Infancy最新文献

High-quality early care and education (ECE) programs are associated with positive outcomes, especially for children from low-income families. During the initial COVID-19 pandemic lockdown many of these families faced an abrupt halt to ECE. Here, we examined how toddlers from economically disadvantaged backgrounds enrolled in high-quality ECE programs in the United States during the 2020 pandemic (n = 48) fared on cognitive and socioemotional outcomes compared to a 2019 pre-pandemic cohort (n = 94) and a pandemic 2021 cohort (n = 132). Toddlers in the 2020 cohort scored significantly lower on executive function compared to toddlers in 2019 and 2021 cohorts. Toddlers in the 2020 cohort had higher ratings self-regulation compared to the pre-pandemic cohort, but not 2021 cohort. There were no differences on attachment ratings between cohorts. Findings suggest that the abrupt halt to ECE programs due to the COVID-19 pandemic impacted US toddlers’ cognitive and socioemotional abilities. This underscores the importance of continued high-quality ECE for infants and toddlers from low-income families during disruptive times. Further work is needed to investigate the long-term impacts of experiencing an abrupt halt to ECE due to COVID-19.

Young infants' face perception capabilities quickly tune to the features of their primary caregiver. The current study examines whether infants distinguish faces in a more conceptual manner using a manual-search, violation of expectation task that has previously been used to test kind-based individuation. We tested how well infants between 11 and 27 months of age individuated faces that varied by superordinate category (human vs. non-human in Experiment 1) subordinate category (individual identity in Experiment 2) or by race (White vs. Black, Experiments 1 & 2). We assessed individuation by quantifying the difference in infants' duration of reaching within an empty box between trials when the box was unexpectedly empty and expectedly empty. We found evidence of individuation across all ages and conditions, but with within-infant variation. On average, infants individuated face from non-face stimuli (Experiment 1), individual face identities (Experiment 2), and White versus Black faces (Experiments 1 & 2). These findings suggest that 1- to 2-year-old infants use distinct human face features to represent individuals across time and space. We discuss this evidence for race-based individuation and related complexities of face identity in terms of implications for conceptual development for faces in the first years of life.

This study investigates attention modulation as a function of infant directed (ID) versus adult directed (AD) speech in seven-month-old infants using electroencephalographic measures. In three experiments, infants were presented with either ID speech or AD speech as stimuli, followed by highly variable images of inanimate objects as targets. In Experiment 1 (N = 18), images were preceded by ID or AD speech with semantic content (“Look here”). Contrary to hypothesis, targets preceded by AD speech elicited increased amplitude of the Negative central (Nc) component compared to targets preceded by ID speech, indicating increased attention. Experiment 2 (N = 23) explored whether ID versus AD speech influences attention allocation also without semantic content. The same targets were either preceded by human voice sounds without semantic content (“Uh-Ah”) following the prosody of either ID or AD speech register. No differences in attention allocation or object processing were observed. Experiment 3 (N = 18) contrasted ID speech with and without semantic content and found enhanced attention allocation following stimuli without semantic content, but increased object processing following stimuli with semantic content. Overall, the effects observed here are consistent with the idea that less familiar speech stimuli increase attention for subsequent objects. Semantic content of stimuli increased the depth of object processing in 7-month-olds.

What environmental regularities support infant communicative learning from social interactions? We propose that infants allocate their attention toward and learn from external events that are contingent on their own behaviors. We tested the robustness of the influence of contingency on communicative learning by using a non-biological stimulus, a remote-controlled car, as the social partner. The car approached infants and produced a speech sound either contingently to infants' vocalizations or on a yoked schedule. Two additional groups had an unfamiliar human experimenter as their social partner in contingent and yoked control conditions. We assessed whether infants formed expectations about their partner's responsiveness to their vocalizations. Expectations made based on contingent responsiveness would support the role of contingency in promoting plasticity in early communicative learning. Infants across all conditions increased their vocalization rates when their partner paused in responding, suggesting that they expected their vocalizations to influence their partners' behavior. Infants vocalized significantly more to the social partner than their caregiver if they received contingent rather than yoked responses from the social partner, regardless of if the partner was a human or non-biological agent. Contingent responses to prelinguistic vocalizations facilitated the formation of expectations for interactivity of social partners.

Daylong recordings provide an ecologically valid option for analyzing language input, and have become a central method for studying child language development. However, the vast majority of this work has been conducted in North America. We harnessed a unique collection of daylong recordings from Slovenian infants (age: 16–30 months, N = 40, 18 girls), and focus our attention on manually annotated measures of parentese (infant-directed speech with a higher pitch, slower tempo, and exaggerated intonation), conversational turns, infant words, and word combinations. Measures from daylong recordings showed large variation, but were comparable to previous studies with North American samples. Infants heard almost twice as much speech and parentese from mothers compared to fathers, but there were no differences in language input to boys and girls. Positive associations were found between the social-interactional features of language input (parentese, turn-taking) and infants' concurrent language production. Measures of child speech from daylong recordings were positively correlated with measures obtained through the Slovenian MacArthur-Bates Communicative Development Inventory. These results support the notion that the social-interactional features of parental language input are the foundation of infants' language skills, even in an environment where infants spend much of their waking hours in childcare settings, as they do in Slovenia.

Caregivers may perceive pointing as an indication of infants' readiness to learn, thereby increasing their tendency to label objects regardless of the infant's gesture type and context. This was investigated in this study by tracking 35 infants at home at the ages of 11 and 13 months and observing their interactions with their mothers during object manipulation. We focused on four types of communicative gestures: typical giving gestures, gestures contingent on exploration, gestures contingent on play, and pointing. We analyzed maternal response tendencies, including affirmation, naming, discourse, and pretense. The results revealed that when infants reached the age of 13 months, they tripled their pointing production; in turn, the maternal response changed entirely, with naming becoming the preferred response to all types of gestures. Furthermore, when infants were 13 months old and offered an object contingent on play acts, mothers increased their pretense acts sevenfold. Based on the most informative responses to infants among those examined, we argue that an increase in the number of pointing gestures may gradually be associated with the establishment of the maternal perception that an infant is ready to learn and a subsequent increase in naming and pretense production by the mother.

Infants' use of pointing gestures to direct and share attention develops during the first 2 years of life. Shyness, defined as an approach-avoidance motivational conflict during social interactions, may influence infants’ use of pointing. Recent research distinguished between positive (gaze and/or head aversions while smiling) and non-positive (gaze and/or head aversions without smiling) shyness, which are related to different social and cognitive skills. We investigated whether positive and non-positive shyness in 12-month-old (n = 38; 15 girls) and 15-month-old (n = 45; 15 girls) infants were associated with their production of pointing gestures. Infants' expressions of shyness were observed during a social-exposure task in which the infant entered the laboratory room in their parent's arms and was welcomed by an unfamiliar person who provided attention and compliments. Infants' pointing was measured with a pointing task involving three stimuli: pleasant, unpleasant, and neutral. Positive shyness was positively associated with overall pointing at 15 months, especially in combination with high levels of non-positive shyness. In addition, infants who displayed more non-positive shyness pointed more frequently to direct the attention of the social partner to an unpleasant (vs. neutral) stimulus at both ages. Results indicate that shyness influences the early use of pointing to emotionally charged stimuli.

Memory develops across the course of the first years of life and is influenced by daily experiences, such as exposure to media like books and television. Memory as tapped by Deferred imitation (DI) requires that toddlers form a representation of the target actions that they can later use to reproduce the actions and in addition to measuring memory for real live events, it can also be used to measure memory for events viewed through media. Toddlers are frequently exposed to multiple forms of digital media in addition to more traditional forms of picture book reading. In a within-subjects design, memory was assessed with a DI task in 2-year-olds (n = 89) using the Frankfurt Imitation Test. Deferred imitation was assessed after live and video demonstrations. Parents completed a survey about children's media use. Picture book reading for less than 30 min a day predicted lower memory scores for actions demonstrated live. Watching video content for more than 1 h a day predicted lower memory scores for actions demonstrated on video. Results are interpreted in terms of individual differences in experiences of traditional and digital media and the development of symbolic understanding.

Mother-infant interactions are co-regulated and provide the foundation for mother-infant relationship quality. The implications of maternal depression and contextual demands (i.e., reinstating the interaction following maternal unavailability and vocalized infant distress) on observationally coded co-regulation in mother-infant dyads (n = 40) at 4-months was investigated. Associations among co-regulation patterns and mother-infant relationship quality was also examined. Dyads participated in Still-Face (SF) and Separation (SP) procedures, with periods of maternal emotional and physical unavailability. Co-regulation was captured using the Revised Relational Coding System. Relationship quality was examined using the Emotional Availability Scales. Dyads in the depressed group had significantly more unilateral exchanges than the non-depressed group following the SF and SP perturbations. The depressed group also had significantly more distress vocalizations during the SP perturbation than the non-depressed group. Co-regulation in the depressed group was less disrupted by the SF perturbation. Positive relationship quality dimensions (maternal sensitivity, structuring, and infant responsiveness) were associated with more symmetrical and less unilateral co-regulation regardless of the interaction period. There were also context-specific results pertaining to patterns of co-regulation and associated maternal hostility and infant responsiveness. Results highlight co-regulatory differences in depressed mothers and their infants and how these differences are exacerbated by contextual demands.

Turn-taking is a universal pattern of human conversations characterized by a fast exchange of turns between speakers and an avoidance of overlaps. Language is embedded in this conversational skill acquired well before it during infancy, through everyday interactions with caregivers. The earliness of this skill and its link with language allows us to test whether social environment shapes early language development. We therefore study turn-taking perception of 6-month-old infants by measuring their gazes during video presentation of three different conversational situations where the turn is explicitly given, normally taken or taken with an overlap. We studied 51 infants to cover several family and infant characteristics: infants' sex, presence of siblings, and family socioeconomic status (SES). We found that infants looked more at the second speaker when she overlapped the first speaker than in the other situations, but not all infants were equally sensitive. Indeed, infants from high-SES families reacted differently to the three situations, while infants from the two lower SES categories did not. Also, only singletons reacted differently by looking more at the second speaker after the overlapping and turn-giving situations, and not after the turn-taking situation. Our results emphasize the importance of early social experiences on language development.