Cognitive Developmental Trajectories Research Articles

Examining behavioral settings and affordative space for the case of autism spectrum conditions in embodied cognition

ABSTRACT The aim of the paper is to deepen into a theoretical account on the role of behavioral settings and relational affordative space and how this perspective can be used to reconceptualize various human cognitive developmental trajectories and conditions. In the course of this theoretical work, we want to contribute in rethinking developmental trajectories based on the role of behavioral settings and relational affordances from an embodied perspective. Behavioral settings emerge from joint actions in conjunction with the affordances available. These affordances will have multiple levels and kinds of meanings for the organism which is why we need to distinguish between the general affordances for a form of life and the particular affordances for particular agents that are generated through sensorimotor interactions. We propose to apply this theoretical frame in different developmental conditions, taking as a leading example the Autistic Spectrum, extending it to other lived experiences of other groups marginalized by “normative behavioral settings” – and the ensuing ethical concerns.

Understanding the pubertal, psychosocial, and cognitive developmental trajectories of stunted and non-stunted adolescents: protocol of a multi-site Indonesian cohort study.

The prevalence of stunting among Indonesian children aged 5-12 years decreased from 30.7% in 2013 to 23.6% in 2018 but has remained among the highest rates worldwide. Furthermore, Indonesian children were shorter than the standard reported by the World Health Organization and experienced obesity. The Indonesian government has created many programs to reduce stunting in children under the age of 5 years. An early preventive strategy is necessary because stunting can manifest within the initial 1,000 days of life, including during pregnancy. Therefore, a newer perspective, such as that achieved by addressing stunting in adolescents, has been deemed useful, given that adolescents are in their pubertal stage and are undergoing lifestyle changes. This cohort study was designed to measure these factors comprehensively in stunted and non-stunted children as they pass through adolescence. For the prospective cohort, 560 individuals will be recruited from DKI Jakarta, DI Yogyakarta, and East Java. The participants will be categorized into stunted and non-stunted groups, then undergo annual examinations in which key objectives, such as weight, height, and body mass index ,will be assessed for the growth profile; waist circumference, middle-upper arm circumference, hand-grip strength, body fat percentage, and food intake will be evaluated in a nutritional assessment; psychosocial and mental issues will be evaluated according to behavioral problems, symptoms of depression, quality of life, sleep patterns, anxiety disorders, and parenting style through the use of specific questionnaires; and pubertal stage will be assessed using a self-report questionnaire. Some cross-sectional data, such as cognitive performance, hair zinc levels, vitamin D levels, bone mineral density, and bone age, will also be included. All the outcomes will be analyzed in accordance with the variable types. This study provides a thorough dataset of Indonesian adolescents encompassing several elements, such as growth, nutrition, psychosocial wellbeing, mental health, and pubertal development, for both stunted and non-stunted individuals. The data acquired from this study can be used to formulate policies to prevent stunting through targeted interventions for adolescents. Finally, a better understanding of adolescent health could lead to improved strategies to decrease the number of stunted individuals in the next Indonesian generation.

Iron status in early infancy is associated with trajectories of cognitive development up to pre-school age in rural Gambia.

Iron deficiency is among the leading risk factors for poor cognitive development. However, interventions targeting iron deficiency have had mixed results on cognitive outcomes. This may be due to previous interventions focusing on the correction of iron deficiency anaemia in late infancy and early childhood, at which point long lasting neural impacts may already be established. We hypothesise that the relationship between iron status and cognitive development will be observable in the first months of life and will not be recovered by 5 years of age. Using data from the Brain Imaging for Global Health (BRIGHT) Study in Gambia (n = 179), we conducted mixed effects modelling to assess the relationship between iron status at 5 months of age and trajectories of cognitive development from 5 months- 5 years using (i) a standardised measure of cognitive development (Mullen Scales of Early Learning) and (ii) an eye-tracking assessment of attention processing (visual disengagement time). All infants were iron sufficient at 1 month of age. At 5 and 12 months of age 30% and 55% of infants were iron deficient respectively. In fully adjusted analyses, infants in the lowest tercile of soluble transferrin receptor (sTfR) (best iron status) achieved MSEL Cognitive Scores on average 1.9 points higher than infants in the highest sTfR tercile (p = 0.009, effect size = 0.48). There was no evidence that this group difference was recovered by 5 years of age. Infants in the lowest sTfR tercile had visual disengagement time 57ms faster than the highest tercile (p = 0.001, effect size = 0.59). However, this difference diminished by early childhood (p = 0.024). Infants are at risk of iron deficiency in early infancy. A relationship between iron status and cognitive development is apparent from 5 months of age and remains observable at 5 years of age. One mechanism by which iron availability in early infancy impacts brain development may be through effects on early attentional processing, which is rapidly developing and has substantial nutritional requirements during this period. To support neurocognitive development, prevention of iron deficiency in pre- and early postnatal life may be more effective than correcting iron deficiency once already established.

Mind the gap: trajectory of cognitive development in young individuals with sickle cell disease: a cross-sectional study.

Compared to typically developing children and young adults (CYA-TD), those living with Sickle Cell Disease (CYA-SCD) experience more cognitive difficulties, particularly with executive function. Few studies have examined the relative importance of silent cerebral infarction (SCI), haemoglobin and arterial oxygen content on age-related cognitive changes using cross-sectional or longitudinal (developmental trajectory) data. This study presents cohort data from a single timepoint to inform studies with multiple timepoints. We compared cross-sectional raw and scaled scores as age-related changes in cognition (trajectories) in CYA-SCD and age-and ethnicity-matched CYA-TD. We also compared cross-sectional age-related changes in cognition (trajectories) in CYA-SCD with and without SCI to CYA-TD. General cognitive abilities were assessed using Wechsler Intelligence Scales, including the Verbal Comprehension Index (VCI) and Perceptual Reasoning Index (PRI) underpinning IQ. Executive function was evaluated using the Delis-Kaplan Executive Function System (D-KEFS) Tower subtest and the Behaviour Rating Inventory of Executive Function (BRIEF) questionnaire. SCI were identified from contemporaneous 3 T MRI; participants with overt stroke were excluded. Recent haemoglobin was available and oxygen saturation (SpO2) was measured on the day of the MRI. Data were available for 120 CYA-SCD [62 male; age = 16.78 ± 4.79 years; 42 (35%) with SCI] and 53 CYA-TD (23 male; age = 17.36 ± 5.16). Compared with CYA-TD, CYA-SCD experienced a delayed onset in VCI and slower rate of development for BRIEF Global Executive Composite, Metacognition Index (MI), and Behaviour Regulation Index. The rate of executive function development for the BRIEF MI differed significantly between CYA-TD and CYA-SCD, with those with SCI showing a 26% delay compared with CYA-TD. For CYA-SCD with SCI, arterial oxygen content explained 22% of the variance in VCI and 37% in PRI, while haemoglobin explained 29% of the variance in PRI. Age-related cognitive trajectories of CYA-SCD may not be impaired but may progress more slowly. Longitudinal studies are required, using tests unaffected by practice. In addition to initiation of medical treatment, including measures to improve arterial oxygen content, early cognitive intervention, educational support, and delivery of extracurricular activities could support cognitive development for CYA-SCD.Graphical Abstract.

Replies

Replies

Longitudinal analysis of cognitive development across childhood and adolescence: evidence from the UK Millennium Cohort Study

BackgroundPoor cognitive ability in childhood may lead to poor outcomes across the life course. Thus, isolating clusters of children who share similar trajectories of cognitive development across the childhood developmental stages will facilitate the development of more precise interventions. This study sought to identify trajectories of cognitive development across childhood and early-adolescence. We then aimed to assess associations of these trajectories with demographic factors, socioeconomic circumstances, parenting and school environment. MethodWe used data from the UK Millennium Cohort study on 11564 children aged between 3 and 14 years. Cognitive development was assessed through standard cognition tests administered individually to cohort members at ages 3, 5, 7, 11, and 14 years. The British Ability Scales II tests were used at ages 3–11 years and a word activity test at age 14 years. Standardised test scores were used to classify children into two groups to create a binary measure with children classified as having cognitive problems if they scored –1·25 SDs below the cohort mean. We used a group-based trajectory model to identify trajectories of cognitive development for children. Multinomial regression models were used to assess associations. FindingsFour trajectories were identified: early childhood cognitive problems (719 [6·2%] of sample), late childhood cognitive problems (1084 [9·4%]), persistent cognitive problems (498 [4·3%]) and low cognitive problems (9263 [80·1%]). In the multivariable regression analysis increasing deprivation, low maternal education and low parental involvement with school increased the risk of being in all of the problem groups compared with children with low cognitive problems. Males, being bullied and those of non-White ethnicity had an increased risk of being in the persistent problems group. Males, not being read to and those of non-White ethnicity had an increased risk of being in the early problems group. Females, being bullied and not enjoying school had an increased risk of being in the late problems group. InterpretationDeprivation is associated with cognitive problems throughout childhood. Gender, ethnicity, the school environment, and aspects of parenting are associated with cognitive problems at different stages of childhood. These findings highlight possible targets for interventions. Using a contemporary nationally representative UK cohort, to identify characteristics of children with similar trajectories of cognitive development, strengthens generalisability of findings to inform UK policy. FundingUK National Institute for Health Research Doctoral Research Fellowship Programme.

Longitudinal Cognitive Assessment in Low-Risk Very Preterm Infants.

Background and Objectives: Preterm infants are at higher risk of neurodevelopmental impairment both at preschool and school ages, even in the absence of major neurological deficits. The early identification of children at risk is essential for early intervention with rehabilitation to optimize potential outcomes during school years. The aim of our study is to assess cognitive outcomes at preschool age in a cohort of low-risk very preterm infants, previously studied at 12 and 24 months using the Griffiths scales. Materials and Methods: Sixty-six low-risk very preterm infants born at a gestational age of <32 weeks were assessed at 12 and 24 months corrected age using the Griffiths Mental Development Scales (second edition) and at preschool age with the Wechsler Preschool and Primary Scales of Intelligence (third edition) (WPPSI-III). Results: At 12 and 24 months and at preschool age, low-risk very preterm infants showed scores within normal ranges with similar scores in males and females. A statistically significant correlation was observed in the general developmental quotient between 12 and 24 months; a further significant correlation was observed between the early cognitive assessments and those performed at preschool age, with a better correlation using the assessments at 24 months. Conclusion: The present study showed a favourable trajectory of cognitive development in low-risk very preterm infants, from 12 months to preschool age.

Cognitive behavioral markers of neurodevelopmental trajectories in rodents

Between adolescence and adulthood, the brain critically undergoes maturation and refinement of synaptic and neural circuits that shape cognitive processing. Adolescence also represents a vulnerable period for the onset of symptoms in neurodevelopmental psychiatric disorders. Despite the wide use of rodent models to unravel neurobiological mechanisms underlying neurodevelopmental disorders, there is a surprising paucity of rigorous studies focusing on normal cognitive-developmental trajectories in such models. Here, we sought to behaviorally capture maturational changes in cognitive trajectories during adolescence and into adulthood in male and female mice using distinct behavioral paradigms. C57 BL/6J mice (4.5, 6, and 12 weeks of age) were assessed on three behavioral paradigms: drug-induced locomotor hyperactivity, prepulse inhibition, and a novel validated version of a visuospatial paired-associate learning touchscreen task. We show that the normal maturational trajectories of behavioral performance on these paradigms are dissociable. Responses in drug-induced locomotor hyperactivity and prepulse inhibition both displayed a ‘U-shaped’ developmental trajectory; lower during mid-adolescence relative to early adolescence and adulthood. In contrast, visuospatial learning and memory, memory retention, and response times indicative of motivational processing progressively improved with age. Our study offers a framework to investigate how insults at different developmental stages might perturb normal trajectories in cognitive development. We provide a brain maturational approach to understand resilience factors of brain plasticity in the face of adversity and to examine pharmacological and non-pharmacological interventions directed at ameliorating or rescuing perturbed trajectories in neurodevelopmental and neuropsychiatric disorders.

Developmental trajectories and brain correlates of directed forgetting in 22q11.2 deletion syndrome

22q11.2 deletion syndrome (22q11DS), also known as velo-cardio-facial syndrome (VCFS) is the most common copy number variant (CNV) in humans caused by a microdeletion on chromosome 22q11.2. The phenotype encompasses heart anomalies, cleft palate and cognitive difficulties. Alongside brain differences in VCFS, such as reduced hippocampal volume, different cognitive developmental trajectories can be observed. The aim of this study was to explore the developmental trajectories of cognitive inhibition in memory using longitudinal data acquired in a large cohort of individuals with 22q11DS and the brain correlates to those developmental changes. 51 participants with 22q11DS (mean age: 13.75 ± 4.26, mean IQ score: 70.50 ± 10.75) and 43 typically developing individuals matched for age (M = 13.50 ± 4.91) and gender were recruited. To explore inhibition in memory, the Directed Forgetting paradigm was used. 30 words were presented, half were ‘To be remembered items’(TBR) and the other half ‘To be forgotten items’ (TBF). To measure source memory, participants were asked during the recognition stage to say if the world was a TBR or a TBF item. Participants were tested during two consecutive visits, with a mean interval of 3 years. T1-weighted images were acquired using a 1.5 T Philips or a 3 T Siemens scanner at both visits. Both groups recognized more TBR than TBF items (Directed forgetting effect), however, participants with 22q11DS recognized fewer TBR items and did not show an increased recognition of TBR items with age. Furthermore, in participants with VCFS increased source memory errors with age was associated with a decline in hippocampal volume.

Association between early child development trajectories and adult cognitive function in a 50-year longitudinal study in Guatemala

ObjectivesFew studies have used longitudinal data to study the development of cognition over the life course in low-income and middle-income countries. The objectives of this study were to assess predictors...

Iron Status in Early Infancy Is Associated With Attentional Flexibility and Cognitive Achievement in Rural Gambia

ObjectivesTo determine the relationship between iron status in early infancy (1–5 months) and longitudinal trajectories of cognitive development (5–18 months) in a cohort of infants from rural Gambia. MethodsThis study used data from the Brain Imaging for Global Health (BRIGHT) study, which recruited pregnant women (n = 223) and followed up mothers and their children to 18 months of age (n = 191). Infant blood samples collected at 1 and 5 months of age were analysed for soluble transferrin receptor (sTfR) and ferritin using a COBAS INTEGRA 400 (Roche). Cognitive development was measured at 5, 8, 12 and 18 months of age using the Mullen Scales of Early Learning (MSEL) and an eye tracking measure of attentional flexibility (disengagement time). For each outcome measure, mixed effects models of individual developmental trajectories from 5–18 months of age were developed. Each model had a different measure of iron status as the primary exposure (ferritin or sTfR at 1 or 5 months of age) and was adjusted for confounding factors. ResultsPrevalence of iron deficiency (ferritin < 12μg/L or < 30 μg/L if CRP > 5mg/L) increased from 0% to 29.5% between 1 and 5 months of age. In mixed effects models, a -1mg/L difference in sTfR (indicating better iron status) at 1 month of age was associated as with a 31.2ms difference in disengagement time (SE = 13.1, p = 0.017) at each time point from 5–18 months of age, but was not associated with MSEL developmental trajectory. A -1mg/L difference in sTfR at 5 months of age associated with a 0.6 point difference in MSEL score from 5–18 months of age (SE = 0.180, p = 0.001) and a 10.6ms difference in disengagement time (SE = 4.8, p = 0.028) across the same period. There was no relationship between ferritin concentration at 1 or 5 months and trajectories of either MSEL or disengagement time (all p > 0.05). ConclusionsInfants under 6 months of age in rural Gambia are at risk of iron deficiency. Poor iron status in early infancy, measured by sTfR but not ferritin, is associated with both global cognition and a specific measure of attentional flexibility, from 5–18 months of age. Maintenance of adequate iron in infants up to 6 months of age may benefit the developing brain. Funding SourcesBill and Melinda Gates Foundation and Medical Research Council (UK).

Trajectories of child cognitive development during ages 0\u20133 in rural Western China: prevalence, risk factors and links to preschool-age cognition

BackgroundCognitive development after age three tends to be stable and can therefore predict cognitive skills in later childhood. However, there is evidence that cognitive development is less stable before age three. In rural China, research has found large shares of children under age three are developmentally delayed, yet little is known about the trajectories of cognitive development between 0 and 3 years of age or how developmental trajectories predict later cognitive skills. This study seeks to describe the trajectories of child cognitive development between the ages of 0–3 years and examine how different trajectories predict cognitive development at preschool age.MethodsWe collected three waves of longitudinal panel data from 1245 children in rural Western China. Child cognitive development was measured by the Bayley Scales of Infant Development when the child was 6–12 months and 22–30 months, and by the Wechsler Preschool and Primary Scale of Intelligence-Fourth Edition when the child was 49–65 months. We used the two measures of cognitive development before age three to determine the trajectories of child cognitive development.ResultsOf the children, 39% were never cognitively delayed; 13% were persistently delayed; 7% experienced improving cognitive development; and 41% experienced deteriorating development before age 3. Compared to children who had never experienced cognitive delay, children with persistent cognitive delay and those with deteriorating development before age 3 had significantly lower cognitive scores at preschool age. Children with improving development before age 3 showed similar levels of cognition at preschool age as children who had never experienced cognitive delay.ConclusionsLarge shares of children under age 3 in rural Western China show deteriorating cognitive development from infancy to toddlerhood, which predict lower levels of cognition at preschool age. Policymakers should invest in improving cognitive development before age 3 to prevent long-term poor cognition among China’s rural children.

Design and validation of a smart garment to measure positioning practices of parents with young infants

The aim of this cross-sectional study was to evaluate the feasibility, construct validity, and reliability of a smart garment to characterize parent-child positioning practices in infants less than six months old. The smart garment (Get Around Garment, GG) was developed through feedback from seven infants and their parents. The final system was then tested with sixteen infants (M = 3.1 ± 1.1 months) assessed in their homes during one visit that consisted of a: 1) Structured Play Assessment (2.5 min): infant was placed in each of five positions (prone, supine, reclined/inclined, and upright) for 30 s, 2) Free Play Assessment (40−60 min): parents were asked to engage in typical daily activities, and 3) second Structured Play Assessment. Infants’ body position was both coded from video and identified from sensor data using a custom program. Feasibility was measured by data from a Daily Wearing Log and Garment Perception Questionnaire. Validity was evaluated by comparing the coding and sensor data. Reliability was measured by comparing the sensor data between the two Structured Play Assessments. The GG was considered feasible for use. The smart wearable system showed high levels of accuracy for classifying body position secondby- second and when comparing cumulative duration across time. Reliability of the smart garment was excellent. Young infants spent more time in supine and supported upright positions relative to prone, reclined, or inclined positions. The results suggest that accelerometers can be integrated into garments in a manner that is feasible to provide accurate and consistent data about positioning practices of parents with young infants. Monitoring early positioning practices is important because these practices impact future motor and cognitive developmental trajectories.

Development of visual attention from age 7 to age 12 in children with familial high risk for schizophrenia or bipolar disorder

BackgroundChildren with familial high risk of schizophrenia (FHR-SZ) or bipolar disorder (FHR-BP) are at increased risk of developing similar disorders and show cognitive deficits during childhood. The aim of this paper is to investigate visual attention and its developmental trajectories in children with FHR-SZ and with FHR-BP to increase our knowledge about potential cognitive endophenotypes of these two disorders. MethodsWe compared the performance of 89 children with FHR-SZ (N = 32), FHR-BP (N = 22), and population-based controls (PBC, N = 35) at age 7 to that at age 12 as well as including 133 12-year-old children with FHR-SZ (N = 50), FHR-BP (N = 43) and PBC (N = 40) to investigate visual attention, as part of the Danish High Risk and Resilience Study. We used the TVA-based whole report paradigm, based on the Bundesen's Theory of Visual Attention (TVA) to investigate visual attention. ResultsChildren with FHR-SZ that showed deficits in visual processing speed at age 7 improved to a level that was not significantly different from controls at age 12. All children improved over time. We found no attentional deficits in FHR children at age 12. ConclusionsOn visual attention, children with FHR-SZ did not show developmental deficits or lags and, together with children with FHR-BP, they develop similarly to control children between age 7 to age 12. This emphasizes the potential of beneficial neuroplastic changes in cognitive deficits found at younger ages in children with FHR-SZ. It also highlights the importance of identifying and characterizing cognitive developmental trajectories of high-risk children and provides hope that visual attention may develop appropriately in these groups.

Cognitive Developmental Trajectories in Adult ADHD Patients and Controls: A Comparative Study

Objective: There is an updated conceptualization of whole-lifespan attention-deficit hyperactivity disorder (ADHD), promoted by awareness of probable persistence of impairment into adulthood. We investigated cognition trajectories from adolescence to mid-adulthood in ADHD. Method: Data of 240 patients with ADHD and 244 healthy controls (HCs) were obtained; clinical symptoms and neuropsychological functions were assessed using the various tests. Results: Compared to HCs, patients with ADHD except 35 to 44 age interval showed lower full scale intelligence quotient. They showed decreased verbal comprehensive scores except in the 35 to 44 age interval and working memory scores in all intervals. In the Comprehensive Attention Test, patients with ADHD showed increased working memory error frequencies except in the 15 to 17 age interval and divided attention omission error in all intervals. Conclusion: Adults with ADHD showed deficits not in simple attention but in complex attention, including divided attention and working memory.

Early Life Experiences and Trajectories of Cognitive Development.

Multiple factors constrain the trajectories of child cognitive development, but the drivers that differentiate the trajectories are unknown. We examine how multiple early life experiences differentiate patterns of cognitive development over the first 5 years of life in low-and middle-income settings. Cognitive development of 835 children from the Etiology, Risk Factors, and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development (MAL-ED) multisite observational cohort study was assessed at 6, 15, 24 (Bayley Scales of Infant and Toddler Development), and 60 months (Wechsler Preschool and Primary Scale of Intelligence). Markers of socioeconomic status, infection, illness, dietary intake and status, anthropometry, and maternal factors were also assessed. Trajectories of development were determined by latent class-mixed models, and factors associated with class membership were examined by discriminant analysis. Five trajectory groups of cognitive development are described. The variables that best discriminated between trajectories included presence of stimulating and learning resources in the home, emotional or verbal responsivity of caregiver and the safety of the home environment (especially at 24 and 60 months), proportion of days (0-24 months) for which the child had diarrhea, acute lower respiratory infection, fever or vomiting, maternal reasoning ability, mean nutrient densities of zinc and phytate, and total energy from complementary foods (9-24 months). A supporting and nurturing environment was the variable most strongly differentiating the most and least preferable trajectories of cognitive development. In addition, a higher quality diet promoted cognitive development while prolonged illness was indicative of less favorable patterns of development.

Let Us Be Vigilant: COVID-19 Is Poised to Obliterate Gains in Healthy Child Development Globally

In this issue of Pediatrics , McCormick et al1 report on a multicountry observational cohort study in which children and parents were assessed multiple times from children’s age 6 months to 6 years, collecting information on measures of socioeconomic status, infection, illness, maternal depression, positive parenting, and the home environment, with the outcome being child development as measured by the Bayley Scales of Infant Development at early ages and the Wechsler Preschool and Primary Scale of Intelligence at 60 months. Five trajectories of cognitive development were determined by statistical analysis. Not surprisingly, variables that represented a supportive and nurturing environment, such as emotional-verbal responsiveness of the parents, behaviors and/or environment to support learning, and environmental safety, were most strongly able to differentiate the most and least positive trajectories. Of course, other important variables were adequate nutrition and less respiratory and diarrheal illness. There is a large literature on the relationship of interventions to support and enhance nurturing parenting as well as to improve the learning environment with better early childhood outcomes in both high-income countries and low- and middle-income countries.2–5 We also know that children living in … Address correspondence to Benard P. Dreyer, MD, FAAP, Department of Pediatrics, NYU Grossman School of Medicine, New York University, 550 First Ave, New York, NY 10016. E-mail: benard.dreyer{at}nyulangone.org

Distinct Polygenic Score Profiles in Schizophrenia Subgroups With Different Trajectories of Cognitive Development.

Different cognitive development histories in schizophrenia may reflect variation across dimensions of genetic influence. The authors derived and characterized cognitive development trajectory subgroups within a schizophrenia sample and profiled the subgroups across polygenic scores (PGSs) for schizophrenia, cognition, educational attainment, and attention deficit hyperactivity disorder (ADHD). Demographic, clinical, and genetic data were collected at the National Institute of Mental Health from 540 schizophrenia patients, 247 unaffected siblings, and 844 control subjects. Cognitive trajectory subgroups were derived through cluster analysis using estimates of premorbid and current IQ. PGSs were generated using standard methods. Associations were tested using general linear models and logistic regression. Cluster analyses identified three cognitive trajectory subgroups in the schizophrenia group: preadolescent cognitive impairment (19%), adolescent disruption of cognitive development (44%), and cognitively stable adolescent development (37%). Together, the four PGSs significantly predicted 7.9% of the variance in subgroup membership. Subgroup characteristics converged with genetic patterns. Cognitively stable individuals had the best adult clinical outcomes and differed from control subjects only in schizophrenia PGSs. Those with adolescent disruption of cognitive development showed the most severe symptoms after diagnosis and were cognitively impaired. This subgroup had the highest schizophrenia PGSs and had disadvantageous cognitive PGSs relative to control subjects and cognitively stable individuals. Individuals showing preadolescent impairment in cognitive and academic performance and poor adult outcome exhibited a generalized PGS disadvantage relative to control subjects and were the only subgroup to differ significantly in education and ADHD PGSs. Subgroups derived from patterns of premorbid and current IQ showed different premorbid and clinical characteristics, which converged with broad genetic profiles. Simultaneous analysis of multiple PGSs may contribute to useful clinical stratification in schizophrenia.

Midlife Study of the Louisville Twins: Connecting Cognitive Development to Biological and Cognitive Aging

The Louisville Twin Study (LTS) began in 1958 and became a premier longitudinal twin study of cognitive development. The LTS continuously collected data from twins through 2000 after which the study closed indefinitely due to lack of funding. Now that the majority of the sample is age 40 or older (61.36%, N = 1770), the LTS childhood data can be linked to midlife cognitive functioning, among other physical, biological, social, and psychiatric outcomes. We report results from two pilot studies in anticipation of beginning the midlife phase of the LTS. The first pilot study was a participant tracking study, in which we showed that approximately 90% of the Louisville families randomly sampled (N = 203) for the study could be found. The second pilot study consisted of 40 in-person interviews in which twins completed cognitive, memory, biometric, and functional ability measures. The main purpose of the second study was to correlate midlife measures of cognitive functioning to a measure of biological age, which is an alternative index to chronological age that quantifies age as a function of the breakdown of structural and functional physiological systems, and then to relate both of these measures to twins' cognitive developmental trajectories. Midlife IQ was uncorrelated with biological age (- .01) while better scores on episodic memory more strongly correlated with lower biological age (- .19 to - .31). As expected, midlife IQ positively correlated with IQ measures collected throughout childhood and adolescence. Additionally, positive linear rates of change in FSIQ scores in childhood significantly correlated with biological age (- .68), physical functioning (.71), and functional ability (- .55), suggesting that cognitive development predicts lower biological age, better physical functioning, and better functional ability. In sum, the Louisville twins can be relocated to investigate whether and how early and midlife cognitive and physical health factors contribute to cognitive aging.

Early life cognitive development trajectories and intelligence quotient in middle childhood and early adolescence in rural western China

The relationship of cognitive developmental trajectories during the dynamic first years with later life development outcomes remains unclear in low- and middle-income countries. 1388 Children born to women who participated in a randomized trial of antenatal micronutrient supplementation in rural China were prospectively followed. Cognitive development was assessed six times between 3 and 30 months of age using Bayley Scales of Infant Development, and then in mid-childhood (7–9 years) and early adolescence (10–12 years) using Wechsler Intelligence Scale for Children. We identified four distinct infant cognitive development trajectory subgroups using group-based trajectory modeling: (i) consistently above average, (ii) consistently average, (iii) started below average and then improved, and (iv) started below average and then declined. LBW infants (<2500 g) were 10.60 times (95% CI 3.57, 31.49) more likely to be in the trajectory group that started below average and then declined, while each grade increase in maternal education decreased the risk of being in this group by 73% (95% CI 54%, 84%). Infants who performed consistently above average had 8.02 (95% CI 1.46, 14.59) points higher IQ in adolescence versus the declining trajectory group. These findings suggest that interventions to improve early child development trajectories may produce long-term human capital benefits.