Are infants' preferences in the number change detection paradigm driven by sequence patterns?

Inter-individual differences in infants' numerosity processing have been assessed using a change detection paradigm, where participants were presented with two concurrent streams of images, one alternating between two numerosities and the other showing one constant numerosity. While most infants look longer at the changing stream in this paradigm, the reasons underlying these preferences have remained unclear. We suggest that, besides being attracted by numerosity changes, infants perhaps also respond to the alternating pattern of the changing stream. We conducted two experiments (N = 32) with 6-month-old infants to assess this hypothesis. In the first experiment, infants responded to changes in numerosity even when the changing stream showed numerosities in an unpredictable random order. In the second experiment, infants did not display any preference when an alternating stream was pitted against a random stream. These findings do not provide evidence that the alternating pattern of the changing stream contributes to drive infants' preferences. Instead, around the age of 6 months, infants' responses in the numerosity change detection paradigm appear to be mainly driven by changes in numerosity, with different levels of preference reflecting inter-individual difference in the acuity of numerosity perception.     

Temperamental Susceptibility to Parenting among Preterm and Full‐Term Infants in Early Cognitive Development

The current study examined the interaction between premature birth, temperamental reactivity, and parenting in early cognitive development. Participants were 142 infants (80 preterm; 62 full term) and their parents. Parent–child interactions (maternal, paternal, and co‐parental) were observed at age 6 months to assess parental structuring behaviors. Additionally, both parents reported on infants' temperamental reactivity. At 12 months of age, infants' cognitive abilities were assessed. Consistent with the diathesis–stress model, preterm infants had lower cognitive outcomes than full‐term infants when exposed to low levels of co‐parental structuring, but functioned similarly when exposed to high levels of co‐parental structuring. However, temperamental reactivity moderated this effect: Infants who carried one susceptibility factor (i.e., premature birth or reactive temperament) were similarly affected by co‐parental structuring, whereas infants who carried two or no susceptibility factors were not. Furthermore, consistent with the differential susceptibility hypothesis, infants with highly reactive temperaments had lower cognitive functioning when exposed to low maternal structuring, but higher cognitive functioning when exposed to high maternal structuring compared to infants with lower reactivity. Results from this study highlight the importance of considering both temperamental reactivity and quality of parenting in understanding preterm infants' early cognitive vulnerability.     

Father-mother infant interaction in traditional and nontraditional Swedish families: A longtitudinal study

The effects of parental gender and caretaking role on parental attitudes, parent-infant interaction, infant-parent attachment, infants' sociability with strangers and their parental preferences were examined in a longitudinal study of fifty-one Swedish couples. Fathers who later spent more than a month out of the first nine as primary caretakers were considered involved or nontraditional. The parents were interviewed separately, prenatally, and five months postnatally. Parent-infant interaction was observed, security of attachment and sociability with strangers were assessed, and the infants' parental preferences were determined. Many parental attitudes were stable from the pre-to postnatal interview. Parenthood and work were more highly valued by nontraditional than traditional parents. Regardless of relative involvement in child care, infants directed more affiliative and attachment behaviors to their mothers than to their fathers. No relationship was found between relative parental involvement and the security of infant attachment. There was also no relationship between the security of infant-mother and infant-father attachments.     

The Microstructure of Infants' Gaze as They View Adult Shifts in Overt Attention

We presented infants (5, 6, 9, and 12 months old) with movies in which a female model turned toward and fixated 1 of 2 toys placed on a table. Infants' gaze was measured using a Tobii 1750 eye tracker. Six‐, 9‐, and 12‐month‐olds' first gaze shift from the model's face (after the model started turning) was directed to the attended toy. The 5‐month‐olds performed at random. Following this initial response, 5‐, 6‐, and 9‐month‐olds performed more gaze shifts to the attended target; 12‐month‐olds performed at random. Infants at all ages displayed longer looking times to the attended toy. We discuss a number of explanations for 5‐month‐olds' ability to follow a shift in overt attention by an adult after an initially random response, including the possibility that infants' initial gaze response strengthens the representation of the objects in the peripheral visual field.     

Dyadic Interaction: Greater than the Sum of its Parts?

The study of dyadic interaction plays a major role in infancy research. To advance conceptually informed measurement of dyadic interaction and integration across studies, we examined factor structure of individual parents' and infants' measures and dyadic measures from face‐to‐face interactions in two samples of 6‐month‐old infants and their parents: mothers from a demographically heterogeneous sample (N = 164), and mothers and fathers (N = 156) from a Caucasian middle‐class sample. Results suggested that a) individual and dyadic measures, and parents' and infants' behaviors contribute independent information, b) measures of both valence and process are needed, c) there are context‐general and context‐specific qualities, and d) structure of dyadic interaction is more similar among mother–infant dyads from independent samples than between mother–infant and father–infant dyads within the same sample. Future research should use multiple measures incorporating valence, temporal processes, contextual influences, and behaviors of individual partners along with dyadic measures to adequately assess the quality of dyadic interaction.     

Infants' identification of gender in biological motion displays

Infants' knowledge of social categories, including gender-typed characteristics, is a vital aspect of social cognitive development. In the current study, we examined 9- to 12-month-old infants' understanding of the categories “male” and “female” by testing for gender matching in voices or faces with biological motion depicted in point light displays (PLDs). Infants did not show voice–PLD gender matching spontaneously (Experiment 1) or after “training” with gender-matching voice–PLD pairs (Experiment 2). In Experiment 3, however, infants were trained with gender-matching face–PLD pairs and we found that patterns of visual attention to top regions of PLD stimuli during training predicted gender matching of female faces and PLDs. Prior to the end of the first postnatal year, therefore, infants may begin to identify gender in human walk motions, and perhaps form social categories from biological motion.     

An object's categorizability impacts whether infants encode surface features into their object representations

Infants encode the surface features of simple, unfamiliar objects (e.g., red triangle) and the categorical identities of familiar, categorizable objects (e.g., car) into their representations of these objects. We asked whether 16–18-month-olds ignore non-diagnostic surface features (e.g., color) in favor of encoding an object's categorical identity (e.g., car) when objects are from familiar categories. In Experiment 1 (n = 18), we hid a categorizable object inside an opaque box. In No Switch trials, infants retrieved the object that was hidden. In Switch trials, infants retrieved a different object: an object from a different category (Between-Category-Switch trials) or a different object from the same category (Within-Category-Switch trials). We measured infants' subsequent searching in the box. Infants' pattern of searching suggested that only infants who completed a Within-Category-Switch trial as their first Switch trial encoded objects' surface features, and an exploratory analysis suggested that infants who completed a Between-Category-Switch trial as their first Switch trial only encoded objects' categories. In Experiment 2 (n = 18), we confirmed that these results were due to objects' categorizability. These results suggest infants may tailor the way they encode categorizable objects depending on which object dimensions are perceived to be task relevant.     

Further Evidence for Infants' Preference for Prosocial Over Antisocial Behaviors

This study extends the findings that young infants prefer prosocial to antisocial others (Hamlin & Wynn, Cognitive Development 2011, 26, 30; Hamlin, Wynn, & Bloom, Nature 2007, 450, 557) to older infants (12–24 and 24–36 months) with a novel display. We presented infants with short cartoons in which a character (the “Protoganist”) engaged in a ball play with two others, one acting prosocially (the “Giver”), and the other antisocially (the “Keeper”). Afterward, infants were presented with the Giver and the Keeper characters and encouraged to reach for the one of their choices. We found that infants exhibited robust choice for the Giver. In addition, infants' preference for the Giver persisted despite changes in facial features (dark skin, scrambled face). These findings provide further evidence for infant's preference for prosociality.     

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.     

Face Preferences for Infant‐ and Adult‐Directed Speakers in Infants of Depressed and Nondepressed Mothers: Association with Infant Cognitive Development

Face preferences for speakers of infant‐directed and adult‐directed speech (IDS and ADS) were investigated in 4‐ to 13.5‐month‐old infants of depressed and nondepressed mothers. Following 1 min of exposure to an ID or AD speaker (order counterbalanced), infants had an immediate paired‐comparison test with a still, silent image of the familiarized versus a novel face. In the test phase, ID face preference ratios were significantly lower in infants of depressed than nondepressed mothers. Infants' ID face preference ratios, but not AD face preference ratios, correlated with their percentile scores on the cognitive (Cog) scale of the Bayley Scales of Infant & Toddler Development (3rd Edition; BSID‐III), assessed concurrently. Regression analyses revealed that infant ID face preferences significantly predicted infant Cog percentiles even after demographic risk factors and maternal depression had been controlled. Infants may use IDS to select social partners who are likely to support and facilitate cognitive development.     

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.     

Correlates of infant pointing frequency in the first year

This study examines the emergence of concurrent correlates of infant pointing frequency with the aim of contributing to its ontogenetic theories. We measured monthly from 8 to 12 months infants' (N = 56) index-finger pointing frequency along with several candidate correlates: (1) family socioeconomic status (SES), (2) mothers' pointing production, and (3) infants' point following to targets in front of and behind them. Results revealed that (1) infants increased their pointing frequency across age, but high-SES infants had a steeper increase, and a higher pointing frequency than low-SES infants from 10 months onward, (2) maternal pointing frequency was not associated with infant pointing frequency at any age, (3) infants' point following abilities to targets behind their visual fields was positively associated with their pointing frequency at 12 months, after pointing had already emerged around 10 months. Findings suggest that family SES impacts infants' pointing development more generally, not just through maternal pointing. The association between pointing and following points to targets behind, but not in front, suggests that a higher level of referential understanding emerges after, and perhaps through the production of pointing.     

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.     

Infants' Acquisition of Grammatical Gender Dependencies

To successfully understand spoken language, listeners need to determine how words within sentences relate to one another. Although the ability to compute relationships between word categories is known to develop early in life, little research has been conducted on infants' early sensitivity to subcategorical dependencies, such as those evoked by grammatical gender (where the article form is dictated by the noun's gender). This study therefore examines whether French‐learning 18‐month‐olds track such relationships. Using the Visual Fixation Procedure, infants were presented with article–noun sequences in which the gender‐marked article either matched (e.g., la_FEM poussette_FEM “the stroller”) or mismatched (e.g., le_MASC poussette_FEM) the gender of the noun. A clear preference for correct over incorrect co‐occurrences was observed, suggesting that by 18 months of age, children's storage and access of words is sufficiently sophisticated to include the means to track subcategorical dependencies. This early sensitivity to gender information may be greatly beneficial for constraining lexical access during online language processing.     

Stress Pattern Preference in Spanish‐Learning Infants: The Role of Syllable Weight

As a result of exposure, infants acquire biases that conform to the rhythmic properties of their native language. Previous lexical stress preference studies have shown that English‐ and German‐, but not French‐learning infants, show a bias toward trochaic words. The present study explores Spanish‐learning infants' lexical stress preferential patterns and the role of syllable weight at 9 months of age. Spanish is a syllable‐timed language with no vowel reduction and variable stress. Around 50% of the word types in Spanish are disyllabic, with a superior proportion of trochees than iambs (60% and 40%, respectively). Experiment 1 with CV.CV pseudo‐words failed to reveal a clear trochaic bias in 9‐month‐old Spanish‐learning infants. However, when preference was explored with items containing a heavy syllable (CVC.CV and CV.CVC, respectively), both a trochaic (Experiment 2) and an iambic preference (Experiment 3) could be elicited. These results suggest that knowledge about the close and highly regular link between heavy syllables and stress assignment in Spanish can be easily acquired and determines infants' preference at 9 months of age, while for CV.CV items, the trochaic bias appears to be weak. Our results broaden the current knowledge on the factors that determine the emergence of rhythmic biases.     

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.     

Infants’ response to a mobile phone modified still‐face paradigm: Links to maternal behaviors and beliefs regarding technoference

Interruptions to parent–child interactions due to technology, or “technoference,” have been correlated with a host of negative child developmental outcomes. Yet, the influence of technoference on parent–infant interactions and infant behaviors has received less attention and more experimental work is warranted. For this study, parent–infant dyads (n = 227) completed a modified still‐face paradigm (SFP) using a mobile phone during the still‐face phase. Infant responses were coded for positive and negative affect, object and parent orientation, self‐comforting, and escape behaviors during the task. Results showed a robust still‐face effect, with infants displaying increased negative affect, decreased positive affect, increased self‐comforting, object orientation, and escape behaviors during the “still‐face” or phone distracted phase of the paradigm and frequently failing to return to baseline during the reunion phase. Older infants (older than 9 months) likewise demonstrated higher levels of negative affect across all three phases of the paradigm relative to younger infants (less than 9 months). Parent reports of technoference behavior were related to increased object orientation for younger infants. Parental technoference behaviors were also linked to more escape behaviors for younger infants and decreased object orientation in older infants during the still‐face portion of the SFP. Higher levels of technoference also appear to attenuate the negative emotional response of infants during still face. Results are discussed in relation to infants’ increasing exposure to digital technology in the context of early relationships.     

Evidence of the Face Inversion Effect in 4‐Month‐Old Infants

This study tested the presence of the face inversion effect in 4‐month‐old infants using habituation to criterion followed by a novelty preference paradigm. Results of Experiment 1 confirmed previous findings, showing that when 1 single photograph of a face is presented in the habituation phase and when infants are required to recognize the same photograph, no differences in recognition performance with upright and inverted faces are found. However, Experiment 2 showed that, when infants are habituated to a face shown in a variety of poses and are required to recognize a new pose of the same face, infants' recognition performances were higher for upright than for inverted faces. Overall, results indicate that, under some experimental conditions, 4‐month‐olds process faces differently according to whether faces are presented upright or inverted.     

Maternal Into‐The‐Face Behavior,Shared Attention,and Infant Distress During Face‐to‐Face Play at 12 Months: Bi‐directional Contingencies

We describe a new maternal intrusion behavior, moving a toy or hand “into‐the‐face” of the infant, and we investigate its bi‐directional associations with infant‐initiated shared attention, infant distress, and infant gaze, during mother–infant face‐to‐face play at 12 months. The play was videotaped split‐screen, with infants seated in a high chair. Videotapes were coded on a 1‐sec time base for mother and infant gaze (at partner, toy, both, or gaze away); infant distress; and maternal intrusion behavior, “into‐the‐face.” We defined “infant‐initiated shared attention” as mother and infant looking in the same second at a toy that the infant‐initiated interest in. We documented that maternal into‐the‐face behavior decreased the likelihood of infant‐initiated shared attention, increased the likelihood of infant distress, and decreased the likelihood of infant gazing away. Reciprocally, infant distress and gazing away increased the likelihood of mother into‐the‐face. In moments when the dyad was engaged in infant‐initiated shared attention, mother into‐the‐face was less likely. This work documents bi‐directional contingencies in the regulation of maternal intrusion and infant behavior during face‐to‐face play at 12 months. We suggest that mother into‐the‐face behavior disturbs an aspect of the infant's experience of recognition.     

Evaluating the Nature of the Still‐Face Effect in the Double Face‐to‐Face Still‐Face Paradigm Using Different Comparison Groups

The current study explored two possible comparison groups for the double Face‐to‐Face Still‐Face (FFSF) paradigm to evaluate their effects on infant behavior and different hypotheses about the nature of the Still‐Face (SF) effect, an effect not fully understood. Mothers and their 4‐month‐old infants were randomly assigned to one of three groups, a double FFSF group (Group_FFSF, n = 44), a control, semi‐structured play group (Group_Story, n = 46), or a control, unstructured play group (Group_Play, n = 28). As hypothesized, Group_FFSF infants exhibited the classic SF response (decreased positive affect and gaze to mother; increased negative affect) and Group_Play infants showed an increase in negative affect over episodes. Contrary to expectations, Group_Story infants displayed a similar, but less intense, pattern of behavior as Group_FFSF. Taken together, the findings indicate that multiple episodes of face‐to‐face play exceeded 4‐month‐olds' regulatory capacities and that infants are sensitive to shared communicative intentions and violations of social expectations, whether these violations are negative or positive in nature.