Sensitivity to Confidence Cues Increases during the Second Year of Life

We investigated the emergence in infancy of a preference to imitate individuals who display confidence over lack of confidence. Eighteen‐ and 24‐month‐olds (N = 70) were presented with an experimenter who demonstrated the use of several objects accompanied by either nonverbal expressions of confidence or lack of confidence. At 24 months, infants were more likely to imitate the actions when demonstrated by a confident experimenter than by an unconfident experimenter; 18‐month‐olds showed no such preference. The experimenter then presented an additional imitation trial and a word‐learning trial while displaying a neutral expression. Twenty‐four‐month‐olds persisted in preferentially imitating a previously confident experimenter, but prior confidence had no effect on their word learning. These findings demonstrate a developmental increase in infants’ use of confidence cues toward the end of the second year of life.     

Preference for Dynamic Human Images and Gaze‐Following Abilities in Preterm Infants at 6 and 12 Months of Age: An Eye‐Tracking Study

Preterm children are reported to be at higher risk of social communication problems such as autism spectrum disorder compared with full‐term infants. Although previous studies have suggested that preference for social stimuli in infancy is a possible indicator of later social communication development, little is known about this relation in preterm infants. We examined the gaze behavior of low‐risk preterm and full‐term infants at 6 and 12 months' corrected ages using two types of eye‐tracking tasks, which measured 1) preference for social stimuli by biological motion and human geometric preference and 2) ability to follow another's gaze direction. We found that preterm (compared with full‐term) infants at both 6 and 12 months of age spent less time looking toward dynamic human images, followed another's gaze less frequently, and looked for a shorter time at an object cued by another. Moreover, we found a positive correlation between looking time toward dynamic human images and frequency of gaze following at 12 months of age in full‐term, but not preterm, infants. We discuss the relation between the atypical patterns of gaze behavior in preterm infants and their higher risk of later social communication problems.     

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.     

Intersensory Redundancy and 7‐Month‐Old Infants' Memory for Arbitrary Syllable‐Object Relations

Seven‐month‐old infants require redundant information, such as temporal synchrony, to learn arbitrary syllable‐object relations (Gogate & Bahrick, 1998). Infants learned the relations between 2 spoken syllables, /a/ and /i/, and 2 moving objects only when temporal synchrony was present during habituation. This article presents 2 experiments to address infants' memory for these relations. In Experiment 1, infants remembered the syllable‐object relations after 10 min, only when temporal synchrony between the vocalizations and moving objects was provided during learning. In Experiment 2, 7‐month‐olds were habituated to the same syllable‐object pairs in the presence of temporal synchrony and tested for memory after 4 days. Once again, infants learned and showed emerging memory for the syllable‐object relations 4 days after original learning under the temporally synchronous condition. These findings are consistent with the view that prior to symbolic development, infants learn and remember word‐object relations by perceiving redundant information in the vocal and gestural communication of adults.     

Emergence of Selective Social Referencing in Infancy

Seven and 10‐month‐old infants were presented with a remote‐controlled toy dog that intermittently barked at 30‐sec intervals as they faced an experimenter who either attended to them (look toward condition) or looked away (look away condition). Seven‐month‐old infants' looking toward the experimenter was significantly greater after the dog barking events compared to before regardless of experimental condition. In contrast, 10‐month‐old infants' looks were significantly greater after the barking events compared to before only when the experimenter was attending to them. These results suggest that by 10 months infants monitor and refer to people in an ambiguous situation depending on their attention toward them. This development is viewed as indexing the emergence of an intentional stance in social referencing by 10 months of age.     

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.     

Evaluation of the Psychometric Properties of the Gap‐Overlap Task in 10‐Month‐Old Infants

Understanding the development of attention is key to understanding cognitive maturation. The gap‐overlap task can be administered at all ages and is widely used to study the development of overt visual attention. However, studies using the gap‐overlap task report different measures and little is known about the tasks’ psychometric properties, especially in infants. We tested the 1‐week test–retest reliability of two frequently used gap‐overlap measures of attentional disengagement in 10‐month‐old infants; the gap effect as measured by the difference between the gap and overlap condition and the gap effect as measured by the difference between the gap and baseline condition. Sixty‐seven infants performed the gap‐overlap task twice, of which 45 infants had sufficient data quality for further analyses. Test–retest reliability of the overlap‐gap gap effect was higher (r = .50) than the baseline‐gap gap effect (r = .29). Moreover, the shared variance between overlap and baseline saccadic reaction times was moderate to high across sessions. In light of these results and the methodological challenges and limitations of infant research, we consider the overlap‐gap gap effect to be a good measure to study the development of attentional disengagement in infants and suggest the exclusion of the baseline condition in future studies.     

Social motivation predicts gaze following between 6 and 14 months

Infants vary in their ability to follow others’ gazes, but it is unclear how these individual differences emerge. We tested whether social motivation levels in early infancy predict later gaze following skills. We longitudinally tracked infants’ (N = 82) gazes and pupil dilation while they observed videos of a woman looking into the camera simulating eye contact (i.e., mutual gaze) and then gazing toward one of two objects, at 2, 4, 6, 8, and 14 months of age. To improve measurement validity, we used confirmatory factor analysis to combine multiple observed measures to index the underlying constructs of social motivation and gaze following. Infants’ social motivation—indexed by their speed of social orienting, duration of mutual gaze, and degree of pupil dilation during mutual gaze—was developmentally stable and positively predicted the development of gaze following—indexed by their proportion of time looking to the target object, first object look difference scores, and first face-to-object saccade difference scores—from 6 to 14 months of age. These findings suggest that infants’ social motivation likely plays a role in the development of gaze following and highlight the use of a multi-measure approach to improve measurement sensitivity and validity in infancy research.     

Looking Behavior at Test and Relational Memory in 6‐Month‐Old Infants

Small‐scale eye‐tracking research lends support to behavioral studies of relational memory by 6 months of life. Here, in the largest eye‐tracking test of relational memory to date (n = 276), we replicate these findings and examine the impact of excluding data based on looking behavior characteristics at test. Past work examining infants' preferential looking toward arbitrary‐paired objects and scenes has excluded infants from analysis based upon “insufficient looking” at test. Yet, research suggests that variation in looking behavior may be associated with looking patterns during encoding, as well as trait‐like differences in visual and cognitive processing. Similar to past research, we observed evidence for relational memory among 6‐month‐olds. In keeping with past research, when infants were excluded based on “insufficient looking,” we observed evidence for relational memory only when infants were tested immediately. However, when exclusion criteria were relaxed, infants specifically demonstrated preferential looking during a presumably more difficult delay‐plus‐interference condition. Moreover, analyses revealed that looking behavior during encoding was associated with looking behavior at test. Together, results suggest that infants do possess rudimentary relational memory capabilities, but that experimenters' ability to detect these capabilities is influenced by both experimental conditions and individual differences in looking behavior.     

Social interaction targets enhance 13-month-old infants' associative learning

Infants are attentive to third-party interactions, but the underlying mechanisms of this preference remain understudied. This study examined whether 13-month-old infants (N = 32) selectively learn cue–target associations guiding them to videos depicting a social interaction scene. In a visual learning task, two geometrical shapes were repeatedly paired with two kinds of target videos: two adults interacting with one another (social interaction) or the same adults acting individually (non-interactive control). Infants performed faster saccadic latencies and more predictive gaze shifts toward the cued target region during social interaction trials. These findings suggest that social interaction targets can serve as primary reinforcers in an associative learning task, supporting the view that infants find it intrinsically valuable to observe others’ interactions.     

Walking Ability is Associated with Social Communication Skills in Infants at High Risk for Autism Spectrum Disorder

Achievement of early motor milestones in infancy affords new opportunities for social interaction and communication. Research has shown that both motor and social deficits are observed in infants who later develop autism spectrum disorder (ASD). This study examined associations between motor and Social communication skills in 12‐month‐old infant siblings of children with ASD who are at heightened risk for developmental delays (N = 86) and low‐risk, typically developing infants (N = 113). Infants were classified into one of three groups based on their walking ability: walkers (walks independently), standers (stands independently), or prewalkers (does not yet stand or walk independently). Social communication and cognitive skills were assessed with two standardized assessments (Communication and Symbolic Behaviors Scales [CSBS] and Mullen Scales of Early Learning) and compared across the three walking groups. Results demonstrated that high‐risk walkers showed superior Social communication skills, but commensurate cognitive skills, compared to high‐risk prewalkers. In contrast, Social communication and cognitive skills were largely comparable for low‐risk infants, regardless of walking status. Findings suggest that for high‐risk infants, who are already vulnerable to developmental delays and ASD, independent walking may facilitate the emergence of Social communication abilities. Pivotal motor milestones may serve as useful indicators of Social communication delays and targets for intervention.     

Monolingual and bilingual infants’ word segmentation abilities in an inter‐mixed dual‐language task

Previous studies show that young monolingual infants use language‐specific cues to segment words in their native language. Here, we asked whether 8 and 10‐month‐old infants (N = 84) have the capacity to segment words in an inter‐mixed bilingual context. Infants heard an English‐French mixed passage that contained one target word in each language, and were then tested on their recognition of the two target words. The English‐monolingual and French‐monolingual infants showed evidence of segmentation in their native language, but not in the other unfamiliar language. As a group, the English‐French bilingual infants segmented in both of their native languages. However, exploratory analyses suggest that exposure to language mixing may play a role in bilingual infants’ segmentation skills. Taken together, these results indicate a close relation between language experience and word segmentation skills.     

Behavioral and Electrophysiological Indices of Memory in Typically Developing and Hypoxic‐Ischemic Injured Infants

Behavioral and electrophysiological indices of memory were examined in 12‐month‐old typically developing control infants (CON) and infants with history of perinatal hypoxic‐ischemic injury (HII) across 2 days. Using a visual paired comparison (VPC) procedure, novelty preference was tested immediately after a familiarization period and then after delays of 2 min and 24 h. Both groups showed a significant novelty preference only for the no‐delay condition. On day two, event‐related potentials (ERPs) were recorded while infants viewed the VPC familiar face, a more recently familiarized face, and a novel face, and mean amplitude for components thought to reflect memory (positive slow wave, PSW) and attention (negative central, Nc) were computed. In temporal regions, HII showed a diminished Nc and enhanced PSW to the recently familiarized face, while CON showed a similar trend for the PSW only. Overall, infants showed the largest PSW over left scalp regions. Finally, a positive correlation between VPC novelty preference after 24 h and PSW was found in CON, and preliminary results suggest that this association differs as a function of group. Therefore, in comparison with CON, HII showed both similarities and differences on individual tasks of memory as well as potentially disparate relations between the behavioral and neural mechanisms underlying memory performance.     

Age‐Related Changes in Prosodic Features of Maternal Speech to Prelingually Deaf Infants with Cochlear Implants

This study investigated prosodic and structural characteristics of infant‐directed speech to hearing‐impaired infants as they gain hearing experience with a cochlear implant over a 12‐month period of time. Mothers were recorded during a play interaction with their HI infants (N = 27, mean age 18.4 months) at 3, 6, and 12 months postimplantation. Two separate control groups of mothers with age‐matched normal‐hearing infants (NH‐AM) (N = 21, mean age 18.1 months) and hearing experience‐matched normal‐hearing infants (NH‐EM) (N = 24, mean age 3.1 months) were recorded at three testing sessions. Mothers produced less exaggerated pitch characteristics, a larger number of syllables per utterance, and faster speaking rate when interacting with NH‐AM as compared to HI infants. Mothers also produced more syllables and demonstrated a trend suggesting faster speaking rate in speech to NH‐EM relative to HI infants. Age‐related modifications included decreased pitch standard deviation and increased number of syllables in speech to NH‐AM infants and increased number of syllables in speech to HI and NH‐EM infants across the 12‐month period. These results suggest that mothers are sensitive to the hearing status of their infants and modify characteristics of infant‐directed speech over time.     

Visual short‐term memory for overtly attended objects during infancy

We investigated limitations in young infants’ visual short‐term memory (VSTM). We used a one‐shot change detection task to ask whether 4‐ and 8.5‐month‐old infants (N = 59) automatically encode fixated items in VSTM. Our task included trials that consisted of the following sequence: first a brief (500 ms) presentation with a sample array of two items, next a brief (300 ms) delay period with a blank screen, and finally a test array (2,000 ms) identical to the sample array except that the color of one of the two items is changed. In Experiment 1, we induced infants to fixate one item by rotating it during the sample (the other item remained stationary). In Experiment 2, none of the items rotated. In both experiments, 4‐month‐old infants looked equally at the fixated item when it did and did not change color, providing no evidence that they encoded in VSTM the fixated item. In contrast, 8.5‐month‐old infants in Experiment 1 preferred the fixated item when it changed color from sample to test. Thus, 4‐month‐old infants do not appear to automatically encode fixated items in VSTM.     

Infant Physiological and Behavioral Responses to a Jealousy Provoking Condition

Recent research has demonstrated a relationship between infants' tonic electroencephalogram (EEG) patterns and approach‐style jealousy responses (Mize & Jones, 2012 ). Although it has been found that adults exhibit approach‐style neural activity during jealousy paradigms (Harmon‐Jones, Peterson, and Harris, 2009 ), parallel research on neural activity during a jealousy paradigm in infants is lacking from the literature base. The purpose of the current research is to examine EEG patterns of 35 infants (Mean age = 8.92 months old) in a social‐rival paradigm designed to elicit jealousy responses. Consistent with past research, infants demonstrated more approach‐style, jealousy‐related behaviors when their mothers attended to a social‐rival than to a nonsocial rival. Additionally, infants demonstrated approach‐style anterior EEG activity during the social‐rival condition, a pattern that is associated with jealousy. The current findings suggest that the physiological underpinnings for the emotions that motivate the protection of important dyadic relationships are in place early in ontogeny. Therefore, jealousy‐type behaviors and physiological responses begin to be observable as early as 9‐months‐old when maternal attention is lost to a social‐rival.     

Longitudinal assessment of social attention in preterm and term infants: Its relation to social communication and language outcome

Preterm birth has been reported to be associated with an increased risk of social communication and language problems. Recently, we found that preterm infants showed atypical patterns of social attention compared with term infants. However, it is still unknown how social attention develops and whether the individual differences are associated with developmental outcomes for social communication and language in preterm infants. The social attention of preterm and term infants at 6, 12, and 18 months was investigated using two types of social attention tasks (human-geometric preference task and gaze-following task). The Modified Checklist for Autism in Toddlers (M-CHAT) and the MacArthur Communicative Development Inventory adapted for Japanese were measured at 18 months. We found that compared with term infants, preterm infants spent less time looking toward dynamic human images and followed another's gaze directions less frequently through 6, 12, and 18 months. Moreover, hierarchical multiple regression analysis revealed that less preference for dynamic human images and gaze-following abilities was associated with high M-CHAT and low language scores in preterm and term infants, respectively. These findings suggest that birth status affects development of social attention through 18 months and individual differences in social attention reflect differences in social communication and language outcomes.     

Adult‐Directed and Peer‐Directed Respect for Authority: Relationships With Aggressive and Manipulative Behavior

This study investigated whether respect for adult and peer authority are separate attitudes which have distinct relationships with aggressive and manipulative behavior. Items assessing admiration for and obedience toward parents, teachers, popular students, and friend group leaders were administered to 286 middle school students (M age = 12.6 years). Factor analysis revealed two primary factors which corresponded to adult‐directed and peer‐directed respect orientations. Results suggested that adult‐directed respect was associated with lower levels of aggression and social manipulation, whereas peer‐directed respect was associated with higher levels of these behaviors. The role of peer‐directed respect as a risk factor for negative social behavior in adolescence is discussed.     

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.     

Twelve‐Month‐Olds Understand Social Intentions Based on Prosody and Gesture Shape

Infants infer social and pragmatic intentions underlying attention‐directing gestures, but the basis on which infants make these inferences is not well understood. Previous studies suggest that infants rely on information from preceding shared action contexts and joint perceptual scenes. Here, we tested whether 12‐month‐olds use information from act‐accompanying cues, in particular prosody and hand shape, to guide their pragmatic understanding. In Experiment 1, caregivers directed infants’ attention to an object to request it, share interest in it, or inform them about a hidden aspect. Caregivers used distinct prosodic and gestural patterns to express each pragmatic intention. Experiment 2 was identical except that experimenters provided identical lexical information across conditions and used three sets of trained prosodic and gestural patterns. In all conditions, the joint perceptual scenes and preceding shared action contexts were identical. In both experiments, infants reacted appropriately to the adults’ intentions by attending to the object mostly in the sharing interest condition, offering the object mostly in the imperative condition, and searching for the referent mostly in the informing condition. Infants’ ability to comprehend pragmatic intentions based on prosody and gesture shape expands infants’ communicative understanding from common activities to novel situations for which shared background knowledge is missing.