The glucocorticoid contribution to obesity

Obesity is fast becoming the scourge of our time. It is one of the biggest causes of death and disease in the industrialized world, and affects as many as 32% of adults and 17% of children in the USA, considered one of the world's fattest nations. It can also cost countries billions of dollars per annum in direct and indirect care, latest estimates putting the USA bill for obesity-related costs at $147 billion in 2008. It is becoming clear that the pathophysiology of obesity is vastly more complicated than the simple equation of energy in minus energy out. A combination of genetics, sex, perinatal environment and life-style factors can influence diet and energy metabolism. In this regard, psychological stress can have significant long-term impact upon the propensity to gain and maintain weight. In this review, we will discuss the ability of psychological stress and ultimately glucocorticoids (GCs) to alter appetite regulation and metabolism. We will specifically focus on (i) GC regulation of appetite and adiposity, (ii) the apparent sexual dimorphism in stress effects on obesity and (iii) the ability of early life stress to programme obesity in the long term.     

Stronger neural dynamics capture changes in infants' visual working memory capacity over development

Visual working memory (VWM) capacity has been studied extensively in adults, and methodological advances have enabled researchers to probe capacity limits in infancy using a preferential looking paradigm. Evidence suggests that capacity increases rapidly between 6 and 10 months of age. To understand how the VWM system develops, we must understand the relationship between the looking behavior used to study VWM and underlying cognitive processes. We present a dynamic neural field model that captures both real-time and developmental processes underlying performance. Three simulation experiments show how looking is linked to VWM processes during infancy and how developmental changes in performance could arise through increasing neural connectivity. These results provide insight into the sources of capacity limits and VWM development more generally.     

Corresponding delay-dependent biases in spatial language and spatial memory

The present study addresses the relationship between linguistic and non-linguistic spatial representations. In three experiments we probe spatial language and spatial memory at the same time points in the task sequence. Experiments 1 and 2 show analogous delay-dependent biases in spatial language and spatial memory. Experiment 3 extends this correspondence, showing that additional perceptual structure along the vertical axis reduces delay-dependent effects in both tasks. These results indicate that linguistic and non-linguistic spatial systems depend on shared underlying representational processes. In addition, we also address how these delay-dependent biases can arise within a single theoretical framework without positing differing prototypes for linguistic and non-linguistic spatial systems.     

The influence of heightened body‐awareness on walking through apertures

The reported study measured the ratio between aperture‐width and hip‐width that marked the critical transition from frontal walking to body rotation for male and female participants. Half of the participants of each sex wore form‐fitting lycra clothes and half loose‐fitting jogging suits. Participants wearing the form‐fitting clothing reported heightened body awareness relative to those wearing the loose‐fitting clothing. For male participants this difference was reflected in a smaller aperture‐to‐hip ratio in the form‐fitting than loose‐fitting clothing condition. That is, males walked frontally through smaller apertures when wearing form‐fitting than when wearing loose‐fitting clothing. For females there was no difference in walking action as a function of clothing style. Results are discussed in terms of the perception of action opportunities in the environment, the influence of body awareness on such perception and sex differences. Copyright © 2009 John Wiley & Sons, Ltd.     

Effects of anesthetic agents on socially transmitted olfactory memories in mice

Mice can learn a food preference from odor cues transmitted on the breath of a conspecific, even if the “demonstrator” is anesthetized. To our knowledge there are no studies examining the effect of anesthetizing the “observer” on development of memory for socially transmitted food preferences (STFP). In Experiment 1 we found that 2–4 month-old F2 C57Bl/6x129sv male and female mice demonstrated a STFP after a 5 min exposure to an anesthetized demonstrator mouse when tested 24 h later. In Experiment 2, observer mice anesthetized with Sagatal (60 mg/kg) prior to the “social interaction” preferentially avoided the cued food when tested 24 h later. This aversion was not due to any overt aversive effects of this dose of Sagatal because mice that ate the food and were then anesthetized, or could only smell the food for 5 min while anesthetized, showed no preference or aversion. In a third experiment we found that the Sagatal-induced aversion was not a general property of anesthesia because there were varied results produced by observer mice treated with anesthetic drugs with different mechanisms of action. Vetalar (200 mg/kg) and Rompun (10 mg/kg) treated animals ate similar amounts of cued and non-cued food at test, indicating an absence of learning. Hypnorm (0.5 ml/kg) treated animals showed a preference for the cued food whereas those treated with Hypnovel (2.5 ml/kg) showed an aversion to the cued food. These results show that the food aversion observed with Sagatal is not a general property of anesthetic agents, but appears to be restricted to those acting primarily on the GABAergic system. Thus, we have shown that under certain conditions it is possible for an anesthetized observer mouse to learn a preference or aversion of a socially-linked olfactory cue.     

Feedforward, -backward,and neutral transparency measures for Grade 1 and Grade 2 Greek readers

In the present study, orthographic metrics for Greek children’s Grade 1 and Grade 2 reading materials were presented. Data for five transparency metrics—three of which being neither feedforward nor feedbackward— were presented and offered for use in the research of children’s reading and spelling acquisition. The analysis demonstrated the complex relationships between metrics and compared the results with those obtained for the English language. The structure of these metrics from a variety of corpus sizes was investigated, and we concluded that large corpus sizes do not necessarily make a substantial contribution to the value of such metrics when compared with smaller samples.     

From Theory to Intervention: Mapping Theoretically Derived Behavioural Determinants to Behaviour Change Techniques

Theory provides a helpful basis for designing interventions to change behaviour but offers little guidance on how to do this. This paper aims to illustrate methods for developing an extensive list of behaviour change techniques (with definitions) and for linking techniques to theoretical constructs. A list of techniques and definitions was generated from techniques published in two systematic reviews, supplemented by "brainstorming" and a systematic search of nine textbooks used in training applied psychologists. Inter-rater reliability of extracting the techniques and definitions from the textbooks was assessed. Four experts judged which techniques would be effective in changing 11 theoretical constructs associated with behaviour change. Thirty-five techniques identified in the reviews were extended to 53 by brainstorming and to 137 by consulting textbooks. Agreement for the 53 definitions was 74.7 per cent (15.4% cells completed and 59.3% cells empty for both raters). Agreement about the link between the 35 techniques and theoretical constructs was 71.7 per cent of 385 judgments (12.2% agreement that effective and 59.5% agreement that not effective). This preliminary work demonstrates the possibility of developing a comprehensive, reliable taxonomy of techniques linked to theory. Further refinement is needed to eliminate redundancies, resolve uncertainties, and complete technique definitions.     

The Effects of Incentives on Visual–Spatial Working Memory in Children with Attention-deficit/Hyperactivity Disorder

Working memory is one of several putative core neurocognitive processes in attention-deficit/hyperactivity disorder (ADHD). The present work seeks to determine whether visual–spatial working memory is sensitive to motivational incentives, a laboratory analogue of behavioral treatment. Participants were 21 children (ages 7–10) with a diagnosis of ADHD-combined type. Participants completed a computerized spatial span task designed to assess storage of visual–spatial information (forward span) and manipulation of the stored information (backward span). The spatial span task was completed twice on the same day, once with a performance-based incentive (trial-wise feedback and points redeemable for prizes) and once without incentives. Participants performed significantly better on the backward span when rewarded for correct responses, compared to the no incentive condition. However, incentives had no effect on performance during the forward span. These findings may suggest the use of motivational incentives improved manipulation, but not storage, of visual–spatial information among children with ADHD. Possible explanations for the differential incentive effects are discussed, including the possibility that incentives prevented a vigilance decrement as task difficulty and time on task increased.