John Kerr and his effects found in 1877 and 1878

John Kerr's famous communications in the Philosophical Magazine in 1877 and 1878 are revisited, interpreted, and illustrated in terms of a present-day view of Kerr spectroscopy and applications thereof.     

Electric transport properties of Pt/Permalloy bilayers in the presence of an external magnetic field

A recent experimental study of the electric properties of Pt/Permalloy bilayers based on a simultaneous application of an in-plane microfrequency current and an external magnetic field is simulated on a fully relativistic ab initio level by considering the resistivity as an implicit function of the free energy. It is found that the oscillations detected experimentally are caused by the different behavior of out-of-plane and in-plane resistivities in the vicinity of that value of the free energy that corresponds to the resonant field induced by the applied current. A necessary precondition for such oscillations is a sizeable perpendicular anisotropy, which is not the case in systems consisting only of Permalloy. It is shown that the observed phenomenon is essentially an interface effect.     

The Seven-Item Short Form of the Dyadic Adjustment Scale: Further Evidence for Construct Validity

Two studies examine psychometric aspects of the seven-item version of the Dyadic Adjustment Scale (DAS) (Spanier, 1976). In Study 1, data from 148 heterosexual clients seeking marital therapy services and 122 heterosexual couples in the community were used to assess the criterion validity of the DAS-7. The measure differentiated between clinic and community participants and between marriages classified as distressed or adjusted based on the full DAS score. In Study 2, the reliability and convergent validity of the DAS7, when administered as a separate scale, was assessed in a community sample of 162 participants who were married or were in cohabiting heterosexual relationships. Obtained values were comparable to those reported in previous research in which the DAS-7 was obtained by extracting items from participants' full DAS. These results demonstrate that the DAS-7 is a psychometrically sound short form for assessing marital adjustment.     

Embodied simulation as part of affective evaluation processes: Task dependence of valence concordant EMG activity

The current studies investigated age-related biases in recall of emotion in older and younger adults. In two prospective–retrospective, Internet-based diary studies, older (aged 65 years and older) and younger participants (aged 18 to 37) reported on their affect at the end of every day. Participants then recalled their affect during the diary rating periods. In both studies, recall bias was assessed by comparing retrospective reports to the prospective diary ratings. Older adults tended to overestimate positive affect more than younger adults, who themselves tended to overestimate negative affect more than older adults, relative to diary ratings. Age-related patterns of recall bias are discussed in light of recent literature on the interface between cognition and emotion in ageing, particularly on increased positivity and reduced negativity effects in emotional processing and recall.     

Collective efficacy following a series of natural disasters

This article examined adolescents' reports of how they cope with a specific social stressor: authority conflict with parents. This situation was presented to 626 adolescents as part of a larger study on coping with stress. Students were requested to report on the intensity of the stress experienced, intensity of emotions, emotion regulation, perceived availability of social support, goal framing, and coping strategies used. Coping strategies split up factor-analytically into two coping patterns, namely fighting the stressor and coming to terms with the stressor. The relations between these two coping modes and various aspects of the students' mental representation of the stressor were examined. It was predicted that the way students frame the coping goal would affect their choice of coping strategies. Direct effects of coping strategy, emotion regulation and social support on intensity of stress were tested as well as moderating effects of the type of coping mode used on the relationship between emotion regulation and experienced stress. It is suggested that some youngsters consider an authority conflict with their parents as a normal aspect of daily functioning, whereas other view it as a developmental challenge.     

Introduction

A dynamic model of affect suggests that positive and negative affect (PA and NA) are normally relatively independent of one another, whereas the heightened apprehensiveness and narrowed cognitive attention in persons with anxiety may contribute to a more unidimensional affect structure. This possibility was examined in a sample of 230 patients seeking treatment for anxiety and depressive disorders in the Netherlands. Two methods, a multiple-group confirmatory factor analysis (CFA) and Fisher's z test of correlations, were used to test these predicted relationships within a sample of persons diagnosed with either a depressive or an anxiety disorder. Both methods supported these predictions, with the depressed group exhibiting relatively independent PA and NA while the anxious group's affects were more strongly inversely correlated.     

Book review

Long-standing beliefs about one's self-efficacy and learning ability accumulate over the school years. Attributions, or causal perceptions and interpretations, of behavioural outcomes are also based on a person's learning history. And, it is evident from research on attributional bias and self-esteem that the perceived causes of success and failure have consequences for academic success. An important perspective on attributions, frequently neglected in educational research, pertains to content-specific beliefs about one's competence. We set up a field study in which students from the first form of secondary education were asked to report their causal attributions of regular school examinations in three school subjects: history, native language, and mathematics. The results suggest that students generate different causal attributions for successful or unsuccessful examinations, belonging to different school-subjects. Perception of specific examination conditions may or may not urge students to generate specific attributions. There is evidence for both school-subject specificity and examination-specificity in the observed causal attributions. But, the effect of school-subject seems to be more pronounced than the effect of examination. Information at the momentary level (examination conditions) interacts with information at the middle level (school-subject). Closer analyses of the observed causal attributions vis-à-vis perceived success and failure in the three school-subjects displayed marked differences, especially in relation to the effort attributions.     

Working and reference memory of pigs (Sus scrofa domesticus) in a holeboard spatial discrimination task: the influence of environmental enrichment

Interest in cognitive research in pigs is increasing, but little is known about the impact of environmental conditions on pigs’ cognitive capabilities. The present study investigated the effect of environmental enrichment on cognitive performance of pigs in a holeboard spatial task, in which they had to discriminate four baited buckets out of 16. Pigs (n = 32) were either housed in stimulus-poor, barren pens, or in larger pens enriched with rooting substrates. Pigs were subjected to 30 holeboard trials. Both working memory (WM), that is, the ratio (baited visits/total number of (re)visits to baited buckets), and reference memory (RM), that is, the ratio ((re)visits to baited buckets/total number of visits to all buckets), improved over trials. WM scores were higher in pigs from enriched pens than in pigs from barren pens. Housing did not affect RM scores. Personality type of the pigs, as assessed early in life using a backtest, did not affect WM or RM. In conclusion, housing conditions of pigs did not affect reference memory, but environmental enrichment improved working memory of pigs in a spatial discrimination task. Based on the findings of this study, we suggest that cognitive functioning of pigs may be impaired under commonly used housing conditions.     

Sleep-amount differentially affects fear-processing neural circuitry in pediatric anxiety: A preliminary fMRI investigation

Insufficient sleep, as well as the incidence of anxiety disorders, both peak during adolescence. While both conditions present perturbations in fear-processing-related neurocircuitry, it is unknown whether these neurofunctional alterations directly link anxiety and compromised sleep in adolescents. Fourteen anxious adolescents (AAs) and 19 healthy adolescents (HAs) were compared on a measure of sleep amount and neural responses to negatively valenced faces during fMRI. Group differences in neural response to negative faces emerged in the dorsal anterior cingulate cortex (dACC) and the hippocampus. In both regions, correlation of sleep amount with BOLD activation was positive in AAs, but negative in HAs. Follow-up psychophysiological interaction (PPI) analyses indicated positive connectivity between dACC and dorsomedial prefrontal cortex, and between hippocampus and insula. This connectivity was correlated negatively with sleep amount in AAs, but positively in HAs. In conclusion, the presence of clinical anxiety modulated the effects of sleep-amount on neural reactivity to negative faces differently among this group of adolescents, which may contribute to different clinical significance and outcomes of sleep disturbances in healthy adolescents and patients with anxiety disorders.     

Megachiropteran bats (Pteropus) utilize human referential stimuli to locate hidden food

Spontaneous point-following behavior has been considered an indicator of advanced social cognition unique to humans. Recently, it has been suggested that a close evolutionary relationship with humans could result in similar social skills in domesticated species. An alternative view is that the mechanism is not genetic domestication alone but instead a combination of phylogenetic and ontogenetic variables. Here we test the necessity of phylogenetic domestication by investigating the point-following behavior of a captive population of nondomesticated megachiropteran bats (Pteropus pumilus, Pteropus rodricensis, Pteropus conspicillatus, Pteropus vampyrus). Three of five subjects were highly successful in following an unfamiliar human's point to a target location, providing the first empirical evidence of cross-species social referencing in bats. The three successful bats were all born in captivity and socialized to humans early in life, whereas unsuccessful bats were wild-born individuals. This study provides evidence that referential point following is not restricted to domesticated animals and indicates that early experience may be important. Megachiropteran bats may prove to be a useful model for studying social behaviors.