills emerge during infancy and pave the way for later language learning. It is thought these early social communication skills develop through infant-caregiver interaction. In a microanalysis, we tested whether deaf and hard of hearing (DHH) infants (typically at high risk of reduced access to rich communicative interaction in infancy) are less likely to engage in gestural and vocal pragmatic behaviors.

METHODS

We coded the naturalistic communication of 8 DHH infants who had no additional needs, who were not preterm or low birth weight, whose parents were hearing, monolingual English speakers, and who had spoken English as their primary target language. The frequency of use of 5 types of infant communication known to positively predict later language development (show gestures, give gestures, index-finger pointing, communicative vocalizations, and early word use) was compared with that of 8 typically hearing infants matched for age, sex, and socioeconomic status.

RESULTS

Hearing loss had a significant negative effect on the frequency with which infants engaged in all types of early communication that predict later language development.

CONCLUSIONS

DHH infants are at high risk of delay in the gestural and vocal communicative skills that lay the foundations for later language. Delay in the gestural domain suggests this is not simply a consequence of difficulties in imitating auditory stimuli. There is significant potential to lift DHH infants onto a positive developmental trajectory by supporting caregivers to nurture interaction from the first year.

Social and emotional contexts predict the development of gaze following in early infancy

The development of gaze following begins in early infancy and its developmental foundation has been under heavy debate. Using a longitudinal design (N = 118), we demonstrate that attachment quality predicts individual differences in the onset of gaze following, at six months of age, and that maternal postpartum depression predicts later gaze following, at 10 months. In addition, we report longitudinal stability in gaze following from 6 to 10 months. A full path model (using attachment, maternal depression and gaze following at six months) accounted for 21% of variance in gaze following at 10 months. These results suggest an experience-dependent development of gaze following, driven by the infant's own motivation to interact and engage with others (the social-first perspective).