Cohort profile: the Siyakhula cohort, rural South Africa

No abstract available

An adaptation of the experiences in close relationships scale-revised for use with children and adolescents

The investigation of attachment processes during middle childhood and early adolescence has been hampered by a relative lack of measures for this age group differentiating between two fundamental attachment dimensions, that is, anxiety and avoidance. The aim of this study is to develop and validate a child version of the Experiences in Close Relationships Scale-Revised (referred to as the ECR-RC), a self-report questionnaire measuring attachment anxiety and avoidance. Two studies were conducted to examine the internal structure (Study 1, N = 514 and Study 2, N = 296) and construct and predictive validity (Study 2) of the ECR-RC. The ECR-RC appears to be a promising instrument to measure the two attachment dimensions in middle childhood and early adolescence

Automaticity in processing spatial-numerical associations: Evidence from a perceptual orientation judgment task of Arabic digits in frames.

Human adults are faster to respond to small/large numerals with their left/right hand when they judge the parity of numerals, which is known as the SNARC (spatial-numerical association of response codes) effect. It has been proposed that the size of the SNARC effect depends on response latencies. The current study introduced a perceptual orientation task, where participants were asked to judge the orientation of a digit or a frame surrounding the digit. The present study first confirmed the SNARC effect with native Chinese speakers (Experiment 1) using a parity task, and then examined whether the emergence and size of the SNARC effect depended on the response latencies (Experiments 2, 3, and 4) using a perceptual orientation judgment task. Our results suggested that (a) the automatic processing of response-related numerical-spatial information occurred with Chinese-speaking participants in the parity task; (b) the SNARC effect was also found when the task did not require semantic access; and (c) the size of the effect depended on the processing speed of the task-relevant dimension. Finally, we proposed an underlying mechanism to explain the SNARC effect in the perceptual orientation judgment task

Human metabolic adaptations and prolonged expensive neurodevelopment: A review

1.	After weaning, human hunter-gatherer juveniles receive substantial (≈3.5-7 MJ day^-1^), extended (≈15 years) and reliable (kin and nonkin food pooling) energy provision.
2.	The childhood (pediatric) and the adult human brain takes a very high share of both basal metabolic rate (BMR) (child: 50-70%; adult: ≈20%) and total energy expenditure (TEE) (child: 30-50%; adult: ≈10%).
3.	The pediatric brain for an extended period (≈4-9 years-of-age) consumes roughly 50% more energy than the adult one, and after this, continues during adolescence, at a high but declining rate. Within the brain, childhood cerebral gray matter has an even higher 1.9 to 2.2-fold increased energy consumption. 
4.	This metabolic expensiveness is due to (i) the high cost of synapse activation (74% of brain energy expenditure in humans), combined with (ii), a prolonged period of exuberance in synapse numbers (up to double the number present in adults). Cognitive development during this period associates with volumetric changes in gray matter (expansion and contraction due to metabolic related size alterations in glial cells and capillary vascularization), and in white matter (expansion due to myelination). 
5.	Amongst mammals, anatomically modern humans show an unique pattern in which very slow musculoskeletal body growth is followed by a marked adolescent size/stature spurt. This pattern of growth contrasts with nonhuman primates that have a sustained fast juvenile growth with only a minor period of puberty acceleration. The existence of slow childhood growth in humans has been shown to date back to 160,000 BP. 
6.	Human children physiologically have a limited capacity to protect the brain from plasma glucose fluctuations and other metabolic disruptions. These can arise in adults, during prolonged strenuous exercise when skeletal muscle depletes plasma glucose, and produces other metabolic disruptions upon the brain (hypoxia, hyperthermia, dehydration and hyperammonemia). These are proportional to muscle mass.
7.	Children show specific adaptations to minimize such metabolic disturbances. (i) Due to slow body growth and resulting small body size, they have limited skeletal muscle mass. (ii) They show other adaptations such as an exercise specific preference for free fatty acid metabolism. (iii) While children are generally more active than adolescents and adults, they avoid physically prolonged intense exertion. 
8.	Childhood has a close relationship to high levels of energy provision and metabolic adaptations that support prolonged synaptic neurodevelopment. 
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Explaining semantic short-term memory deficits:evidence for the critical role of semantic control

Patients with apparently selective short-term memory (STM) deficits for semantic information have played an important role in developing multi-store theories of STM and challenge the idea that verbal STM is supported by maintaining activation in the language system. We propose that semantic STM deficits are not as selective as previously thought and can occur as a result of mild disruption to semantic control processes, i.e., mechanisms that bias semantic processing towards task-relevant aspects of knowledge and away from irrelevant information. We tested three semantic STM patients with tasks that tapped four aspects of semantic control: (i) resolving ambiguity between word meanings, (ii) sensitivity to cues, (iii) ignoring irrelevant information and (iv) detecting weak semantic associations. All were impaired in conditions requiring more semantic control, irrespective of the STM demands of the task, suggesting a mild, but task-general, deficit in regulating semantic knowledge. This mild deficit has a disproportionate effect on STM tasks because they have high intrinsic control demands: in STM tasks, control is required to keep information active when it is no longer available in the environment and to manage competition between items held in memory simultaneously. By re-interpreting the core deficit in semantic STM patients in this way, we are able to explain their apparently selective impairment without the need for a specialised STM store. Instead, we argue that semantic STM patients occupy the mildest end of spectrum of semantic control disorders

Economic, Neurobiological and Behavioral Perspectives on Building America's Future Workforce

A growing proportion of the U.S. workforce will have been raised in disadvantaged environments that are associated with relatively high proportions of individuals with diminished cognitive and social skills. A cross-disciplinary examination of research in economics, developmental psychology, and neurobiology reveals a striking convergence on a set of common principles that account for the potent effects of early environment on the capacity for human skill development. Central to these principles are the findings that early experiences have a uniquely powerful influence on the development of cognitive and social skills, as well as on brain architecture and neurochemistry; that both skill development and brain maturation are hierarchical processes in which higher level functions depend on, and build on, lower level functions; and that the capacity for change in the foundations of human skill development and neural circuitry is highest earlier in life and decreases over time. These findings lead to the conclusion that the most efficient strategy for strengthening the future workforce, both economically and neurobiologically, and for improving its quality of life is to invest in the environments of disadvantaged children during the early childhood years.

Executive function and physical activity in preschool children from low-income settings in South Africa

Executive function (EF), that shows rapid development in the preschool years, is foundational for cognitive development. Previous research has found aspects of physical development including gross motor skills and physical activity to be related to EF. However, evidence for these relationships in the preschool years, as well as in low- and middle-income countries is lacking. Therefore, this study aimed to investigate the relationships between EF (and related components of cognitive development) with physical activity and gross motor skills (GMS) in a sample of preschool children from urban and rural low-income settings in South Africa. Cognitive and physical outcomes were measured in a sample of preschool children (N=129; Mage = 50.7±8.3 months; 52.7% girls) from urban (Soweto) and rural (Bushbuckridge) low-income settings in South Africa. Cognitive components included EF, self-regulation (Early Years Toolbox, EYT), attention (adapted visual search task) and school readiness (Early Childhood Development Criteria Test). Physical outcomes included objectively measured physical activity (accelerometry), gross motor skills (Test for Gross Motor Development 2) and anthropometric measurements (height and weight). On average, children from both settings showed higher than expected scores for EF and self-regulation (based on Australian norms for the EYT), adequate gross motor proficiency and high volumes of physical activity (M total physical = 476 minutes per day). In contrast, a high proportion of children, particularly in the rural setting, demonstrated below average scores for school readiness. Investigations into the relationships revealed that EF was positively associated with self-regulation, attention and school readiness. Positive associations were also found between GMS and physical activity and, and physical activity and body mass index (BMI). And finally, that GMS, but not physical activity, was positively associated with all components of cognitive development. This study is the first to provide evidence for the importance of EF and the link between motor and cognitive development in preschool children from South African, low-income settings. Another key finding was that there may be factors promoting early EF skills in these settings but that these skills, although associated, are not transferring to school readiness. The lack of (or negative) associations between physical activity and cognition presents another key finding, further research is needed to identify whether there are specific amounts and types of physical activity that specifically benefit cognitive development

Keeping Mind in Mind : Parental Reflective Functioning and Executive Functioning in Mothers with Substance Use Disorder

There is a consensus that having a substance use disorder may adversely affect caregiving capacities. Parental reflective functioning (PRF) and executive functioning (EF) are both important capacities for sensitive parenting as well as often being impaired in SUD mothers. Although there are increasing interest in cognitive components underlying mentalizing capacities, no studies have previously investigated associations between PRF and EF in SUD mothers. Therefore, the first aim of this study (Paper I) was to investigate if PRF was associated with EF. We controlled for mental health status and IQ, factors known to associate with both PRF and EF. Our findings supported an association between PRF and EF, but the significant association was diminished after introducing mental health status as a control variable. However, when the group of mothers were divided in two based on PRF level, mothers with adequate PRF exhibited significantly better working memory, cognitive flexibility and planning capacities compared to mothers with poor PRF, even after controlling for mental health status and intelligence (IQ). In addition, mothers with poor PRF started using substances and developed a dependency significantly earlier than mothers with adequate PRF. These findings elucidate the association between particular EF components and PRF in mothers with SUD. Compromised EF and PRF are both known to be associated with heightened stress levels. Mothers with SUD exhibit high levels of stress, as well as difficulties in stress-regulation. The second aim of the study (Paper II) was therefore to investigate how EF components (working memory, inhibition and cognitive flexibility) associated with different forms of stress (parental stress, general life stress and psychological distress), and if PRF mediated the association between EF and stress. Results demonstrated that cognitive flexibility significantly contributed to variance in parental stress, while working memory contributed to variance in psychological distress. PRF mediated the relationship between EF and parental stress, while the association between EF and psychological distress was partially mediated by PRF. As far as we know, this study is the first to demonstrate the mediating effect of PRF between EF and experience of stress. The result indicate that a well-functioning PRF and reflection around the experience of stress might heighten access to EF in SUD mothers. Dysregulated levels of stress in adulthood have been associated with experiences of adversity in childhood. Adaptive childhood experiences, on the other hand, are known to enhance resilience. Mothers with SUD have a heightened likelihood of having experienced different types of adversity during childhood and adolescence, and often report low levels of adaptive childhood experiences. The third aim of this study (Paper III) was therefore to explore how different types of adversity (emotional, physical and sexual abuse and neglect) and adaptive experiences (safety and competence) in different developmental phases (early childhood, latency and adolescence) were associated with PRF, when we controlled for mental health status and EF. Results showed that only adaptive experiences in early childhood significantly explained variance in PRF. Mental health status also contributed to variance in PRF, indicating that mothers with more adaptive experiences in early childhood had better mental health status in adulthood, which in combination related to higher PRF. Mothers who reported absence of substantial adaptive experiences in early childhood exhibited lower PRF. Amongst the types of adversities, experiences of emotional abuse during childhood and adolescence stood out as contributing to deficits in PRF more than other types of adversities. In addition, EF contributed significantly to variance in PRF. The results indicated that mothers with less experience of emotional abuse had better EF, which in combination related to higher PRF. Moreover, compared to mothers with negative to low PRF, mothers with adequate PRF had more adaptive and less adverse experiences in the different developmental phases assessed. Our results indicate that PRF might have developmental trajectories. The results in this study may give further knowledge about possible intergenerational risk and resilience. Findings in these studies indicate that development of effective interventions for mothers with SUD should have a dual focus on PRF and EF when targeting stress, dynamic intergenerational risk factors, and sensitive caregiving capacities. The considerable heterogeneity in the group of mothers stresses the importance of individually adjusted interventions in accordance with capacities and vulnerabilities to better target capacities important for sensitive caregivin

Human metabolic adaptations and prolonged expensive neurodevelopment: A review

1.	After weaning, human hunter-gatherer juveniles receive substantial (≈3.5-7 MJ day^-1^), extended (≈15 years) and reliable (kin and nonkin food pooling) energy provision.
2.	The childhood (pediatric) and the adult human brain takes a very high share of both basal metabolic rate (BMR) (child: 50-70%; adult: ≈20%) and total energy expenditure (TEE) (child: 30-50%; adult: ≈10%).
3.	The pediatric brain for an extended period (≈4-9 years-of-age) consumes roughly 50% more energy than the adult one, and after this, continues during adolescence, at a high but declining rate. Within the brain, childhood cerebral gray matter has an even higher 1.9 to 2.2-fold increased energy consumption. 
4.	This metabolic expensiveness is due to (i) the high cost of synapse activation (74% of brain energy expenditure in humans), combined with (ii), a prolonged period of exuberance in synapse numbers (up to double the number present in adults). Cognitive development during this period associates with volumetric changes in gray matter (expansion and contraction due to metabolic related size alterations in glial cells and capillary vascularization), and in white matter (expansion due to myelination). 
5.	Amongst mammals, anatomically modern humans show an unique pattern in which very slow musculoskeletal body growth is followed by a marked adolescent size/stature spurt. This pattern of growth contrasts with nonhuman primates that have a sustained fast juvenile growth with only a minor period of puberty acceleration. The existence of slow childhood growth in humans has been shown to date back to 160,000 BP. 
6.	Human children physiologically have a limited capacity to protect the brain from plasma glucose fluctuations and other metabolic disruptions. These can arise in adults, during prolonged strenuous exercise when skeletal muscle depletes plasma glucose, and produces other metabolic disruptions upon the brain (hypoxia, hyperthermia, dehydration and hyperammonemia). These are proportional to muscle mass.
7.	Children show specific adaptations to minimize such metabolic disturbances. (i) Due to slow body growth and resulting small body size, they have limited skeletal muscle mass. (ii) They show other adaptations such as an exercise specific preference for free fatty acid metabolism. (iii) While children are generally more active than adolescents and adults, they avoid physically prolonged intense exertion. 
8.	Childhood has a close relationship to high levels of energy provision and metabolic adaptations that support prolonged synaptic neurodevelopment. 
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Inhibitory Control Training

Inhibitory control is a critical neurocognitive skill for navigating cognitive, social, and emotional challenges. It rapidly increases during the preschool period and is important for early cognitive development, as it is a crucial component of executive functioning, self-regulation, and impulsivity. Inhibitory control training (ICT) is a novel intervention in which participants learn to associate appetitive cues with inhibition of behavior. It is being considered a promising approach in the treatment of psychopathology and appetitive behaviors. This book aims to bring together knowledge on the topic, considering research, clinic, and forensic field of intervention. Indeed, this book can be considered an excellent synopsis of perspectives, methods, empirical evidence, and international references