Does HPA‐Axis Dysregulation Account for the Effects of Income on Effortful Control and Adjustment in Preschool Children?

The effects of low income on children's adjustment might be accounted for by disruptions to hypothalamic–pituitary–adrenal (HPA)‐axis activity and to the development of effortful control. Using longitudinal data and a community sample of preschool‐age children (N = 306, 36–39 months) and their mothers, recruited to over‐represent low‐income families, we explored the associations among diurnal cortisol levels and effortful control, and we tested a model in which diurnal cortisol and effortful control account for the effects of family income on child adjustment. Continuous indicators of morning cortisol level and diurnal slope, as well as dichotomous indicators reflecting low morning levels and flat diurnal slope, were examined as predictors of rank‐order changes in two dimensions of effortful control, executive control and delay ability. Low income was related to a flat diurnal cortisol slope, and above the effects of family income, a flat diurnal cortisol slope predicted lower social competence. Low morning cortisol level predicted smaller gains in executive control and higher total adjustment problems. Further, delay ability predicted lower adjustment problems above the effects of income and diurnal cortisol levels. The results suggest that HPA‐axis dysregulation and effortful control contribute additively to children's adjustment. Copyright © 2013 John Wiley & Sons, Ltd.     

Spatial term apprehension with a reference object’s rotation in three-dimensional space

It has been reported that the overall shapes of spatial categorical patterns of projective spatial terms such as above and below are not influenced by the rotation of a reference object on a two-dimensional (2D) upright plane. However, is this also true in three-dimensional (3D) space? This study shows the dynamic aspects of the apprehension of projective spatial terms in 3D space by detailing how the rotation of a reference object with an inherent front influences the apprehension of projective spatial terms on a level plane by mapping their spatial categorical patterns. The experiment was designed to examine how spatial categorical patterns on a level plane changed with the rotation of a reference object with an inherent front in 3D computer graphics space. We manipulated the rotation of a reference object with an inherent front at three levels (0°, 90°, and 180° rotations) and examined how such manipulation changed the overall spatial categorical patterns of four basic Japanese projective spatial terms: mae, ushiro, hidari, and migi (similar to in front of, behind, to the left of, and to the right of in English, respectively). The results show that spatial term apprehension was affected by the rotation of the reference object in 3D space. In particular, rotation influenced the mae–ushiro and hidari–migi systems differently. The results also imply that our understanding of projective spatial terms on a level plane in 3D space is affected dynamically by visual information from 3D cues.     

Worse than sticks and stones? Bullying is associated with altered HPA axis functioning and poorer health

Adolescents (N = 107; M = 12.23 years, SD = 1.09 months) participated in a two-part study examining peer victimization, neuroendocrine functioning, and physical health. In phase 1, adolescents completed questionnaires assessing peer victimization and health. They returned for phase 2 which consisted of two sessions. In session 1, adolescents learned to collect salivary cortisol samples; they collected four samples over 2 non-sports school days. In session 2, adolescents completed the Trier Social Stress Test (TSST) in which they prepared and delivered a speech while cortisol was collected. Peer victimization predicted poor health outcomes and a flattened cortisol awakening response (CAR); this CAR was linked with health problems. During the TSST, victims reported more stress and exhibited altered cortisol levels. Higher cortisol immediately after the stressor and lower cortisol 30 min after the stressor were associated with more health problems. This study provides evidence that the relationship between peer victimization and poor physical health may be explained by differences in neuroendocrine functioning.     

Investigations of HPA function and the enduring consequences of stressors in adolescence in animal models

Developmental differences in hypothalamic–pituitary–adrenal (HPA) axis responsiveness to stressors and ongoing development of glucocorticoid-sensitive brain regions in adolescence suggest that similar to the neonatal period of ontogeny, adolescence may also be a sensitive period for programming effects of stressors on the central nervous system. Although research on this period of life is scarce compared to early life and adulthood, the available research indicates that effects of stress exposure during adolescence differ from, and may be longer-lasting than, effects of the same stress exposure in adulthood. Research progress in animal models in this field is reviewed including HPA function and the enduring effects of stress exposures in adolescence on sensitivity to drugs of abuse, learning and memory, and emotional behaviour in adulthood. The effects of adolescent stress depend on a number of factors, including the age, gender, the duration of stress exposure, the type of stressor, and the time between stress exposure and testing.     

The relation between preparatory stance and trunk rotation movements

The influence of preparatory stance on rotation movement reaction time of the trunk by bending of the knee and hip joint(s) was examined in 12 subjects. Four preparatory stances were examined: straight knee and hip extension (STAND), slight flexion of knee joints and hip joint (LIGHT), deep flexion (DEEP), and free initial position, i.e. that felt to be the most comfortable and effective (FREE). There was no significant influence of the preparatory stance on hip latency, but there were significant differences between the preparatory stances on response time (RT) and movement time (MT). Furthermore, using a quadratic curve fitting technique, knee joint angles of 24.8 degrees and a hip joint angle of 23.3 degrees were shown to be the optimum flexion angles in the preparatory stance for the initiation of quick trunk rotation movements. It is proposed that mechanical factors have considerably more effects on trunk rotation movements than does the nervous system.