Attention capacities of preterm and term born toddlers: A multi-method approach

A Longitudinal Study of Preterm Infants at 12 and 30 Months: Links Among Object Interactions, Joint Engagement, and Cognitive Development

Development takes place when change in one domain cascades into change in another domain. Preterm infants exhibit disruptions to their object play and the maintenance of a joint focus of attention with another person. Likewise, they tend to experience cognitive delays throughout childhood. By the developmental cascades model, early features of object play and joint engagement in preterm infants predict cognitive development. We examined longitudinal associations between real-time individual differences in parent-infant interactions and long-term outcomes to explore potential developmental processes. Features of infant-object interactions and joint engagement were coded in 20 12-month-old preterm infants (≤ 29 weeks of gestation) during parent-infant free play. Infants were tested again at 30 months using the Bayley Scales of Infant and Toddler Development, Third Edition. Preterm infants spent most of their time interacting with objects at 12 months, and their parents frequently engaged in their object interactions. The frequency of infant-object interaction bouts per minute at 12 months was negatively associated with 30-month cognitive scores. Furthermore, the percentage of infant-object interaction bouts in which parents practised multimodal engagement was marginally associated with 30-month cognitive scores. We discuss the associations of infant-object interactions and joint engagement with preterm infants' cognitive development.

The modulating effect of gestational age on attentional disengagement in toddlers

Gestational Age (GA) at birth plays a crucial role in identifying potential vulnerabilities to long-term difficulties in cognitive and behavioral development. The present study aims to explore the influence of gestational age on the efficiency of early visual attention orienting, as a potential marker for the development of specific high-level socio-cognitive skills. We administered the Gap-Overlap task to measure the attentional orienting and disengagement performance of 16-month-olds born between the 34th and 41st weeks of gestation. Our findings indicate that GA might be a significant predictor of attentional disengagement performance, with lower GAs associated with slower orienting of visual attention in the gap condition. Additionally, we discuss a possible influence of endogenous attention control on disengagement accuracy at this age, particularly among full-term infants. Overall, the findings highlight the role of GA as a key factor in evaluating early visual attention development, acting as a marker for detecting early vulnerabilities.

Orienting and Alerting Attention in Very Low and Normal Birth Weight Children at 42 Months: A Follow-up Study

OBJECTIVE

In preterm and very low birth weight (VLBW) infants, attention-related problems have been found to be more pronounced and emerge later as academic difficulties that may persist into school age. In response, based on three attention networks: alerting, orienting, and executive attention, we examined the development of attention functions at 42 months (not corrected for prematurity) as a follow-up study of VLBW (n = 23) and normal birth weight (NBW: n = 48) infants.

METHOD

The alerting and orienting attention networks were examined through an overlap task with or without warning signal. The orienting network was also examined through the distribution of gaze points when exposed to videos of human faces talking and silently looking straight ahead. Executive attention was examined using a parental report measure for temperamental self-regulation, effortful control.

RESULTS

In the overlap task, the difference between VLBWs and NBWs was not the latency of attentional disengagement but the fact that VLBWs were less focused on the fixation stimulus (F(1,60) = 10.80, p < .01, ηp2 = .071) and seemed to profit more from auditory warning signals than NBWs (F(1,60) = 7.13, p = .01, ηp2 = .106). Moreover, there was no intergroup difference regarding lateral (right or left) or feature (eye or mouth) attention bias toward the face videos. Further, longer latencies in overlap condition were significantly positively associated with high effortful control scores only in the NBW group (r = .36, p = .018).

CONCLUSION

Results indicate that poor underlying alertness and orienting relating to atypical lateralization may affect cognitive and behavioral abnormalities in VLBWs.

Voluntary Attention Assessing Tests in Children with Neurodevelopmental Disorders Using Eye Tracking

Background/Objectives: The development of techniques for assessing cognitive functions using eye tracking is particularly important for children with developmental disabilities. In this paper, we present pilot results from the validation of two methods for assessing voluntary attention based on eye tracking. Methods: The study involved 80 children aged 3 to 8 years with neurodevelopmental disorders. Children performed two eye-tracking tests in which they had to 'catch' a stimulus by looking at it. They also completed the Attention Sustained subtest of the Leiter-3 International Performance Scale. In the first test, the stimuli were presented at different locations on the screen in subtests with stimuli onset asynchrony of 2 s and 1 s. A translucent blue marker marked the position of the gaze on the screen. The number of trials in which the gaze marker approached the stimulus was determined. In the second test, the location of the stimuli on the screen was changed based on gaze fixation in the ROI area. The time taken to complete the task was evaluated. Results: The results of both eye-tracking tests showed significant correlations with scores on the Attention Sustained Leiter-3 subtest and significant test-retest reliability. Conclusions: The results indicate that the present eye-tracking tests can be used for assessing voluntary attention in children with some neurodevelopmental disorders, and further research is warranted to assess the feasibility of these tests for a broader range of developmental disorders. Our findings could have practical implications for the early intervention and ongoing monitoring of attention-related issues.

Attention control in preterm and term 5-month-old infants: Cross-task stability increases with gestational age

Cross-task stability refers to performance consistency across different settings and measures of the same construct. Cross-task stability can help us understand developmental processes, including how risks such as preterm birth affect outcomes. We investigated cross-task stability of attention control in 32 preterm and 39 term infants. All infants had the same chronological age at time of testing (5 months) but varied in gestational age (GA) at birth (30-42 weeks). Infants completed an experimental attention following task with a researcher and a naturalistic play observation with their mothers. Both preterm and term infants demonstrated attention following in the experimental task. GA and flexibility of attention were related: the likelihood of no turn trials decreased with increasing GA. To evaluate cross-task stability, we compared attention performance in the experimental and naturalistic settings. Flexible attention shifts on the experimental task were positively related to attention to objects in the naturalistic observation. Furthermore, the association between flexible attention shifts on the experimental task and attention to objects in the naturalistic observation was moderated by GA. Our study provides initial evidence that the consolidation of attention control increases with GA. These findings highlight the value of comparing experimental and observational measures of attention.

Preterm Birth and the Development of Visual Attention During the First 2 Years of Life: A Systematic Review and Meta-analysis

Importance

Preterm birth is associated with an increased risk for long-lasting attention deficits. Early-life markers of attention abnormalities have not been established to date but could provide insights into the pathogenesis of attention abnormalities and could help identify susceptible individuals.

Objective

To examine whether preterm birth is associated with visual attention impairments in early life, and if so, in which attention functions and at which developmental period during the first 2 years of life.

Data Sources

PubMed and PsycINFO were searched on November 17, 2019, to identify studies involving visual attention outcomes in infants born preterm vs full term.

Study Selection

Peer-reviewed studies from the past 50 years met the eligibility criteria if they directly assessed visual attention outcomes until the age of 2 years in generally healthy infants born preterm or full term. The selection process was conducted by 2 independent reviewers.

Data Extraction and Synthesis

The Meta-analysis of Observational Studies in Epidemiology (MOOSE) reporting guideline was followed. Random-effects models were used to determine standardized mean differences. The risk of bias was assessed both within and between studies.

Main Outcomes and Measures

Five nascent indices of visual attention were analyzed, including very basic functions-namely, the abilities to follow and fixate on visual targets-and more complex functions, such as visual processing (ie, habituation), recognition memory (ie, novelty preference), and the ability to effortfully focus attention for learning.

Results

A total of 53 studies were included, with 69 effect sizes and assessing a total of 3998 infants (2047 born preterm and 1951 born full term; of the 3376 for whom sex was reported, 1693 [50.1%] were girls). Preterm birth was associated with impairments in various attention indices, including visual-following in infancy (Cohen d, -0.77; 95% CI, -1.23 to -0.31), latency to fixate (Cohen d, -0.18; 95% CI, -0.33 to -0.02), novelty preference (Cohen d, -0.20; 95% CI, -0.32 to -0.08), and focused attention (Cohen d, -0.28; 95% CI, -0.45 to -0.11). In the neonatal period, preterm birth was associated with superior visual-following (Cohen d, 0.22; 95% CI, 0.03 to 0.40), possibly owing to the additional extrauterine exposure to sensory stimulation. However, this early association waned rapidly in infancy (Cohen d, -0.77; 95% CI, -1.23 to -0.31).

Conclusions and Relevance

The findings suggest that preterm birth is associated with impingements to visual attention development in early life, as manifested in basic and then complex forms of attention. Advancements in neonatal care may underlie improvements found in the current era and accentuate several early protective factors.

Distinct Profiles of Attention in Children Born Moderate-to-Late Preterm at 6 Years

Objective

Attention difficulties are commonly reported by caregivers in school-aged children born moderate-to-late preterm (MLPT; 32–36 weeks’ gestation). We aimed to assess distinct aspects of attentional functioning (i.e. orienting, alerting and executive attention, processing speed and behavioral components) in children born MLPT and full term (FT), profiles of attentional functioning, and associated risk factors such as preterm birth.

Methods

Participants were 170 (87 MLPT and 83 FT) children, evaluated on cognitive and behavioral attention aspects at 6 years of age. We used a variable-centered approach to compare attentional functioning of children born MLPT and FT at group level, and a person-centered approach to identify profiles of attentional functioning. Neonatal and demographic characteristics of these profiles were compared.

Results

The variable-centered approach showed that at group level children born MLPT had poorer orienting attention and processing speed, and behavioral attention than children born FT. The person-centered approach revealed four profiles: (a) normal attentional functioning, (b) overall poorer attention, (c) poorer cognitive attention, and (d) behavioral attention problems. Children born MLPT were overrepresented in each of the suboptimal attention profiles, and were more dispersed across profiles than children born FT.

Conclusions

Children born MLPT are at increased risk of difficulties in some attention aspects, but at group level differences with children born FT are small. However, children born MLPT show considerable variation in the nature of attention difficulties and are twice as likely to show a suboptimal attention profile, indicating a cumulation of poorer attention scores.

Reliability and Validity of the Utrecht Tasks for Attention in Toddlers Using Eye Tracking (UTATE)

Attention problems hinder many children in their cognitive and social emotional development. Children at risk for developmental problems, like preterm born infants, are specifically known for attention difficulties. Early identification of attention difficulties is important for application of appropriate stimulation in trying to reduce further problems. Specifically designed instruments with good psychometric characteristics are needed to show difficulties in attention, that may contribute to early identification. The Utrecht Tasks of Attention in Toddlers using Eye tracking (UTATE) is an instrument to measure orienting, alerting and executive attention capacities in young children. Reliability and validity of the UTATE are specifically addressed in three studies, reported in this paper. A sample of 95 term born children assessed at 18 months of age was used that provided data for both the second and third study reported here. In addition, three other small samples were used, of which the first consisted of 12 children at 18 months with test-retest data available that are reported in the first study. Two other samples that were used in the third study, consisted of 14 children measured at 12 months, and 15 children examined at 24 months. The UTATE resulted in reliable information on eye movements and some first support for construct and predictive validity was found. Low scores on the UTATE at 18 months were found to be related to slower cognitive development as measured with the Bayley-III-NL at 24 months. Furthermore, a first indication that the UTATE is able to detect some age differences in attention was found. It is concluded that the UTATE can be used to study attention capacities in toddlers that underlie cognitive functioning and development, but further research is necessary.

Joint attention abilities in Brazilian preterm and full-term infants

Joint attention abilities of preterm and full-term Brazilian infants were assessed at 12- and 18-months, age corrected for prematurity. Results showed that preterm infants displayed significantly lower levels of correct responses to others' bids for joint attention at both time-points, compared to full-term infants. Both groups improved their responding to joint attention from 12 to 18 months of age. Contrastingly, prematurity did not impact infants' initiating joint attention behaviors, which remained stable over time for both groups. Findings were discussed in terms of the specific mental processes involved in distinct behavioural dimensions of joint attention.

Toddler skills predict moderate-to-late preterm born children's cognition and behaviour at 6 years of age

OBJECTIVE

To compare moderate-to-late preterm born (32-36 weeks' gestation) to full term born (≥37 weeks' gestation) children in cognitive and behavioural functioning at the age of 6 years and assess which toddler skills predict later cognitive and behavioural functioning.

DESIGN

A prospective longitudinal study with a cohort of 88 moderate-to-late preterm and 83 full term born Dutch children, followed from 18 months to 6 years of age. Orienting, alerting and executive attention skills were assessed at 18 months (corrected for prematurity), and cognitive, motor and language skills (Bayley-III-NL) at 24 months (corrected for prematurity). At 6 years (corrected for prematurity), cognitive (indices of IQ; WPPSI-III-NL) and behavioural functioning (CBCL/6-18) were assessed. Group differences and potential predictors were examined with MANCOVAs and hierarchical regression analyses.

RESULTS

At 6 years, moderate-to-late preterm born children performed poorer than full term born children on cognitive processing speed, and they showed more behavioural attention problems. Attention problems at 6 years were predicted by poorer orienting attention skills at 18 months, while lower performance IQ was predicted by poorer alerting attention skills at 18 months. Full Scale IQ and Verbal IQ at 6 years were predicted by language skills at 24 months. Moderate-to-late preterm and full term born children showed some differing correlational patterns in the associations between early skills and later functioning, although in further analyses predictors appeared the same for both groups.

CONCLUSIONS

Moderate-to-late preterm born children show specific vulnerabilities at primary school-age, particularly in cognitive processing speed and behavioural attention problems. Cognitive and behavioural functioning at 6 years can be predicted by differentiated attention skills at 18 months and language skills at 24 months.

Perinatal risk factors for visuospatial attention and processing dysfunctions at 1 year of age in children born between 26 and 32 weeks

BACKGROUND

Children born preterm are at risk of visuospatial attention orienting and processing dysfunctions, which can be quantified early in life using visually-guided eye movement responses.

AIMS

To identify the prevalence and perinatal risk factors for visuospatial attention orienting and processing dysfunctions in children born preterm of 1 year of corrected age (CA).

STUDY DESIGN

123 children born between 26 and 33 weeks of gestation underwent a nonverbal visuospatial test at 1y CA, using an eye tracking-based paradigm. For the detected high-salient (cartoon and contrast), intermediate-salient (form and motion) and low-salient (color) stimuli, we quantified the reaction time to fixation (RTF). RTFs were compared to normative references from an age-matched control group (N = 38). The prevalence of perinatal risk factors (gestational age and weight, indices of neurological damage, overal sickness, respiratory failure, and retinopathy) was compared between the groups with normal and delayed RTFs.

RESULTS

At 1y CA, the preterm group had 7-20% less detected stimuli than the control group, particularly for intermediate and low-salient stimuli. Compared to normative RTFs, modest delays were found for high-salient cartoon (in 19% of preterm children) and contrast (8%), intermediate-salient motion (23%) and form (21%), and low-salient color stimuli (8%). These children had a significantly higher prevalence of perinatal risk factors for respiratory failure and intraventricular hemorrhages.

CONCLUSIONS

Children born between 26 and 32 weeks have a modest risk (8-23%) of visuospatial attention and processing dysfunction. This warrants early monitoring and support of general visual development in preterm children at risk of respiratory distress and disrupted cerebral blood flow.

Early development of visual attention in infants in rural Malawi

Eye tracking research has shown that infants develop a repertoire of attentional capacities during the first year. The majority of studies examining the early development of attention comes from Western, high-resource countries. We examined visual attention in a heterogeneous sample of infants in rural Malawi (N = 312-376, depending on analysis). Infants were assessed with eye-tracking-based tests that targeted visual orienting, anticipatory looking, and attention to faces at 7 and 9 months. Consistent with prior research, infants exhibited active visual search for salient visual targets, anticipatory saccades to predictable events, and a robust attentional bias for happy and fearful faces. Individual variations in these processes had low to moderate odd-even split-half and test-retest reliability. There were no consistent associations between attention measures and gestational age, nutritional status, or characteristics of the rearing environment (i.e., maternal cognition, psychosocial well-being, socioeconomic status, and care practices). The results replicate infants' early attentional biases in a large, unique sample, and suggest that some of these biases (e.g., bias for faces) are pronounced in low-resource settings. The results provided no evidence that the initial manifestation of infants' attentional capacities is associated with risk factors that are common in low-resource environments.

Rapid Infant Prefrontal Cortex Development and Sensitivity to Early Environmental Experience

Over the last fifteen years, the emerging field of developmental cognitive neuroscience has described the relatively late development of prefrontal cortex in children and the relation between gradual structural changes and children's protracted development of prefrontal-dependent skills. Widespread recognition by the broader scientific community of the extended development of prefrontal cortex has led to the overwhelming perception of prefrontal cortex as a "late developing" region of the brain. However, despite its supposedly protracted development, multiple lines of research have converged to suggest that prefrontal cortex development may be particularly susceptible to individual differences in children's early environments. Recent studies demonstrate that the impacts of early adverse environments on prefrontal cortex are present very early in development: within the first year of life. This review provides a comprehensive overview of new neuroimaging evidence demonstrating that prefrontal cortex should be characterized as a "rapidly developing" region of the brain, discusses the converging impacts of early adversity on prefrontal circuits, and presents potential mechanisms via which adverse environments shape both concurrent and long-term measures of prefrontal cortex development. Given that environmentally-induced disparities are present in prefrontal cortex development within the first year of life, translational work in intervention and/or prevention science should focus on intervening early in development to take advantages of this early period of rapid prefrontal development and heightened plasticity.

Neonatal intensive care unit phthalate exposure and preterm infant neurobehavioral performance

Every year in the United States, more than 300,000 infants are admitted to neonatal intensive care units (NICU) where they are exposed to a chemical-intensive hospital environment during a developmentally vulnerable period. The neurodevelopmental impact of environmental exposure to phthalates during the NICU stay is unknown. As phthalate exposure during the third trimester developmental window has been implicated in neurobehavioral deficits in term-born children that are strikingly similar to a phenotype of neurobehavioral morbidity common among children born premature, the role of early-life phthalate exposure on the neurodevelopmental trajectory of premature infants may be clinically important. In this study, premature newborns with birth weight <1500g were recruited to participate in a prospective environmental health cohort study, NICU-HEALTH (Hospital Exposures and Long-Term Health), part of the DINE (Developmental Impact of NICU Exposures) cohort of the ECHO (Environmental influences on Child Health Outcomes) program. Seventy-six percent of eligible infants enrolled in the study. Sixty-four of 81 infants survived and are included in this analysis. 164 urine specimens were analyzed for phthalate metabolites using high-performance liquid chromatography/tandem mass spectrometry. The NICU Network Neurobehavioral Scale (NNNS) was performed prior to NICU discharge. Linear and weighted quantile sum regression quantified associations between phthalate biomarkers and NNNS performance, and between phthalate biomarkers and intensity of medical intervention. The sum of di(2-ethylhexyl) phthalate metabolites (∑DEHP) was associated with improved performance on the Attention and Regulation scales. Specific mixtures of phthalate biomarkers were also associated with improved NNNS performance. More intense medical intervention was associated with higher ∑DEHP exposure. NICU-based exposure to phthalates mixtures was associated with improved attention and social response. This suggests that the impact of phthalate exposure on neurodevelopment may follow a non-linear trajectory, perhaps accelerating the development of certain neural networks. The long-term neurodevelopmental impact of NICU-based phthalate exposure needs to be evaluated.

Early executive function differences in infants born moderate-to-late preterm

Individuals who are born very preterm (<32weeks gestation) show differential development of prefrontal cortex structure, function, and dependent behaviors, including executive function (EF) skills, beginning during late infancy and extending into adulthood. Preschool-aged children born moderate-to-late preterm (PT; 32-36weeks gestation) show smaller discrepancies in EF development, but it is unclear whether these differences first emerge during the early childhood years, when EF is rapidly developing, or if they arise from alterations in complex cognitive skills measurable in late infancy. In the current study, we examined whether differences in complex attention, memory, and inhibition skills (precursor skills to EF) are altered in healthy infants born moderate-to-late PT at 9-months corrected age. Infants born PT demonstrated poorer memory at test following habituation than their full-term peers. Furthermore, lower gestational age at birth was associated with poorer performance on five of the six early EF tasks. Results indicate that even in the context of low medical and environmental risk, performance on the Bayley within the normal range, and no group-level differences in processing speed, infants born moderate-to-late PT show subtle alterations in cognitive skills presumed to be dependent on prefrontal cortex by 9-months of age, likely setting the stage for long-term differences in EF development.