The human oncogene beta-catenin is a bifunctional protein with critical roles in both cell adhesion and transcriptional regulation in the Wnt pathway. Wnt/beta-catenin signalling has been implicated in developmental processes as diverse as elaboration of embryonic polarity, formation of germ layers, neural patterning, spindle orientation and gap junction communication, but the ancestral function of beta-catenin remains unclear. In many animal embryos, activation of beta-catenin signalling occurs in blastomeres that mark the site of gastrulation and endomesoderm formation, raising the possibility that asymmetric activation of beta-catenin signalling specified embryonic polarity and segregated germ layers in the common ancestor of bilaterally symmetrical animals. To test whether nuclear translocation of beta-catenin is involved in axial identity and/or germ layer formation in 'pre-bilaterians', we examined the in vivo distribution, stability and function of beta-catenin protein in embryos of the sea anemone Nematostella vectensis (Cnidaria, Anthozoa). Here we show that N. vectensis beta-catenin is differentially stabilized along the oral-aboral axis, translocated into nuclei in cells at the site of gastrulation and used to specify entoderm, indicating an evolutionarily ancient role for this protein in early pattern formation.

The ability to differentiate danger and safety through associative processes emerges early in life. Understanding the mechanisms underlying associative learning of threat and safety can clarify the processes that shape development of normative fears and pathological anxiety. Considerable research has used fear conditioning and extinction paradigms to delineate underlying mechanisms in animals and human adults; however, little is known about these mechanisms in children and adolescents. The current paper summarizes the empirical data on the development of fear conditioning and extinction. It reviews methodological considerations and future directions for research on fear conditioning and extinction in pediatric populations.

Temperamentally exuberant children may be at risk for emotion regulation problems, but this may also depend on their capacity for effortful control. To examine this issue, we assessed 72 typically-developing 3- to 5-year-olds. Child exuberance, effortful control, and emotion regulation were assessed via maternal report and observations of child behavior. Emotion regulation problems were elevated among children showing high exuberance and among children showing low effortful control. However, during a disappointing task, children with high exuberance showed stable, elevated levels of organized emotion regulation regardless of effortful control; for children with low exuberance, only those who also showed high effortful control showed comparable levels of organized emotion regulation. Implications for understanding risk and resilience associated with exuberance are discussed.

Behavioural inhibition is a stable temperamental trait that is identifiable during infancy and toddlerhood and is characterized by fearful reactivity to novelty. Children identified as behaviourally inhibited have been shown to be at increased risk for developing anxiety disorders such as social phobia. The current review addresses the link between behavioural inhibition and the risk for developing anxiety disorders. Research suggests that this risk may be modulated by a number of extrinsic and intrinsic factors. Extrinsic factors include particular parental beliefs, parenting styles, and childrearing contexts. Intrinsic factors include executive function capacities such as attention bias, attention shifting, inhibitory control, and self-monitoring. In the present paper we review the contribution of these factors to the development of anxiety in behaviourally inhibited children.

The current study examined developmental changes in fear learning and generalization in 54 healthy 5–10-year old children using a novel fear conditioning paradigm. In this task, the conditioned stimuli (CS+/CS−) were two blue and yellow colored cartoon bells, and the unconditioned stimulus was an unpleasant loud alarm sound presented with a red cartoon bell. Physiological and subjective data were acquired. Three weeks after conditioning, 48 of these participants viewed the CS−, CS+, and morphed images resembling the CS+. Participants made threat–safety discriminations while appraising threat and remembering the CS+. Although no age-related differences in fear learning emerged, patterns of generalization were qualified by child age. Older children demonstrated better discrimination between the CS+ and CS morphs than younger age groups and also reported more fear to stimuli resembling the CS+ than younger children. Clinical implications and future directions are discussed.

Whether task-irrelevant emotional stimuli facilitate or disrupt attention performance may depend on a range of factors, such as emotion type, task difficulty, and stimulus duration. Few studies, however, have systematically examined the influence of these factors on attention performance. Sixty-three adults, scoring within a normative range for mood and anxiety symptoms, completed either an easy or difficult version of an attention task measuring three aspects of attention performance: alerting, orienting, and executive attention. Results showed that in the easy task only, threatening versus nonthreatening task-irrelevant emotional faces facilitated orienting regardless of stimulus duration. These effects were no longer significant during the difficult condition. When the easy and difficult conditions were examined together, duration effects emerged such that stimuli of longer durations lead to greater interference, although effects were nonlinear. Findings illustrate that threat-relevant emotional stimuli facilitate attention during tasks with low cognitive load, but underscore the importance of considering a range of task parameters. Results are discussed in the context of adaptive and maladaptive emotion-attention interactions.

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