Mothers' Speech to Hearing‐Impaired Infants and Children With Cochlear Implants

This study investigated the effects of age, hearing loss, and cochlear implantation on mothers' speech to infants and children. We recorded normal‐hearing (NH) mothers speaking to their children as they typically would do at home and speaking to an adult experimenter. Nine infants (10–37 months) were hearing‐impaired and had used a cochlear implant (CI) for 3 to 18 months. Eighteen NH infants and children were matched either by chronological age (10–37 months) or hearing experience (3–18 months) to the CI children. Prosodic characteristics such as fundamental frequency, utterance duration, and pause duration were measured across utterances in the speech samples. The results revealed that mothers use a typical infant‐directed speech style when speaking to hearing‐impaired children with CIs. The results also suggested that NH mothers speak with more similar vocal styles to NH children and hearing‐impaired children with CIs when matched by hearing experience rather than chronological age. Thus, mothers are sensitive to hearing experience and linguistic abilities of their NH children as well as hearing‐impaired children with CIs.     

Effects of Maternal Responsiveness on Infant Responsiveness and Behavior in the Still‐Face Task

The effects of maternal responsiveness on infant responsiveness and behavior in the Still‐Face Task were longitudinally examined through infants' first 3 months. Maternal vocal responsiveness and infant vocal and smiling responsiveness significantly increased when infants were 2 months of age. Mothers showed continuity of individual differences in vocal responsiveness from the infants' newborn period. Maternal responsiveness predicted infant responsiveness within and across sessions. Compared with infants with low‐responsive mothers, infants with high‐responsive mothers were more attentive and affectively engaged during the Still‐Face Task from 1 month of age. Infants with high‐responsive mothers discriminated between the task phases with their smiling at 1 month, a month before infants with low‐responsive mothers did so. Infants in both groups discriminated between the phases with their attention and nondistress vocalizations throughout their first 3 months. Results suggest that maternal responsiveness influences infant responsiveness and facilitates infants' engagement and expectations for social interaction.     

Infant‐directed speech to infants at risk for dyslexia: A novel cross‐dyad design

When mothers speak to infants at risk for developmental dyslexia, they do not hyperarticulate vowels in their infant‐directed speech (IDS). Here, we used an innovative cross‐dyad design to investigate whether the absence of vowel hyperarticulation in IDS to at‐risk infants is a product of maternal infant‐directed behavior or of infants’ parent‐directed cues. Interactions between mothers and infants who were at risk or not at risk for dyslexia were recorded in three conditions: when mothers interacted with (a) their own infants, (b) infants who were not their own but of the same risk status, and (c) infants who were not their own and of the opposite risk status. This design revealed both infant and parent effects. Mothers of not‐at‐risk infants hyperarticulated vowels significantly more when speaking to not‐at‐risk than to at‐risk infants. In contrast, mothers of at‐risk infants hyperarticulated vowels significantly less than NAR mothers, and this was irrespective of infant status. Mothers of not‐at‐risk infants thus adjusted their IDS to the infant's risk status, while mothers of at‐risk infants did not. We suggest that IDS is determined reciprocally by characteristics of both partners in the dyad: Both infant and maternal factors are essential for the vowel hyperarticulation component of IDS.     

Patterns of positivity: Positive affect trajectories among infants of mothers with a history of depression

This study examined positive affect (PA) trajectories over the first year of life among infants of mothers with a history of depression (N = 191) as well as predictors (i.e., maternal prenatal and postpartum depression symptoms, maternal parenting behaviors) of those trajectories. Infant PA was observed in play and feeding tasks during laboratory visits at 3, 6, and 12 months of age; parenting behaviors were observed at 3 months. Mothers completed questionnaires regarding their symptoms of depression throughout the prenatal period and during the first 3 months postpartum. Growth curve analyses indicated that infant PA increased across time, and this finding replicated across both the play and feeding tasks, though increases slowed over time. Neither maternal prenatal nor postpartum depression symptoms predicted infants' PA trajectories, but mothers' PA, positive parenting, and disengaged parenting were associated with infant PA during the play task. Our finding that infant PA increased over the first year postpartum suggests PA trajectories among infants of mothers with a history of depression may be indices of resilience, despite risks associated with their mothers' history of depression. Furthermore, this study highlights parenting behaviors that may be important targets of prevention and early intervention efforts to bolster infant PA.     

Mismatched response predicts behavioral speech discrimination outcomes in infants with hearing loss and normal hearing

Children with hearing loss (HL) remain at risk for poorer language abilities than normal hearing (NH) children despite targeted interventions; reasons for these differences remain unclear. In NH children, research suggests speech discrimination is related to language outcomes, yet we know little about it in children with HL under the age of 2 years. We utilized a vowel contrast, /a-i/, and a consonant-vowel contrast, /ba-da/, to examine speech discrimination in 47 NH infants and 40 infants with HL. At Mean age =3 months, EEG recorded from 11 scalp electrodes was used to compute the time-frequency mismatched response (TF-MMR_SE) to the contrasts; at Mean age =9 months, behavioral discrimination was assessed using a head turn task. A machine learning (ML) classifier was used to predict behavioral discrimination when given an arbitrary TF-MMR_SE as input, achieving accuracies of 73% for exact classification and 92% for classification within a distance of one class. Linear fits revealed a robust relationship regardless of hearing status or speech contrast. TF-MMR_SE responses in the delta (1–3.5 Hz), theta (3.5–8 Hz), and alpha (8–12 Hz) bands explained the most variance in behavioral task performance. Our findings demonstrate the feasibility of using TF-MMR_SE to predict later behavioral speech discrimination.     

Exploring the relation between maternal mind‐mindedness and children’s symbolic play: A longitudinal study from 6 to 18 months

Relations between mothers’ mind‐mindedness (appropriate attunement to their infants’ internal states) at 6 and 12 months and infants’ early symbolic play during infant–mother pretense at 12 and 18 months were investigated in a sample of 43 mothers and infants. Mothers’ appropriate mind‐related comments were associated with average level, length, complexity, and maturity level of symbolic play. Specific sub‐categories of appropriate mind‐related comments were identified as independent predictors of children's symbolic play. Appropriate comments about desires and cognitions at 6 months were associated with average level and length of episodes, as well as with maturity level of symbolic play at 12 months. Longitudinal stability in the appropriateness and content of mothers’ mind‐related comments was also investigated. The results are discussed in terms of the proposal that attunement to specific types of internal state should vary as a function of infant age in order to index mind‐mindedness.     

Pitch and Communicative Intent in Mother's Speech: Adjustments for Age and Sex in the First Year

This study investigated pitch and communicative intent in mothers' infant‐directed speech spoken to their infants at birth, 3, 6, 9, and 12 months. Audio recordings of mothers (6 with female, and 6 with male infants) talking to another adult and to their infant at 5 ages were low‐pass filtered and rated by 60 adults on 5 scales (Positive or Negative Affect, Express Affection, Encourage Attention, Comfort or Soothe, and Direct Behavior). Mean fundamental frequency (F₀) and pitch range of utterances were also measured. Utterances associated with positive affect tend to peak at 6 and 12 months, whereas more directive utterances peaked at 9 months. Mean F₀ followed the age trend for affective utterances, and pitch range followed the trend for directive utterances. The results suggest mother speech patterns reflect, complement, and perhaps facilitate infant development.     

Maternal Postpartum Depression Increases Vulnerability for Toddler Behavior Problems through Infant Cortisol Reactivity

The current study examined the role of hypothalamic‐pituitary‐adrenal reactivity (a physiological indicator of stress) in early infancy as a mediator of the relationship between maternal postpartum depression and toddler behavior problems. Participants were 137 at‐risk mothers and their children participating in a longitudinal study of intergenerational transmission of risk. Mothers’ depression was measured five times during the infants’ first 18 months. Infant cortisol was collected during a social stressor (the still‐face paradigm) when infants were 6 months old, and mothers reported on toddlers’ internalizing and externalizing symptoms at 18 months. Among this sample of high‐risk mother–infant dyads, early postpartum depression predicted atypical infant cortisol reactivity at 6 months, which mediated the effect of maternal depression on increased toddler behavior problems. Clinical implications are discussed.     

The Dynamics of Age and Sex in the Development of Mother–Infant Vocal Communication Between 3 and 11 Months

We followed the nondistressed vocalization dynamics of 30 mother–infant dyads observed in a naturalistic setting using multiple time points between 3 and 11 months to identify subtle relationships between age, sex and maternal behavior ending by 1 year of age with diverging trajectories of nondistressed vocalization. We observed no mean differences between boys and girls in frequency or duration of nondistressed vocalizations at any one time period. However, while these parameters were essentially static for boys, girls showed a quadratic developmental curve, declining in frequency and duration between 6 and 8 months and climbing above their early starting point by 9–11 months. Mothers of boys showed a linear decrease in the duration of their speech over the 9 months of our study. In contrast, mothers of girls showed quadratic patterns of ultimately increasing vocalization frequency and duration, over the months 3–11 of development. Finally, boys' and girls' vocalization contingent to maternal speech revealed no differences. Mothers of boys, however, did not change significantly over time, while mothers of girls showed an increase in contingent responsiveness from 3–5 months to 9–11 months and from 6–8 months to 9–11 months. A similar pattern was followed for object‐related maternal vocal responses.     

Infants’ Biological Sensitivity to the Effects of Maternal Social Support: Evidence Among Mexican American Families

The identification of infants who are most susceptible to both negative and positive social environments is critical for understanding early behavioral development. This study longitudinally assessed the interactive effects of infant vagal tone (respiratory sinus arrhythmia; RSA) and maternal social support on behavioral problems and competence among 322 low‐income Mexican American mother–infant dyads (infants: 54.1% female) and explored sex differences. Infant RSA was calculated from resting HR data at 6 weeks of age. Mothers reported on general social support, partner support, and family support at 6 months, and infant behavioral problems and competence at 1 year. Two‐way interactions (RSA × support source) were evaluated to predict behavioral problems and competence, adjusting for covariates. Results indicated higher competence among infants with lower RSA whose mothers reported higher general support or higher partner support. Interactive effects on behavior problems of RSA with maternal partner or family support were only found for female infants: Girls with higher RSA showed more behavior problems when mothers reported low support, but fewer problem levels in the context of high support. Our results suggest that infant RSA is an important moderator of the effects of the early social environment on early development.     

Associations between acoustic features of maternal speech and infants’ emotion regulation following a social stressor

Caregiver voices may provide cues to mobilize or calm infants. This study examined whether maternal prosody predicted changes in infants’ biobehavioral state after the still face, a stressor in which the mother withdraws and reinstates social engagement. Ninety-four dyads participated in the study (infant age 4–8 months). Infants’ heart rate and respiratory sinus arrhythmia (measuring cardiac vagal tone) were derived from an electrocardiogram (ECG). Infants’ behavioral distress was measured by negative vocalizations, facial expressions, and gaze aversion. Mothers’ vocalizations were measured via a composite of spectral analysis and spectro-temporal modulation using a two-dimensional fast Fourier transformation of the audio spectrogram. High values on the maternal prosody composite were associated with decreases in infants’ heart rate (β = ?.26, 95% CI: [?0.46, ?0.05]) and behavioral distress (β = ?.23, 95% CI: [?0.42, ?0.03]), and increases in cardiac vagal tone in infants whose vagal tone was low during the stressor (1 SD below mean β = .39, 95% CI: [0.06, 0.73]). High infant heart rate predicted increases in the maternal prosody composite (β = .18, 95% CI: [0.03, 0.33]). These results suggest specific vocal acoustic features of speech that are relevant for regulating infants’ biobehavioral state and demonstrate mother–infant bi-directional dynamics.     

Parental Speech at 6 Months Predicts Joint Attention at 12 Months

In a prospective longitudinal study of a representative community sample (N = 264), mothers' references to infants' mental states were coded during a topic‐sharing task in the home at 6 months. Joint attention behaviour was assessed in the laboratory at 12 months. Individual joint attention skills (gaze following, gaze alternating, and declarative pointing) were significantly inter‐correlated, with a single factor accounting for 68% of the variance. Mothers' references to infants' mental states at 6 months predicted infants' joint attention at 12 months. The association was not explained by sociodemographic characteristics of the family, the mother's mental state, or by the quantity or acoustic properties of her speech. However, variability in pitch of maternal speech was an independent predictor of the infants' later joint attention skills. Taken together, these findings suggest that mothers' infant‐directed speech fosters infants' attentive participation in topic‐sharing interactions, which in turn provide an important arena in which joint attention skills develop over the first year of life.     

Development of Infant Pointing from 10 to 12 months: The Role of Relevant Caregiver Responsiveness

Infants’ pointing frequency is a predictor of their later language abilities. Yet, predictors of pointing frequency in the first year of life are not well understood. Study 1 explored what factors in infants and caregivers at 10 months would predict the pointing frequency of infants at 12 months (N = 35). Infant‐driven predictors were infants’ fine‐motor skills and point‐following abilities. Caregiver‐mediated predictors were caregivers’ pointing frequency and responsiveness toward infants’ pointing. Relevant caregiver responsiveness at 10 months predicted infants’ pointing frequency at 12 months, controlling for the other factors and infants’ prior pointing frequency. Study 2 explored whether child‐level factors influence caregivers’ responsiveness (N = 49). We examined the hand shape of infants’ pointing (whole‐hand versus index‐finger) and the presence of point‐accompanying vocalizations. Infants’ vocalization‐accompanied points were more likely to elicit relevant responses from caregivers, while hand shapes played a less pronounced role. Together, the findings reveal an early emerging mutual relationship between infant pointing and caregiver behavior such that certain characteristics of infant pointing predict caregivers’ responsiveness, and relevant responsiveness toward infants’ pointing predicts the increase in infants’ pointing frequencies.     

Infant Preferences for Structural and Prosodic Properties of Infant‐Directed Speech in the Second Year of Life

While a large literature discusses young infants' preference for an infant‐directed speaking style, few studies have explored preferences after the first year. The present work compares infants' preference for two different properties of IDS speech: prosodic changes (primarily pitch and pitch variability) and structural properties (utterance length; lexical repetition). We found that both 12‐ and 16‐month‐old infants continued to prefer listening to speech with the prosodic properties of IDS, but neither age showed any preference for speech with the lexical repetition and short utterances typical of IDS.     

Prenatal Reflective Functioning and Accumulated Risk as Predictors of Maternal Interactive Behavior During Free Play,the Still‐Face Paradigm,and Two Teaching Tasks

This study examined whether prenatal reflective functioning (RF) was related to mothers’ interactive style across contexts with their 6‐month‐old infants (M age = 6.02 months, SD = 0.41, 54% boys), and to what extent quality of prenatal RF could account for the influence of accumulated risk on maternal interactive behavior. Accumulated risk was defined as the sum‐score of a selection of risk factors that have been associated with suboptimal infant development. Mother–infant dyads (N = 133) were observed during free play, two teaching tasks, and the Still‐Face Paradigm (SFP). Better prenatal RF was associated with more positive maternal behavior in all settings and less negative behavior during teaching and SFP reengagement. Accumulated risk and prenatal RF predicted shared variance in maternal interactive behavior (with unique predictive effects observed only for RF on sensitivity during teaching and SFP play, and for accumulated risk on sensitivity and positive engagement during SFP play, and internalizing‐helplessness during SFP reengagement). Accumulated risk had an indirect effect on maternal sensitivity during teaching and SFP play through prenatal RF. These findings suggest not only that RF may be targeted prenatally to improve mother–infant interactions, but also that enhancing RF skills may ameliorate some of the negative consequences from more stable perinatal risk factors that influence parent–child interactions.     

A Privileged Status for Male Infant‐Directed Speech in Infants of Depressed Mothers? Role of Father Involvement

Prior research showed that 5‐ to 13‐month‐old infants of chronically depressed mothers did not learn to associate a segment of infant‐directed speech produced by their own mothers or an unfamiliar nondepressed mother with a smiling female face, but showed better‐than‐normal learning when a segment of infant‐directed speech produced by an unfamiliar nondepressed father signaled the face. Here, learning in response to an unfamiliar nondepressed father’s infant‐directed speech was studied as a function both of the mother’s depression and marital status, a proxy measure of father involvement. Infants of unmarried mothers on average did not show significant learning in response to the unfamiliar nondepressed father’s infant‐directed speech. Infants of married mothers showed significant learning in response to male infant‐directed speech, and infants of depressed, married mothers showed significantly stronger learning in response to that stimulus than did infants of nondepressed, married mothers. Several ways in which father involvement may positively or negatively affect infant responsiveness to male infant‐directed speech are discussed.     

Maternal Disrupted Communication During Face‐to‐Face Interaction at 4 months: Relation to Maternal and Infant Cortisol Among at‐Risk Families

The study evaluated the association between maternal disrupted communication and the reactivity and regulation of the psychobiology of the stress response in infancy. Mothers and infants were recruited via the National Health Service from the 20% most economically impoverished data zones in a suburban region of Scotland. Mothers (N = 63; M age = 25.9) and their 4‐month‐old infants (35 boys, 28 girls) were videotaped interacting for 8 min, including a still‐face procedure as a stress inducer and a 5‐min coded recovery period. Saliva samples were collected from the dyads prior to, during, and after the still‐face procedure and later assayed for cortisol. Level of disruption in maternal communication with the infant was coded from the 5‐min videotaped interaction during the recovery period which followed the still‐face procedure. Severely disrupted maternal communication was associated with lower levels of maternal cortisol and a greater divergence between mothers' and infants' cortisol levels. Results point to low maternal cortisol as a possible mechanism contributing to the mother's difficulty in sensitively attuning to her infant's cues, which in turn has implications for the infant's reactivity to and recovery from a mild stressor in early infancy.     

Maternal neural reactivity during pregnancy predicts infant temperament

Maternal biological systems impact infant temperament as early as the prenatal period, though the mechanisms of this association are unknown. Using a prospective, longitudinal design, we found that maternal (N = 89) amplitudes of the late positive potential (LPP) in response to negative stimuli during the second, but not the third, trimester of pregnancy predicted observed and physiological indices of temperamental reactivity in infants at age 4 months. Maternal LPP was positively associated with observed infant fear and negatively associated with frontal EEG asymmetry and cortisol reactivity in infants at age 4 months. Results identify a putative mechanism, early in pregnancy, for the intergenerational transmission of emotional reactivity from mother to infant.     

Trajectories of Parenting During Infancy: The Role of Infant Temperament and Marital Adjustment for Mothers and Fathers

Although it is well accepted that parents greatly impact infant development, it is less clear which factors impact change in quantity and quality of parenting across infancy. This longitudinal study (N = 120 families) investigated how infant temperament and marital adjustment related to trajectories of mother and father involvement and sensitivity across infancy using multilevel models. Parental involvement (caregiving and play), infant temperament (surgency, negative affectivity, regulation), and marital adjustment were assessed from questionnaires when the infant was 3, 5, 7, 12, 14, and 20 months of age; parental sensitivity was coded from two episodes of the Still‐Face Paradigm in early infancy (3, 5, and 7 months). On average, mothers showed higher levels of caregiving, play, and sensitivity than fathers. Mother caregiving, play, and sensitivity increased over time. Father caregiving and play also increased over time, whereas sensitivity did not change with age. Happier marriages were related to increased play for both mothers and fathers. Infant surgency was also significantly related to caregiving, play, and sensitivity trajectories for mothers but not fathers. Findings are discussed in relation to parenting roles and family dynamics.