Infant Behavior & Development最新文献

This study investigated if non-nutritive suck (NNS) at 3 months is related to subsequent oral motor and motor skills using caregiver-reported scores on the Child Oral and Motor Proficiency Scale (ChOMPS) at 12 months in a cohort of 69 full-term infants and their caregivers. Longer NNS burst durations were associated with lower oral motor coordination and total ChOMPS scores. More NNS cycles per minute was associated with lower complex motor movement scores. More NNS bursts, cycles per burst, and cycles per minute were related with lower total ChOMPS scores. Early NNS outcomes can provide valuable insight in future neuromotor development.

In the current preregistered study, we tested n = 67 6-month-old Norwegian infants’ discrimination of a native vowel contrast /y-i/ and a non-native (British) vowel contrast /ʌ-æ/ in an eye-tracking habituation paradigm. Our results showed that, on a group level, infants did not discriminate either contrast. Yet, exploratory analyses revealed a negative association between infants’ performance in each experiment, that is, better discrimination of the native contrast was associated with worse discrimination of the non-native contrast. Potentially, infants in this study might have been on the cusp of perceptual reorganisation towards their native language.

Young infants can discriminate many non-native sounds, but the discrimination ability is thought to decrease within the first year of life due to perceptual attunement. However, most studies tested infants’ perception cross-sectionally, without examining within-group change. To this end, the current study tested German infants’ discrimination of the English /æ/-/ɛ/ contrast both cross-sectionally and longitudinally using the visual habituation technique. In Experiment 1, 96 German-learning infants were tested cross-sectionally at 5–6, 8–9 and 12–13 months. Linear mixed-effects models revealed that while the 5–6-month-olds did not discriminate the contrast, the 8–9- and 12–13-month-olds showed signs of discrimination only when they were habituated with /ɛ/, in line with previous findings suggesting that changes from central to peripheral vowels in the F1/F2 vowel space are more noticeable than in the reverse direction. Moreover, the 8–9-month-olds showed a novelty preference, while the 12–13-month-olds showed a familiarity preference. In Experiment 2, the infants tested at 5–6 months in Experiment 1 were tested again at 8–9 and 12–13 months. Fifteen infants completed the three experiments. Here, only the 12–13-month-olds discriminated the contrast by showing a novelty preference but only when habituated with /æ/. Overall, both experiments showed gradual development of discrimination ability across the first year, which challenges the assumptions of perceptual attunement. We propose that the perceptual sensitivity for a non-native vocalic contrast can improve during development. The change in perceptual asymmetry tells us that the direction of asymmetry is not universal and can be altered by linguistic experience. The change from novelty to familiarity preference may be due to the emerging preference for the more native-like vowel as well as the effect of repeating experiments with the same infants. In sum, our cross-sectional and longitudinal results overlap broadly, but the potential effect of repeating experiments must be considered when interpreting longitudinal studies.

Positive mother-infant interactions are important for infant development. Both mother and infant characteristics, such as maternal depression and infant temperamental negative affect are risk factors for adverse mother-infant bonding and infant outcomes. Although these predictors have been researched individually, limited studies have considered them in concert. This study aimed to examine the role of infant age (6-, 9- and 12-months), infant temperamental negative affect, and maternal depression on maternal and infant social positive engagement during the Still-Face procedure. Participants were 85 ethnically-varied mother-infant dyads (44 % girls). Mothers responded to questionnaires, prior to attending the laboratory for the Still-Face procedure (i.e., a task involving a social stressor). Results showed a significant moderating relationship between infant age, infant temperamental negative affect, and maternal depression on infant social positive engagement. For 12-month-old infants, higher infant temperamental negative affect was found to be compounded by greater maternal depression symptoms resulting in significantly lower social positive engagement following a social stressor. This relationship was not found for younger infants. No predictors were associated with maternal social positive engagement. Results from this study contribute to the literature on infant wellbeing. Results highlight the importance of interventions that aim to reduce maternal depression symptoms, especially, as maternal depression may disproportionately influence 12-month-old infants who have negative temperament.

Classic attachment theory emphasizes the sensitivity of the parent to perceive and appropriately respond to the infant’s cues. However, parent-child attachment is a dyadic interaction that is also dependent upon the sensitivity of the child to the early caregiving environment. Individual differences in infant sensitivity to parental cues is likely shaped by both the early caregiving environment as well as the infant’s neurobiology, such as perceptual sensitivity to social stimuli. Here, we investigated associations between maternal postpartum depression and infant neurological sensitivity to affective touch using brain signal entropy – a metric of the brain’s moment-to-moment variability related to signal processing. We recruited two independent samples of infants aged 0–5 months. In Sample 1 (n = 79), we found increased levels of maternal postpartum depression were associated with diminished perceptual sensitivity – i.e. lower entropy – to affective tactile stimulation specifically within the primary somatosensory cortex. In Sample 2 (n = 36), we replicated this finding and showed that this effect was not related to characteristics of the touch administered during the experiment. These results suggest that decreased affective touch early in life – a common consequence of postpartum depression – likely impacts the infant’s perceptual sensitivity to affective touch and ultimately the formation of experience-dependent neural networks that support the successful formation of attachment relationships.

This study investigates the sensory processing of typically developing toddlers with and without sleep problems. The research group consisted of typically developing toddlers with sleep problems (n = 110, mean age=18.35 ± 3.4 months), while the control group included typically developing toddlers without sleep problems (n = 110, mean age=18.67 ± 3.5 months) and their mothers. Toddlers were assigned to the research and control groups based on their sleep problems, as determined by the Brief Infant Sleep Questionnaire. The sensory processing of the toddlers was evaluated using the Infant/Toddler Sensory Profile 2. Sensory patterns and sensory processing sub-parameters of the research and control groups were compared. The sensory processing of the research group showed atypical behavioral responses in low registration (low awareness or indifferent attitude to sensory stimuli), sensory sensitivity (distracted or irritable attitude, intensely stimulated by sensory stimuli), and sensory avoiding (intentional avoidance of sensory stimuli or attitudes that produce out-of-norm responses) patterns compared to the control group (p < 0.05). Behavioral responses were similar in the sensory seeking (disturbing or dangerous attitude to the environment in search of sensory stimuli) pattern (p > 0.309). Statistically significant differences were observed in all sub-parameters of sensory processing compared to the control group. Our findings indicate that toddlers with sleep problems are at risk for sensory processing issues. Toddlers with sleep problems exhibit atypical sensory responses related to sensory sensitivity, low registration, and sensory avoiding. It should be considered that toddlers with sleep problems may show sensitivity to different sensory stimuli, avoidance or may not be able to recognize sensory stimuli. These findings suggest that the inclusion of sensory profile assessments in interdisciplinary care for toddlers with sleep problems may contribute to parent-infant well-being.

Any experiment brings about results and conclusions that necessarily have a component of uncertainty. Many factors influence the degree of this uncertainty, yet they can be overlooked when drawing conclusions from a body of research. Here, we showcase how subjective logic could be employed as a complementary tool to meta-analysis to incorporate the chosen sources of uncertainty into the answer that researchers seek to provide to their research question. We illustrate this approach by focusing on a body of research already meta-analyzed, whose overall aim was to assess if human infants prefer prosocial agents over antisocial agents. We show how each finding can be encoded as a subjective opinion, and how findings can be aggregated to produce an answer that explicitly incorporates uncertainty. We argue that a core feature and strength of this approach is its transparency in the process of factoring in uncertainty and reasoning about research findings. Subjective logic promises to be a powerful complementary tool to incorporate uncertainty explicitly and transparently in the evaluation of research.

Background

Positive affect synchrony, or the reciprocal exchange of positive affect during free play, can scaffold infants’ socioemotional development. However, parental stress may compromise the expression and exchange of positive affect within families. The current study assesses whether parenting stress and hair cortisol are associated with positive affect synchrony during a triadic play interaction.

Method

Within 70 different-sex dyads consisting of first-time parents and their six-month-old infants who participated in a four-minute laboratory-based free-play task, facial affect of each member of the triad was observationally microcoded at the second-by-second level. Hair samples were collected from mothers and fathers for cortisol assay, and parents completed a self-report measure of parenting stress.

Results

Using dynamic structural equation modeling (DSEM), we found positive between-level and within-level affect synchrony across all family members, with one exception: infants’ affect did not predict fathers’ affect at the following timepoint. Mother-to-infant affect synchrony was greater in mothers with higher hair cortisol. Similarly, mothers with higher parenting stress tended to have greater infant-to-mother affect synchrony, and had infants that displayed less overall positive affect across the interaction.

Conclusion

We found evidence for bidirectional, time-lagged synchrony in the momentary positive affect of mothers, fathers, and infants. Maternal hair cortisol concentration and parenting stress seem to increase affect synchrony between mothers and infants– suggesting that parental stress may correlate with greater affective attunement, but less overall positive affect in infants.

Language development during the 1st year of life is characterized by perceptual attunement: following language-general perception, a decline in the perception of non-native phonemes and a parallel increase in or maintenance of the perception of native phonemes. While this general pattern is well established, there are still many gaps in the literature. First, most evidence documenting these patterns comes from “Minority world countries” with only a limited number of studies from “Majority world countries”, limiting the range of languages and contrasts assessed. Second, few studies test both the developmental patterns of native and non-native speech perception in the same group of infants, making it hard to draw conclusions on simultaneous decline in non-native and increase in native speech perception. Such limitations are in part due to the effort that goes into testing developing speech sound perception, where usually only discrimination of one contrast per infant can be tested at a time. The present study thus set out to assess the feasibility of assessing a given infant on their discrimination of two speech sound contrasts during the same lab visit. It leveraged the presence of documented patterns of the improvement of native and the decline of non-native phoneme discrimination abilities in Japanese, therefore assessing native and non-native speech perception in Japanese infants from 6 to 12 months of age. Results demonstrated that 76 % of infants contributed discrimination data for both contrasts. We found a decline in non-native speech perception evident in discrimination of the non-native /ɹ/-/l/ consonant contrast at 9–11, but not at 11–13 months of age. Additionally, a parallel increase in native speech perception was demonstrated evident in an absence of native phonemic vowel length discrimination at 6–7 and 9–11 months and a discrimination of this contrast at 11–13 months of age. These results, based on a simultaneous assessment of native and non-native speech perception in Japanese-learning infants, demonstrate the feasibility of assessing the discrimination of two contrasts in one testing session and corroborate theoretical proposals on two hallmarks of perceptual attunement: a decrease in non-native and a facilitation in native speech perception during the first year of life.