Infant Attention Research Articles

Regions of variable DNA methylation in human placenta associated with newborn neurobehavior

ABSTRACTThe placenta regulates the in utero environment and functionally impacts fetal development. Candidate gene studies identified variation in placental DNA methylation is associated with newborn neurologic and behavioral outcomes including movement quality, lethargic behavior, attention, and arousal. We sought to identify novel regions of variable DNA methylation associated with newborn attention, lethargy, quality of movement, and arousal by performing an epigenome-wide association study in 335 infants from a US birth cohort. Methylation status was quantified using the Illumina HumanMethylation450 BeadChip array and associations to newborn outcomes assessed by the NICU Network Neurobehavioral Scales (NNNS) were identified while incorporating established bioinformatics algorithms to control for confounding by cell type composition. Methylation of CpGs within FHIT (cg15970800) and ANKRD11 (cg16710656) demonstrated genome-wide significance (P < 1.8 × 10−7) in specific associations with infant attention. CpGs whose differential methylation was associated with all 4 neurobehavioral outcomes were common to 50 genes involved in biological processes relating to cellular adhesion and nervous system development. Comprehensive methylation profiling identified relationships between methylation of FHIT and ANKRD11, which have been previously linked to neurodevelopment and behavioral outcomes in genetic association studies. Subtle changes in DNA methylation of these genes within the placenta may impact normal variation of a newborn's ability to alter and track visual and auditory stimuli. Gene ontology analysis suggested that those genes with variable methylation related to these outcomes are over-represented in biological pathways involved in brain development and placental physiology, supportive of our hypothesis for a key role of the placenta in neurobehavioral outcomes.

Prenatal DHA supplementation and infant attention.

Results of randomized trials on the effects of prenatal docosahexaenoic acid (DHA) on infant cognition are mixed, but most trials have used global standardized outcomes, which may not be sensitive to effects of DHA on specific cognitive domains. Women were randomized to 600 mg/d DHA or a placebo for the last two trimesters of pregnancy. Infants of these mothers were then followed on tests of visual habituation at 4, 6, and 9 mo of age. DHA supplementation did not affect look duration or habituation parameters but infants of supplemented mothers maintained high levels of sustained attention (SA) across the first year; SA declined for the placebo group. The supplemented group also showed significantly reduced attrition on habituation tasks, especially at 6 and 9 mo. The findings support with the suggestion that prenatal DHA may positively affect infants' attention and regulation of state.

Research Trends and Issues for Improving Joint Attention in Infants and Toddlers At Risk and with Autism Spectrum Disorders

연구목적: 본 연구는 국내 자폐 범주성 장애 영아의 공동관심 관련 중재 활성화를 위해 국외 자폐 범주성 장애 영아 및 장애위험 영아 대한 공동관심 중재 연구를 분석하여 동향을 알아보고 연구방법의 질적수준을 평가하였다. 연구방법: 2005년부터 2014년까지 최근 10년간 국외 공동관심 관련 연구가 분석대상이 되었으며 총 19편이 선정되었다. 선정된 논문의 연구동향은 발표연도, 연구대상, 실험설계, 독립변인, 종속변인, 실험결과에 따라 분석되었고, 질적수준은 특수교육 분야의 증거기반 실제를 위한 CEC(Council for Exceptional Children: CEC, 2014) 질적지표에 따라 분석되었다. 연구결과: 자폐 범주성 장애영아의 공동관심 증진을 위해 중재 제공자로 부모가 가장 많았으며, 중재 전략으로는 부모훈련, 자연적 행동훈련, 반응적 상호작용, 환경지원 등이 효과가 있었다. 결론: 연구결과 공동기술 향상에 효과적이며 유지 및 일반화에도 긍정적인 결과를 보여주더라도 연구에 참여한 모든 자폐 범주성 장애 혹은 장애위험 영아에게 효과가 있었던 것은 아니었다. 또한 질적지표를 적용한 결과, 이를 모두 만족시킨 논문은 19편의 논문 중 한편도 없었다. 논문 분석한 결과를 토대로 앞으로의 연구 활성화를 위한 방향 및 과제를 논의하였다.

Making Sense of Infant Familiarity and Novelty Responses to Words at Lexical Onset.

This study suggests that familiarity and novelty preferences in infant experimental tasks can in some instances be interpreted together as a single indicator of language advance. We provide evidence to support this idea based on our use of the auditory headturn preference paradigm to record responses to words likely to be either familiar or unfamiliar to infants. Fifty-nine 10-month-old infants were tested. The task elicited mixed preferences: familiarity (longer average looks to the words likely to be familiar to the infants), novelty (longer average looks to the words likely to be unfamiliar) and no-preference (similar-length of looks to both type of words). The infants who exhibited either a familiarity or a novelty response were more advanced on independent indices of phonetic advance than the infants who showed no preference. In addition, infants exhibiting novelty responses were more lexically advanced than either the infants who exhibited familiarity or those who showed no-preference. The results provide partial support for Hunter and Ames’ (1988) developmental model of attention in infancy and suggest caution when interpreting studies indexed to chronological age.

Effects of interstimulus intervals on behavioral, heart rate, and event-related potential indices of infant engagement and sustained attention.

Maximizing infant attention to stimulus presentation during an EEG or ERP experiment is important for making valid inferences about the neural correlates of infant cognition. The present study examined the effects of stimulus presentation interstimulus interval (ISI) on behavioral and physiological indices of infant attention including infants' fixation to visual presentation, the amount of heart rate (HR) change during sustained attention, and ERP components. This study compared an ISI that is typically used in infant EEG/ERP studies (e.g., 1,500-2,000 ms) with two shorter durations (400-600 ms and 600-1,000 ms). Thirty-six infants were tested cross-sectionally at 3, 4.5, and 6 months. It was found that using the short (400-600 ms) and medium (600-1,000 ms) ISIs resulted in more visually fixated trials and reduced frequency of fixation disengagement per experimental block. We also found larger HR changes during sustained attention to both of the shorter ISIs compared with the long ISI, and larger ERP responses when using the medium ISI compared to using the short and long ISIs. These data suggest that utilizing an optimal ISI (e.g., 600-1,000 ms), which increases the presentation complexity and provides sufficient time for information processing, can promote infant engagement and sustained attention during stimulus presentation.

The Social Origins of Sustained Attention in One-Year-Old Human Infants

The ability to sustain attention is a major achievement in human development and is generallybelieved to be the developmental product of increasing self-regulatory and endogenous (i.e., internal, top-down, voluntary) control over one's attention and cognitive systems [1-5]. Because sustained attention in late infancy is predictive of future development, and because early deficits in sustained attention are markers for later diagnoses of attentional disorders [6], sustained attention is often viewed as a constitutional and individual property of the infant [6-9]. However, humans are social animals; developmental pathways for seemingly non-social competencies evolved within the social group and therefore may be dependent on social experience [10-13]. Here, we show that social context matters for the duration of sustained attention episodes in one-year-old infants during toy play. Using head-mounted eye tracking to record moment-by-moment gaze data from both parents and infants, we found that when the social partner (parent) visually attended to the object to which infant attention was directed, infants, after the parent's look, extended their duration of visual attention to the object. Looks to the same object by two social partners is a well-studied phenomenon known as joint attention, which has been shown to be critical to early learning and tothe development of social skills [14, 15]. The present findings implicate joint attention in the development of the child's own sustained attention and thus challenge the current understanding of the origins ofindividual differences in sustained attention, providing a new and potentially malleable developmental pathway to the self-regulation of attention.

The Development of Attention Systems and Working Memory in Infancy.

In this article, we review research and theory on the development of attention and working memory in infancy using a developmental cognitive neuroscience framework. We begin with a review of studies examining the influence of attention on neural and behavioral correlates of an earlier developing and closely related form of memory (i.e., recognition memory). Findings from studies measuring attention utilizing looking measures, heart rate, and event-related potentials (ERPs) indicate significant developmental change in sustained and selective attention across the infancy period. For example, infants show gains in the magnitude of the attention related response and spend a greater proportion of time engaged in attention with increasing age (Richards and Turner, 2001). Throughout infancy, attention has a significant impact on infant performance on a variety of tasks tapping into recognition memory; however, this approach to examining the influence of infant attention on memory performance has yet to be utilized in research on working memory. In the second half of the article, we review research on working memory in infancy focusing on studies that provide insight into the developmental timing of significant gains in working memory as well as research and theory related to neural systems potentially involved in working memory in early development. We also examine issues related to measuring and distinguishing between working memory and recognition memory in infancy. To conclude, we discuss relations between the development of attention systems and working memory.

The Dynamics of Infant Attention: Implications for Crossmodal Perception and Word-Mapping Research.

The present review is a novel synthesis of research on infants' attention in two related domains-crossmodal perception and word mapping. The authors hypothesize that infant attention is malleable and shifts in real time. They review dynamic models of infant attention and provide empirical evidence for parallel trends in attention shifts from the two domains that support their hypothesis. When infants are exposed to competing auditory-visual stimuli in experiments, multiple factors cause attention to shift during infant-environment interactions. Additionally, attention shifts across nested timescales and individual variations in attention systematically explain development. They suggest future research to further elucidate the causal mechanisms that influence infants' attention dynamics, emphasizing the need to examine individual variations that index shifts over time.

Epigenetic Regulation of Placental NR3C1: Mechanism Underlying Prenatal Programming of Infant Neurobehavior by Maternal Smoking?

Epigenetic regulation of the placental glucocorticoid receptor gene (NR3C1) was investigated as a mechanism underlying links between maternal smoking during pregnancy (MSDP) and infant neurobehavior in 45 mother-infant pairs (49% MSDP-exposed; 52% minorities; ages 18-35). The Neonatal Intensive Care Unit (NICU) Network Neurobehavioral Scale was administered 7 times over the 1st postnatal month; methylation of placental NR3C1 was assessed via bisulfite pyrosequencing. Increased placental NR3C1 methylation was associated with increased infant attention and self-regulation, and decreased lethargy and need for examiner soothing over the 1st postnatal month. A causal steps approach revealed that NR3C1 methylation and MSDP were independently associated with lethargic behavior. Although preliminary, results highlight the importance of epigenetic mechanisms in elucidating pathways to neurobehavioral alterations from MSDP.

Genetic associations with reflexive visual attention in infancy and childhood

This study elucidates genetic influences on reflexive (as opposed to sustained) attention in children (aged 9-16years; N=332) who previously participated as infants in visual attention studies using orienting to a moving bar (Dannemiller, 2004). We investigated genetic associations with reflexive attention measures in infancy and childhood in the same group of children. The genetic markers (single nucleotide polymorphisms and variable number tandem repeats on the genes APOE, BDNF, CHRNA4, COMT, DRD4, HTR4, IGF2, MAOA, SLC5A7, SLC6A3, and SNAP25) are related to brain development and/or to the availability of neurotransmitters such as acetylcholine, dopamine, or serotonin. This study shows that typically developing children have differences in reflexive attention associated with their genes, as we found in adults (Lundwall, Guo & Dannemiller, 2012). This effort to extend our previous findings to outcomes in infancy and childhood was necessary because genetic influence may differ over the course of development. Although two of the genes that were tested in our adult study (Lundwall etal., 2012) were significant in either our infant study (SLC6A3) or child study (DRD4), the specific markers tested differed. Performance on the infant task was associated with SLC6A3. In addition, several genetic associations with an analogous child task occurred with markers on CHRNA4, COMT, and DRD4. Interestingly, the child version of the task involved an interaction such that which genotype group performed poorer on the child task depended on whether we were examining the higher or lower infant scoring group. These findings are discussed in terms of genetic influences on reflexive attention in infancy and childhood.

Infant and adult pupil dilation in response to unexpected sounds.

Surprisingly occurring sounds outside the focus of attention can involuntarily capture attention. This study focuses on the impact of deviant sounds on the pupil size as a marker of auditory involuntary attention in infants. We presented an oddball paradigm including four types of deviant sounds within a sequence of repeated standard sounds to 14-month-old infants and to adults. Environmental and noise deviant sounds elicited a strong pupil dilation response (PDR) in both age groups. In contrast, moderate frequency deviants elicited a significant PDR in adults only. Moreover, a principal component analysis revealed two components underlying the PDR. Component scores differ, depending on deviant types, between age groups. Results indicate age effects of parasympathetic inhibition and sympathetic activation of the pupil size caused by deviant sounds with a high arousing potential. Results demonstrate that the PDR is a sensitive tool for the investigation of involuntary attention to sounds in preverbal children.

Maternal Vocal Interactions with Infants: Reciprocal Visual Influences

AbstractThe present study examined the influence of infant visual cues on maternal vocal and facial expressiveness while speaking or singing and the influence of maternal visual cues on infant attention. Experiment 1 asked whether mothers exhibit more vocal emotion when speaking and singing to infants in or out of view. Adults judged which of each pair of audio excerpts (in view, out of view) sounded more emotional. Face‐to‐face vocalizations were judged more emotional than vocalizations to infants out of view. Moreover, mothers smiled considerably more while singing than while speaking to infants. Experiment 2 examined the influence of video feedback from infants on maternal speech and singing. Maternal vocalizations in the context of video feedback were judged to be less emotional than those in face‐to‐face contexts but more emotional than those in out‐of‐view contexts. Experiment 3 compared six‐month‐old infants’ attention to maternal speech and singing with audio‐only versions or with silent video‐only versions. Infants exhibited comparable attention to audio‐only versions of speech and singing but greater attention to video‐only versions of singing. The present investigation is unique in documenting the contribution of infant visual feedback to maternal vocal emotion in contexts that control for infants’ presence, visibility, and proximity.

The Role of Speech-Gesture Synchrony in Clipping Words From the Speech Stream: Evidence From Infant Pupil Responses

How do young infants discover that a segment of the sound stream refers to a particular aspect of the visual world around them? Speakers do not enunciate each word separately, even to infants; rather, whattheysayrunstogether. To relate an object (say, an apple) to its referent, infants must notice the interactant's target of attention (the apple) and at the same time single out the word that refers to it as the other person speaks (Lookattheapple!). We contend that caregivers through their actions assist by directing and educating an infant's attention, particularly through the use of a show gesture. The onset/offset, rhythm, tempo, and duration of these show gestures are synchronous with the saying of the words referring to the target objects. Our prior research using eye tracking found that show gestures lead an infant to look at the object presented as the word for it is uttered and that show gestures facilitate word learning. In this research we tested the hypothesis that show gestures also lead to enhanced attentional processing as measured through pupil dilation. Comparing pupil diameters while words were introduced with a show, static, or asynchronous dynamic gesture, we found that pupil dilation occurred for the show gesture condition and was positively correlated with word learning.

(Baby)Talk to Me

Since the mid-20th century, scientists have observed unique features in speech, facial expression, and content directed to infants and toddlers in comparison to speech directed to adults. Whereas much research has studied the characteristics of so-called infant-directed speech and speculated about its significance for language learning, research directly testing these ideas has been more limited until recently. Studies now suggest that infant-directed speech (a) promotes infant attention to language, (b) fosters social interaction between infants and caregivers, and (c) informs infants about various aspects of their native language by heightening distinctions relative to the speech addressed to adults. New developments focusing on the social role of infant-directed conversational interactions highlight the importance of caregiver responsiveness to the infant. Building a communicative foundation even prior to the time language emerges is crucial for fostering language development.

Patient needs and research priorities in probiotics: A quantitative KOL prioritization analysis with emphasis on infants and children

Due to broad application of probiotics, research efforts are diluted, thus contributing to rejection of health claims. This study aimed to systematically prioritize the unmet needs and research opportunities in infants, children, adults and elderly for probiotics according to their relative importance from a key-opinion-leader (KOL) perspective. In addition, it reveals potential probiotic product characteristics that need improvement from both a patient or consumer and a KOL perspective. Moreover, KOL involvement in the probiotic research & development (R&D) process was assessed. Data was collected by conducting semi-structured interviews and subsequent online questionnaires. The three clinical indications requiring the highest research attention for infants were (infectious) diarrhoea, antibiotic-associated diarrhoea (AAD) and necrotizing enterocolitis (NEC); for children, obesity, AAD and diarrhoea and for adults, AAD, irritable bowel syndrome (IBS) and Alzheimer’s disease. From both a KOL as well as a patient or consumer perspective, clinical evidence needs to be improved for probiotic products. Although the majority of the KOLs consult for and perform research with probiotic companies, they are (surprisingly) not able to sufficiently influence industry research agendas. This study incorporates the insights of KOLs and provides direction in the R&D of probiotics to fulfil unmet medical needs in patients.

Face Orientation and Motion Differently Affect the Deployment of Visual Attention in Newborns and 4-Month-Old Infants.

Orienting visual attention allows us to properly select relevant visual information from a noisy environment. Despite extensive investigation of the orienting of visual attention in infancy, it is unknown whether and how stimulus characteristics modulate the deployment of attention from birth to 4 months of age, a period in which the efficiency in orienting of attention improves dramatically. The aim of the present study was to compare 4-month-old infants’ and newborns’ ability to orient attention from central to peripheral stimuli that have the same or different attributes. In Experiment 1, all the stimuli were dynamic and the only attribute of the central and peripheral stimuli to be manipulated was face orientation. In Experiment 2, both face orientation and motion of the central and peripheral stimuli were contrasted. The number of valid trials and saccadic latency were measured at both ages. Our results demonstrated that the deployment of attention is mainly influenced by motion at birth, while it is also influenced by face orientation at 4-month of age. These findings provide insight into the development of the orienting visual attention in the first few months of life and suggest that maturation may be not the only factor that determines the developmental change in orienting visual attention from birth to 4 months.

Genetic variation in CD38 and breastfeeding experience interact to impact infants’ attention to social eye cues

Attending to emotional information conveyed by the eyes is an important social skill in humans. The current study examined this skill in early development by measuring attention to eyes while viewing emotional faces in 7-mo-old infants. In particular, we investigated individual differences in infant attention to eyes in the context of genetic variation (CD38 rs3796863 polymorphism) and experiential variation (exclusive breastfeeding duration) related to the oxytocin system. Our results revealed that, whereas infants at this age show a robust fear bias (increased attention to fearful eyes), their attention to angry and happy eyes varies as a function of exclusive breastfeeding experience and genetic variation in CD38. Specifically, extended exclusive breastfeeding duration selectively enhanced looking preference to happy eyes and decreased looking to angry eyes. Importantly, however, this interaction was impacted by CD38 variation, such that only the looking preferences of infants homozygous for the C allele of rs3796863 were affected by breastfeeding experience. This genotype has been associated with reduced release of oxytocin and higher rates of autism. In contrast, infants with the CA/AA genotype showed similar looking preferences regardless of breastfeeding exposure. Thus, differences in the sensitivity to emotional eyes may be linked to an interaction between the endogenous (CD38) and exogenous (breastfeeding) availability of oxytocin. These findings underline the importance of maternal care and the oxytocin system in contributing to the early development of responding to social eye cues.

Sustained attention in infancy as a longitudinal predictor of self-regulatory functions

Previous literature suggests that attention processes such as sustained attention would constitute a developmental foundation for the self-regulatory functions executive functioning and effortful control (e.g., Garon, Bryson, & Smith, 2008; Rothbart, Derryberry, & Posner, 1994). Our main aim was to test this hypothesis by studying whether sustained attention at age 1 year can predict individual differences in self-regulatory functions at age 2 years. Longitudinal data from 66 infants and their parents were included in the study. Sustained attention was assessed during free play at age 1 year; executive functioning, measured using an eye-tracking version of the A-not-B task, and effortful control, measured using parental ratings, were assessed at both age 1 and age 2 years. The results did support a longitudinal prediction of individual differences in 2-year-olds’ self-regulatory functions as a function of sustained attention at age 1 year. We also found significant improvement in both executive functioning and effortful control over time, and the two self-regulatory constructs were related in toddlerhood but not in infancy. The study helps increase our understanding of the early development of self-regulatory functions necessary for identifying developmental risks and, in the future, for developing new interventions.

The Infant Orienting With Attention task: Assessing the neural basis of spatial attention in infancy.

Infant visual attention develops rapidly over the first year of life, significantly altering the way infants respond to peripheral visual events. Here we present data from 5-, 7- and 10-month-old infants using the Infant Orienting With Attention (IOWA) task, designed to capture developmental changes in visual spatial attention and saccade planning. Results indicate rapid development of spatial attention and visual response competition between 5 and 10 months. We use a dynamic neural field (DNF) model to link behavioral findings to neural population activity, providing a possible mechanistic explanation for observed developmental changes. Together, the behavioral and model simulation results provide new insights into the specific mechanisms that underlie spatial cueing effects, visual competition, and visual interference in infancy.

Dyadic co-regulation, affective intensity and infant's development at 12 months: A comparison among extremely preterm and full-term dyads

Extremely low gestational age children (ELGA, born below 28 weeks of GA) represent the most at-risk preterm group in terms of survival, developmental sequelae and rates of impairment and cognitive delays. However, the impact of an extremely preterm birth on mother–infant co-regulation and affective intensity which may affect early infant's development has not been investigated. Based on a relational dynamic system approach, our study aimed to investigate the quality of co-regulation and affective intensity during spontaneous play interaction in 20 mother–infant ELGA dyads compared to 20 full-term (FT) dyads at 12 months (corrected age for ELGA infants). Relationships between the quality of dyadic co-regulation and the infant's level of cognitive, motor and language development were also investigated. The quality of dyadic co-regulation was assessed using the Revised Relational Coding System (R-RCS) by Fogel et al. (2003), the mothers’ and infants’ affective intensity was coded using a coding system by Lunkenheimer, Olson, Hollenstein, Sameroff, and Winter (2011). Infants’ development was assessed using the Bayley Scales (BSID-III, 2006). With respect to FT dyads, ELGA dyads were characterised by less frequent symmetric and more frequent unilateral co-regulation patterns and by less positive and more neutral affective intensity of both infants and mothers. Cognitive, motor and language scores were lower in ELGA infants than in FT infants. Symmetrical co-regulation was related to motor scores in ELGA infants, and to cognitive scores in FT infants. Our findings contribute to the literature by demonstrating the difficulties of ELGA mother–infant dyads at 12 months in sharing the symmetric co-regulation and positive affective intensity and how symmetric co-regulation is strictly related to motor development in ELGA infants. Based on these findings, intervention programmes to foster joint attention, active involvement and positive affective intensity in ELGA dyads and infants’ development in the first year of life should be designed.