Observation of strain distributions in partially relaxed In0.2Ga0.8As on GaAs using electron channelling contrast imaging

Electron channelling contrast imaging (ECCI) has been used to image misfit dislocations between single epitaxial layers (epilayers) of In0.2Ga0.8As grown on GaAs (001). Bulk specimens of the as-grown material were examined over a range of epilayer thickness from 25 to 3000 nm. Spectral analysis of ECCI intensity traces was used to establish whether strain fields from the individual dislocations overlapped. Significant overlapping of strain fields was first observed at an epilayer thickness of 100 nm which corresponds well to the onset of macroscopic strain relaxation.     

The effects of stimulus size on bisection judgements in near and far space

Primate data suggest that near (peripersonal) and far (extrapersonal) space are coded within distinct representations. Support for this claim has been gained from human studies of line bisection, many of which have focused on neuropsychological, rather than normative, samples. One important aspect of these bisection studies has been to control for the changes in angular extent of stimuli that normally accompany changes in viewing distance. The control of angular information, however, requires alterations in the linear dimensions (actual stimulus size) of stimuli. We report two experiments in which normal subjects made manual bisection judgements on stimuli positioned in near or far space, and which were oriented in either the left-right (Experiment 1) or radial plane (Experiment 2). Both experiments were designed to enable the separable effects of linear and angular extent to be disentangled. Viewing distance effects were obtained when angular information was controlled, but many of these were dependent on changes in linear extent, and were only apparent at the individual subject level. Our data confirm that genuine near/far effects may be observed in normative bisection, but that many previous studies which appeared to support a near/far distinction in both normal and brain-damaged bisection behaviour may reflect a failure to control for changes in stimulus size.     

A reproductive threat-based model of evolved sex differences in jealousy

Although heterosexual women and men consistently demonstrate sex differences in jealousy, these differences disappear among lesbians and gay men as well as among heterosexual women and men contemplating same-sex infidelities (infidelities in which the partner and rival are the same sex). Synthesizing these past findings, the present paper offers a reproductive threat-based model of evolved sex differences in jealousy that predicts that the sexes will differ only when the jealous perceivers' reproductive outcomes are differentially at risk. This model is supported by data from a web-based study in which lesbians, gay men, bisexual women and men, and heterosexual women and men responded to a hypothetical infidelity scenario with the sex of the rival randomly determined. After reading the scenario, participants indicated which type of infidelity (sexual versus emotional) would cause greater distress. Consistent with predictions, heterosexual women and men showed a sex difference when contemplating opposite-sex infidelities but not when contemplating same-sex infidelities, whereas lesbians and gay men showed no sex difference regardless of whether the infidelity was opposite-sex or same-sex.     

Growth functions for rapid remembering

Children between ages 9 and 13 were tested for recognizing and remembering words from 6- and 12-word lists. Opportunities for using deliberate mnemonics were severely restricted. Developmental functions showed different growth patterns for remembering the items in a short list than for remembering order, and different patterns for storing items from a long list than for retrieving them. However, none of these functions was parallel to the growth function of rapid word recognition. This absence of parallel growth contradicted a hypothesis that memory develops when item recognition develops. The data suggested, instead, that modest but reliable gains in rapid processes of storage and retrieval contribute to memory development during middle childhood.     

How do we understand empathy systemically?

This paper considers what a systemic understanding of empathy might be in the context of recent developments in systemic approaches. Clinical work is the basis for an exploration of which systemic ideas might be useful in thinking about 'systemic empathy'. The question of whether empathy is inherent in the systemic approach is considered.     

Pigeons discriminate objects on the basis of abstract familiarity

Knowledge of previous encounters with conspecifics is thought to be beneficial as it allows fast and appropriate behavioral responses toward those animals. This level of categorization goes beyond perceptual similarity and requires the individual to refer to a more abstract common referent, namely familiarity. It has been shown that pigeons are able to form functional classes of conspecifics that are based on familiarity. To date, we do not know whether this ability is restricted to the social context (including heterospecifics) or if it can also be used to classify inanimate objects. Furthermore, the factors influencing the formation of this functional class are still unknown. Here, we show that pigeons (Columba livia) are able to use a categorical rule of familiarity to classify previously unseen photographs of objects from their living environment. Pigeons that lacked real-life experience with the objects were not able to do so. This suggests that perceptual features alone were not sufficient for class recognition. To investigate the impact of additional functional properties of the objects, familiar objects were further divided into two subcategories, namely those that were considered functionally relevant to the birds and those that were not. Although the majority of pigeons learned to categorize photographs of objects based on familiarity alone, our results also suggest an unlearned preference for “relevant” familiar objects. The results presented here suggest that pigeons are able to learn to extract the discriminative feature of abstract familiarity from pictures by referring to previous real-life experience but that additional functions of objects lead to a preference of these objects.     

Picture–object recognition in the tortoise Chelonoidis carbonaria

To recognize that a picture is a representation of a real-life object is a cognitively demanding task. It requires an organism to mentally represent the concrete object (the picture) and abstract its relation to the item that it represents. This form of representational insight has been shown in a small number of mammal and bird species. However, it has not previously been studied in reptiles. This study examined picture–object recognition in the red-footed tortoise (Chelonoidis carbonaria). In Experiment 1, five red-footed tortoises were trained to distinguish between food and non-food objects using a two-alternative forced choice procedure. After reaching criterion, they were presented with test trials in which the real objects were replaced with color photographs of those objects. There was no difference in performance between training and test trials, suggesting that the tortoises did see some correspondence between the real object and its photographic representation. Experiment 2 examined the nature of this correspondence by presenting the tortoises with a choice between the real food object and a photograph of it. The findings revealed that the tortoises confused the photograph with the real-life object. This suggests that they process real items and photographic representations of these items in the same way and, in this context, do not exhibit representational insight.     

Sexuality and corrections: An administrator’s perspective

Any consideration of human sexuality inevitably refers to fundamental and powerful physical, psychological, behavioral, attitudinal, and social forces that permeate many important aspects of human life and culture. As with many issues impacting society in general, these become magnified within the correctional environment.     

Feeling socially powerless makes you more prone to bumping into things on the right and induces leftward line bisection error

Social power affects the manner in which people view themselves and act toward others, a finding that has attracted broad interest from the social and political sciences. However, there has been little interest from those within cognitive neuroscience. Here, we demonstrate that the effects of power extend beyond social interaction and invoke elementary spatial biases in behavior consistent with preferential hemispheric activation. In particular, participants who felt relatively powerless, compared with those who felt more powerful, were more likely to bisect horizontal lines to the left of center, and bump into the right-hand (as opposed to the left-hand) side when walking through a narrow passage. These results suggest that power induces hemispheric differences in visuomotor behavior, indicating that this ubiquitous phenomenon affects not only how we interact with one another, but also how we interact with the physical world.