Self-criticism, low self-esteem, depressive symptoms, and over-evaluation of shape and weight in binge eating disorder patients

Despite the fact that negative self-evaluations are widely considered to be prominent in eating disorders, the role of self-criticism has received little empirical attention. The vast majority of research on the construct of self-criticism has focused on its role as a specific personality vulnerability factor in depression-related phenomena. In this study of 236 patients with binge eating disorder, confirmatory factor analysis supported self-criticism, self-esteem, depressive symptoms, and over-evaluation of shape and weight as distinct, albeit related, constructs. Structural equation modeling demonstrated that the relation between self-criticism and over-evaluation of shape and weight was partly mediated or explained by low self-esteem and depressive symptoms. Continued efforts to understand the role of self-criticism in eating disorders appear warranted.     

Morphological changes in dendritic spines of Purkinje cells associated with motor learning

Experience-dependent changes of spine structure and number may contribute to long-term memory storage. Although several studies demonstrated structural spine plasticity following associative learning, there is limited evidence associating motor learning with alteration of spine morphology. Here, we investigated this issue in the cerebellar Purkinje cells using high voltage electron microscopy (HVEM). Adult rats were trained in an obstacle course, demanding significant motor coordination to complete. Control animals either traversed an obstacle-free runway or remained sedentary. Quantitative analysis of spine morphology showed that the density and length of dendritic spines along the distal dendrites of Purkinje cells were significantly increased in the rats that learned complex motor skills compared to active or inactive controls. Classification of spines into shape categories indicated that the increased spine density and length after motor learning was mainly attributable to an increase in thin spines. These findings suggest that motor learning induces structural spine plasticity in the cerebellar Purkinje neurons, which may play a crucial role in acquiring complex motor skills.     

Overvaluation of shape and weight among overweight children and adolescents with loss of control eating

Little is known about the phenomenology of pediatric loss of control (LOC) eating. Overvaluation of shape and weight, however, appears to be diagnostically meaningful among binge eating adults. We explored the significance of shape and weight overvaluation among children and adolescents with LOC eating. Participants (n = 526) included 149 overweight youth with LOC eating and 377 overweight controls (CON). Participants were categorized as those reporting at least moderate overvaluation (LOC-Mod, n = 74; CON-Mod, n = 106) or less than moderate overvaluation (LOC-Low, n = 75; CON-Low, n = 271), and compared on measures of eating-related and general psychopathology. LOC-Mod evidenced lower self-esteem than CON-Low, and greater behavioral problems than CON-Mod and CON-Low, but did not differ from LOC-Low in these domains. With the exception of LOC-Low and CON-Mod, all groups differed on global eating-disorder severity, with LOC-Mod scoring the highest. Overvaluation of shape and weight appears to be of questionable importance in defining subtypes of youth with LOC eating. However, as overvaluation and LOC eating each independently predicts eating-disorder onset, their confluence may confer even further risk for eating-disorder development. Longitudinal studies should address this possibility. Developmentally appropriate discussion about body image disturbance may be indicated in interventions targeting pediatric LOC eating and/or obesity.     

Development of preferences for the human body shape in infancy

Two studies investigated the development of infants' visual preferences for the human body shape. In Study 1, infants of 12, 15 and 18 months were tested in a standard preferential looking experiment, in which they were shown paired line drawings of typical and scrambled bodies. Results indicated that the 18-month-olds had a reliable preference for the scrambled body shapes over typical body shapes, while the younger infants did not show differential responding. In Study 2, 12- and 18-month-olds were tested with the same procedure, except that the typical and scrambled body stimuli were photographic images. The results of Study 2 again indicated that only the 18-month-olds had a reliable preference for the scrambled body shapes. This finding contrasts sharply with infants' precocious preferences for human faces, suggesting that infants' learning about human faces and human bodies follow different developmental trajectories.     

The Epistemological Status of Vision and its Implications for Design

Computational theories of vision typically rely on the analysis of two aspects of human visual function: (1) object and shape recognition (2) co-calibration of sensory measurements. Both these approaches are usually based on an inverse-optics model, where visual perception is viewed as a process of inference from a 2D retinal projection to a 3D percept within a Euclidean space schema. This paradigm has had great success in certain areas of vision science, but has been relatively less successful in understanding perceptual representation, namely, the nature of the perceptual encoding. One of the drawbacks of inverse-optics approaches has been the difficulty in defining the constraints needed to make the inference computationally tractable (e.g. regularity assumptions, Bayesian priors, etc.). These constraints, thought to be learned assumptions about the nature of the physical and optical structures of the external world, have to be incorporated into any workable computational model in the inverse-optics paradigm. But inference models that employ an inverse optics plus structural assumptions approach inevitably result in a naïve realist theory of perceptual representation. Another drawback of inference models for theories of perceptual representation is their inability to explain central features of the visual experience. The one most evident in the process and visual understanding of design is the fact that some visual configurations appear, often spontaneously, as perceptually more coherent than others. The epistemological consequences of inferential approaches to vision indicate that they fail to capture enduring aspects of our visual experience. Therefore they may not be suited to a theory of perceptual representation, or useful for an understanding of the role of perception in the design process and product.     

Some Aspects of Product Shape in Mechanical Engineering

The paper examines some of the many factors that influence the shape of designed products in the mechanical engineering industries. It is shown that, once the detailed shape of a product has been determined, the analysis of that shape from the viewpoints of various engineering activities downstream of design leads to a range of inherently different perceptions of it.     

Estimates of shape by eye, or, The little invariant that could

Five experiments were conducted to test the hypothesis that observers apprehend specific constancies under change in perspective. The constancies were projective properties of ellipses pictured to slant and tilt in depth. Observers were asked to reproduce the static upright view of a moving pair of ellipses, using a computer graphics display and interface. Projective invariants for pairs of conics were computed on the observers’ productions. A few experimental conditions revealed near-perfect performance. When pairs of coplanar ellipses were viewed under dynamic transformation in perspective, then invariants calculated on the observers’ productions were a match – in value on average – to the invariants of the transforming ellipse pairs. It is proposed that measures of projective properties afford a family of techniques that can be applied to gauge acuity for complex shapes in the study of visual form perception.     

First interactions between hydrogen and stress-induced reverse transformation of Ni–Ti superelastic alloy

The first dynamic interactions between hydrogen and the stress-induced reverse transformation have been investigated by performing an unloading test on a Ni–Ti superelastic alloy subjected to hydrogen charging under a constant applied strain in the elastic deformation region of the martensite phase. Upon unloading the specimen, charged with a small amount of hydrogen, no change in the behaviour of the stress-induced reverse transformation is observed in the stress-strain curve, although the behaviour of the stress-induced martensite transformation changes. With increasing amount of hydrogen charging, the critical stress for the reverse transformation markedly decreases. Eventually, for a larger amount of hydrogen charging, the reverse transformation does not occur, i.e. there is no recovery of the superelastic strain. The residual martensite phase on the side surface of the unloaded specimen is confirmed by X-ray diffraction. Upon training before the unloading test, the properties of the reverse transformation slightly recover after ageing in air at room temperature. The present study indicates that to change the behaviour of the reverse transformation a larger amount of hydrogen than that for the martensite transformation is necessary. In addition, it is likely that a substantial amount of hydrogen in solid solution more strongly suppresses the reverse transformation than hydrogen trapped at defects, thereby stabilising the martensite phase.