Processing speed in the 1st year of life: a longitudinal study of preterm and full-term infants

Executive Functions Rehabilitation in Premature Children Using an Adaptive Motion-Interaction Videogame Platform: A Randomized Controlled Trial

Background: Premature children are at increased risk of executive functions (EF) deficits and these difficulties persist into adolescence and adulthood, potentially undermining their development and academic achievements. The aim of the present randomized controlled trial (RCT) is to evaluate the efficacy of the Intendu trainer, an adaptive virtual reality platform, at ameliorating EF in preterm children. Methods: A single-center, RCT was conducted. The intervention group was exposed to game session with the Intendu software in addition to the standard of care in use in our center. The main outcome was the proportion of children with a 10-point increase in the processing speed quotient as measured by WPPSI-III after 4 weeks from the baseline assessment. Results: Forty-seven children born before 36 + 5 weeks were randomized to the experimental (n = 24) or control arm (n = 23). Five children were lost to follow-up. Thirteen of 23 children (56%) reached the main outcome in the experimental group and 5 of 19 (26%) in the control group (P = 0.049, per-protocol analysis) with an absolute benefit increase (ABI) of 30% reconfirmed by the intention-to-treat analysis (P = 0.022, ABI of 32%). Conclusion: Intendu brain-trainer showed promising short-term results on EF in pre-term children, however, larger studies with longer periods of follow-up are warranted to better investigate the role of this or similar technology in promoting better EF in preterm children.

Leveraging technological advances to assess dyadic visual cognition during infancy in high- and low-resource settings

Caregiver-infant interactions shape infants' early visual experience; however, there is limited work from low-and middle-income countries (LMIC) in characterizing the visual cognitive dynamics of these interactions. Here, we present an innovative dyadic visual cognition pipeline using machine learning methods which captures, processes, and analyses the visual dynamics of caregiver-infant interactions across cultures. We undertake two studies to examine its application in both low (rural India) and high (urban UK) resource settings. Study 1 develops and validates the pipeline to process caregiver-infant interaction data captured using head-mounted cameras and eye-trackers. We use face detection and object recognition networks and validate these tools using 12 caregiver-infant dyads (4 dyads from a 6-month-old UK cohort, 4 dyads from a 6-month-old India cohort, and 4 dyads from a 9-month-old India cohort). Results show robust and accurate face and toy detection, as well as a high percent agreement between processed and manually coded dyadic interactions. Study 2 applied the pipeline to a larger data set (25 6-month-olds from the UK, 31 6-month-olds from India, and 37 9-month-olds from India) with the aim of comparing the visual dynamics of caregiver-infant interaction across the two cultural settings. Results show remarkable correspondence between key measures of visual exploration across cultures, including longer mean look durations during infant-led joint attention episodes. In addition, we found several differences across cultures. Most notably, infants in the UK had a higher proportion of infant-led joint attention episodes consistent with a child-centered view of parenting common in western middle-class families. In summary, the pipeline we report provides an objective assessment tool to quantify the visual dynamics of caregiver-infant interaction across high- and low-resource settings.

Delineating Visual Habituation Profiles in Preschoolers with Neurofibromatosis Type 1 and Autism Spectrum Disorder: A Cross-Syndrome Study

Atypical habituation to repetitive information has been commonly reported in Autism Spectrum Disorder (ASD) but it is not yet clear whether similar abnormalities are present in Neurofibromatosis Type 1 (NF1). We employed a cross-syndrome design using a novel eye tracking paradigm to measure habituation in preschoolers with NF1, children with idiopathic ASD and typically developing (TD) children. Eye movements were recorded to examine fixation duration to simultaneously presented repeating and novel stimuli. Children with NF1 showed a bias for longer look durations to repeating stimuli at the expense of novel stimuli, and slower habituation in NF1 was associated with elevated ASD traits. These findings could indicate aberrant modulation of bottom-up attentional networks that interact with the emergence of ASD phenotypes.

Associations among maternal lifetime trauma, psychological symptoms in pregnancy, and infant stress reactivity and regulation

Maternal trauma has intergenerational implications, including worse birth outcomes, altered brain morphology, and poorer mental health. Research investigating intergenerational effects of maternal trauma on infant stress reactivity and regulation is limited. Maternal mental health during pregnancy may be a contributor: psychopathology is a sequela of trauma exposure and predictor of altered self-regulatory capacity in offspring of affected mothers. We assessed associations among maternal lifetime trauma and infant stress responsivity, mediated by psychological symptoms in pregnancy. Mothers reported lifetime trauma history and anxiety, depressive, and posttraumatic stress symptoms during pregnancy. At infant age 6 months, stress reactivity and regulation were assessed via maternal behavior ratings (Infant Behavior Questionnaire-Revised, IBQ-R) and behavioral (negative mood) and physiological (respiratory sinus arrhythmia, RSA) markers during a laboratory stressor (Still-Face Paradigm). Maternal trauma was directly associated with lower infant physiological regulation and indirectly associated with lower levels of both infant behavioral and physiological regulation via higher maternal anxiety during pregnancy. Maternal trauma was also indirectly associated with higher infant reactivity via higher maternal anxiety during pregnancy. Post hoc analyses indicated differential contributions of maternal prenatal versus postnatal anxiety to infant outcomes. Findings highlight potential contributory mechanisms toward maladaptive child stress response, which has been associated with poor behavioral, cognitive, and academic outcomes.

A review of the characteristics, mechanisms and clinical significance of habituation in foetuses and newborn infants

Habituation has been a topic of interest since the early 20th century. We summarise the characteristics of habituation, the proposed habituation mechanisms, the associated cortical responses and the link between habituation and cognitive development. Behavioural and neuroimaging studies have highlighted the early sensory abilities of foetuses and newborn infants, with preterm newborn infants exhibiting decreased habituation and dishabituation capabilities that increase their environmental vulnerability. Habituation provides a foundation for the learning and cognition on which higher functions are constructed. It has been suggested that it is efficient for predicting cognitive developmental outcomes in term and preterm newborn infants.

Heterogeneity of the attentional system's efficiency among very prematurely born pre-schoolers

Very preterm birth increases the risk of ADHD as well as other neurodevelopmental disorders. Deficits within the attentional system were previously signaled in preterm children; however, studies lacked in consideration of an intragroup differentiation. Thus, this study aimed to verify whether deficits in the attentional mechanisms are inter-individually differentiated among very prematurely born children and if so, which biomedical and non-biomedical factors are associated with the profile of deficits within the attentional system. We tested the efficiency of attentional processes among 5-year-old children with the Attention Network Task - Child Version. The results have indicated that 26% of very preterm children presented with the suboptimal functioning of the attentional system (more than 1 SD below mean score of full-term children in attentional alerting and orienting), whereas 74% were characterized by the normal efficiency of attention. The profile of attentional deficits observed among very preterm preschoolers was associated with significantly lower birth weight and decreased family living standard. Very prematurely born children are thus a relatively heterogeneous group in terms of the efficiency of attentional system and deficits apply to only some of those children. Early developmental support aimed at enhancing attentional functioning should be addressed to children with lower birth weight in the first place.

Exploring predictors at toddler age of distinct profiles of attentional functioning in 6-year-old children born moderate-to-late preterm and full term

OBJECTIVE

Examining relationships of toddler abilities in attention, cognitive, motor, and language development, and behavioral problems, with distinct attention profiles at 6 years of age in children born moderate-to-late preterm and full term.

METHOD

Longitudinal study with a cohort of 88 moderate-to-late preterm and 83 full term born children. At 18 months attention abilities were assessed. At 24 months cognitive, motor, and language development was examined and behavioral problems were screened. At 6 years ten measures of attention were administered, which were used to classify children in one of four attentional functioning profiles (normal attention, overall poorer attention, poorer cognitive attention, and behavioral attention problems). Performance at 18 and 24 months was examined in relation to these four distinct attention profiles, as well as in relation to normal (first profile) versus subaverage attention (second, third, and fourth profiles) using multinomial logistic regressions.

RESULTS

Orienting and alerting attention, and receptive language were related to distinct attention profiles. Specifically, children with an overall poorer attention profile at 6 years were differentiated by lower orienting attention and receptive language scores at toddler age, while those with a poorer cognitive attention profile showed lower early alerting attention at 18 months. Children with a behavioral attention problems profile at 6 years were differentiated by lower orienting attention but higher alerting attention scores at toddler age. Orienting attention and receptive language, but not alerting attention, at toddler age were related to normal versus subaverage attention, with lower scores predicting subaverage attention.

CONCLUSIONS

Children at risk of poorer attentional functioning at school-age, expressed in distinct attention profiles, already showed differentiated functioning in attention abilities and in language comprehension as toddlers. Distinguishing distinct attention profiles could be important for future research and clinical practice, as is early monitoring of attention and language abilities in children at risk.

Social cognition in individuals born preterm

Faces hold a substantial value for effective social interactions and sharing. Covering faces with masks, due to COVID-19 regulations, may lead to difficulties in using social signals, in particular, in individuals with neurodevelopmental conditions. Daily-life social participation of individuals who were born preterm is of immense importance for their quality of life. Here we examined face tuning in individuals (aged 12.79 ± 1.89 years) who were born preterm and exhibited signs of periventricular leukomalacia (PVL), a dominant form of brain injury in preterm birth survivors. For assessing the face sensitivity in this population, we implemented a recently developed experimental tool, a set of Face-n-Food images bordering on the style of Giuseppe Arcimboldo. The key benefit of these images is that single components do not trigger face processing. Although a coarse face schema is thought to be hardwired in the brain, former preterms exhibit substantial shortages in the face tuning not only compared with typically developing controls but also with individuals with autistic spectrum disorders. The lack of correlations between the face sensitivity and other cognitive abilities indicates that these deficits are domain-specific. This underscores impact of preterm birth sequelae for social functioning at large. Comparison of the findings with data in individuals with other neurodevelopmental and neuropsychiatric conditions provides novel insights into the origins of deficient face processing.

Assessing processing speed among individuals with intellectual and developmental disabilities: A match-to-sample paradigm

Speeded Matching (SpM) is a new processing speed match-to-sample test within the NIH Toolbox Cognitive Battery. It was designed to developmentally extend feasibility to younger children or individuals with intellectual or developmental disabilities (IDD). SpM reduces cognitive demands to tapping an identical match as opposed to judging and indicating whether two stimuli are identical. In this study, we piloted SpM among 148 participants with fragile X syndrome, Down syndrome, or other intellectual disabilities (chronological age mean = 17.8 years, sd = 5.4; nonverbal mental age mean = 65 months, sd = 19.4). SpM had a high feasibility (96%) and internal consistency (r_xx = 0.98). It converged well with other measures of processing speed, fluid cognition, and nonverbal mental age and diverged appropriately from crystallized cognitive skills. The correlation between nonverbal mental age and SpM in the IDD sample was not significantly different than the correlation between chronological age and SpM in a separate sample of 118 neurotypical children (age mean = 3.9 years sd = 0.8). This study provides initial evidence for the reliability and validity of the new SpM task, which may be appropriate as an outcome measure of processing speed for future clinical trials. It is more feasible than tasks designed for adults; it is brief, easy to administer, and engaging for young children and older individuals with lower mental ages associated with IDD.

Very preterm infants engage in an intervention to train their control of attention: results from the feasibility study of the Attention Control Training (ACT) randomised trial

Background

Very premature birth (gestational age between 28 and 31 + 6 weeks) is associated with increased risk of cognitive delay and attention deficit disorder, which have been linked to anomalies in the development of executive functions (EFs) and their precursors. In particular, very preterm (VP) infants display anomalies in controlling attention and gathering task-relevant information. Early interventions that support attention control may be pivotal in providing a secure base for VP children’s later attainments. The Attention Control Training (ACT) is a cognitive training intervention that targets infants’ abilities to select visual information according to varying task demands but had not been tested in VP infants. We conducted a feasibility study to test the processes we intend to use in a trial delivering the ACT to VP infants.

Methods and design

We tested recruitment and retention of VP infants and their families in a randomised trial, as well as acceptability and completion of baseline and outcome measures. To evaluate these aims, we used descriptive quantitative statistics and qualitative methods to analyse feedback from infants’ caregivers. We also investigated the quality of eye-tracking data collected and indicators of infants’ engagement in the training, using descriptive statistics.

Results

Twelve VP infants were recruited, and 10 (83%) completed the study. Participants’ parents had high education attainment. The rate of completion of baseline and outcome measures was optimal. VP infants demonstrated engagement in the training, completing on average 84 min of training over three visits, and displaying improved performance during this training. Eye-tracking data quality was moderate, but this did not interfere with infants’ engagement in the training.

Discussion

The results suggest the ACT can be delivered to VP infants. However, challenges remain in recruitment of numerous and diverse samples. We discuss strategies to overcome these challenges informed by results of this study.

Trial registration

Registered Registration ID: NCT03896490. Retrospectively registered at Clinical Trials Protocol Registration and Results System (clinicaltrials.gov).

Supplementary Information

The online version contains supplementary material available at 10.1186/s40814-021-00809-z.

Do low birth weight infants not see eyes? Face recognition in infancy

BACKGROUND

Progress in neonatal medicine has dramatically improved the survival rate of preterm births, but the evidence suggests that these low-birth weight infants (LBWIs) go on to develop pervasive development disorders and attention deficit hyperactivity disorder (ADHD) at greater rates than the general population. Children with neurodevelopmental disorders are known to suffer from deficits in visual cognition, such as in face perception and attentional functions, the characteristics of which already manifest in early infancy.

PURPOSE

This study aimed to investigate visual cognition in LBWIs during infancy.

SUBJECTS

20 LBWIs and 20 normal-birth-weight infants (NBWIs: control) of age 9-10 months (corrected age was used for LBWIs).

METHOD

Children were held seated in front of an eye tracking system by a parent, and presented with facial photos as visual stimuli. During the familiarization phase, the child was presented with two images of the same human face (familiarization stimulus) on the left and right side of a display screen (5 × 10 s trials). Next, during the test phase, the child was presented with the same image on one side of the screen, and a photo of a different person's face (novel stimulus) on the other (2 × 5 s trials). Gaze behavior was assessed in terms of the total time spent looking at either facial stimulus, and specifically at the eyes of the stimuli, as well as the number of attentional shifts between stimuli, and novelty preference.

RESULTS/DISCUSSION

LBWIs spent significant less time looking at facial stimuli overall, and less time at the eye region, than NBWIs. These findings seem to evidence developmental differences in functions related to visual cognition.

Habituation Alteration in Infants with Periventricular Echogenicity as an Indicator of Neurocognitive Impairment

Habituation difficulties may suggest neurocognitive impairment. Periventricular echogenicity (PVE) potentially causes subtle damage that poses neuropsychological risk. Habituation was evaluated through heart rate and behavioral states in infants at 36-37 weeks of corrected age between control and PVE groups. PVE infants showed early alertness and abrupt changes in behavioral states. However, the comparison group could better regulate their states. Heart rate was significantly high and remained unchanged in the PVE group but decreased in the control group. Alterations during the habituation paradigm in PVE infants could be early indicators of neuropsychological risk impairment. Scope of early habituation assessment is discussed.

Parental Linguistic Input and Its Relation to Toddlers' Visual Attention in Joint Object Play: A Comparison Between Children with Normal Hearing and Children With Hearing Loss

Parent-child interactions are multimodal, often involving coordinated exchanges of visual and auditory information between the two partners. The current work focuses on the effect of children's hearing loss on parent-child interactions when parents and their toddlers jointly played with a set of toy objects. We compared the linguistic input received by toddlers with hearing loss (HL) and their chronological age-matched (CA) and hearing age-matched (HA) normal-hearing peers. Moreover, we used head-mounted eye trackers to examine how different parental linguistic input affected children's visual attention on objects when parents either led or followed children's attention during joint object play. Overall, parents of children with HL provided comparable amount of linguistic input as parents of the two normal-hearing groups. However, the types of linguistic input produced by parents of children with HL were similar to the CA group in some ways and similar to the HA group in other ways. Interestingly, the effects of different types of linguistic input on extending the attention of children with HL qualitatively resembled the patterns seen in the CA group, even though the effects were less pronounced in the HL group. We discuss the implications of these results for our understanding of the reciprocal, dynamic, and multi-factored nature of parent-child interactions.

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.

Characterization of performance on an automated visual recognition memory task in 7.5-month-old infants

Infant looking behaviors measured during visual assessment paradigms may be more reliable predictors of long-term cognitive outcomes than standard measures such as the Bayley Scales of Infant Development typically used in environmental epidemiology. Infrared eye tracking technology offers an innovative approach to automate collection and processing of looking behavior data, making it possible to efficiently assess large numbers of infants. The goals of this study were to characterize infant looking behavior measures including side preference, fixation duration, and novelty preference using eye tracking and an automated version of an established visual recognition memory paradigm that includes both human faces and geometric figures as stimuli. An ancillary goal was to assess the feasibility of obtaining a precise measure of looking to the eye region of faces from the eye-tracking data. In this study, 309 7.5-month-old infants from a prospective birth cohort were assessed using a visual recognition memory (VRM) paradigm. Infrared eye tracking was used to record looking time as infants were shown nine blocks of trials with a pair of identical faces or shapes followed by two trials in which the familiar stimulus was paired with a novel one. Infants were assessed in one of four conditions: in conditions A and B, stimulus set 1 were the familiar stimuli and set 2 were novel; in conditions C and D, set 2 were familiar and set 1 novel. The novel stimuli were presented on the right first in conditions A and C and on the left first in conditions B and D. We observed a significant right side preference, which has not been reported before (57% of looking time spent looking at right side stimulus, p-value < 0.0001). Infants showed a preference for the novel stimuli similar to that published in prior studies (57-60% of looking time spent looking at the novel stimulus, p-value < 0.0001), as well as average fixation durations similar to previous studies. Infants also showed a strong preference for the eyes versus the rest of the face (p-value < 0.0001). Novelty preference was significantly higher when set 2 stimuli were novel (p-value < 0.0001), suggesting a preference among infants for set 2 stimuli compared to set 1 stimuli. The pattern of novelty preference across trials was significantly different between infants who saw the novel stimuli on the left first and those who saw them on the right first (p-value < 0.0001) but the overall mean novelty preference was not significantly different between these groups. There were also significant differences in average fixation duration and eyes preference measures across stimuli (p-values < 0.05). These findings show that VRM assessment can be automated for use in large-scale epidemiological studies using infrared eye tracking with looking behavior measure results similar to those obtained with standard non-automated methods, and that side and stimulus preferences are important modifiers of looking behavior that are critical to consider in this type of assessment.

Efficacy of Supporting Play Exploration and Early Development Intervention in the First Months of Life for Infants Born Very Preterm: 3-Arm Randomized Clinical Trial Protocol

OBJECTIVE

The aim of this project is to study the effect of a physical therapist intervention provided in the first months of life on developmental outcomes of infants born very preterm. Secondary aims are to investigate the impact of intervention timing on the efficacy and impact of the intervention on infants with and without cerebral palsy.

METHODS

This study is a multisite longitudinal controlled trial comparing developmental outcomes from infants in the Supporting Play, Exploration, and Early Development Intervention (SPEEDI)_Late or SPEEDI_Early group to a usual care group.

SETTINGS ARE URBAN

Urban and rural areas surrounding 2 academic medical centers. There will be 90 preterm infants enrolled in this study born at <29 weeks of gestation. SPEEDI is a developmental intervention provided by collaboration between a physical therapist and parent to support a child's motor and cognitive development. The primary outcome measure is the Bayley Scale of Infant and Toddler Development Cognitive and Gross Motor Scaled Scores. Secondary measures include behavioral coding of early problem solving skills, the Gross Motor Function Measure, and Test of Infant Motor Performance.

IMPACT

More than 270,000 infants are born very preterm in the United States each year, 50% of whom will have neurological dysfunction that limits their ability to keep pace with peers who are typically developing. This study is a step toward understanding the impact that intensive developmental intervention could have in this population in the first months of life.

Maternal object naming is less adapted to preterm infants' than to term infants' word mapping

BACKGROUND

Term infants learn word-object relations in their first year during multisensory interactions with caregivers. Although preterm infants often experience language delays, little is known about how caregivers contribute to their early word-object learning. The present longitudinal study compared maternal naming and word learning in these infant groups.

METHODS

Forty moderately preterm and 40 term infants participated at 6-9 and 12 months with their mothers. At each visit, mothers named two novel objects during play, and infants' learning was assessed using dynamic displays of the familiar and novel (mismatched) word-object relations. Infants' general cognitive, language, and motoric abilities were evaluated. Maternal multisensory naming was coded for synchrony between the target words and object motions and other naming styles.

RESULTS

During play, although overall maternal naming-style was similar across infant groups within visits, naming frequency increased to term but not preterm infants, from visit 1 to 2. On the test at visit 1, although the term infants' looked equally to novel and familiar word-object relations, their looking to the novel relations correlated positively with maternal synchrony use but inversely with naming frequency. At visit 2, term infants looked longer to the novel relations. In contrast, preterm infants showed no looking preference at either visit. Neither was their word-object learning correlated with maternal naming. Their cognition, language, and motor scores were attenuated when compared to term infants on the Bayley-III but not their MCDI vocabulary.

CONCLUSIONS

Less adaptive maternal naming and delayed word mapping in moderately preterm infants underscore a critical need for multisensory language intervention prior to first-word onset to alleviate its cascading effects on later language.

Training attention control of very preterm infants: protocol for a feasibility study of the Attention Control Training (ACT)

BACKGROUND

Children born preterm may display cognitive, learning, and behaviour difficulties as they grow up. In particular, very premature birth (gestation age between 28 and less than 32 weeks) may put infants at increased risk of intellectual deficits and attention deficit disorder. Evidence suggests that the basis of these problems may lie in difficulties in the development of executive functions. One of the earliest executive functions to emerge around 1 year of age is the ability to control attention. An eye-tracking-based cognitive training programme to support this emerging ability, the Attention Control Training (ACT), has been developed and tested with typically developing infants. The aim of this study is to investigate the feasibility of using the ACT with healthy very preterm (VP) infants when they are 12 months of age (corrected age). The ACT has the potential to address the need for supporting emerging cognitive abilities of VP infants with an early intervention, which may capitalise on infants' neural plasticity.

METHODS/DESIGN

The feasibility study is designed to investigate whether it is possible to recruit and retain VP infants and their families in a randomised trial that compares attention and social attention of trained infants against those that are exposed to a control procedure. Feasibility issues include the referral/recruitment pathway, attendance, and engagement with testing and training sessions, completion of tasks, retention in the study, acceptability of outcome measures, quality of data collected (particularly, eye-tracking data). The results of the study will inform the development of a larger randomised trial.

DISCUSSION

Several lines of evidence emphasise the need to support emerging cognitive and learning abilities of preterm infants using early interventions. However, early interventions with preterm infants, and particularly very preterm ones, face difficulties in recruiting and retaining participants. These problems are also augmented by the health vulnerability of this population. This feasibility study will provide the basis for informing the implementation of an early cognitive intervention for very preterm infants.

TRIAL REGISTRATION

Registered Registration ID: NCT03896490. Retrospectively registered at Clinical Trials Protocol Registration and Results System (clinicaltrials.gov).

Face detection in 2- to 6-month-old infants is influenced by gaze direction and species

Humans detect faces efficiently from a young age. Face detection is critical for infants to identify and learn from relevant social stimuli in their environments. Faces with eye contact are an especially salient stimulus, and attention to the eyes in infancy is linked to the emergence of later sociality. Despite the importance of both of these early social skills-attending to faces and attending to the eyes-surprisingly little is known about how they interact. We used eye tracking to explore whether eye contact influences infants' face detection. Longitudinally, we examined 2-, 4-, and 6-month-olds' (N = 65) visual scanning of complex image arrays with human and animal faces varying in eye contact and head orientation. Across all ages, infants displayed superior detection of faces with eye contact; however, this effect varied as a function of species and head orientation. Infants were more attentive to human than animal faces and were more sensitive to eye and head orientation for human faces compared to animal faces. Unexpectedly, human faces with both averted heads and eyes received the most attention. This pattern may reflect the early emergence of gaze following-the ability to look where another individual looks-which begins to develop around this age. Infants may be especially interested in averted gaze faces, providing early scaffolding for joint attention. This study represents the first investigation to document infants' attention patterns to faces systematically varying in their attentional states. Together, these findings suggest that infants develop early, specialized functional conspecific face detection.

Infant Visual Attention and Stimulus Repetition Effects on Object Recognition

This study examined behavioral, heart rate (HR), and event-related potential (ERP) correlates of attention and recognition memory for 4.5-, 6-, and 7.5-month-old infants (N = 45) during stimulus encoding. Attention was utilized as an independent variable using HR measures. The Nc ERP component associated with attention and the late slow wave (LSW) associated with recognition memory were analyzed. The 7.5-month-olds demonstrated a significant reduction in Nc amplitude with stimulus repetition. This reduction in Nc was not found for younger infants. Additionally, infants only demonstrated differential LSW amplitude based on stimulus type on attentive trials as defined by HR changes. These findings indicate that from 4.5 to 7.5 months, infants' attentional engagement is influenced by an increasingly broader range of stimulus characteristics.

Beyond the Bayley: Neurocognitive Assessments of Development During Infancy and Toddlerhood

The use of global, standardized instruments is conventional among clinicians and researchers interested in assessing neurocognitive development. Exclusively relying on these tests for evaluating effects may underestimate or miss specific effects on early cognition. The goal of this review is to identify alternative measures for possible inclusion in future clinical trials and interventions evaluating early neurocognitive development. The domains included for consideration are attention, memory, executive function, language, and socioemotional development. Although domain-based tests are limited, as psychometric properties have not yet been well-established, this review includes tasks and paradigms that have been reliably used across various developmental psychology laboratories.

Number, time, and space are not singularly represented: Evidence against a common magnitude system beyond early childhood

Our ability to represent temporal, spatial, and numerical information is critical for understanding the world around us. Given the prominence of quantitative representations in the natural world, numerous cognitive, neurobiological, and developmental models have been proposed as a means of describing how we track quantity. One prominent theory posits that time, space, and number are represented by a common magnitude system, or a common neural locus (i.e., Bonn & Cantlon in Cognitive Neuropsychology, 29(1/2), 149-173, 2012; Cantlon, Platt, & Brannon in Trends in Cognitive Sciences, 13(2), 83-91, 2009; Meck & Church in Animal Behavior Processes, 9(3), 320, 1983; Walsh in Trends in Cognitive Sciences, 7(11), 483-488, 2003). Despite numerous similarities in representations of time, space, and number, an increasing body of literature reveals striking dissociations in how each quantity is processed, particularly later in development. These findings have led many researchers to consider the possibility that separate systems may be responsible for processing each quantity. This review will analyze evidence in favor of a common magnitude system, particularly in infancy, which will be tempered by counter evidence, the majority of which comes from experiments with children and adult participants. After reviewing the current data, we argue that although the common magnitude system may account for quantity representations in infancy, the data do not provide support for this system throughout the life span. We also identify future directions for the field and discuss the likelihood of the developmental divergence model of quantity representation, like that of Newcombe (Ecological Psychology, 2, 147-157, 2014), as a more plausible account of quantity development.

Infants Discriminate the Affective Expressions of their Peers: The Roles of Age and Familiarization Time

Research examining infants' discrimination of affect often uses unfamiliar faces and voices of adults. Recently, research has examined infant discrimination of affect in familiar faces and voices. In much of this research, infants were habituated to the affective expressions using a "standard" 50% habituation criterion. We extend this line of research by examining infants' discrimination of unfamiliar peers', that is, 4-month-olds, dynamic, facial, and vocal affective expressions and assessing how discrimination is affected by changing the habituation criterion. In two experiments, using an infant-controlled habituation design, we explored 3- and 5-month-olds' discrimination of their peers' dynamic audiovisual displays of positive and negative expressions of affect. Results of Experiment 1, using a 50% habituation criterion, revealed that 5-month-olds, but not 3-month-olds discriminated the affective expressions of their peers. In Experiment 2, we examined whether 3-month-olds' lack of discrimination in Experiment 1 was a result of insufficient habituation (i.e., familiarization). Specifically, 3-month-olds were habituated using a 70% habituation criterion, providing them with longer familiarization time. Results revealed that using the more stringent habituation criterion, 3-month-olds showed longer habituation times, that is increased familiarization, and discriminated their peers' affective expressions. Results are discussed in terms of infants' discrimination of affect, the role of familiarization time, and limitations of the 50% habituation criterion.

The manual orienting response habituation to repeated tactile stimuli in preterm neonates: Discrimination of stimulus locations and interstimulus intervals

Preterm infants frequently develop atypical sensory profiles, the tactile modality being particularly affected. However, there is a lack of recent investigation of neonatal tactile perception in a passive context, especially in preterms who are particularly exposed to this tactile stimuli. Our aims were to provide evidence of orienting responses (behavioral modifications directing subject's attention towards stimuli) and habituation to passive tactile stimuli in preterm neonates, to explore their ability to perceive spatial and temporal aspects of the stimulus, and to evaluate the effect of clinical factors on these abilities. We included 61 preterm neonates, born between 32 and 34 weeks of gestational age. At 35 weeks of corrected gestational age, we measured orienting responses (forearm, hand, and fingers movements) during vibrotactile stimulation of their hand and forearm; during a habituation and dishabituation paradigm, the dishabituation being either a location change or a pause in the stimulation sequence. Preterm newborns displayed a manual orienting response to vibrotactile stimuli which significantly decreased when the stimulus was repeated, regardless of the stimulated location on the limb. Habituation was delayed in subjects born at a younger gestational age, smaller birth weight, and having experienced more painful care procedures. Preterm neonates perceived changes in stimulus location and interstimulus time interval. Our findings provide insights on several aspects of the perception of repeated tactile stimuli by preterm neonates, and the first evidence of the early development of temporal processing abilities in the tactile modality. Future work will investigate the links between this ability and neurodevelopmental disorders.

Maturation constrains the effect of exposure in linking language and thought: evidence from healthy preterm infants

The power of human language rests upon its intricate links to human cognition. By 3 months of age, listening to language supports infants' ability to form object categories, a building block of cognition. Moreover, infants display a systematic shift between 3 and 4 months - a shift from familiarity to novelty preferences - in their expression of this link between language and core cognitive processes. Here, we capitalize on this tightly-timed developmental shift in fullterm infants to assess (a) whether it also appears in preterm infants and (b) whether it reflects infants' maturational status or the duration of their postnatal experience. Healthy late preterm infants (N = 22) participated in an object categorization task while listening to language. Their performance, coupled with that of fullterm infants, reveals that this developmental shift is evident in preterm infants and unfolds on the same maturational timetable as in their fullterm counterparts.

The Interplay Between Early Father Involvement and Neonatal Medical Risk in the Prediction of Infant Neurodevelopment

The current study examines the association between early father involvement and infant neurodevelopment, and whether neonatal medical risk moderates this association. Data from approximately 6000 fathers and their children were obtained from the Early Childhood Longitudinal Study: Birth Cohort (ECLS-B). Hierarchical regression was employed to analyze the data. The findings reveal that the association between early father involvement and infant neurodevelopment is contingent on both the timing of involvement (i.e., prenatal/perinatal or infancy) and offspring medical status at birth. The neurodevelopment of medically at-risk neonates was enhanced when fathers were involved during the gestational period and at the time of their birth. This relationship was not detected, however, in the case of infants who did not experience medical risks as neonates. Neonatal medical risk appears to be an important moderating factor in the link between father involvement during pregnancy and childbirth and infant neurodevelopment. Practitioners should continue to make efforts to involve fathers during gestation and childbirth. The findings of the present study suggest that doing so may protect against neurodevelopmental delays in neonates with medical risks.

Multiple Biomarkers of Maternal Iron Predict Infant Cognitive Outcomes

This study examined relations between multiple measures of maternal iron status assessed 3 months post-partum, and infant processing speed (longest look during visual habituation), memory (novelty preference), attention (heart rate changes), and neural response variability (in auditory event-related potentials) at 3 and 9 months. Plasma iron was associated with 9-month novelty preference and longest look, and developmental changes in longest look. Hemoglobin predicted sustained attention, and both plasma iron and soluble transferrin receptors predicted neural response variability at 9 months. Improved maternal iron appears to have a positive impact on infant cognitive development even in a well-nourished, low-risk sample.

Plasticity may change inputs as well as processes, structures, and responses

Significant work has documented neuroplasticity in development, demonstrating that developmental pathways are shaped by experience. Plasticity is often discussed in terms of the results of differences in input; differences in brain structures, processes, or responses reflect differences in experience. In this paper, I discuss how developmental plasticity also effectively changes input into the system. That is, structures and processes change in response to input, and those changed structures and processes influence future inputs. For example, plasticity may change the pattern of eye movements to a stimulus, thereby changing which part of the scene becomes the input. Thus, plasticity is not only seen in the structures and processes that result from differences in experience, but also is seen in the changes in the input as those structures and processes adapt. The systematic study of the nature of experience, and how differences in experience shape learning, can contribute to our understanding of neuroplasticity in general.

Applications of Dynamic Systems Theory to Cognition and Development: New Frontiers

A central goal in developmental science is to explain the emergence of new behavioral forms. Researchers consider potential sources of behavioral change depending partly on their theoretical perspective. This chapter reviews one perspective, dynamic systems theory, which emphasizes the interactions among multiple components to drive behavior and developmental change. To illustrate the central concepts of dynamic systems theory, we describe empirical and computational studies from a range of domains, including motor development, the Piagetian A-not-B task, infant visual recognition, visual working memory capacity, and language learning. We conclude by advocating for a broader application of dynamic systems approaches to understanding cognitive and behavioral development, laying out the remaining barriers we see and suggested ways to overcome them.

Deficits in Top-Down Sensory Prediction in Infants At Risk due to Premature Birth

A prominent theoretical view is that the brain is inherently predictive [1, 2] and that prediction helps drive the engine of development [3, 4]. Although infants exhibit neural signatures of top-down sensory prediction [5, 6], in order to establish that prediction supports development, it must be established that deficits in early prediction abilities alter trajectories. We investigated prediction in infants born prematurely, a leading cause of neuro-cognitive impairment worldwide [7]. Prematurity, independent of medical complications, leads to developmental disturbances [8-12] and a broad range of developmental delays [13-17]. Is an alteration in early prediction abilities the common cause? Using functional near-infrared spectroscopy (fNIRS), we measured top-down sensory prediction in preterm infants (born <33 weeks gestation) before infants exhibited clinically identifiable developmental delays (6 months corrected age). Whereas preterm infants had typical neural responses to presented visual stimuli, they exhibited altered neural responses to predicted visual stimuli. Importantly, a separate behavioral control confirmed that preterm infants detect pattern violations at the same rate as full-terms, establishing selectivity of this response to top-down predictions (e.g., not in learning an audiovisual association). These findings suggest that top-down sensory prediction plays a crucial role in development and that deficits in this ability may be the reason why preterm infants experience altered developmental trajectories and are at risk for poor developmental outcomes. Moreover, this work presents an opportunity for establishing a neuro-biomarker for early identification of infants at risk and could guide early intervention regimens.

Temporal Dependency and the Structure of Early Looking

Although looking time is used to assess infant perceptual and cognitive processing, little is known about the temporal structure of infant looking. To shed light on this temporal structure, 127 three-month-olds were assessed in an infant-controlled habituation procedure and presented with a pre-recorded display of a woman addressing the infant using infant-directed speech. Previous individual look durations positively predicted subsequent look durations over a six look window, suggesting a temporal dependency between successive infant looks. The previous look duration continued to predict the subsequent look duration after accounting for habituation-linked declines in look duration, and when looks were separated by an inter-trial interval in which no stimulus was displayed. Individual differences in temporal dependency, the strength of associations between consecutive look durations, are distinct from individual differences in mean infant look duration. Nevertheless, infants with stronger temporal dependency had briefer mean look durations, a potential index of stimulus processing. Temporal dependency was evident not only between individual infant looks but between the durations of successive habituation trials (total looking within a trial). Finally, temporal dependency was evident in associations between the last look at the habituation stimulus and the first look at a novel test stimulus. Thus temporal dependency was evident across multiple timescales (individual looks and trials comprised of multiple individual looks) and persisted across conditions including brief periods of no stimulus presentation and changes from a familiar to novel stimulus. Associations between consecutive look durations over multiple timescales and stimuli suggest a temporal structure of infant attention that has been largely ignored in previous work on infant looking.

Poor executive functioning in children born very preterm: Using dual-task methodology to untangle alternative theoretical interpretations

Two alternative theoretical explanations have been proposed for the difficulties with executive functioning observed in children born very preterm (VP; ⩽32 weeks): a general vulnerability (i.e., in attentional and processing capacities), which has a cascading impact on increasingly complex cognitive functions, and a selective vulnerability in executive-level cognitive processes. It is difficult to tease apart this important theoretical distinction because executive functioning tasks are, by default, complex tasks. In the current study, an experimental dual-task design was employed to control for differences in task difficulty in order to isolate executive control. Participants included 50 VP children (mean age=7.29 years) and 39 term peer controls (mean age=7.28 years). The VP group exhibited a greater dual-task cost relative to controls despite experimental control for individual differences in baseline ability on the component single tasks. This group difference also remained under a condition of reduced task difficulty. These results suggest a selective vulnerability in executive-level processes that can be separated from any general vulnerability.

Developmental improvements in the resolution and capacity of visual working memory share a common source

The nature of visual working memory (VWM) representations is currently a source of debate between characterizations as slot-like versus a flexibly-divided pool of resources. Recently, a dynamic neural field model has been proposed as an alternative account that focuses more on the processes by which VWM representations are formed, maintained, and used in service of behavior. This dynamic model has explained developmental increases in VWM capacity and resolution through strengthening excitatory and inhibitory connections. Simulations of developmental improvements in VWM resolution suggest that one important change is the accuracy of comparisons between items held in memory and new inputs. Thus, the ability to detect changes is a critical component of developmental improvements in VWM performance across tasks, leading to the prediction that capacity and resolution should correlate during childhood. Comparing 5- to 8-year-old children's performance across color discrimination and change detection tasks revealed the predicted correlation between estimates of VWM capacity and resolution, supporting the hypothesis that increasing connectivity underlies improvements in VWM during childhood. These results demonstrate the importance of formalizing the processes that support the use of VWM, rather than focusing solely on the nature of representations. We conclude by considering our results in the broader context of VWM development.

Introduction of the Utrecht Tasks for Attention in Toddlers Using Eye Tracking (UTATE): A Pilot Study

Attention capacities underlie everyday functioning from an early age onwards. Little is known about attentional processes at toddler age. A feasible assessment of attention capacities at toddler age is needed to allow further study of attention development. In this study, a test battery is piloted that consists of four tasks which intend to measure the attention systems orienting, alerting, and executive attention: the Utrecht Tasks of Attention in Toddlers using Eye tracking [UTATE]. The UTATE assesses looking behavior that may reflect visual attention capacities, by using eye-tracking methods. This UTATE was studied in 16 Dutch 18-month-old toddlers. Results showed that the instrument is feasible and generates good quality data. A first indication of sufficient reliability was found for most of the variables. It is concluded that the UTATE can be used in further studies. Further evaluation of the reliability and validity of the instrument in larger samples is worthwhile.

Aspects of Attention in Rett Syndrome

BACKGROUND

We sought to examine fundamental aspects of attention in children with Rett syndrome, a severely disabling neurodevelopmental disorder caused by spontaneous mutations in the X-linked MECP2 gene. To gauge their attention, we used eye tracking, which bypasses the profound impairments in expressive language and hand use in Rett syndrome. We report two aspects of attention-shifting and sustaining-basic abilities known to drive cognitive growth.

METHODS

Two groups were compared: those with Rett syndrome (N = 20; 3-15 years) and a typically developing comparison group (N = 14; 3-16 years), using a task in which an attractive central stimulus was followed, after a short gap, by a dynamic target presented to one side. Time to shift to the target location (reactive and anticipatory saccades) and time fixating the target were assessed.

RESULTS

Children with Rett syndrome were consistently slower to shift (largely because of fewer anticipations); their reactive saccades were also slower than those of typically developing children, but not significantly so. The Rett syndrome group spent considerable time looking at the target (over 75% of available time), although significantly less so than the typically developing group.

CONCLUSIONS

These findings indicate that children with Rett syndrome could maintain attention on a stimulus and orient relatively quickly to the appearance of a target in the visual field. However, they had difficulty in anticipating predictable events, a difficulty in endogenous attention that is likely to have deleterious implications for executive functioning.

Poorer divided attention in children born very preterm can be explained by difficulty with each component task, not the executive requirement to dual-task

Children born very preterm (VP, ≤ 32 weeks) exhibit poor performance on tasks of executive functioning. However, it is largely unknown whether this reflects the cumulative impact of non-executive deficits or a separable impairment in executive-level abilities. A dual-task paradigm was used in the current study to differentiate the executive processes involved in performing two simple attention tasks simultaneously. The executive-level contribution to performance was indexed by the within-subject cost incurred to single-task performance under dual-task conditions, termed dual-task cost. The participants included 77 VP children (mean age: 7.17 years) and 74 peer controls (mean age: 7.16 years) who completed Sky Search (selective attention), Score (sustained attention) and Sky Search DT (divided attention) from the Test of Everyday Attention for Children. The divided-attention task requires the simultaneous performance of the selective- and sustained-attention tasks. The VP group exhibited poorer performance on the selective- and divided-attention tasks, and showed a strong trend toward poorer performance on the sustained-attention task. However, there were no significant group differences in dual-task cost. These results suggest a cumulative impact of vulnerable lower-level cognitive processes on dual-tasking or divided attention in VP children, and fail to support the hypothesis that VP children show a separable impairment in executive-level abilities.

Factor Structure of Attention Capacities Measured With Eye-Tracking Tasks in 18-Month-Old Toddlers

OBJECTIVE

Attention capacities are critical for adaptive functioning and development. Reliable assessment measures are needed for the study of attention capacities in early childhood. In the current study, we investigated the factor structure of the Utrecht Tasks of Attention in Toddlers Using Eye-tracking (UTATE) test battery that assesses attention capacities in 18-month-old toddlers with eye-tracking techniques.

METHOD

The factor structure of 13 measures of attention capacities, based on four eye-tracking tasks, was investigated in a sample of 95 healthy toddlers (18 months of age) using confirmatory factor analysis.

RESULTS

Results showed that a three-factor model best fitted the data. The latent constructs reflected an orienting, alerting, and executive attention system.

CONCLUSION

This study showed support for a three-factor model of attention capacities in 18-month-old toddlers. Further study is needed to investigate whether the model can also be used with children at risk of attention problems.

Efficient human face detection in infancy

Adults detect conspecific faces more efficiently than heterospecific faces; however, the development of this own-species bias (OSB) remains unexplored. We tested whether 6- and 11-month-olds exhibit OSB in their attention to human and animal faces in complex visual displays with high perceptual load (25 images competing for attention). Infants (n = 48) and adults (n = 43) passively viewed arrays containing a face among 24 non-face distractors while we measured their gaze with remote eye tracking. While OSB is typically not observed until about 9 months, we found that, already by 6 months, human faces were more likely to be detected, were detected more quickly (attention capture), and received longer looks (attention holding) than animal faces. These data suggest that 6-month-olds already exhibit OSB in face detection efficiency, consistent with perceptual attunement. This specialization may reflect the biological importance of detecting conspecific faces, a foundational ability for early social interactions.

Face-n-Food: Gender Differences in Tuning to Faces

Faces represent valuable signals for social cognition and non-verbal communication. A wealth of research indicates that women tend to excel in recognition of facial expressions. However, it remains unclear whether females are better tuned to faces. We presented healthy adult females and males with a set of newly created food-plate images resembling faces (slightly bordering on the Giuseppe Arcimboldo style). In a spontaneous recognition task, participants were shown a set of images in a predetermined order from the least to most resembling a face. Females not only more readily recognized the images as a face (they reported resembling a face on images, on which males still did not), but gave on overall more face responses. The findings are discussed in the light of gender differences in deficient face perception. As most neuropsychiatric, neurodevelopmental and psychosomatic disorders characterized by social brain abnormalities are sex specific, the task may serve as a valuable tool for uncovering impairments in visual face processing.

Early language processing efficiency predicts later receptive vocabulary outcomes in children born preterm

As rates of prematurity continue to rise, identifying which preterm children are at increased risk for learning disabilities is a public health imperative. Identifying continuities between early and later skills in this vulnerable population can also illuminate fundamental neuropsychological processes that support learning in all children. At 18 months adjusted age, we used socioeconomic status (SES), medical variables, parent-reported vocabulary, scores on the Bayley Scales of Infant and Toddler Development (third edition) language composite, and children's lexical processing speed in the looking-while-listening (LWL) task as predictor variables in a sample of 30 preterm children. Receptive vocabulary as measured by the Peabody Picture Vocabulary Test (fourth edition) at 36 months was the outcome. Receptive vocabulary was correlated with SES, but uncorrelated with degree of prematurity or a composite of medical risk. Importantly, lexical processing speed was the strongest predictor of receptive vocabulary (r = -.81), accounting for 30% unique variance. Individual differences in lexical processing efficiency may be able to serve as a marker for information processing skills that are critical for language learning.

Very preterm children are at increased risk of reduced processing speed at 5 years of age, predicted by typical complications of prematurity and prenatal smoking

AIM

Very little is known about risk predictors for the development of reduced processing speed, which can cause intellectual problems in later life. This study identified risk predictors at 5 years of age in a population-based cohort of very preterm infants.

METHODS

Between January 2003 and August 2006, all preterm infants born before 32 weeks of gestation in Tyrol were prospectively enrolled (n = 223), and 161 underwent a detailed examination at 5 years of age, including a cognitive assessment using the Wechsler Preschool and Primary Scale of Intelligence, third edition. The processing speed quotient is calculated on the basis of two subtests that assess symbol search and coding. The association between prenatal and postnatal factors and reduced processing speed was analysed by means of logistic regression analysis.

RESULTS

Of 161 children tested, 55 (34.2%) showed reduced processing speed. In 55.6% (n = 30) of these children, reduced processing speed was related to full-scale intelligence quotient scores of <85. Smoking in pregnancy, steroids for chronic lung disease and intracerebral haemorrhage predicted reduced processing speed at 5 years of age.

CONCLUSION

More than a third of the very preterm children we tested showed reduced processing speed at 5 years of age, and predictors were typical complications of prematurity and smoking in pregnancy.