Infancy最新文献

Adult studies have shown that observed interpersonal touch provides crucial information about others' emotional states. Yet, despite the unique communicative function of touch during development, very little is known about infants' sensitivity to the emotional valence of observed touches. To investigate this issue, we measured facial electromyographic (EMG) activity in response to positive (caress) and negative (scratches) observed touches in a sample of 11-month-old infants. Facial EMG activity was measured over the zygomaticus major (ZM) and corrugator supercilii muscles, respectively involved in positive (i.e., smiling) and negative (i.e., frowning) facial expressions. Results have shown distinct activations of the ZM during the observation of scratches and caresses. In particular, significantly greater activation of the ZM (smiling muscle) emerged specifically in response to the observation of caresses compared to scratches. Our finding suggests that, in infancy, observed affective touches can evoke emotional facial reactions.

Toddlers prefer to learn from familiar adults, particularly their caregivers, and perform better on word learning tasks when taught by caregivers than by strangers. However, it remains unclear why toddlers learn better from caregivers than from strangers. One possibility is that toddlers are more receptive to learning from individuals whom they have found to be engaging in previous interactions. The current study tested whether toddlers learn more from an unfamiliar adult who was previously engaging than from an unfamiliar adult who was previously unengaging. Toddlers (27–29 months, N = 40) were taught labels for novel objects by two different experimenters. Prior to word learning, toddlers watched pre-recorded videos of one experimenter utilizing engaging behaviors (i.e., using infant-directed speech, gestures, eye contact, and positive affect) and one experimenter utilizing unengaging behaviors (i.e., using adult-directed speech, no gestures, no eye contact, and neutral affect). Both experimenters were equally engaging during labeling. Word learning was then tested using a looking-while-listening paradigm. The results of linear mixed-effects model, cluster-based permutation, and growth curve analyses suggest heightened performance for words that were taught by the experimenter who was previously engaging. These results begin to reveal the kinds of social experiences that promote success in early word learning.

Cognitive control is a predictor of later-life outcomes and may underpin higher order executive processes. The present study examines the development of early cognitive control during the first 24-month. We evaluated a tablet-based assessment of cognitive control among infants aged 18- and 24-month. We also examined concurrent and longitudinal associations between attentional disengagement, general cognitive skills and cognitive control. Participants (N = 60, 30 female) completed the tablet-task at 18- and 24-month of age. Attentional disengagement and general cognitive development were assessed at 5-, 8-, 12-, 18- and 24-month using an eye-tracking measure and the Mullen Scales of Early Learning (MSEL), respectively. The cognitive control task demonstrated good internal consistency, sensitivity to age-related change in performance and stable individual differences. No associations were found between infant cognitive control and MSEL scores longitudinally or concurrently. The eye-tracking task revealed that slower attentional disengagement at 8-month, but faster disengagement at 18-month, predicted higher cognitive control scores at 24-month. This task may represent a useful tool for measuring emergent cognitive control. The multifaceted relationship between attention and infant cognitive control suggests that the rapid development of the attentional system in infancy results in distinct attentional skills, at different ages, being relevant for cognitive control development.

This study aimed to assess which action component (movement or goal) infants prioritize in their imitation behavior when they get information about its relevance from two important sources: perceptual goal saliency and experimenter's verbal information. 16- to 18-month-olds (N = 72) observed how the experimenter moved a toy mouse with a hopping or sliding movement onto one of two empty spaces (low goal saliency) or 2D circles (medium saliency), or inside one of two 3D houses (high saliency). Before the demonstration, the experimenter verbally announced the movement style or the goal. Results showed that verbal action descriptions did not influence infants' imitation. However, matching previous findings, infants imitated the goal more often than the movement in the high-saliency condition, and the movement more often than the goal in the low-saliency condition. Moreover, in the novel medium-saliency condition, infants imitated both components equally often. Thus, selective imitation varied as a function of perceptual goal saliency, but not of verbal cues. This suggests that perceptual features can enhance infants' bottom-up processing and imitation of action components, while the impact of top-down processes based on verbal cues may vary depending on task characteristics and infants' verbal abilities, inducing a need for further research.

It is well established that infants use various cues to find words within fluent speech from about 7 to 8 months of age. Research suggests that two main mechanisms support infants' speech segmentation: prosodic cues like the word stress patterns, and distributional cues like transitional probabilities (TPs). We tested 6-month-old German-learning infants' use of prosodic and statistical cues for speech segmentation in three experiments. In Experiment 1, infants were familiarized with an artificial language string where TPs signaled either word boundaries or iambic words—a stress pattern that is disfavored in German. Experiment 2 was a control and only the test phase was presented. In Experiment 3, prosodic cues were absent in the string and only TPs signaled word boundaries. All experiments included the same conditions at test: disyllabic words with high TPs in the string, words with low TPs and words with non-co-occurring syllables. Results showed that infants relied more strongly on prosodic cues than on TPs for word segmentation. Notably, no segmentation evidence emerged when prosodic cues were absent in the string. This finding underlines early impacts of language-specific structural properties on segmentation mechanisms.

Background television has been found to negatively impact children's language development and self-regulatory skills, possibly due to decreased parent-child interactions. Most of the research on the relationship between background TV and caregiver-child interactions has been conducted in laboratory settings. In the current study, we conducted home observations and investigated whether infants engage in fewer interactions with family members in homes where background TV is more prevalent. We observed 32 infants at the ages of 8, 10, and 18 months in their home environments, coding for dyadic interactions (e.g., parent talking to and/or engaging with the child), triadic interactions (e.g., parent and infant play with a toy together), and infants' individual activities. Our findings revealed that background TV was negatively associated with the time infants spent in triadic interactions, positively associated with time spent engaging in individual activities, and not significantly related to the time spent in dyadic interactions. Apart from the relationship between background TV and individual activity time at 8 months, these associations remained significant even after accounting for families' socioeconomic status. These findings imply a correlation between background TV exposure and caregiver-infant-object interactions, warranting a longitudinal analysis with larger sample sizes.

Turn-taking interactions are foundational to the development of social, communicative, and cognitive skills. In infants, vocal turn-taking experience is predictive of infants' socioemotional and language development. However, different forms of turn-taking interactions may have different effects on infant vocalizing. It is presently unknown how caregiver vocal, non-vocal and multimodal responses to infant vocalizations compare in extending caregiver-infant vocal turn-taking bouts. In bouts that begin with an infant vocalization, responses that maintain versus change the communicative modality may differentially affect the likelihood of further infant vocalizing. No studies have examined how caregiver response modalities that either matched or differed from the infant acoustic (vocal) modality might affect the temporal structure of vocal turn-taking beyond the initial serve-and-return exchanges. We video-recorded free-play sessions of 51 caregivers with their 9-month-old infants. Caregivers responded to babbling most often with vocalizations. In turn, caregiver vocal responses were significantly more likely to elicit subsequent infant babbling. Bouts following an initial caregiver vocal response contained significantly more turns than those following a non-vocal or multimodal response. Thus prelinguistic turn-taking is sensitive to the modality of caregivers' responses. Future research should investigate if such sensitivity is grounded in attentional constraints, which may influence the structure of turn-taking interactions.

When infants start mastering their first language, they may start to notice when words are used incorrectly. Around 14-months of age, infants detect incorrect labeling when they are presented with an object which is labeled while still visible. However, things that are referred to are often out of sight when we communicate about them. The present study examined infants' detection of semantic mismatch when the object was occluded at the time of labeling. Specifically, we investigated whether mislabeling that referred to an occluded object could elicit a semantic mismatch. We showed 14-month-old Danish-speaking infants events where an onscreen agent showed an object and then hid it in a box. This was followed by another agent's hand pointing at the box, and a concurrent auditory category label played, which either matched or did not match the hidden object. Our results indicate that there is an effect of semantic mismatch with a larger negativity in incongruent trials. Thus, infants detected a mismatch, as indicated by a larger n400, when occluded objects were mislabeled. This finding suggests that infants can sustain an object representation in memory and compare it to a semantic representation of an auditory category label.

Parents use joint attention to direct infants to environmental stimuli. We hypothesized that infants whose parents provide more bids for joint attention will display a more complex neural response when viewing social scenes. Sixty-one 8-month-old infants underwent electroencephalography (EEG) while viewing videos of joint- and parallel-play and participated in a free play interaction. EEG data was analyzed using multiscale entropy, which quantifies neural variability. Free play interactions assessed parent alternating gaze, a behavioral mechanism for directing attention to environmental cues. We found a significant positive association between parent alternating gaze and neural entropy in frontal and central regions. These results suggest a relationship between parent behavior and infant neural mechanisms that regulate social attention, underlying the importance of parental cues in forming neural networks.

Caregivers are instrumental in the development of infant emotion regulation; however, few studies have focused on delineating the real-time effectiveness of strategies that caregivers use to reduce infant distress. It is also unclear whether certain caregiver traits facilitate engagement in more successful regulation strategies. This study addressed these gaps by: (1) examining the differential effectiveness of maternal regulatory attempts (MRAs; behavioral strategies initiated by mothers to assist infants with regulating emotional states) in reducing 12- to 24-month-old infants' frustration during a toy removal task; and (2) assessing whether maternal mind-mindedness (mothers' attunement to their infant's mental state) predicted mothers' selection of MRAs. Multilevel modeling revealed that distraction and control were the most effective MRAs in reducing infant negative affect across 5-s intervals (N = 82 dyads; M infant age = 18 months; 45 females). Greater use of non-attuned mind-related speech predicted less engagement in effective MRAs, supporting a link between caregivers' socio-cognitive skills and provision of in-the-moment regulation support. These findings highlight the value of considering caregiver regulatory behaviors as a target for elucidating how maternal socialization of emotion regulation occurs in real-time. They also underscore mothers' important role as socializing agents in the development of this foundational developmental ability.