Functional specificity of the visual word form area: general activation for words and symbols but specific network activation for words

The functional specificity of the brain region known as the Visual Word Form Area (VWFA) was examined using fMRI. We explored whether this area serves a general role in processing symbolic stimuli, rather than being selective for the processing of words. Brain activity was measured during a visual 1-back task to English words, meaningful symbols (e.g., $, %), digits, words in an unfamiliar language (Hebrew), and geometric control stimuli. Mean activity in the functionally defined VWFA, as well as a pattern of whole-brain activity identified using a multivariate technique, did not differ for words and symbols, but was distinguished from that seen with other stimuli. However, functional connectivity analysis of this region identified a network of regions that was specific to words, including the left hippocampus, left lateral temporal, and left prefrontal cortex. Results support the hypothesis that activity in the VWFA plays a general role in processing abstract stimuli; however, the left VWFA is part of a unique network of brain regions active only during the word condition. These findings suggest that it is the neural "context" of the VWFA, i.e., the broader activity distributed in the brain that is correlated with VWFA, that is specific for visual word representation, not activity in this brain region per se.     

The Role of Neurobiological Deficits in Childhood Antisocial Behavior

ABSTRACT— Childhood-onset antisocial behavior is an important predictor of chronic and serious forms of antisocial behavior in later life. Both biological and social factors are involved in the development of abnormal behavior. We examine the underlying role of stress-response systems in the link between early social adversity and juvenile antisocial behavior, and propose that children with genetically and/or perinatally based neurobiological deficits have problems in activating these systems and therefore experience difficulties in regulating affect and behavior. Underactivity or attenuated reactivity of the stress-response systems may predispose antisocial individuals to seek out stimulation or take risks, and thereby explain deficits in learning and socialization. Further investigations of neurobiological functioning in antisocial children might not only indicate which children are more likely to persist in behaving antisocially but also guide the development of new interventions.     

Young children's performance on the balance scale: the influence of relational complexity

Three experiments investigated the effect of complexity on children's understanding of a beam balance. In nonconflict problems, weights or distances varied, while the other was held constant. In conflict items, both weight and distance varied, and items were of three kinds: weight dominant, distance dominant, or balance (in which neither was dominant). In Experiment 1, 2-year-old children succeeded on nonconflict-weight and nonconflict-distance problems. This result was replicated in Experiment 2, but performance on conflict items did not exceed chance. In Experiment 3, 3- and 4-year-olds succeeded on all except conflict balance problems, while 5- and 6-year-olds succeeded on all problem types. The results were interpreted in terms of relational complexity theory. Children aged 2 to 4 years succeeded on problems that entailed binary relations, but 5- and 6-year-olds also succeeded on problems that entailed ternary relations. Ternary relations tasks from other domains--transitivity and class inclusion--accounted for 93% of the age-related variance in balance scale scores.     

A structural model for surface-enhanced stabilization in some metallic glass formers

A structural model for surface-enhanced stabilization in some metallic glass formers is proposed. In this model, the alloy surface structure is represented by five-layer Kagomé-net-based lateral ordering. Such surface structure has intrinsic abilities to stabilize icosahedral-like short-range order in the bulk, acting as ‘a cloak of liquidity’. In particular, recent experimental observations of surface-induced lateral ordering and a very high glass forming ability of the liquid alloy Au₄₉Ag_5.5Pd_2.3Cu_26.9Si_16.3 can be united using this structural model. This model may be useful for the interpretation of surface structure of other liquid alloys with a high glass forming ability. In addition, it suggests the possibility of guiding the design of the surface coating of solid containers for the stabilization of undercooled liquids.     

Why is the receipt of social support associated with increased psychological distress? an examination of three hypotheses

Abstract

Although there is a great deal of research linking social support with favourable psychological well-being outcomes a number of contradictory findings have been published showing support to be associated with increased psychological distress. These contrary findings arise when social support is measured as the receipt of supportive behavior rather than perceptions of support availability and quality. This paper examines three hypotheses that have been advanced to explain why the receipt of support is associated with distress. The first of these hypotheses (the support mobilisation hypothesis) argues that the relationship is a spurious one, and that it is a product of distressing circumstances which increase both support receipt and psychological distress. The other two hypotheses (the inequity hypothesis and the esteem threat hypothesis) both argue that receiving support actually causes distress. We tested these hypotheses in two samples. One sample was a group of individuals who reported having some form of disability (N = 106). the other sample was a 'healthy' comparison group (N = 134). Our analyses showed that in both groups the receipt of support was significantly and positively related to reports of anxiety, but not to reports of depression. Among the 'healthy' sample, controlling for subjects' sex largely explained the positive association between support receipt and anxiety. This was not the case among the 'disabled sample, where the inequity hypothesis received the strongest support. The implications of these findings for interventions based around the provision of social support are examined.     

Conditional discrimination in young children: the roles of associative and relational processing

Two experiments examined conditional discrimination in 4- to 6-year-olds. Children learned to choose one of two objects (e.g., circle) when the background was, say, red and to choose the other object (e.g., triangle) when the background was, say, blue. Awareness was assessed and interpreted as a marker of relational processing. In Experiment 1, most 4- and 5-year-olds did not reach the learning criterion. Children in Experiment 2 solved simpler reversal learning problems before the conditional discrimination problems. Most 4- to 6-year-olds reached criterion, but they did not necessarily demonstrate awareness, suggesting that reversal learning and conditional discrimination can be acquired through associative or relational processing. Relational processing increased with age and was used more on simpler problems. Fluid intelligence predicted Problem 2 performance in children who used relational (not associative) processing on Problem 1. Prior experience with simpler problems and awareness of relational structure are influential in children's conditional discrimination.