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.     

Depressed and Well Mothers' Emotion Interpretation Accuracy and the Quality of Mother—Infant Interaction

The inadequate parenting associated with mothers' depression may be related to mothers' problems in interpreting infants' emotional expressions. The relations between depressed and well mothers' accuracy at interpreting babies' facial expressions and the quality of the mothers' interactions with their infants were examined. In partial support of our hypotheses, depressed mothers' level of depressive symptoms was associated with less accuracy, especially regarding positive emotions. Contrary to expectations, depressed mothers did not differ from well mothers in terms of their emotion accuracy. Furthermore, depressed mothers' accuracy at interpreting infants' emotions was not significantly related to the quality of their interaction with their infants; in contrast, well mothers' accuracy for infants' negative emotions was associated with better interaction quality. These findings provide new information about depressed mothers' emotional interpretations and their parenting. The different pattern of findings for depressed and well mothers suggests that other mediating factors are important, which are discussed.     

Infants' Response to Maternal Mirroring in the Still Face and Replay Tasks

Infants' response to maternal mirroring was investigated in 4‐month‐old infants. Mother–infant dyads participated in the still face and replay tasks. Infants were grouped by those whose mothers did and did not mirror their behavior in the interactive phases of the tasks. In the still face task, infants with maternal mirroring showed more attention, smiling, and positive vocalizations across the phases, although both groups of infants demonstrated the still‐face effect with attention and smiling. Infants' social bidding to the mother during the still‐face phase correlated with mothers' mirroring behavior. In the replay task, infants with maternal mirroring demonstrated carryover effects with smiling; infants without maternal mirroring showed no awareness of change in their mothers' behavior. In both the still face and replay tasks, infants with maternal mirroring were more engaged with their mothers. Results suggest that maternal mirroring of infants' behavior affects infants' detection of, and response to, reciprocal interaction.     

Age‐Specific Preferences for Infant‐Directed Affective Intent

This study examined the developmental course of infants' attentional preferences for 3 types of infant‐directed affective intent, which have been shown to be commonly used at particular ages in the first year of life. Specifically, Kitamura and Burnham (2003) found mothers' tone of voice in infant‐directed speech is most comforting between birth and 3 months, most approving at 6 months, and most directive at 9 months. Thus, the aim of this study was to assess whether there is a relation between the type of affective intent used by mothers at each age point, and infants' affective intent preferences. Each infant group, 3‐, 6‐, and 9‐month‐olds, was played the 3 types of affective intent alternating across a single test session. When analyzed across age, the interactions revealed the predicted developmental trajectory; that is, infant preferences transformed between 3 and 6 months from comforting to approving, and between 6 and 9 months, from approving to directive. However, when analyzed separately by age, it was shown that 3‐month‐olds preferred comforting to other types; 6‐month‐olds preferred approving to directive, but listened equally to approving and comforting; and 9‐month‐olds showed no preference for any type of affective intent. Because it was possible that 9‐month‐olds were more focused on phonetic and phonotactic information, a new group of 9‐month‐olds was tested with intonation‐only versions of the 3 affective intent types. Under these conditions, they were found to prefer directive to comforting, but not directive to approving types. The results of this study have implications for what infants pay attention to in their social and linguistic environment over the course of the first year.     

Infant Affect During Parent—Infant Interaction at 3 and 6 Months: Differences Between Mothers and Fathers and Influence of Parent History of Depression

Fifty families participated in mother‐infant and father‐infant still‐face interaction at infant ages 3 and 6 months as part of a study of affect in early parent‐infant relationships. Infants' positive and negative affect and parents' positive affect and physical play were coded from videotapes. Consistent with previous research, during the normal condition, mothers displayed more positive affect than did fathers, and fathers were more likely than mothers to display physical play. Infants were more positive with mothers than with fathers. Parents' positive affect but not parent gender predicted infants' positive affect at 6 months. During the still‐face condition, infants of parents with a lifetime history of depression were more likely to display negative affect and less likely to display positive affect than infants with no such parent history. Infants' affect was unrelated to parents' current level of depressive symptoms, which indicates the value of considering family history of psychopathology when examining individual differences in infants' affect.     

Experimenter Affective Expression and Gaze Following in 7‐Month‐Olds

The study of gaze following in infants younger than 12 months of age has emphasized the effects of gesture, type of target, and its position or placement. This experiment extends this literature by examining the effects of adults' affective expression on 7‐month‐olds' gaze following. The effects of 3 affective expressions—happy, sad, and neutral—on 7‐month‐olds' frequency of gaze following were examined. The results indicated that infants more frequently followed the gaze of an adult posing a neutral expression than that of an adult posing either a happy or a sad expression. The infants also looked proportionately longer toward the indicated target when the adult's expression was neutral. The results are interpreted in terms of infants' flexibility of attention.     

Six‐Month‐Old Infants Prefer Speech with Raised Formant Frequencies

Voices can be characterized by their fundamental frequency as well as by speech timbre characteristics, such as formant frequencies. While infants' responses to fundamental frequency characteristics are well established, very little is known about how infants respond to changes in formant frequencies. This study tested whether 6‐month‐old infants prefer listening to speech with raised formant frequencies over speech with lowered formant frequencies. Naturally spoken utterances were acoustically manipulated to render raised‐formant and lowered‐formant stimuli that only differed in the formant frequencies, while keeping fundamental frequency and other acoustic characteristics constant. Infants in an infant‐controlled listening procedure listened longer to the raised‐formant than to the lowered‐formant stimuli. These results provide the first evidence that infants distinguish and show preferences for variations in formant frequencies in adult speech.     

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.     

Mother–Infant Person‐ and Object‐Directed Interactions in Latino Immigrant Families: A Comparative Approach

Cultural variation in durations, relations, and contingencies of mother–infant person‐and object‐directed behaviors were examined for 121 nonmigrant Latino mother–infant dyads in South America, Latina immigrants from South America and their infants living in the United States, and European American mother–infant dyads. Nonmigrant Latina mothers and infants engaged in person‐directed behaviors longer than Latino immigrant or European American mothers and infants. Mother and infant person‐directed behaviors were positively related; mother and infant object‐related behaviors were related for some cultural groups but not others. Nearly all mother and infant behaviors were mutually contingent. Mothers were more responsive to infants' behaviors than infants were to mothers. Some cultural differences in responsiveness emerged. Immigrant status has a differentiated role in mother–infant interactions.     

Emotion Regulation Via Maternal Touch

The study of emotion elicitation in the caregiver‐infant dyad has focused almost exclusively on the facial and vocal channels, whereas little attention has been given to the contribution of the tactile channel. This study was undertaken to investigate the effects of touch on infants' emotions. During the time that objects were presented to the dyad, mothers provided tactile stimulation to their 12‐month‐old infants by either (a) tensing their fingers around the infants' abdomen while abruptly inhaling, (b) relaxing their grip around the infants' abdomen, or (c) not providing additional tactile stimulation (control condition). The results revealed that infants in the first condition (a) touched the objects less and waited longer to touch the objects while displaying more negative emotional displays compared to infants in the control condition. However, no apparent differences were found between infants in the second condition (b) and the control condition. The results suggest that infants' emotions may be elicited by specific parameters of touch.     

Relations Between Mother‐Child Interactions and the Neural Correlates of Face Processing in 6‐Month‐Olds

Developmental studies of face processing have revealed age‐related changes in how infants allocate neurophysiological resources to the face of a caregiver and an unfamiliar adult. We hypothesize that developmental changes in how infants interact with their caregiver are related to the changes in brain response. We studied 6‐month‐olds because this age is frequently noted in the behavioral and neurophysiological literature as a time of transition in which infants begin to discriminate more readily between caregivers and unfamiliar adults. We used infants' behavioral responses to an original behavioral paradigm to predict event‐related potential (ERP) responses to pictures of the mother's face and a stranger's face in the same group of participants. Our results suggest that individual differences in infants' proximity‐seeking behaviors during interactions with the mother correlate with their neurophysiological responses to the mother's face as opposed to an unfamiliar face for the Nc component of the ERP. These results have implications for understanding the role of the changing infant‐caregiver relationship on the development of the face processing system in early infancy.     

Sensitivity to Social Contingency and Positive Emotion in 2‐Month‐Olds

This study was aimed at sorting out conflicting results in the literature concerning 2‐month‐olds' sensitivity to interpersonal contingency, and investigated the potential role of infants' positive emotion in contingency detection. Infants were randomly assigned to an experimental group (EG) that was presented an uninterrupted live–replay–live sequence of three 30‐sec episodes of their mothers' communicative behavior using a double video TV paradigm, or to a control group (CG) that was presented an uninterrupted 90 sec of contingent maternal interactions. Infants of the EG grimaced more than infants of the CG only during the 2nd period of social exchange (replay vs. 2nd live period), but there was an increase of grimacing and a reduction in gazing during the 3rd period of televised interactions in infants of the CG. Each group was split into 2 subgroups a posteriori according to the presence or absence of smiling during the 1st contingent episode. Smiling infants of the EG reacted more negatively during the 2nd interaction period compared to other subgroups. These findings support the view that sensitivity, not fatigue or loss of interest to maternal stimulation, accounts for 2‐month‐olds' expressive changes during noncontingent maternal interactions; fatigue or loss of interest better explains the decline in attention and the increase of negative expressiveness during the last period of contingent interaction. The findings also suggest that the emotional climate of dyadic exchanges could be a contributing factor to infants' ability to detect the relations between their own actions and those of their social partners.     

Sensitivity to Social Contingency From Mothers and Strangers in 2‐, 4‐, and 6‐Month‐Old Infants

Infants' sensitivity to changes in social contingency was investigated by presenting 2‐, 4‐, and 6‐month‐old infants with 3 episodes of social interaction from mothers and strangers: 2 contingent interactions and 1 noncontingent replay. Three orders were presented: (a) contingent, noncontingent, contingent; (b) contingent, contingent, noncontingent; and (c) noncontingent, contingent, contingent. Contingency and carryover effects were shown to both mothers and strangers in the different orders of presentation. Infants were more visually attentive to contingent interactions than to the noncontingent replay when contingent interactions occurred prior to the replay, and the infants' level of attention to the noncontingent replay carried over to subsequent contingent interactions. The 4‐ and 6‐month‐old infants showed contingency and carryover effects by their visual attention and smiling. Examination of effect sizes for attention suggests 2‐month‐old infants may be beginning to show the effects. Reasons for age changes in sensitivity to social contingency are discussed.     

Observed Infant Reactions During Live Interparental Conflict

Associations between interparental conflict and infant reactions were examined. Infants' history of exposure to interparental conflict and infant reactive temperament were examined as moderators. A community sample of 74 infants, aged 6–14 months, participated with their parents. Behavioral observations were made of parents' marital conflict and their infants' reactions. Parents reported on their emotional states during conflict, infants' history of exposure to interparental conflict, and infant temperament. Multilevel modeling indicated that infants showed differential responses to marital conflict; destructive and depressive conflict were associated with increased infant discussion attending and negative reactions, whereas constructive conflict was associated with decreased discussion attending and negative reactions. Infants' history of exposure to marital conflict and infant reactive temperament emerged as moderators.     

Attention to Maternal Multimodal Naming by 6‐ to 8‐Month‐Old Infants and Learning of Word–Object Relations

We examined whether mothers' use of temporal synchrony between spoken words and moving objects, and infants' attention to object naming, predict infants' learning of word–object relations. Following 5 min of free play, 24 mothers taught their 6‐ to 8‐month‐olds the names of 2 toy objects, Gow and Chi, during a 3‐min play episode. Infants were then tested for their word mapping. The videotaped episodes were coded for mothers' object naming and infants' attention to different naming types. Results indicated that mothers' use of temporal synchrony and infants' attention during play covaried with infants' word‐mapping ability. Specifically, infants who switched eye gaze from mother to object most frequently during naming learned the word–object relations. The findings suggest that maternal naming and infants' word‐mapping abilities are bidirectionally related. Variability in infants' attention to maternal multimodal naming explains the variability in early lexical‐mapping development.     

Coregulation and the Quality of the Relationship in Full‐Term and Very Low‐Birthweight Preterm Infant‐Mother Dyads During Face‐To‐Face Interactions

Interactions with parents build the foundation for infants' social–emotional development. This study investigated coregulation of the interaction and quality of relationship between mothers and their 6‐month‐old full‐term (n = 43) and very low‐birthweight/preterm (VLBW/preterm; n = 44; ages corrected for prematurity) infants. The objectives were to examine (1) how coregulation changed following a perturbed interaction, (2) how coregulation differed between full‐term and VLBW/preterm infant–mother dyads, and (3) the association between coregulation and relationship quality. Coregulation was coded using the Revised Relational Coding System (Fogel et al., 2003). Quality of the relationship was measured using the Emotional Availability scales (Biringen et al., 2014; Carter et al., 1998). Dyads participated in the Still‐Face (SF) procedure (Tronick et al., 1978) consisting of two natural and one SF period where mothers assumed a neutral expression, refraining from interacting with their infants. Following the SF period, dyads engaged in more symmetrical and more disruptive patterns of coregulation. While full‐term dyads engaged in more sequential‐symmetrical, VLBW/preterm dyads engaged in more resonant‐symmetrical coregulation. These results suggest that VLBW/preterm dyads may show more emotional reactivity in their interactions than full‐term dyads; however, in both groups infant responsiveness and parenting stress influenced the types of coregulation exhibited.     

Within‐rhythm Class Native Language Discrimination Abilities of Basque‐Spanish Monolingual and Bilingual Infants at 3.5 Months of Age

Language rhythm determines young infants' language discrimination abilities. However, it is unclear whether young bilingual infants exposed to rhythmically similar languages develop sensitivities to cross‐linguistic rhythm cues to discriminate their dual language input. To address this question, 3.5‐month‐old monolingual Basque, monolingual Spanish and bilingual Basque‐Spanish infants' language discrimination abilities (across low‐pass filtered speech samples of Basque and Spanish) have been tested using the visual habituation procedure. Although falling within the same rhythmic class, Basque and Spanish exhibit significant differences in their distributions of vocalic intervals (within‐rhythmic class variation). All infant groups in our study successfully discriminated between the languages, although each group exhibited a different pattern. Monolingual Spanish infants succeeded only when they heard Basque during habituation, suggesting that they were influenced by native language recognition. The bilingual and the Basque monolingual infants showed no such asymmetries and succeeded irrespective of the language of habituation. Additionally, bilingual infants exhibited longer looking times in the test phase as compared with monolinguals, reflecting that bilingual infants attend to their native languages differently than monolinguals. Overall, results suggest that bilingual infants are sensitive to within‐rhythm acoustic regularities of their native language(s) facilitating language discrimination and hence supporting early bilingual acquisition.     

Infant Brain Responses to Object Weight: Exploring Goal‐Directed Actions and Self‐Experience

Recent work has suggested the value of electroencephalographic (EEG) measures in the study of infants' processing of human action. Studies in this area have investigated desynchronization of the sensorimotor mu rhythm during action execution and action observation in infancy. Untested but critical to theory is whether the mu rhythm shows a differential response to actions which share similar goals but have different motor requirements or sensory outcomes. By varying the invisible property of object weight, we controlled for the abstract goal (reach, grasp, and lift the object), while allowing other aspects of the action to vary. The mu response during 14‐month‐old infants' own executed actions showed a differential hemispheric response between acting on heavier and lighter objects. EEG responses also showed sensitivity to “expected object weight” when infants simply observed an experimenter reach for objects that the infants' prior experience indicated were heavier vs. lighter. Crucially, this neural reactivity was predictive—during the observation of the other reaching toward the object, before lifting occurred. This suggests that infants' own self‐experience with a particular object's weight influences their processing of others' actions on the object, with implications for developmental social‐cognitive neuroscience.     

Is Agency Skin Deep? Surface Attributes Influence Infants' Sensitivity to Goal‐Directed Action

Three studies investigated the role of surface attributes in infants' identification of agents, using a habituation paradigm designed to tap infants' interpretation of grasping as goal directed (Woodward, 1998). When they viewed a bare human hand grasping objects, 7‐ and 12‐month‐old infants focused on the relation between the hand and its goal. When the surface properties of the hand were obscured by a glove, however, neither 7‐ nor 12‐month‐old infants represented its actions as goal directed (Study 1). Next, infants were shown that the gloved hands were part of a person either prior to (Study 2) or during (Study 3) the habituation procedure. Infants who actively monitored the gloved person in Study 2 and older infants in Study 3 interpreted the gloved reaches as goal directed. Thus, varying the extent to which an entity is identifiable as a person impacts infants' interpretation of the entity as an agent.     

Early Word Segmentation in Naturalistic Environments: Limited Effects of Speech Register

We examined 7.5‐month‐old infants' ability to segment words from infant‐ and adult‐directed speech (IDS and ADS). In particular, we extended the standard design of most segmentation studies by including a phase where infants were repeatedly exposed to target word recordings at their own home (extended exposure) in addition to a laboratory‐based familiarization. This enabled us to examine infants' segmentation of words from speech input in their naturalistic environment, extending current findings to learning outside the laboratory. Results of a modified preferential‐listening task show that infants listened longer to isolated tokens of familiarized words from home relative to novel control words regardless of register. However, infants showed no recognition of words exposed to during purely laboratory‐based familiarization. This indicates that infants succeed in retaining words in long‐term memory following extended exposure and recognizing them later on with considerable flexibility. In addition, infants segmented words from both IDS and ADS, suggesting limited effects of speech register on learning from extended exposure in naturalistic environments. Moreover, there was a significant correlation between segmentation success and infants' attention to ADS, but not to IDS, during the extended exposure phase. This finding speaks to current language acquisition models assuming that infants' individual attention to language stimuli drives successful learning.